refactor(app): establish v2 session controller

.opencode/plugins/tui/discovery-smoke.ts

@@ -2,12 +2,15 @@ import type { Context } from "../../../packages/plugin/src/tui/context"
 
 export default {
   id: "test.tui-discovery-smoke",
-  setup(_context: Context) {
-    // context.ui.toast.show({
-    //   title: "TUI plugin discovery works",
-    //   message: "Loaded .opencode/plugins/tui/discovery-smoke.ts",
-    //   variant: "success",
-    //   duration: 30_000,
-    // })
+  setup(context: Context) {
+    const timer = setTimeout(() => {
+      context.ui.toast.show({
+        title: "TUI plugin discovery works",
+        message: "Loaded .opencode/plugins/tui/discovery-smoke.ts",
+        variant: "success",
+        duration: 30_000,
+      })
+    }, 1_000)
+    return () => clearTimeout(timer)
   },
 }

bun.lock

@@ -600,7 +600,6 @@
         "zod": "catalog:",
       },
       "devDependencies": {
-        "@opencode-ai/theme": "workspace:*",
         "@opentui/core": "catalog:",
         "@opentui/keymap": "catalog:",
         "@opentui/solid": "catalog:",
@@ -612,14 +611,12 @@
         "typescript": "catalog:",
       },
       "peerDependencies": {
-        "@opencode-ai/theme": "workspace:*",
         "@opentui/core": ">=0.4.5",
         "@opentui/keymap": ">=0.4.5",
         "@opentui/solid": ">=0.4.5",
         "solid-js": ">=1.9.0",
       },
       "optionalPeers": [
-        "@opencode-ai/theme",
         "@opentui/core",
         "@opentui/keymap",
         "@opentui/solid",

docs/design/v1-v2-database-migration.md

@@ -1,118 +0,0 @@
-# V1 to V2 Database Migration
-
-## Approach
-
-- Use the `dev` branch database schema and migration registry as the V1 baseline.
-- Remove migrations that exist only on the V2 branch.
-- Generate one canonical migration from the `dev` schema to the final V2 schema.
-- Add explicit data operations to that migration where generated DDL is insufficient.
-- Test the migration against a populated database at the exact `dev` schema.
-
-## Preserve
-
-The canonical V1 data remains in its existing tables. In particular, preserve `session`, `message`, and `part` rows.
-
-Preserve `workspace` rows and existing `session.workspace_id` values unchanged. The migration must not clear or rebuild
-workspace relationships.
-
-Keep the `todo` table and its data unchanged. V2 does not currently migrate todos into another representation, and the
-generated migration must not drop the table.
-
-## Truncate
-
-Truncate these pre-launch V2 tables before applying schema changes:
-
-- `event`
-- `event_sequence`
-- `session_message`
-
-These rows are not canonical V1 data. Truncating `event` before adding the required `event.created` column means the
-column needs neither a backfill nor a default. After truncation, rebuild `session_message` from canonical V1 `message`
-and `part` rows rather than retaining its pre-launch V2 contents.
-
-## Message Backfill
-
-Backfill canonical V1 history from `message` and `part` into `session_message`. This is the main data transformation in
-the migration. Preserving the V1 tables alone keeps the data safe but does not make existing history visible through the
-V2 session APIs, which read `session_message`.
-
-Reuse each V1 `message.id` as the corresponding `session_message.id`. Stable IDs keep the migration deterministic and
-avoid rewriting other persisted state that may refer to a message.
-
-Within each session, order V1 messages by `time_created` and then `id`, matching the existing V1 message index. Assign
-contiguous `session_message.seq` values starting at `0`.
-
-Map ordinary V1 messages one-to-one by role. Each ordinary V1 user message becomes one V2 `user` row, and each ordinary
-V1 assistant message becomes one V2 `assistant` row. Fold the source message's ordered V1 parts into that row's V2
-payload.
-
-Handle semantic marker parts before applying the ordinary mapping. In particular, a V1 user message containing a
-`compaction` part and its paired assistant summary represent one compaction operation, not two ordinary messages. Special
-part mappings must be decided explicitly before implementing the backfill.
-
-V1 synthetic content is represented by user text parts with `synthetic: true`, not by a separate message role. A V1 user
-message whose visible text parts are all synthetic should become a V2 `synthetic` message. If a V1 user message mixes
-ordinary and synthetic content, preserve the ordinary content in the V2 `user` row and emit the synthetic content as an
-adjacent V2 `synthetic` row. Ignore text parts marked `ignored`, matching V1 model-history behavior.
-
-Use the V1 compaction user message ID as the ID of the collapsed V2 compaction message. This matches V2's use of the
-admitted compaction input ID and preserves references to the initiating message.
-
-For a completed compaction, create one V2 `compaction` row with `status: "completed"`. Set `reason` from the V1
-compaction part's `auto` flag, join the paired summary assistant's nonempty text parts with blank lines for `summary`, and
-serialize the retained V1 tail beginning at `tail_start_id` for `recent`. Use an empty `recent` value when no tail was
-retained, and use the compaction user message creation time. Do not emit the paired summary assistant as a separate V2
-assistant row.
-
-After rebuilding `session_message`, seed `event_sequence` with one row per migrated session. Set its watermark to that
-session's maximum backfilled `session_message.seq`. This prevents new V2 events from reusing sequence numbers or sorting
-before migrated history. The `event` table remains empty.
-
-## Drop
-
-Drop these pre-launch V2 tables without preserving or transforming their rows:
-
-- `session_input`
-- `session_context_epoch`
-
-Do not transfer `session_input` rows into `session_pending`.
-
-## Create Empty
-
-Let the generated migration create these tables empty:
-
-- `instruction_blob`
-- `instruction_entry`
-- `instruction_state`
-- `session_pending`
-- `kv`
-
-V1 has no canonical data to backfill into these tables. V2 initializes their state as it runs.
-
-## Fork Storage
-
-V1 has no fork-boundary state to backfill. New V2 forks use a required message boundary and persist it in
-`session.fork_boundary`. The durable fork event contains no parent sequence. Its resolved boundary is one of:
-
-- `before`: copy messages before the identified message.
-- `through`: copy messages through the identified message.
-
-Forking an empty session is not supported. `session.fork_seq` and `session.fork_message_id` are not part of the final V2
-schema.
-
-New nullable session columns, including `fork_session_id`, `fork_boundary`, and `time_suspended`, require no explicit
-backfill. Existing rows naturally receive `NULL` when the generated migration adds the columns.
-
-## Verification
-
-The canonical migration test should seed representative V1 sessions, messages, parts, todos, projects, accounts,
-credentials, permissions, shares, and workspaces. After migration, it should verify:
-
-- Preserved rows and encoded values remain unchanged.
-- Todo rows remain available in the unchanged `todo` table.
-- `event` is empty, and stale pre-launch rows are absent from the rebuilt projections.
-- Backfilled `session_message` rows represent the canonical V1 `message` and `part` history.
-- Each migrated session's `event_sequence` watermark matches its maximum backfilled message sequence.
-- Dropped tables no longer exist.
-- New tables exist and are empty.
-- The final schema has no ungenerated changes.

packages/ai/AGENTS.md

@@ -46,7 +46,7 @@ const response = yield * LLMClient.generate(request)
 
 `LLM.request(...)` builds an `LLMRequest`. `LLMClient.generate(...)` reads the executable route carried by `request.model.route`, builds the provider-native body, asks the route's transport for a real `HttpClientRequest.HttpClientRequest`, sends it through `RequestExecutor.Service`, parses the provider stream into common `LLMEvent`s, and finally returns an `LLMResponse`.
 
-Use `LLMClient.stream(request)` when callers want incremental `LLMEvent`s. Use `LLMClient.generate(request)` when callers want those same events collected into an `LLMResponse`.
+Use `LLMClient.stream(request)` when callers want incremental `LLMEvent`s. Use `LLMClient.generate(request)` when callers want those same events collected into an `LLMResponse`. Use `LLMClient.prepare<Body>(request)` to compile a request through the route pipeline without sending it — the optional `Body` type argument narrows `.body` to the route's native shape (e.g. `prepare<OpenAIChatBody>(...)` returns a `PreparedRequestOf<OpenAIChatBody>`). The runtime body is identical; the generic is a type-level assertion.
 
