chore(core): merge dev into session subpath fix

Co-authored-by: Devin Oldenburg <devin@logicplanes.com>

.github/workflows/test.yml

@@ -65,7 +65,7 @@ jobs:
 
       - name: Run unit tests
         timeout-minutes: 20
-        run: bun turbo test --output-logs=errors-only --log-order=grouped --log-prefix=task
+        run: bun turbo test --output-logs=errors-only --log-order=grouped --log-prefix=none
         env:
           OPENCODE_EXPERIMENTAL_DISABLE_FILEWATCHER: ${{ runner.os == 'Windows' && 'true' || 'false' }}
 

CONTEXT.md

@@ -24,7 +24,7 @@ A durable chronological instruction that tells the model the newly effective sta
 _Avoid_: System update, system notification, raw text diff
 
 **Context Epoch**:
-The span during which one effective agent's initially rendered **System Context** remains immutable, ending at compaction or another baseline-replacing transition.
+The span during which one initially rendered **System Context** remains the immutable provider-cache baseline, ending at completed compaction, Session movement, or an incompatible context transition that requires a fresh baseline.
 
 **Baseline System Context**:
 The full **System Context** rendered at the start of a **Context Epoch**.
@@ -75,31 +75,28 @@ The host-supplied environment overlay applied by the server when creating a PTY,
 - Each **Context Source** loader returns one coherent typed value. `SystemContext.make(...)` hides that value type so differently typed sources compose uniformly. Its codec compares and stores that value; its pure renderers produce model-visible baseline, update, and removal text only when needed.
 - `SystemContext.initialize(...)` observes a composed **System Context** once and produces a fresh **Baseline System Context** with its **Context Snapshot**.
 - `SystemContext.reconcile(...)` observes a composed **System Context** once and returns exactly one next action: unchanged, updated, replacement ready, or replacement blocked.
-- `SystemContext.replace(...)` represents an explicit baseline-replacing transition such as compaction or model/provider switch; it either produces a fresh generation or reports that replacement is blocked by unavailable admitted context.
-- Context Epoch preparation retries until stable after optimistic revision mismatches so concurrent replacement requests cannot terminate an otherwise valid safe-boundary run.
+- `SystemContext.replace(...)` renders a fresh generation after completed compaction or another baseline-replacing transition; it reports replacement blocked while previously admitted context is unavailable.
 - **Unavailable Context** uses stale-while-revalidate semantics and is distinct from a successfully loaded absence, which may emit removal text.
 - Ordinary **Context Source** loaders return values directly; loaders that intentionally use stale-while-revalidate may explicitly return **Unavailable Context**.
 - Nested project instruction discovery after successful reads remains a follow-up; when implemented, discovered instructions must be admitted durably at the next **Safe Provider-Turn Boundary**.
 - Location-scoped services naturally re-resolve effective context when a moved session next runs in its destination location.
 - Moving a Session clears its active **Context Epoch**, so the destination must initialize a complete baseline before another prompt can promote.
-- Context Epoch initialization is fenced against the authoritative Session Location, so an old-Location runner cannot recreate source context after a concurrent move.
 - Instruction discovery, source identity, persistence, and file loading belong to the instruction service; the **System Context** abstraction only composes effectful producers and renders loaded values.
 - The first instruction-service slice observes global and upward project `AGENTS.md` files as one ordered aggregate **Context Source** at each **Safe Provider-Turn Boundary**.
 - Built-in and instruction context producers register through the **System Context Registry** with stable contribution keys. Plugin-defined context registration and hot-reload lifecycle remain a follow-up built on the same scoped registry seam.
 - Selected-agent available-skill guidance is a **Context Source** composed with Location-wide registry sources immediately before Context Epoch admission. It lists only names and descriptions permitted for that agent; skill bodies and locations are exposed only through the permission-checked `skill` tool.
-- Switching the selected agent requests **Context Epoch** replacement. A switch admitted after the current **Safe Provider-Turn Boundary** applies to the next provider turn while leaving the already-prepared baseline durable. Epoch creation is fenced against the authoritative effective agent, and retries re-observe the current agent.
-- A cross-agent replacement must complete before another provider turn; unavailable admitted context blocks that replacement instead of exposing the previous agent's privileged baseline.
+- The selected agent and model are sampled when a provider turn starts. Changes admitted after that boundary apply to the next provider turn and do not restart the current turn.
+- Selected-agent available-skill guidance remains a **Context Source**. An agent switch that changes that guidance produces a **Mid-Conversation System Message** while preserving the current baseline.
 - Local tool authorization and pending permission requests retain the effective agent of the provider turn that issued the call; a later agent switch cannot change that call's policy.
 - Context source changes never wake idle sessions; the next naturally scheduled **Safe Provider-Turn Boundary** loads and compares current values lazily.
 - Once admitted, a **Mid-Conversation System Message** remains durable even if the following provider attempt fails and is replayed unchanged on retry.
 - **Mid-Conversation System Messages** remain durable Session-message history; normal user-facing transcript surfaces may hide them.
 - The date **Context Source** initially preserves host-local calendar-date behavior; a configured user timezone may replace that default later.
 - A **Context Epoch** begins with one immutable **Baseline System Context**.
-- A **Context Epoch** durably records the effective agent that owns its **Baseline System Context**.
 - A **Baseline System Context** is stored durably and reused verbatim across process restarts within its **Context Epoch**.
 - A **Baseline System Context** durably preserves the exact joined text used for the active provider-cache prefix.
-- Compaction or a model/provider switch starts a new **Context Epoch** because the baseline can be replaced without preserving the prior provider cache.
-- A model/provider switch always starts a new **Context Epoch** while preserving chronological conversation history.
+- Completed compaction starts a new **Context Epoch** on the next provider attempt, folding the current complete **System Context** into a fresh baseline and removing earlier **Mid-Conversation System Messages** from active model history.
+- A model/provider switch preserves the current **Context Epoch** and chronological conversation history; the new selection applies to the next provider turn.
 - **Model Request Options** remain provider-semantic through Catalog resolution. The Session runner maps them into the LLM package's provider-option namespace; the selected protocol adapter alone owns provider wire encoding.
 - **Generation Controls**, protocol-semantic **Model Request Options**, and compatibility request body fields are separate Catalog domains. A shared ingestion adapter partitions legacy and models.dev AI-SDK-shaped options before routing.
 - The **PTY Environment** is a server concern rather than a Core PTY concern. PTY creation merges caller values, then the host overlay, then Core-forced terminal invariants such as `TERM` and `OPENCODE_TERMINAL`.

packages/cli/src/commands/handlers/serve.ts

@@ -27,9 +27,11 @@ export default Runtime.handler(
 
 function listen(hostname: string, port: Option.Option<number>, password: string) {
   if (Option.isSome(port)) return bind(hostname, port.value, password)
-  // Preserve the familiar default when available, but let the OS choose a free
-  // port when another local server already owns 4096.
-  return bind(hostname, 4096, password).pipe(Effect.catch(() => bind(hostname, 0, password)))
+  const next = (port: number): ReturnType<typeof bind> =>
+    bind(hostname, port, password).pipe(
+      Effect.catch((error) => (port === 65_535 ? Effect.fail(error) : next(port + 1))),
+    )
+  return next(4096)
 }
 
 function bind(hostname: string, port: number, password: string) {

packages/core/bunfig.toml

@@ -0,0 +1,2 @@
+[test]
+preload = ["./test/preload.ts"]

packages/core/schema.json

@@ -1,8 +1,8 @@
 {
   "version": "7",
   "dialect": "sqlite",
-  "id": "169a0f0f-d58f-479f-b024-fa1c7b9a09db",
-  "prevIds": ["abd2f920-b822-49af-b8a7-2e48367d424f"],
+  "id": "f14a9b18-8207-487e-a3d3-227e629ba9ad",
+  "prevIds": ["169a0f0f-d58f-479f-b024-fa1c7b9a09db"],
   "ddl": [
     {
       "name": "workspace",
@@ -900,16 +900,6 @@
       "entityType": "columns",
       "table": "session_context_epoch"
     },
-    {
-      "type": "text",
-      "notNull": true,
-      "autoincrement": false,
-      "default": "'build'",
-      "generated": null,
-      "name": "agent",
-      "entityType": "columns",
-      "table": "session_context_epoch"
-    },
     {
       "type": "text",
       "notNull": true,
@@ -930,26 +920,6 @@
       "entityType": "columns",
       "table": "session_context_epoch"
     },
-    {
-      "type": "integer",
-      "notNull": false,
-      "autoincrement": false,
-      "default": null,
-      "generated": null,
-      "name": "replacement_seq",
-      "entityType": "columns",
-      "table": "session_context_epoch"
-    },
-    {
-      "type": "integer",
-      "notNull": true,
-      "autoincrement": false,
-      "default": "0",
-      "generated": null,
-      "name": "revision",
-      "entityType": "columns",
-      "table": "session_context_epoch"
-    },
     {
       "type": "text",
       "notNull": false,

packages/core/script/migration.ts

@@ -45,15 +45,17 @@ async function generate() {
       if (await Bun.file(target).exists()) throw new Error(`Database migration already exists: ${name}`)
       await Bun.write(
         target,
-        renderMigration(name, await Bun.file(path.join(incremental, name, "migration.sql")).text()),
+        await formatTypescript(
+          renderMigration(name, await Bun.file(path.join(incremental, name, "migration.sql")).text()),
+        ),
       )
       await fs.copyFile(path.join(incremental, name, "snapshot.json"), snapshot)
     }
 
     await fs.mkdir(full)
     await drizzle(temporary, full, "schema")
-    await Bun.write(schema, renderSchema(await generatedSql(full)))
-    await Bun.write(registry, renderRegistry(await typescriptMigrations()))
+    await Bun.write(schema, await formatTypescript(renderSchema(await generatedSql(full))))
+    await Bun.write(registry, await formatTypescript(renderRegistry(await typescriptMigrations())))
   } finally {
     await fs.rm(temporary, { recursive: true, force: true })
   }
@@ -76,12 +78,12 @@ async function check() {
 
     await fs.mkdir(full)
     await drizzle(temporary, full, "schema")
-    if ((await Bun.file(schema).text()) !== renderSchema(await generatedSql(full))) {
+    if ((await Bun.file(schema).text()) !== (await formatTypescript(renderSchema(await generatedSql(full))))) {
       throw new Error("Current database schema is stale. Run `bun script/migration.ts` from packages/core.")
     }
 
     const migrations = await typescriptMigrations()
-    if ((await Bun.file(registry).text()) !== renderRegistry(migrations)) {
+    if ((await Bun.file(registry).text()) !== (await formatTypescript(renderRegistry(migrations)))) {
       throw new Error("Database migration registry is stale. Run `bun script/migration.ts` from packages/core.")
     }
   } finally {
@@ -170,6 +172,18 @@ function escapeTemplate(line: string) {
   return line.replaceAll("\\", "\\\\").replaceAll("`", "\\`").replaceAll("${", "\\${")
 }
 
+async function formatTypescript(input: string) {
+  const prettier = await import("prettier")
+  const typescript = await import("prettier/plugins/typescript")
+  const estree = await import("prettier/plugins/estree")
+  return prettier.format(input, {
+    parser: "typescript",
+    plugins: [typescript.default, estree.default],
+    semi: false,
+    printWidth: 120,
+  })
+}
+
 function renderRegistry(names: string[]) {
   return `import type { DatabaseMigration } from "./migration"
 

packages/core/src/catalog.ts

@@ -69,10 +69,10 @@ export const layer = Layer.effect(
     const policy = yield* Policy.Service
     const integrations = yield* Integration.Service
 
-    const available = (provider: ProviderV2.Info, integration: Integration.Info | undefined, connected: boolean) => {
+    const available = (provider: ProviderV2.Info, integration: Integration.Info | undefined) => {
       if (provider.disabled) return false
       if (typeof provider.request.body.apiKey === "string") return true
-      if (connected) return true
+      if (integration?.connections.length) return true
       return !integration
     }
 
@@ -183,13 +183,8 @@ export const layer = Layer.effect(
 
         available: Effect.fn("CatalogV2.provider.available")(function* () {
           const active = new Map((yield* integrations.list()).map((integration) => [integration.id, integration]))
-          const connections = yield* integrations.connection.list()
           return (yield* result.provider.all()).filter((provider) =>
-            available(
-              provider,
-              active.get(Integration.ID.make(provider.id)),
-              connections.has(Integration.ID.make(provider.id)),
-            ),
+            available(provider, active.get(Integration.ID.make(provider.id))),
           )
         }),
       },

packages/core/src/credential.ts

@@ -29,33 +29,33 @@ export class Key extends Schema.Class<Key>("Credential.Key")({
   metadata: Schema.optional(Schema.Record(Schema.String, Schema.String)),
 }) {}
 
-export const Info = Schema.Union([OAuth, Key])
+export const Value = Schema.Union([OAuth, Key])
   .pipe(Schema.toTaggedUnion("type"))
-  .annotate({ identifier: "Credential.Info" })
-export type Info = Schema.Schema.Type<typeof Info>
+  .annotate({ identifier: "Credential.Value" })
+export type Value = Schema.Schema.Type<typeof Value>
 
-export class Stored extends Schema.Class<Stored>("Credential.Stored")({
+export class Info extends Schema.Class<Info>("Credential.Info")({
   id: ID,
   integrationID: IntegrationSchema.ID,
   label: Schema.String,
-  value: Info,
+  value: Value,
 }) {}
 
 export interface Interface {
   /** Returns every stored credential. */
-  readonly all: () => Effect.Effect<Stored[]>
+  readonly all: () => Effect.Effect<Info[]>
   /** Returns stored credentials belonging to one integration. */
-  readonly list: (integrationID: IntegrationSchema.ID) => Effect.Effect<Stored[]>
+  readonly list: (integrationID: IntegrationSchema.ID) => Effect.Effect<Info[]>
   /** Returns one stored credential by ID. */
-  readonly get: (id: ID) => Effect.Effect<Stored | undefined>
+  readonly get: (id: ID) => Effect.Effect<Info | undefined>
   /** Replaces any credential for an integration and returns the new record. */
   readonly create: (input: {
     readonly integrationID: IntegrationSchema.ID
-    readonly value: Info
+    readonly value: Value
     readonly label?: string
-  }) => Effect.Effect<Stored>
+  }) => Effect.Effect<Info>
   /** Updates the label or secret value of a stored credential. */
-  readonly update: (id: ID, updates: Partial<Pick<Stored, "label" | "value">>) => Effect.Effect<void>
+  readonly update: (id: ID, updates: Partial<Pick<Info, "label" | "value">>) => Effect.Effect<void>
   /** Removes a stored credential. */
   readonly remove: (id: ID) => Effect.Effect<void>
 }
@@ -66,10 +66,10 @@ export const layer = Layer.effect(
   Service,
   Effect.gen(function* () {
     const { db } = yield* Database.Service
-    const decode = Schema.decodeUnknownSync(Info)
+    const decode = Schema.decodeUnknownSync(Value)
     const stored = (row: typeof CredentialTable.$inferSelect) => {
       if (!row.integration_id) return
-      return new Stored({
+      return new Info({
         id: row.id,
         integrationID: row.integration_id,
         label: row.label,
@@ -106,7 +106,7 @@ export const layer = Layer.effect(
         return row ? stored(row) : undefined
       }),
       create: Effect.fn("Credential.create")(function* (input) {
-        const credential = new Stored({
+        const credential = new Info({
           id: ID.create(),
           integrationID: input.integrationID,
           label: input.label ?? "default",

packages/core/src/credential/sql.ts

@@ -7,7 +7,7 @@ export const CredentialTable = sqliteTable("credential", {
   id: text().$type<Credential.ID>().primaryKey(),
   integration_id: text().$type<IntegrationSchema.ID>(),
   label: text().notNull(),
-  value: text({ mode: "json" }).$type<Credential.Info>().notNull(),
+  value: text({ mode: "json" }).$type<Credential.Value>().notNull(),
   connector_id: text(),
   method_id: text(),
   active: integer({ mode: "boolean" }),

packages/core/src/database/migration.gen.ts

@@ -37,5 +37,6 @@ export const migrations = (
     import("./migration/20260611035744_credential"),
     import("./migration/20260611192811_lush_chimera"),
     import("./migration/20260612174303_project_dir_strategy"),
+    import("./migration/20260622142730_simplify_session_context_epoch"),
   ])
 ).map((module) => module.default) satisfies DatabaseMigration.Migration[]

packages/core/src/database/migration/20260622142730_simplify_session_context_epoch.ts

@@ -0,0 +1,13 @@
+import { Effect } from "effect"
+import type { DatabaseMigration } from "../migration"
+
+export default {
+  id: "20260622142730_simplify_session_context_epoch",
+  up(tx) {
+    return Effect.gen(function* () {
+      yield* tx.run(`ALTER TABLE \`session_context_epoch\` DROP COLUMN \`agent\`;`)
+      yield* tx.run(`ALTER TABLE \`session_context_epoch\` DROP COLUMN \`replacement_seq\`;`)
+      yield* tx.run(`ALTER TABLE \`session_context_epoch\` DROP COLUMN \`revision\`;`)
+    })
+  },
+} satisfies DatabaseMigration.Migration

packages/core/src/database/schema.gen.ts

@@ -149,11 +149,8 @@ export default {
         CREATE TABLE \`session_context_epoch\` (
           \`session_id\` text PRIMARY KEY,
           \`baseline\` text NOT NULL,
-          \`agent\` text DEFAULT 'build' NOT NULL,
           \`snapshot\` text NOT NULL,
           \`baseline_seq\` integer NOT NULL,
-          \`replacement_seq\` integer,
-          \`revision\` integer DEFAULT 0 NOT NULL,
           CONSTRAINT \`fk_session_context_epoch_session_id_session_id_fk\` FOREIGN KEY (\`session_id\`) REFERENCES \`session\`(\`id\`) ON DELETE CASCADE
         );
       `)

packages/core/src/filesystem.ts

@@ -7,8 +7,8 @@ import { FSUtil } from "./fs-util"
 import { Location } from "./location"
 import { PositiveInt, RelativePath } from "./schema"
 import { FileSystemSearch } from "./filesystem/search"
-import { Entry, Match, PathError } from "./filesystem/schema"
-export { Entry, Match, PathError, Submatch } from "./filesystem/schema"
+import { Entry, Match } from "./filesystem/schema"
+export { Entry, Match, Submatch } from "./filesystem/schema"
 
 export const ReadInput = Schema.Struct({
   path: RelativePath,
@@ -58,10 +58,8 @@ export const Event = {
 }
 
 export interface Interface {
-  readonly read: (
-    input: ReadInput,
-  ) => Effect.Effect<{ readonly content: Uint8Array; readonly mime: string }, PathError | FSUtil.Error>
-  readonly list: (input?: ListInput) => Effect.Effect<Entry[], PathError | FSUtil.Error>
+  readonly read: (input: ReadInput) => Effect.Effect<{ readonly content: Uint8Array; readonly mime: string }>
+  readonly list: (input?: ListInput) => Effect.Effect<Entry[]>
   readonly find: (input: FindInput) => Effect.Effect<Entry[]>
   readonly glob: (input: GlobInput) => Effect.Effect<readonly Entry[]>
   readonly grep: (input: GrepInput) => Effect.Effect<readonly Match[]>
@@ -79,9 +77,9 @@ const baseLayer = Layer.effect(
     const resolve = Effect.fnUntraced(function* (input?: RelativePath) {
       const absolute = path.resolve(location.directory, input ?? ".")
       if (!FSUtil.contains(location.directory, absolute))
-        return yield* new PathError({ path: input ?? ".", reason: "lexical_escape" })
-      const real = yield* fs.realPath(absolute)
-      if (!FSUtil.contains(root, real)) return yield* new PathError({ path: input ?? ".", reason: "symlink_escape" })
+        return yield* Effect.die(new Error("Path escapes the location"))
+      const real = yield* fs.realPath(absolute).pipe(Effect.orDie)
+      if (!FSUtil.contains(root, real)) return yield* Effect.die(new Error("Path escapes the location"))
       return { absolute, real, directory: location.directory, root }
     })
     return Service.of({
@@ -90,18 +88,19 @@ const baseLayer = Layer.effect(
       grep: search.grep,
       read: Effect.fn("FileSystem.read")(function* (input) {
         const target = yield* resolve(input.path)
-        const info = yield* fs.stat(target.real)
-        if (info.type !== "File") return yield* new PathError({ path: input.path, reason: "not_file" })
+        const info = yield* fs.stat(target.real).pipe(Effect.orDie)
+        if (info.type !== "File") return yield* Effect.die(new Error("Path is not a file"))
         return {
-          content: yield* fs.readFile(target.real),
+          content: yield* fs.readFile(target.real).pipe(Effect.orDie),
           mime: FSUtil.mimeType(target.real),
         }
       }),
       list: Effect.fn("FileSystem.list")(function* (input = {}) {
         const target = yield* resolve(input.path)
-        const info = yield* fs.stat(target.real)
-        if (info.type !== "Directory") return yield* new PathError({ path: input.path ?? ".", reason: "not_directory" })
+        const info = yield* fs.stat(target.real).pipe(Effect.orDie)
+        if (info.type !== "Directory") return yield* Effect.die(new Error("Path is not a directory"))
         return yield* fs.readDirectoryEntries(target.real).pipe(
+          Effect.orDie,
           Effect.map((items) =>
             items
               .flatMap((item) => {
@@ -124,6 +123,6 @@ const baseLayer = Layer.effect(
   }),
 )
 
-export const layer = baseLayer.pipe(Layer.provide(FileSystemSearch.defaultLayer), Layer.provide(FSUtil.defaultLayer))
+export const layer = baseLayer.pipe(Layer.provide(FileSystemSearch.locationLayer), Layer.provide(FSUtil.defaultLayer))
 
 export const locationLayer = layer

packages/core/src/filesystem/schema.ts

@@ -21,8 +21,3 @@ export class Match extends Schema.Class<Match>("FileSystem.Match")({
   text: Schema.String,
   submatches: Schema.Array(Submatch),
 }) {}
-
-export class PathError extends Schema.TaggedErrorClass<PathError>()("FileSystem.PathError", {
-  path: Schema.String,
-  reason: Schema.Literals(["lexical_escape", "symlink_escape", "not_file", "not_directory"]),
-}) {}

packages/core/src/filesystem/search.ts

@@ -232,6 +232,6 @@ export const fffLayer = Layer.effect(
   }),
 )
 
-export const defaultLayer = Layer.unwrap(
+export const locationLayer = Layer.unwrap(
   Effect.sync(() => (Flag.OPENCODE_DISABLE_FFF || !Fff.available() ? ripgrepLayer : fffLayer)),
 )

packages/core/src/integration.ts

@@ -108,11 +108,11 @@ export type OAuthAuthorization = {
 } & (
   | {
       readonly mode: "auto"
-      readonly callback: Effect.Effect<Credential.Info, unknown>
+      readonly callback: Effect.Effect<Credential.Value, unknown>
     }
   | {
       readonly mode: "code"
-      readonly callback: (code: string) => Effect.Effect<Credential.Info, unknown>
+      readonly callback: (code: string) => Effect.Effect<Credential.Value, unknown>
     }
 )
 
@@ -214,8 +214,6 @@ export interface Interface extends State.Transformable<Draft> {
   /** Returns all integrations with their methods and current connections. */
   readonly list: () => Effect.Effect<Info[]>
   readonly connection: {
-    /** Returns active connections for every registered or credential-backed integration. */
-    readonly list: () => Effect.Effect<Map<ID, IntegrationConnection.Info>>
     /** Returns the active connection for one integration. */
     readonly forIntegration: (id: ID) => Effect.Effect<IntegrationConnection.Info | undefined>
     /** Runs a key method and stores the resulting credential. */
@@ -241,7 +239,7 @@ export interface Interface extends State.Transformable<Draft> {
     /** Updates a stored credential exposed as a connection. */
     readonly update: (
       credentialID: Credential.ID,
-      updates: Partial<Pick<Credential.Stored, "label">>,
+      updates: Partial<Pick<Credential.Info, "label">>,
     ) => Effect.Effect<void>
     /** Removes a stored credential connection. */
     readonly remove: (credentialID: Credential.ID) => Effect.Effect<void>
@@ -353,39 +351,27 @@ export const locationLayer = Layer.effect(
       finalize: () => events.publish(Event.Updated, {}).pipe(Effect.asVoid),
     })
 
-    const connections = (entry: Entry, saved: readonly Credential.Stored[]): IntegrationConnection.Info[] => {
-      const connected = saved.map((credential) => ({
-        type: "credential" as const,
-        id: credential.id,
-        label: credential.label,
-      }))
-      const detected = entry.methods
+    const resolveConnections = (entry: Entry | undefined, saved: readonly Credential.Info[]) => {
+      const credentials = saved
+        .map((credential) => ({
+          type: "credential" as const,
+          id: credential.id,
+          label: credential.label,
+        }))
+        .toReversed()
+      const env = (entry?.methods ?? [])
         .filter((method) => method.type === "env")
         .flatMap((method) => method.names.filter((name) => process.env[name]))
         .map((name) => ({ type: "env" as const, name }))
-      return [...connected, ...detected]
+      return [...credentials, ...env]
     }
 
-    const activeConnection = (
-      entry: Entry | undefined,
-      saved: readonly Credential.Stored[],
-    ): IntegrationConnection.Info | undefined => {
-      const credential = saved.at(-1)
-      if (credential) return { type: "credential", id: credential.id, label: credential.label }
-      if (!entry) return
-      const name = entry.methods
-        .filter((method) => method.type === "env")
-        .flatMap((method) => method.names)
-        .find((name) => process.env[name])
-      if (name) return { type: "env", name }
-    }
-
-    const project = (entry: Entry, saved: readonly Credential.Stored[]) =>
+    const project = (entry: Entry, connections: IntegrationConnection.Info[]) =>
       new Info({
         id: entry.ref.id,
         name: entry.ref.name,
         methods: entry.methods,
-        connections: connections(entry, saved),
+        connections,
       })
 
     const authorize = <A, E, R>(effect: Effect.Effect<A, E, R>) =>
@@ -399,7 +385,7 @@ export const locationLayer = Layer.effect(
       return error instanceof Error ? error.message : String(error)
     }
 
-    const settle = Effect.fnUntraced(function* (attemptID: AttemptID, exit: Exit.Exit<Credential.Info, unknown>) {
+    const settle = Effect.fnUntraced(function* (attemptID: AttemptID, exit: Exit.Exit<Credential.Value, unknown>) {
       const now = yield* Clock.currentTimeMillis
       const result = yield* SynchronizedRef.modify(attempts, (current) => {
         const attempt = current.get(attemptID)
@@ -450,28 +436,18 @@ export const locationLayer = Layer.effect(
       get: Effect.fn("Integration.get")(function* (id) {
         const entry = state.get().integrations.get(id)
         if (!entry) return undefined
-        return project(entry, yield* credentials.list(id))
+        return project(entry, resolveConnections(entry, yield* credentials.list(id)))
       }),
       list: Effect.fn("Integration.list")(function* () {
-        return (yield* Effect.forEach(state.get().integrations.values(), (entry) =>
-          Effect.gen(function* () {
-            return project(entry, yield* credentials.list(entry.ref.id))
-          }),
-        )).toSorted((a, b) => a.name.localeCompare(b.name))
+        const saved = Map.groupBy(yield* credentials.all(), (credential) => credential.integrationID)
+        return Array.from(state.get().integrations.values(), (entry) =>
+          project(entry, resolveConnections(entry, saved.get(entry.ref.id) ?? [])),
+        ).toSorted((a, b) => a.name.localeCompare(b.name))
       }),
       connection: {
-        list: Effect.fn("Integration.connection.list")(function* () {
-          const saved = Map.groupBy(yield* credentials.all(), (credential) => credential.integrationID)
-          return new Map(
-            new Set([...state.get().integrations.keys(), ...saved.keys()]).values().flatMap((id) => {
-              const connection = activeConnection(state.get().integrations.get(id), saved.get(id) ?? [])
-              return connection ? [[id, connection] as const] : []
-            }),
-          )
-        }),
         forIntegration: Effect.fn("Integration.connection.forIntegration")(function* (id) {
           const entry = state.get().integrations.get(id)
-          return activeConnection(entry, yield* credentials.list(id))
+          return resolveConnections(entry, yield* credentials.list(id))[0]
         }),
         key: Effect.fn("Integration.connection.key")(function* (input) {
           const method = state

packages/core/src/plugin.ts

@@ -103,8 +103,16 @@ export const layer = Layer.effect(
       }
     }[keyof Hooks][] = []
     const events = yield* EventV2.Service
-    const scope = yield* Scope.Scope
     const locks = KeyedMutex.makeUnsafe<ID>()
+    const scope = yield* Scope.make()
+
+    // One registry-owned scope lets shutdown remove every plugin transform in one batch.
+    yield* Effect.addFinalizer((exit) =>
+      Effect.gen(function* () {
+        hooks = []
+        yield* State.batch(Scope.close(scope, exit))
+      }),
+    )
 
     const svc = Service.of({
       add: Effect.fn("Plugin.add")(function* (input) {
@@ -112,7 +120,7 @@ export const layer = Layer.effect(
         yield* locks.withLock(id)(
           Effect.gen(function* () {
             const existing = hooks.find((item) => item.id === id)
-            if (existing) yield* Scope.close(existing.scope, Exit.void).pipe(Effect.ignore)
+            if (existing) yield* State.batch(Scope.close(existing.scope, Exit.void)).pipe(Effect.ignore)
             const childScope = yield* Scope.fork(scope)
             const result = yield* input.effect.pipe(
               Scope.provide(childScope),
@@ -181,7 +189,7 @@ export const layer = Layer.effect(
           Effect.gen(function* () {
             const existing = hooks.find((item) => item.id === id)
             hooks = hooks.filter((item) => item.id !== id)
-            if (existing) yield* Scope.close(existing.scope, Exit.void).pipe(Effect.ignore)
+            if (existing) yield* State.batch(Scope.close(existing.scope, Exit.void)).pipe(Effect.ignore)
           }),
         )
       }),

packages/core/src/public/opencode.ts

@@ -1,11 +1,9 @@
 export * as OpenCode from "./opencode"
 
 import { Context, Effect, Layer } from "effect"
-import { Catalog } from "../catalog"
 import { Database } from "../database/database"
 import { EventV2 } from "../event"
 import { LocationServiceMap } from "../location-layer"
-import { PluginBoot } from "../plugin/boot"
 import { ProjectV2 } from "../project"
 import { SessionV2 } from "../session"
 import * as SessionExecutionLocal from "../session/execution/local"
@@ -23,69 +21,22 @@ export interface Interface {
 /** Intentional public native API for Effect applications embedding OpenCode. */
 export class Service extends Context.Service<Service, Interface>()("@opencode/public/OpenCode") {}
 
-class SessionModelValidation extends Context.Service<
-  SessionModelValidation,
-  {
-    readonly validate: (
-      input: Session.SwitchModelInput & { readonly location: Session.Info["location"] },
-    ) => Effect.Effect<void, Session.ModelUnavailableError | Session.VariantUnavailableError>
-  }
->()("@opencode/public/OpenCode/SessionModelValidation") {}
-
-const ApplicationToolsLayer = ApplicationTools.layer
-const LocationServicesLayer = LocationServiceMap.layer.pipe(Layer.provide(ApplicationToolsLayer))
-const SessionModelValidationLayer = Layer.effect(
-  SessionModelValidation,
-  Effect.gen(function* () {
-    const locations = yield* LocationServiceMap
-    return SessionModelValidation.of({
-      validate: Effect.fn("OpenCode.sessions.validateModel")(function* (input) {
-        yield* Effect.gen(function* () {
-          yield* (yield* PluginBoot.Service).wait()
-          const catalog = yield* Catalog.Service
-          const model = (yield* catalog.model.available()).find(
-            (model) => model.providerID === input.model.providerID && model.id === input.model.id,
-          )
-          if (!model)
-            return yield* new Session.ModelUnavailableError({
-              providerID: input.model.providerID,
-              modelID: input.model.id,
-            })
-          if (
-            input.model.variant !== undefined &&
-            input.model.variant !== "default" &&
-            !model.variants.some((variant) => variant.id === input.model.variant)
-          )
-            return yield* new Session.VariantUnavailableError({
-              providerID: input.model.providerID,
-              modelID: input.model.id,
-              variant: input.model.variant,
-            })
-        }).pipe(Effect.provide(locations.get(input.location)))
-      }),
-    })
-  }),
+const SessionsLayer = SessionV2.layer.pipe(
+  Layer.provide(SessionProjector.layer),
+  Layer.provide(SessionExecutionLocal.layer),
+  Layer.provide(SessionStore.layer),
+  Layer.provide(EventV2.layer),
+  Layer.provide(Database.defaultLayer),
+  Layer.provide(ProjectV2.defaultLayer),
+  Layer.provide(LocationServiceMap.layer.pipe(Layer.provide(ApplicationTools.layer))),
+  Layer.orDie,
 )
-
-const SessionsLayer = Layer.merge(
-  SessionV2.layer.pipe(
-    Layer.provide(SessionProjector.layer),
-    Layer.provide(SessionExecutionLocal.layer),
-    Layer.provide(SessionStore.layer),
-    Layer.provide(EventV2.layer),
-    Layer.provide(Database.defaultLayer),
-    Layer.provide(ProjectV2.defaultLayer),
-    Layer.orDie,
-  ),
-  SessionModelValidationLayer,
-).pipe(Layer.provide(LocationServicesLayer))
 // TODO: Accept explicit storage so tests and embeddings can select disposable or application-owned persistence.
 export const layer = Layer.effect(
   Service,
   Effect.gen(function* () {
     const sessions = yield* SessionV2.Service
     const tools = yield* ApplicationTools.Service
-    const validation = yield* SessionModelValidation
     return Service.of({
       tools: { register: tools.register },
       sessions: {
@@ -98,11 +49,7 @@ export const layer = Layer.effect(
           }),
         get: sessions.get,
         list: sessions.list,
-        switchModel: Effect.fn("OpenCode.sessions.switchModel")(function* (input) {
-          const session = yield* sessions.get(input.sessionID)
-          yield* validation.validate({ ...input, location: session.location })
-          yield* sessions.switchModel(input)
-        }),
+        switchModel: sessions.switchModel,
         interrupt: sessions.interrupt,
         prompt: (input) =>
           sessions.prompt({
@@ -124,6 +71,6 @@ export const layer = Layer.effect(
       },
     })
   }),
-).pipe(Layer.provide(Layer.merge(ApplicationToolsLayer, SessionsLayer)))
+).pipe(Layer.provide(Layer.merge(ApplicationTools.layer, SessionsLayer)))
 
 // TODO: Add OpenCode.create(...) as the Promise facade over the same native API semantics.

packages/core/src/public/session.ts

@@ -1,7 +1,6 @@
 export * as Session from "./session"
 
-import { Effect, Schema, Stream } from "effect"
-import { ModelV2 } from "../model"
+import { Effect, Stream } from "effect"
 import { SessionV2 } from "../session"
 import { MessageDecodeError } from "../session/error"
 import { SessionEvent } from "../session/event"
@@ -41,23 +40,6 @@ export type NotFoundError = SessionV2.NotFoundError
 export const PromptConflictError = SessionV2.PromptConflictError
 export type PromptConflictError = SessionV2.PromptConflictError
 
-export class ModelUnavailableError extends Schema.TaggedErrorClass<ModelUnavailableError>()(
-  "Session.ModelUnavailableError",
-  {
-    providerID: Model.Ref.fields.providerID,
-    modelID: Model.Ref.fields.id,
-  },
-) {}
-
-export class VariantUnavailableError extends Schema.TaggedErrorClass<VariantUnavailableError>()(
-  "Session.VariantUnavailableError",
-  {
-    providerID: Model.Ref.fields.providerID,
-    modelID: Model.Ref.fields.id,
-    variant: ModelV2.VariantID,
-  },
-) {}
-
 export { MessageDecodeError }
 
 export interface CreateInput {
@@ -104,9 +86,7 @@ export interface Interface {
   readonly get: (sessionID: ID) => Effect.Effect<Info, NotFoundError>
   readonly list: (input?: ListInput) => Effect.Effect<Info[]>
   readonly prompt: (input: PromptInput) => Effect.Effect<Admission, NotFoundError | PromptConflictError>
-  readonly switchModel: (
-    input: SwitchModelInput,
-  ) => Effect.Effect<void, NotFoundError | ModelUnavailableError | VariantUnavailableError>
+  readonly switchModel: (input: SwitchModelInput) => Effect.Effect<void, NotFoundError>
   /** Interrupt the active V2 execution chain for one Session on this process. Interrupting an idle or missing Session is a no-op. */
   readonly interrupt: (sessionID: ID) => Effect.Effect<void>
   readonly messages: (input: MessagesInput) => Effect.Effect<Message[], NotFoundError | MessageDecodeError>

packages/core/src/session.ts

@@ -1,8 +1,8 @@
 export * as SessionV2 from "./session"
 export * from "./session/schema"
 
-import { Cause, DateTime, Effect, Layer, Schema, Context, Stream } from "effect"
-import { and, asc, desc, eq, gt, like, lt, or, type SQL } from "drizzle-orm"
+import { DateTime, Effect, Layer, Schema, Context, Stream } from "effect"
+import { and, asc, desc, eq, gt, gte, like, lt, or, type SQL } from "drizzle-orm"
 import { ProjectV2 } from "./project"
 import { WorkspaceV2 } from "./workspace"
 import { ModelV2 } from "./model"
@@ -25,7 +25,6 @@ import { fromRow } from "./session/info"
 import { SessionRunner } from "./session/runner/index"
 import { SessionStore } from "./session/store"
 import { SessionExecution } from "./session/execution"
-import { logFailure } from "./session/logging"
 import { MessageDecodeError } from "./session/error"
 import { SessionEvent } from "./session/event"
 import { SessionInput } from "./session/input"
@@ -126,10 +125,7 @@ export interface Interface {
     sessionID: SessionSchema.ID
     after?: number
   }) => Stream.Stream<SessionEvent.DurableEvent, NotFoundError>
-  readonly switchAgent: (input: {
-    sessionID: SessionSchema.ID
-    agent: string
-  }) => Effect.Effect<void, OperationUnavailableError>
+  readonly switchAgent: (input: { sessionID: SessionSchema.ID; agent: string }) => Effect.Effect<void, NotFoundError>
   readonly switchModel: (input: {
     sessionID: SessionSchema.ID
     model: ModelV2.Ref
@@ -171,20 +167,6 @@ export const layer = Layer.effect(
     const store = yield* SessionStore.Service
     const decodeMessage = Schema.decodeUnknownEffect(SessionMessage.Message)
     const isDurableSessionEvent = Schema.is(SessionEvent.Durable)
-    const scope = yield* Effect.scope
-
-    const enqueueWake = (admitted: SessionInput.Admitted) =>
-      execution.wake(admitted.sessionID, admitted.admittedSeq).pipe(
-        Effect.tapCause((cause) =>
-          Cause.hasInterruptsOnly(cause)
-            ? Effect.void
-            : logFailure("Failed to wake Session", admitted.sessionID, cause),
-        ),
-        Effect.ignore,
-        Effect.forkIn(scope, { startImmediately: true }),
-        Effect.asVoid,
-      )
-
     const decode = (row: typeof SessionMessageTable.$inferSelect) =>
       decodeMessage({ ...row.data, id: row.id, type: row.type }).pipe(
         Effect.mapError(
@@ -266,6 +248,13 @@ export const layer = Layer.effect(
         if ("directory" in input) conditions.push(eq(SessionTable.directory, input.directory))
         if (input.workspaceID) conditions.push(eq(SessionTable.workspace_id, input.workspaceID))
         if ("project" in input) conditions.push(eq(SessionTable.project_id, input.project))
+        if ("subpath" in input && input.subpath)
+          conditions.push(
+            or(
+              eq(SessionTable.path, input.subpath),
+              and(gte(SessionTable.path, `${input.subpath}/`), lt(SessionTable.path, `${input.subpath}0`)),
+            )!,
+          )
         if (input.search) conditions.push(like(SessionTable.title, `%${input.search}%`))
         if (input.anchor) {
           conditions.push(
@@ -345,10 +334,6 @@ export const layer = Layer.effect(
         Effect.uninterruptible(
           Effect.gen(function* () {
             yield* result.get(input.sessionID)
-            const returnPrompt = Effect.fnUntraced(function* (admitted: SessionInput.Admitted) {
-              if (input.resume !== false) yield* enqueueWake(admitted)
-              return admitted
-            }, Effect.uninterruptible)
             const messageID = input.id ?? SessionMessage.ID.create()
             const delivery = input.delivery ?? "steer"
             const expected = { sessionID: input.sessionID, messageID, prompt: input.prompt, delivery }
@@ -366,7 +351,8 @@ export const layer = Layer.effect(
             )
             if (!SessionInput.equivalent(admitted, expected))
               return yield* new PromptConflictError({ sessionID: input.sessionID, messageID })
-            return yield* returnPrompt(admitted)
+            if (input.resume !== false) yield* execution.wake(admitted.sessionID)
+            return admitted
           }),
         ),
       ),
@@ -376,8 +362,14 @@ export const layer = Layer.effect(
       skill: Effect.fn("V2Session.skill")(function* () {
         return yield* new OperationUnavailableError({ operation: "skill" })
       }),
-      switchAgent: Effect.fn("V2Session.switchAgent")(function* () {
-        return yield* new OperationUnavailableError({ operation: "switchAgent" })
+      switchAgent: Effect.fn("V2Session.switchAgent")(function* (input) {
+        yield* result.get(input.sessionID)
+        yield* events.publish(SessionEvent.AgentSwitched, {
+          sessionID: input.sessionID,
+          messageID: SessionMessage.ID.create(),
+          timestamp: yield* DateTime.now,
+          agent: input.agent,
+        })
       }),
       switchModel: Effect.fn("V2Session.switchModel")(function* (input) {
         yield* result.get(input.sessionID)
@@ -401,19 +393,7 @@ export const layer = Layer.effect(
         yield* execution.resume(sessionID)
       }),
       interrupt: Effect.fn("V2Session.interrupt")((sessionID) =>
-        Effect.uninterruptible(
-          Effect.gen(function* () {
-            const session = yield* store.get(sessionID)
-            if (!session) return yield* execution.interrupt(sessionID)
-            const event = yield* events.publish(SessionEvent.InterruptRequested, {
-              sessionID,
-              timestamp: yield* DateTime.now,
-            })
-            if (event.durable === undefined)
-              return yield* Effect.die("Interrupt request event is missing aggregate sequence")
-            yield* execution.interrupt(sessionID, event.durable.seq)
-          }),
-        ),
+        Effect.uninterruptible(execution.interrupt(sessionID)),
       ),
     })
 

packages/core/src/session/context-epoch.ts

@@ -1,54 +1,31 @@
 export * as SessionContextEpoch from "./context-epoch"
 
-import { and, eq, isNull, lt, or, sql } from "drizzle-orm"
+import { eq } from "drizzle-orm"
 import { DateTime, Effect, Schema } from "effect"
-import { AgentV2 } from "../agent"
 import type { Database } from "../database/database"
 import { EventV2 } from "../event"
-import { Location } from "../location"
 import { SystemContext } from "../system-context/index"
 import { ContextSnapshotDecodeError } from "./error"
 import { SessionEvent } from "./event"
+import { SessionHistory } from "./history"
 import { SessionInput } from "./input"
 import { SessionMessageID } from "./message-id"
 import { SessionSchema } from "./schema"
-import { SessionContextEpochTable, SessionTable } from "./sql"
+import { SessionContextEpochTable } from "./sql"
 
 type DatabaseService = Database.Interface["db"]
 