 Filter or narrow `LLMEvent` streams with `LLMEvent.is.*` (camelCase guards, e.g. `events.filter(LLMEvent.is.toolCall)`). The kebab-case `LLMEvent.guards["tool-call"]` form also works but prefer `is.*` in new code.
 
@@ -138,13 +138,13 @@ packages/ai/src/
     ids.ts                  branded IDs, literal types, ProviderMetadata
     options.ts              Generation/Provider/Http options, Limits, Model, cache policy
     messages.ts             content parts, Message, ToolDefinition, LLMRequest
-    events.ts               Usage, individual events, LLMEvent, LLMResponse
+    events.ts               Usage, individual events, LLMEvent, PreparedRequest, LLMResponse
     errors.ts               error reasons, LLMError, ToolFailure
     index.ts                barrel
   llm.ts                    request constructors and convenience helpers
   route/
     index.ts                @opencode-ai/ai/route advanced barrel
-    client.ts               Route.make + LLMClient.stream/generate
+    client.ts               Route.make + LLMClient.prepare/stream/generate
     executor.ts             RequestExecutor service + transport error mapping
     protocol.ts             Protocol type + Protocol.make
     endpoint.ts             Endpoint type + Endpoint.path

packages/ai/README.md

@@ -196,6 +196,7 @@ The hosted result is represented as a provider-executed tool call and tool resul
 - **`LLM.generate` / `LLM.stream`** — re-exported from `LLMClient` for one-import use.
 - **`Message.user(...)` / `Message.assistant(...)` / `Message.tool(...)`** — message constructors from the canonical schema model.
 - **`Model.make(...)` / `ToolCallPart.make(...)` / `ToolResultPart.make(...)` / `ToolDefinition.make(...)`** — model and tool-related constructors from the canonical schema model.
+- **`LLMClient.prepare(request)`** — compile a request through protocol body construction, validation, and HTTP preparation without sending. Useful for inspection and testing.
 - **`LLMEvent.is.*`** — typed guards (`is.textDelta`, `is.toolCall`, `is.finish`, …) for filtering streams.
 - **`Image.generate({...})`** — generate images through a provider-neutral image request and response model.
 - **`ImageClient`** — Effect service and layer for image execution, parallel to `LLMClient`.

packages/ai/example/call-sites.md

@@ -568,7 +568,7 @@ App boundary = explicit durable-config -> typed-provider call
       calling `.model(...)`.
 - [x] Remove request-shaping defaults from `Model`; selected models now carry only
       id, provider, and configured route while defaults live on routes or requests.
-- [x] Rework `LLMClient.stream` / `generate` to read
+- [x] Rework `LLMClient.prepare` / `stream` / `generate` to read
       `request.model.route` directly instead of calling `registeredRoute(...)`.
 - [x] Remove `Route.make(...)` global registration from the normal execution
       path; keep route ids only as diagnostics/provider API labels.

packages/ai/example/tutorial.ts

@@ -50,6 +50,18 @@ const request = LLM.request({
   },
 })
 
+// `http` is intentionally not needed for normal calls. This shows the shape for
+// newly released provider fields before they deserve a typed provider option.
+const rawOverlayExample = LLM.request({
+  model,
+  prompt: "Show the final HTTP overlay shape.",
+  http: {
+    body: { metadata: { example: "tutorial" } },
+    headers: { "x-opencode-tutorial": "1" },
+    query: { debug: "1" },
+  },
+})
+
 // 3. `generate` sends the request and collects the event stream into one
 // response object. `response.text` is the collected text output.
 const generateOnce = Effect.gen(function* () {
@@ -210,15 +222,33 @@ const FakeEcho = {
   }),
 }
 
+// `LLMClient.prepare` is the lower-level inspection hook: it compiles through
+// body conversion, validation, endpoint, auth, and HTTP construction without
+// sending anything over the network.
+const inspectFakeProvider = Effect.gen(function* () {
+  const prepared = yield* LLMClient.prepare(
+    LLM.request({
+      model: FakeEcho.configure().model("tiny-echo"),
+      prompt: "Show me the provider pipeline.",
+    }),
+  )
+
+  console.log("\n== fake provider prepare ==")
+  console.log("route:", prepared.route)
+  console.log("body:", Formatter.formatJson(prepared.body, { space: 2 }))
+})
+
 // Provide the LLM runtime and the HTTP request executor once. Keep one path
-// enabled at a time so the tutorial can demonstrate generate, stream, or
-// tool-loop behavior without spending tokens on every example.
+// enabled at a time so the tutorial can demonstrate generate, prepare, stream,
+// or tool-loop behavior without spending tokens on every example.
 const requestExecutorLayer = RequestExecutor.fetchLayer
 const llmDeps = Layer.mergeAll(requestExecutorLayer, WebSocketExecutor.layer)
 const llmClientLayer = LLMClient.layer.pipe(Layer.provide(llmDeps))
 
 const program = Effect.gen(function* () {
   // yield* generateOnce
+  // yield* inspectFakeProvider
+  // yield* LLMClient.prepare(rawOverlayExample).pipe(Effect.andThen((prepared) => Effect.sync(() => console.log(prepared.body))))
   // yield* streamText
   // yield* generateStructuredObject
   // yield* generateDynamicObject.pipe(Effect.andThen((response) => Effect.sync(() => console.log(response.object))))

packages/ai/src/llm.ts

@@ -9,28 +9,25 @@ import {
   LLMRequest,
   LLMResponse,
   Message,
-  Model,
   SystemPart,
   ToolChoice,
   ToolDefinition,
   type ContentPart,
-  type ModelProviderOptions,
 } from "./schema"
 import { make as makeTool, toDefinitions, type ToolSchema } from "./tool"
 
 /** Input accepted by `LLM.request`, normalized into the canonical `LLMRequest` class. */
-export type RequestInput<SelectedModel extends Model = Model> = Omit<
+export type RequestInput = Omit<
   ConstructorParameters<typeof LLMRequest>[0],
-  "model" | "system" | "messages" | "tools" | "toolChoice" | "generation" | "http" | "providerOptions"
+  "system" | "messages" | "tools" | "toolChoice" | "generation" | "http" | "providerOptions"
 > & {
-  readonly model: SelectedModel
   readonly system?: string | SystemPart | ReadonlyArray<SystemPart>
   readonly prompt?: string | ContentPart | ReadonlyArray<ContentPart>
   readonly messages?: ReadonlyArray<Message | Message.Input>
   readonly tools?: ReadonlyArray<ToolDefinition.Input>
   readonly toolChoice?: ToolChoice.Input
   readonly generation?: GenerationOptions.Input
-  readonly providerOptions?: NoInfer<ModelProviderOptions<SelectedModel>>
+  readonly providerOptions?: ConstructorParameters<typeof LLMRequest>[0]["providerOptions"]
   readonly http?: HttpOptions.Input
 }
 
@@ -38,7 +35,7 @@ export const generate = LLMClient.generate
 
 export const stream = LLMClient.stream
 
-export const request = <const SelectedModel extends Model>(input: RequestInput<SelectedModel>) => {
+export const request = (input: RequestInput) => {
   const {
     system: requestSystem,
     prompt,
@@ -66,7 +63,7 @@ const GENERATE_OBJECT_TOOL_NAME = "generate_object"
 
 const GENERATE_OBJECT_TOOL_DESCRIPTION = "Return the structured result by calling this tool."
 
-type GenerateObjectBase<SelectedModel extends Model = Model> = Omit<RequestInput<SelectedModel>, "tools" | "toolChoice">
+type GenerateObjectBase = Omit<RequestInput, "tools" | "toolChoice">
 
 export class GenerateObjectResponse<T> {
   constructor(
@@ -83,13 +80,11 @@ export class GenerateObjectResponse<T> {
   }
 }
 
-export interface GenerateObjectOptions<S extends ToolSchema<any>, SelectedModel extends Model = Model>
-  extends GenerateObjectBase<SelectedModel> {
+export interface GenerateObjectOptions<S extends ToolSchema<any>> extends GenerateObjectBase {
   readonly schema: S
 }
 
-export interface GenerateObjectDynamicOptions<SelectedModel extends Model = Model>
-  extends GenerateObjectBase<SelectedModel> {
+export interface GenerateObjectDynamicOptions extends GenerateObjectBase {
   /** Raw JSON Schema object describing the expected output shape. */
   readonly jsonSchema: JsonSchema.JsonSchema
 }
@@ -142,11 +137,11 @@ const runGenerateObject = Effect.fn("LLM.generateObject")(function* (
  * 2. `jsonSchema: JsonSchema.JsonSchema` — `.object` is `unknown`. Use when
  *    the schema is only available at runtime (MCP, plugin manifests). Caller validates.
  */
-export function generateObject<const SelectedModel extends Model, S extends ToolSchema<any>>(
-  options: GenerateObjectOptions<S, SelectedModel>,
+export function generateObject<S extends ToolSchema<any>>(
+  options: GenerateObjectOptions<S>,
 ): Effect.Effect<GenerateObjectResponse<Schema.Schema.Type<S>>, LLMError>
-export function generateObject<const SelectedModel extends Model>(
-  options: GenerateObjectDynamicOptions<SelectedModel>,
+export function generateObject(
+  options: GenerateObjectDynamicOptions,
 ): Effect.Effect<GenerateObjectResponse<unknown>, LLMError>
 export function generateObject(options: GenerateObjectOptions<ToolSchema<any>> | GenerateObjectDynamicOptions) {
   if ("schema" in options) {

packages/ai/src/provider-package.ts

@@ -1,4 +1,4 @@
-import type { Model, ProviderOptions } from "./schema"
+import type { Model } from "./schema"
 
 export interface Settings extends Readonly<Record<string, unknown>> {
   readonly headers?: Readonly<Record<string, string>>
@@ -9,11 +9,8 @@ export interface Settings extends Readonly<Record<string, unknown>> {
   }
 }
 
-export interface Definition<
-  ProviderSettings extends Settings = Settings,
-  Options extends ProviderOptions = ProviderOptions,
-> {
-  readonly model: (modelID: string, settings: ProviderSettings) => Model<Options>
+export interface Definition<ProviderSettings extends Settings = Settings> {
+  readonly model: (modelID: string, settings: ProviderSettings) => Model
 }
 
 export * as ProviderPackage from "./provider-package"

packages/ai/src/providers/anthropic-compatible.ts

@@ -47,7 +47,7 @@ export const configure = (input: Config) => {
   })
   return {
     id: ProviderID.make(provider),
-    model: (modelID: string | ModelID) => route.model<AnthropicMessages.ProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) => route.model({ id: modelID }),
     configure,
   }
 }
@@ -57,10 +57,7 @@ export const provider = {
   configure,
 }
 
-export const model: ProviderPackage.Definition<Settings, AnthropicMessages.ProviderOptionsInput>["model"] = (
-  modelID,
-  settings,
-) => {
+export const model: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) => {
   if (settings.apiKey !== undefined && settings.authToken !== undefined)
     throw new Error("Anthropic-compatible apiKey cannot be combined with authToken")
   return configure({

packages/ai/src/providers/anthropic.ts

@@ -52,10 +52,7 @@ export const configure = (input: Config = {}) => {
 }
 
 export const provider = configure()
-export const model: ProviderPackage.Definition<Settings, AnthropicMessages.ProviderOptionsInput>["model"] = (
-  modelID,
-  settings,
-) => {
+export const model: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) => {
   if (settings.apiKey !== undefined && settings.authToken !== undefined)
     throw new Error("Anthropic apiKey cannot be combined with authToken")
   return configure({

packages/ai/src/providers/azure.ts

@@ -99,14 +99,10 @@ export const configure = (input: Config) => {
   const modelDefaults = defaults(input)
 
   const responses = (modelID: string | ModelID) =>
-    configuredResponsesRoute
-      .with(withOpenAIOptions(modelID, modelDefaults))
-      .model<OpenAIProviderOptionsInput>({ id: modelID })
+    configuredResponsesRoute.with(withOpenAIOptions(modelID, modelDefaults)).model({ id: modelID })
 
   const chat = (modelID: string | ModelID) =>
-    configuredChatRoute
-      .with(withOpenAIOptions(modelID, modelDefaults))
-      .model<OpenAIProviderOptionsInput>({ id: modelID })
+    configuredChatRoute.with(withOpenAIOptions(modelID, modelDefaults)).model({ id: modelID })
 
   return {
     id,
@@ -137,12 +133,8 @@ const config = (settings: Settings): Config => {
   throw new Error("Azure requires resourceName or baseURL")
 }
 
-export const responsesModel: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  settings,
-) => configure(config(settings)).responses(modelID)
-export const chatModel: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  settings,
-) => configure(config(settings)).chat(modelID)
+export const responsesModel: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) =>
+  configure(config(settings)).responses(modelID)
+export const chatModel: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) =>
+  configure(config(settings)).chat(modelID)
 export const model = responsesModel

packages/ai/src/providers/cloudflare.ts

@@ -4,7 +4,6 @@ import { Auth } from "../route/auth"
 import { AuthOptions, type AtLeastOne, type ProviderAuthOption } from "../route/auth-options"
 import type { RouteDefaultsInput } from "../route/client"
 import { ProviderID, type ModelID } from "../schema"
-import type { OpenAIProviderOptionsInput } from "./openai-options"
 
 export const aiGatewayID = ProviderID.make("cloudflare-ai-gateway")
 export const workersAIID = ProviderID.make("cloudflare-workers-ai")
@@ -21,11 +20,10 @@ type GatewayURL = AtLeastOne<{
 }
 
 export type AIGatewayOptions = GatewayURL &
-  Omit<RouteDefaultsInput, "providerOptions"> &
+  RouteDefaultsInput &
   ProviderAuthOption<"optional"> & {
     /** Cloudflare AI Gateway authentication token. Sent as `cf-aig-authorization`. */
     readonly gatewayApiKey?: CloudflareSecret
-    readonly providerOptions?: OpenAIProviderOptionsInput
   }
 
 type WorkersAIURL = AtLeastOne<{
@@ -33,11 +31,7 @@ type WorkersAIURL = AtLeastOne<{
   readonly baseURL: string
 }>
 
-export type WorkersAIOptions = WorkersAIURL &
-  Omit<RouteDefaultsInput, "providerOptions"> &
-  ProviderAuthOption<"optional"> & {
-    readonly providerOptions?: OpenAIProviderOptionsInput
-  }
+export type WorkersAIOptions = WorkersAIURL & RouteDefaultsInput & ProviderAuthOption<"optional">
 
 export const aiGatewayBaseURL = (input: GatewayURL) => {
   if (input.baseURL) return input.baseURL
@@ -104,7 +98,7 @@ const configureAIGateway = (options: AIGatewayOptions) => {
   })
   return {
     id: aiGatewayID,
-    model: (modelID: string | ModelID) => route.model<OpenAIProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) => route.model({ id: modelID }),
     configure: configureAIGateway,
   }
 }
@@ -117,7 +111,7 @@ const configureWorkersAI = (options: WorkersAIOptions) => {
   })
   return {
     id: workersAIID,
-    model: (modelID: string | ModelID) => route.model<OpenAIProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) => route.model({ id: modelID }),
     configure: configureWorkersAI,
   }
 }

packages/ai/src/providers/github-copilot.ts

@@ -50,11 +50,9 @@ export const configure = (options: ModelOptions) => {
   const responsesRoute = configuredResponsesRoute(options)
   const chatRoute = configuredChatRoute(options)
   const responses = (modelID: string | ModelID) =>
-    responsesRoute
-      .with(withOpenAIOptions(modelID, defaults(options)))
-      .model<OpenAIProviderOptionsInput>({ id: modelID })
+    responsesRoute.with(withOpenAIOptions(modelID, defaults(options))).model({ id: modelID })
   const chat = (modelID: string | ModelID) =>
-    chatRoute.with(withOpenAIOptions(modelID, defaults(options))).model<OpenAIProviderOptionsInput>({ id: modelID })
+    chatRoute.with(withOpenAIOptions(modelID, defaults(options))).model({ id: modelID })
   return {
     id,
     model: (modelID: string | ModelID) =>

packages/ai/src/providers/google-vertex-chat.ts

@@ -1,9 +1,8 @@
 import type { ProviderPackage } from "../provider-package"
 import { OpenAICompatibleChat } from "../protocols/openai-compatible-chat"
 import type { RouteDefaultsInput } from "../route/client"
-import { ProviderID, type ModelID } from "../schema"
+import { ProviderID, type ModelID, type ProviderOptions } from "../schema"
 import { GoogleVertexShared } from "./google-vertex-shared"
-import type { OpenAIProviderOptionsInput } from "./openai-options"
 
 export const id = ProviderID.make("google-vertex")
 