-class RevisionMismatch extends Error {}
-class LocationMismatch extends Error {}
-export class AgentMismatch extends Error {}
-export class AgentReplacementBlocked extends Schema.TaggedErrorClass<AgentReplacementBlocked>()(
-  "SessionContextEpoch.AgentReplacementBlocked",
-  { sessionID: SessionSchema.ID, previous: AgentV2.ID, current: AgentV2.ID },
-) {}
-
-const retryRevisionMismatch = <A, E>(attempt: () => Effect.Effect<A, E>): Effect.Effect<A, E> =>
-  attempt().pipe(
-    Effect.catchDefect((defect) =>
-      defect instanceof RevisionMismatch
-        ? Effect.yieldNow.pipe(Effect.andThen(retryRevisionMismatch(attempt)))
-        : Effect.die(defect),
-    ),
-  )
-
 interface Prepared {
   readonly baseline: string
   readonly baselineSeq: number
-  readonly revision: number
 }
 
 export function initialize(
   db: DatabaseService,
   context: Effect.Effect<SystemContext.SystemContext>,
   sessionID: SessionSchema.ID,
-  location: Location.Ref,
-  agent: AgentV2.ID,
 ): Effect.Effect<Prepared | undefined, SystemContext.InitializationBlocked> {
-  return retryRevisionMismatch(() => initializeOnce(db, context, sessionID, location, agent)).pipe(
-    Effect.withSpan("SessionContextEpoch.initialize"),
-  )
+  return initializeOnce(db, context, sessionID).pipe(Effect.withSpan("SessionContextEpoch.initialize"))
 }
 
 export function prepare(
@@ -56,12 +33,8 @@ export function prepare(
   events: EventV2.Interface,
   context: Effect.Effect<SystemContext.SystemContext>,
   sessionID: SessionSchema.ID,
-  location: Location.Ref,
-  agent: AgentV2.ID,
-): Effect.Effect<Prepared, SystemContext.InitializationBlocked | ContextSnapshotDecodeError | AgentReplacementBlocked> {
-  return retryRevisionMismatch(() => prepareOnce(db, events, context, sessionID, location, agent)).pipe(
-    Effect.withSpan("SessionContextEpoch.prepare"),
-  )
+): Effect.Effect<Prepared, SystemContext.InitializationBlocked | ContextSnapshotDecodeError> {
+  return prepareOnce(db, events, context, sessionID).pipe(Effect.withSpan("SessionContextEpoch.prepare"))
 }
 
 const prepareOnce = Effect.fnUntraced(function* (
@@ -69,57 +42,50 @@ const prepareOnce = Effect.fnUntraced(function* (
   events: EventV2.Interface,
   context: Effect.Effect<SystemContext.SystemContext>,
   sessionID: SessionSchema.ID,
-  location: Location.Ref,
-  agent: AgentV2.ID,
 ) {
-  const [value, stored] = yield* Effect.all([context, find(db, sessionID)], { concurrency: "unbounded" })
+  const [value, stored, compaction] = yield* Effect.all(
+    [context, find(db, sessionID), SessionHistory.latestCompaction(db, sessionID)],
+    { concurrency: "unbounded" },
+  )
   if (!stored) {
     const generation = yield* SystemContext.initialize(value)
-    const baselineSeq = yield* insert(db, sessionID, location, agent, generation)
-    return { baseline: generation.baseline, baselineSeq, revision: 0 }
+    const baselineSeq = yield* insert(db, sessionID, generation)
+    return { baseline: generation.baseline, baselineSeq }
   }
 
   const snapshot = yield* Schema.decodeUnknownEffect(SystemContext.Snapshot)(stored.snapshot).pipe(
     Effect.mapError((error) => new ContextSnapshotDecodeError({ sessionID, details: String(error) })),
   )
-  const replacingAgent = stored.agent !== agent
-  const result =
-    stored.replacement_seq === null && !replacingAgent
-      ? yield* SystemContext.reconcile(value, snapshot)
-      : yield* SystemContext.replace(value, snapshot)
-  if (result._tag === "ReplacementBlocked" && replacingAgent) {
-    yield* fence(db, sessionID, agent, stored.revision)
-    return yield* new AgentReplacementBlocked({ sessionID, previous: stored.agent, current: agent })
-  }
+  const replacementSeq = compaction !== undefined && compaction.seq > stored.baseline_seq ? compaction.seq : undefined
+  const result = replacementSeq
+    ? yield* SystemContext.replace(value, snapshot)
+    : yield* SystemContext.reconcile(value, snapshot)
   if (result._tag === "Unchanged" || result._tag === "ReplacementBlocked") {
-    yield* fence(db, sessionID, agent, stored.revision)
-    return { baseline: stored.baseline, baselineSeq: stored.baseline_seq, revision: stored.revision }
+    return { baseline: stored.baseline, baselineSeq: stored.baseline_seq }
   }
   if (result._tag === "ReplacementReady") {
-    const replacementSeq = stored.replacement_seq ?? (yield* SessionInput.latestSeq(db, sessionID))
-    yield* replace(db, sessionID, agent, stored.revision, replacementSeq, result.generation)
-    return { baseline: result.generation.baseline, baselineSeq: replacementSeq, revision: stored.revision + 1 }
+    const baselineSeq = replacementSeq ?? (yield* SessionInput.latestSeq(db, sessionID))
+    yield* replace(db, sessionID, baselineSeq, result.generation)
+    return { baseline: result.generation.baseline, baselineSeq }
   }
 
   yield* events.publish(
     SessionEvent.ContextUpdated,
     { sessionID, messageID: SessionMessageID.ID.create(), timestamp: yield* DateTime.now, text: result.text },
-    { commit: () => advance(db, sessionID, stored.revision, result.snapshot).pipe(Effect.orDie) },
+    { commit: () => advance(db, sessionID, result.snapshot).pipe(Effect.orDie) },
   )
-  return { baseline: stored.baseline, baselineSeq: stored.baseline_seq, revision: stored.revision + 1 }
+  return { baseline: stored.baseline, baselineSeq: stored.baseline_seq }
 })
 
 const initializeOnce = Effect.fnUntraced(function* (
   db: DatabaseService,
   context: Effect.Effect<SystemContext.SystemContext>,
   sessionID: SessionSchema.ID,
-  location: Location.Ref,
-  agent: AgentV2.ID,
 ) {
   if (yield* exists(db, sessionID)) return
   const generation = yield* context.pipe(Effect.flatMap(SystemContext.initialize))
-  const baselineSeq = yield* insert(db, sessionID, location, agent, generation)
-  return { baseline: generation.baseline, baselineSeq, revision: 0 }
+  const baselineSeq = yield* insert(db, sessionID, generation)
+  return { baseline: generation.baseline, baselineSeq }
 })
 
 const exists = Effect.fn("SessionContextEpoch.exists")(function* (db: DatabaseService, sessionID: SessionSchema.ID) {
@@ -142,39 +108,6 @@ const find = Effect.fn("SessionContextEpoch.find")(function* (db: DatabaseServic
     .pipe(Effect.orDie)
 })
 
-const requireAgentSelection = Effect.fnUntraced(function* (
-  db: DatabaseService,
-  sessionID: SessionSchema.ID,
-  agent: AgentV2.ID,
-) {
-  const selected = yield* db
-    .select({ agent: SessionTable.agent })
-    .from(SessionTable)
-    .where(eq(SessionTable.id, sessionID))
-    .get()
-    .pipe(Effect.orDie)
-  if (!selected || (selected.agent !== null && selected.agent !== agent)) return yield* Effect.die(new AgentMismatch())
-})
-
-export const requestReplacement = Effect.fn("SessionContextEpoch.requestReplacement")(function* (
-  db: DatabaseService,
-  sessionID: SessionSchema.ID,
-  seq: number,
-) {
-  return yield* db
-    .update(SessionContextEpochTable)
-    .set({ replacement_seq: seq, revision: sql`${SessionContextEpochTable.revision} + 1` })
-    .where(
-      and(
-        eq(SessionContextEpochTable.session_id, sessionID),
-        lt(SessionContextEpochTable.baseline_seq, seq),
-        or(isNull(SessionContextEpochTable.replacement_seq), lt(SessionContextEpochTable.replacement_seq, seq)),
-      ),
-    )
-    .run()
-    .pipe(Effect.orDie)
-})
-
 export const reset = Effect.fn("SessionContextEpoch.reset")(function* (
   db: DatabaseService,
   sessionID: SessionSchema.ID,
@@ -189,155 +122,53 @@ export const reset = Effect.fn("SessionContextEpoch.reset")(function* (
 const insert = Effect.fnUntraced(function* (
   db: DatabaseService,
   sessionID: SessionSchema.ID,
-  location: Location.Ref,
-  agent: AgentV2.ID,
   generation: SystemContext.Generation,
 ) {
-  return yield* db
-    .transaction(
-      () =>
-        Effect.gen(function* () {
-          const placed = yield* db
-            .select({ agent: SessionTable.agent })
-            .from(SessionTable)
-            .where(
-              and(
-                eq(SessionTable.id, sessionID),
-                eq(SessionTable.directory, location.directory),
-                location.workspaceID === undefined
-                  ? isNull(SessionTable.workspace_id)
-                  : eq(SessionTable.workspace_id, location.workspaceID),
-              ),
-            )
-            .get()
-            .pipe(Effect.orDie)
-          if (!placed) return yield* Effect.die(new LocationMismatch())
-          if (placed.agent !== null && placed.agent !== agent) return yield* Effect.die(new AgentMismatch())
-          const baselineSeq = yield* SessionInput.latestSeq(db, sessionID)
-          yield* db
-            .insert(SessionContextEpochTable)
-            .values({
-              session_id: sessionID,
-              baseline: generation.baseline,
-              agent,
-              snapshot: generation.snapshot,
-              baseline_seq: baselineSeq,
-              revision: 0,
-            })
-            .onConflictDoNothing()
-            .returning({ sessionID: SessionContextEpochTable.session_id })
-            .get()
-            .pipe(
-              Effect.orDie,
-              Effect.flatMap((inserted) => (inserted ? Effect.void : Effect.die(new RevisionMismatch()))),
-            )
-          return baselineSeq
-        }),
-      { behavior: "immediate" },
-    )
+  const baselineSeq = yield* SessionInput.latestSeq(db, sessionID)
+  yield* db
+    .insert(SessionContextEpochTable)
+    .values({
+      session_id: sessionID,
+      baseline: generation.baseline,
+      snapshot: generation.snapshot,
+      baseline_seq: baselineSeq,
+    })
+    .run()
     .pipe(Effect.orDie)
+  return baselineSeq
 })
 
 const replace = Effect.fnUntraced(function* (
   db: DatabaseService,
   sessionID: SessionSchema.ID,
-  agent: AgentV2.ID,
-  expectedRevision: number,
   baselineSeq: number,
   generation: SystemContext.Generation,
 ) {
-  yield* db
-    .transaction(
-      () =>
-        Effect.gen(function* () {
-          yield* requireAgentSelection(db, sessionID, agent)
-          const updated = yield* db
-            .update(SessionContextEpochTable)
-            .set({
-              baseline: generation.baseline,
-              agent,
-              snapshot: generation.snapshot,
-              baseline_seq: baselineSeq,
-              replacement_seq: null,
-              revision: expectedRevision + 1,
-            })
-            .where(
-              and(
-                eq(SessionContextEpochTable.session_id, sessionID),
-                eq(SessionContextEpochTable.revision, expectedRevision),
-              ),
-            )
-            .returning({ revision: SessionContextEpochTable.revision })
-            .get()
-            .pipe(Effect.orDie)
-          if (!updated) return yield* Effect.die(new RevisionMismatch())
-        }),
-      { behavior: "immediate" },
-    )
-    .pipe(Effect.orDie)
-})
-
-const fence = Effect.fnUntraced(function* (
-  db: DatabaseService,
-  sessionID: SessionSchema.ID,
-  agent: AgentV2.ID,
-  expectedRevision: number,
-) {
-  const current = yield* db
-    .select({ selected: SessionTable.agent, revision: SessionContextEpochTable.revision })
-    .from(SessionContextEpochTable)
-    .innerJoin(SessionTable, eq(SessionTable.id, SessionContextEpochTable.session_id))
-    .where(eq(SessionContextEpochTable.session_id, sessionID))
-    .get()
-    .pipe(Effect.orDie)
-  if (!current || (current.selected !== null && current.selected !== agent))
-    return yield* Effect.die(new AgentMismatch())
-  if (current.revision !== expectedRevision) return yield* Effect.die(new RevisionMismatch())
-})
-
-export const current = Effect.fn("SessionContextEpoch.current")(function* (
-  db: DatabaseService,
-  sessionID: SessionSchema.ID,
-  agent: AgentV2.ID,
-  revision: number,
-) {
-  const value = yield* db
-    .select({
-      agent: SessionContextEpochTable.agent,
-      selected: SessionTable.agent,
-      revision: SessionContextEpochTable.revision,
+  const updated = yield* db
+    .update(SessionContextEpochTable)
+    .set({
+      baseline: generation.baseline,
+      snapshot: generation.snapshot,
+      baseline_seq: baselineSeq,
     })
-    .from(SessionContextEpochTable)
-    .innerJoin(SessionTable, eq(SessionTable.id, SessionContextEpochTable.session_id))
     .where(eq(SessionContextEpochTable.session_id, sessionID))
+    .returning({ sessionID: SessionContextEpochTable.session_id })
     .get()
     .pipe(Effect.orDie)
-  return (
-    value !== undefined &&
-    value.agent === agent &&
-    (value.selected === null || value.selected === agent) &&
-    value.revision === revision
-  )
+  if (!updated) return yield* Effect.die("Context Epoch not found")
 })
 
 const advance = Effect.fnUntraced(function* (
   db: DatabaseService,
   sessionID: SessionSchema.ID,
-  expectedRevision: number,
   snapshot: SystemContext.Snapshot,
 ) {
   const updated = yield* db
     .update(SessionContextEpochTable)
-    .set({ snapshot, revision: expectedRevision + 1 })
-    .where(
-      and(
-        eq(SessionContextEpochTable.session_id, sessionID),
-        eq(SessionContextEpochTable.revision, expectedRevision),
-        isNull(SessionContextEpochTable.replacement_seq),
-      ),
-    )
-    .returning({ revision: SessionContextEpochTable.revision })
+    .set({ snapshot })
+    .where(eq(SessionContextEpochTable.session_id, sessionID))
+    .returning({ sessionID: SessionContextEpochTable.session_id })
     .get()
     .pipe(Effect.orDie)
-  if (!updated) return yield* Effect.die(new RevisionMismatch())
+  if (!updated) return yield* Effect.die("Context Epoch not found")
 })

packages/core/src/session/event.ts

@@ -118,13 +118,6 @@ export namespace PromptLifecycle {
   export type Promoted = typeof Promoted.Type
 }
 
-export const InterruptRequested = EventV2.define({
-  type: "session.next.interrupt.requested",
-  ...options,
-  schema: Base,
-})
-export type InterruptRequested = typeof InterruptRequested.Type
-
 export const ContextUpdated = EventV2.define({
   type: "session.next.context.updated",
   ...options,
@@ -475,7 +468,6 @@ const DurableDefinitions = [
   Prompted,
   PromptLifecycle.Admitted,
   PromptLifecycle.Promoted,
-  InterruptRequested,
   ContextUpdated,
   Synthetic,
   Shell.Started,

packages/core/src/session/execution.ts

@@ -5,12 +5,12 @@ import { SessionRunner } from "./runner/index"
 import { SessionSchema } from "./schema"
 
 export interface Interface {
-  /** Explicitly drain one Session, making at least one provider attempt. */
+  /** Starts execution while idle or joins the active execution. */
   readonly resume: (sessionID: SessionSchema.ID) => Effect.Effect<void, SessionRunner.RunError>
-  /** Schedule a drain after durable work is recorded. Repeated wakeups may coalesce. */
-  readonly wake: (sessionID: SessionSchema.ID, seq?: number) => Effect.Effect<void, SessionRunner.RunError>
+  /** Registers newly recorded work. Repeated wakeups may coalesce. */
+  readonly wake: (sessionID: SessionSchema.ID) => Effect.Effect<void>
   /** Interrupt active work owned by this process. Idle interruption is a no-op. */
-  readonly interrupt: (sessionID: SessionSchema.ID, seq?: number) => Effect.Effect<void>
+  readonly interrupt: (sessionID: SessionSchema.ID) => Effect.Effect<void>
 }
 
 /** Routes execution from a Session ID to the runner owned by that Session's Location. */

packages/core/src/session/execution/local.ts

@@ -1,11 +1,10 @@
-import { Effect, Layer } from "effect"
+import { Cause, Effect, Layer } from "effect"
 import { LocationServiceMap } from "../../location-layer"
 import { SessionRunCoordinator } from "../run-coordinator"
 import { SessionRunner } from "../runner"
 import { SessionSchema } from "../schema"
 import { SessionStore } from "../store"
 import { SessionExecution } from "../execution"
-import { logFailure } from "../logging"
 
 /** Current-process routing for implicit-local Locations. Future remote placement belongs here. */
 export const layer = Layer.effect(
@@ -13,15 +12,19 @@ export const layer = Layer.effect(
   Effect.gen(function* () {
     const store = yield* SessionStore.Service
     const locations = yield* LocationServiceMap
-    const coordinator = yield* SessionRunCoordinator.make<SessionSchema.ID, void, SessionRunner.RunError>({
-      drain: Effect.fnUntraced(function* (sessionID: SessionSchema.ID, mode) {
+    const coordinator = yield* SessionRunCoordinator.make<SessionSchema.ID, SessionRunner.RunError>({
+      drain: Effect.fnUntraced(function* (sessionID: SessionSchema.ID, force) {
         const session = yield* store.get(sessionID)
         if (!session) return yield* Effect.die(`Session not found: ${sessionID}`)
-        return yield* SessionRunner.Service.use((runner) => runner.run({ sessionID, force: mode === "run" })).pipe(
+        return yield* SessionRunner.Service.use((runner) => runner.run({ sessionID, force })).pipe(
           Effect.provide(locations.get(session.location)),
+          Effect.tapCause((cause) =>
+            Cause.hasInterruptsOnly(cause)
+              ? Effect.void
+              : Effect.logError("Failed to drain Session", cause).pipe(Effect.annotateLogs({ sessionID })),
+          ),
         )
       }),
-      onFailure: (sessionID, cause) => logFailure("Failed to drain Session", sessionID, cause),
     })
 
     return SessionExecution.Service.of({

packages/core/src/session/history.ts

@@ -10,9 +10,9 @@ type DatabaseService = Database.Interface["db"]
 
 const decode = Schema.decodeUnknownEffect(SessionMessage.Message)
 
-const latestCompaction = Effect.fnUntraced(function* (db: DatabaseService, sessionID: SessionSchema.ID) {
+export const latestCompaction = Effect.fnUntraced(function* (db: DatabaseService, sessionID: SessionSchema.ID) {
   return yield* db
-    .select()
+    .select({ seq: SessionMessageTable.seq })
     .from(SessionMessageTable)
     .where(and(eq(SessionMessageTable.session_id, sessionID), eq(SessionMessageTable.type, "compaction")))
     .orderBy(desc(SessionMessageTable.seq))

packages/core/src/session/logging.ts

@@ -1,8 +0,0 @@
-import { Cause, Effect } from "effect"
-import { SessionSchema } from "./schema"
-
-export const logFailure = (
-  message: "Failed to drain Session" | "Failed to wake Session",
-  sessionID: SessionSchema.ID,
-  cause: Cause.Cause<unknown>,
-) => Effect.logError(message, cause).pipe(Effect.annotateLogs({ sessionID }))

packages/core/src/session/message-updater.ts

@@ -138,7 +138,6 @@ export function update(adapter: Adapter, event: SessionEvent.Event) {
       },
       "session.next.prompt.admitted": () => Effect.void,
       "session.next.prompt.promoted": () => Effect.void,
-      "session.next.interrupt.requested": () => Effect.void,
       "session.next.context.updated": (event) =>
         adapter.appendMessage(
           new SessionMessage.System({

packages/core/src/session/projector.ts

@@ -329,19 +329,14 @@ export const layer = Layer.effectDiscard(
         if (next) yield* applyUsage(db, sessionID, next)
       }),
     )
-    yield* events.project(SessionEvent.AgentSwitched, (event) => {
-      if (event.durable === undefined) return Effect.die("Durable Session event is missing aggregate sequence")
-      return db
+    yield* events.project(SessionEvent.AgentSwitched, (event) =>
+      db
         .update(SessionTable)
         .set({ agent: event.data.agent, time_updated: DateTime.toEpochMillis(event.data.timestamp) })
         .where(eq(SessionTable.id, event.data.sessionID))
         .run()
-        .pipe(
-          Effect.orDie,
-          Effect.andThen(run(db, event)),
-          Effect.andThen(SessionContextEpoch.requestReplacement(db, event.data.sessionID, event.durable.seq)),
-        )
-    })
+        .pipe(Effect.orDie, Effect.andThen(run(db, event))),
+    )
     yield* events.project(SessionEvent.ModelSwitched, (event) =>
       Effect.gen(function* () {
         yield* db
@@ -351,8 +346,6 @@ export const layer = Layer.effectDiscard(
           .run()
           .pipe(Effect.orDie)
         yield* run(db, event)
-        if (event.durable === undefined) return yield* Effect.die("Durable Session event is missing aggregate sequence")
-        yield* SessionContextEpoch.requestReplacement(db, event.data.sessionID, event.durable.seq)
       }),
     )
     yield* events.project(SessionEvent.Prompted, (event) =>
@@ -406,8 +399,6 @@ export const layer = Layer.effectDiscard(
         )
       }),
     )
-    yield* events.project(SessionEvent.InterruptRequested, () => Effect.void)
-    // TODO: Reconstruct context epoch replacement state during replay without adding replay state to every EventV2 payload.
     yield* events.project(SessionEvent.ContextUpdated, (event) => run(db, event))
     yield* events.project(SessionEvent.Synthetic, (event) => run(db, event))
     yield* events.project(SessionEvent.Shell.Started, (event) => run(db, event))
@@ -426,15 +417,9 @@ export const layer = Layer.effectDiscard(
     yield* events.project(SessionEvent.Reasoning.Started, (event) => run(db, event))
     yield* events.project(SessionEvent.Reasoning.Ended, (event) => run(db, event))
     // yield* events.project(SessionEvent.Retried, (event) => run(db, event))
-    yield* events.project(SessionEvent.Compaction.Ended, (event) => {
-      if (event.durable === undefined) return Effect.die("Durable Session event is missing aggregate sequence")
-      if (event.durable.version === 1) return Effect.void
-      const seq = event.durable.seq
-      return Effect.gen(function* () {
-        yield* run(db, event)
-        yield* SessionContextEpoch.requestReplacement(db, event.data.sessionID, seq)
-      })
-    })
+    yield* events.project(SessionEvent.Compaction.Ended, (event) =>
+      event.durable?.version === 1 ? Effect.void : run(db, event),
+    )
   }),
 )
 

packages/core/src/session/run-coordinator.ts

@@ -1,106 +1,43 @@
 export * as SessionRunCoordinator from "./run-coordinator"
 
-import { Cause, Context, Deferred, Effect, Exit, Fiber, FiberSet, Layer, Scope } from "effect"
-import { SessionRunner } from "./runner"
-import { logFailure } from "./logging"
-import { SessionSchema } from "./schema"
+import { Deferred, Effect, Exit, Fiber, FiberSet, Scope } from "effect"
 
-export type Mode = "run" | "wake"
-
-/** Why one drain generation should run. Explicit runs dominate advisory wakes when demands coalesce. */
-type Demand = { readonly _tag: "run" } | { readonly _tag: "wake"; readonly seq?: number }
-
-/**
- * Runs at most one drain chain per key while allowing different keys to drain concurrently.
- *
- * For each key:
- *
- *   idle --run/wake--> draining --run/wake--> draining + one coalesced rerun --> idle
- *
- * `run` is an explicit drain request. It starts a chain or joins the current chain and
- * upgrades a pending follow-up so the caller receives explicit-run semantics.
- *
- * `wake` reports that durable work may now be available. It starts a chain while idle or
- * requests one coalesced follow-up while draining. Repeated wakes collapse together.
- *
- * `interrupt` stops the current ownership chain. Advisory wakes from before the interrupt
- * boundary are suppressed; advisory wakes after the boundary run after cleanup.
- */
-export interface Coordinator<Key, A, E> {
-  /** Starts or joins one explicit drain generation. */
-  readonly run: (key: Key) => Effect.Effect<A, E>
-  /** Coalesces one wake-up after durable work is recorded. */
-  readonly wake: (key: Key, seq?: number) => Effect.Effect<void>
-  /** Waits until the current ownership chain settles. */
-  readonly awaitIdle: (key: Key) => Effect.Effect<void, E>
-  /** Interrupts the active ownership chain without automatically draining pending wakes. */
-  readonly interrupt: (key: Key, seq?: number) => Effect.Effect<void>
+/** Serializes execution for each key while allowing different keys to run concurrently. */
+export interface Coordinator<Key, E> {
+  /** Starts execution while idle or joins the active execution. */
+  readonly run: (key: Key) => Effect.Effect<void, E>
+  /** Registers one coalesced follow-up after newly recorded work. */
+  readonly wake: (key: Key) => Effect.Effect<void>
+  /** Stops active execution and waits for its cleanup. */
+  readonly interrupt: (key: Key) => Effect.Effect<void>
 }
 
-/** One Session's process-local execution lane: one active demand and at most one coalesced follow-up. */
-type Entry<A, E> = {
-  readonly done: Deferred.Deferred<A, E>
-  readonly settled: Deferred.Deferred<Exit.Exit<A, E>>
-  current: Demand
-  pending?: Demand
-  explicitWaiter?: Deferred.Deferred<A, E>
-  interruptSeq?: number
+type Entry<E> = {
+  readonly done: Deferred.Deferred<void, E>
   owner?: Fiber.Fiber<void, never>
+  pendingWake: boolean
   stopping: boolean
 }
 
-/** Combines follow-up demand: runs dominate, while wakes retain the newest durable admission sequence. */
-const coalesce = (left: Demand | undefined, right: Demand): Demand => {
-  if (left?._tag === "run" || right._tag === "run") return { _tag: "run" }
-  return { _tag: "wake", seq: maxSeq(left?.seq, right.seq) }
-}
-
-const maxSeq = (left: number | undefined, right: number | undefined) => {
-  if (left === undefined) return right
-  if (right === undefined) return left
-  return Math.max(left, right)
-}
-
-/** Constructs a scoped coordinator. Every in-memory transition is synchronous. */
-export const make = <Key, A, E>(options: {
-  readonly drain: (key: Key, mode: Mode) => Effect.Effect<A, E>
-  readonly onFailure?: (key: Key, cause: Cause.Cause<E>) => Effect.Effect<void>
-}): Effect.Effect<Coordinator<Key, A, E>, never, Scope.Scope> =>
+export const make = <Key, E>(options: {
+  readonly drain: (key: Key, force: boolean) => Effect.Effect<void, E>
+}): Effect.Effect<Coordinator<Key, E>, never, Scope.Scope> =>
   Effect.gen(function* () {
-    const active = new Map<Key, Entry<A, E>>()
-    const interruptSeq = new Map<Key, number>()
-    const report = yield* FiberSet.makeRuntime<never, void, never>()
+    const active = new Map<Key, Entry<E>>()
     const fork = yield* FiberSet.makeRuntime<never, void, never>()
-    const shutdown = Deferred.makeUnsafe<void>()
-    let closed = false
-    yield* Effect.addFinalizer(() =>
-      Effect.sync(() => {
-        closed = true
-        Deferred.doneUnsafe(shutdown, Effect.void)
-        active.clear()
-        interruptSeq.clear()
-      }),
-    )
 
-    const makeEntry = (current: Demand, explicitWaiter?: Deferred.Deferred<A, E>): Entry<A, E> => ({
-      done: Deferred.makeUnsafe<A, E>(),
-      settled: Deferred.makeUnsafe<Exit.Exit<A, E>>(),
-      current,
-      explicitWaiter,
+    const makeEntry = (): Entry<E> => ({
+      done: Deferred.makeUnsafe<void, E>(),
+      pendingWake: false,
       stopping: false,
     })
 
-    const start = (key: Key, entry: Entry<A, E>, demand: Demand, successor = false) => {
+    const start = (key: Key, entry: Entry<E>, force: boolean, successor = false) => {
       const ready = Deferred.makeUnsafe<void>()
-      const drain = Effect.suspend(() => options.drain(key, demand._tag))
-      // Initial work retains immediate-start behavior but cannot run before ownership is published.
-      // Observer-started successors yield once so synchronous drains cannot recurse on the JS stack.
       const owner = fork(
-        (successor
-          ? Effect.yieldNow.pipe(Effect.andThen(drain))
-          : Deferred.await(ready).pipe(Effect.andThen(drain))
-        ).pipe(
-          Effect.onExit((exit) => Effect.sync(() => settle(key, entry, demand, exit))),
+        (successor ? Effect.yieldNow : Deferred.await(ready)).pipe(
+          Effect.andThen(Effect.suspend(() => options.drain(key, force))),
+          Effect.onExit((exit) => Effect.sync(() => settle(key, entry, exit))),
           Effect.exit,
           Effect.asVoid,
         ),
@@ -109,176 +46,57 @@ export const make = <Key, A, E>(options: {
       if (!successor) Deferred.doneUnsafe(ready, Effect.void)
     }
 
-    const settle = (key: Key, entry: Entry<A, E>, demand: Demand, exit: Exit.Exit<A, E>) => {
-      if (closed) {
-        Deferred.doneUnsafe(entry.done, exit)
-        Deferred.doneUnsafe(entry.settled, Effect.succeed(exit))
-        return
-      }
-      if (demand._tag === "run" && entry.explicitWaiter !== undefined) {
-        Deferred.doneUnsafe(entry.explicitWaiter, exit)
-        entry.explicitWaiter = undefined
-      }
-      if (entry.stopping && demand._tag === "wake" && entry.explicitWaiter !== undefined) {
-        Deferred.doneUnsafe(entry.explicitWaiter, exit)
-        entry.explicitWaiter = undefined
-      }
-      if (active.get(key) !== entry) {
-        Deferred.doneUnsafe(entry.done, exit)
-        Deferred.doneUnsafe(entry.settled, Effect.succeed(exit))
-        return
-      }
-      if (exit._tag === "Success" && !entry.stopping) {
-        if (entry.pending !== undefined) {
-          const pending = entry.pending
-          entry.pending = undefined
-          entry.current = pending
-          start(key, entry, pending, true)
-          return
-        }
-        active.delete(key)
-        Deferred.doneUnsafe(entry.done, exit)
-        Deferred.doneUnsafe(entry.settled, Effect.succeed(exit))
+    const settle = (key: Key, entry: Entry<E>, exit: Exit.Exit<void, E>) => {
+      if (Exit.isSuccess(exit) && !entry.stopping && entry.pendingWake) {
+        entry.pendingWake = false
+        start(key, entry, false, true)
         return
       }
 
-      const successor = entry.pending !== undefined ? makeEntry(entry.pending, entry.explicitWaiter) : undefined
+      const successor = entry.pendingWake ? makeEntry() : undefined
       if (successor === undefined) active.delete(key)
-      else active.set(key, successor)
-      if (successor !== undefined) start(key, successor, successor.current, true)
-      Deferred.doneUnsafe(entry.done, exit)
-      Deferred.doneUnsafe(entry.settled, Effect.succeed(exit))
-      if (
-        exit._tag === "Failure" &&
-        !(entry.stopping && Cause.hasInterruptsOnly(exit.cause)) &&
-        demand._tag === "wake" &&
-        options.onFailure !== undefined
-      ) {
-        report(Effect.suspend(() => options.onFailure!(key, exit.cause)))
+      else {
+        active.set(key, successor)
+        start(key, successor, false, true)
       }
+      Deferred.doneUnsafe(entry.done, exit)
     }
 
-    const wake = (key: Key, seq?: number) =>
-      Effect.sync(() => {
-        if (closed) return
-        if (!isAfterInterrupt(key, seq)) return
+    const run = (key: Key): Effect.Effect<void, E> =>
+      Effect.uninterruptibleMask((restore) => {
         const entry = active.get(key)
         if (entry !== undefined) {
-          if (!acceptsWake(entry, seq)) return
-          entry.pending = coalesce(entry.pending, { _tag: "wake", seq })
+          if (entry.stopping) return restore(Deferred.await(entry.done).pipe(Effect.andThen(run(key))))
+          return restore(Deferred.await(entry.done))
+        }
+
+        const next = makeEntry()
+        active.set(key, next)
+        start(key, next, true)
+        return restore(Deferred.await(next.done))
+      })
+
+    const wake = (key: Key) =>
+      Effect.sync(() => {
+        const entry = active.get(key)
+        if (entry !== undefined) {
+          entry.pendingWake = true
           return
         }
 
-        const next = makeEntry({ _tag: "wake", seq })
+        const next = makeEntry()
         active.set(key, next)
-        start(key, next, next.current)
+        start(key, next, false)
       })
 
-    const awaitIdle = (key: Key): Effect.Effect<void, E> =>
-      Effect.gen(function* () {
-        let firstFailure: Cause.Cause<E> | undefined
-        while (!closed) {
-          const entry = active.get(key)
-          if (entry === undefined) break
-          const exit = yield* Effect.raceFirst(
-            Deferred.await(entry.settled),
-            Deferred.await(shutdown).pipe(Effect.as(Exit.void)),
-          )
-          if (closed) break
-          if (exit._tag === "Failure" && firstFailure === undefined) firstFailure = exit.cause
-        }
-        if (firstFailure !== undefined) return yield* Effect.failCause(firstFailure)
-      })
-
-    const interrupt = (key: Key, seq?: number): Effect.Effect<void> =>
+    const interrupt = (key: Key): Effect.Effect<void> =>
       Effect.suspend(() => {
         const entry = active.get(key)
-        const latest = interruptSeq.get(key)
-        if (seq !== undefined && latest !== undefined && seq <= latest)
-          return entry?.stopping && entry.owner !== undefined ? Fiber.interrupt(entry.owner) : Effect.void
-        if (seq !== undefined) interruptSeq.set(key, seq)
         if (entry?.owner === undefined) return Effect.void
-        if (
-          seq !== undefined &&
-          entry.current._tag === "wake" &&
-          entry.current.seq !== undefined &&
-          entry.current.seq > seq
-        )
-          return Effect.void
-        if (entry.stopping) {
-          entry.interruptSeq = maxSeq(entry.interruptSeq, seq)
-          suppressPendingAtOrBefore(entry, seq)
-          return Fiber.interrupt(entry.owner)
-        }
         entry.stopping = true
-        entry.interruptSeq = seq
-        suppressPendingAtOrBefore(entry, seq)
+        entry.pendingWake = false
         return Fiber.interrupt(entry.owner)
       })
 
-    return { run, wake, awaitIdle, interrupt }
-
-    function run(key: Key): Effect.Effect<A, E> {
-      return Effect.uninterruptibleMask((restore) => {
-        if (closed) return Effect.interrupt
-        const entry = active.get(key)
-        if (entry !== undefined) {
-          if (entry.stopping) {
-            return restore(Deferred.await(entry.settled).pipe(Effect.andThen(run(key))))
-          }
-          if (entry.current._tag === "wake") {
-            entry.pending = coalesce(entry.pending, { _tag: "run" })
-            entry.explicitWaiter ??= Deferred.makeUnsafe<A, E>()
-            return restore(awaitRun(entry.explicitWaiter))
-          }
-          return restore(awaitRun(entry.done))
-        }
-
-        const next = makeEntry({ _tag: "run" })
-        active.set(key, next)
-        start(key, next, next.current)
-        return restore(awaitRun(next.done))
-      })
-    }
-
-    function awaitRun(done: Deferred.Deferred<A, E>): Effect.Effect<A, E> {
-      return Effect.raceFirst(Deferred.await(done), Deferred.await(shutdown).pipe(Effect.andThen(Effect.interrupt)))
-    }
-
-    function acceptsWake(entry: Entry<A, E>, seq: number | undefined) {
-      return !entry.stopping || (entry.interruptSeq !== undefined && seq !== undefined && seq > entry.interruptSeq)
-    }
-
-    function isAfterInterrupt(key: Key, seq: number | undefined) {
-      const latest = interruptSeq.get(key)
-      return latest === undefined || (seq !== undefined && seq > latest)
-    }
-
-    function suppressPendingAtOrBefore(entry: Entry<A, E>, seq: number | undefined) {
-      if (
-        entry.pending?._tag === "wake" &&
-        seq !== undefined &&
-        entry.pending.seq !== undefined &&
-        entry.pending.seq > seq
-      )
-        return
-      entry.pending = undefined
-    }
+    return { run, wake, interrupt }
   })
-
-export interface Interface extends Coordinator<SessionSchema.ID, void, SessionRunner.RunError> {}
-
-export class Service extends Context.Service<Service, Interface>()("@opencode/v2/SessionRunCoordinator") {}
-
-export const layer = Layer.effect(
-  Service,
-  SessionRunner.Service.pipe(
-    Effect.flatMap((runner) =>
-      make<SessionSchema.ID, void, SessionRunner.RunError>({
-        drain: (sessionID, mode) => runner.run({ sessionID, force: mode === "run" }),
-        onFailure: (sessionID, cause) => logFailure("Failed to drain Session", sessionID, cause),
-      }),
-    ),
-    Effect.map(Service.of),
-  ),
-)

packages/core/src/session/runner/index.ts

@@ -6,7 +6,6 @@ import { SessionSchema } from "../schema"
 import type { ContextSnapshotDecodeError, MessageDecodeError } from "../error"
 import { SessionRunnerModel } from "./model"
 import type { SystemContext } from "../../system-context/index"
-import type { SessionContextEpoch } from "../context-epoch"
 import type { ToolOutputStore } from "../../tool-output-store"
 
 export type RunError =
@@ -15,7 +14,6 @@ export type RunError =
   | MessageDecodeError
   | ContextSnapshotDecodeError
   | SystemContext.InitializationBlocked
-  | SessionContextEpoch.AgentReplacementBlocked
   | ToolOutputStore.Error
 
 /** Runs one local continuation from already-recorded Session history. */
@@ -23,7 +21,7 @@ export interface Interface {
   /** Drains eligible durable work. Explicit runs perform one provider attempt even when no work is eligible. */
   readonly run: (input: {
     readonly sessionID: SessionSchema.ID
-    readonly force?: boolean
+    readonly force: boolean
   }) => Effect.Effect<void, RunError>
 }
 

packages/core/src/session/runner/llm.ts

@@ -8,7 +8,7 @@ import {
   isContextOverflowFailure,
   type ProviderErrorEvent,
 } from "@opencode-ai/llm"
-import { Cause, DateTime, Effect, FiberSet, Layer, Option, Schema, Semaphore, Stream } from "effect"
+import { Cause, DateTime, Effect, FiberSet, Layer, Option, Semaphore, Stream } from "effect"
 import { AgentV2 } from "../../agent"
 import { Config } from "../../config"
 import { Database } from "../../database/database"
@@ -141,8 +141,8 @@ export const layer = Layer.effect(
       cause.reasons.some((reason) => Cause.isDieReason(reason) && reason.defect instanceof QuestionV2.RejectedError)
 
     type TurnTransition =
-      // Request preparation observed a concurrent Session change and must restart from durable state.
-      | { readonly _tag: "RebuildPreparedTurn"; readonly promotion?: SessionInput.Delivery }
+      // Automatic compaction completed; rebuild the request from compacted history.
+      | { readonly _tag: "ContinueAfterCompaction" }
       // Overflow compaction completed; rebuild once through the path without overflow recovery.
       | { readonly _tag: "ContinueAfterOverflowCompaction" }
 
@@ -152,20 +152,11 @@ export const layer = Layer.effect(
       }
     }
 
-    const rebuildPreparedTurn = (promotion?: SessionInput.Delivery) =>
-      new TurnTransitionError({ _tag: "RebuildPreparedTurn", promotion })
+    const continueAfterCompaction = new TurnTransitionError({ _tag: "ContinueAfterCompaction" })
     const continueAfterOverflowCompaction = new TurnTransitionError({
       _tag: "ContinueAfterOverflowCompaction",
     })
 
-    const retryAgentMismatch = (promotion: SessionInput.Delivery | undefined) =>
-      Effect.catchDefect((defect) =>
-        defect instanceof SessionContextEpoch.AgentMismatch
-          ? Effect.die(rebuildPreparedTurn(promotion))
-          : Effect.die(defect),
-      )
-
-    const sameModel = Schema.toEquivalence(Schema.UndefinedOr(ModelV2.Ref))
     const loadSystemContext = (agent: AgentV2.Selection) =>
       Effect.all([systemContext.load(), skillGuidance.load(agent), referenceGuidance.load()], {
         concurrency: "unbounded",
@@ -181,13 +172,7 @@ export const layer = Layer.effect(
       if (session.location.directory !== location.directory || session.location.workspaceID !== location.workspaceID)
         return yield* Effect.interrupt
       const agent = yield* agents.select(session.agent)
-      const initialized = yield* SessionContextEpoch.initialize(
-        db,
-        loadSystemContext(agent),
-        session.id,
-        session.location,
-        agent.id,
-      ).pipe(retryAgentMismatch(promotion))
+      const initialized = yield* SessionContextEpoch.initialize(db, loadSystemContext(agent), session.id)
       const toolFibers = yield* FiberSet.make<void, ToolOutputStore.Error>()
       let needsContinuation = false
       if (promotion) {
@@ -199,18 +184,7 @@ export const layer = Layer.effect(
         }
       }
       const system =
-        initialized ??
-        (yield* SessionContextEpoch.prepare(
-          db,
-          events,
-          loadSystemContext(agent),
-          session.id,
-          session.location,
-          agent.id,
-        ).pipe(retryAgentMismatch(undefined)))
-      const current = yield* getSession(sessionID)
-      if ((yield* agents.select(current.agent)).id !== agent.id || !sameModel(current.model, session.model))
-        return yield* Effect.die(rebuildPreparedTurn())
+        initialized ?? (yield* SessionContextEpoch.prepare(db, events, loadSystemContext(agent), session.id))
       const model = yield* models.resolve(session)
       const entries = yield* SessionHistory.entriesForRunner(db, session.id, system.baselineSeq)
       const context = entries.map((entry) => entry.message)
@@ -228,7 +202,7 @@ export const layer = Layer.effect(
         toolChoice: isLastStep ? "none" : undefined,
       })
       if (yield* compaction.compactIfNeeded({ sessionID: session.id, entries, model, request }))
-        return yield* Effect.die(rebuildPreparedTurn())
+        return yield* Effect.die(continueAfterCompaction)
       const publisher = createLLMEventPublisher(events, {
         sessionID: session.id,
         agent: agent.id,
@@ -242,8 +216,6 @@ export const layer = Layer.effect(
       const publish = (event: LLMEvent, outputPaths: ReadonlyArray<string> = []) =>
         withPublication(publisher.publish(event, outputPaths))
       let overflowFailure: ProviderErrorEvent | undefined
-      if (!(yield* SessionContextEpoch.current(db, session.id, agent.id, system.revision)))
-        return yield* Effect.die(rebuildPreparedTurn())
       const providerStream = llm.stream(request).pipe(
         Stream.runForEach((event) =>
           Effect.gen(function* () {
@@ -305,14 +277,7 @@ export const layer = Layer.effect(
           const llmFailure = failure instanceof LLMError ? failure : undefined
           if (llmFailure && !publisher.hasProviderError()) {
             yield* withPublication(publisher.failUnsettledTools("Provider did not return a tool result", true))
-            yield* withPublication(
-              events.publish(SessionEvent.Step.Failed, {
-                sessionID: session.id,
-                timestamp: yield* DateTime.now,
-                assistantMessageID: yield* publisher.startAssistant(),
-                error: { type: "unknown", message: llmFailure.reason.message },
-              }),
-            )
+            yield* withPublication(publisher.failAssistant(llmFailure.reason.message))
           }
           if (stream._tag === "Failure" && Cause.hasInterrupts(stream.cause)) yield* FiberSet.clear(toolFibers)
           const settled = yield* restore(awaitToolFibers(toolFibers)).pipe(Effect.exit)
@@ -327,6 +292,8 @@ export const layer = Layer.effect(
           ) {
             yield* FiberSet.clear(toolFibers)
             yield* withPublication(publisher.failUnsettledTools("Tool execution interrupted"))
+            if (publisher.hasActiveAssistant())
+              yield* withPublication(publisher.failAssistant("Provider turn interrupted"))
           }
           if (settled._tag === "Failure" && !Cause.hasInterrupts(settled.cause)) {
             const failure = Cause.squash(settled.cause)
@@ -357,7 +324,7 @@ export const layer = Layer.effect(
             if (defect.transition._tag === "ContinueAfterOverflowCompaction")
               return yield* Effect.die("Post-compaction provider attempt cannot recover another overflow")
             yield* Effect.yieldNow
-            return yield* runAfterOverflowCompaction(sessionID, defect.transition.promotion, step)
+            return yield* runAfterOverflowCompaction(sessionID, undefined, step)
           }),
         ),
       )
@@ -371,7 +338,7 @@ export const layer = Layer.effect(
             yield* Effect.yieldNow
             if (defect.transition._tag === "ContinueAfterOverflowCompaction")
               return yield* runAfterOverflowCompaction(sessionID, undefined, step)
-            return yield* runTurn(sessionID, defect.transition.promotion, step)
+            return yield* runTurn(sessionID, undefined, step)
           }),
         ),
       )
@@ -379,14 +346,14 @@ export const layer = Layer.effect(
 
     const run = Effect.fn("SessionRunner.run")(function* (input: {
       readonly sessionID: SessionSchema.ID
-      readonly force?: boolean
+      readonly force: boolean
     }) {
       const hasSteer = yield* SessionInput.hasPending(db, input.sessionID, "steer")
       const hasQueue = hasSteer ? false : yield* SessionInput.hasPending(db, input.sessionID, "queue")
-      if (input.force !== true && !hasSteer && !hasQueue) return
+      if (!input.force && !hasSteer && !hasQueue) return
       yield* failInterruptedTools(input.sessionID)
       let promotion: SessionInput.Delivery | undefined = hasSteer ? "steer" : hasQueue ? "queue" : undefined
-      let openActivity = input.force === true || hasSteer || hasQueue
+      let openActivity = input.force || hasSteer || hasQueue
       while (openActivity) {
         let needsContinuation = true
         for (let step = 1; needsContinuation; step++) {

packages/core/src/session/runner/model.ts

@@ -5,7 +5,7 @@ import * as AnthropicMessages from "@opencode-ai/llm/protocols/anthropic-message
 import * as OpenAICompatibleChat from "@opencode-ai/llm/protocols/openai-compatible-chat"
 import * as OpenAIResponses from "@opencode-ai/llm/protocols/openai-responses"
 import { Auth, type AnyRoute } from "@opencode-ai/llm/route"
-import { Context, Effect, Layer, Option, Schema } from "effect"
+import { Context, Effect, Layer, Schema } from "effect"
 import { produce } from "immer"
 import { Catalog } from "../../catalog"
 import { Credential } from "../../credential"
@@ -24,6 +24,23 @@ export class ModelNotSelectedError extends Schema.TaggedErrorClass<ModelNotSelec
   },
 ) {}
 