@@ -12,7 +11,6 @@ export type Config = RouteDefaultsInput &
     readonly baseURL?: string
     readonly location?: string
     readonly project?: string
-    readonly providerOptions?: OpenAIProviderOptionsInput
   }
 
 export interface Settings extends ProviderPackage.Settings {
@@ -21,7 +19,7 @@ export interface Settings extends ProviderPackage.Settings {
   readonly baseURL?: string
   readonly location?: string
   readonly project?: string
-  readonly providerOptions?: OpenAIProviderOptionsInput
+  readonly providerOptions?: ProviderOptions
 }
 
 const route = OpenAICompatibleChat.route.with({
@@ -58,7 +56,7 @@ export const configure = (input: Config = {}) => {
   const route = configuredRoute(input)
   return {
     id,
-    model: (modelID: string | ModelID) => route.model<OpenAIProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) => route.model({ id: modelID }),
     configure,
   }
 }
@@ -68,7 +66,7 @@ export const provider = {
   configure,
 }
 
-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) => {
+export const model: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) => {
   if (settings.apiKey !== undefined) throw new Error("Google Vertex Chat does not support API keys")
   return configure({
     accessToken: settings.accessToken,

packages/ai/src/providers/google-vertex-messages.ts

@@ -91,7 +91,7 @@ export const configure = (input: Config = {}) => {
   const route = configuredRoute(input)
   return {
     id,
-    model: (modelID: string | ModelID) => route.model<AnthropicMessages.ProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) => route.model({ id: modelID }),
     configure,
   }
 }
@@ -101,10 +101,7 @@ export const provider = {
   configure,
 }
 
-export const model: ProviderPackage.Definition<Settings, AnthropicMessages.ProviderOptionsInput>["model"] = (
-  modelID,
-  settings,
-) => {
+export const model: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) => {
   if (settings.apiKey !== undefined) throw new Error("Google Vertex Messages does not support API keys")
   return configure({
     accessToken: settings.accessToken,

packages/ai/src/providers/google-vertex-responses.ts

@@ -1,9 +1,8 @@
 import type { ProviderPackage } from "../provider-package"
 import { OpenAICompatibleResponses } from "../protocols/openai-compatible-responses"
 import type { RouteDefaultsInput } from "../route/client"
-import { ProviderID, type ModelID } from "../schema"
+import { ProviderID, type ModelID, type ProviderOptions } from "../schema"
 import { GoogleVertexShared } from "./google-vertex-shared"
-import type { OpenResponsesProviderOptionsInput } from "./open-responses-options"
 
 export const id = ProviderID.make("google-vertex")
 
@@ -12,7 +11,6 @@ export type Config = RouteDefaultsInput &
     readonly baseURL?: string
     readonly location?: string
     readonly project?: string
-    readonly providerOptions?: OpenResponsesProviderOptionsInput
   }
 
 export interface Settings extends ProviderPackage.Settings {
@@ -21,7 +19,7 @@ export interface Settings extends ProviderPackage.Settings {
   readonly baseURL?: string
   readonly location?: string
   readonly project?: string
-  readonly providerOptions?: OpenResponsesProviderOptionsInput
+  readonly providerOptions?: ProviderOptions
 }
 
 const route = OpenAICompatibleResponses.route.with({
@@ -60,7 +58,7 @@ export const configure = (input: Config = {}) => {
   const route = configuredRoute(input)
   return {
     id,
-    model: (modelID: string | ModelID) => route.model<OpenResponsesProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) => route.model({ id: modelID }),
     configure,
   }
 }
@@ -70,10 +68,7 @@ export const provider = {
   configure,
 }
 
-export const model: ProviderPackage.Definition<Settings, OpenResponsesProviderOptionsInput>["model"] = (
-  modelID,
-  settings,
-) => {
+export const model: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) => {
   if (settings.apiKey !== undefined) throw new Error("Google Vertex Responses does not support API keys")
   return configure({
     accessToken: settings.accessToken,

packages/ai/src/providers/google-vertex.ts

@@ -77,8 +77,7 @@ const configuredRoute = (input: Config, modelID: string | ModelID) => {
 export const configure = (input: Config = {}) => {
   return {
     id,
-    model: (modelID: string | ModelID) =>
-      configuredRoute(input, modelID).model<Gemini.ProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) => configuredRoute(input, modelID).model({ id: modelID }),
     configure,
   }
 }
@@ -87,10 +86,7 @@ export const provider = {
   id,
   configure,
 }
-export const model: ProviderPackage.Definition<Settings, Gemini.ProviderOptionsInput>["model"] = (
-  modelID,
-  settings,
-) => {
+export const model: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) => {
   if (settings.apiKey !== undefined && settings.accessToken !== undefined)
     throw new Error("Google Vertex apiKey cannot be combined with accessToken or auth")
   return configure({

packages/ai/src/providers/google.ts

@@ -50,14 +50,14 @@ export const configure = (input: Config = {}) => {
     })
   return {
     id,
-    model: (modelID: string | ModelID) => route.model<Gemini.ProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) => route.model({ id: modelID }),
     image,
     configure,
   }
 }
 
 export const provider = configure()
-export const model: ProviderPackage.Definition<Settings, Gemini.ProviderOptionsInput>["model"] = (modelID, settings) =>
+export const model: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) =>
   configure({
     apiKey: settings.apiKey,
     baseURL: settings.baseURL,

packages/ai/src/providers/openai-compatible-responses.ts

@@ -36,7 +36,7 @@ export const configure = (input: Config) => {
   })
   return {
     id: ProviderID.make(provider),
-    model: (modelID: string | ModelID) => route.model<OpenResponsesProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) => route.model({ id: modelID }),
     configure,
   }
 }
@@ -46,10 +46,7 @@ export const provider = {
   configure,
 }
 
-export const model: ProviderPackage.Definition<Settings, OpenResponsesProviderOptionsInput>["model"] = (
-  modelID,
-  settings,
-) =>
+export const model: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) =>
   configure({
     apiKey: settings.apiKey,
     baseURL: settings.baseURL,

packages/ai/src/providers/openai-compatible.ts

@@ -4,15 +4,13 @@ import type { RouteDefaultsInput } from "../route/client"
 import { AuthOptions, type ProviderAuthOption } from "../route/auth-options"
 import type { ProviderPackage } from "../provider-package"
 import { profiles, type OpenAICompatibleProfile } from "./openai-compatible-profile"
-import type { OpenAIProviderOptionsInput } from "./openai-options"
 
 export const id = ProviderID.make("openai-compatible")
 
-type GenericModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
+type GenericModelOptions = RouteDefaultsInput &
   ProviderAuthOption<"optional"> & {
     readonly provider?: string
     readonly baseURL: string
-    readonly providerOptions?: OpenAIProviderOptionsInput
   }
 
 export interface Settings extends ProviderPackage.Settings {
@@ -21,10 +19,9 @@ export interface Settings extends ProviderPackage.Settings {
   readonly provider?: string
 }
 
-export type FamilyModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
+export type FamilyModelOptions = RouteDefaultsInput &
   ProviderAuthOption<"optional"> & {
     readonly baseURL?: string
-    readonly providerOptions?: OpenAIProviderOptionsInput
   }
 
 export const routes = [OpenAICompatibleChat.route]
@@ -40,8 +37,7 @@ export const configure = (input: GenericModelOptions) => {
   })
   return {
     id: ProviderID.make(provider),
-    model: (modelID: string | ModelID) =>
-      route.model<OpenAIProviderOptionsInput>({ id: modelID, provider: ProviderID.make(provider) }),
+    model: (modelID: string | ModelID) => route.model({ id: modelID, provider: ProviderID.make(provider) }),
     configure,
   }
 }
@@ -67,7 +63,7 @@ export const provider = {
   configure,
 }
 
-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) =>
+export const model: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) =>
   configure({
     apiKey: settings.apiKey,
     baseURL: settings.baseURL,

packages/ai/src/providers/openai.ts

@@ -86,15 +86,10 @@ export const configure = (input: Config = {}) => {
   const chatRoute = configuredRoute(OpenAIChat.route, input)
   const modelDefaults = defaults(input)
   const responses = (id: string | ModelID) =>
-    responsesRoute
-      .with(withOpenAIOptions(id, modelDefaults, { textVerbosity: true }))
-      .model<OpenAIProviderOptionsInput>({ id })
+    responsesRoute.with(withOpenAIOptions(id, modelDefaults, { textVerbosity: true })).model({ id })
   const responsesWebSocket = (id: string | ModelID) =>
-    responsesWebSocketRoute
-      .with(withOpenAIOptions(id, modelDefaults, { textVerbosity: true }))
-      .model<OpenAIProviderOptionsInput>({ id })
-  const chat = (id: string | ModelID) =>
-    chatRoute.with(withOpenAIOptions(id, modelDefaults)).model<OpenAIProviderOptionsInput>({ id })
+    responsesWebSocketRoute.with(withOpenAIOptions(id, modelDefaults, { textVerbosity: true })).model({ id })
+  const chat = (id: string | ModelID) => chatRoute.with(withOpenAIOptions(id, modelDefaults)).model({ id })
   const image = (modelID: string | ModelID) =>
     OpenAIImages.model({
       id: modelID,
@@ -137,17 +132,15 @@ const config = (settings: Settings): Config => {
   }
 }
 
-export const model: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (modelID, settings) => {
+export const model: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) => {
   const configured = configure(config(settings))
   if (settings.transport === undefined || settings.transport === "http") return configured.responses(modelID)
   if (settings.transport === "websocket") return configured.responsesWebSocket(modelID)
   throw new Error(`Unsupported OpenAI Responses transport: ${String(settings.transport)}`)
 }
 
-export const chatModel: ProviderPackage.Definition<Settings, OpenAIProviderOptionsInput>["model"] = (
-  modelID,
-  settings,
-) => configure(config(settings)).chat(modelID)
+export const chatModel: ProviderPackage.Definition<Settings>["model"] = (modelID, settings) =>
+  configure(config(settings)).chat(modelID)
 export const responses = provider.responses
 export const responsesWebSocket = provider.responsesWebSocket
 export const chat = provider.chat

packages/ai/src/providers/openrouter.ts

@@ -107,7 +107,7 @@ export const configure = (input: ModelOptions = {}) => {
   const route = configuredRoute(input)
   return {
     id,
-    model: (modelID: string | ModelID) => route.model<OpenRouterProviderOptionsInput>({ id: modelID }),
+    model: (modelID: string | ModelID) => route.model({ id: modelID }),
     configure,
   }
 }

packages/ai/src/providers/xai.ts

@@ -5,14 +5,12 @@ import * as OpenAICompatibleProfiles from "./openai-compatible-profile"
 import * as OpenAICompatibleChat from "../protocols/openai-compatible-chat"
 import * as OpenAIResponses from "../protocols/openai-responses"
 import { XAIImages } from "../protocols/xai-images"
-import type { OpenAIProviderOptionsInput } from "./openai-options"
 
 export const id = ProviderID.make("xai")
 
-export type ModelOptions = Omit<RouteDefaultsInput, "providerOptions"> &
+export type ModelOptions = RouteDefaultsInput &
   ProviderAuthOption<"optional"> & {
     readonly baseURL?: string
-    readonly providerOptions?: OpenAIProviderOptionsInput
   }
 
 export type { XAIImageOptions } from "../protocols/xai-images"
@@ -44,8 +42,8 @@ const configuredChatRoute = (input: ModelOptions) => {
 export const configure = (input: ModelOptions = {}) => {
   const responsesRoute = configuredResponsesRoute(input)
   const chatRoute = configuredChatRoute(input)
-  const responses = (modelID: string | ModelID) => responsesRoute.model<OpenAIProviderOptionsInput>({ id: modelID })
-  const chat = (modelID: string | ModelID) => chatRoute.model<OpenAIProviderOptionsInput>({ id: modelID })
+  const responses = (modelID: string | ModelID) => responsesRoute.model({ id: modelID })
+  const chat = (modelID: string | ModelID) => chatRoute.model({ id: modelID })
   const image = (modelID: string | ModelID) =>
     XAIImages.model({
       id: modelID,

packages/ai/src/route/client.ts

@@ -10,7 +10,7 @@ import { WebSocketExecutor } from "./transport"
 import type { Protocol } from "./protocol"
 import { applyCachePolicy } from "../cache-policy"
 import * as ProviderShared from "../protocols/shared"
-import type { LLMError, ProtocolID, ProviderOptions } from "../schema"
+import type { LLMError, PreparedRequestOf, ProtocolID, ProviderOptions } from "../schema"
 import {
   GenerationOptions,
   HttpOptions,
@@ -20,6 +20,7 @@ import {
   ModelLimits,
   LLMError as LLMErrorClass,
   LLMEvent,
+  PreparedRequest,
   ProviderID,
   mergeGenerationOptions,
   mergeHttpOptions,
@@ -45,7 +46,7 @@ export interface Route<Body, Prepared = unknown> {
   readonly defaults: RouteDefaults
   readonly body: RouteBody<Body>
   readonly with: (patch: RoutePatch<Body, Prepared>) => Route<Body, Prepared>
-  readonly model: <Options extends ProviderOptions = ProviderOptions>(input: RouteMappedModelInput) => Model<Options>
+  readonly model: (input: RouteMappedModelInput) => Model
   readonly prepareTransport: (body: Body, request: LLMRequest) => Effect.Effect<Prepared, LLMError>
   readonly streamPrepared: (
     prepared: Prepared,
@@ -92,12 +93,12 @@ export interface RoutePatch<Body, Prepared> extends RouteDefaultsInput {
 
 type RouteMappedModelInput = RouteModelInput | RouteRoutedModelInput
 
-const makeRouteModel = <Options extends ProviderOptions = ProviderOptions>(route: AnyRoute, mapped: RouteMappedModelInput) => {
+const makeRouteModel = (route: AnyRoute, mapped: RouteMappedModelInput) => {
   const provider = route.provider ?? ("provider" in mapped ? mapped.provider : undefined)
   if (!provider) throw new Error(`Route.model(${route.id}) requires a provider`)
   if (!endpointBaseURL(route.endpoint))
     throw new Error(`Route.model(${route.id}) requires an endpoint baseURL — configure it on the route first`)
-  return Model.make<Options>({
+  return Model.make({
     ...mapped,
     provider,
     route,
@@ -141,6 +142,17 @@ export const httpOptions = (input: HttpOptionsInput | undefined) => {
 }
 
 export interface Interface {
+  /**
+   * Compile a request through protocol body construction, validation, and HTTP
+   * preparation without sending it. Returns the prepared request including the
+   * provider-native body.
+   *
+   * Pass a `Body` type argument to statically expose the route's body
+   * shape (e.g. `prepare<OpenAIChatBody>(...)`) — the runtime body is
+   * identical, so this is a type-level assertion the caller makes about which
+   * route the request will resolve to.
+   */
+  readonly prepare: <Body = unknown>(request: LLMRequest) => Effect.Effect<PreparedRequestOf<Body>, LLMError>
   readonly stream: StreamMethod
   readonly generate: GenerateMethod
 }
@@ -284,8 +296,7 @@ function makeFromTransport<Body, Prepared, Frame, Event, State>(
           defaults: mergeRouteDefaults(route.defaults, defaults),
         })
       },
-      model: <Options extends ProviderOptions = ProviderOptions>(input: RouteMappedModelInput) =>
-        makeRouteModel<Options>(route, input),
+      model: (input) => makeRouteModel(route, input),
       prepareTransport: (body, request) =>
         routeInput.transport.prepare({
           body,
@@ -359,6 +370,9 @@ export function make<Body, Prepared, Frame, Event, State>(
   })
 }
 