+export class ModelUnavailableError extends Schema.TaggedErrorClass<ModelUnavailableError>()(
+  "SessionRunnerModel.ModelUnavailableError",
+  {
+    providerID: ProviderV2.ID,
+    modelID: ModelV2.ID,
+  },
+) {}
+
+export class VariantUnavailableError extends Schema.TaggedErrorClass<VariantUnavailableError>()(
+  "SessionRunnerModel.VariantUnavailableError",
+  {
+    providerID: ProviderV2.ID,
+    modelID: ModelV2.ID,
+    variant: ModelV2.VariantID,
+  },
+) {}
+
 export class UnsupportedApiError extends Schema.TaggedErrorClass<UnsupportedApiError>()(
   "SessionRunnerModel.UnsupportedApiError",
   {
@@ -33,7 +50,7 @@ export class UnsupportedApiError extends Schema.TaggedErrorClass<UnsupportedApiE
   },
 ) {}
 
-export type Error = ModelNotSelectedError | UnsupportedApiError
+export type Error = ModelNotSelectedError | ModelUnavailableError | VariantUnavailableError | UnsupportedApiError
 
 export interface Interface {
   readonly resolve: (session: SessionSchema.Info) => Effect.Effect<Model, Error>
@@ -44,7 +61,7 @@ export class Service extends Context.Service<Service, Interface>()("@opencode/v2
 /** Test or embedding seam for supplying a model resolver directly. */
 export const layerWith = (resolve: Interface["resolve"]) => Layer.succeed(Service, Service.of({ resolve }))
 
-const apiKey = (model: ModelV2.Info, connection?: IntegrationConnection.Info, credential?: Credential.Stored) => {
+const apiKey = (model: ModelV2.Info, connection?: IntegrationConnection.Info, credential?: Credential.Info) => {
   if (credential?.value.type === "key") return Auth.value(credential.value.key)
   if (credential?.value.type === "oauth") return Auth.value(credential.value.access)
   const value = model.request.body.apiKey ?? model.api.settings?.apiKey
@@ -70,13 +87,27 @@ const withDefaults = (model: ModelV2.Info, route: AnyRoute) => {
   })
 }
 
-const withVariant = (model: ModelV2.Info, variantID: ModelV2.VariantID | undefined) => {
+const withVariant = (
+  model: ModelV2.Info,
+  variantID: ModelV2.VariantID | undefined,
+): Effect.Effect<ModelV2.Info, VariantUnavailableError> => {
   const id = variantID === "default" || variantID === undefined ? model.request.variant : variantID
   const variant = model.variants.find((item) => item.id === id)
-  if (!variant) return model
-  return produce(model, (draft) => {
-    ModelRequest.assign(draft.request, variant)
-  })
+  if (!variant && variantID !== undefined && variantID !== "default")
+    return Effect.fail(
+      new VariantUnavailableError({
+        providerID: model.providerID,
+        modelID: model.id,
+        variant: variantID,
+      }),
+    )
+  return Effect.succeed(
+    variant
+      ? produce(model, (draft) => {
+          ModelRequest.assign(draft.request, variant)
+        })
+      : model,
+  )
 }
 
 const apiName = (model: ModelV2.Info) =>
@@ -85,7 +116,7 @@ const apiName = (model: ModelV2.Info) =>
 export const fromCatalogModel = (
   model: ModelV2.Info,
   connection?: IntegrationConnection.Info,
-  credential?: Credential.Stored,
+  credential?: Credential.Info,
 ): Effect.Effect<Model, UnsupportedApiError> => {
   const resolved =
     credential?.value.metadata === undefined
@@ -124,8 +155,15 @@ export const fromCatalogModel = (
   )
 }
 
-export const resolve = (session: SessionSchema.Info, model: ModelV2.Info) =>
-  fromCatalogModel(withVariant(model, session.model?.variant))
+export const resolve = (
+  session: SessionSchema.Info,
+  model: ModelV2.Info,
+  connection?: IntegrationConnection.Info,
+  credential?: Credential.Info,
+) =>
+  withVariant(model, session.model?.variant).pipe(
+    Effect.flatMap((model) => fromCatalogModel(model, connection, credential)),
+  )
 
 export const supported = (model: ModelV2.Info) =>
   model.api.type === "aisdk" &&
@@ -147,14 +185,22 @@ export const locationLayer = Layer.effect(
         yield* boot.wait()
         const defaultModel = session.model ? undefined : yield* catalog.model.default()
         const selected = session.model
-          ? yield* catalog.model.get(session.model.providerID, session.model.id)
+          ? (yield* catalog.model.available()).find(
+              (model) => model.providerID === session.model?.providerID && model.id === session.model.id,
+            )
           : defaultModel && supported(defaultModel)
             ? defaultModel
             : (yield* catalog.model.available()).find(supported)
+        if (!selected && session.model)
+          return yield* new ModelUnavailableError({
+            providerID: session.model.providerID,
+            modelID: session.model.id,
+          })
         if (!selected) return yield* new ModelNotSelectedError({ sessionID: session.id })
         const connection = yield* integrations.connection.forIntegration(Integration.ID.make(selected.providerID))
-        return yield* fromCatalogModel(
-          withVariant(selected, session.model?.variant),
+        return yield* resolve(
+          session,
+          selected,
           connection,
           connection?.type === "credential" ? yield* credentials.get(connection.id) : undefined,
         )

packages/core/src/session/runner/publish-llm-event.ts

@@ -65,11 +65,14 @@ export const createLLMEventPublisher = (events: EventV2.Interface, input: Input)
   >()
   const timestamp = DateTime.now
   let assistantMessageID: SessionMessage.ID | undefined
+  let assistantActive = false
+  let assistantFailed = false
   let providerFailed = false
 
   const startAssistant = Effect.fnUntraced(function* () {
     if (assistantMessageID !== undefined) return assistantMessageID
     assistantMessageID = SessionMessage.ID.create()
+    assistantActive = true
     yield* events.publish(SessionEvent.Step.Started, {
       ...input,
       assistantMessageID,
@@ -190,6 +193,20 @@ export const createLLMEventPublisher = (events: EventV2.Interface, input: Input)
     yield* flushFragments()
   })
 
+  const failAssistant = Effect.fnUntraced(function* (message: string) {
+    if (assistantFailed) return
+    yield* flush()
+    const assistantMessageID = yield* startAssistant()
+    assistantActive = false
+    assistantFailed = true
+    yield* events.publish(SessionEvent.Step.Failed, {
+      sessionID: input.sessionID,
+      timestamp: yield* timestamp,
+      assistantMessageID,
+      error: { type: "unknown", message },
+    })
+  })
+
   const failUnsettledTools = Effect.fn("SessionRunner.failUnsettledTools")(function* (
     message: string,
     hostedOnly = false,
@@ -375,6 +392,7 @@ export const createLLMEventPublisher = (events: EventV2.Interface, input: Input)
       }
       case "step-finish":
         yield* flush()
+        assistantActive = false
         yield* events.publish(SessionEvent.Step.Ended, {
           sessionID: input.sessionID,
           timestamp: yield* timestamp,
@@ -388,13 +406,7 @@ export const createLLMEventPublisher = (events: EventV2.Interface, input: Input)
         return
       case "provider-error":
         providerFailed = true
-        yield* flush()
-        yield* events.publish(SessionEvent.Step.Failed, {
-          sessionID: input.sessionID,
-          timestamp: yield* timestamp,
-          assistantMessageID: yield* startAssistant(),
-          error: { type: "unknown", message: event.message },
-        })
+        yield* failAssistant(event.message)
         return
     }
   })
@@ -402,10 +414,11 @@ export const createLLMEventPublisher = (events: EventV2.Interface, input: Input)
   return {
     publish,
     flush,
+    failAssistant,
     failUnsettledTools,
+    hasActiveAssistant: () => assistantActive,
     hasAssistantStarted: () => assistantMessageID !== undefined,
     hasProviderError: () => providerFailed,
-    startAssistant,
     assistantMessageID: assistantMessageIDForTool,
   }
 }

packages/core/src/session/runner/to-llm-message.ts

@@ -82,12 +82,21 @@ const assistant = (message: SessionMessage.Assistant, model: Model) => {
     const result = toolResult(item, sameModel ? (item.provider?.resultMetadata ?? item.provider?.metadata) : undefined)
     return item.provider?.executed === true && result ? [call, result] : [call]
   })
+  const meaningful = content.filter((part) => {
+    if (part.type === "text") return part.text !== ""
+    if (part.type !== "reasoning") return true
+    return part.text !== "" || (part.providerMetadata !== undefined && Object.keys(part.providerMetadata).length > 0)
+  })
   const results = message.content
     .filter((item): item is SessionMessage.AssistantTool => item.type === "tool" && item.provider?.executed !== true)
     .map((item) => toolResult(item, sameModel ? (item.provider?.resultMetadata ?? item.provider?.metadata) : undefined))
     .filter((message) => message !== undefined)
     .map(Message.tool)
-  return [Message.make({ id: message.id, role: "assistant", content, metadata: message.metadata }), ...results]
+  if (meaningful.length === 0) return results
+  return [
+    Message.make({ id: message.id, role: "assistant", content: meaningful, metadata: message.metadata }),
+    ...results,
+  ]
 }
 
 function toLLMMessage(message: SessionMessage.Message, model: Model): Message[] {

packages/core/src/session/sql.ts

@@ -170,9 +170,6 @@ export const SessionContextEpochTable = sqliteTable("session_context_epoch", {
     .primaryKey()
     .references(() => SessionTable.id, { onDelete: "cascade" }),
   baseline: text().notNull(),
-  agent: text().$type<AgentV2.ID>().notNull().default(AgentV2.defaultID),
   snapshot: text({ mode: "json" }).notNull().$type<SystemContext.Snapshot>(),
   baseline_seq: integer().notNull(),
-  replacement_seq: integer(),
-  revision: integer().notNull().default(0),
 })

packages/core/src/tool/http-body.ts

@@ -0,0 +1,30 @@
+import { Effect, Stream } from "effect"
+import { HttpClientResponse } from "effect/unstable/http"
+
+export const collectBoundedResponseBody = (
+  response: HttpClientResponse.HttpClientResponse,
+  maximumBytes: number,
+  tooLarge: () => Error,
+) =>
+  Effect.gen(function* () {
+    const contentLength = response.headers["content-length"]
+    const parsedSize = contentLength ? Number.parseInt(contentLength, 10) : undefined
+    const declaredSize =
+      parsedSize !== undefined && Number.isSafeInteger(parsedSize) && parsedSize >= 0 ? parsedSize : undefined
+    if (declaredSize !== undefined && declaredSize > maximumBytes) return yield* Effect.fail(tooLarge())
+    let body = Buffer.allocUnsafe(Math.min(maximumBytes, declaredSize || 64 * 1024))
+    let size = 0
+    yield* Stream.runForEach(response.stream, (chunk) => {
+      if (chunk.byteLength === 0) return Effect.void
+      if (size + chunk.byteLength > maximumBytes) return Effect.fail(tooLarge())
+      if (size + chunk.byteLength > body.byteLength) {
+        const grown = Buffer.allocUnsafe(Math.min(maximumBytes, Math.max(size + chunk.byteLength, body.byteLength * 2)))
+        body.copy(grown, 0, 0, size)
+        body = grown
+      }
+      body.set(chunk, size)
+      size += chunk.byteLength
+      return Effect.void
+    })
+    return body.subarray(0, size)
+  })

packages/core/src/tool/read-filesystem.ts

@@ -13,23 +13,61 @@ export const MAX_MEDIA_INGEST_BYTES = 20 * 1024 * 1024
 const MAX_LINE_LENGTH = 2_000
 const MAX_LINE_SUFFIX = `... (line truncated to ${MAX_LINE_LENGTH} chars)`
 
-export class BinaryFileError extends Error {
-  constructor(readonly resource: string) {
-    super(`Cannot read binary file: ${resource}`)
-    this.name = "BinaryFileError"
+export class BinaryFileError extends Schema.TaggedErrorClass<BinaryFileError>()("ReadTool.BinaryFileError", {
+  resource: Schema.String,
+}) {
+  override get message() {
+    return `Cannot read binary file: ${this.resource}`
   }
 }
 
-export class MediaIngestLimitError extends Error {
-  constructor(
-    readonly resource: string,
-    readonly maximumBytes: number,
-  ) {
-    super(`Media exceeds ${maximumBytes} byte ingestion limit: ${resource}`)
-    this.name = "MediaIngestLimitError"
+export class MediaIngestLimitError extends Schema.TaggedErrorClass<MediaIngestLimitError>()(
+  "ReadTool.MediaIngestLimitError",
+  {
+    resource: Schema.String,
+    maximumBytes: Schema.Number,
+  },
+) {
+  override get message() {
+    return `Media exceeds ${this.maximumBytes} byte ingestion limit: ${this.resource}`
   }
 }
 
+export class MalformedUtf8Error extends Schema.TaggedErrorClass<MalformedUtf8Error>()("ReadTool.MalformedUtf8Error", {
+  resource: Schema.String,
+}) {
+  override get message() {
+    return `File is not valid UTF-8: ${this.resource}`
+  }
+}
+
+export class OffsetOutOfRangeError extends Schema.TaggedErrorClass<OffsetOutOfRangeError>()(
+  "ReadTool.OffsetOutOfRangeError",
+  { offset: Schema.Number },
+) {
+  override get message() {
+    return `Offset ${this.offset} is out of range`
+  }
+}
+
+export class PathKindError extends Schema.TaggedErrorClass<PathKindError>()("ReadTool.PathKindError", {
+  resource: Schema.String,
+  expected: Schema.Literals(["a file", "a file or directory"]),
+}) {
+  override get message() {
+    return `Path is not ${this.expected}: ${this.resource}`
+  }
+}
+
+export type InspectError = FSUtil.Error | PathKindError
+export type ReadError =
+  | FSUtil.Error
+  | BinaryFileError
+  | MediaIngestLimitError
+  | MalformedUtf8Error
+  | OffsetOutOfRangeError
+  | PathKindError
+
 export const PageInput = Schema.Struct({
   offset: PositiveInt.pipe(Schema.optional),
   limit: PositiveInt.check(Schema.isLessThanOrEqualTo(MAX_READ_LINES)).pipe(Schema.optional),
@@ -52,13 +90,13 @@ export class ListPage extends Schema.Class<ListPage>("ReadTool.ListPage")({
 }) {}
 
 export interface Interface {
-  readonly inspect: (path: AbsolutePath) => Effect.Effect<"file" | "directory">
+  readonly inspect: (path: AbsolutePath) => Effect.Effect<"file" | "directory", InspectError>
   readonly read: (
     path: AbsolutePath,
     resource: string,
     page?: PageInput,
-  ) => Effect.Effect<FileSystem.Content | TextPage>
-  readonly list: (path: AbsolutePath, page?: PageInput) => Effect.Effect<ListPage>
+  ) => Effect.Effect<FileSystem.Content | TextPage, ReadError>
+  readonly list: (path: AbsolutePath, page?: PageInput) => Effect.Effect<ListPage, FSUtil.Error>
 }
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/ReadToolFileSystem") {}
@@ -111,11 +149,21 @@ const binary = (resource: string, bytes: Uint8Array) => {
   }
   return nonPrintable / bytes.length > 0.3
 }
+const decodeUtf8 = (resource: string, decoder: TextDecoder, bytes?: Uint8Array) =>
+  Effect.try({
+    try: () => decoder.decode(bytes, { stream: bytes !== undefined }),
+    catch: (error) => {
+      if (error instanceof TypeError) return new MalformedUtf8Error({ resource })
+      throw error
+    },
+  })
+const decodeChunk = (resource: string, decoder: TextDecoder, bytes: Uint8Array) =>
+  bytes.includes(0) ? Effect.fail(new BinaryFileError({ resource })) : decodeUtf8(resource, decoder, bytes)
 
 export const inspect = Effect.fn("ReadTool.inspect")(function* (fs: FSUtil.Interface, input: string) {
-  const info = yield* fs.stat(input).pipe(Effect.orDie)
+  const info = yield* fs.stat(input)
   const type = info.type === "File" ? "file" : info.type === "Directory" ? "directory" : undefined
-  if (!type) return yield* Effect.die(new Error("Path is not a file or directory"))
+  if (!type) return yield* Effect.fail(new PathKindError({ resource: input, expected: "a file or directory" }))
   return type
 })
 
@@ -125,32 +173,30 @@ export const read = Effect.fn("ReadTool.read")(function* (
   resource: string,
   page: PageInput = {},
 ) {
-  const real = yield* fs.realPath(input).pipe(Effect.orDie)
+  const real = yield* fs.realPath(input)
   return yield* Effect.scoped(
     Effect.gen(function* () {
-      const file = yield* fs.open(real, { flag: "r" }).pipe(Effect.orDie)
-      const info = yield* file.stat.pipe(Effect.orDie)
-      if (info.type !== "File") return yield* Effect.die(new Error("Path is not a file"))
+      const file = yield* fs.open(real, { flag: "r" })
+      const info = yield* file.stat
+      if (info.type !== "File") return yield* Effect.fail(new PathKindError({ resource, expected: "a file" }))
       const first = Option.getOrElse(
-        yield* file.readAlloc(Math.min(64 * 1024, Number(info.size) || 4 * 1024)).pipe(Effect.orDie),
+        yield* file.readAlloc(Math.min(64 * 1024, Number(info.size) || 4 * 1024)),
         () => new Uint8Array(),
       )
       const mime = imageMime(first)
       if (mime) {
         if (info.size > MAX_MEDIA_INGEST_BYTES)
-          return yield* Effect.die(new MediaIngestLimitError(resource, MAX_MEDIA_INGEST_BYTES))
+          return yield* Effect.fail(new MediaIngestLimitError({ resource, maximumBytes: MAX_MEDIA_INGEST_BYTES }))
         const chunks = [first]
         let total = first.length
         while (total <= MAX_MEDIA_INGEST_BYTES) {
-          const chunk = yield* file
-            .readAlloc(Math.min(64 * 1024, MAX_MEDIA_INGEST_BYTES + 1 - total))
-            .pipe(Effect.orDie)
+          const chunk = yield* file.readAlloc(Math.min(64 * 1024, MAX_MEDIA_INGEST_BYTES + 1 - total))
           if (Option.isNone(chunk)) break
           chunks.push(chunk.value)
           total += chunk.value.length
         }
         if (total > MAX_MEDIA_INGEST_BYTES)
-          return yield* Effect.die(new MediaIngestLimitError(resource, MAX_MEDIA_INGEST_BYTES))
+          return yield* Effect.fail(new MediaIngestLimitError({ resource, maximumBytes: MAX_MEDIA_INGEST_BYTES }))
         return {
           uri: pathToFileURL(real).href,
           name: path.basename(real),
@@ -162,19 +208,19 @@ export const read = Effect.fn("ReadTool.read")(function* (
           mime,
         }
       }
-      if (startsWith(first, [0x25, 0x50, 0x44, 0x46]) || binary(resource, first))
-        return yield* Effect.die(new BinaryFileError(resource))
+      if (startsWith(first, [0x25, 0x50, 0x44, 0x46]) || extensions.has(path.extname(resource).toLowerCase()))
+        return yield* Effect.fail(new BinaryFileError({ resource }))
       const paged = info.size > MAX_READ_BYTES || page.offset !== undefined || page.limit !== undefined
       if (!paged) {
+        if (binary(resource, first)) return yield* Effect.fail(new BinaryFileError({ resource }))
         const decoder = new TextDecoder("utf-8", { fatal: true })
-        const text = [yield* Effect.sync(() => decoder.decode(first, { stream: true }))]
+        const text = [yield* decodeUtf8(resource, decoder, first)]
         while (true) {
-          const chunk = yield* file.readAlloc(64 * 1024).pipe(Effect.orDie)
+          const chunk = yield* file.readAlloc(64 * 1024)
           if (Option.isNone(chunk)) break
-          if (chunk.value.includes(0)) return yield* Effect.die(new BinaryFileError(resource))
-          text.push(yield* Effect.sync(() => decoder.decode(chunk.value, { stream: true })))
+          text.push(yield* decodeChunk(resource, decoder, chunk.value))
         }
-        text.push(yield* Effect.sync(() => decoder.decode()))
+        text.push(yield* decodeUtf8(resource, decoder))
         return {
           uri: pathToFileURL(real).href,
           name: path.basename(real),
@@ -191,34 +237,29 @@ export const read = Effect.fn("ReadTool.read")(function* (
       let discard = false
       let line = 1
       let bytes = 0
-      let found = false
-      let truncated = false
       let next: number | undefined
       const append = (input: string) => {
         if (line < offset) {
           line++
-          return
+          return true
         }
         if (lines.length >= limit || bytes >= MAX_READ_BYTES) {
-          truncated = true
-          next ??= line++
-          return
+          next = line
+          return false
         }
-        found = true
         const text = input.length > MAX_LINE_LENGTH ? input.slice(0, MAX_LINE_LENGTH) + MAX_LINE_SUFFIX : input
         const size = Buffer.byteLength(text, "utf-8") + (lines.length > 0 ? 1 : 0)
         if (bytes + size > MAX_READ_BYTES) {
-          truncated = true
-          next ??= line++
-          return
+          next = line
+          return false
         }
         lines.push(text)
         bytes += size
         line++
+        return true
       }
-      const consume = (chunk: Uint8Array) => {
-        if (chunk.includes(0)) throw new BinaryFileError(resource)
-        let text = decoder.decode(chunk, { stream: true })
+      const consume = (input: string) => {
+        let text = input
         while (true) {
           const index = text.indexOf("\n")
           if (index === -1) {
@@ -235,25 +276,44 @@ export const read = Effect.fn("ReadTool.read")(function* (
           pending = ""
           discard = false
           text = text.slice(index + 1)
-          append(current.endsWith("\r") ? current.slice(0, -1) : current)
+          if (!append(current.endsWith("\r") ? current.slice(0, -1) : current)) return false
         }
+        return true
       }
-      yield* Effect.sync(() => consume(first))
-      while (true) {
-        const chunk = yield* file.readAlloc(64 * 1024).pipe(Effect.orDie)
+      const consumeChunk = Effect.fnUntraced(function* (chunk: Uint8Array) {
+        let start = 0
+        while (start < chunk.length) {
+          if (lines.length >= limit || bytes >= MAX_READ_BYTES) {
+            next = line
+            return false
+          }
+          const newline = chunk.indexOf(10, start)
+          const end = newline === -1 ? chunk.length : newline + 1
+          const segment = chunk.subarray(start, end)
+          if (binary(resource, segment)) return yield* Effect.fail(new BinaryFileError({ resource }))
+          if (!consume(yield* decodeUtf8(resource, decoder, segment))) return false
+          start = end
+        }
+        return true
+      })
+      let done = !(yield* consumeChunk(first))
+      while (!done) {
+        const chunk = yield* file.readAlloc(64 * 1024)
         if (Option.isNone(chunk)) break
-        yield* Effect.sync(() => consume(chunk.value))
+        done = !(yield* consumeChunk(chunk.value))
       }
-      const tail = yield* Effect.sync(() => decoder.decode())
-      if (!discard) pending += tail
-      if (pending) append(pending.endsWith("\r") ? pending.slice(0, -1) : pending)
-      if (!found && offset !== 1) return yield* Effect.die(new Error(`Offset ${offset} is out of range`))
+      if (!done) {
+        const tail = yield* decodeUtf8(resource, decoder)
+        if (!discard) pending += tail
+        if (pending) append(pending.endsWith("\r") ? pending.slice(0, -1) : pending)
+      }
+      if (lines.length === 0 && offset !== 1) return yield* Effect.fail(new OffsetOutOfRangeError({ offset }))
       return new TextPage({
         type: "text-page",
         content: lines.join("\n"),
         mime: FSUtil.mimeType(real),
         offset,
-        truncated,
+        truncated: next !== undefined,
         ...(next === undefined ? {} : { next }),
       })
     }),
@@ -261,8 +321,8 @@ export const read = Effect.fn("ReadTool.read")(function* (
 })
 
 export const list = Effect.fn("ReadTool.list")(function* (fs: FSUtil.Interface, input: string, page: PageInput = {}) {
-  const real = yield* fs.realPath(input).pipe(Effect.orDie)
-  const items = yield* fs.readDirectoryEntries(real).pipe(Effect.orDie)
+  const real = yield* fs.realPath(input)
+  const items = yield* fs.readDirectoryEntries(real)
   const offset = page.offset ?? 1
   const limit = Math.min(page.limit ?? MAX_READ_LINES, MAX_READ_LINES)
   const entries = yield* Effect.forEach(

packages/core/src/tool/read.ts

@@ -57,8 +57,8 @@ export const layer = Layer.effectDiscard(
               const selected = path.isAbsolute(input.path) ? path.dirname(absolute) : location.directory
               if (!path.isAbsolute(input.path) && !FSUtil.contains(location.directory, absolute))
                 return yield* Effect.die(new Error("Path escapes the allowed read root"))
-              const real = yield* fs.realPath(absolute).pipe(Effect.orDie)
-              const root = yield* fs.realPath(selected).pipe(Effect.orDie)
+              const real = yield* fs.realPath(absolute)
+              const root = yield* fs.realPath(selected)
               if (!FSUtil.contains(root, real))
                 return yield* Effect.die(new Error("Path escapes the allowed read root"))
               const resource = path.relative(root, real).replaceAll("\\", "/") || "."
@@ -83,7 +83,7 @@ export const layer = Layer.effectDiscard(
                   .pipe(Effect.catchTag("Image.ResizerUnavailableError", () => Effect.succeed(content)))
               }
               if ("encoding" in content && content.encoding === "base64")
-                return yield* Effect.fail(new ReadToolFileSystem.BinaryFileError(resource))
+                return yield* Effect.fail(new ReadToolFileSystem.BinaryFileError({ resource }))
               return content
             }).pipe(
               Effect.mapError((error) => {

packages/core/src/tool/webfetch.ts

@@ -1,11 +1,12 @@
 export * as WebFetchTool from "./webfetch"
 
 import { ToolFailure } from "@opencode-ai/llm"
-import { Duration, Effect, Layer, Schema, Stream } from "effect"
+import { Duration, Effect, Layer, Schema } from "effect"
 import { HttpClient, HttpClientRequest, HttpClientResponse } from "effect/unstable/http"
 import { Parser } from "htmlparser2"
 import TurndownService from "turndown"
 import { PermissionV2 } from "../permission"
+import { collectBoundedResponseBody } from "./http-body"
 import { Tool } from "./tool"
 import { Tools } from "./tools"
 
@@ -86,24 +87,11 @@ const execute = (http: HttpClient.HttpClient, url: string, format: Format, userA
   http.execute(request(url, format, userAgent)).pipe(Effect.flatMap(HttpClientResponse.filterStatusOk))
 
 const collectBody = (response: HttpClientResponse.HttpClientResponse) =>
-  Effect.gen(function* () {
-    const contentLength = response.headers["content-length"]
-    if (contentLength && Number.parseInt(contentLength, 10) > MAX_RESPONSE_BYTES) {
-      return yield* Effect.fail(new Error(`Response too large (exceeds ${MAX_RESPONSE_BYTES} byte limit)`))
-    }
-    const chunks: Uint8Array[] = []
-    let size = 0
-    yield* Stream.runForEach(response.stream, (chunk) =>
-      Effect.gen(function* () {
-        size += chunk.byteLength
-        if (size > MAX_RESPONSE_BYTES)
-          return yield* Effect.fail(new Error(`Response too large (exceeds ${MAX_RESPONSE_BYTES} byte limit)`))
-        chunks.push(chunk)
-        return undefined
-      }),
-    )
-    return Buffer.concat(chunks, size)
-  })
+  collectBoundedResponseBody(
+    response,
+    MAX_RESPONSE_BYTES,
+    () => new Error(`Response too large (exceeds ${MAX_RESPONSE_BYTES} byte limit)`),
+  )
 
 const mimeFrom = (contentType: string) => contentType.split(";", 1)[0]?.trim().toLowerCase() ?? ""
 const isImageAttachment = (mime: string) =>
@@ -171,12 +159,16 @@ export const layer = Layer.effectDiscard(
                   orElse: () => Effect.fail(new Error("Request timed out")),
                 }),
               )
-              const content = convert(new TextDecoder().decode(body), contentType, input.format)
+              const content = new TextDecoder().decode(body)
+              const output = yield* Effect.try({
+                try: () => convert(content, contentType, input.format),
+                catch: (error) => error,
+              })
               return {
                 url: input.url,
                 contentType,
                 format: input.format,
-                output: content,
+                output,
               }
             }).pipe(Effect.mapError(() => new ToolFailure({ message: `Unable to fetch ${input.url}` }))),
         }),

packages/core/src/tool/websearch.ts

@@ -9,6 +9,7 @@ import { PositiveInt } from "../schema"
 import { PermissionV2 } from "../permission"
 import { Tool } from "./tool"
 import { Tools } from "./tools"
+import { collectBoundedResponseBody } from "./http-body"
 import { checksum } from "../util/encode"
 
 export const name = "websearch"
@@ -164,10 +165,12 @@ const callMcp = <F extends Schema.Struct.Fields>(
     )
     return yield* Effect.gen(function* () {
       const response = yield* HttpClient.filterStatusOk(http).execute(request)
-      const body = yield* response.text
-      if (Buffer.byteLength(body, "utf8") > MAX_RESPONSE_BYTES)
-        return yield* Effect.fail(new Error(`${tool} response exceeded ${MAX_RESPONSE_BYTES} bytes`))
-      return yield* parseResponse(body)
+      const body = yield* collectBoundedResponseBody(
+        response,
+        MAX_RESPONSE_BYTES,
+        () => new Error(`${tool} response exceeded ${MAX_RESPONSE_BYTES} bytes`),
+      )
+      return yield* parseResponse(body.toString("utf8"))
     }).pipe(
       Effect.timeoutOrElse({
         duration: Duration.seconds(25),

packages/core/test/catalog.test.ts

@@ -11,7 +11,11 @@ import { ProviderV2 } from "@opencode-ai/core/provider"
 import { AbsolutePath } from "@opencode-ai/core/schema"
 import { location } from "./fixture/location"
 import { testEffect } from "./lib/effect"
-import { required } from "./plugin/provider-helper"
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
 
 const locationLayer = Layer.succeed(
   Location.Service,
@@ -21,12 +25,7 @@ const it = testEffect(
   Catalog.locationLayer.pipe(
     Layer.provideMerge(EventV2.defaultLayer),
     Layer.provideMerge(locationLayer),
-    Layer.provideMerge(
-      Layer.mock(Credential.Service)({
-        all: () => Effect.succeed([]),
-        list: () => Effect.succeed([]),
-      }),
-    ),
+    Layer.provideMerge(Credential.defaultLayer),
   ),
 )
 
@@ -48,38 +47,30 @@ describe("CatalogV2", () => {
 
   it.effect("derives availability from active credentials without changing provider state", () => {
     const integrationID = Integration.ID.make("test")
-    const first = {
-      id: Credential.ID.create(),
-      integrationID,
-      label: "First",
-      value: new Credential.Key({ type: "key", key: "first", metadata: { tenant: "one" } }),
-    }
-    const second = {
-      id: Credential.ID.create(),
-      integrationID,
-      label: "Second",
-      value: new Credential.Key({ type: "key", key: "second", metadata: { tenant: "two" } }),
-    }
-    let active = first
     const layer = Catalog.locationLayer.pipe(
       Layer.fresh,
       Layer.provideMerge(EventV2.defaultLayer),
       Layer.provideMerge(locationLayer),
-      Layer.provideMerge(
-        Layer.mock(Credential.Service)({
-          all: () => Effect.sync(() => [active]),
-          list: () => Effect.sync(() => [active]),
-        }),
-      ),
+      Layer.provideMerge(Credential.defaultLayer.pipe(Layer.fresh)),
     )
 
     return Effect.gen(function* () {
       const catalog = yield* Catalog.Service
+      const credentials = yield* Credential.Service
       yield* catalog.transform((editor) => editor.provider.update(ProviderV2.ID.make("test"), () => {}))
+      yield* credentials.create({
+        integrationID,
+        label: "First",
+        value: new Credential.Key({ type: "key", key: "first", metadata: { tenant: "one" } }),
+      })
 
       expect((yield* catalog.provider.available()).map((provider) => provider.id)).toEqual([ProviderV2.ID.make("test")])
       expect(required(yield* catalog.provider.get(ProviderV2.ID.make("test"))).request.body).toEqual({})
-      active = second
+      yield* credentials.create({
+        integrationID,
+        label: "Second",
+        value: new Credential.Key({ type: "key", key: "second", metadata: { tenant: "two" } }),
+      })
       expect((yield* catalog.provider.available()).map((provider) => provider.id)).toEqual([ProviderV2.ID.make("test")])
       expect(required(yield* catalog.provider.get(ProviderV2.ID.make("test"))).request.body).toEqual({})
     }).pipe(Effect.provide(layer))

packages/core/test/config/provider.test.ts

@@ -1,14 +1,52 @@
 import { describe, expect } from "bun:test"
-import { Effect, Option, Schema } from "effect"
+import { Effect, Schema } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { Config } from "@opencode-ai/core/config"
 import { ConfigProviderPlugin } from "@opencode-ai/core/config/plugin/provider"
 import { Integration } from "@opencode-ai/core/integration"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { it, required, withEnv } from "../plugin/provider-helper"
-import { catalogHost, host, integrationHost } from "../plugin/host"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "../plugin/fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* (config: Config.Interface) {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({
+    ...ConfigProviderPlugin.Plugin,
+    effect: ConfigProviderPlugin.Plugin.effect(host).pipe(Effect.provideService(Config.Service, config)),
+  })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, effect: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    effect,
+    (previous) =>
+      Effect.sync(() =>
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        }),
+      ),
+  )
+}
 
 function request(headers: Record<string, string>, variant?: string) {
   return {
@@ -23,8 +61,6 @@ describe("ConfigProviderPlugin.Plugin", () => {
   it.effect("partitions existing model variant bodies without changing config shape", () =>
     Effect.gen(function* () {
       const catalog = yield* Catalog.Service
-      const integrations = yield* Integration.Service
-      const plugin = yield* PluginV2.Service
       const providerID = ProviderV2.ID.opencode
       const modelID = ModelV2.ID.make("alpha-gpt-next")
       const config = Config.Service.of({
@@ -57,12 +93,7 @@ describe("ConfigProviderPlugin.Plugin", () => {
           ]),
       })
 
-      yield* plugin.add({
-        ...ConfigProviderPlugin.Plugin,
-        effect: ConfigProviderPlugin.Plugin.effect(
-          host({ catalog: catalogHost(catalog), integration: integrationHost(integrations) }),
-        ).pipe(Effect.provideService(Config.Service, config)),
-      })
+      yield* addPlugin(config)
 
       const model = required(yield* catalog.model.get(providerID, modelID))
       expect(model.variants).toMatchObject([
@@ -82,8 +113,6 @@ describe("ConfigProviderPlugin.Plugin", () => {
   it.effect("uses the effective provider package across layered config", () =>
     Effect.gen(function* () {
       const catalog = yield* Catalog.Service
-      const integrations = yield* Integration.Service
-      const plugin = yield* PluginV2.Service
       const providerID = ProviderV2.ID.opencode
       const modelID = ModelV2.ID.make("alpha-gpt-next")
       const config = Config.Service.of({
@@ -116,12 +145,7 @@ describe("ConfigProviderPlugin.Plugin", () => {
           ]),
       })
 
-      yield* plugin.add({
-        ...ConfigProviderPlugin.Plugin,
-        effect: ConfigProviderPlugin.Plugin.effect(
-          host({ catalog: catalogHost(catalog), integration: integrationHost(integrations) }),
-        ).pipe(Effect.provideService(Config.Service, config)),
-      })
+      yield* addPlugin(config)
 
       const model = required(yield* catalog.model.get(providerID, modelID))
       expect(model.variants[0]).toMatchObject({
@@ -137,7 +161,6 @@ describe("ConfigProviderPlugin.Plugin", () => {
       Effect.gen(function* () {
         const catalog = yield* Catalog.Service
         const integrations = yield* Integration.Service
-        const plugin = yield* PluginV2.Service
         const providerID = ProviderV2.ID.make("custom")
         const modelID = ModelV2.ID.make("chat")
         const config = Config.Service.of({
@@ -217,12 +240,7 @@ describe("ConfigProviderPlugin.Plugin", () => {
             ]),
         })
 
-        yield* plugin.add({
-          ...ConfigProviderPlugin.Plugin,
-          effect: ConfigProviderPlugin.Plugin.effect(
-            host({ catalog: catalogHost(catalog), integration: integrationHost(integrations) }),
-          ).pipe(Effect.provideService(Config.Service, config)),
-        })
+        yield* addPlugin(config)
 
         const provider = required(yield* catalog.provider.get(providerID))
         const model = required(yield* catalog.model.get(providerID, modelID))

packages/core/test/credential.test.ts

@@ -1,49 +1,35 @@
-import path from "path"
 import { describe, expect } from "bun:test"
-import { Effect, Layer } from "effect"
+import { Effect } from "effect"
 import { Credential } from "@opencode-ai/core/credential"
-import { Database } from "@opencode-ai/core/database/database"
 import { Integration } from "@opencode-ai/core/integration"
-import { tmpdir } from "./fixture/tmpdir"
-import { it } from "./lib/effect"
+import { testEffect } from "./lib/effect"
 
-function layer(directory: string) {
-  return Credential.layer.pipe(
-    Layer.provide(Database.layerFromPath(path.join(directory, "credential.db")).pipe(Layer.fresh)),
-  )
-}
+const it = testEffect(Credential.defaultLayer)
 
 describe("Credential", () => {
-  it.live("stores, updates, lists, and removes credentials", () =>
-    Effect.acquireRelease(
-      Effect.promise(() => tmpdir()),
-      (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
-    ).pipe(
-      Effect.flatMap((tmp) =>
-        Effect.gen(function* () {
-          const credentials = yield* Credential.Service
-          const integrationID = Integration.ID.make("openai")
-          const created = yield* credentials.create({
-            integrationID,
-            label: "Work",
-            value: new Credential.Key({ type: "key", key: "secret" }),
-          })
+  it.effect("stores, updates, lists, and removes credentials", () =>
+    Effect.gen(function* () {
+      const credentials = yield* Credential.Service
+      const integrationID = Integration.ID.make("openai")
+      const created = yield* credentials.create({
+        integrationID,
+        label: "Work",
+        value: new Credential.Key({ type: "key", key: "secret" }),
+      })
 
-          expect(yield* credentials.list(integrationID)).toEqual([created])
-          yield* credentials.update(created.id, { label: "Personal" })
-          expect((yield* credentials.list(integrationID))[0]?.label).toBe("Personal")
+      expect(yield* credentials.list(integrationID)).toEqual([created])
+      yield* credentials.update(created.id, { label: "Personal" })
+      expect((yield* credentials.list(integrationID))[0]?.label).toBe("Personal")
 
-          const replacement = yield* credentials.create({
-            integrationID,
-            label: "Replacement",
-            value: new Credential.Key({ type: "key", key: "replacement" }),
-          })
-          expect(yield* credentials.list(integrationID)).toEqual([replacement])
+      const replacement = yield* credentials.create({
+        integrationID,
+        label: "Replacement",
+        value: new Credential.Key({ type: "key", key: "replacement" }),
+      })
+      expect(yield* credentials.list(integrationID)).toEqual([replacement])
 
-          yield* credentials.remove(replacement.id)
-          expect(yield* credentials.list(integrationID)).toEqual([])
-        }).pipe(Effect.provide(layer(tmp.path))),
-      ),
-    ),
+      yield* credentials.remove(replacement.id)
+      expect(yield* credentials.list(integrationID)).toEqual([])
+    }),
   )
 })

packages/core/test/database-migration.test.ts

@@ -71,9 +71,9 @@ describe("DatabaseMigration", () => {
         ).toEqual({ name: "session_context_epoch" })
         expect(
           yield* db.get(
-            sql`SELECT name, dflt_value FROM pragma_table_info('session_context_epoch') WHERE name = 'agent'`,
+            sql`SELECT name FROM pragma_table_info('session_context_epoch') WHERE name IN ('agent', 'replacement_seq', 'revision')`,
           ),
-        ).toEqual({ name: "agent", dflt_value: "'build'" })
+        ).toBeUndefined()
         expect(yield* db.get(sql`SELECT count(*) as count FROM migration`)).toEqual({ count: migrations.length })
         expect(
           yield* db.all(

packages/core/test/event.test.ts

@@ -420,13 +420,12 @@ describe("EventV2", () => {
       const readStarted = yield* Deferred.make<void>()
       const continueRead = yield* Deferred.make<void>()
       let pause = true
-      const database = Database.layerFromPath(":memory:")
       const eventLayer = EventV2.layerWith({
         beforeAggregateRead: () =>
           pause
             ? Deferred.succeed(readStarted, undefined).pipe(Effect.andThen(Deferred.await(continueRead)))
             : Effect.void,
-      }).pipe(Layer.provide(database))
+      }).pipe(Layer.provide(Database.defaultLayer))
 
       yield* Effect.gen(function* () {
         const events = yield* EventV2.Service
@@ -441,7 +440,7 @@ describe("EventV2", () => {
         expect(Array.from(yield* Fiber.join(fiber)).map((event) => [event.durable?.seq, event.data])).toEqual([
           [0, { id: aggregateID, text: "during handoff" }],
         ])
-      }).pipe(Effect.provide(Layer.mergeAll(database, eventLayer)))
+      }).pipe(Effect.provide(Layer.mergeAll(Database.defaultLayer, eventLayer)))
     }),
   )
 

packages/core/test/filesystem/filesystem.test.ts

@@ -5,7 +5,7 @@ import { FSUtil } from "@opencode-ai/core/fs-util"
 import { testEffect } from "../lib/effect"
 import path from "path"
 