+// `compile` is the important boundary: it turns a common `LLMRequest` into a
+// validated provider body plus transport-private prepared data, but does not
+// execute transport.
 const compile = Effect.fn("LLM.compile")(function* (request: LLMRequest) {
   const resolved = applyCachePolicy(resolveRequestOptions(request))
   const route = resolved.model.route
@@ -376,17 +390,17 @@ const compile = Effect.fn("LLM.compile")(function* (request: LLMRequest) {
   }
 })
 
-/** @internal Test-only projection of the execution compiler; not exported from package barrels. */
-export const compileRequest = Effect.fn("LLM.compileRequest")(function* (request: LLMRequest) {
+const prepareWith = Effect.fn("LLMClient.prepare")(function* (request: LLMRequest) {
   const compiled = yield* compile(request)
-  return {
+
+  return new PreparedRequest({
     id: compiled.request.id ?? "request",
     route: compiled.route.id,
     protocol: compiled.route.protocol,
     model: compiled.request.model,
     body: compiled.body,
     metadata: { transport: compiled.route.transport.id },
-  }
+  })
 })
 
 const streamRequestWith = (runtime: TransportRuntime) => (request: LLMRequest) =>
@@ -408,6 +422,9 @@ const generateWith = (stream: Interface["stream"]) =>
     )
   })
 
+export const prepare = <Body = unknown>(request: LLMRequest) =>
+  prepareWith(request) as Effect.Effect<PreparedRequestOf<Body>, LLMError>
+
 export function stream(request: LLMRequest): Stream.Stream<LLMEvent, LLMError> {
   return Stream.unwrap(
     Effect.gen(function* () {
@@ -436,7 +453,7 @@ export const layer: Layer.Layer<Service, never, RequestExecutor.Service> = Layer
       http: yield* RequestExecutor.Service,
       webSocket: Option.getOrUndefined(yield* Effect.serviceOption(WebSocketExecutor.Service)),
     })
-    return Service.of({ stream, generate: generateWith(stream) })
+    return Service.of({ prepare: prepareWith as Interface["prepare"], stream, generate: generateWith(stream) })
   }),
 )
 
@@ -445,6 +462,7 @@ export const Route = { make } as const
 export const LLMClient = {
   Service,
   layer,
+  prepare,
   stream,
   generate,
 } as const

packages/ai/src/schema/events.ts

@@ -1,5 +1,6 @@
 import { Schema } from "effect"
-import { ContentBlockID, FinishReason, ProviderMetadata, ToolCallID } from "./ids"
+import { ContentBlockID, FinishReason, ProtocolID, ProviderMetadata, RouteID, ToolCallID } from "./ids"
+import { ModelSchema } from "./options"
 import { Message, ToolCallPart, ToolOutput, ToolResultPart, ToolResultValue, type ContentPart } from "./messages"
 import { ProviderFailureClassification } from "./errors"
 
@@ -313,6 +314,29 @@ export const LLMEvent = Object.assign(llmEventTagged, {
 })
 export type LLMEvent = Schema.Schema.Type<typeof llmEventTagged>
 
+export class PreparedRequest extends Schema.Class<PreparedRequest>("LLM.PreparedRequest")({
+  id: Schema.String,
+  route: RouteID,
+  protocol: ProtocolID,
+  model: ModelSchema,
+  body: Schema.Unknown,
+  metadata: Schema.optional(Schema.Record(Schema.String, Schema.Unknown)),
+}) {}
+
+/**
+ * A `PreparedRequest` whose `body` is typed as `Body`. Use with the generic
+ * on `LLMClient.prepare<Body>(...)` when the caller knows which route their
+ * request will resolve to and wants its native shape statically exposed
+ * (debug UIs, request previews, plan rendering).
+ *
+ * The runtime body is identical — the route still emits `body: unknown` — so
+ * this is a type-level assertion the caller makes about what they expect to
+ * find. The prepare runtime does not validate the assertion.
+ */
+export type PreparedRequestOf<Body> = Omit<PreparedRequest, "body"> & {
+  readonly body: Body
+}
+
 const responseText = (events: ReadonlyArray<LLMEvent>) =>
   events
     .filter(LLMEvent.is.textDelta)

packages/ai/src/schema/options.ts

@@ -178,8 +178,7 @@ export namespace ModelCompatibility {
   export const make = (input: Input) => (input instanceof ModelCompatibility ? input : new ModelCompatibility(input))
 }
 
-export class Model<Options extends ProviderOptions = ProviderOptions> {
-  declare protected readonly _ProviderOptions: Options
+export class Model {
   readonly id: ModelID
   readonly provider: ProviderID
   readonly route: AnyRoute
@@ -194,8 +193,8 @@ export class Model<Options extends ProviderOptions = ProviderOptions> {
     this.compatibility = input.compatibility
   }
 
-  static make<Options extends ProviderOptions = ProviderOptions>(input: Model.Input) {
-    return new Model<Options>({
+  static make(input: Model.Input) {
+    return new Model({
       id: ModelID.make(input.id),
       provider: ProviderID.make(input.provider),
       route: input.route,
@@ -204,7 +203,7 @@ export class Model<Options extends ProviderOptions = ProviderOptions> {
     })
   }
 
-  static input<Options extends ProviderOptions>(model: Model<Options>): Model.ConstructorInput {
+  static input(model: Model): Model.ConstructorInput {
     return {
       id: model.id,
       provider: model.provider,
@@ -214,9 +213,9 @@ export class Model<Options extends ProviderOptions = ProviderOptions> {
     }
   }
 
-  static update<Options extends ProviderOptions>(model: Model<Options>, patch: Partial<Model.Input>) {
+  static update(model: Model, patch: Partial<Model.Input>) {
     if (Object.keys(patch).length === 0) return model
-    return Model.make<Options>({
+    return Model.make({
       ...Model.input(model),
       ...patch,
     })
@@ -242,8 +241,6 @@ export namespace Model {
 
 export type ModelInput = Model.Input
 
-export type ModelProviderOptions<SelectedModel> = SelectedModel extends Model<infer Options> ? Options : never
-
 export const ModelSchema = Schema.declare((value): value is Model => value instanceof Model, { expected: "LLM.Model" })
 
 export class CacheHint extends Schema.Class<CacheHint>("LLM.CacheHint")({

packages/ai/src/testing.ts

@@ -99,6 +99,7 @@ export const layer = (options: LayerOptions = {}) =>
         )
       }) as LLMClientShape["stream"]
       const client = LLMClient.Service.of({
+        prepare: () => Effect.die("TestLLM does not prepare provider-native requests"),
         stream,
         generate: (request) =>
           stream(request).pipe(

packages/ai/test/adapter.test.ts

@@ -2,7 +2,6 @@ import { describe, expect } from "bun:test"
 import { Effect, Schema, Stream } from "effect"
 import { LLM, LLMRequest, LLMResponse } from "../src"
 import { Route, Endpoint, LLMClient, Protocol, type FramingDef } from "../src/route"
-import { compileRequest } from "../src/route/client"
 import { Model } from "../src/schema"
 import { testEffect } from "./lib/effect"
 import { dynamicResponse } from "./lib/http"
@@ -140,7 +139,8 @@ describe("llm route", () => {
 
   it.effect("selects routes by model route value", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const llm = yield* LLMClient.Service
+      const prepared = yield* llm.prepare(
         LLMRequest.update(request, { model: updateModel(request.model, { route: configuredGemini }) }),
       )
 
@@ -173,7 +173,7 @@ describe("llm route", () => {
         framing: fakeFraming,
       })
 
-      const prepared = yield* compileRequest(
+      const prepared = yield* (yield* LLMClient.Service).prepare(
         LLMRequest.update(request, { model: updateModel(request.model, { route: duplicate }) }),
       )
 

packages/ai/test/cache-policy.test.ts

@@ -1,8 +1,7 @@
 import { describe, expect, test } from "bun:test"
 import { Effect } from "effect"
 import { CacheHint, LLM, Message } from "../src"
-import { Auth } from "../src/route"
-import { compileRequest } from "../src/route/client"
+import { Auth, LLMClient } from "../src/route"
 import { AmazonBedrock } from "../src/providers"
 import * as AnthropicMessages from "../src/protocols/anthropic-messages"
 import * as Gemini from "../src/protocols/gemini"
@@ -32,7 +31,7 @@ const geminiModel = Gemini.route
 describe("applyCachePolicy", () => {
   it.effect("undefined cache resolves to 'auto' (the recommended default)", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: anthropicModel,
           system: "You are concise.",
@@ -51,7 +50,7 @@ describe("applyCachePolicy", () => {
 
   it.effect("'auto' marks the last tool, first and last system parts, and final message boundary on Anthropic", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: anthropicModel,
           system: [
@@ -88,7 +87,7 @@ describe("applyCachePolicy", () => {
 
   it.effect("'auto' is a no-op on OpenAI (implicit caching protocol)", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: openaiModel,
           system: "Sys",
@@ -107,7 +106,7 @@ describe("applyCachePolicy", () => {
 
   it.effect("'auto' is a no-op on Gemini (out-of-band caching protocol)", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: geminiModel,
           system: "Sys",
@@ -124,7 +123,7 @@ describe("applyCachePolicy", () => {
 
   it.effect("'auto' on Bedrock emits cachePoint markers in the right places", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: bedrockModel,
           system: [
@@ -158,7 +157,7 @@ describe("applyCachePolicy", () => {
 
   it.effect("'none' disables auto placement even when manual hints exist", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: anthropicModel,
           system: "Sys",
@@ -177,7 +176,7 @@ describe("applyCachePolicy", () => {
 
   it.effect("granular object form: tools-only marks just tools", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: anthropicModel,
           system: "Sys",
@@ -196,7 +195,7 @@ describe("applyCachePolicy", () => {
 
   it.effect("auto policy preserves manual CacheHints on other parts", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: anthropicModel,
           system: [
@@ -242,7 +241,7 @@ describe("applyCachePolicy", () => {
       expect("cache" in tail ? tail.cache : undefined).toBeUndefined()
       expect(applyCachePolicy(applied)).toBe(applied)
 
-      const prepared = yield* compileRequest(request)
+      const prepared = yield* LLMClient.prepare(request)
 
       const body = prepared.body as {
         tools: Array<{ cache_control?: unknown }>
@@ -262,7 +261,7 @@ describe("applyCachePolicy", () => {
 
   it.effect("ttlSeconds in the policy flows through to wire markers", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: anthropicModel,
           system: "Sys",
@@ -279,7 +278,7 @@ describe("applyCachePolicy", () => {
 
   it.effect("messages: { tail: 2 } marks the last 2 message boundaries", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: anthropicModel,
           messages: [Message.user("u1"), Message.assistant("a1"), Message.user("u2"), Message.assistant("a2")],
@@ -297,7 +296,7 @@ describe("applyCachePolicy", () => {
 
   it.effect("'latest-assistant' marks the last assistant message", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: anthropicModel,
           messages: [Message.user("u1"), Message.assistant("a1"), Message.user("u2")],

packages/ai/test/llm-option-types.types.ts

@@ -1,47 +0,0 @@
-import { Schema } from "effect"
-import { LLM, type Model, type ModelProviderOptions, type ProviderOptions } from "../src"
-import { OpenAIChat } from "../src/protocols"
-
-interface ExampleOptions {
-  readonly [key: string]: unknown
-  readonly mode?: "fast" | "thorough"
-}
-
-type ExampleProviderOptions = ProviderOptions & {
-  readonly example?: ExampleOptions
-}
-
-const model = OpenAIChat.route
-  .with({ endpoint: { baseURL: "https://example.com/v1" } })
-  .model<ExampleProviderOptions>({ id: "example" })
-
-LLM.request({ model, prompt: "Hello", providerOptions: { example: { mode: "fast" } } })
-LLM.request({ model, prompt: "Hello", providerOptions: { future: { option: true } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Known provider options preserve their value types.
-  providerOptions: { example: { mode: "slow" } },
-})
-
-LLM.generateObject({
-  model,
-  prompt: "Hello",
-  schema: Schema.Struct({ answer: Schema.String }),
-  providerOptions: { example: { mode: "thorough" } },
-})
-
-LLM.generateObject({
-  model,
-  prompt: "Hello",
-  jsonSchema: { type: "object" },
-  // @ts-expect-error Dynamic object generation uses the selected model's provider options.
-  providerOptions: { example: { mode: false } },
-})
-
-declare const generic: Model
-LLM.request({ model: generic, prompt: "Hello", providerOptions: { arbitrary: { option: true } } })
-
-const options: ModelProviderOptions<typeof model> = { example: { mode: "fast" } }
-void options

packages/ai/test/prepare.test.ts

@@ -4,7 +4,6 @@ import { HttpClientRequest } from "effect/unstable/http"
 import { LLM, mergeProviderOptions } from "../src"
 import { AnthropicMessages, OpenAIChat } from "../src/protocols"
 import { Auth, LLMClient } from "../src/route"
-import { compileRequest } from "../src/route/client"
 import { it } from "./lib/effect"
 import { dynamicResponse } from "./lib/http"
 import { deltaChunk } from "./lib/openai-chunks"
@@ -45,7 +44,7 @@ describe("request option precedence", () => {
     })
   })
 
-  it.effect("compiles bodies with route defaults, model defaults, and call options in order", () =>
+  it.effect("prepares bodies with route defaults, model defaults, and call options in order", () =>
     Effect.gen(function* () {
       const route = OpenAIChat.route.with({
         endpoint: { baseURL: "https://api.openai.test/v1/" },
@@ -60,7 +59,7 @@ describe("request option precedence", () => {
           providerOptions: { openai: { reasoningEffort: "medium" } },
         },
       })
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           prompt: "Say hello.",
@@ -142,7 +141,7 @@ describe("request option precedence", () => {
       const model = OpenAIChat.route
         .with({ endpoint: { baseURL: "https://api.openai.test/v1/" }, auth: Auth.bearer("test") })
         .model({ id: "gpt-4o-mini" })
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           model,
           prompt: "Say hello.",
@@ -165,8 +164,10 @@ describe("request option precedence", () => {
         limits: { output: 128 },
       })
       const model = route.model({ id: "claude-sonnet-4-5", defaults: { limits: { output: 64 } } })
-      const withoutMaxTokens = yield* compileRequest(LLM.request({ model, prompt: "Say hello.", cache: "none" }))
-      const withMaxTokens = yield* compileRequest(
+      const withoutMaxTokens = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
+        LLM.request({ model, prompt: "Say hello.", cache: "none" }),
+      )
+      const withMaxTokens = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLM.request({ model, prompt: "Say hello.", cache: "none", generation: { maxTokens: 32 } }),
       )
 

packages/ai/test/provider-options/anthropic-compatible.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { AnthropicCompatible } from "../../src/providers"
-
-const model = AnthropicCompatible.configure({ baseURL: "https://example.com" }).model("claude")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { anthropic: { effort: "high" } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Anthropic effort must be a string.
-  providerOptions: { anthropic: { effort: 1 } },
-})