-const live = FSUtil.layer.pipe(Layer.provideMerge(NodeFileSystem.layer))
+const live = Layer.merge(FSUtil.defaultLayer, NodeFileSystem.layer)
 const { effect: it } = testEffect(live)
 
 describe("FSUtil", () => {

packages/core/test/filesystem/search.test.ts

@@ -22,7 +22,7 @@ describe("Ripgrep", () => {
         yield* Effect.promise(() => fs.mkdir(path.join(cwd, "src")))
         yield* Effect.promise(() => fs.writeFile(path.join(cwd, "src", "match.ts"), "needle\n"))
         const result = yield* (yield* Ripgrep.Service).glob({ cwd, pattern: "**/*.ts", limit: 10 })
-        expect(result.map((item) => item.path)).toEqual([RelativePath.make(path.join("src", "match.ts"))])
+        expect(result.map((item) => item.path)).toEqual([RelativePath.make("src/match.ts")])
       }),
     ),
   )
@@ -35,7 +35,7 @@ describe("Ripgrep", () => {
         yield* Effect.promise(() => fs.writeFile(path.join(cwd, "src", "skip.txt"), "needle\n"))
         const result = yield* (yield* Ripgrep.Service).grep({ cwd, pattern: "needle", include: "*.ts", limit: 10 })
         expect(result).toHaveLength(1)
-        expect(result[0]?.entry.path).toBe(RelativePath.make(path.join("src", "match.ts")))
+        expect(result[0]?.entry.path).toBe(RelativePath.make("src/match.ts"))
         expect(result[0]?.submatches[0]?.text).toBe("needle")
       }),
     ),

packages/core/test/fixture/location.ts

@@ -1,6 +1,8 @@
 import { Location } from "@opencode-ai/core/location"
 import { Project } from "@opencode-ai/core/project"
 import { AbsolutePath } from "@opencode-ai/core/schema"
+import { Effect, Layer } from "effect"
+import { tmpdir } from "./tmpdir"
 
 export function location(ref: Location.Ref, input: { projectDirectory?: AbsolutePath; vcs?: Project.Vcs } = {}) {
   return {
@@ -10,3 +12,15 @@ export function location(ref: Location.Ref, input: { projectDirectory?: Absolute
     vcs: input.vcs,
   } satisfies Location.Interface
 }
+
+export const tempLocationLayer = Layer.unwrap(
+  Effect.acquireRelease(
+    Effect.promise(() => tmpdir()),
+    (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
+  ).pipe(
+    Effect.map((tmp) => {
+      const ref = Location.Ref.make({ directory: AbsolutePath.make(tmp.path) })
+      return Layer.succeed(Location.Service, Location.Service.of(location(ref)))
+    }),
+  ),
+)

packages/core/test/integration.test.ts

@@ -4,45 +4,12 @@ import * as TestClock from "effect/testing/TestClock"
 import { Integration } from "@opencode-ai/core/integration"
 import { Credential } from "@opencode-ai/core/credential"
 import { EventV2 } from "@opencode-ai/core/event"
-import { it } from "./lib/effect"
+import { testEffect } from "./lib/effect"
 
-const layer = Integration.locationLayer.pipe(
-  Layer.provide(EventV2.defaultLayer),
-  Layer.provide(
-    Layer.mock(Credential.Service)({
-      create: () => Effect.die("unexpected credential creation"),
-      list: () => Effect.succeed([]),
-    }),
-  ),
+const it = testEffect(
+  Integration.locationLayer.pipe(Layer.provideMerge(Credential.defaultLayer), Layer.provideMerge(EventV2.defaultLayer)),
 )
 
-function connectionLayer(
-  created: Array<{
-    integrationID: Integration.ID
-    label?: string
-    value: Credential.Info
-  }>,
-) {
-  return Integration.locationLayer.pipe(
-    Layer.provideMerge(EventV2.defaultLayer),
-    Layer.provide(
-      Layer.mock(Credential.Service)({
-        create: (input) =>
-          Effect.sync(() => {
-            created.push(input)
-            return new Credential.Stored({
-              id: Credential.ID.create(),
-              integrationID: input.integrationID,
-              label: input.label ?? "default",
-              value: input.value,
-            })
-          }),
-        list: () => Effect.succeed([]),
-      }),
-    ),
-  )
-}
-
 describe("Integration", () => {
   it.effect("registers integrations through the editor", () =>
     Effect.gen(function* () {
@@ -59,7 +26,7 @@ describe("Integration", () => {
 
       yield* Scope.close(scope, Exit.void)
       expect(yield* integrations.get(openai)).toBeUndefined()
-    }).pipe(Effect.provide(layer)),
+    }),
   )
 
   it.effect("reveals the previous registration when an override closes", () =>
@@ -80,7 +47,7 @@ describe("Integration", () => {
       yield* Scope.close(second, Exit.void)
       expect((yield* integrations.get(id))?.name).toBe("OpenAI")
       expect((yield* integrations.list()).map((integration) => integration.id)).toEqual([id])
-    }).pipe(Effect.provide(layer)),
+    }),
   )
 
   it.effect("registers and overrides methods independently", () =>
@@ -128,17 +95,13 @@ describe("Integration", () => {
       yield* Scope.close(second, Exit.void)
       expect((yield* integrations.get(integrationID))?.methods[0]).toMatchObject({ label: "ChatGPT" })
       expect((yield* integrations.get(integrationID))?.methods).toEqual([expect.objectContaining({ id: methodID })])
-    }).pipe(Effect.provide(layer)),
+    }),
   )
 
-  it.effect("connects with a key and stores the credential", () => {
-    const created: Array<{
-      integrationID: Integration.ID
-      label?: string
-      value: Credential.Info
-    }> = []
-    return Effect.gen(function* () {
+  it.effect("connects with a key and stores the credential", () =>
+    Effect.gen(function* () {
       const integrations = yield* Integration.Service
+      const credentials = yield* Credential.Service
       const events = yield* EventV2.Service
       const integrationID = Integration.ID.make("openai")
       yield* integrations.transform((editor) =>
@@ -158,25 +121,21 @@ describe("Integration", () => {
         label: "Work",
       })
 
-      expect(created).toEqual([
-        {
+      expect(yield* credentials.list(integrationID)).toEqual([
+        expect.objectContaining({
           integrationID,
           label: "Work",
           value: new Credential.Key({ type: "key", key: "secret" }),
-        },
+        }),
       ])
       expect((yield* Fiber.join(updated)).length).toBe(1)
-    }).pipe(Effect.provide(connectionLayer(created)))
-  })
+    }),
+  )
 
-  it.effect("completes code OAuth once and stores the credential", () => {
-    const created: Array<{
-      integrationID: Integration.ID
-      label?: string
-      value: Credential.Info
-    }> = []
-    return Effect.gen(function* () {
+  it.effect("completes code OAuth once and stores the credential", () =>
+    Effect.gen(function* () {
       const integrations = yield* Integration.Service
+      const credentials = yield* Credential.Service
       const integrationID = Integration.ID.make("openai")
       const methodID = Integration.MethodID.make("chatgpt")
       yield* integrations.transform((editor) =>
@@ -212,29 +171,27 @@ describe("Integration", () => {
       expect(attempt.mode).toBe("code")
       yield* integrations.attempt.complete({ attemptID: attempt.attemptID, code: "1234" })
 
-      expect(created[0]).toEqual({
-        integrationID,
-        label: "Personal",
-        value: new Credential.OAuth({
-          type: "oauth",
-          methodID,
-          access: "access",
-          refresh: "refresh",
-          expires: 1,
-          metadata: { code: "1234" },
+      expect((yield* credentials.list(integrationID))[0]).toEqual(
+        expect.objectContaining({
+          integrationID,
+          label: "Personal",
+          value: new Credential.OAuth({
+            type: "oauth",
+            methodID,
+            access: "access",
+            refresh: "refresh",
+            expires: 1,
+            metadata: { code: "1234" },
+          }),
         }),
-      })
-    }).pipe(Effect.provide(connectionLayer(created)))
-  })
+      )
+    }),
+  )
 
-  it.effect("keeps code attempts open when the code is missing and closes them on cancel", () => {
-    const created: Array<{
-      integrationID: Integration.ID
-      label?: string
-      value: Credential.Info
-    }> = []
-    return Effect.gen(function* () {
+  it.effect("keeps code attempts open when the code is missing and closes them on cancel", () =>
+    Effect.gen(function* () {
       const integrations = yield* Integration.Service
+      const credentials = yield* Credential.Service
       const integrationID = Integration.ID.make("openai")
       const methodID = Integration.MethodID.make("chatgpt")
       let closed = false
@@ -261,18 +218,14 @@ describe("Integration", () => {
       expect(closed).toBe(false)
       yield* integrations.attempt.cancel(attempt.attemptID)
       expect(closed).toBe(true)
-      expect(created).toEqual([])
-    }).pipe(Effect.provide(connectionLayer(created)))
-  })
+      expect(yield* credentials.list(integrationID)).toEqual([])
+    }),
+  )
 
-  it.effect("completes auto OAuth in the background", () => {
-    const created: Array<{
-      integrationID: Integration.ID
-      label?: string
-      value: Credential.Info
-    }> = []
-    return Effect.gen(function* () {
+  it.effect("completes auto OAuth in the background", () =>
+    Effect.gen(function* () {
       const integrations = yield* Integration.Service
+      const credentials = yield* Credential.Service
       const integrationID = Integration.ID.make("openai")
       const methodID = Integration.MethodID.make("browser")
       yield* integrations.transform((editor) =>
@@ -297,18 +250,14 @@ describe("Integration", () => {
         status: "complete",
         time: attempt.time,
       })
-      expect(created).toHaveLength(1)
-    }).pipe(Effect.provide(connectionLayer(created)))
-  })
+      expect(yield* credentials.list(integrationID)).toHaveLength(1)
+    }),
+  )
 
-  it.effect("expires abandoned OAuth attempts", () => {
-    const created: Array<{
-      integrationID: Integration.ID
-      label?: string
-      value: Credential.Info
-    }> = []
-    return Effect.gen(function* () {
+  it.effect("expires abandoned OAuth attempts", () =>
+    Effect.gen(function* () {
       const integrations = yield* Integration.Service
+      const credentials = yield* Credential.Service
       const integrationID = Integration.ID.make("openai")
       const methodID = Integration.MethodID.make("browser")
       let closed = false
@@ -337,34 +286,12 @@ describe("Integration", () => {
         time: attempt.time,
       })
       expect(closed).toBe(true)
-      expect(created).toEqual([])
-    }).pipe(Effect.provide(connectionLayer(created)))
-  })
+      expect(yield* credentials.list(integrationID)).toEqual([])
+    }),
+  )
 
   it.effect("projects credential and env connections", () => {
     const integrationID = Integration.ID.make("acme")
-    const rows = [
-      {
-        id: Credential.ID.create(),
-        integrationID,
-        label: "Work",
-        value: new Credential.Key({ type: "key", key: "a" }),
-      },
-      {
-        id: Credential.ID.create(),
-        integrationID,
-        label: "Personal",
-        value: new Credential.Key({ type: "key", key: "b" }),
-      },
-    ]
-    const projectionLayer = Integration.locationLayer.pipe(
-      Layer.provide(EventV2.defaultLayer),
-      Layer.provide(
-        Layer.mock(Credential.Service)({
-          list: () => Effect.succeed(rows.map((row) => new Credential.Stored(row))),
-        }),
-      ),
-    )
     return Effect.acquireUseRelease(
       Effect.sync(() => {
         const previous = process.env.INTEGRATION_TEST_ACME_KEY
@@ -375,6 +302,7 @@ describe("Integration", () => {
       () =>
         Effect.gen(function* () {
           const integrations = yield* Integration.Service
+          const credentials = yield* Credential.Service
           yield* integrations.transform((editor) =>
             editor.method.update({
               integrationID,
@@ -384,23 +312,33 @@ describe("Integration", () => {
               },
             }),
           )
+          const work = yield* credentials.create({
+            integrationID,
+            label: "Work",
+            value: new Credential.Key({ type: "key", key: "a" }),
+          })
+          const personal = yield* credentials.create({
+            integrationID,
+            label: "Personal",
+            value: new Credential.Key({ type: "key", key: "b" }),
+          })
 
           // Stored credentials and detected env vars appear as connections.
           expect((yield* integrations.get(integrationID))?.connections).toEqual([
-            { type: "credential", id: rows[0]!.id, label: "Work" },
             {
               type: "credential",
-              id: rows[1]!.id,
+              id: personal.id,
               label: "Personal",
             },
             { type: "env", name: "INTEGRATION_TEST_ACME_KEY" },
           ])
           expect(yield* integrations.connection.forIntegration(integrationID)).toEqual({
             type: "credential",
-            id: rows[1]!.id,
+            id: personal.id,
             label: "Personal",
           })
-        }).pipe(Effect.provide(projectionLayer)),
+          expect(work.id).not.toBe(personal.id)
+        }),
       (previous) =>
         Effect.sync(() => {
           if (previous === undefined) delete process.env.INTEGRATION_TEST_ACME_KEY

packages/core/test/location-filesystem.test.ts

@@ -1,7 +1,7 @@
 import fs from "fs/promises"
 import path from "path"
 import { describe, expect } from "bun:test"
-import { Cause, Effect, Exit, Layer } from "effect"
+import { Effect, Exit, Layer } from "effect"
 import { FileSystem } from "@opencode-ai/core/filesystem"
 import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Location } from "@opencode-ai/core/location"
@@ -31,13 +31,6 @@ const withTmp = <A, E, R>(f: (directory: string) => Effect.Effect<A, E, R>) =>
   ).pipe(Effect.flatMap((tmp) => f(tmp.path)))
 
 describe("FileSystem", () => {
-  const expectFail = (exit: Exit.Exit<unknown, unknown>) => {
-    expect(Exit.isFailure(exit)).toBe(true)
-    if (Exit.isSuccess(exit)) return
-    expect(Cause.hasFails(exit.cause)).toBe(true)
-    expect(Cause.hasDies(exit.cause)).toBe(false)
-  }
-
   it.live("reads text and binary files", () =>
     withTmp((directory) =>
       Effect.gen(function* () {
@@ -67,39 +60,13 @@ describe("FileSystem", () => {
     ),
   )
 
-  it.live("fails for missing paths", () =>
+  it.live("rejects lexical escapes", () =>
     withTmp((directory) =>
       Effect.gen(function* () {
-        const exit = yield* (yield* FileSystem.Service)
-          .read({ path: RelativePath.make("missing.txt") })
+        const result = yield* (yield* FileSystem.Service)
+          .read({ path: RelativePath.make("../outside.txt") })
           .pipe(Effect.exit)
-        expectFail(exit)
-      }).pipe(provide(directory)),
-    ),
-  )
-
-  it.live("fails for wrong path kinds", () =>
-    withTmp((directory) =>
-      Effect.gen(function* () {
-        yield* Effect.promise(() => fs.mkdir(path.join(directory, "src")))
-        yield* Effect.promise(() => fs.writeFile(path.join(directory, "README.md"), "# Test"))
-        const service = yield* FileSystem.Service
-        expectFail(yield* service.read({ path: RelativePath.make("src") }).pipe(Effect.exit))
-        expectFail(yield* service.list({ path: RelativePath.make("README.md") }).pipe(Effect.exit))
-      }).pipe(provide(directory)),
-    ),
-  )
-
-  it.live("fails for lexical and symlink escapes", () =>
-    withTmp((directory) =>
-      Effect.gen(function* () {
-        const outside = path.join(directory, "..", "outside.txt")
-        yield* Effect.promise(() => fs.writeFile(outside, "outside"))
-        yield* Effect.promise(() => fs.symlink(outside, path.join(directory, "linked.txt")))
-        const service = yield* FileSystem.Service
-        expectFail(yield* service.read({ path: RelativePath.make("../outside.txt") }).pipe(Effect.exit))
-        expectFail(yield* service.read({ path: RelativePath.make("linked.txt") }).pipe(Effect.exit))
-        yield* Effect.promise(() => fs.rm(outside))
+        expect(Exit.isFailure(result)).toBe(true)
       }).pipe(provide(directory)),
     ),
   )

packages/core/test/location-layer.test.ts

@@ -1,16 +1,20 @@
 import fs from "fs/promises"
 import path from "path"
 import { describe, expect } from "bun:test"
-import { Deferred, Effect, Equal, Hash, Layer, Schema, Stream } from "effect"
+import { DateTime, Deferred, Effect, Equal, Hash, Layer, Schema, Stream } from "effect"
 import { Tool } from "@opencode-ai/core/public"
 import { define } from "@opencode-ai/plugin/v2/effect"
 import { AgentV2 } from "@opencode-ai/core/agent"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { LocationServiceMap } from "@opencode-ai/core/location-layer"
 import { Location } from "@opencode-ai/core/location"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginBoot } from "@opencode-ai/core/plugin/boot"
+import { ProjectV2 } from "@opencode-ai/core/project"
 import { ProviderV2 } from "@opencode-ai/core/provider"
 import { AbsolutePath } from "@opencode-ai/core/schema"
+import { SessionV2 } from "@opencode-ai/core/session"
+import { SessionRunnerModel } from "@opencode-ai/core/session/runner/model"
 import { tmpdir } from "./fixture/tmpdir"
 import { testEffect } from "./lib/effect"
 import { toolDefinitions } from "./lib/tool"
@@ -36,8 +40,7 @@ const it = testEffect(
         Layer.mergeAll(
           Project.defaultLayer,
           EventV2.defaultLayer,
-          Credential.defaultLayer,
-          Credential.layer.pipe(Layer.provide(Database.layerFromPath(":memory:").pipe(Layer.fresh))),
+          Credential.defaultLayer.pipe(Layer.fresh),
           Npm.defaultLayer,
           ModelsDev.defaultLayer,
           FSUtil.defaultLayer,
@@ -137,6 +140,56 @@ describe("LocationServiceMap", () => {
     ),
   )
 
+  it.live("rejects an unavailable selected model during location model resolution", () =>
+    Effect.acquireRelease(
+      Effect.promise(() => tmpdir()),
+      (dir) => Effect.promise(() => dir[Symbol.asyncDispose]()),
+    ).pipe(
+      Effect.flatMap((dir) =>
+        Effect.gen(function* () {
+          const location = Location.Ref.make({ directory: AbsolutePath.make(dir.path) })
+          yield* Effect.promise(() =>
+            fs.writeFile(
+              path.join(dir.path, "opencode.json"),
+              JSON.stringify({
+                providers: {
+                  unavailable: {
+                    name: "Unavailable",
+                    api: { type: "native", settings: {} },
+                    models: { chat: { disabled: true } },
+                  },
+                },
+              }),
+            ),
+          )
+          const failure = yield* SessionRunnerModel.Service.use((models) =>
+            models.resolve(
+              SessionV2.Info.make({
+                id: SessionV2.ID.make("ses_unavailable_model"),
+                projectID: ProjectV2.ID.global,
+                title: "test",
+                model: {
+                  id: ModelV2.ID.make("chat"),
+                  providerID: ProviderV2.ID.make("unavailable"),
+                },
+                cost: 0,
+                tokens: { input: 0, output: 0, reasoning: 0, cache: { read: 0, write: 0 } },
+                time: { created: DateTime.makeUnsafe(0), updated: DateTime.makeUnsafe(0) },
+                location,
+              }),
+            ),
+          ).pipe(Effect.provide(LocationServiceMap.get(location)), Effect.flip)
+
+          expect(failure).toMatchObject({
+            _tag: "SessionRunnerModel.ModelUnavailableError",
+            providerID: "unavailable",
+            modelID: "chat",
+          })
+        }),
+      ),
+    ),
+  )
+
   it.live("installs public plugins into a location", () =>
     Effect.acquireRelease(
       Effect.promise(() => tmpdir()),

packages/core/test/move-session.test.ts

@@ -21,34 +21,39 @@ import { SessionStore } from "@opencode-ai/core/session/store"
 import { tmpdir } from "./fixture/tmpdir"
 import { testEffect } from "./lib/effect"
 
-const database = Database.layerFromPath(":memory:")
-const events = EventV2.layer.pipe(Layer.provide(database))
-const directories = ProjectDirectories.layer.pipe(Layer.provide(database), Layer.provide(events))
-const projector = SessionProjector.layer.pipe(Layer.provide(database), Layer.provide(events))
 const project = Project.layer.pipe(
-  Layer.provide(database),
+  Layer.provide(Database.defaultLayer),
   Layer.provide(FSUtil.defaultLayer),
   Layer.provide(Git.defaultLayer),
-  Layer.provide(directories),
+  Layer.provide(ProjectDirectories.defaultLayer),
 )
-const store = SessionStore.layer.pipe(Layer.provide(database))
 const sessions = SessionV2.layer.pipe(
-  Layer.provide(database),
-  Layer.provide(events),
+  Layer.provide(Database.defaultLayer),
+  Layer.provide(EventV2.defaultLayer),
   Layer.provide(project),
-  Layer.provide(store),
+  Layer.provide(SessionStore.defaultLayer),
   Layer.provide(SessionExecution.noopLayer),
 )
 const layer = MoveSession.layer.pipe(
-  Layer.provide(database),
+  Layer.provide(Database.defaultLayer),
   Layer.provide(FSUtil.defaultLayer),
   Layer.provide(Git.defaultLayer),
-  Layer.provide(events),
+  Layer.provide(EventV2.defaultLayer),
   Layer.provide(project),
   Layer.provide(sessions),
 )
 const it = testEffect(
-  Layer.mergeAll(layer, database, events, directories, project, projector, store, SessionExecution.noopLayer, sessions),
+  Layer.mergeAll(
+    layer,
+    Database.defaultLayer,
+    EventV2.defaultLayer,
+    ProjectDirectories.defaultLayer,
+    project,
+    SessionProjector.defaultLayer,
+    SessionStore.defaultLayer,
+    SessionExecution.noopLayer,
+    sessions,
+  ),
 )
 
 function abs(input: string) {

packages/core/test/permission.test.ts

@@ -18,29 +18,25 @@ import { eq } from "drizzle-orm"
 import { location } from "./fixture/location"
 import { testEffect } from "./lib/effect"
 
-const database = Database.layerFromPath(":memory:")
 const current = Layer.succeed(
   Location.Service,
   Location.Service.of(location({ directory: AbsolutePath.make("/project") })),
 )
-const events = EventV2.layer.pipe(Layer.provide(database))
-const store = SessionStore.layer.pipe(Layer.provide(database))
 const sessions = SessionV2.layer.pipe(
-  Layer.provide(events),
-  Layer.provide(database),
-  Layer.provide(store),
+  Layer.provide(EventV2.defaultLayer),
+  Layer.provide(Database.defaultLayer),
+  Layer.provide(SessionStore.defaultLayer),
   Layer.provide(Project.defaultLayer),
   Layer.provide(SessionExecution.noopLayer),
 )
-const saved = PermissionSaved.layer.pipe(Layer.provide(database))
 const layer = PermissionV2.locationLayer.pipe(
-  Layer.provideMerge(database),
-  Layer.provideMerge(store),
-  Layer.provideMerge(events),
+  Layer.provideMerge(Database.defaultLayer),
+  Layer.provideMerge(SessionStore.defaultLayer),
+  Layer.provideMerge(EventV2.defaultLayer),
   Layer.provideMerge(current),
   Layer.provideMerge(sessions),
   Layer.provideMerge(SessionExecution.noopLayer),
-  Layer.provideMerge(saved),
+  Layer.provideMerge(PermissionSaved.defaultLayer),
 )
 const it = testEffect(layer)
 

packages/core/test/plugin.test.ts

@@ -46,6 +46,40 @@ describe("PluginV2", () => {
     }),
   )
 
+  it.effect("batches plugin state rebuilds when the registry layer finalizes", () =>
+    Effect.gen(function* () {
+      let finalized = 0
+      const values = State.create({
+        initial: () => ({ values: [] as string[] }),
+        draft: (draft) => ({ add: (value: string) => draft.values.push(value) }),
+        finalize: () => Effect.sync(() => finalized++),
+      })
+      const layerScope = yield* Scope.fork(yield* Scope.Scope)
+      const plugin = Context.get(yield* Layer.buildWithScope(Layer.fresh(plugins), layerScope), PluginV2.Service)
+
+      yield* State.batch(
+        Effect.forEach(
+          ["first", "second"],
+          (id) =>
+            plugin.add({
+              id: PluginV2.ID.make(id),
+              effect: values
+                .transform((editor) => {
+                  editor.add(id)
+                })
+                .pipe(Effect.asVoid),
+            }),
+          { discard: true },
+        ),
+      )
+      finalized = 0
+
+      yield* Scope.close(layerScope, Exit.void)
+      expect(values.get().values).toEqual([])
+      expect(finalized).toBe(1)
+    }),
+  )
+
   it.effect("serializes same-ID additions and leaves one removable attachment", () =>
     Effect.gen(function* () {
       const values = state()

packages/core/test/plugin/fixture.ts

@@ -0,0 +1,48 @@
+import { AgentV2 } from "@opencode-ai/core/agent"
+import { Catalog } from "@opencode-ai/core/catalog"
+import { CommandV2 } from "@opencode-ai/core/command"
+import { Credential } from "@opencode-ai/core/credential"
+import { EventV2 } from "@opencode-ai/core/event"
+import { FileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
+import { Global } from "@opencode-ai/core/global"
+import { Npm } from "@opencode-ai/core/npm"
+import { PluginV2 } from "@opencode-ai/core/plugin"
+import { Reference } from "@opencode-ai/core/reference"
+import { RepositoryCache } from "@opencode-ai/core/repository-cache"
+import { Ripgrep } from "@opencode-ai/core/ripgrep"
+import { SkillV2 } from "@opencode-ai/core/skill"
+import { SkillDiscovery } from "@opencode-ai/core/skill/discovery"
+import { Effect, Layer } from "effect"
+import { tempLocationLayer } from "../fixture/location"
+
+export const PluginTestLayer = Layer.mergeAll(
+  AgentV2.locationLayer,
+  CommandV2.locationLayer,
+  Catalog.locationLayer,
+  FileSystem.locationLayer,
+  PluginV2.locationLayer,
+  Reference.locationLayer,
+  SkillV2.locationLayer,
+).pipe(
+  Layer.provideMerge(
+    Layer.mergeAll(
+      Credential.defaultLayer,
+      EventV2.defaultLayer,
+      FSUtil.defaultLayer,
+      Global.defaultLayer,
+      Layer.succeed(
+        Npm.Service,
+        Npm.Service.of({
+          add: () => Effect.succeed({ directory: "", entrypoint: undefined }),
+          install: () => Effect.void,
+          which: () => Effect.succeed(undefined),
+        }),
+      ),
+      RepositoryCache.defaultLayer,
+      SkillDiscovery.defaultLayer,
+      Ripgrep.defaultLayer,
+      tempLocationLayer,
+    ),
+  ),
+)

packages/core/test/plugin/models-dev.test.ts

@@ -24,11 +24,7 @@ const locationLayer = Layer.succeed(
 )
 const plugins = PluginV2.layer.pipe(Layer.provide(events))
 const policy = Policy.layer.pipe(Layer.provide(locationLayer))
-const connections = Credential.layer.pipe(
-  Layer.fresh,
-  Layer.provide(Database.layerFromPath(":memory:").pipe(Layer.fresh)),
-  Layer.provide(events),
-)
+const connections = Credential.defaultLayer.pipe(Layer.fresh)
 const integrations = Integration.locationLayer.pipe(Layer.provide(events), Layer.provide(connections))
 const catalog = Catalog.layer.pipe(
   Layer.provide(Layer.mergeAll(events, locationLayer, plugins, policy, connections, integrations)),

packages/core/test/plugin/provider-alibaba.test.ts

@@ -3,17 +3,35 @@ import { createAlibaba } from "@ai-sdk/alibaba"
 import { Effect } from "effect"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { AlibabaPlugin } from "@opencode-ai/core/plugin/provider/alibaba"
-import { addPlugin, it, model } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: AlibabaPlugin.id, effect: AlibabaPlugin.effect(host) })
+})
 
 describe("AlibabaPlugin", () => {
   it.effect("creates an Alibaba SDK for @ai-sdk/alibaba", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, AlibabaPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("alibaba", "qwen"), package: "@ai-sdk/alibaba", options: { name: "alibaba" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("alibaba"), ModelV2.ID.make("qwen")),
+            api: { id: ModelV2.ID.make("qwen"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/alibaba",
+          options: { name: "alibaba" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -23,10 +41,17 @@ describe("AlibabaPlugin", () => {
   it.effect("ignores non-Alibaba SDK packages", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, AlibabaPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("alibaba", "qwen"), package: "@ai-sdk/openai-compatible", options: { name: "alibaba" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("alibaba"), ModelV2.ID.make("qwen")),
+            api: { id: ModelV2.ID.make("qwen"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/openai-compatible",
+          options: { name: "alibaba" },
+        },
         {},
       )
       expect(result.sdk).toBeUndefined()
@@ -36,11 +61,14 @@ describe("AlibabaPlugin", () => {
   it.effect("matches the old bundled Alibaba SDK provider naming", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, AlibabaPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-alibaba", "qwen"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-alibaba"), ModelV2.ID.make("qwen")),
+            api: { id: ModelV2.ID.make("qwen"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/alibaba",
           options: { name: "custom-alibaba", apiKey: "test" },
         },
@@ -56,8 +84,11 @@ describe("AlibabaPlugin", () => {
   it.effect("uses the old default languageModel(api.id) behavior", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, AlibabaPlugin)
-      const item = model("alibaba", "alias", { api: { id: ModelV2.ID.make("qwen-plus") } })
+      yield* addPlugin()
+      const item = new ModelV2.Info({
+        ...ModelV2.Info.empty(ProviderV2.ID.make("alibaba"), ModelV2.ID.make("alias")),
+        api: { id: ModelV2.ID.make("qwen-plus"), type: "aisdk", package: "test-provider" },
+      })
       const result = yield* plugin.trigger("aisdk.sdk", { model: item, package: "@ai-sdk/alibaba", options: {} }, {})
       const language = result.sdk?.languageModel(item.api.id)
       expect(language?.modelId).toBe("qwen-plus")

packages/core/test/plugin/provider-amazon-bedrock.test.ts

@@ -1,10 +1,61 @@
 import { describe, expect } from "bun:test"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { AmazonBedrockPlugin } from "@opencode-ai/core/plugin/provider/amazon-bedrock"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, fakeSelectorSdk, it, model, provider, required, withEnv } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: AmazonBedrockPlugin.id, effect: AmazonBedrockPlugin.effect(host) })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, fx: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    fx,
+    (previous) =>
+      Effect.sync(() => {
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        })
+      }),
+  )
+}
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
 
 function bedrockBaseURL(sdk: unknown, modelID = "anthropic.claude-sonnet-4-5") {
   const language = (sdk as { languageModel: (id: string) => unknown }).languageModel(modelID)
@@ -28,11 +79,10 @@ function openAIUrl(language: unknown, path: string, modelId: string) {
 describe("AmazonBedrockPlugin", () => {
   it.effect("moves endpoint option to api URL", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, AmazonBedrockPlugin)
       yield* catalog.transform((catalog) => {
-        const bedrock = provider("amazon-bedrock", {
+        const bedrock = new ProviderV2.Info({
+          ...ProviderV2.Info.empty(ProviderV2.ID.amazonBedrock),
           api: { type: "aisdk", package: "@ai-sdk/amazon-bedrock" },
           request: {
             headers: {},
@@ -44,6 +94,7 @@ describe("AmazonBedrockPlugin", () => {
           item.request = bedrock.request
         })
       })
+      yield* addPlugin()
       const result = required(yield* catalog.provider.get(ProviderV2.ID.amazonBedrock))
       expect(result.api).toEqual({
         type: "aisdk",
@@ -58,11 +109,14 @@ describe("AmazonBedrockPlugin", () => {
     withEnv({ AWS_BEARER_TOKEN_BEDROCK: undefined, AWS_PROFILE: undefined, AWS_ACCESS_KEY_ID: undefined }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, AmazonBedrockPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+              api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/amazon-bedrock",
             options: {
               name: "amazon-bedrock",
@@ -83,11 +137,14 @@ describe("AmazonBedrockPlugin", () => {
     withEnv({ AWS_BEARER_TOKEN_BEDROCK: undefined, AWS_PROFILE: undefined, AWS_ACCESS_KEY_ID: undefined }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, AmazonBedrockPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+              api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/amazon-bedrock",
             options: {
               name: "amazon-bedrock",
@@ -117,11 +174,18 @@ describe("AmazonBedrockPlugin", () => {
       () =>
         Effect.gen(function* () {
           const plugin = yield* PluginV2.Service
-          yield* addPlugin(plugin, AmazonBedrockPlugin)
+          yield* addPlugin()
           const result = yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+                api: {
+                  id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"),
+                  type: "aisdk",
+                  package: "test-provider",
+                },
+              }),
               package: "@ai-sdk/amazon-bedrock",
               options: { name: "amazon-bedrock" },
             },
@@ -137,11 +201,14 @@ describe("AmazonBedrockPlugin", () => {
     withEnv({ AWS_BEARER_TOKEN_BEDROCK: "token", AWS_REGION: "us-east-1" }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, AmazonBedrockPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+              api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/amazon-bedrock",
             options: { name: "amazon-bedrock", region: "eu-west-1" },
           },
@@ -156,11 +223,14 @@ describe("AmazonBedrockPlugin", () => {
     withEnv({ AWS_BEARER_TOKEN_BEDROCK: "token", AWS_REGION: "eu-west-1" }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, AmazonBedrockPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+              api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/amazon-bedrock",
             options: { name: "amazon-bedrock" },
           },
@@ -175,11 +245,14 @@ describe("AmazonBedrockPlugin", () => {
     withEnv({ AWS_BEARER_TOKEN_BEDROCK: "token", AWS_REGION: undefined }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, AmazonBedrockPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+              api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/amazon-bedrock",
             options: { name: "amazon-bedrock" },
           },
@@ -195,11 +268,14 @@ describe("AmazonBedrockPlugin", () => {
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
         const headers: Array<string | null> = []
-        yield* addPlugin(plugin, AmazonBedrockPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+              api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/amazon-bedrock",
             options: {
               name: "amazon-bedrock",
@@ -224,11 +300,14 @@ describe("AmazonBedrockPlugin", () => {
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
         const headers: Array<string | null> = []
-        yield* addPlugin(plugin, AmazonBedrockPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+              api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/amazon-bedrock",
             options: {
               name: "amazon-bedrock",
@@ -252,12 +331,17 @@ describe("AmazonBedrockPlugin", () => {
     withEnv({ AWS_BEARER_TOKEN_BEDROCK: undefined, AWS_PROFILE: undefined, AWS_ACCESS_KEY_ID: undefined }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, AmazonBedrockPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("amazon-bedrock", "openai.gpt-5.5", {
-              api: { type: "aisdk", package: "@ai-sdk/amazon-bedrock/mantle" },
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("openai.gpt-5.5")),
+              api: {
+                id: ModelV2.ID.make("openai.gpt-5.5"),
+                type: "aisdk",
+                package: "@ai-sdk/amazon-bedrock/mantle",
+              },
             }),
             package: "@ai-sdk/amazon-bedrock/mantle",
             options: {
@@ -281,12 +365,17 @@ describe("AmazonBedrockPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, AmazonBedrockPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("amazon-bedrock", "openai.gpt-5.5", {
-            api: { type: "aisdk", package: "@ai-sdk/amazon-bedrock/mantle" },
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("openai.gpt-5.5")),
+            api: {
+              id: ModelV2.ID.make("openai.gpt-5.5"),
+              type: "aisdk",
+              package: "@ai-sdk/amazon-bedrock/mantle",
+            },
           }),
           sdk: fakeSelectorSdk(calls),
           options: { baseURL: "https://bedrock-mantle.us-east-2.api.aws/openai/v1", region: "us-east-2" },
@@ -296,8 +385,13 @@ describe("AmazonBedrockPlugin", () => {
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("amazon-bedrock", "openai.gpt-oss-safeguard-120b", {
-            api: { type: "aisdk", package: "@ai-sdk/amazon-bedrock/mantle" },
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("openai.gpt-oss-safeguard-120b")),
+            api: {
+              id: ModelV2.ID.make("openai.gpt-oss-safeguard-120b"),
+              type: "aisdk",
+              package: "@ai-sdk/amazon-bedrock/mantle",
+            },
           }),
           sdk: fakeSelectorSdk(calls),
           options: { region: "us-east-1" },
@@ -311,12 +405,17 @@ describe("AmazonBedrockPlugin", () => {
   it.effect("ignores other Bedrock provider subpaths", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, AmazonBedrockPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5", {
-            api: { type: "aisdk", package: "@ai-sdk/amazon-bedrock/anthropic" },
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+            api: {
+              id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"),
+              type: "aisdk",
+              package: "@ai-sdk/amazon-bedrock/anthropic",
+            },
           }),
           package: "@ai-sdk/amazon-bedrock/anthropic",
           options: { name: "amazon-bedrock" },
@@ -340,11 +439,18 @@ describe("AmazonBedrockPlugin", () => {
         Effect.gen(function* () {
           const plugin = yield* PluginV2.Service
           const headers: Array<string | null> = []
-          yield* addPlugin(plugin, AmazonBedrockPlugin)
+          yield* addPlugin()
           const result = yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+                api: {
+                  id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"),
+                  type: "aisdk",
+                  package: "test-provider",
+                },
+              }),
               package: "@ai-sdk/amazon-bedrock",
               options: {
                 name: "amazon-bedrock",
@@ -371,11 +477,14 @@ describe("AmazonBedrockPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, AmazonBedrockPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+            api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
           options: {},
         },
@@ -384,7 +493,10 @@ describe("AmazonBedrockPlugin", () => {
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+            api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
           options: { region: "eu-west-1" },
         },
@@ -393,7 +505,14 @@ describe("AmazonBedrockPlugin", () => {
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("amazon-bedrock", "global.anthropic.claude-sonnet-4-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("global.anthropic.claude-sonnet-4-5")),
+            api: {
+              id: ModelV2.ID.make("global.anthropic.claude-sonnet-4-5"),
+              type: "aisdk",
+              package: "test-provider",
+            },
+          }),
           sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
           options: { region: "eu-west-1" },
         },
@@ -402,7 +521,10 @@ describe("AmazonBedrockPlugin", () => {
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+            api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
           options: { region: "ap-northeast-1" },
         },
@@ -411,7 +533,10 @@ describe("AmazonBedrockPlugin", () => {
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+            api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
           options: { region: "ap-southeast-2" },
         },
@@ -432,11 +557,14 @@ describe("AmazonBedrockPlugin", () => {
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
         const calls: string[] = []
-        yield* addPlugin(plugin, AmazonBedrockPlugin)
+        yield* addPlugin()
         yield* plugin.trigger(
           "aisdk.language",
           {
-            model: model("amazon-bedrock", "anthropic.claude-sonnet-4-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+              api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+            }),
             sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
             options: {},
           },
@@ -517,12 +645,15 @@ describe("AmazonBedrockPlugin", () => {
           expected: "au.anthropic.claude-sonnet-4-5",
         },
       ]
-      yield* addPlugin(plugin, AmazonBedrockPlugin)
+      yield* addPlugin()
       for (const item of cases) {
         yield* plugin.trigger(
           "aisdk.language",
           {
-            model: model("amazon-bedrock", item.modelID),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.amazonBedrock, ModelV2.ID.make(item.modelID)),
+              api: { id: ModelV2.ID.make(item.modelID), type: "aisdk", package: "test-provider" },
+            }),
             sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
             options: { region: item.region },
           },
@@ -537,11 +668,14 @@ describe("AmazonBedrockPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, AmazonBedrockPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("openai", "anthropic.claude-sonnet-4-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.openai, ModelV2.ID.make("anthropic.claude-sonnet-4-5")),
+            api: { id: ModelV2.ID.make("anthropic.claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
           options: { region: "eu-west-1" },
         },

packages/core/test/plugin/provider-anthropic.test.ts

@@ -1,19 +1,34 @@
 import { describe, expect } from "bun:test"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { AnthropicPlugin } from "@opencode-ai/core/plugin/provider/anthropic"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, it, model, provider, required } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: AnthropicPlugin.id, effect: AnthropicPlugin.effect(host) })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
 
 describe("AnthropicPlugin", () => {
   it.effect("applies legacy beta headers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, AnthropicPlugin)
       yield* catalog.transform((catalog) => {
-        const item = provider("anthropic", {
+        const item = new ProviderV2.Info({
+          ...ProviderV2.Info.empty(ProviderV2.ID.anthropic),
           api: { type: "aisdk", package: "@ai-sdk/anthropic" },
           request: { headers: { Existing: "1" }, body: {} },
         })
@@ -22,6 +37,7 @@ describe("AnthropicPlugin", () => {
           draft.request = item.request
         })
       })
+      yield* addPlugin()
       expect(required(yield* catalog.provider.get(ProviderV2.ID.anthropic)).request.headers["anthropic-beta"]).toBe(
         "interleaved-thinking-2025-05-14,fine-grained-tool-streaming-2025-05-14",
       )
@@ -31,10 +47,9 @@ describe("AnthropicPlugin", () => {
 
   it.effect("ignores non-Anthropic providers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, AnthropicPlugin)
-      yield* catalog.transform((catalog) => catalog.provider.update(provider("openai").id, () => {}))
+      yield* catalog.transform((catalog) => catalog.provider.update(ProviderV2.ID.openai, () => {}))
+      yield* addPlugin()
       expect(
         required(yield* catalog.provider.get(ProviderV2.ID.openai)).request.headers["anthropic-beta"],
       ).toBeUndefined()
@@ -44,54 +59,40 @@ describe("AnthropicPlugin", () => {
   it.effect("creates Anthropic SDKs with the model provider ID as the SDK name", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      const providers: string[] = []
-      yield* addPlugin(plugin, AnthropicPlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("anthropic-sdk-inspector"),
-        effect: Effect.succeed({
-          "aisdk.sdk": (evt) =>
-            Effect.sync(() => {
-              providers.push(evt.sdk.languageModel("claude-sonnet-4-5").provider)
-            }),
-        }),
-      })
-      yield* plugin.trigger(
+      yield* addPlugin()
+      const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-anthropic", "claude-sonnet-4-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-anthropic"), ModelV2.ID.make("claude-sonnet-4-5")),
+            api: { id: ModelV2.ID.make("claude-sonnet-4-5"), type: "aisdk", package: "@ai-sdk/anthropic" },
+          }),
           package: "@ai-sdk/anthropic",
           options: { name: "custom-anthropic", apiKey: "test" },
         },
         {},
       )
-      expect(providers).toEqual(["custom-anthropic"])
+      expect(result.sdk.languageModel("claude-sonnet-4-5").provider).toBe("custom-anthropic")
     }),
   )
 
   it.effect("uses the Anthropic provider ID as the SDK name for the bundled Anthropic provider", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      const providers: string[] = []
-      yield* addPlugin(plugin, AnthropicPlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("anthropic-sdk-inspector"),
-        effect: Effect.succeed({
-          "aisdk.sdk": (evt) =>
-            Effect.sync(() => {
-              providers.push(evt.sdk.languageModel("claude-sonnet-4-5").provider)
-            }),
-        }),
-      })
-      yield* plugin.trigger(
+      yield* addPlugin()
+      const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("anthropic", "claude-sonnet-4-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.anthropic, ModelV2.ID.make("claude-sonnet-4-5")),
+            api: { id: ModelV2.ID.make("claude-sonnet-4-5"), type: "aisdk", package: "@ai-sdk/anthropic" },
+          }),
           package: "@ai-sdk/anthropic",
           options: { name: "anthropic", apiKey: "test" },
         },
         {},
       )
-      expect(providers).toEqual(["anthropic"])
+      expect(result.sdk.languageModel("claude-sonnet-4-5").provider).toBe("anthropic")
     }),
   )
 })

packages/core/test/plugin/provider-azure-cognitive-services.test.ts

@@ -1,23 +1,73 @@
 import { describe, expect } from "bun:test"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { AzureCognitiveServicesPlugin } from "@opencode-ai/core/plugin/provider/azure"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, fakeSelectorSdk, it, model, provider, required, withEnv } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: AzureCognitiveServicesPlugin.id, effect: AzureCognitiveServicesPlugin.effect(host) })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, fx: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    fx,
+    (previous) =>
+      Effect.sync(() => {
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        })
+      }),
+  )
+}
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
 
 describe("AzureCognitiveServicesPlugin", () => {
   it.effect("maps the resource env var to the Azure SDK baseURL", () =>
     withEnv({ AZURE_COGNITIVE_SERVICES_RESOURCE_NAME: "cognitive" }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
-        yield* addPlugin(plugin, AzureCognitiveServicesPlugin)
         yield* catalog.transform((catalog) => {
           catalog.provider.update(ProviderV2.ID.make("azure-cognitive-services"), (item) => {
             item.api = { type: "aisdk", package: "@ai-sdk/openai-compatible" }
           })
         })
+        yield* addPlugin()
         const result = required(yield* catalog.provider.get(ProviderV2.ID.make("azure-cognitive-services")))
         expect(result.api).toEqual({
           type: "aisdk",
@@ -33,14 +83,16 @@ describe("AzureCognitiveServicesPlugin", () => {
   it.effect("leaves baseURL unset without resource env and ignores other providers", () =>
     withEnv({ AZURE_COGNITIVE_SERVICES_RESOURCE_NAME: undefined }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
-        yield* addPlugin(plugin, AzureCognitiveServicesPlugin)
         yield* catalog.transform((catalog) => {
-          const azure = provider("azure-cognitive-services", {
+          const azure = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.make("azure-cognitive-services")),
             api: { type: "aisdk", package: "@ai-sdk/openai-compatible" },
           })
-          const openai = provider("openai")
+          const openai = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.openai),
+            api: { type: "aisdk", package: "test-provider" },
+          })
           catalog.provider.update(azure.id, (item) => {
             item.api = azure.api
           })
@@ -48,6 +100,7 @@ describe("AzureCognitiveServicesPlugin", () => {
             item.api = openai.api
           })
         })
+        yield* addPlugin()
         const azure = required(yield* catalog.provider.get(ProviderV2.ID.make("azure-cognitive-services")))
         const openai = required(yield* catalog.provider.get(ProviderV2.ID.openai))
         expect(azure.request.body.baseURL).toBeUndefined()
@@ -62,11 +115,14 @@ describe("AzureCognitiveServicesPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, AzureCognitiveServicesPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("azure-cognitive-services", "deployment"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("azure-cognitive-services"), ModelV2.ID.make("deployment")),
+            api: { id: ModelV2.ID.make("deployment"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: fakeSelectorSdk(calls),
           options: { useCompletionUrls: true },
         },
@@ -80,15 +136,29 @@ describe("AzureCognitiveServicesPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, AzureCognitiveServicesPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
-        { model: model("azure-cognitive-services", "deployment"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("azure-cognitive-services"), ModelV2.ID.make("deployment")),
+            api: { id: ModelV2.ID.make("deployment"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       const ignored = yield* plugin.trigger(
         "aisdk.language",
-        { model: model("openai", "deployment"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.openai, ModelV2.ID.make("deployment")),
+            api: { id: ModelV2.ID.make("deployment"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       expect(calls).toEqual(["responses:deployment"])
@@ -101,11 +171,17 @@ describe("AzureCognitiveServicesPlugin", () => {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
       const sdk = fakeSelectorSdk(calls)
-      yield* addPlugin(plugin, AzureCognitiveServicesPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("azure-cognitive-services", "messages-deployment"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(
+              ProviderV2.ID.make("azure-cognitive-services"),
+              ModelV2.ID.make("messages-deployment"),
+            ),
+            api: { id: ModelV2.ID.make("messages-deployment"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { messages: sdk.messages, chat: sdk.chat, languageModel: sdk.languageModel },
           options: {},
         },
@@ -114,7 +190,10 @@ describe("AzureCognitiveServicesPlugin", () => {
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("azure-cognitive-services", "chat-deployment"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("azure-cognitive-services"), ModelV2.ID.make("chat-deployment")),
+            api: { id: ModelV2.ID.make("chat-deployment"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { chat: sdk.chat, languageModel: sdk.languageModel },
           options: {},
         },
@@ -123,7 +202,13 @@ describe("AzureCognitiveServicesPlugin", () => {
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("azure-cognitive-services", "language-deployment"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(
+              ProviderV2.ID.make("azure-cognitive-services"),
+              ModelV2.ID.make("language-deployment"),
+            ),
+            api: { id: ModelV2.ID.make("language-deployment"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { languageModel: sdk.languageModel },
           options: {},
         },

packages/core/test/plugin/provider-azure.test.ts

@@ -1,23 +1,73 @@
 import { describe, expect } from "bun:test"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { AzurePlugin } from "@opencode-ai/core/plugin/provider/azure"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, fakeSelectorSdk, it, model, provider, required, withEnv } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: AzurePlugin.id, effect: AzurePlugin.effect(host) })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, fx: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    fx,
+    (previous) =>
+      Effect.sync(() => {
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        })
+      }),
+  )
+}
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
 
 describe("AzurePlugin", () => {
   it.effect("resolves resourceName from env", () =>
     withEnv({ AZURE_RESOURCE_NAME: "from-env" }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
         yield* catalog.transform((catalog) => {
           catalog.provider.update(ProviderV2.ID.azure, (item) => {
             item.api = { type: "aisdk", package: "@ai-sdk/azure" }
           })
         })
-        yield* addPlugin(plugin, AzurePlugin)
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.azure)).request.body.resourceName).toBe("from-env")
       }),
     ),
@@ -26,10 +76,10 @@ describe("AzurePlugin", () => {
   it.effect("keeps explicit resourceName over env and ignores other providers", () =>
     withEnv({ AZURE_RESOURCE_NAME: "from-env" }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
         yield* catalog.transform((catalog) => {
-          const azure = provider("azure", {
+          const azure = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.azure),
             api: { type: "aisdk", package: "@ai-sdk/azure" },
             request: { headers: {}, body: { resourceName: "from-config" } },
           })
@@ -39,7 +89,7 @@ describe("AzurePlugin", () => {
           })
           catalog.provider.update(ProviderV2.ID.openai, () => {})
         })
-        yield* addPlugin(plugin, AzurePlugin)
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.azure)).request.body.resourceName).toBe("from-config")
         expect(required(yield* catalog.provider.get(ProviderV2.ID.openai)).request.body.resourceName).toBeUndefined()
       }),
@@ -49,10 +99,10 @@ describe("AzurePlugin", () => {
   it.effect("falls back to env when configured resourceName is blank", () =>
     withEnv({ AZURE_RESOURCE_NAME: "from-env" }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
         yield* catalog.transform((catalog) => {
-          const azure = provider("azure", {
+          const azure = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.azure),
             api: { type: "aisdk", package: "@ai-sdk/azure" },
             request: { headers: {}, body: { resourceName: "" } },
           })
@@ -61,7 +111,7 @@ describe("AzurePlugin", () => {
             item.request = azure.request
           })
         })
-        yield* addPlugin(plugin, AzurePlugin)
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.azure)).request.body.resourceName).toBe("from-env")
       }),
     ),
@@ -70,10 +120,10 @@ describe("AzurePlugin", () => {
   it.effect("falls back to env when configured resourceName is whitespace", () =>
     withEnv({ AZURE_RESOURCE_NAME: "from-env" }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
         yield* catalog.transform((catalog) => {
-          const azure = provider("azure", {
+          const azure = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.azure),
             api: { type: "aisdk", package: "@ai-sdk/azure" },
             request: { headers: {}, body: { resourceName: "   " } },
           })
@@ -82,7 +132,7 @@ describe("AzurePlugin", () => {
             item.request = azure.request
           })
         })
-        yield* addPlugin(plugin, AzurePlugin)
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.azure)).request.body.resourceName).toBe("from-env")
       }),
     ),
@@ -92,11 +142,14 @@ describe("AzurePlugin", () => {
     withEnv({ AZURE_RESOURCE_NAME: undefined }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, AzurePlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("azure", "deployment"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.azure, ModelV2.ID.make("deployment")),
+              api: { id: ModelV2.ID.make("deployment"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/azure",
             options: { name: "azure", baseURL: "https://proxy.example.com/openai" },
           },
@@ -111,11 +164,18 @@ describe("AzurePlugin", () => {
     withEnv({ AZURE_RESOURCE_NAME: undefined }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, AzurePlugin)
+        yield* addPlugin()
         const exit = yield* plugin
           .trigger(
             "aisdk.sdk",
-            { model: model("azure", "deployment"), package: "@ai-sdk/azure", options: { name: "azure" } },
+            {
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.azure, ModelV2.ID.make("deployment")),
+                api: { id: ModelV2.ID.make("deployment"), type: "aisdk", package: "test-provider" },
+              }),
+              package: "@ai-sdk/azure",
+              options: { name: "azure" },
+            },
             {},
           )
           .pipe(Effect.exit)
@@ -128,10 +188,17 @@ describe("AzurePlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, AzurePlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
-        { model: model("azure", "deployment"), sdk: fakeSelectorSdk(calls), options: { useCompletionUrls: true } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.azure, ModelV2.ID.make("deployment")),
+            api: { id: ModelV2.ID.make("deployment"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: { useCompletionUrls: true },
+        },
         {},
       )
       expect(calls).toEqual(["chat:deployment"])
@@ -142,10 +209,17 @@ describe("AzurePlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, AzurePlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
-        { model: model("azure", "deployment"), sdk: fakeSelectorSdk(calls), options: { useCompletionUrls: true } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.azure, ModelV2.ID.make("deployment")),
+            api: { id: ModelV2.ID.make("deployment"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: { useCompletionUrls: true },
+        },
         {},
       )
       expect(calls).toEqual(["chat:deployment"])
@@ -156,11 +230,13 @@ describe("AzurePlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, AzurePlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("azure", "deployment", {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.azure, ModelV2.ID.make("deployment")),
+            api: { id: ModelV2.ID.make("deployment"), type: "aisdk", package: "test-provider" },
             request: { headers: {}, body: { useCompletionUrls: true } },
           }),
           sdk: fakeSelectorSdk(calls),
@@ -176,15 +252,29 @@ describe("AzurePlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, AzurePlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
-        { model: model("azure", "deployment"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.azure, ModelV2.ID.make("deployment")),
+            api: { id: ModelV2.ID.make("deployment"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       const ignored = yield* plugin.trigger(
         "aisdk.language",
-        { model: model("openai", "deployment"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.openai, ModelV2.ID.make("deployment")),
+            api: { id: ModelV2.ID.make("deployment"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       expect(calls).toEqual(["responses:deployment"])
@@ -200,11 +290,14 @@ describe("AzurePlugin", () => {
         calls.push(`${method}:${id}`)
         return { modelId: id, provider: method, specificationVersion: "v3" }
       }
-      yield* addPlugin(plugin, AzurePlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("azure", "messages-deployment"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.azure, ModelV2.ID.make("messages-deployment")),
+            api: { id: ModelV2.ID.make("messages-deployment"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { messages: make("messages"), chat: make("chat"), languageModel: make("languageModel") },
           options: {},
         },
@@ -212,7 +305,14 @@ describe("AzurePlugin", () => {
       )
       yield* plugin.trigger(
         "aisdk.language",
-        { model: model("azure", "language-deployment"), sdk: { languageModel: make("languageModel") }, options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.azure, ModelV2.ID.make("language-deployment")),
+            api: { id: ModelV2.ID.make("language-deployment"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: { languageModel: make("languageModel") },
+          options: {},
+        },
         {},
       )
       expect(calls).toEqual(["messages:messages-deployment", "languageModel:language-deployment"])

packages/core/test/plugin/provider-cerebras.test.ts

@@ -1,12 +1,22 @@
 import { describe, expect, mock } from "bun:test"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { CerebrasPlugin } from "@opencode-ai/core/plugin/provider/cerebras"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, it, model, required } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
 
 const cerebrasOptions: Record<string, unknown>[] = []
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: CerebrasPlugin.id, effect: CerebrasPlugin.effect(host) })
+})
 
 void mock.module("@ai-sdk/cerebras", () => ({
   createCerebras: (options: Record<string, unknown>) => {
@@ -21,16 +31,15 @@ void mock.module("@ai-sdk/cerebras", () => ({
 describe("CerebrasPlugin", () => {
   it.effect("applies the legacy integration header", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, CerebrasPlugin)
       yield* catalog.transform((catalog) => {
         catalog.provider.update(ProviderV2.ID.make("cerebras"), (item) => {
           item.api = { type: "aisdk", package: "@ai-sdk/cerebras" }
           item.request.headers.Existing = "1"
         })
       })
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("cerebras"))).request.headers).toEqual({
+      yield* addPlugin()
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("cerebras")))?.request.headers).toEqual({
         Existing: "1",
         "X-Cerebras-3rd-Party-Integration": "opencode",
       })
@@ -39,11 +48,10 @@ describe("CerebrasPlugin", () => {
 
   it.effect("ignores non-Cerebras providers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, CerebrasPlugin)
       yield* catalog.transform((catalog) => catalog.provider.update(ProviderV2.ID.make("groq"), () => {}))
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("groq"))).request.headers).toEqual({})
+      yield* addPlugin()
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("groq")))?.request.headers).toEqual({})
     }),
   )
 
@@ -51,11 +59,21 @@ describe("CerebrasPlugin", () => {
     Effect.gen(function* () {
       cerebrasOptions.length = 0
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, CerebrasPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-cerebras", "llama-4-scout-17b-16e-instruct"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(
+              ProviderV2.ID.make("custom-cerebras"),
+              ModelV2.ID.make("llama-4-scout-17b-16e-instruct"),
+            ),
+            api: {
+              id: ModelV2.ID.make("llama-4-scout-17b-16e-instruct"),
+              type: "aisdk",
+              package: "test-provider",
+            },
+          }),
           package: "@ai-sdk/cerebras",
           options: { name: "custom-cerebras", apiKey: "test" },
         },
@@ -70,11 +88,21 @@ describe("CerebrasPlugin", () => {
     Effect.gen(function* () {
       cerebrasOptions.length = 0
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, CerebrasPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-cerebras", "llama-4-scout-17b-16e-instruct"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(
+              ProviderV2.ID.make("custom-cerebras"),
+              ModelV2.ID.make("llama-4-scout-17b-16e-instruct"),
+            ),
+            api: {
+              id: ModelV2.ID.make("llama-4-scout-17b-16e-instruct"),
+              type: "aisdk",
+              package: "test-provider",
+            },
+          }),
           package: "@ai-sdk/cerebras",
           options: { name: "configured-cerebras", apiKey: "test" },
         },
@@ -88,11 +116,21 @@ describe("CerebrasPlugin", () => {
     Effect.gen(function* () {
       cerebrasOptions.length = 0
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, CerebrasPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-cerebras", "llama-4-scout-17b-16e-instruct"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(
+              ProviderV2.ID.make("custom-cerebras"),
+              ModelV2.ID.make("llama-4-scout-17b-16e-instruct"),
+            ),
+            api: {
+              id: ModelV2.ID.make("llama-4-scout-17b-16e-instruct"),
+              type: "aisdk",
+              package: "test-provider",
+            },
+          }),
           package: "@ai-sdk/groq",
           options: { name: "custom-cerebras", apiKey: "test" },
         },

packages/core/test/plugin/provider-cloudflare-ai-gateway.test.ts

@@ -1,8 +1,41 @@
 import { describe, expect, mock } from "bun:test"
 import { Effect } from "effect"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { CloudflareAIGatewayPlugin } from "@opencode-ai/core/plugin/provider/cloudflare-ai-gateway"
-import { addPlugin, it, model, withEnv } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: CloudflareAIGatewayPlugin.id, effect: CloudflareAIGatewayPlugin.effect(host) })
+})
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, fx: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    fx,
+    (previous) =>
+      Effect.sync(() => {
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        })
+      }),
+  )
+}
 
 const aiGatewayCalls: Record<string, unknown>[] = []
 const unifiedCalls: string[] = []
@@ -78,11 +111,14 @@ describe("CloudflareAIGatewayPlugin", () => {
       () =>
         Effect.gen(function* () {
           const plugin = yield* PluginV2.Service
-          yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+          yield* addPlugin()
           const result = yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("cloudflare-ai-gateway", "openai/gpt-5"),
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-ai-gateway"), ModelV2.ID.make("openai/gpt-5")),
+                api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+              }),
               package: "ai-gateway-provider",
               options: { name: "cloudflare-ai-gateway" },
             },
@@ -98,12 +134,15 @@ describe("CloudflareAIGatewayPlugin", () => {
       Effect.gen(function* () {
         resetCalls()
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+        yield* addPlugin()
 
         yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-ai-gateway", "openai/gpt-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-ai-gateway"), ModelV2.ID.make("openai/gpt-5")),
+              api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "ai-gateway-provider",
             options: {
               name: "cloudflare-ai-gateway",
@@ -142,12 +181,15 @@ describe("CloudflareAIGatewayPlugin", () => {
       Effect.gen(function* () {
         resetCalls()
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+        yield* addPlugin()
 
         yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-ai-gateway", "openai/gpt-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-ai-gateway"), ModelV2.ID.make("openai/gpt-5")),
+              api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "ai-gateway-provider",
             options: {
               name: "cloudflare-ai-gateway",
@@ -171,12 +213,15 @@ describe("CloudflareAIGatewayPlugin", () => {
       Effect.gen(function* () {
         resetCalls()
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+        yield* addPlugin()
 
         yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-ai-gateway", "openai/gpt-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-ai-gateway"), ModelV2.ID.make("openai/gpt-5")),
+              api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "ai-gateway-provider",
             options: {
               name: "cloudflare-ai-gateway",
@@ -208,12 +253,15 @@ describe("CloudflareAIGatewayPlugin", () => {
         Effect.gen(function* () {
           resetCalls()
           const plugin = yield* PluginV2.Service
-          yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+          yield* addPlugin()
 
           yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("cloudflare-ai-gateway", "openai/gpt-5"),
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-ai-gateway"), ModelV2.ID.make("openai/gpt-5")),
+                api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+              }),
               package: "ai-gateway-provider",
               options: {
                 name: "cloudflare-ai-gateway",
@@ -239,12 +287,15 @@ describe("CloudflareAIGatewayPlugin", () => {
       Effect.gen(function* () {
         resetCalls()
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+        yield* addPlugin()
 
         yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-ai-gateway", "openai/gpt-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-ai-gateway"), ModelV2.ID.make("openai/gpt-5")),
+              api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "ai-gateway-provider",
             options: { name: "cloudflare-ai-gateway" },
           },
@@ -261,12 +312,15 @@ describe("CloudflareAIGatewayPlugin", () => {
       Effect.gen(function* () {
         resetCalls()
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+        yield* addPlugin()
 
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-ai-gateway", "openai/gpt-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-ai-gateway"), ModelV2.ID.make("openai/gpt-5")),
+              api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "ai-gateway-provider",
             options: { name: "cloudflare-ai-gateway" },
           },
@@ -284,12 +338,15 @@ describe("CloudflareAIGatewayPlugin", () => {
       Effect.gen(function* () {
         resetCalls()
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+        yield* addPlugin()
 
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-ai-gateway", "openai/gpt-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-ai-gateway"), ModelV2.ID.make("openai/gpt-5")),
+              api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "ai-gateway-provider",
             options: { name: "cloudflare-ai-gateway" },
           },
@@ -313,12 +370,15 @@ describe("CloudflareAIGatewayPlugin", () => {
         Effect.gen(function* () {
           resetCalls()
           const plugin = yield* PluginV2.Service
-          yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+          yield* addPlugin()
 
           const result = yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("cloudflare-ai-gateway", "openai/gpt-5"),
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-ai-gateway"), ModelV2.ID.make("openai/gpt-5")),
+                api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+              }),
               package: "ai-gateway-provider",
               options: { name: "cloudflare-ai-gateway", baseURL: "https://proxy.example/v1" },
             },
@@ -336,12 +396,22 @@ describe("CloudflareAIGatewayPlugin", () => {
       Effect.gen(function* () {
         resetCalls()
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+        yield* addPlugin()
 
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-ai-gateway", "anthropic/claude-sonnet-4-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(
+                ProviderV2.ID.make("cloudflare-ai-gateway"),
+                ModelV2.ID.make("anthropic/claude-sonnet-4-5"),
+              ),
+              api: {
+                id: ModelV2.ID.make("anthropic/claude-sonnet-4-5"),
+                type: "aisdk",
+                package: "test-provider",
+              },
+            }),
             package: "ai-gateway-provider",
             options: { name: "cloudflare-ai-gateway" },
           },
@@ -364,12 +434,15 @@ describe("CloudflareAIGatewayPlugin", () => {
       Effect.gen(function* () {
         resetCalls()
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareAIGatewayPlugin)
+        yield* addPlugin()
 
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-ai-gateway", "openai/gpt-5"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-ai-gateway"), ModelV2.ID.make("openai/gpt-5")),
+              api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/openai-compatible",
             options: { name: "cloudflare-ai-gateway" },
           },

packages/core/test/plugin/provider-cloudflare-workers-ai.test.ts

@@ -3,9 +3,59 @@ import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { CloudflareWorkersAIPlugin } from "@opencode-ai/core/plugin/provider/cloudflare-workers-ai"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, fakeSelectorSdk, it, model, required, withEnv } from "./provider-helper"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: CloudflareWorkersAIPlugin.id, effect: CloudflareWorkersAIPlugin.effect(host) })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, effect: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    effect,
+    (previous) =>
+      Effect.sync(() =>
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        }),
+      ),
+  )
+}
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
 
 function cloudflareLanguage(sdk: unknown, modelID = "@cf/model") {
   return (sdk as { languageModel: (id: string) => { config: CloudflareConfig; provider: string } }).languageModel(
@@ -37,12 +87,15 @@ describe("CloudflareWorkersAIPlugin", () => {
             provider.api = { type: "aisdk", package: "test-provider" }
           }),
         )
-        yield* addPlugin(plugin, CloudflareWorkersAIPlugin)
+        yield* addPlugin()
         const provider = required(yield* catalog.provider.get(ProviderV2.ID.make("cloudflare-workers-ai")))
         const sdk = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-workers-ai", "@cf/model", { api: provider.api }),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-workers-ai"), ModelV2.ID.make("@cf/model")),
+              api: { id: ModelV2.ID.make("@cf/model"), ...provider.api },
+            }),
             package: "@ai-sdk/openai-compatible",
             options: { name: "cloudflare-workers-ai", headers: { custom: "header" } },
           },
@@ -61,14 +114,13 @@ describe("CloudflareWorkersAIPlugin", () => {
   it.effect("preserves a configured endpoint URL instead of deriving one from account ID", () =>
     withEnv({ CLOUDFLARE_ACCOUNT_ID: "acct" }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
         yield* catalog.transform((catalog) =>
           catalog.provider.update(ProviderV2.ID.make("cloudflare-workers-ai"), (provider) => {
             provider.api = { type: "aisdk", package: "test-provider", url: "https://proxy.example/v1" }
           }),
         )
-        yield* addPlugin(plugin, CloudflareWorkersAIPlugin)
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.make("cloudflare-workers-ai"))).api).toEqual({
           type: "aisdk",
           package: "test-provider",
@@ -82,12 +134,18 @@ describe("CloudflareWorkersAIPlugin", () => {
     withEnv({ CLOUDFLARE_ACCOUNT_ID: undefined, CLOUDFLARE_API_KEY: "key" }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareWorkersAIPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-workers-ai", "@cf/model", {
-              api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://proxy.example/v1" },
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-workers-ai"), ModelV2.ID.make("@cf/model")),
+              api: {
+                id: ModelV2.ID.make("@cf/model"),
+                type: "aisdk",
+                package: "@ai-sdk/openai-compatible",
+                url: "https://proxy.example/v1",
+              },
             }),
             package: "@ai-sdk/openai-compatible",
             options: { name: "cloudflare-workers-ai", baseURL: "https://proxy.example/v1" },
@@ -102,7 +160,6 @@ describe("CloudflareWorkersAIPlugin", () => {
   it.effect("uses env account ID over configured account ID", () =>
     withEnv({ CLOUDFLARE_ACCOUNT_ID: "env-acct" }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
         yield* catalog.transform((catalog) =>
           catalog.provider.update(ProviderV2.ID.make("cloudflare-workers-ai"), (provider) => {
@@ -110,7 +167,7 @@ describe("CloudflareWorkersAIPlugin", () => {
             provider.request.body.accountId = "configured-acct"
           }),
         )
-        yield* addPlugin(plugin, CloudflareWorkersAIPlugin)
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.make("cloudflare-workers-ai"))).api).toEqual({
           type: "aisdk",
           package: "test-provider",
@@ -124,12 +181,18 @@ describe("CloudflareWorkersAIPlugin", () => {
     withEnv({ CLOUDFLARE_ACCOUNT_ID: "acct", CLOUDFLARE_API_KEY: "env-key" }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareWorkersAIPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-workers-ai", "@cf/model", {
-              api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://proxy.example/v1" },
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-workers-ai"), ModelV2.ID.make("@cf/model")),
+              api: {
+                id: ModelV2.ID.make("@cf/model"),
+                type: "aisdk",
+                package: "@ai-sdk/openai-compatible",
+                url: "https://proxy.example/v1",
+              },
             }),
             package: "@ai-sdk/openai-compatible",
             options: {
@@ -153,12 +216,14 @@ describe("CloudflareWorkersAIPlugin", () => {
     withEnv({ CLOUDFLARE_ACCOUNT_ID: "acct", CLOUDFLARE_API_KEY: "key" }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareWorkersAIPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-workers-ai", "@cf/model", {
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-workers-ai"), ModelV2.ID.make("@cf/model")),
               api: {
+                id: ModelV2.ID.make("@cf/model"),
                 type: "aisdk",
                 package: "@ai-sdk/openai-compatible",
                 url: "https://api.cloudflare.com/client/v4/accounts/${CLOUDFLARE_ACCOUNT_ID}/ai/v1",
@@ -183,11 +248,14 @@ describe("CloudflareWorkersAIPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, CloudflareWorkersAIPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("cloudflare-workers-ai", "alias", { api: { id: ModelV2.ID.make("@cf/api-model") } }),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-workers-ai"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("@cf/api-model"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: fakeSelectorSdk(calls),
           options: {},
         },
@@ -202,12 +270,18 @@ describe("CloudflareWorkersAIPlugin", () => {
     withEnv({ CLOUDFLARE_ACCOUNT_ID: "acct", CLOUDFLARE_API_KEY: "key" }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, CloudflareWorkersAIPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("cloudflare-workers-ai", "@cf/model", {
-              api: { type: "aisdk", package: "@ai-sdk/anthropic", url: "https://proxy.example/v1" },
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-workers-ai"), ModelV2.ID.make("@cf/model")),
+              api: {
+                id: ModelV2.ID.make("@cf/model"),
+                type: "aisdk",
+                package: "@ai-sdk/anthropic",
+                url: "https://proxy.example/v1",
+              },
             }),
             package: "@ai-sdk/anthropic",
             options: { name: "cloudflare-workers-ai" },

packages/core/test/plugin/provider-cohere.test.ts

@@ -2,10 +2,34 @@ import { describe, expect, mock } from "bun:test"
 import { Effect } from "effect"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { CoherePlugin } from "@opencode-ai/core/plugin/provider/cohere"
-import { addPlugin, fakeSelectorSdk, it, model } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
 
 const cohereOptions: Record<string, any>[] = []
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: CoherePlugin.id, effect: CoherePlugin.effect(host) })
+})
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
 
 void mock.module("@ai-sdk/cohere", () => ({
   createCohere: (options: Record<string, any>) => {
@@ -24,18 +48,32 @@ describe("CoherePlugin", () => {
   it.effect("creates a Cohere SDK only for @ai-sdk/cohere", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, CoherePlugin)
+      yield* addPlugin()
 
       const ignored = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("cohere", "command"), package: "@ai-sdk/openai-compatible", options: { name: "cohere" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("cohere"), ModelV2.ID.make("command")),
+            api: { id: ModelV2.ID.make("command"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/openai-compatible",
+          options: { name: "cohere" },
+        },
         {},
       )
       expect(ignored.sdk).toBeUndefined()
 
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("cohere", "command"), package: "@ai-sdk/cohere", options: { name: "cohere" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("cohere"), ModelV2.ID.make("command")),
+            api: { id: ModelV2.ID.make("command"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/cohere",
+          options: { name: "cohere" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -45,11 +83,14 @@ describe("CoherePlugin", () => {
   it.effect("uses the model provider ID as the bundled SDK name", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, CoherePlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-cohere", "command-r-plus"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-cohere"), ModelV2.ID.make("command-r-plus")),
+            api: { id: ModelV2.ID.make("command-r-plus"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/cohere",
           options: { name: "custom-cohere", apiKey: "test", baseURL: "https://cohere.example" },
         },
@@ -70,10 +111,17 @@ describe("CoherePlugin", () => {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
       const sdk = fakeSelectorSdk(calls)
-      yield* addPlugin(plugin, CoherePlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
-        { model: model("cohere", "alias", { api: { id: ModelV2.ID.make("command-r-plus") } }), sdk, options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("cohere"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("command-r-plus"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk,
+          options: {},
+        },
         {},
       )
 

packages/core/test/plugin/provider-deepinfra.test.ts

@@ -1,20 +1,25 @@
 import { describe, expect, mock } from "bun:test"
-import { Effect, Layer } from "effect"
-import { AISDK } from "@opencode-ai/core/aisdk"
-import { EventV2 } from "@opencode-ai/core/event"
+import { Effect } from "effect"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { DeepInfraPlugin } from "@opencode-ai/core/plugin/provider/deepinfra"
+import { ProviderV2 } from "@opencode-ai/core/provider"
 import { testEffect } from "../lib/effect"
-import { addPlugin, it, model } from "./provider-helper"
+import { PluginTestLayer } from "./fixture"
 
-const itAISDK = testEffect(
-  Layer.provideMerge(AISDK.layer, PluginV2.locationLayer.pipe(Layer.provide(EventV2.defaultLayer))),
-)
-const deepinfraOptions: Record<string, any>[] = []
+const it = testEffect(PluginTestLayer)
+const deepinfraOptions: Record<string, unknown>[] = []
 const deepinfraLanguageModels: string[] = []
 
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: DeepInfraPlugin.id, effect: DeepInfraPlugin.effect(host) })
+})
+
 void mock.module("@ai-sdk/deepinfra", () => ({
-  createDeepInfra: (options: Record<string, any>) => {
+  createDeepInfra: (options: Record<string, unknown>) => {
     const captured = { ...options }
     deepinfraOptions.push(captured)
     return {
@@ -36,10 +41,17 @@ describe("DeepInfraPlugin", () => {
     Effect.gen(function* () {
       resetDeepInfraMock()
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, DeepInfraPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("deepinfra", "model"), package: "@ai-sdk/deepinfra", options: { name: "deepinfra" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("deepinfra"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "@ai-sdk/deepinfra" },
+          }),
+          package: "@ai-sdk/deepinfra",
+          options: { name: "deepinfra" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -50,11 +62,14 @@ describe("DeepInfraPlugin", () => {
     Effect.gen(function* () {
       resetDeepInfraMock()
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, DeepInfraPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-deepinfra", "model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-deepinfra"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "@ai-sdk/deepinfra" },
+          }),
           package: "@ai-sdk/deepinfra",
           options: { name: "custom-deepinfra", apiKey: "test" },
         },
@@ -69,11 +84,14 @@ describe("DeepInfraPlugin", () => {
     Effect.gen(function* () {
       resetDeepInfraMock()
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, DeepInfraPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("deepinfra", "model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("deepinfra"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "@ai-sdk/deepinfra" },
+          }),
           package: "@ai-sdk/deepinfra",
           options: { name: "deepinfra", apiKey: "test" },
         },
@@ -88,7 +106,7 @@ describe("DeepInfraPlugin", () => {
     Effect.gen(function* () {
       resetDeepInfraMock()
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, DeepInfraPlugin)
+      yield* addPlugin()
       const packages = [
         "unmatched-package",
         "@ai-sdk/deepinfra-compatible",
@@ -98,7 +116,14 @@ describe("DeepInfraPlugin", () => {
         Effect.gen(function* () {
           const ignored = yield* plugin.trigger(
             "aisdk.sdk",
-            { model: model("deepinfra", "model"), package: item, options: { name: "deepinfra" } },
+            {
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.make("deepinfra"), ModelV2.ID.make("model")),
+                api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "@ai-sdk/deepinfra" },
+              }),
+              package: item,
+              options: { name: "deepinfra" },
+            },
             {},
           )
           expect(ignored.sdk).toBeUndefined()
@@ -106,7 +131,14 @@ describe("DeepInfraPlugin", () => {
       )
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("deepinfra", "model"), package: "@ai-sdk/deepinfra", options: { name: "deepinfra" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("deepinfra"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "@ai-sdk/deepinfra" },
+          }),
+          package: "@ai-sdk/deepinfra",
+          options: { name: "deepinfra" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -114,17 +146,36 @@ describe("DeepInfraPlugin", () => {
     }),
   )
 
-  itAISDK.effect("uses the default languageModel selection for DeepInfra models", () =>
+  it.effect("uses the default languageModel selection for DeepInfra models", () =>
     Effect.gen(function* () {
       resetDeepInfraMock()
       const plugin = yield* PluginV2.Service
-      const aisdk = yield* AISDK.Service
-      yield* addPlugin(plugin, DeepInfraPlugin)
-      const language = yield* aisdk.language(
-        model("deepinfra", "meta-llama/Llama-3.3-70B-Instruct", {
-          api: { type: "aisdk", package: "@ai-sdk/deepinfra" },
-        }),
+      yield* addPlugin()
+      const sdkEvent = yield* plugin.trigger(
+        "aisdk.sdk",
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(
+              ProviderV2.ID.make("deepinfra"),
+              ModelV2.ID.make("meta-llama/Llama-3.3-70B-Instruct"),
+            ),
+            api: {
+              id: ModelV2.ID.make("meta-llama/Llama-3.3-70B-Instruct"),
+              type: "aisdk",
+              package: "@ai-sdk/deepinfra",
+            },
+          }),
+          package: "@ai-sdk/deepinfra",
+          options: { name: "deepinfra" },
+        },
+        {},
       )
+      const result = yield* plugin.trigger(
+        "aisdk.language",
+        { model: sdkEvent.model, sdk: sdkEvent.sdk, options: sdkEvent.options },
+        {},
+      )
+      const language = result.language ?? result.sdk.languageModel(result.model.api.id)
       expect(language.provider).toBe("deepinfra.chat")
       expect(deepinfraLanguageModels).toEqual(["meta-llama/Llama-3.3-70B-Instruct"])
     }),

packages/core/test/plugin/provider-dynamic.test.ts

@@ -1,43 +1,40 @@
 import { Npm } from "@opencode-ai/core/npm"
 import { describe, expect } from "bun:test"
-import { Cause, Effect, Layer, Option } from "effect"
+import { Cause, Effect, Layer } from "effect"
 import fs from "fs/promises"
 import os from "os"
 import path from "path"
 import { fileURLToPath } from "url"
 import { AISDK } from "@opencode-ai/core/aisdk"
-import { EventV2 } from "@opencode-ai/core/event"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { DynamicProviderPlugin } from "@opencode-ai/core/plugin/provider/dynamic"
+import { ProviderV2 } from "@opencode-ai/core/provider"
 import { testEffect } from "../lib/effect"
-import { host } from "./host"
-import { fixtureProvider, it, model, npmLayer } from "./provider-helper"
+import { PluginTestLayer } from "./fixture"
 
+const fixtureProvider = new URL("./fixtures/provider-factory.ts", import.meta.url).href
 const fixtureProviderPath = fileURLToPath(fixtureProvider)
-const itWithAISDK = testEffect(
-  AISDK.layer.pipe(Layer.provideMerge(PluginV2.locationLayer.pipe(Layer.provide(EventV2.defaultLayer)))),
-)
+const it = testEffect(PluginTestLayer)
+const itWithAISDK = testEffect(AISDK.layer.pipe(Layer.provideMerge(PluginTestLayer)))
 
-function npmEntrypointLayer(entrypoint?: string) {
-  return Layer.succeed(
-    Npm.Service,
-    Npm.Service.of({
-      add: () => Effect.succeed({ directory: "", entrypoint }),
-      install: () => Effect.void,
-      which: () => Effect.succeed(undefined),
-    }),
-  )
+function npmEntrypoint(entrypoint?: string) {
+  return Npm.Service.of({
+    add: () => Effect.succeed({ directory: "", entrypoint }),
+    install: () => Effect.void,
+    which: () => Effect.succeed(undefined),
+  })
 }
 
-function dynamicPlugin(layer = npmLayer) {
-  return {
+const addPlugin = Effect.fn(function* (npm?: Npm.Interface) {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({
     id: DynamicProviderPlugin.id,
-    effect: Effect.gen(function* () {
-      yield* DynamicProviderPlugin.effect(host({ npm: yield* Npm.Service }))
-    }).pipe(Effect.provide(layer)),
-  }
-}
+    effect: DynamicProviderPlugin.effect(npm ? { ...host, npm } : host),
+  })
+})
 
 function tempEntrypoint(source: string) {
   return Effect.acquireRelease(
@@ -55,11 +52,14 @@ describe("DynamicProviderPlugin", () => {
   it.effect("creates an SDK from a provider factory export", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* plugin.add(dynamicPlugin())
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom", "test-model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom"), ModelV2.ID.make("test-model")),
+            api: { id: ModelV2.ID.make("test-model"), type: "aisdk", package: fixtureProvider },
+          }),
           package: fixtureProvider,
           options: { name: "custom", marker: "dynamic" },
         },
@@ -74,11 +74,14 @@ describe("DynamicProviderPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const sdk = { marker: "existing" }
-      yield* plugin.add(dynamicPlugin())
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom", "test-model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom"), ModelV2.ID.make("test-model")),
+            api: { id: ModelV2.ID.make("test-model"), type: "aisdk", package: fixtureProvider },
+          }),
           package: fixtureProvider,
           options: { name: "custom", marker: "dynamic" },
         },
@@ -91,11 +94,14 @@ describe("DynamicProviderPlugin", () => {
   it.effect("injects the provider ID as the SDK factory name", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* plugin.add(dynamicPlugin())
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-provider", "test-model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-provider"), ModelV2.ID.make("test-model")),
+            api: { id: ModelV2.ID.make("test-model"), type: "aisdk", package: fixtureProvider },
+          }),
           package: fixtureProvider,
           options: { name: "custom-provider", marker: "dynamic" },
         },
@@ -108,11 +114,14 @@ describe("DynamicProviderPlugin", () => {
   it.effect("loads npm packages through their resolved import entrypoint", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* plugin.add(dynamicPlugin(npmEntrypointLayer(fixtureProviderPath)))
+      yield* addPlugin(npmEntrypoint(fixtureProviderPath))
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("npm-provider", "test-model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("npm-provider"), ModelV2.ID.make("test-model")),
+            api: { id: ModelV2.ID.make("test-model"), type: "aisdk", package: "fixture-provider" },
+          }),
           package: "fixture-provider",
           options: { name: "npm-provider", marker: "npm" },
         },
@@ -126,9 +135,14 @@ describe("DynamicProviderPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const aisdk = yield* AISDK.Service
-      yield* plugin.add(dynamicPlugin(npmEntrypointLayer()))
+      yield* addPlugin(npmEntrypoint())
       const exit = yield* aisdk
-        .language(model("missing-entrypoint", "alias", { api: { type: "aisdk", package: "fixture-provider" } }))
+        .language(
+          new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("missing-entrypoint"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("alias"), type: "aisdk", package: "fixture-provider" },
+          }),
+        )
         .pipe(Effect.exit)
       expect(exit._tag).toBe("Failure")
       if (exit._tag === "Failure") expect(Cause.prettyErrors(exit.cause).join("\n")).toContain("AISDK.InitError")
@@ -139,10 +153,13 @@ describe("DynamicProviderPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const aisdk = yield* AISDK.Service
-      yield* plugin.add(dynamicPlugin())
+      yield* addPlugin()
       const exit = yield* aisdk
         .language(
-          model("bad-import", "alias", { api: { type: "aisdk", package: "file:///missing/provider-factory.js" } }),
+          new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("bad-import"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("alias"), type: "aisdk", package: "file:///missing/provider-factory.js" },
+          }),
         )
         .pipe(Effect.exit)
       expect(exit._tag).toBe("Failure")
@@ -155,9 +172,14 @@ describe("DynamicProviderPlugin", () => {
       const plugin = yield* PluginV2.Service
       const aisdk = yield* AISDK.Service
       const tmp = yield* tempEntrypoint("export const notAProviderFactory = true\n")
-      yield* plugin.add(dynamicPlugin(npmEntrypointLayer(tmp.entrypoint)))
+      yield* addPlugin(npmEntrypoint(tmp.entrypoint))
       const exit = yield* aisdk
-        .language(model("missing-factory", "alias", { api: { type: "aisdk", package: "fixture-provider" } }))
+        .language(
+          new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("missing-factory"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("alias"), type: "aisdk", package: "fixture-provider" },
+          }),
+        )
         .pipe(Effect.exit)
       expect(exit._tag).toBe("Failure")
       if (exit._tag === "Failure") expect(Cause.prettyErrors(exit.cause).join("\n")).toContain("AISDK.InitError")
@@ -168,9 +190,10 @@ describe("DynamicProviderPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const aisdk = yield* AISDK.Service
-      yield* plugin.add(dynamicPlugin())
+      yield* addPlugin()
       const language = yield* aisdk.language(
-        model("custom", "alias", {
+        new ModelV2.Info({
+          ...ModelV2.Info.empty(ProviderV2.ID.make("custom"), ModelV2.ID.make("alias")),
           api: { id: ModelV2.ID.make("test-model-api"), type: "aisdk", package: fixtureProvider },
         }),
       )

packages/core/test/plugin/provider-gateway.test.ts

@@ -1,11 +1,22 @@
 import { describe, expect, mock } from "bun:test"
 import { Effect } from "effect"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { GatewayPlugin } from "@opencode-ai/core/plugin/provider/gateway"
-import { addPlugin, it, model } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
 
 const gatewayCalls: Record<string, unknown>[] = []
 const vercelGatewayModels = ["anthropic/claude-sonnet-4", "openai/gpt-5", "google/gemini-2.5-pro"]
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: GatewayPlugin.id, effect: GatewayPlugin.effect(host) })
+})
 
 mock.module("@ai-sdk/gateway", () => ({
   createGateway(options: Record<string, unknown>) {
@@ -27,10 +38,17 @@ describe("GatewayPlugin", () => {
     Effect.gen(function* () {
       gatewayCalls.length = 0
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GatewayPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("gateway", "model"), package: "@ai-sdk/gateway", options: { name: "gateway" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("gateway"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/gateway",
+          options: { name: "gateway" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -42,12 +60,19 @@ describe("GatewayPlugin", () => {
     Effect.gen(function* () {
       gatewayCalls.length = 0
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GatewayPlugin)
+      yield* addPlugin()
 
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("vercel", "anthropic/claude-sonnet-4"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("vercel"), ModelV2.ID.make("anthropic/claude-sonnet-4")),
+            api: {
+              id: ModelV2.ID.make("anthropic/claude-sonnet-4"),
+              type: "aisdk",
+              package: "test-provider",
+            },
+          }),
           package: "@ai-sdk/gateway",
           options: { name: "vercel", apiKey: "test-key" },
         },
@@ -63,19 +88,33 @@ describe("GatewayPlugin", () => {
     Effect.gen(function* () {
       gatewayCalls.length = 0
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GatewayPlugin)
+      yield* addPlugin()
 
       for (const modelID of vercelGatewayModels) {
         const ignored = yield* plugin.trigger(
           "aisdk.sdk",
-          { model: model("vercel", modelID), package: "@ai-sdk/vercel", options: { name: "vercel" } },
+          {
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("vercel"), ModelV2.ID.make(modelID)),
+              api: { id: ModelV2.ID.make(modelID), type: "aisdk", package: "test-provider" },
+            }),
+            package: "@ai-sdk/vercel",
+            options: { name: "vercel" },
+          },
           {},
         )
         expect(ignored.sdk).toBeUndefined()
 
         const result = yield* plugin.trigger(
           "aisdk.sdk",
-          { model: model("vercel", modelID), package: "@ai-sdk/gateway", options: { name: "vercel" } },
+          {
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("vercel"), ModelV2.ID.make(modelID)),
+              api: { id: ModelV2.ID.make(modelID), type: "aisdk", package: "test-provider" },
+            }),
+            package: "@ai-sdk/gateway",
+            options: { name: "vercel" },
+          },
           {},
         )
         expect(result.sdk).toBeDefined()

packages/core/test/plugin/provider-github-copilot.test.ts

@@ -3,19 +3,51 @@ import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { GithubCopilotPlugin } from "@opencode-ai/core/plugin/provider/github-copilot"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, fakeSelectorSdk, it, model, required } from "./provider-helper"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: GithubCopilotPlugin.id, effect: GithubCopilotPlugin.effect(host) })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
 
 describe("GithubCopilotPlugin", () => {
   it.effect("creates the bundled Copilot SDK for the GitHub Copilot package", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GithubCopilotPlugin)
+      yield* addPlugin()
       const ignored = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("github-copilot", "gpt-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("gpt-5")),
+            api: { id: ModelV2.ID.make("gpt-5"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/openai-compatible",
           options: { name: "github-copilot" },
         },
@@ -24,7 +56,10 @@ describe("GithubCopilotPlugin", () => {
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("github-copilot", "gpt-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("gpt-5")),
+            api: { id: ModelV2.ID.make("gpt-5"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/github-copilot",
           options: { name: "github-copilot" },
         },
@@ -39,11 +74,14 @@ describe("GithubCopilotPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, GithubCopilotPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("github-copilot", "claude-sonnet-4"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("claude-sonnet-4")),
+            api: { id: ModelV2.ID.make("claude-sonnet-4"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
           options: {},
         },
@@ -57,11 +95,14 @@ describe("GithubCopilotPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, GithubCopilotPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("github-copilot", "alias", { api: { id: ModelV2.ID.make("claude-sonnet-4") } }),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("claude-sonnet-4"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
           options: {},
         },
@@ -75,30 +116,65 @@ describe("GithubCopilotPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, GithubCopilotPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
-        { model: model("github-copilot", "gpt-5"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("gpt-5")),
+            api: { id: ModelV2.ID.make("gpt-5"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       yield* plugin.trigger(
         "aisdk.language",
-        { model: model("github-copilot", "gpt-5.1-codex"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("gpt-5.1-codex")),
+            api: { id: ModelV2.ID.make("gpt-5.1-codex"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       yield* plugin.trigger(
         "aisdk.language",
-        { model: model("github-copilot", "gpt-4o"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("gpt-4o")),
+            api: { id: ModelV2.ID.make("gpt-4o"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       yield* plugin.trigger(
         "aisdk.language",
-        { model: model("github-copilot", "gpt-5-mini"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("gpt-5-mini")),
+            api: { id: ModelV2.ID.make("gpt-5-mini"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       yield* plugin.trigger(
         "aisdk.language",
-        { model: model("github-copilot", "gpt-5-mini-2025-08-07"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("gpt-5-mini-2025-08-07")),
+            api: { id: ModelV2.ID.make("gpt-5-mini-2025-08-07"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       expect(calls).toEqual([
@@ -115,11 +191,14 @@ describe("GithubCopilotPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, GithubCopilotPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("github-copilot", "default", { api: { id: ModelV2.ID.make("gpt-5") } }),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("default")),
+            api: { id: ModelV2.ID.make("gpt-5"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: fakeSelectorSdk(calls),
           options: {},
         },
@@ -128,7 +207,10 @@ describe("GithubCopilotPlugin", () => {
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("github-copilot", "small", { api: { id: ModelV2.ID.make("gpt-5-mini") } }),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("small")),
+            api: { id: ModelV2.ID.make("gpt-5-mini"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: fakeSelectorSdk(calls),
           options: {},
         },
@@ -137,7 +219,10 @@ describe("GithubCopilotPlugin", () => {
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("github-copilot", "sonnet", { api: { id: ModelV2.ID.make("claude-sonnet-4") } }),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("sonnet")),
+            api: { id: ModelV2.ID.make("claude-sonnet-4"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: fakeSelectorSdk(calls),
           options: {},
         },
@@ -149,13 +234,12 @@ describe("GithubCopilotPlugin", () => {
 
   it.effect("disables gpt-5-chat-latest before Copilot language selection", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, GithubCopilotPlugin)
       yield* catalog.transform((catalog) => {
         catalog.provider.update(ProviderV2.ID.make("github-copilot"), () => {})
         catalog.model.update(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("gpt-5-chat-latest"), () => {})
       })
+      yield* addPlugin()
       expect(
         required(yield* catalog.model.get(ProviderV2.ID.make("github-copilot"), ModelV2.ID.make("gpt-5-chat-latest")))
           .enabled,
@@ -165,13 +249,12 @@ describe("GithubCopilotPlugin", () => {
 
   it.effect("does not disable gpt-5-chat-latest for non-Copilot providers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, GithubCopilotPlugin)
       yield* catalog.transform((catalog) => {
         catalog.provider.update(ProviderV2.ID.make("custom-copilot"), () => {})
         catalog.model.update(ProviderV2.ID.make("custom-copilot"), ModelV2.ID.make("gpt-5-chat-latest"), () => {})
       })
+      yield* addPlugin()
       expect(
         required(yield* catalog.model.get(ProviderV2.ID.make("custom-copilot"), ModelV2.ID.make("gpt-5-chat-latest")))
           .enabled,
@@ -183,10 +266,17 @@ describe("GithubCopilotPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, GithubCopilotPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
-        { model: model("openai", "gpt-5"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("openai"), ModelV2.ID.make("gpt-5")),
+            api: { id: ModelV2.ID.make("gpt-5"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       expect(calls).toEqual([])

packages/core/test/plugin/provider-gitlab.test.ts

@@ -1,12 +1,43 @@
 import { describe, expect, mock } from "bun:test"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { GitLabPlugin } from "@opencode-ai/core/plugin/provider/gitlab"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, it, model, required, withEnv } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
 
 const gitlabSDKOptions: Record<string, unknown>[] = []
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: GitLabPlugin.id, effect: GitLabPlugin.effect(host) })
+})
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, effect: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    effect,
+    (previous) =>
+      Effect.sync(() =>
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        }),
+      ),
+  )
+}
 
 void mock.module("gitlab-ai-provider", () => ({
   VERSION: "test-version",
@@ -32,10 +63,17 @@ describe("GitLabPlugin", () => {
         Effect.gen(function* () {
           gitlabSDKOptions.length = 0
           const plugin = yield* PluginV2.Service
-          yield* addPlugin(plugin, GitLabPlugin)
+          yield* addPlugin()
           yield* plugin.trigger(
             "aisdk.sdk",
-            { model: model("gitlab", "claude"), package: "gitlab-ai-provider", options: { name: "gitlab" } },
+            {
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.make("gitlab"), ModelV2.ID.make("claude")),
+                api: { id: ModelV2.ID.make("claude"), type: "aisdk", package: "test-provider" },
+              }),
+              package: "gitlab-ai-provider",
+              options: { name: "gitlab" },
+            },
             {},
           )
           expect(gitlabSDKOptions).toHaveLength(1)
@@ -65,10 +103,17 @@ describe("GitLabPlugin", () => {
         Effect.gen(function* () {
           gitlabSDKOptions.length = 0
           const plugin = yield* PluginV2.Service
-          yield* addPlugin(plugin, GitLabPlugin)
+          yield* addPlugin()
           yield* plugin.trigger(
             "aisdk.sdk",
-            { model: model("gitlab", "claude"), package: "gitlab-ai-provider", options: { name: "gitlab" } },
+            {
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.make("gitlab"), ModelV2.ID.make("claude")),
+                api: { id: ModelV2.ID.make("claude"), type: "aisdk", package: "test-provider" },
+              }),
+              package: "gitlab-ai-provider",
+              options: { name: "gitlab" },
+            },
             {},
           )
           expect(gitlabSDKOptions[0].instanceUrl).toBe("https://env.gitlab.example")
@@ -86,11 +131,14 @@ describe("GitLabPlugin", () => {
         Effect.gen(function* () {
           gitlabSDKOptions.length = 0
           const plugin = yield* PluginV2.Service
-          yield* addPlugin(plugin, GitLabPlugin)
+          yield* addPlugin()
           yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("gitlab", "claude"),
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.make("gitlab"), ModelV2.ID.make("claude")),
+                api: { id: ModelV2.ID.make("claude"), type: "aisdk", package: "test-provider" },
+              }),
               package: "gitlab-ai-provider",
               options: {
                 name: "gitlab",
@@ -127,10 +175,17 @@ describe("GitLabPlugin", () => {
     Effect.gen(function* () {
       gitlabSDKOptions.length = 0
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GitLabPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("gitlab", "claude"), package: "@ai-sdk/openai", options: { name: "gitlab" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("gitlab"), ModelV2.ID.make("claude")),
+            api: { id: ModelV2.ID.make("claude"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/openai",
+          options: { name: "gitlab" },
+        },
         {},
       )
       expect(result.sdk).toBeUndefined()
@@ -142,11 +197,13 @@ describe("GitLabPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: [string, unknown][] = []
-      yield* addPlugin(plugin, GitLabPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("gitlab", "duo-workflow-custom", {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("gitlab"), ModelV2.ID.make("duo-workflow-custom")),
+            api: { id: ModelV2.ID.make("duo-workflow-custom"), type: "aisdk", package: "test-provider" },
             request: {
               headers: {},
               body: { workflowRef: "ref", workflowDefinition: "definition" },
@@ -178,11 +235,14 @@ describe("GitLabPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: [string, unknown][] = []
-      yield* addPlugin(plugin, GitLabPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("gitlab", "duo-workflow-exact"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("gitlab"), ModelV2.ID.make("duo-workflow-exact")),
+            api: { id: ModelV2.ID.make("duo-workflow-exact"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: {
             workflowChat: (id: string, options: unknown) => {
               calls.push([id, options])
@@ -205,11 +265,13 @@ describe("GitLabPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: [string, unknown][] = []
-      yield* addPlugin(plugin, GitLabPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("gitlab", "duo-workflow-custom", {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("gitlab"), ModelV2.ID.make("duo-workflow-custom")),
+            api: { id: ModelV2.ID.make("duo-workflow-custom"), type: "aisdk", package: "test-provider" },
             request: {
               headers: {},
               body: { featureFlags: { request_flag: true } },
@@ -234,11 +296,13 @@ describe("GitLabPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: [string, unknown][] = []
-      yield* addPlugin(plugin, GitLabPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("gitlab", "claude", {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("gitlab"), ModelV2.ID.make("claude")),
+            api: { id: ModelV2.ID.make("claude"), type: "aisdk", package: "test-provider" },
             request: { headers: { h: "v" }, body: {} },
           }),
           sdk: {

packages/core/test/plugin/provider-google-vertex-anthropic.test.ts

@@ -1,10 +1,50 @@
+import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { describe, expect } from "bun:test"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { GoogleVertexAnthropicPlugin, GoogleVertexPlugin } from "@opencode-ai/core/plugin/provider/google-vertex"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, fakeSelectorSdk, it, model, required, withEnv } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* (definition: typeof GoogleVertexAnthropicPlugin | typeof GoogleVertexPlugin) {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: definition.id, effect: definition.effect(host) })
+})
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, effect: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    effect,
+    (previous) =>
+      Effect.sync(() => {
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        })
+      }),
+  )
+}
+
+function selector(calls: string[]) {
+  return (id: string) => {
+    calls.push(`languageModel:${id}`)
+    return { modelId: id, provider: "languageModel", specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+}
 
 describe("GoogleVertexAnthropicPlugin", () => {
   it.effect("resolves legacy project and location env on provider update", () =>
@@ -19,17 +59,19 @@ describe("GoogleVertexAnthropicPlugin", () => {
       },
       () =>
         Effect.gen(function* () {
-          const plugin = yield* PluginV2.Service
           const catalog = yield* Catalog.Service
-          yield* addPlugin(plugin, GoogleVertexAnthropicPlugin)
           yield* catalog.transform((catalog) =>
             catalog.provider.update(ProviderV2.ID.make("google-vertex-anthropic"), (provider) => {
               provider.api = { type: "aisdk", package: "@ai-sdk/google-vertex/anthropic" }
             }),
           )
-          const provider = required(yield* catalog.provider.get(ProviderV2.ID.make("google-vertex-anthropic")))
-          expect(provider.request.body.project).toBe("cloud-project")
-          expect(provider.request.body.location).toBe("cloud-location")
+          yield* addPlugin(GoogleVertexAnthropicPlugin)
+          expect(
+            (yield* catalog.provider.get(ProviderV2.ID.make("google-vertex-anthropic")))?.request.body.project,
+          ).toBe("cloud-project")
+          expect(
+            (yield* catalog.provider.get(ProviderV2.ID.make("google-vertex-anthropic")))?.request.body.location,
+          ).toBe("cloud-location")
         }),
     ),
   )
@@ -37,9 +79,7 @@ describe("GoogleVertexAnthropicPlugin", () => {
   it.effect("keeps configured project and location over env fallback", () =>
     withEnv({ GOOGLE_CLOUD_PROJECT: "env-project", GOOGLE_CLOUD_LOCATION: "env-location" }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
-        yield* addPlugin(plugin, GoogleVertexAnthropicPlugin)
         yield* catalog.transform((catalog) =>
           catalog.provider.update(ProviderV2.ID.make("google-vertex-anthropic"), (provider) => {
             provider.api = { type: "aisdk", package: "@ai-sdk/google-vertex/anthropic" }
@@ -47,9 +87,13 @@ describe("GoogleVertexAnthropicPlugin", () => {
             provider.request.body.location = "configured-location"
           }),
         )
-        const provider = required(yield* catalog.provider.get(ProviderV2.ID.make("google-vertex-anthropic")))
-        expect(provider.request.body.project).toBe("configured-project")
-        expect(provider.request.body.location).toBe("configured-location")
+        yield* addPlugin(GoogleVertexAnthropicPlugin)
+        expect((yield* catalog.provider.get(ProviderV2.ID.make("google-vertex-anthropic")))?.request.body.project).toBe(
+          "configured-project",
+        )
+        expect(
+          (yield* catalog.provider.get(ProviderV2.ID.make("google-vertex-anthropic")))?.request.body.location,
+        ).toBe("configured-location")
       }),
     ),
   )
@@ -67,11 +111,17 @@ describe("GoogleVertexAnthropicPlugin", () => {
       () =>
         Effect.gen(function* () {
           const plugin = yield* PluginV2.Service
-          yield* addPlugin(plugin, GoogleVertexAnthropicPlugin)
+          yield* addPlugin(GoogleVertexAnthropicPlugin)
           const result = yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("google-vertex-anthropic", "claude-sonnet-4-5"),
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(
+                  ProviderV2.ID.make("google-vertex-anthropic"),
+                  ModelV2.ID.make("claude-sonnet-4-5"),
+                ),
+                api: { id: ModelV2.ID.make("claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+              }),
               package: "@ai-sdk/google-vertex/anthropic",
               options: { name: "google-vertex-anthropic" },
             },
@@ -90,11 +140,17 @@ describe("GoogleVertexAnthropicPlugin", () => {
       () =>
         Effect.gen(function* () {
           const plugin = yield* PluginV2.Service
-          yield* addPlugin(plugin, GoogleVertexAnthropicPlugin)
+          yield* addPlugin(GoogleVertexAnthropicPlugin)
           const result = yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("google-vertex-anthropic", "claude-sonnet-4-5"),
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(
+                  ProviderV2.ID.make("google-vertex-anthropic"),
+                  ModelV2.ID.make("claude-sonnet-4-5"),
+                ),
+                api: { id: ModelV2.ID.make("claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+              }),
               package: "@ai-sdk/google-vertex/anthropic",
               options: { name: "google-vertex-anthropic" },
             },
@@ -110,11 +166,14 @@ describe("GoogleVertexAnthropicPlugin", () => {
   it.effect("creates SDKs for google-vertex Anthropic models with multi-region endpoints", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GoogleVertexAnthropicPlugin)
+      yield* addPlugin(GoogleVertexAnthropicPlugin)
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("google-vertex", "claude-sonnet-4-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("google-vertex"), ModelV2.ID.make("claude-sonnet-4-5")),
+            api: { id: ModelV2.ID.make("claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/google-vertex/anthropic",
           options: { name: "google-vertex", project: "project", location: "eu" },
         },
@@ -129,11 +188,14 @@ describe("GoogleVertexAnthropicPlugin", () => {
   it.effect("keeps configured baseURL for google-vertex Anthropic models", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GoogleVertexAnthropicPlugin)
+      yield* addPlugin(GoogleVertexAnthropicPlugin)
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("google-vertex", "claude-sonnet-4-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("google-vertex"), ModelV2.ID.make("claude-sonnet-4-5")),
+            api: { id: ModelV2.ID.make("claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/google-vertex/anthropic",
           options: { name: "google-vertex", project: "project", location: "eu", baseURL: "https://proxy.example/v1" },
         },
@@ -146,12 +208,15 @@ describe("GoogleVertexAnthropicPlugin", () => {
   it.effect("selects google-vertex Anthropic language models through V2 plugins", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GoogleVertexPlugin)
-      yield* addPlugin(plugin, GoogleVertexAnthropicPlugin)
+      yield* addPlugin(GoogleVertexPlugin)
+      yield* addPlugin(GoogleVertexAnthropicPlugin)
       const sdkResult = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("google-vertex", " claude-sonnet-4-5 "),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("google-vertex"), ModelV2.ID.make(" claude-sonnet-4-5 ")),
+            api: { id: ModelV2.ID.make(" claude-sonnet-4-5 "), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/google-vertex/anthropic",
           options: { name: "google-vertex", project: "project", location: "us" },
         },
@@ -160,7 +225,10 @@ describe("GoogleVertexAnthropicPlugin", () => {
       const languageResult = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("google-vertex", " claude-sonnet-4-5 "),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("google-vertex"), ModelV2.ID.make(" claude-sonnet-4-5 ")),
+            api: { id: ModelV2.ID.make(" claude-sonnet-4-5 "), type: "aisdk", package: "test-provider" },
+          }),
           sdk: sdkResult.sdk,
           options: {},
         },
@@ -178,12 +246,18 @@ describe("GoogleVertexAnthropicPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, GoogleVertexAnthropicPlugin)
+      yield* addPlugin(GoogleVertexAnthropicPlugin)
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("google-vertex-anthropic", " claude-sonnet-4-5 "),
-          sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(
+              ProviderV2.ID.make("google-vertex-anthropic"),
+              ModelV2.ID.make(" claude-sonnet-4-5 "),
+            ),
+            api: { id: ModelV2.ID.make(" claude-sonnet-4-5 "), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: { languageModel: selector(calls) },
           options: {},
         },
         {},
@@ -196,12 +270,15 @@ describe("GoogleVertexAnthropicPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, GoogleVertexAnthropicPlugin)
+      yield* addPlugin(GoogleVertexAnthropicPlugin)
       const result = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("google-vertex", "claude-sonnet-4-5"),
-          sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("google-vertex"), ModelV2.ID.make("claude-sonnet-4-5")),
+            api: { id: ModelV2.ID.make("claude-sonnet-4-5"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: { languageModel: selector(calls) },
           options: {},
         },
         {},

packages/core/test/plugin/provider-google-vertex.test.ts

@@ -1,13 +1,63 @@
 import { describe, expect, mock } from "bun:test"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { GoogleVertexPlugin } from "@opencode-ai/core/plugin/provider/google-vertex"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, fakeSelectorSdk, it, model, required, withEnv } from "./provider-helper"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
 
 const vertexOptions: Record<string, any>[] = []
 const googleAuthOptions: Record<string, any>[] = []
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: GoogleVertexPlugin.id, effect: GoogleVertexPlugin.effect(host) })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, effect: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    effect,
+    (previous) =>
+      Effect.sync(() =>
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        }),
+      ),
+  )
+}
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
 
 void mock.module("@ai-sdk/google-vertex", () => ({
   createVertex: (options: Record<string, any>) => {
@@ -37,9 +87,7 @@ void mock.module("google-auth-library", () => ({
 describe("GoogleVertexPlugin", () => {
   it.effect("ignores OpenAI-compatible providers that are not Google Vertex", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, GoogleVertexPlugin)
       yield* catalog.transform((catalog) =>
         catalog.provider.update(ProviderV2.ID.opencode, (provider) => {
           provider.api = {
@@ -49,6 +97,7 @@ describe("GoogleVertexPlugin", () => {
           }
         }),
       )
+      yield* addPlugin()
 
       const provider = required(yield* catalog.provider.get(ProviderV2.ID.opencode))
       expect(provider.request.body).toEqual({})
@@ -67,9 +116,7 @@ describe("GoogleVertexPlugin", () => {
       },
       () =>
         Effect.gen(function* () {
-          const plugin = yield* PluginV2.Service
           const catalog = yield* Catalog.Service
-          yield* addPlugin(plugin, GoogleVertexPlugin)
           yield* catalog.transform((catalog) =>
             catalog.provider.update(ProviderV2.ID.make("google-vertex"), (provider) => {
               provider.api = {
@@ -79,6 +126,7 @@ describe("GoogleVertexPlugin", () => {
               }
             }),
           )
+          yield* addPlugin()
           const provider = required(yield* catalog.provider.get(ProviderV2.ID.make("google-vertex")))
           expect(provider.request.body.project).toBe("google-cloud-project")
           expect(provider.request.body.location).toBe("google-vertex-location")
@@ -107,7 +155,6 @@ describe("GoogleVertexPlugin", () => {
           vertexOptions.length = 0
           const plugin = yield* PluginV2.Service
           const catalog = yield* Catalog.Service
-          yield* addPlugin(plugin, GoogleVertexPlugin)
           yield* catalog.transform((catalog) =>
             catalog.provider.update(ProviderV2.ID.make("google-vertex"), (provider) => {
               provider.api = {
@@ -117,12 +164,18 @@ describe("GoogleVertexPlugin", () => {
               }
             }),
           )
+          yield* addPlugin()
           const provider = required(yield* catalog.provider.get(ProviderV2.ID.make("google-vertex")))
           yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("google-vertex", "gemini", {
-                api: { type: "aisdk", package: "@ai-sdk/google-vertex" },
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.make("google-vertex"), ModelV2.ID.make("gemini")),
+                api: {
+                  id: ModelV2.ID.make("gemini"),
+                  type: "aisdk",
+                  package: "@ai-sdk/google-vertex",
+                },
               }),
               package: "@ai-sdk/google-vertex",
               options: { name: "google-vertex" },
@@ -154,9 +207,7 @@ describe("GoogleVertexPlugin", () => {
       },
       () =>
         Effect.gen(function* () {
-          const plugin = yield* PluginV2.Service
           const catalog = yield* Catalog.Service
-          yield* addPlugin(plugin, GoogleVertexPlugin)
           yield* catalog.transform((catalog) =>
             catalog.provider.update(ProviderV2.ID.make("google-vertex"), (provider) => {
               provider.api = {
@@ -168,6 +219,7 @@ describe("GoogleVertexPlugin", () => {
               provider.request.body.location = "global"
             }),
           )
+          yield* addPlugin()
           const provider = required(yield* catalog.provider.get(ProviderV2.ID.make("google-vertex")))
           expect(provider.request.body.project).toBe("config-project")
           expect(provider.request.body.location).toBe("global")
@@ -182,9 +234,7 @@ describe("GoogleVertexPlugin", () => {
 
   it.effect("keeps OpenAI-compatible Vertex endpoint templates regional for eu", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, GoogleVertexPlugin)
       yield* catalog.transform((catalog) =>
         catalog.provider.update(ProviderV2.ID.make("google-vertex"), (provider) => {
           provider.api = {
@@ -196,6 +246,7 @@ describe("GoogleVertexPlugin", () => {
           provider.request.body.location = "eu"
         }),
       )
+      yield* addPlugin()
       const provider = required(yield* catalog.provider.get(ProviderV2.ID.make("google-vertex")))
       expect(provider.api).toEqual({
         type: "aisdk",
@@ -217,15 +268,14 @@ describe("GoogleVertexPlugin", () => {
       },
       () =>
         Effect.gen(function* () {
-          const plugin = yield* PluginV2.Service
           const catalog = yield* Catalog.Service
-          yield* addPlugin(plugin, GoogleVertexPlugin)
           yield* catalog.transform((catalog) =>
             catalog.provider.update(ProviderV2.ID.make("google-vertex"), (provider) => {
               provider.api = { type: "aisdk", package: "@ai-sdk/google-vertex" }
               provider.request.body.project = "config-project"
             }),
           )
+          yield* addPlugin()
           const provider = required(yield* catalog.provider.get(ProviderV2.ID.make("google-vertex")))
           expect(provider.request.body.project).toBe("config-project")
           expect(provider.request.body.location).toBe("us-central1")
@@ -243,12 +293,17 @@ describe("GoogleVertexPlugin", () => {
         Effect.gen(function* () {
           vertexOptions.length = 0
           const plugin = yield* PluginV2.Service
-          yield* addPlugin(plugin, GoogleVertexPlugin)
+          yield* addPlugin()
           yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("google-vertex", "gemini", {
-                api: { type: "aisdk", package: "@ai-sdk/google-vertex" },
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.make("google-vertex"), ModelV2.ID.make("gemini")),
+                api: {
+                  id: ModelV2.ID.make("gemini"),
+                  type: "aisdk",
+                  package: "@ai-sdk/google-vertex",
+                },
               }),
               package: "@ai-sdk/google-vertex",
               options: { name: "google-vertex" },
@@ -268,21 +323,17 @@ describe("GoogleVertexPlugin", () => {
       googleAuthOptions.length = 0
       const fetchCalls: { input: Parameters<typeof fetch>[0]; init?: RequestInit }[] = []
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GoogleVertexPlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("capture-openai-compatible"),
-        effect: Effect.succeed({
-          "aisdk.sdk": (evt) =>
-            Effect.promise(async () => {
-              if (evt.model.providerID !== "google-vertex") return
-              if (evt.package !== "@ai-sdk/openai-compatible") return
-              expect(typeof evt.options.fetch).toBe("function")
-              await evt.options.fetch("https://vertex.example", {
-                headers: { "x-test": "1" },
-              })
-            }),
+      yield* addPlugin()
+      yield* plugin.hook("aisdk.sdk", (evt) =>
+        Effect.promise(async () => {
+          if (evt.model.providerID !== "google-vertex") return
+          if (evt.package !== "@ai-sdk/openai-compatible") return
+          expect(typeof evt.options.fetch).toBe("function")
+          await evt.options.fetch("https://vertex.example", {
+            headers: { "x-test": "1" },
+          })
         }),
-      })
+      )
       const originalFetch = fetch
       ;(globalThis as typeof globalThis & { fetch: typeof fetch }).fetch = (async (
         input: Parameters<typeof fetch>[0],
@@ -297,8 +348,13 @@ describe("GoogleVertexPlugin", () => {
           plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("google-vertex", "gemini", {
-                api: { type: "aisdk", package: "@ai-sdk/openai-compatible" },
+              model: new ModelV2.Info({
+                ...ModelV2.Info.empty(ProviderV2.ID.make("google-vertex"), ModelV2.ID.make("gemini")),
+                api: {
+                  id: ModelV2.ID.make("gemini"),
+                  type: "aisdk",
+                  package: "@ai-sdk/openai-compatible",
+                },
               }),
               package: "@ai-sdk/openai-compatible",
               options: { name: "google-vertex" },
@@ -322,11 +378,14 @@ describe("GoogleVertexPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, GoogleVertexPlugin)
+      yield* addPlugin()
       yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("google-vertex", " gemini-2.5-pro "),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("google-vertex"), ModelV2.ID.make(" gemini-2.5-pro ")),
+            api: { id: ModelV2.ID.make(" gemini-2.5-pro "), type: "aisdk", package: "test-provider" },
+          }),
           sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
           options: {},
         },

packages/core/test/plugin/provider-google.test.ts

@@ -1,26 +1,33 @@
 import { describe, expect } from "bun:test"
-import { Effect, Layer } from "effect"
-import { AISDK } from "@opencode-ai/core/aisdk"
-import { EventV2 } from "@opencode-ai/core/event"
+import { Effect } from "effect"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { GooglePlugin } from "@opencode-ai/core/plugin/provider/google"
+import { ProviderV2 } from "@opencode-ai/core/provider"
 import { testEffect } from "../lib/effect"
-import { addPlugin, it, model } from "./provider-helper"
+import { PluginTestLayer } from "./fixture"
 
-const itWithAISDK = testEffect(
-  AISDK.layer.pipe(Layer.provideMerge(PluginV2.locationLayer.pipe(Layer.provide(EventV2.defaultLayer)))),
-)
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: GooglePlugin.id, effect: GooglePlugin.effect(host) })
+})
 
 describe("GooglePlugin", () => {
   it.effect("creates a Google Generative AI SDK for @ai-sdk/google using the provider ID as SDK name", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GooglePlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-google", "gemini"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-google"), ModelV2.ID.make("gemini")),
+            api: { id: ModelV2.ID.make("gemini"), type: "aisdk", package: "@ai-sdk/google" },
+          }),
           package: "@ai-sdk/google",
           options: { name: "custom-google", apiKey: "test" },
         },
@@ -34,34 +41,49 @@ describe("GooglePlugin", () => {
   it.effect("ignores non-Google SDK packages", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GooglePlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("google", "gemini"), package: "@ai-sdk/google-vertex", options: { name: "google" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("google"), ModelV2.ID.make("gemini")),
+            api: { id: ModelV2.ID.make("gemini"), type: "aisdk", package: "@ai-sdk/google" },
+          }),
+          package: "@ai-sdk/google-vertex",
+          options: { name: "google" },
+        },
         {},
       )
       expect(result.sdk).toBeUndefined()
     }),
   )
 
-  itWithAISDK.effect("uses default languageModel loading with provider ID parity", () =>
+  it.effect("uses default languageModel loading with provider ID parity", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      const aisdk = yield* AISDK.Service
-      yield* addPlugin(plugin, GooglePlugin)
-      const language = yield* aisdk.language(
-        model("custom-google", "alias", {
-          api: {
-            id: ModelV2.ID.make("gemini-api"),
-            type: "aisdk",
-            package: "@ai-sdk/google",
-          },
-          request: {
-            headers: {},
-            body: { apiKey: "test" },
-          },
-        }),
+      yield* addPlugin()
+      const sdkEvent = yield* plugin.trigger(
+        "aisdk.sdk",
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-google"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("gemini-api"), type: "aisdk", package: "@ai-sdk/google" },
+          }),
+          package: "@ai-sdk/google",
+          options: { name: "custom-google", apiKey: "test" },
+        },
+        {},
       )
+      const result = yield* plugin.trigger(
+        "aisdk.language",
+        {
+          model: sdkEvent.model,
+          sdk: sdkEvent.sdk,
+          options: sdkEvent.options,
+        },
+        {},
+      )
+      const language = result.language ?? result.sdk.languageModel(result.model.api.id)
       expect(language.modelId).toBe("gemini-api")
       expect(language.provider).toBe("custom-google")
     }),

packages/core/test/plugin/provider-groq.test.ts

@@ -1,26 +1,37 @@
 import { describe, expect } from "bun:test"
 import { createGroq } from "@ai-sdk/groq"
-import { Effect, Layer } from "effect"
-import { AISDK } from "@opencode-ai/core/aisdk"
-import { EventV2 } from "@opencode-ai/core/event"
+import { Effect } from "effect"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { GroqPlugin } from "@opencode-ai/core/plugin/provider/groq"
-import { addPlugin, it, model } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
 import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
 
-const aisdkIt = testEffect(
-  AISDK.layer.pipe(Layer.provideMerge(PluginV2.locationLayer.pipe(Layer.provide(EventV2.defaultLayer)))),
-)
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: GroqPlugin.id, effect: GroqPlugin.effect(host) })
+})
 
 describe("GroqPlugin", () => {
   it.effect("creates a Groq SDK for @ai-sdk/groq", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GroqPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("groq", "llama"), package: "@ai-sdk/groq", options: { name: "groq" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("groq"), ModelV2.ID.make("llama")),
+            api: { id: ModelV2.ID.make("llama"), type: "aisdk", package: "@ai-sdk/groq" },
+          }),
+          package: "@ai-sdk/groq",
+          options: { name: "groq" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -30,10 +41,17 @@ describe("GroqPlugin", () => {
   it.effect("ignores non-Groq SDK packages", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GroqPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("groq", "llama"), package: "@ai-sdk/openai-compatible", options: { name: "groq" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("groq"), ModelV2.ID.make("llama")),
+            api: { id: ModelV2.ID.make("llama"), type: "aisdk", package: "@ai-sdk/groq" },
+          }),
+          package: "@ai-sdk/openai-compatible",
+          options: { name: "groq" },
+        },
         {},
       )
       expect(result.sdk).toBeUndefined()
@@ -43,10 +61,17 @@ describe("GroqPlugin", () => {
   it.effect("only matches the bundled @ai-sdk/groq package exactly", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GroqPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("groq", "llama"), package: "@ai-sdk/groq/compat", options: { name: "groq" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("groq"), ModelV2.ID.make("llama")),
+            api: { id: ModelV2.ID.make("llama"), type: "aisdk", package: "@ai-sdk/groq" },
+          }),
+          package: "@ai-sdk/groq/compat",
+          options: { name: "groq" },
+        },
         {},
       )
       expect(result.sdk).toBeUndefined()
@@ -56,11 +81,14 @@ describe("GroqPlugin", () => {
   it.effect("matches the old bundled Groq SDK provider naming", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, GroqPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-groq", "llama"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-groq"), ModelV2.ID.make("llama")),
+            api: { id: ModelV2.ID.make("llama"), type: "aisdk", package: "@ai-sdk/groq" },
+          }),
           package: "@ai-sdk/groq",
           options: { name: "custom-groq", apiKey: "test" },
         },
@@ -75,26 +103,32 @@ describe("GroqPlugin", () => {
     }),
   )
 
-  aisdkIt.effect("uses the default languageModel(api.id) behavior", () =>
+  it.effect("uses the default languageModel(api.id) behavior", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      const aisdk = yield* AISDK.Service
-      yield* addPlugin(plugin, GroqPlugin)
-      const result = yield* aisdk.language(
-        model("groq", "alias", {
-          api: {
-            id: ModelV2.ID.make("llama-api"),
-            type: "aisdk",
-            package: "@ai-sdk/groq",
-          },
-          request: {
-            headers: {},
-            body: { apiKey: "test" },
-          },
-        }),
+      yield* addPlugin()
+      const sdk = createGroq({ name: "groq", apiKey: "test" } as Parameters<typeof createGroq>[0] & {
+        name: string
+      })
+      const result = yield* plugin.trigger(
+        "aisdk.language",
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("groq"), ModelV2.ID.make("alias")),
+            api: {
+              id: ModelV2.ID.make("llama-api"),
+              type: "aisdk",
+              package: "@ai-sdk/groq",
+            },
+          }),
+          sdk,
+          options: { name: "groq", apiKey: "test" },
+        },
+        {},
       )
-      expect(result.modelId).toBe("llama-api")
-      expect(result.provider).toBe("groq.chat")
+      const language = result.language ?? sdk.languageModel(result.model.api.id)
+      expect(language.modelId).toBe("llama-api")
+      expect(language.provider).toBe("groq.chat")
     }),
   )
 })

packages/core/test/plugin/provider-helper.ts

@@ -1,189 +0,0 @@
-import { Npm } from "@opencode-ai/core/npm"
-import type { Plugin } from "@opencode-ai/plugin/v2/effect"
-import type { LanguageModelV3 } from "@ai-sdk/provider"
-import { expect } from "bun:test"
-import { Effect, Layer, Option } from "effect"
-import { Catalog } from "@opencode-ai/core/catalog"
-import { Integration } from "@opencode-ai/core/integration"
-import { Credential } from "@opencode-ai/core/credential"
-import { EventV2 } from "@opencode-ai/core/event"
-import { Location } from "@opencode-ai/core/location"
-import { ModelV2 } from "@opencode-ai/core/model"
-import { PluginV2 } from "@opencode-ai/core/plugin"
-import { ProviderV2 } from "@opencode-ai/core/provider"
-import { AbsolutePath } from "@opencode-ai/core/schema"
-import { location } from "../fixture/location"
-import { testEffect } from "../lib/effect"
-import { aisdkHost, catalogHost, host, integrationHost } from "./host"
-
-export const fixtureProvider = new URL("./fixtures/provider-factory.ts", import.meta.url).href
-
-export function required<T>(value: T | undefined): T {
-  if (value === undefined) throw new Error("Expected value")
-  return value
-}
-
-const locationLayer = Layer.succeed(
-  Location.Service,
-  Location.Service.of(location({ directory: AbsolutePath.make("test") })),
-)
-
-export const npmLayer = Layer.succeed(
-  Npm.Service,
-  Npm.Service.of({
-    add: () => Effect.succeed({ directory: "", entrypoint: undefined }),
-    install: () => Effect.void,
-    which: () => Effect.succeed(undefined),
-  }),
-)
-
-export const catalogLayer = Layer.succeed(
-  Catalog.Service,
-  Catalog.Service.of({
-    transform: (_transform) => Effect.die("unexpected catalog.transform"),
-    rebuild: () => Effect.die("unexpected catalog.rebuild"),
-    provider: {
-      get: () => Effect.die("unexpected provider.get"),
-      all: () => Effect.succeed([]),
-      available: () => Effect.succeed([]),
-    },
-    model: {
-      get: () => Effect.die("unexpected model.get"),
-      all: () => Effect.succeed([]),
-      available: () => Effect.succeed([]),
-      default: () => Effect.succeed(undefined),
-      small: () => Effect.succeed(undefined),
-    },
-  }),
-)
-
-const integrations = Integration.locationLayer.pipe(
-  Layer.provide(EventV2.defaultLayer),
-  Layer.provide(
-    Layer.mock(Credential.Service)({
-      create: () => Effect.die("unexpected credential creation"),
-      all: () => Effect.succeed([]),
-      list: () => Effect.succeed([]),
-    }),
-  ),
-)
-
-export const it = testEffect(
-  Catalog.locationLayer.pipe(
-    Layer.provideMerge(integrations),
-    Layer.provideMerge(
-      Layer.mock(Credential.Service)({
-        all: () => Effect.succeed([]),
-      }),
-    ),
-    Layer.provideMerge(EventV2.defaultLayer),
-    Layer.provideMerge(locationLayer),
-    Layer.provideMerge(npmLayer),
-    Layer.provideMerge(PluginV2.locationLayer.pipe(Layer.provide(EventV2.defaultLayer))),
-  ),
-)
-
-export function addPlugin(plugin: PluginV2.Interface, definition: Plugin<any>) {
-  return Effect.gen(function* () {
-    const catalog = yield* Effect.serviceOption(Catalog.Service)
-    const integration = yield* Effect.serviceOption(Integration.Service)
-    const npm = yield* Effect.serviceOption(Npm.Service)
-    const effect =
-      typeof definition.effect === "function"
-        ? definition.effect(
-            host({
-              aisdk: aisdkHost(plugin),
-              ...(Option.isSome(catalog) ? { catalog: catalogHost(catalog.value) } : {}),
-              ...(Option.isSome(integration) ? { integration: integrationHost(integration.value) } : {}),
-              ...(Option.isSome(npm) ? { npm: npm.value } : {}),
-            }),
-          )
-        : definition.effect
-    yield* plugin.add({ id: definition.id, effect })
-  })
-}
-
-type ProviderInput = Partial<Omit<ProviderV2.Info, "api" | "request">> & {
-  api?: ProviderV2.Api
-  request?: ProviderV2.Request
-}
-
-type ModelInput = Partial<Omit<ModelV2.Info, "api" | "request">> & {
-  api?: (ProviderV2.Api & { id?: ModelV2.ID }) | { id: ModelV2.ID }
-  request?: ModelV2.Info["request"]
-}
-
-export function provider(providerID: string, options?: ProviderInput) {
-  return new ProviderV2.Info({
-    ...ProviderV2.Info.empty(ProviderV2.ID.make(providerID)),
-    api: options?.api ?? {
-      type: "aisdk",
-      package: "test-provider",
-    },
-    ...options,
-    request: {
-      headers: {},
-      body: {},
-      ...options?.request,
-    },
-  })
-}
-
-export function model(providerID: string, modelID: string, options?: ModelInput) {
-  return new ModelV2.Info({
-    ...ModelV2.Info.empty(ProviderV2.ID.make(providerID), ModelV2.ID.make(modelID)),
-    ...options,
-    api:
-      options?.api && "type" in options.api
-        ? { id: ModelV2.ID.make(modelID), ...options.api }
-        : {
-            id: ModelV2.ID.make(modelID),
-            ...options?.api,
-            type: "aisdk",
-            package: "test-provider",
-          },
-    request: {
-      headers: {},
-      body: {},
-      ...options?.request,
-    },
-  })
-}
-
-export function withEnv<A, E, R>(vars: Record<string, string | undefined>, fx: () => Effect.Effect<A, E, R>) {
-  return Effect.acquireUseRelease(
-    Effect.sync(() => {
-      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
-      for (const [key, value] of Object.entries(vars)) {
-        if (value === undefined) delete process.env[key]
-        else process.env[key] = value
-      }
-      return previous
-    }),
-    () => fx(),
-    (previous) =>
-      Effect.sync(() => {
-        for (const [key, value] of Object.entries(previous)) {
-          if (value === undefined) delete process.env[key]
-          else process.env[key] = value
-        }
-      }),
-  )
-}
-
-export function fakeSelectorSdk(calls: string[]) {
-  const make = (method: string) => (id: string) => {
-    calls.push(`${method}:${id}`)
-    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
-  }
-  return {
-    responses: make("responses"),
-    messages: make("messages"),
-    chat: make("chat"),
-    languageModel: make("languageModel"),
-  }
-}
-
-export function expectPluginRegistered(ids: string[], id: string) {
-  expect(ids).toContain(PluginV2.ID.make(id))
-}

packages/core/test/plugin/provider-kilo.test.ts

@@ -2,96 +2,98 @@ import { describe, expect } from "bun:test"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { ProviderPlugins } from "@opencode-ai/core/plugin/provider"
 import { KiloPlugin } from "@opencode-ai/core/plugin/provider/kilo"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, expectPluginRegistered, it, provider, required } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: KiloPlugin.id, effect: KiloPlugin.effect(host) })
+})
 
 describe("KiloPlugin", () => {
   it.effect("is registered so legacy referer headers can be applied", () =>
-    Effect.sync(() =>
-      expectPluginRegistered(
-        ProviderPlugins.map((item) => item.id),
-        "kilo",
-      ),
-    ),
+    Effect.sync(() => expect(ProviderPlugins.map((item) => item.id)).toContain(PluginV2.ID.make("kilo"))),
   )
 
   it.effect("applies legacy referer headers only to kilo", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, KiloPlugin)
       yield* catalog.transform((catalog) => {
-        const kilo = provider("kilo", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://api.kilo.ai/api/gateway" },
-          request: { headers: { Existing: "value" }, body: {} },
+        catalog.provider.update(ProviderV2.ID.make("kilo"), (provider) => {
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://api.kilo.ai/api/gateway",
+          }
+          provider.request = { headers: { Existing: "value" }, body: {} }
         })
-        catalog.provider.update(kilo.id, (draft) => {
-          draft.api = kilo.api
-          draft.request = kilo.request
-        })
-        catalog.provider.update(provider("openrouter").id, () => {})
+        catalog.provider.update(ProviderV2.ID.openrouter, () => {})
       })
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("kilo"))).request.headers).toEqual({
+      yield* addPlugin()
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("kilo")))?.request.headers).toEqual({
         Existing: "value",
         "HTTP-Referer": "https://opencode.ai/",
         "X-Title": "opencode",
       })
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.openrouter)).request.headers).toEqual({})
+      expect((yield* catalog.provider.get(ProviderV2.ID.openrouter))?.request.headers).toEqual({})
     }),
   )
 
   it.effect("uses the exact legacy Kilo header casing and set", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, KiloPlugin)
       yield* catalog.transform((catalog) => {
-        const item = provider("kilo", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://api.kilo.ai/api/gateway" },
-        })
-        catalog.provider.update(item.id, (draft) => {
-          draft.api = item.api
+        catalog.provider.update(ProviderV2.ID.make("kilo"), (provider) => {
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://api.kilo.ai/api/gateway",
+          }
         })
       })
+      yield* addPlugin()
 
-      const result = required(yield* catalog.provider.get(ProviderV2.ID.make("kilo")))
-      expect(result.request.headers).toEqual({
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("kilo")))?.request.headers).toEqual({
         "HTTP-Referer": "https://opencode.ai/",
         "X-Title": "opencode",
       })
-      expect(result.request.headers).not.toHaveProperty("http-referer")
-      expect(result.request.headers).not.toHaveProperty("x-title")
-      expect(result.request.headers).not.toHaveProperty("X-Source")
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("kilo")))?.request.headers).not.toHaveProperty(
+        "http-referer",
+      )
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("kilo")))?.request.headers).not.toHaveProperty("x-title")
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("kilo")))?.request.headers).not.toHaveProperty("X-Source")
     }),
   )
 
   it.effect("uses the legacy provider-id guard instead of endpoint package matching", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, KiloPlugin)
       yield* catalog.transform((catalog) => {
-        const kilo = provider("kilo", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://api.kilo.ai/api/gateway" },
+        catalog.provider.update(ProviderV2.ID.make("kilo"), (provider) => {
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://api.kilo.ai/api/gateway",
+          }
         })
-        catalog.provider.update(kilo.id, (draft) => {
-          draft.api = kilo.api
-        })
-        const custom = provider("custom-kilo", {
-          api: { type: "aisdk", package: "kilo" },
-        })
-        catalog.provider.update(custom.id, (draft) => {
-          draft.api = custom.api
+        catalog.provider.update(ProviderV2.ID.make("custom-kilo"), (provider) => {
+          provider.api = { type: "aisdk", package: "kilo" }
         })
       })
+      yield* addPlugin()
 
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("kilo"))).request.headers).toEqual({
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("kilo")))?.request.headers).toEqual({
         "HTTP-Referer": "https://opencode.ai/",
         "X-Title": "opencode",
       })
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("custom-kilo"))).request.headers).toEqual({})
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("custom-kilo")))?.request.headers).toEqual({})
     }),
   )
 })

packages/core/test/plugin/provider-llmgateway.test.ts

@@ -3,36 +3,28 @@ import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { Integration } from "@opencode-ai/core/integration"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { ProviderPlugins } from "@opencode-ai/core/plugin/provider"
 import { LLMGatewayPlugin } from "@opencode-ai/core/plugin/provider/llmgateway"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { expectPluginRegistered, it, provider, required } from "./provider-helper"
-import { catalogHost, host, integrationHost } from "./host"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: LLMGatewayPlugin.id, effect: LLMGatewayPlugin.effect(host) })
+})
 
 describe("LLMGatewayPlugin", () => {
-  const add = Effect.fnUntraced(function* (plugin: PluginV2.Interface) {
-    const integrations = yield* Integration.Service
-    const catalog = yield* Catalog.Service
-    yield* plugin.add({
-      ...LLMGatewayPlugin,
-      effect: LLMGatewayPlugin.effect(
-        host({ catalog: catalogHost(catalog), integration: integrationHost(integrations) }),
-      ),
-    })
-  })
-
   it.effect("is registered so legacy referer headers can be applied", () =>
-    Effect.sync(() =>
-      expectPluginRegistered(
-        ProviderPlugins.map((item) => item.id),
-        "llmgateway",
-      ),
-    ),
+    Effect.sync(() => expect(ProviderPlugins.map((item) => item.id)).toContain(PluginV2.ID.make("llmgateway"))),
   )
 
   it.effect("applies legacy referer headers only to enabled llmgateway", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
       const integrations = yield* Integration.Service
       yield* integrations.transform((editor) => {
@@ -40,43 +32,48 @@ describe("LLMGatewayPlugin", () => {
         editor.update(Integration.ID.make("openrouter"), () => {})
       })
       yield* catalog.transform((catalog) => {
-        const llmgateway = provider("llmgateway", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://api.llmgateway.io/v1" },
-          request: { headers: { Existing: "value" }, body: {} },
-        })
-        catalog.provider.update(llmgateway.id, (draft) => {
-          draft.api = llmgateway.api
-          draft.request = llmgateway.request
+        catalog.provider.update(ProviderV2.ID.make("llmgateway"), (provider) => {
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://api.llmgateway.io/v1",
+          }
+          provider.request = { headers: { Existing: "value" }, body: {} }
         })
         catalog.provider.update(ProviderV2.ID.openrouter, () => {})
       })
-      yield* add(plugin)
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("llmgateway"))).request.headers).toEqual({
+      yield* addPlugin()
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("llmgateway")))?.request.headers).toEqual({
         Existing: "value",
         "HTTP-Referer": "https://opencode.ai/",
         "X-Title": "opencode",
         "X-Source": "opencode",
       })
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.openrouter)).request.headers).toEqual({})
+      expect((yield* catalog.provider.get(ProviderV2.ID.openrouter))?.request.headers).toEqual({})
     }),
   )
 
   it.effect("does not apply legacy headers to a disabled llmgateway provider", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* add(plugin)
+      const integrations = yield* Integration.Service
+      yield* integrations.transform((editor) => {
+        editor.update(Integration.ID.make("llmgateway"), () => {})
+      })
       yield* catalog.transform((catalog) => {
-        const item = provider("llmgateway", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://api.llmgateway.io/v1" },
-        })
-        catalog.provider.update(item.id, (draft) => {
-          draft.api = item.api
+        catalog.provider.update(ProviderV2.ID.make("llmgateway"), (provider) => {
+          provider.disabled = true
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://api.llmgateway.io/v1",
+          }
         })
       })
+      yield* addPlugin()
 
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("llmgateway"))).disabled).toBeUndefined()
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("llmgateway"))).request.headers).toEqual({})
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("llmgateway")))?.disabled).toBe(true)
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("llmgateway")))?.request.headers).toEqual({})
     }),
   )
 })

packages/core/test/plugin/provider-mistral.test.ts

@@ -1,18 +1,37 @@
+import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { describe, expect } from "bun:test"
 import { Effect } from "effect"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { MistralPlugin } from "@opencode-ai/core/plugin/provider/mistral"
-import { addPlugin, fakeSelectorSdk, it, model } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: MistralPlugin.id, effect: MistralPlugin.effect(host) })
+})
 
 describe("MistralPlugin", () => {
   it.effect("creates a Mistral SDK for @ai-sdk/mistral", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, MistralPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("mistral", "mistral-large"), package: "@ai-sdk/mistral", options: { name: "mistral" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("mistral"), ModelV2.ID.make("mistral-large")),
+            api: { id: ModelV2.ID.make("mistral-large"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/mistral",
+          options: { name: "mistral" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -22,11 +41,14 @@ describe("MistralPlugin", () => {
   it.effect("ignores non-Mistral SDK packages", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, MistralPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("mistral", "mistral-large"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("mistral"), ModelV2.ID.make("mistral-large")),
+            api: { id: ModelV2.ID.make("mistral-large"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/openai-compatible",
           options: { name: "mistral" },
         },
@@ -40,19 +62,22 @@ describe("MistralPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const providers: string[] = []
-      yield* addPlugin(plugin, MistralPlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("mistral-sdk-inspector"),
-        effect: Effect.succeed({
-          "aisdk.sdk": (evt) =>
-            Effect.sync(() => {
-              providers.push(evt.sdk.languageModel("mistral-large").provider)
-            }),
+      yield* addPlugin()
+      yield* plugin.hook("aisdk.sdk", (event) =>
+        Effect.sync(() => {
+          providers.push(event.sdk.languageModel("mistral-large").provider)
         }),
-      })
+      )
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("mistral", "mistral-large"), package: "@ai-sdk/mistral", options: { name: "mistral" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("mistral"), ModelV2.ID.make("mistral-large")),
+            api: { id: ModelV2.ID.make("mistral-large"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/mistral",
+          options: { name: "mistral" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -64,20 +89,19 @@ describe("MistralPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const providers: string[] = []
-      yield* addPlugin(plugin, MistralPlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("mistral-sdk-inspector"),
-        effect: Effect.succeed({
-          "aisdk.sdk": (evt) =>
-            Effect.sync(() => {
-              providers.push(evt.sdk.languageModel("mistral-large").provider)
-            }),
+      yield* addPlugin()
+      yield* plugin.hook("aisdk.sdk", (event) =>
+        Effect.sync(() => {
+          providers.push(event.sdk.languageModel("mistral-large").provider)
         }),
-      })
+      )
       yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-mistral", "mistral-large"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-mistral"), ModelV2.ID.make("mistral-large")),
+            api: { id: ModelV2.ID.make("mistral-large"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/mistral",
           options: { name: "custom-mistral" },
         },
@@ -91,11 +115,23 @@ describe("MistralPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      const sdk = fakeSelectorSdk(calls)
-      yield* addPlugin(plugin, MistralPlugin)
+      const sdk = {
+        languageModel: (id: string) => {
+          calls.push(`languageModel:${id}`)
+          return { modelId: id, provider: "languageModel", specificationVersion: "v3" } as unknown as LanguageModelV3
+        },
+      }
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
-        { model: model("mistral", "alias", { api: { id: ModelV2.ID.make("mistral-large") } }), sdk, options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("mistral"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("mistral-large"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk,
+          options: {},
+        },
         {},
       )
       const language = result.language ?? sdk.languageModel(result.model.api.id)

packages/core/test/plugin/provider-nvidia.test.ts

@@ -2,64 +2,66 @@ import { describe, expect } from "bun:test"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { ProviderPlugins } from "@opencode-ai/core/plugin/provider"
 import { NvidiaPlugin } from "@opencode-ai/core/plugin/provider/nvidia"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, expectPluginRegistered, it, provider, required } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: NvidiaPlugin.id, effect: NvidiaPlugin.effect(host) })
+})
 
 describe("NvidiaPlugin", () => {
   it.effect("is registered so legacy referer headers can be applied", () =>
-    Effect.sync(() =>
-      expectPluginRegistered(
-        ProviderPlugins.map((item) => item.id),
-        "nvidia",
-      ),
-    ),
+    Effect.sync(() => expect(ProviderPlugins.map((item) => item.id)).toContain(PluginV2.ID.make("nvidia"))),
   )
 
   it.effect("applies NVIDIA tracking headers only to nvidia", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, NvidiaPlugin)
       yield* catalog.transform((catalog) => {
-        const nvidia = provider("nvidia", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://integrate.api.nvidia.com/v1" },
-          request: { headers: { Existing: "value" }, body: {} },
+        catalog.provider.update(ProviderV2.ID.make("nvidia"), (provider) => {
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://integrate.api.nvidia.com/v1",
+          }
+          provider.request = { headers: { Existing: "value" }, body: {} }
         })
-        catalog.provider.update(nvidia.id, (draft) => {
-          draft.api = nvidia.api
-          draft.request = nvidia.request
-        })
-        catalog.provider.update(provider("openrouter").id, () => {})
+        catalog.provider.update(ProviderV2.ID.openrouter, () => {})
       })
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("nvidia"))).request.headers).toEqual({
+      yield* addPlugin()
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("nvidia")))?.request.headers).toEqual({
         Existing: "value",
         "HTTP-Referer": "https://opencode.ai/",
         "X-Title": "opencode",
         "X-BILLING-INVOKE-ORIGIN": "OpenCode",
       })
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.openrouter)).request.headers).toEqual({})
+      expect((yield* catalog.provider.get(ProviderV2.ID.openrouter))?.request.headers).toEqual({})
     }),
   )
 
   it.effect("adds billing origin for custom NVIDIA endpoints", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, NvidiaPlugin)
       yield* catalog.transform((catalog) => {
-        const item = provider("nvidia", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://integrate.api.nvidia.com/v1" },
-          request: { headers: {}, body: {} },
-        })
-        catalog.provider.update(item.id, (draft) => {
-          draft.api = item.api
-          draft.request = item.request
+        catalog.provider.update(ProviderV2.ID.make("nvidia"), (provider) => {
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://integrate.api.nvidia.com/v1",
+          }
         })
       })
+      yield* addPlugin()
 
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("nvidia"))).request.headers).toEqual({
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("nvidia")))?.request.headers).toEqual({
         "HTTP-Referer": "https://opencode.ai/",
         "X-Title": "opencode",
         "X-BILLING-INVOKE-ORIGIN": "OpenCode",
@@ -69,24 +71,23 @@ describe("NvidiaPlugin", () => {
 
   it.effect("preserves an explicit NVIDIA billing origin header", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, NvidiaPlugin)
       yield* catalog.transform((catalog) => {
-        const item = provider("nvidia", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://integrate.api.nvidia.com/v1" },
-          request: {
+        catalog.provider.update(ProviderV2.ID.make("nvidia"), (provider) => {
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://integrate.api.nvidia.com/v1",
+          }
+          provider.request = {
             headers: { "X-BILLING-INVOKE-ORIGIN": "CustomOrigin" },
             body: { baseURL: "https://integrate.api.nvidia.com/v1" },
-          },
-        })
-        catalog.provider.update(item.id, (draft) => {
-          draft.api = item.api
-          draft.request = item.request
+          }
         })
       })
+      yield* addPlugin()
 
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("nvidia"))).request.headers).toEqual({
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("nvidia")))?.request.headers).toEqual({
         "HTTP-Referer": "https://opencode.ai/",
         "X-Title": "opencode",
         "X-BILLING-INVOKE-ORIGIN": "CustomOrigin",

packages/core/test/plugin/provider-openai-compatible.test.ts

@@ -1,23 +1,45 @@
 import { describe, expect } from "bun:test"
 import { Effect } from "effect"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { OpenAICompatiblePlugin } from "@opencode-ai/core/plugin/provider/openai-compatible"
-import { addPlugin, it, model } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: OpenAICompatiblePlugin.id, effect: OpenAICompatiblePlugin.effect(host) })
+})
 
 describe("OpenAICompatiblePlugin", () => {
   it.effect("preserves explicit includeUsage false and defaults it to true", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, OpenAICompatiblePlugin)
+      yield* addPlugin()
       const defaulted = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("custom", "model"), package: "@ai-sdk/openai-compatible", options: { name: "custom" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/openai-compatible",
+          options: { name: "custom" },
+        },
         {},
       )
       const disabled = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom", "model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/openai-compatible",
           options: { name: "custom", includeUsage: false },
         },
@@ -31,11 +53,14 @@ describe("OpenAICompatiblePlugin", () => {
   it.effect("defaults includeUsage for OpenAI-compatible package matches", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, OpenAICompatiblePlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom", "model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
           package: "file:///tmp/@ai-sdk/openai-compatible-provider.js",
           options: { name: "custom" },
         },
@@ -49,20 +74,19 @@ describe("OpenAICompatiblePlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const observed: string[] = []
-      yield* addPlugin(plugin, OpenAICompatiblePlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("inspector"),
-        effect: Effect.succeed({
-          "aisdk.sdk": (evt) =>
-            Effect.sync(() => {
-              observed.push(evt.sdk.languageModel("model").provider)
-            }),
+      yield* addPlugin()
+      yield* plugin.hook("aisdk.sdk", (event) =>
+        Effect.sync(() => {
+          observed.push(event.sdk.languageModel("model").provider)
         }),
-      })
+      )
       yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-provider", "model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-provider"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/openai-compatible",
           options: { name: "custom-provider", baseURL: "https://example.com/v1" },
         },
@@ -85,11 +109,14 @@ describe("OpenAICompatiblePlugin", () => {
             }),
         }),
       })
-      yield* addPlugin(plugin, OpenAICompatiblePlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("cloudflare-workers-ai", "model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("cloudflare-workers-ai"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/openai-compatible",
           options: { name: "cloudflare-workers-ai" },
         },

packages/core/test/plugin/provider-openai.test.ts

@@ -1,28 +1,50 @@
 import { describe, expect } from "bun:test"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { Integration } from "@opencode-ai/core/integration"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { OpenAIPlugin } from "@opencode-ai/core/plugin/provider/openai"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { fakeSelectorSdk, it, model, provider, required } from "./provider-helper"
-import { host, integrationHost } from "./host"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
 
-function add(plugin: PluginV2.Interface, integrations: Integration.Interface) {
-  return plugin.add({
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  const integrations = yield* Integration.Service
+  yield* plugin.add({
     id: OpenAIPlugin.id,
-    effect: OpenAIPlugin.effect(host({ integration: integrationHost(integrations) })).pipe(
-      Effect.provideService(Integration.Service, integrations),
-    ),
+    effect: OpenAIPlugin.effect(host).pipe(Effect.provideService(Integration.Service, integrations)),
   })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
 }
 
 describe("OpenAIPlugin", () => {
   it.effect("registers browser and headless ChatGPT OAuth methods", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
-      yield* add(plugin, yield* Integration.Service)
+      yield* addPlugin()
       expect((yield* (yield* Integration.Service).get(Integration.ID.make("openai")))?.methods).toEqual([
         {
           id: Integration.MethodID.make("chatgpt-browser"),
@@ -41,11 +63,14 @@ describe("OpenAIPlugin", () => {
   it.effect("creates an OpenAI SDK for @ai-sdk/openai using the provider ID as SDK name", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* add(plugin, yield* Integration.Service)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-openai", "gpt-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-openai"), ModelV2.ID.make("gpt-5")),
+            api: { id: ModelV2.ID.make("gpt-5"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/openai",
           options: { name: "custom-openai", apiKey: "test" },
         },
@@ -58,10 +83,17 @@ describe("OpenAIPlugin", () => {
   it.effect("ignores non-OpenAI SDK packages", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* add(plugin, yield* Integration.Service)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("openai", "gpt-5"), package: "@ai-sdk/openai-compatible", options: { name: "openai" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.openai, ModelV2.ID.make("gpt-5")),
+            api: { id: ModelV2.ID.make("gpt-5"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/openai-compatible",
+          options: { name: "openai" },
+        },
         {},
       )
       expect(result.sdk).toBeUndefined()
@@ -72,11 +104,12 @@ describe("OpenAIPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* add(plugin, yield* Integration.Service)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("openai", "alias", {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.openai, ModelV2.ID.make("alias")),
             api: { id: ModelV2.ID.make("gpt-5"), type: "aisdk", package: "test-provider" },
           }),
           sdk: fakeSelectorSdk(calls),
@@ -93,10 +126,17 @@ describe("OpenAIPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* add(plugin, yield* Integration.Service)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
-        { model: model("anthropic", "gpt-5"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.anthropic, ModelV2.ID.make("gpt-5")),
+            api: { id: ModelV2.ID.make("gpt-5"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       expect(calls).toEqual([])
@@ -106,17 +146,19 @@ describe("OpenAIPlugin", () => {
 
   it.effect("disables gpt-5-chat-latest during catalog transforms", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* add(plugin, yield* Integration.Service)
       yield* catalog.transform((catalog) => {
-        const item = provider("openai", { api: { type: "aisdk", package: "@ai-sdk/openai" } })
+        const item = new ProviderV2.Info({
+          ...ProviderV2.Info.empty(ProviderV2.ID.openai),
+          api: { type: "aisdk", package: "@ai-sdk/openai" },
+        })
         catalog.provider.update(item.id, (draft) => {
           draft.api = item.api
         })
         catalog.model.update(item.id, ModelV2.ID.make("gpt-5"), () => {})
         catalog.model.update(item.id, ModelV2.ID.make("gpt-5-chat-latest"), () => {})
       })
+      yield* addPlugin()
       expect(required(yield* catalog.model.get(ProviderV2.ID.openai, ModelV2.ID.make("gpt-5"))).enabled).toBe(true)
       expect(
         required(yield* catalog.model.get(ProviderV2.ID.openai, ModelV2.ID.make("gpt-5-chat-latest"))).enabled,
@@ -126,14 +168,18 @@ describe("OpenAIPlugin", () => {
 
   it.effect("does not disable gpt-5-chat-latest for non-OpenAI providers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* add(plugin, yield* Integration.Service)
       yield* catalog.transform((catalog) => {
-        const item = provider("custom-openai")
-        catalog.provider.update(item.id, () => {})
+        const item = new ProviderV2.Info({
+          ...ProviderV2.Info.empty(ProviderV2.ID.make("custom-openai")),
+          api: { type: "aisdk", package: "test-provider" },
+        })
+        catalog.provider.update(item.id, (draft) => {
+          draft.api = item.api
+        })
         catalog.model.update(item.id, ModelV2.ID.make("gpt-5-chat-latest"), () => {})
       })
+      yield* addPlugin()
       expect(
         required(yield* catalog.model.get(ProviderV2.ID.make("custom-openai"), ModelV2.ID.make("gpt-5-chat-latest")))
           .enabled,

packages/core/test/plugin/provider-opencode.test.ts

@@ -1,45 +1,72 @@
 import { describe, expect } from "bun:test"
-import { Effect, Layer, Option } from "effect"
+import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
-import { Credential } from "@opencode-ai/core/credential"
-import { EventV2 } from "@opencode-ai/core/event"
 import { Integration } from "@opencode-ai/core/integration"
-import { Location } from "@opencode-ai/core/location"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { OpencodePlugin } from "@opencode-ai/core/plugin/provider/opencode"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { AbsolutePath } from "@opencode-ai/core/schema"
-import { location } from "../fixture/location"
-import { it, model, provider, required, withEnv } from "./provider-helper"
-import { catalogHost, host, integrationHost } from "./host"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: OpencodePlugin.id, effect: OpencodePlugin.effect(host) })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, effect: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    effect,
+    (previous) =>
+      Effect.sync(() =>
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        }),
+      ),
+  )
+}
 
 const cost = (input: number, output = 0) => [{ input, output, cache: { read: 0, write: 0 } }]
-const locationLayer = Layer.succeed(
-  Location.Service,
-  Location.Service.of(location({ directory: AbsolutePath.make("test") })),
-)
-
-const pluginWithIntegrations = (catalog: Catalog.Interface, integrations: Integration.Interface) => ({
-  ...OpencodePlugin,
-  effect: OpencodePlugin.effect(host({ catalog: catalogHost(catalog), integration: integrationHost(integrations) })),
-})
 
 describe("OpencodePlugin", () => {
   it.effect("uses a public key and disables paid models without credentials", () =>
     withEnv({ OPENCODE_API_KEY: undefined }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
-        yield* plugin.add(pluginWithIntegrations(catalog, yield* Integration.Service))
         yield* catalog.transform((catalog) => {
-          const item = provider("opencode")
-          catalog.provider.update(item.id, () => {})
-          const paid = model("opencode", "paid", { cost: cost(1) })
-          catalog.model.update(item.id, paid.id, (draft) => {
-            draft.cost = [...paid.cost]
+          const provider = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.opencode),
+            api: { type: "aisdk", package: "test-provider" },
+          })
+          const model = new ModelV2.Info({
+            ...ModelV2.Info.empty(provider.id, ModelV2.ID.make("paid")),
+            api: { id: ModelV2.ID.make("paid"), type: "aisdk", package: "test-provider" },
+            cost: cost(1),
+          })
+          catalog.provider.update(provider.id, () => {})
+          catalog.model.update(provider.id, model.id, (draft) => {
+            draft.cost = [...model.cost]
           })
         })
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.opencode)).request.body.apiKey).toBe("public")
         expect(required(yield* catalog.model.get(ProviderV2.ID.opencode, ModelV2.ID.make("paid"))).enabled).toBe(false)
       }),
@@ -49,17 +76,23 @@ describe("OpencodePlugin", () => {
   it.effect("keeps free models without credentials", () =>
     withEnv({ OPENCODE_API_KEY: undefined }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
-        yield* plugin.add(pluginWithIntegrations(catalog, yield* Integration.Service))
         yield* catalog.transform((catalog) => {
-          const item = provider("opencode")
-          catalog.provider.update(item.id, () => {})
-          const free = model("opencode", "free", { cost: cost(0) })
-          catalog.model.update(item.id, free.id, (draft) => {
-            draft.cost = [...free.cost]
+          const provider = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.opencode),
+            api: { type: "aisdk", package: "test-provider" },
+          })
+          const model = new ModelV2.Info({
+            ...ModelV2.Info.empty(provider.id, ModelV2.ID.make("free")),
+            api: { id: ModelV2.ID.make("free"), type: "aisdk", package: "test-provider" },
+            cost: cost(0),
+          })
+          catalog.provider.update(provider.id, () => {})
+          catalog.model.update(provider.id, model.id, (draft) => {
+            draft.cost = [...model.cost]
           })
         })
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.opencode)).request.body.apiKey).toBe("public")
         expect(required(yield* catalog.model.get(ProviderV2.ID.opencode, ModelV2.ID.make("free"))).enabled).toBe(true)
       }),
@@ -69,17 +102,23 @@ describe("OpencodePlugin", () => {
   it.effect("treats output-only cost as free without credentials", () =>
     withEnv({ OPENCODE_API_KEY: undefined }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
-        yield* plugin.add(pluginWithIntegrations(catalog, yield* Integration.Service))
         yield* catalog.transform((catalog) => {
-          const item = provider("opencode")
-          catalog.provider.update(item.id, () => {})
-          const outputOnly = model("opencode", "output-only", { cost: cost(0, 1) })
-          catalog.model.update(item.id, outputOnly.id, (draft) => {
-            draft.cost = [...outputOnly.cost]
+          const provider = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.opencode),
+            api: { type: "aisdk", package: "test-provider" },
+          })
+          const model = new ModelV2.Info({
+            ...ModelV2.Info.empty(provider.id, ModelV2.ID.make("output-only")),
+            api: { id: ModelV2.ID.make("output-only"), type: "aisdk", package: "test-provider" },
+            cost: cost(0, 1),
+          })
+          catalog.provider.update(provider.id, () => {})
+          catalog.model.update(provider.id, model.id, (draft) => {
+            draft.cost = [...model.cost]
           })
         })
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.opencode)).request.body.apiKey).toBe("public")
         expect(required(yield* catalog.model.get(ProviderV2.ID.opencode, ModelV2.ID.make("output-only"))).enabled).toBe(
           true,
@@ -91,17 +130,23 @@ describe("OpencodePlugin", () => {
   it.effect("uses OPENCODE_API_KEY as credentials", () =>
     withEnv({ OPENCODE_API_KEY: "secret" }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
-        yield* plugin.add(pluginWithIntegrations(catalog, yield* Integration.Service))
         yield* catalog.transform((catalog) => {
-          const item = provider("opencode")
-          catalog.provider.update(item.id, () => {})
-          const paid = model("opencode", "paid", { cost: cost(1) })
-          catalog.model.update(item.id, paid.id, (draft) => {
-            draft.cost = [...paid.cost]
+          const provider = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.opencode),
+            api: { type: "aisdk", package: "test-provider" },
+          })
+          const model = new ModelV2.Info({
+            ...ModelV2.Info.empty(provider.id, ModelV2.ID.make("paid")),
+            api: { id: ModelV2.ID.make("paid"), type: "aisdk", package: "test-provider" },
+            cost: cost(1),
+          })
+          catalog.provider.update(provider.id, () => {})
+          catalog.model.update(provider.id, model.id, (draft) => {
+            draft.cost = [...model.cost]
           })
         })
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.opencode)).request.body.apiKey).toBeUndefined()
         expect(required(yield* catalog.model.get(ProviderV2.ID.opencode, ModelV2.ID.make("paid"))).enabled).toBe(true)
       }),
@@ -111,10 +156,8 @@ describe("OpencodePlugin", () => {
   it.effect("uses configured provider env vars as credentials", () =>
     withEnv({ OPENCODE_API_KEY: undefined, CUSTOM_OPENCODE_API_KEY: "secret" }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
         const integrations = yield* Integration.Service
-        yield* plugin.add(pluginWithIntegrations(catalog, integrations))
         yield* integrations.transform((editor) => {
           editor.method.update({
             integrationID: Integration.ID.make("opencode"),
@@ -122,13 +165,21 @@ describe("OpencodePlugin", () => {
           })
         })
         yield* catalog.transform((catalog) => {
-          const item = provider("opencode")
-          catalog.provider.update(item.id, () => {})
-          const paid = model("opencode", "paid", { cost: cost(1) })
-          catalog.model.update(item.id, paid.id, (draft) => {
-            draft.cost = [...paid.cost]
+          const provider = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.opencode),
+            api: { type: "aisdk", package: "test-provider" },
+          })
+          const model = new ModelV2.Info({
+            ...ModelV2.Info.empty(provider.id, ModelV2.ID.make("paid")),
+            api: { id: ModelV2.ID.make("paid"), type: "aisdk", package: "test-provider" },
+            cost: cost(1),
+          })
+          catalog.provider.update(provider.id, () => {})
+          catalog.model.update(provider.id, model.id, (draft) => {
+            draft.cost = [...model.cost]
           })
         })
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.opencode)).request.body.apiKey).toBeUndefined()
         expect(required(yield* catalog.model.get(ProviderV2.ID.opencode, ModelV2.ID.make("paid"))).enabled).toBe(true)
       }),
@@ -138,24 +189,29 @@ describe("OpencodePlugin", () => {
   it.effect("uses configured apiKey as credentials", () =>
     withEnv({ OPENCODE_API_KEY: undefined }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
-        yield* plugin.add(pluginWithIntegrations(catalog, yield* Integration.Service))
         yield* catalog.transform((catalog) => {
-          const item = provider("opencode", {
+          const provider = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.opencode),
+            api: { type: "aisdk", package: "test-provider" },
             request: {
               headers: {},
               body: { apiKey: "configured" },
             },
           })
-          catalog.provider.update(item.id, (draft) => {
-            draft.request = item.request
+          const model = new ModelV2.Info({
+            ...ModelV2.Info.empty(provider.id, ModelV2.ID.make("paid")),
+            api: { id: ModelV2.ID.make("paid"), type: "aisdk", package: "test-provider" },
+            cost: cost(1),
           })
-          const paid = model("opencode", "paid", { cost: cost(1) })
-          catalog.model.update(item.id, paid.id, (draft) => {
-            draft.cost = [...paid.cost]
+          catalog.provider.update(provider.id, (draft) => {
+            draft.request = provider.request
+          })
+          catalog.model.update(provider.id, model.id, (draft) => {
+            draft.cost = [...model.cost]
           })
         })
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.opencode)).request.body.apiKey).toBe("configured")
         expect(required(yield* catalog.model.get(ProviderV2.ID.opencode, ModelV2.ID.make("paid"))).enabled).toBe(true)
       }),
@@ -165,17 +221,23 @@ describe("OpencodePlugin", () => {
   it.effect("ignores non-opencode providers and models", () =>
     withEnv({ OPENCODE_API_KEY: undefined }, () =>
       Effect.gen(function* () {
-        const plugin = yield* PluginV2.Service
         const catalog = yield* Catalog.Service
-        yield* plugin.add(pluginWithIntegrations(catalog, yield* Integration.Service))
         yield* catalog.transform((catalog) => {
-          const item = provider("openai")
-          catalog.provider.update(item.id, () => {})
-          const paid = model("openai", "paid", { cost: cost(1) })
-          catalog.model.update(item.id, paid.id, (draft) => {
-            draft.cost = [...paid.cost]
+          const provider = new ProviderV2.Info({
+            ...ProviderV2.Info.empty(ProviderV2.ID.openai),
+            api: { type: "aisdk", package: "test-provider" },
+          })
+          const model = new ModelV2.Info({
+            ...ModelV2.Info.empty(provider.id, ModelV2.ID.make("paid")),
+            api: { id: ModelV2.ID.make("paid"), type: "aisdk", package: "test-provider" },
+            cost: cost(1),
+          })
+          catalog.provider.update(provider.id, () => {})
+          catalog.model.update(provider.id, model.id, (draft) => {
+            draft.cost = [...model.cost]
           })
         })
+        yield* addPlugin()
         expect(required(yield* catalog.provider.get(ProviderV2.ID.openai)).request.body.apiKey).toBeUndefined()
         expect(required(yield* catalog.model.get(ProviderV2.ID.openai, ModelV2.ID.make("paid"))).enabled).toBe(true)
       }),
@@ -206,8 +268,6 @@ describe("OpencodePlugin", () => {
       const selected = yield* catalog.model.small(providerID)
 
       expect(selected?.id).toBe(ModelV2.ID.make("gpt-5-nano"))
-    }).pipe(
-      Effect.provide(Catalog.locationLayer.pipe(Layer.provide(EventV2.defaultLayer), Layer.provide(locationLayer))),
-    ),
+    }),
   )
 })

packages/core/test/plugin/provider-openrouter.test.ts

@@ -3,56 +3,59 @@ import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { ProviderPlugins } from "@opencode-ai/core/plugin/provider"
 import { OpenRouterPlugin } from "@opencode-ai/core/plugin/provider/openrouter"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, expectPluginRegistered, it, model, provider, required } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: OpenRouterPlugin.id, effect: OpenRouterPlugin.effect(host) })
+})
 
 describe("OpenRouterPlugin", () => {
   it.effect("is registered so legacy OpenRouter behavior can be applied", () =>
-    Effect.sync(() =>
-      expectPluginRegistered(
-        ProviderPlugins.map((item) => item.id),
-        "openrouter",
-      ),
-    ),
+    Effect.sync(() => expect(ProviderPlugins.map((item) => item.id)).toContain(PluginV2.ID.make("openrouter"))),
   )
 
   it.effect("applies legacy referer headers only to openrouter", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, OpenRouterPlugin)
       yield* catalog.transform((catalog) => {
-        const openrouter = provider("openrouter", {
-          api: { type: "aisdk", package: "@openrouter/ai-sdk-provider" },
-          request: { headers: { Existing: "value" }, body: {} },
-        })
-        catalog.provider.update(openrouter.id, (item) => {
-          item.api = openrouter.api
-          item.request = openrouter.request
+        catalog.provider.update(ProviderV2.ID.openrouter, (provider) => {
+          provider.api = { type: "aisdk", package: "@openrouter/ai-sdk-provider" }
+          provider.request = { headers: { Existing: "value" }, body: {} }
         })
         catalog.provider.update(ProviderV2.ID.make("nvidia"), () => {})
       })
+      yield* addPlugin()
 
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("openrouter"))).request.headers).toEqual({
+      expect((yield* catalog.provider.get(ProviderV2.ID.openrouter))?.request.headers).toEqual({
         Existing: "value",
         "HTTP-Referer": "https://opencode.ai/",
         "X-Title": "opencode",
       })
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("nvidia"))).request.headers).toEqual({})
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("nvidia")))?.request.headers).toEqual({})
     }),
   )
 
   it.effect("creates an SDK only for the OpenRouter package", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, OpenRouterPlugin)
+      yield* addPlugin()
 
       const ignored = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("openrouter", "openai/gpt-5"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.openrouter, ModelV2.ID.make("openai/gpt-5")),
+            api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/openai-compatible",
           options: { name: "openrouter" },
         },
@@ -62,7 +65,14 @@ describe("OpenRouterPlugin", () => {
 
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("custom", "openai/gpt-5"), package: "@openrouter/ai-sdk-provider", options: { name: "custom" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom"), ModelV2.ID.make("openai/gpt-5")),
+            api: { id: ModelV2.ID.make("openai/gpt-5"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@openrouter/ai-sdk-provider",
+          options: { name: "custom" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -71,52 +81,37 @@ describe("OpenRouterPlugin", () => {
 
   it.effect("filters OpenRouter's gpt-5 chat alias", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, OpenRouterPlugin)
       yield* catalog.transform((catalog) => {
-        const openrouter = provider("openrouter", {
-          api: { type: "aisdk", package: "@openrouter/ai-sdk-provider" },
-        })
-        catalog.provider.update(openrouter.id, (item) => {
-          item.api = openrouter.api
+        catalog.provider.update(ProviderV2.ID.openrouter, (provider) => {
+          provider.api = { type: "aisdk", package: "@openrouter/ai-sdk-provider" }
         })
         catalog.provider.update(ProviderV2.ID.openai, () => {})
-        for (const item of [
-          model("openrouter", "openai/gpt-5-chat"),
-          model("openrouter", "openai/gpt-5"),
-          model("openai", "openai/gpt-5-chat"),
-        ]) {
-          catalog.model.update(item.providerID, item.id, () => {})
-        }
+        catalog.model.update(ProviderV2.ID.openrouter, ModelV2.ID.make("openai/gpt-5-chat"), () => {})
+        catalog.model.update(ProviderV2.ID.openrouter, ModelV2.ID.make("openai/gpt-5"), () => {})
+        catalog.model.update(ProviderV2.ID.openai, ModelV2.ID.make("openai/gpt-5-chat"), () => {})
       })
+      yield* addPlugin()
 
-      expect(
-        required(yield* catalog.model.get(ProviderV2.ID.make("openrouter"), ModelV2.ID.make("openai/gpt-5-chat")))
-          .enabled,
-      ).toBe(false)
-      expect(
-        required(yield* catalog.model.get(ProviderV2.ID.make("openrouter"), ModelV2.ID.make("openai/gpt-5"))).enabled,
-      ).toBe(true)
-      expect(
-        required(yield* catalog.model.get(ProviderV2.ID.openai, ModelV2.ID.make("openai/gpt-5-chat"))).enabled,
-      ).toBe(true)
+      expect((yield* catalog.model.get(ProviderV2.ID.openrouter, ModelV2.ID.make("openai/gpt-5-chat")))?.enabled).toBe(
+        false,
+      )
+      expect((yield* catalog.model.get(ProviderV2.ID.openrouter, ModelV2.ID.make("openai/gpt-5")))?.enabled).toBe(true)
+      expect((yield* catalog.model.get(ProviderV2.ID.openai, ModelV2.ID.make("openai/gpt-5-chat")))?.enabled).toBe(true)
     }),
   )
 
   it.effect("does not disable gpt-5-chat-latest for non-OpenRouter providers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, OpenRouterPlugin)
       yield* catalog.transform((catalog) => {
         catalog.provider.update(ProviderV2.ID.make("custom-openrouter"), () => {})
         catalog.model.update(ProviderV2.ID.make("custom-openrouter"), ModelV2.ID.make("gpt-5-chat-latest"), () => {})
       })
+      yield* addPlugin()
       expect(
-        required(
-          yield* catalog.model.get(ProviderV2.ID.make("custom-openrouter"), ModelV2.ID.make("gpt-5-chat-latest")),
-        ).enabled,
+        (yield* catalog.model.get(ProviderV2.ID.make("custom-openrouter"), ModelV2.ID.make("gpt-5-chat-latest")))
+          ?.enabled,
       ).toBe(true)
     }),
   )

packages/core/test/plugin/provider-perplexity.test.ts

@@ -1,18 +1,50 @@
 import { describe, expect } from "bun:test"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { Effect } from "effect"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { PerplexityPlugin } from "@opencode-ai/core/plugin/provider/perplexity"
-import { addPlugin, fakeSelectorSdk, it, model } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: PerplexityPlugin.id, effect: PerplexityPlugin.effect(host) })
+})
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
 
 describe("PerplexityPlugin", () => {
   it.effect("creates a Perplexity SDK for the exact @ai-sdk/perplexity package", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, PerplexityPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("perplexity", "sonar"), package: "@ai-sdk/perplexity", options: { name: "perplexity" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("perplexity"), ModelV2.ID.make("sonar")),
+            api: { id: ModelV2.ID.make("sonar"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/perplexity",
+          options: { name: "perplexity" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -22,11 +54,14 @@ describe("PerplexityPlugin", () => {
   it.effect("ignores packages that are not the bundled Perplexity package", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, PerplexityPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("perplexity", "sonar"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("perplexity"), ModelV2.ID.make("sonar")),
+            api: { id: ModelV2.ID.make("sonar"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/perplexity-compatible",
           options: { name: "perplexity" },
         },
@@ -39,50 +74,40 @@ describe("PerplexityPlugin", () => {
   it.effect("uses the Perplexity provider ID as the SDK name for the bundled provider", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      const providers: string[] = []
-      yield* addPlugin(plugin, PerplexityPlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("perplexity-sdk-inspector"),
-        effect: Effect.succeed({
-          "aisdk.sdk": (evt) =>
-            Effect.sync(() => {
-              providers.push(evt.sdk.languageModel("sonar").provider)
-            }),
-        }),
-      })
-      yield* plugin.trigger(
+      yield* addPlugin()
+      const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("perplexity", "sonar"), package: "@ai-sdk/perplexity", options: { name: "perplexity" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("perplexity"), ModelV2.ID.make("sonar")),
+            api: { id: ModelV2.ID.make("sonar"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/perplexity",
+          options: { name: "perplexity" },
+        },
         {},
       )
-      expect(providers).toEqual(["perplexity"])
+      expect(result.sdk.languageModel("sonar").provider).toBe("perplexity")
     }),
   )
 
   it.effect("creates bundled Perplexity SDKs for custom provider IDs", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      const providers: string[] = []
-      yield* addPlugin(plugin, PerplexityPlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("custom-perplexity-sdk-inspector"),
-        effect: Effect.succeed({
-          "aisdk.sdk": (evt) =>
-            Effect.sync(() => {
-              providers.push(evt.sdk.languageModel("sonar").provider)
-            }),
-        }),
-      })
-      yield* plugin.trigger(
+      yield* addPlugin()
+      const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-perplexity", "sonar"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-perplexity"), ModelV2.ID.make("sonar")),
+            api: { id: ModelV2.ID.make("sonar"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/perplexity",
           options: { name: "custom-perplexity" },
         },
         {},
       )
-      expect(providers).toEqual(["perplexity"])
+      expect(result.sdk.languageModel("sonar").provider).toBe("perplexity")
     }),
   )
 
@@ -90,11 +115,14 @@ describe("PerplexityPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, PerplexityPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("perplexity", "alias", { api: { id: ModelV2.ID.make("sonar") } }),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("perplexity"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("sonar"), type: "aisdk", package: "test-provider" },
+          }),
           sdk: fakeSelectorSdk(calls),
           options: {},
         },

packages/core/test/plugin/provider-sap-ai-core.test.ts

@@ -1,16 +1,54 @@
 import { describe, expect } from "bun:test"
 import { Effect } from "effect"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { Npm } from "@opencode-ai/core/npm"
 import { SapAICorePlugin } from "@opencode-ai/core/plugin/provider/sap-ai-core"
-import { fixtureProvider, it, model, npmLayer, withEnv } from "./provider-helper"
-import { host } from "./host"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
 
-const pluginWithNpm = {
-  id: SapAICorePlugin.id,
-  effect: Effect.gen(function* () {
-    yield* SapAICorePlugin.effect(host({ npm: yield* Npm.Service }))
-  }).pipe(Effect.provide(npmLayer)),
+const fixtureProvider = new URL("./fixtures/provider-factory.ts", import.meta.url).href
+const it = testEffect(PluginTestLayer)
+const npm = Npm.Service.of({
+  add: () => Effect.succeed({ directory: "", entrypoint: undefined }),
+  install: () => Effect.void,
+  which: () => Effect.succeed(undefined),
+})
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: SapAICorePlugin.id, effect: SapAICorePlugin.effect({ ...host, npm }) })
+})
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, effect: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      for (const [key, value] of Object.entries(vars)) {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      }
+      return previous
+    }),
+    effect,
+    (previous) =>
+      Effect.sync(() => {
+        for (const [key, value] of Object.entries(previous)) {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        }
+      }),
+  )
+}
+
+function model(providerID: string) {
+  return new ModelV2.Info({
+    ...ModelV2.Info.empty(ProviderV2.ID.make(providerID), ModelV2.ID.make("sap-model")),
+    api: { id: ModelV2.ID.make("sap-model"), type: "aisdk", package: fixtureProvider },
+  })
 }
 
 describe("SapAICorePlugin", () => {
@@ -20,11 +58,11 @@ describe("SapAICorePlugin", () => {
       () =>
         Effect.gen(function* () {
           const plugin = yield* PluginV2.Service
-          yield* plugin.add(pluginWithNpm)
+          yield* addPlugin()
           const sdk = yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("sap-ai-core", "sap-model"),
+              model: model("sap-ai-core"),
               package: fixtureProvider,
               options: { name: "sap-ai-core", serviceKey: "service-key" },
             },
@@ -46,11 +84,11 @@ describe("SapAICorePlugin", () => {
       () =>
         Effect.gen(function* () {
           const plugin = yield* PluginV2.Service
-          yield* plugin.add(pluginWithNpm)
+          yield* addPlugin()
           const sdk = yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("sap-ai-core", "sap-model"),
+              model: model("sap-ai-core"),
               package: fixtureProvider,
               options: { name: "sap-ai-core", serviceKey: "option-service-key" },
             },
@@ -68,10 +106,10 @@ describe("SapAICorePlugin", () => {
       () =>
         Effect.gen(function* () {
           const plugin = yield* PluginV2.Service
-          yield* plugin.add(pluginWithNpm)
+          yield* addPlugin()
           const sdk = yield* plugin.trigger(
             "aisdk.sdk",
-            { model: model("sap-ai-core", "sap-model"), package: fixtureProvider, options: { name: "sap-ai-core" } },
+            { model: model("sap-ai-core"), package: fixtureProvider, options: { name: "sap-ai-core" } },
             {},
           )
           expect(process.env.AICORE_SERVICE_KEY).toBeUndefined()
@@ -83,17 +121,13 @@ describe("SapAICorePlugin", () => {
   it.effect("uses the callable SDK for language selection", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* plugin.add(pluginWithNpm)
+      yield* addPlugin()
       const sdk = Object.assign((modelID: string) => ({ modelID, provider: "callable" }), {
         languageModel() {
           throw new Error("SAP AI Core should call the SDK directly")
         },
       })
-      const language = yield* plugin.trigger(
-        "aisdk.language",
-        { model: model("sap-ai-core", "sap-model"), sdk, options: {} },
-        {},
-      )
+      const language = yield* plugin.trigger("aisdk.language", { model: model("sap-ai-core"), sdk, options: {} }, {})
       expect(language.language as unknown).toEqual({ modelID: "sap-model", provider: "callable" })
     }),
   )
@@ -104,11 +138,11 @@ describe("SapAICorePlugin", () => {
       () =>
         Effect.gen(function* () {
           const plugin = yield* PluginV2.Service
-          yield* plugin.add(pluginWithNpm)
+          yield* addPlugin()
           const sdk = yield* plugin.trigger(
             "aisdk.sdk",
             {
-              model: model("openai", "sap-model"),
+              model: model("openai"),
               package: fixtureProvider,
               options: { name: "openai", serviceKey: "service-key" },
             },
@@ -117,7 +151,7 @@ describe("SapAICorePlugin", () => {
           const language = yield* plugin.trigger(
             "aisdk.language",
             {
-              model: model("openai", "sap-model"),
+              model: model("openai"),
               sdk: () => {
                 throw new Error("SAP AI Core should ignore other providers")
               },

packages/core/test/plugin/provider-snowflake-cortex.test.ts

@@ -1,18 +1,48 @@
 import { describe, expect, it as bun_it } from "bun:test"
 import { Effect } from "effect"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { SnowflakeCortexPlugin, cortexFetch } from "@opencode-ai/core/plugin/provider/snowflake-cortex"
 import { ProviderPlugins } from "@opencode-ai/core/plugin/provider"
-import { addPlugin, expectPluginRegistered, it, model, withEnv } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: SnowflakeCortexPlugin.id, effect: SnowflakeCortexPlugin.effect(host) })
+})
+
+function withEnv<A, E, R>(vars: Record<string, string | undefined>, effect: () => Effect.Effect<A, E, R>) {
+  return Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const previous = Object.fromEntries(Object.keys(vars).map((key) => [key, process.env[key]]))
+      Object.entries(vars).forEach(([key, value]) => {
+        if (value === undefined) delete process.env[key]
+        else process.env[key] = value
+      })
+      return previous
+    }),
+    effect,
+    (previous) =>
+      Effect.sync(() => {
+        Object.entries(previous).forEach(([key, value]) => {
+          if (value === undefined) delete process.env[key]
+          else process.env[key] = value
+        })
+      }),
+  )
+}
 
 describe("SnowflakeCortexPlugin", () => {
   it.effect("is registered in ProviderPlugins before OpenAICompatiblePlugin", () =>
     Effect.sync(() => {
-      expectPluginRegistered(
-        ProviderPlugins.map((item) => item.id),
-        "snowflake-cortex",
-      )
-      const ids = ProviderPlugins.map((p) => p.id as string)
+      expect(ProviderPlugins.map((item) => item.id)).toContain(PluginV2.ID.make("snowflake-cortex"))
+      const ids = ProviderPlugins.map((p) => p.id)
       expect(ids.indexOf("snowflake-cortex")).toBeLessThan(ids.indexOf("openai-compatible"))
     }),
   )
@@ -20,10 +50,17 @@ describe("SnowflakeCortexPlugin", () => {
   it.effect("ignores non-snowflake-cortex providers", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, SnowflakeCortexPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("openai", "gpt-4"), package: "@ai-sdk/openai", options: { name: "openai" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("openai"), ModelV2.ID.make("gpt-4")),
+            api: { id: ModelV2.ID.make("gpt-4"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/openai",
+          options: { name: "openai" },
+        },
         {},
       )
       expect(result.sdk).toBeUndefined()
@@ -34,11 +71,14 @@ describe("SnowflakeCortexPlugin", () => {
     withEnv({ SNOWFLAKE_CORTEX_PAT: "test-pat" }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, SnowflakeCortexPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("snowflake-cortex", "claude-sonnet-4-6"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("snowflake-cortex"), ModelV2.ID.make("claude-sonnet-4-6")),
+              api: { id: ModelV2.ID.make("claude-sonnet-4-6"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/openai-compatible",
             options: { name: "snowflake-cortex", baseURL: "https://test.snowflakecomputing.com/api/v2/cortex/v1" },
           },
@@ -53,11 +93,14 @@ describe("SnowflakeCortexPlugin", () => {
     withEnv({ SNOWFLAKE_CORTEX_PAT: undefined }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, SnowflakeCortexPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("snowflake-cortex", "claude-sonnet-4-6"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("snowflake-cortex"), ModelV2.ID.make("claude-sonnet-4-6")),
+              api: { id: ModelV2.ID.make("claude-sonnet-4-6"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/openai-compatible",
             options: {
               name: "snowflake-cortex",
@@ -76,11 +119,14 @@ describe("SnowflakeCortexPlugin", () => {
     withEnv({ SNOWFLAKE_CORTEX_TOKEN: "oauth-token", SNOWFLAKE_CORTEX_PAT: undefined }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, SnowflakeCortexPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("snowflake-cortex", "claude-sonnet-4-6"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("snowflake-cortex"), ModelV2.ID.make("claude-sonnet-4-6")),
+              api: { id: ModelV2.ID.make("claude-sonnet-4-6"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/openai-compatible",
             options: { name: "snowflake-cortex", baseURL: "https://test.snowflakecomputing.com/api/v2/cortex/v1" },
           },
@@ -95,11 +141,14 @@ describe("SnowflakeCortexPlugin", () => {
     withEnv({ SNOWFLAKE_CORTEX_TOKEN: undefined, SNOWFLAKE_CORTEX_PAT: undefined }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        yield* addPlugin(plugin, SnowflakeCortexPlugin)
+        yield* addPlugin()
         const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("snowflake-cortex", "claude-sonnet-4-6"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("snowflake-cortex"), ModelV2.ID.make("claude-sonnet-4-6")),
+              api: { id: ModelV2.ID.make("claude-sonnet-4-6"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/openai-compatible",
             options: {
               name: "snowflake-cortex",
@@ -118,27 +167,20 @@ describe("SnowflakeCortexPlugin", () => {
     withEnv({ SNOWFLAKE_CORTEX_PAT: "test-pat" }, () =>
       Effect.gen(function* () {
         const plugin = yield* PluginV2.Service
-        const captured: Record<string, unknown>[] = []
-        yield* addPlugin(plugin, SnowflakeCortexPlugin)
-        yield* plugin.add({
-          id: PluginV2.ID.make("inspector"),
-          effect: Effect.succeed({
-            "aisdk.sdk": (evt) =>
-              Effect.sync(() => {
-                captured.push({ ...evt.options })
-              }),
-          }),
-        })
-        yield* plugin.trigger(
+        yield* addPlugin()
+        const result = yield* plugin.trigger(
           "aisdk.sdk",
           {
-            model: model("snowflake-cortex", "claude-sonnet-4-6"),
+            model: new ModelV2.Info({
+              ...ModelV2.Info.empty(ProviderV2.ID.make("snowflake-cortex"), ModelV2.ID.make("claude-sonnet-4-6")),
+              api: { id: ModelV2.ID.make("claude-sonnet-4-6"), type: "aisdk", package: "test-provider" },
+            }),
             package: "@ai-sdk/openai-compatible",
             options: { name: "snowflake-cortex", baseURL: "https://test.snowflakecomputing.com/api/v2/cortex/v1" },
           },
           {},
         )
-        expect(captured[0]?.includeUsage).toBe(true)
+        expect(result.options.includeUsage).toBe(true)
       }),
     ),
   )

packages/core/test/plugin/provider-togetherai.test.ts

@@ -1,17 +1,50 @@
 import { describe, expect } from "bun:test"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { Effect } from "effect"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { TogetherAIPlugin } from "@opencode-ai/core/plugin/provider/togetherai"
-import { addPlugin, fakeSelectorSdk, it, model } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: TogetherAIPlugin.id, effect: TogetherAIPlugin.effect(host) })
+})
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
 
 describe("TogetherAIPlugin", () => {
   it.effect("creates a TogetherAI SDK for @ai-sdk/togetherai", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, TogetherAIPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("togetherai", "model"), package: "@ai-sdk/togetherai", options: { name: "togetherai" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("togetherai"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/togetherai",
+          options: { name: "togetherai" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -21,12 +54,15 @@ describe("TogetherAIPlugin", () => {
   it.effect("matches the old bundled provider package exactly", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, TogetherAIPlugin)
+      yield* addPlugin()
 
       const ignored = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("togetherai", "model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("togetherai"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
           package: "file:///tmp/@ai-sdk/togetherai-provider.js",
           options: { name: "togetherai" },
         },
@@ -36,7 +72,14 @@ describe("TogetherAIPlugin", () => {
 
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("togetherai", "model"), package: "@ai-sdk/togetherai", options: { name: "togetherai" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("togetherai"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/togetherai",
+          options: { name: "togetherai" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -46,29 +89,22 @@ describe("TogetherAIPlugin", () => {
   it.effect("creates bundled TogetherAI SDKs for custom provider IDs", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      const observed: string[] = []
-      yield* addPlugin(plugin, TogetherAIPlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("inspector"),
-        effect: Effect.succeed({
-          "aisdk.sdk": (evt) =>
-            Effect.sync(() => {
-              observed.push(evt.sdk.languageModel("model").provider)
-            }),
-        }),
-      })
+      yield* addPlugin()
 
-      yield* plugin.trigger(
+      const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-togetherai", "model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-togetherai"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
           package: "@ai-sdk/togetherai",
           options: { name: "custom-togetherai" },
         },
         {},
       )
 
-      expect(observed).toEqual(["togetherai.chat"])
+      expect(result.sdk.languageModel("model").provider).toBe("togetherai.chat")
     }),
   )
 
@@ -76,12 +112,22 @@ describe("TogetherAIPlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, TogetherAIPlugin)
+      yield* addPlugin()
 
       const result = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: model("togetherai", "meta-llama/Llama-3.3-70B-Instruct-Turbo"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(
+              ProviderV2.ID.make("togetherai"),
+              ModelV2.ID.make("meta-llama/Llama-3.3-70B-Instruct-Turbo"),
+            ),
+            api: {
+              id: ModelV2.ID.make("meta-llama/Llama-3.3-70B-Instruct-Turbo"),
+              type: "aisdk",
+              package: "test-provider",
+            },
+          }),
           sdk: { languageModel: fakeSelectorSdk(calls).languageModel },
           options: {},
         },

packages/core/test/plugin/provider-venice.test.ts

@@ -1,17 +1,50 @@
 import { describe, expect } from "bun:test"
+import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { Effect } from "effect"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { VenicePlugin } from "@opencode-ai/core/plugin/provider/venice"
-import { addPlugin, fakeSelectorSdk, it, model } from "./provider-helper"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: VenicePlugin.id, effect: VenicePlugin.effect(host) })
+})
+
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
 
 describe("VenicePlugin", () => {
   it.effect("creates a Venice SDK for venice-ai-sdk-provider", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, VenicePlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("venice", "model"), package: "venice-ai-sdk-provider", options: { name: "venice" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("venice"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "venice-ai-sdk-provider",
+          options: { name: "venice" },
+        },
         {},
       )
       expect(result.sdk).toBeDefined()
@@ -21,39 +54,35 @@ describe("VenicePlugin", () => {
   it.effect("uses the model provider ID as the bundled Venice SDK name", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      const observed: string[] = []
-      yield* addPlugin(plugin, VenicePlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("inspector"),
-        effect: Effect.succeed({
-          "aisdk.sdk": (evt) =>
-            Effect.sync(() => {
-              observed.push(evt.sdk.languageModel("model").provider)
-            }),
-        }),
-      })
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("custom-venice", "model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-venice"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
           package: "venice-ai-sdk-provider",
           options: { name: "custom-venice", apiKey: "test" },
         },
         {},
       )
       expect(result.sdk).toBeDefined()
-      expect(observed).toEqual(["custom-venice.chat"])
+      expect(result.sdk.languageModel("model").provider).toBe("custom-venice.chat")
     }),
   )
 
   it.effect("only handles the bundled venice-ai-sdk-provider package", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, VenicePlugin)
+      yield* addPlugin()
       const similar = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: model("venice", "model"),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("venice"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
           package: "file:///tmp/venice-ai-sdk-provider.js",
           options: { name: "venice" },
         },
@@ -61,7 +90,14 @@ describe("VenicePlugin", () => {
       )
       const other = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("venice", "model"), package: "@ai-sdk/openai-compatible", options: { name: "venice" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("venice"), ModelV2.ID.make("model")),
+            api: { id: ModelV2.ID.make("model"), type: "aisdk", package: "test-provider" },
+          }),
+          package: "@ai-sdk/openai-compatible",
+          options: { name: "venice" },
+        },
         {},
       )
       expect(similar.sdk).toBeUndefined()
@@ -73,10 +109,17 @@ describe("VenicePlugin", () => {
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
-      yield* addPlugin(plugin, VenicePlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
-        { model: model("venice", "alias"), sdk: fakeSelectorSdk(calls), options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("venice"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("alias"), type: "aisdk", package: "test-provider" },
+          }),
+          sdk: fakeSelectorSdk(calls),
+          options: {},
+        },
         {},
       )
       expect(calls).toEqual([])

packages/core/test/plugin/provider-vercel.test.ts

@@ -1,28 +1,34 @@
 import { describe, expect } from "bun:test"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
+import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { VercelPlugin } from "@opencode-ai/core/plugin/provider/vercel"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, it, model, provider, required } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: VercelPlugin.id, effect: VercelPlugin.effect(host) })
+})
 
 describe("VercelPlugin", () => {
   it.effect("applies legacy lower-case referer headers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, VercelPlugin)
       yield* catalog.transform((catalog) => {
-        const item = provider("vercel", {
-          api: { type: "aisdk", package: "@ai-sdk/vercel" },
-          request: { headers: { Existing: "1" }, body: {} },
-        })
-        catalog.provider.update(item.id, (draft) => {
-          draft.api = item.api
-          draft.request = item.request
+        catalog.provider.update(ProviderV2.ID.make("vercel"), (provider) => {
+          provider.api = { type: "aisdk", package: "@ai-sdk/vercel" }
+          provider.request.headers.Existing = "1"
         })
       })
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("vercel"))).request.headers).toEqual({
+      yield* addPlugin()
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("vercel")))?.request.headers).toEqual({
         Existing: "1",
         "http-referer": "https://opencode.ai/",
         "x-title": "opencode",
@@ -32,31 +38,34 @@ describe("VercelPlugin", () => {
 
   it.effect("does not add legacy upper-case referer headers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, VercelPlugin)
-      yield* catalog.transform((catalog) => {
-        const item = provider("vercel", { api: { type: "aisdk", package: "@ai-sdk/vercel" } })
-        catalog.provider.update(item.id, (draft) => {
-          draft.api = item.api
-        })
-      })
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("vercel"))).request.headers).not.toHaveProperty(
+      yield* catalog.transform((catalog) =>
+        catalog.provider.update(ProviderV2.ID.make("vercel"), (provider) => {
+          provider.api = { type: "aisdk", package: "@ai-sdk/vercel" }
+        }),
+      )
+      yield* addPlugin()
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("vercel")))?.request.headers).not.toHaveProperty(
         "HTTP-Referer",
       )
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("vercel"))).request.headers).not.toHaveProperty(
-        "X-Title",
-      )
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("vercel")))?.request.headers).not.toHaveProperty("X-Title")
     }),
   )
 
   it.effect("creates @ai-sdk/vercel SDKs for custom provider IDs", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, VercelPlugin)
+      yield* addPlugin()
       const event = yield* plugin.trigger(
         "aisdk.sdk",
-        { model: model("custom-vercel", "v0-1.0-md"), package: "@ai-sdk/vercel", options: { name: "custom-vercel" } },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-vercel"), ModelV2.ID.make("v0-1.0-md")),
+            api: { id: ModelV2.ID.make("v0-1.0-md"), type: "aisdk", package: "@ai-sdk/vercel" },
+          }),
+          package: "@ai-sdk/vercel",
+          options: { name: "custom-vercel" },
+        },
         {},
       )
       expect(event.sdk).toBeDefined()
@@ -66,11 +75,10 @@ describe("VercelPlugin", () => {
 
   it.effect("ignores non-Vercel providers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, VercelPlugin)
-      yield* catalog.transform((catalog) => catalog.provider.update(provider("gateway").id, () => {}))
-      expect(required(yield* catalog.provider.get(ProviderV2.ID.make("gateway"))).request.headers).toEqual({})
+      yield* catalog.transform((catalog) => catalog.provider.update(ProviderV2.ID.make("gateway"), () => {}))
+      yield* addPlugin()
+      expect((yield* catalog.provider.get(ProviderV2.ID.make("gateway")))?.request.headers).toEqual({})
     }),
   )
 })

packages/core/test/plugin/provider-xai.test.ts

@@ -1,37 +1,66 @@
+import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { describe, expect } from "bun:test"
-import { Effect, Layer } from "effect"
-import { EventV2 } from "@opencode-ai/core/event"
+import { Effect } from "effect"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { XAIPlugin } from "@opencode-ai/core/plugin/provider/xai"
 import { ProviderV2 } from "@opencode-ai/core/provider"
 import { testEffect } from "../lib/effect"
-import { addPlugin, fakeSelectorSdk } from "./provider-helper"
+import { PluginTestLayer } from "./fixture"
 
-const it = testEffect(PluginV2.locationLayer.pipe(Layer.provide(EventV2.defaultLayer)))
+const it = testEffect(PluginTestLayer)
 
-const model = new ModelV2.Info({
-  ...ModelV2.Info.empty(ProviderV2.ID.make("xai"), ModelV2.ID.make("grok-4")),
-  api: {
-    id: ModelV2.ID.make("grok-4"),
-    type: "aisdk",
-    package: "@ai-sdk/xai",
-  },
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: XAIPlugin.id, effect: XAIPlugin.effect(host) })
 })
 
+function fakeSelectorSdk(calls: string[]) {
+  const make = (method: string) => (id: string) => {
+    calls.push(`${method}:${id}`)
+    return { modelId: id, provider: method, specificationVersion: "v3" } as unknown as LanguageModelV3
+  }
+  return {
+    responses: make("responses"),
+    messages: make("messages"),
+    chat: make("chat"),
+    languageModel: make("languageModel"),
+  }
+}
+
 describe("XAIPlugin", () => {
   it.effect("creates an xAI SDK only for @ai-sdk/xai", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      yield* addPlugin(plugin, XAIPlugin)
+      yield* addPlugin()
 
       const ignored = yield* plugin.trigger(
         "aisdk.sdk",
-        { model, package: "@ai-sdk/openai-compatible", options: {} },
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("xai"), ModelV2.ID.make("grok-4")),
+            api: { id: ModelV2.ID.make("grok-4"), type: "aisdk", package: "@ai-sdk/xai" },
+          }),
+          package: "@ai-sdk/openai-compatible",
+          options: {},
+        },
         {},
       )
 
-      const result = yield* plugin.trigger("aisdk.sdk", { model, package: "@ai-sdk/xai", options: {} }, {})
+      const result = yield* plugin.trigger(
+        "aisdk.sdk",
+        {
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("xai"), ModelV2.ID.make("grok-4")),
+            api: { id: ModelV2.ID.make("grok-4"), type: "aisdk", package: "@ai-sdk/xai" },
+          }),
+          package: "@ai-sdk/xai",
+          options: {},
+        },
+        {},
+      )
 
       expect(ignored.sdk).toBeUndefined()
       expect(typeof result.sdk?.responses).toBe("function")
@@ -41,32 +70,22 @@ describe("XAIPlugin", () => {
   it.effect("creates xAI SDKs for custom provider IDs", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service
-      const providers: string[] = []
+      yield* addPlugin()
 
-      yield* addPlugin(plugin, XAIPlugin)
-      yield* plugin.add({
-        id: PluginV2.ID.make("xai-sdk-name-observer"),
-        effect: Effect.gen(function* () {
-          return {
-            "aisdk.sdk": Effect.fn(function* (evt) {
-              if (!evt.sdk) return
-              providers.push(evt.sdk.responses("grok-4").provider)
-            }),
-          }
-        }),
-      })
-
-      yield* plugin.trigger(
+      const result = yield* plugin.trigger(
         "aisdk.sdk",
         {
-          model: new ModelV2.Info({ ...model, providerID: ProviderV2.ID.make("custom-xai") }),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("custom-xai"), ModelV2.ID.make("grok-4")),
+            api: { id: ModelV2.ID.make("grok-4"), type: "aisdk", package: "@ai-sdk/xai" },
+          }),
           package: "@ai-sdk/xai",
           options: {},
         },
         {},
       )
 
-      expect(providers).toEqual(["xai.responses"])
+      expect(result.sdk.responses("grok-4").provider).toBe("xai.responses")
     }),
   )
 
@@ -75,11 +94,14 @@ describe("XAIPlugin", () => {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
 
-      yield* addPlugin(plugin, XAIPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: new ModelV2.Info({ ...model, id: ModelV2.ID.make("alias") }),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.make("xai"), ModelV2.ID.make("alias")),
+            api: { id: ModelV2.ID.make("grok-4"), type: "aisdk", package: "@ai-sdk/xai" },
+          }),
           sdk: fakeSelectorSdk(calls),
           options: {},
         },
@@ -96,11 +118,14 @@ describe("XAIPlugin", () => {
       const plugin = yield* PluginV2.Service
       const calls: string[] = []
 
-      yield* addPlugin(plugin, XAIPlugin)
+      yield* addPlugin()
       const result = yield* plugin.trigger(
         "aisdk.language",
         {
-          model: new ModelV2.Info({ ...model, providerID: ProviderV2.ID.openai }),
+          model: new ModelV2.Info({
+            ...ModelV2.Info.empty(ProviderV2.ID.openai, ModelV2.ID.make("grok-4")),
+            api: { id: ModelV2.ID.make("grok-4"), type: "aisdk", package: "@ai-sdk/xai" },
+          }),
           sdk: fakeSelectorSdk(calls),
           options: {},
         },

packages/core/test/plugin/provider-zenmux.test.ts

@@ -2,34 +2,44 @@ import { describe, expect } from "bun:test"
 import { Effect } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { PluginV2 } from "@opencode-ai/core/plugin"
+import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { ProviderPlugins } from "@opencode-ai/core/plugin/provider"
 import { ZenmuxPlugin } from "@opencode-ai/core/plugin/provider/zenmux"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { addPlugin, expectPluginRegistered, it, provider, required } from "./provider-helper"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+
+const addPlugin = Effect.fn(function* () {
+  const plugin = yield* PluginV2.Service
+  const host = yield* PluginHost.make()
+  yield* plugin.add({ id: ZenmuxPlugin.id, effect: ZenmuxPlugin.effect(host) })
+})
+
+function required<T>(value: T | undefined): T {
+  if (value === undefined) throw new Error("Expected value")
+  return value
+}
 
 describe("ZenmuxPlugin", () => {
   it.effect("is registered so legacy referer headers can be applied", () =>
-    Effect.sync(() =>
-      expectPluginRegistered(
-        ProviderPlugins.map((item) => item.id),
-        "zenmux",
-      ),
-    ),
+    Effect.sync(() => expect(ProviderPlugins.map((item) => item.id)).toContain(PluginV2.ID.make("zenmux"))),
   )
 
   it.effect("applies the exact legacy Zenmux headers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, ZenmuxPlugin)
       yield* catalog.transform((catalog) => {
-        const item = provider("zenmux", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://zenmux.ai/api/v1" },
-        })
-        catalog.provider.update(item.id, (draft) => {
-          draft.api = item.api
+        catalog.provider.update(ProviderV2.ID.make("zenmux"), (provider) => {
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://zenmux.ai/api/v1",
+          }
         })
       })
+      yield* addPlugin()
       const result = required(yield* catalog.provider.get(ProviderV2.ID.make("zenmux")))
       expect(result.request.headers).toEqual({ "HTTP-Referer": "https://opencode.ai/", "X-Title": "opencode" })
       expect(Object.keys(result.request.headers).sort()).toEqual(["HTTP-Referer", "X-Title"])
@@ -38,19 +48,18 @@ describe("ZenmuxPlugin", () => {
 
   it.effect("merges legacy Zenmux headers with existing headers", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, ZenmuxPlugin)
       yield* catalog.transform((catalog) => {
-        const item = provider("zenmux", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://zenmux.ai/api/v1" },
-          request: { headers: { Existing: "value" }, body: {} },
-        })
-        catalog.provider.update(item.id, (draft) => {
-          draft.api = item.api
-          draft.request = item.request
+        catalog.provider.update(ProviderV2.ID.make("zenmux"), (provider) => {
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://zenmux.ai/api/v1",
+          }
+          provider.request.headers.Existing = "value"
         })
       })
+      yield* addPlugin()
 
       expect(required(yield* catalog.provider.get(ProviderV2.ID.make("zenmux"))).request.headers).toEqual({
         Existing: "value",
@@ -62,22 +71,18 @@ describe("ZenmuxPlugin", () => {
 
   it.effect("lets configured Zenmux legacy headers override defaults", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, ZenmuxPlugin)
       yield* catalog.transform((catalog) => {
-        const item = provider("zenmux", {
-          api: { type: "aisdk", package: "@ai-sdk/openai-compatible", url: "https://zenmux.ai/api/v1" },
-          request: {
-            headers: { "HTTP-Referer": "https://example.com/", "X-Title": "custom-title" },
-            body: {},
-          },
-        })
-        catalog.provider.update(item.id, (draft) => {
-          draft.api = item.api
-          draft.request = item.request
+        catalog.provider.update(ProviderV2.ID.make("zenmux"), (provider) => {
+          provider.api = {
+            type: "aisdk",
+            package: "@ai-sdk/openai-compatible",
+            url: "https://zenmux.ai/api/v1",
+          }
+          provider.request.headers = { "HTTP-Referer": "https://example.com/", "X-Title": "custom-title" }
         })
       })
+      yield* addPlugin()
 
       expect(required(yield* catalog.provider.get(ProviderV2.ID.make("zenmux"))).request.headers).toEqual({
         "HTTP-Referer": "https://example.com/",
@@ -88,20 +93,13 @@ describe("ZenmuxPlugin", () => {
 
   it.effect("guards legacy Zenmux headers to the exact zenmux provider id", () =>
     Effect.gen(function* () {
-      const plugin = yield* PluginV2.Service
       const catalog = yield* Catalog.Service
-      yield* addPlugin(plugin, ZenmuxPlugin)
       yield* catalog.transform((catalog) => {
-        const item = provider("openrouter", {
-          request: {
-            headers: { "HTTP-Referer": "https://example.com/", "X-Title": "custom-title" },
-            body: {},
-          },
-        })
-        catalog.provider.update(item.id, (draft) => {
-          draft.request = item.request
+        catalog.provider.update(ProviderV2.ID.openrouter, (provider) => {
+          provider.request.headers = { "HTTP-Referer": "https://example.com/", "X-Title": "custom-title" }
         })
       })
+      yield* addPlugin()
 
       expect(required(yield* catalog.provider.get(ProviderV2.ID.openrouter)).request.headers).toEqual({
         "HTTP-Referer": "https://example.com/",

packages/core/test/preload.ts

@@ -0,0 +1 @@
+process.env.OPENCODE_DB = ":memory:"

packages/core/test/project-copy.test.ts

@@ -16,17 +16,16 @@ import { ProjectDirectories } from "@opencode-ai/core/project/directories"
 import { tmpdir } from "./fixture/tmpdir"
 import { testEffect } from "./lib/effect"
 
-const databaseLayer = Database.layerFromPath(":memory:")
-const eventLayer = EventV2.layer.pipe(Layer.provide(databaseLayer))
-const directoriesLayer = ProjectDirectories.layer.pipe(Layer.provide(databaseLayer))
 const copyLayer = ProjectCopy.layer.pipe(
-  Layer.provide(databaseLayer),
-  Layer.provide(directoriesLayer),
-  Layer.provide(eventLayer),
+  Layer.provide(Database.defaultLayer),
+  Layer.provide(ProjectDirectories.defaultLayer),
+  Layer.provide(EventV2.defaultLayer),
   Layer.provide(FSUtil.defaultLayer),
   Layer.provide(Git.defaultLayer),
 )
-const it = testEffect(Layer.mergeAll(copyLayer, databaseLayer, eventLayer, directoriesLayer))
+const it = testEffect(
+  Layer.mergeAll(copyLayer, Database.defaultLayer, EventV2.defaultLayer, ProjectDirectories.defaultLayer),
+)
 
 function abs(input: string) {
   return AbsolutePath.make(input)

packages/core/test/project-directories.test.ts

@@ -8,10 +8,7 @@ import { ProjectTable } from "@opencode-ai/core/project/sql"
 import { AbsolutePath } from "@opencode-ai/core/schema"
 import { testEffect } from "./lib/effect"
 
-const database = Database.layerFromPath(":memory:")
-const events = EventV2.layer.pipe(Layer.provide(database))
-const directories = ProjectDirectories.layer.pipe(Layer.provide(database), Layer.provide(events))
-const it = testEffect(Layer.mergeAll(database, events, directories))
+const it = testEffect(Layer.mergeAll(Database.defaultLayer, EventV2.defaultLayer, ProjectDirectories.defaultLayer))
 
 const projectID = Project.ID.make("project-directories")
 const directory = AbsolutePath.make("/tmp/project-directories")

packages/core/test/project.test.ts

@@ -13,20 +13,7 @@ import { ProjectDirectories } from "@opencode-ai/core/project/directories"
 import { tmpdir } from "./fixture/tmpdir"
 import { testEffect } from "./lib/effect"
 
-const databaseLayer = Database.layerFromPath(":memory:")
-const directoriesLayer = ProjectDirectories.layer.pipe(Layer.provide(databaseLayer))
-const it = testEffect(
-  Layer.mergeAll(
-    ProjectV2.layer.pipe(
-      Layer.provide(FSUtil.defaultLayer),
-      Layer.provide(Git.defaultLayer),
-      Layer.provide(directoriesLayer),
-      Layer.provide(databaseLayer),
-    ),
-    databaseLayer,
-    directoriesLayer,
-  ),
-)
+const it = testEffect(Layer.mergeAll(ProjectV2.defaultLayer, Database.defaultLayer, ProjectDirectories.defaultLayer))
 
 function remoteID(remote: string) {
   return ProjectV2.ID.make(Hash.fast(`git-remote:${remote}`))

packages/core/test/public-opencode.test.ts

@@ -1,9 +1,6 @@
-import fs from "fs/promises"
-import path from "path"
 import { describe, expect } from "bun:test"
 import { Effect, Schema } from "effect"
 import { AbsolutePath, Location, Model, OpenCode, Session, Tool } from "@opencode-ai/core/public"
-import { tmpdir } from "./fixture/tmpdir"
 import { testEffect } from "./lib/effect"
 
 const it = testEffect(OpenCode.layer)
@@ -41,94 +38,24 @@ describe("public native OpenCode API", () => {
     }),
   )
 
-  it.effect("switches to an available model and variant", () =>
-    Effect.acquireRelease(
-      Effect.promise(() => tmpdir()),
-      (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
-    ).pipe(
-      Effect.flatMap((tmp) =>
-        Effect.gen(function* () {
-          yield* writeProvider(tmp.path)
-          const opencode = yield* OpenCode.Service
-          const sessionID = Session.ID.make("ses_public_switch_available")
-          const model = ref({ variant: "fast" })
-          yield* opencode.sessions.create({
-            id: sessionID,
-            location: Location.Ref.make({ directory: AbsolutePath.make(tmp.path) }),
-          })
+  it.effect("records model selection without resolving the Location catalog", () =>
+    Effect.gen(function* () {
+      const opencode = yield* OpenCode.Service
+      const sessionID = Session.ID.make("ses_public_switch_deferred")
+      const model = Schema.decodeUnknownSync(Model.Ref)({
+        id: "missing",
+        providerID: "missing",
+        variant: "unknown",
+      })
+      yield* opencode.sessions.create({
+        id: sessionID,
+        location: Location.Ref.make({ directory: AbsolutePath.make("/public-session-switch-model") }),
+      })
 
-          yield* opencode.sessions.switchModel({ sessionID, model })
+      yield* opencode.sessions.switchModel({ sessionID, model })
 
-          expect((yield* opencode.sessions.get(sessionID)).model).toEqual(model)
-        }),
-      ),
-    ),
-  )
-
-  it.effect("rejects missing and Location-disabled models without changing the Session", () =>
-    Effect.acquireRelease(
-      Effect.promise(() => Promise.all([tmpdir(), tmpdir()])),
-      (dirs) => Effect.promise(() => Promise.all(dirs.map((dir) => dir[Symbol.asyncDispose]())).then(() => undefined)),
-    ).pipe(
-      Effect.flatMap(([available, disabled]) =>
-        Effect.gen(function* () {
-          yield* writeProvider(available.path)
-          yield* writeProvider(disabled.path, true)
-          const opencode = yield* OpenCode.Service
-          const availableID = Session.ID.make("ses_public_switch_exact_available")
-          const disabledID = Session.ID.make("ses_public_switch_exact_disabled")
-          yield* opencode.sessions.create({
-            id: availableID,
-            location: Location.Ref.make({ directory: AbsolutePath.make(available.path) }),
-          })
-          yield* opencode.sessions.create({
-            id: disabledID,
-            location: Location.Ref.make({ directory: AbsolutePath.make(disabled.path) }),
-          })
-
-          yield* opencode.sessions.switchModel({ sessionID: availableID, model: ref({ variant: "default" }) })
-          const disabledError = yield* opencode.sessions
-            .switchModel({ sessionID: disabledID, model: ref() })
-            .pipe(Effect.flip)
-          const missingError = yield* opencode.sessions
-            .switchModel({ sessionID: disabledID, model: ref({ id: "missing" }) })
-            .pipe(Effect.flip)
-
-          expect(disabledError).toBeInstanceOf(Session.ModelUnavailableError)
-          expect(missingError).toBeInstanceOf(Session.ModelUnavailableError)
-          expect((yield* opencode.sessions.get(availableID)).model).toEqual(ref({ variant: "default" }))
-          expect((yield* opencode.sessions.get(disabledID)).model).toBeUndefined()
-        }),
-      ),
-    ),
-  )
-
-  it.effect("rejects an unavailable variant without changing the Session", () =>
-    Effect.acquireRelease(
-      Effect.promise(() => tmpdir()),
-      (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
-    ).pipe(
-      Effect.flatMap((tmp) =>
-        Effect.gen(function* () {
-          yield* writeProvider(tmp.path)
-          const opencode = yield* OpenCode.Service
-          const sessionID = Session.ID.make("ses_public_switch_variant")
-          const selected = ref({ variant: "fast" })
-          yield* opencode.sessions.create({
-            id: sessionID,
-            location: Location.Ref.make({ directory: AbsolutePath.make(tmp.path) }),
-          })
-          yield* opencode.sessions.switchModel({ sessionID, model: selected })
-
-          const error = yield* opencode.sessions
-            .switchModel({ sessionID, model: ref({ variant: "unknown" }) })
-            .pipe(Effect.flip)
-
-          expect(error).toBeInstanceOf(Session.VariantUnavailableError)
-          expect((yield* opencode.sessions.get(sessionID)).model).toEqual(selected)
-        }),
-      ),
-    ),
+      expect((yield* opencode.sessions.get(sessionID)).model).toEqual(model)
+    }),
   )
 
   it.effect("preserves the typed not-found error for a missing Session", () =>
@@ -147,31 +74,3 @@ describe("public native OpenCode API", () => {
     }),
   )
 })
-
-const ref = (input: { id?: string; variant?: string } = {}) =>
-  Schema.decodeUnknownSync(Model.Ref)({
-    id: input.id ?? "chat",
-    providerID: "public-test",
-    variant: input.variant,
-  })
-
-const writeProvider = (directory: string, disabled = false) =>
-  Effect.promise(() =>
-    fs.writeFile(
-      path.join(directory, "opencode.json"),
-      JSON.stringify({
-        providers: {
-          "public-test": {
-            name: "Public test",
-            api: { type: "native", settings: {} },
-            models: {
-              chat: {
-                disabled,
-                variants: [{ id: "fast" }],
-              },
-            },
-          },
-        },
-      }),
-    ),
-  )

packages/core/test/question.test.ts

@@ -6,10 +6,8 @@ import { QuestionV2 } from "@opencode-ai/core/question"
 import { SessionV2 } from "@opencode-ai/core/session"
 import { testEffect } from "./lib/effect"
 
-const database = Database.layerFromPath(":memory:")
-const events = EventV2.layer.pipe(Layer.provide(database))
-const questions = QuestionV2.layer.pipe(Layer.provide(events))
-const it = testEffect(Layer.mergeAll(database, events, questions))
+const questions = QuestionV2.layer.pipe(Layer.provide(EventV2.defaultLayer))
+const it = testEffect(Layer.mergeAll(Database.defaultLayer, EventV2.defaultLayer, questions))
 
 const sessionID = SessionV2.ID.make("ses_question_test")
 const question: QuestionV2.Info = {

packages/core/test/session-create.test.ts

@@ -11,7 +11,7 @@ import { ModelV2 } from "@opencode-ai/core/model"
 import { ProjectV2 } from "@opencode-ai/core/project"
 import { ProjectTable } from "@opencode-ai/core/project/sql"
 import { ProviderV2 } from "@opencode-ai/core/provider"
-import { AbsolutePath } from "@opencode-ai/core/schema"
+import { AbsolutePath, RelativePath } from "@opencode-ai/core/schema"
 import { SessionV2 } from "@opencode-ai/core/session"
 import { SessionV1 } from "@opencode-ai/core/v1/session"
 import { Prompt } from "@opencode-ai/core/session/prompt"
@@ -25,8 +25,6 @@ import { WorkspaceV2 } from "@opencode-ai/core/workspace"
 import { testEffect } from "./lib/effect"
 import { tmpdir } from "./fixture/tmpdir"
 
-const database = Database.layerFromPath(":memory:")
-const events = EventV2.layer.pipe(Layer.provide(database))
 const projects = Layer.succeed(
   ProjectV2.Service,
   ProjectV2.Service.of({
@@ -35,17 +33,23 @@ const projects = Layer.succeed(
     commit: () => Effect.void,
   }),
 )
-const projector = SessionProjector.layer.pipe(Layer.provide(events), Layer.provide(database))
-const store = SessionStore.layer.pipe(Layer.provide(database))
 const sessions = SessionV2.layer.pipe(
-  Layer.provide(events),
-  Layer.provide(database),
-  Layer.provide(store),
+  Layer.provide(EventV2.defaultLayer),
+  Layer.provide(Database.defaultLayer),
+  Layer.provide(SessionStore.defaultLayer),
   Layer.provide(projects),
   Layer.provide(SessionExecution.noopLayer),
 )
 const it = testEffect(
-  Layer.mergeAll(database, events, projects, projector, store, SessionExecution.noopLayer, sessions),
+  Layer.mergeAll(
+    Database.defaultLayer,
+    EventV2.defaultLayer,
+    projects,
+    SessionProjector.defaultLayer,
+    SessionStore.defaultLayer,
+    SessionExecution.noopLayer,
+    sessions,
+  ),
 )
 const location = Location.Ref.make({ directory: AbsolutePath.make("/project") })
 const id = SessionV2.ID.create()
@@ -336,7 +340,34 @@ describe("SessionV2.create", () => {
 
       expect(yield* unavailable(session.shell({ sessionID: created.id, command: "pwd" }))).toBe("shell")
       expect(yield* unavailable(session.skill({ sessionID: created.id, skill: "review" }))).toBe("skill")
-      expect(yield* unavailable(session.switchAgent({ sessionID: created.id, agent: "build" }))).toBe("switchAgent")
+    }),
+  )
+
+  it.effect("switches the selected agent through the durable Session event", () =>
+    Effect.gen(function* () {
+      const session = yield* SessionV2.Service
+      const created = yield* session.create({ location })
+
+      yield* session.switchAgent({ sessionID: created.id, agent: "plan" })
+
+      expect(yield* session.get(created.id)).toMatchObject({ agent: "plan" })
+      expect(
+        Array.from(yield* session.events({ sessionID: created.id }).pipe(Stream.take(1), Stream.runCollect)),
+      ).toMatchObject([{ type: "session.next.agent.switched", data: { agent: "plan" } }])
+    }),
+  )
+
+  it.effect("rejects an agent switch for a missing Session", () =>
+    Effect.gen(function* () {
+      const session = yield* SessionV2.Service
+      const missing = SessionV2.ID.make("ses_missing_agent_switch")
+
+      expect(
+        yield* session.switchAgent({ sessionID: missing, agent: "plan" }).pipe(
+          Effect.flip,
+          Effect.map((error) => error._tag),
+        ),
+      ).toBe("Session.NotFoundError")
     }),
   )
 
@@ -395,3 +426,54 @@ describe("SessionV2.create", () => {
     }),
   )
 })
+
+describe("SessionV2.list", () => {
+  it.effect("limits project sessions to the requested subpath", () =>
+    Effect.gen(function* () {
+      const session = yield* SessionV2.Service
+      const { db } = yield* Database.Service
+      const core = yield* session.create({ location })
+      const nested = yield* session.create({ location })
+      const web = yield* session.create({ location })
+
+      yield* Effect.all([
+        db.update(SessionTable).set({ path: "packages/core" }).where(eq(SessionTable.id, core.id)).run(),
+        db.update(SessionTable).set({ path: "packages/core/test" }).where(eq(SessionTable.id, nested.id)).run(),
+        db.update(SessionTable).set({ path: "packages/web" }).where(eq(SessionTable.id, web.id)).run(),
+      ]).pipe(Effect.orDie)
+
+      const listed = yield* session.list({
+        project: ProjectV2.ID.global,
+        subpath: RelativePath.make("packages/core"),
+      })
+
+      expect(new Set(listed.map((item) => item.id))).toEqual(new Set([core.id, nested.id]))
+    }),
+  )
+
+  it.effect("treats wildcard characters in subpaths literally", () =>
+    Effect.gen(function* () {
+      const session = yield* SessionV2.Service
+      const { db } = yield* Database.Service
+      const exact = yield* session.create({ location })
+      const nested = yield* session.create({ location })
+      const sibling = yield* session.create({ location })
+
+      yield* Effect.all([
+        db.update(SessionTable).set({ path: "packages/core_test" }).where(eq(SessionTable.id, exact.id)).run(),
+        db.update(SessionTable).set({ path: "packages/core_test/unit" }).where(eq(SessionTable.id, nested.id)).run(),
+        db.update(SessionTable).set({ path: "packages/coreXtest/unit" }).where(eq(SessionTable.id, sibling.id)).run(),
+      ]).pipe(Effect.orDie)
+
+      const listed = yield* session.list({
+        project: ProjectV2.ID.global,
+        subpath: RelativePath.make("packages/core_test"),
+      })
+
+      const ids = listed.map((item) => item.id)
+      expect(ids).toContain(exact.id)
+      expect(ids).toContain(nested.id)
+      expect(ids).not.toContain(sibling.id)
+    }),
+  )
+})

packages/core/test/session-logging.test.ts

@@ -1,30 +0,0 @@
-import { describe, expect, test } from "bun:test"
-import { Cause, Effect, Logger } from "effect"
-import { logFailure } from "@opencode-ai/core/session/logging"
-import { SessionSchema } from "@opencode-ai/core/session/schema"
-
-describe("Session logging", () => {
-  for (const message of ["Failed to drain Session", "Failed to wake Session"] as const) {
-    test(`renders the cause for ${message}`, async () => {
-      const entries: Array<ReturnType<typeof Logger.formatStructured.log>> = []
-      const logger = Logger.formatStructured.pipe(
-        Logger.map((entry): void => {
-          entries.push(entry)
-        }),
-      )
-
-      await logFailure(
-        message,
-        SessionSchema.ID.make("session-123"),
-        Cause.fail({ _tag: "SessionFailure", detail: { code: "nested-code" } }),
-      ).pipe(Effect.provide(Logger.layer([logger])), Effect.runPromise)
-
-      expect(entries).toHaveLength(1)
-      expect(entries[0]?.message).toBe(message)
-      expect(entries[0]?.annotations).toEqual({ sessionID: "session-123" })
-      expect(entries[0]?.cause).toContain("SessionFailure")
-      expect(entries[0]?.cause).toContain("nested-code")
-      expect(entries[0]?.cause).not.toContain("[Object")
-    })
-  }
-})

packages/core/test/session-projector.test.ts

@@ -21,10 +21,7 @@ import { SessionStore } from "@opencode-ai/core/session/store"
 import { SessionInputTable, SessionMessageTable, SessionTable } from "@opencode-ai/core/session/sql"
 import { testEffect } from "./lib/effect"
 
-const database = Database.layerFromPath(":memory:")
-const events = EventV2.layer.pipe(Layer.provide(database))
-const projector = SessionProjector.layer.pipe(Layer.provide(events), Layer.provide(database))
-const it = testEffect(Layer.mergeAll(database, events, projector))
+const it = testEffect(Layer.mergeAll(Database.defaultLayer, EventV2.defaultLayer, SessionProjector.defaultLayer))
 const sessionID = SessionV2.ID.make("ses_projector_test")
 const created = DateTime.makeUnsafe(0)
 const model = { id: ModelV2.ID.make("model"), providerID: ProviderV2.ID.make("provider") }
@@ -113,10 +110,10 @@ describe("SessionProjector", () => {
     }).pipe(
       Effect.provide(
         SessionV2.layer.pipe(
-          Layer.provide(events),
-          Layer.provide(database),
+          Layer.provide(EventV2.defaultLayer),
+          Layer.provide(Database.defaultLayer),
           Layer.provide(Project.defaultLayer),
-          Layer.provide(SessionStore.layer.pipe(Layer.provide(database))),
+          Layer.provide(SessionStore.defaultLayer),
           Layer.provide(SessionExecution.noopLayer),
         ),
       ),