packages/ai/test/provider-options/anthropic.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { Anthropic } from "../../src/providers"
-
-const model = Anthropic.provider.model("claude-sonnet-4-5")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { anthropic: { thinking: { type: "adaptive" } } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Anthropic thinking modes are a fixed union.
-  providerOptions: { anthropic: { thinking: { type: "automatic" } } },
-})

packages/ai/test/provider-options/azure.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { Azure } from "../../src/providers"
-
-const model = Azure.configure({ resourceName: "example" }).responses("deployment")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { openai: { store: false } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Azure OpenAI store must be boolean.
-  providerOptions: { openai: { store: "false" } },
-})

packages/ai/test/provider-options/cloudflare.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { CloudflareWorkersAI } from "../../src/providers"
-
-const model = CloudflareWorkersAI.configure({ accountId: "account", apiKey: "test" }).model("model")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { openai: { promptCacheKey: "cache" } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Cloudflare's OpenAI-compatible prompt cache key must be a string.
-  providerOptions: { openai: { promptCacheKey: 1 } },
-})

packages/ai/test/provider-options/github-copilot.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { GitHubCopilot } from "../../src/providers"
-
-const model = GitHubCopilot.configure({ baseURL: "https://example.com" }).model("gpt-5")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { openai: { reasoningSummary: "auto" } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Copilot reasoning summaries use the OpenAI union.
-  providerOptions: { openai: { reasoningSummary: "full" } },
-})

packages/ai/test/provider-options/google-vertex-chat.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { GoogleVertexChat } from "../../src/providers"
-
-const model = GoogleVertexChat.configure({ accessToken: "test", project: "project" }).model("gemini")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { openai: { serviceTier: "priority" } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Vertex OpenAI-compatible service tiers use the OpenAI union.
-  providerOptions: { openai: { serviceTier: "premium" } },
-})

packages/ai/test/provider-options/google-vertex-messages.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { GoogleVertexMessages } from "../../src/providers"
-
-const model = GoogleVertexMessages.configure({ accessToken: "test", project: "project" }).model("claude")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { anthropic: { effort: "medium" } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Vertex Anthropic effort must be a string.
-  providerOptions: { anthropic: { effort: false } },
-})

packages/ai/test/provider-options/google-vertex-responses.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { GoogleVertexResponses } from "../../src/providers"
-
-const model = GoogleVertexResponses.configure({ accessToken: "test", project: "project" }).model("gemini")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { openresponses: { textVerbosity: "high" } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Vertex Responses verbosity uses the Open Responses union.
-  providerOptions: { openresponses: { textVerbosity: "verbose" } },
-})

packages/ai/test/provider-options/google-vertex.types.ts

@@ -1,17 +0,0 @@
-import { LLM } from "../../src"
-import { GoogleVertex } from "../../src/providers"
-
-const model = GoogleVertex.provider.configure({ apiKey: "test" }).model("gemini-2.5-pro")
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  providerOptions: { gemini: { thinkingConfig: { includeThoughts: true } } },
-})
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Vertex Gemini includeThoughts must be boolean.
-  providerOptions: { gemini: { thinkingConfig: { includeThoughts: "yes" } } },
-})

packages/ai/test/provider-options/google.types.ts

@@ -1,17 +0,0 @@
-import { LLM } from "../../src"
-import { Google } from "../../src/providers"
-
-const model = Google.provider.model("gemini-2.5-pro")
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  providerOptions: { gemini: { thinkingConfig: { thinkingBudget: 1024 } } },
-})
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Gemini thinking budgets must be numeric.
-  providerOptions: { gemini: { thinkingConfig: { thinkingBudget: "large" } } },
-})

packages/ai/test/provider-options/openai-compatible-responses.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { OpenAICompatibleResponses } from "../../src/providers"
-
-const model = OpenAICompatibleResponses.configure({ baseURL: "https://example.com" }).model("model")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { openresponses: { reasoningSummary: "detailed" } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error Open Responses reasoning summaries use a fixed union.
-  providerOptions: { openresponses: { reasoningSummary: "full" } },
-})

packages/ai/test/provider-options/openai-compatible.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { OpenAICompatible } from "../../src/providers"
-
-const model = OpenAICompatible.deepseek.model("deepseek-chat")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { openai: { store: false } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error OpenAI-compatible store must be boolean.
-  providerOptions: { openai: { store: "false" } },
-})

packages/ai/test/provider-options/openai.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { OpenAI } from "../../src/providers"
-
-const model = OpenAI.responses("gpt-5")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { openai: { reasoningEffort: "high" } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error OpenAI reasoning effort must be a string.
-  providerOptions: { openai: { reasoningEffort: 1 } },
-})

packages/ai/test/provider-options/openrouter.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { OpenRouter } from "../../src/providers"
-
-const model = OpenRouter.provider.model("anthropic/claude-sonnet-4.5")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { openrouter: { usage: true } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error OpenRouter usage must be boolean or an option record.
-  providerOptions: { openrouter: { usage: "yes" } },
-})

packages/ai/test/provider-options/xai.types.ts

@@ -1,13 +0,0 @@
-import { LLM } from "../../src"
-import { XAI } from "../../src/providers"
-
-const model = XAI.provider.model("grok-4")
-
-LLM.request({ model, prompt: "Hello", providerOptions: { openai: { reasoningEffort: "high" } } })
-
-LLM.request({
-  model,
-  prompt: "Hello",
-  // @ts-expect-error xAI's OpenAI-compatible reasoning effort must be a string.
-  providerOptions: { openai: { reasoningEffort: true } },
-})

packages/ai/test/provider/anthropic-messages.test.ts

@@ -3,7 +3,6 @@ import { Effect } from "effect"
 import { HttpClientRequest } from "effect/unstable/http"
 import { CacheHint, LLM, LLMError, LLMRequest, Message, ToolCallPart, ToolDefinition, Usage } from "../../src"
 import { Auth, LLMClient } from "../../src/route"
-import { compileRequest } from "../../src/route/client"
 import * as AnthropicMessages from "../../src/protocols/anthropic-messages"
 import { continuationRequest, nativeAnthropicMessagesContinuation } from "../continuation-scenarios"
 import { it } from "../lib/effect"
@@ -45,7 +44,7 @@ const expectToolResult = (body: AnthropicMessages.AnthropicMessagesBody): Anthro
 describe("Anthropic Messages route", () => {
   it.effect("prepares Anthropic Messages target", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(request)
+      const prepared = yield* LLMClient.prepare(request)
 
       expect(prepared.body).toEqual({
         model: "claude-sonnet-4-5",
@@ -60,7 +59,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("lowers adaptive thinking settings with effort", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLMRequest.update(request, {
           providerOptions: {
             anthropic: { thinking: { type: "adaptive", display: "summarized" }, effort: "low" },
@@ -77,17 +76,17 @@ describe("Anthropic Messages route", () => {
 
   it.effect("normalizes enabled and disabled thinking settings", () =>
     Effect.gen(function* () {
-      const enabled = yield* compileRequest(
+      const enabled = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLMRequest.update(request, {
           providerOptions: { anthropic: { thinking: { type: "enabled", budgetTokens: 1_024 } } },
         }),
       )
-      const legacy = yield* compileRequest(
+      const legacy = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLMRequest.update(request, {
           providerOptions: { anthropic: { thinking: { type: "enabled", budget_tokens: 2_048 } } },
         }),
       )
-      const disabled = yield* compileRequest(
+      const disabled = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLMRequest.update(request, {
           providerOptions: { anthropic: { thinking: { type: "disabled" } } },
         }),
@@ -101,7 +100,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("rejects enabled thinking without a budget", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLMRequest.update(request, {
           providerOptions: { anthropic: { thinking: { type: "enabled" } } },
         }),
@@ -113,7 +112,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("lowers chronological system updates natively for Claude Opus 4.8 with cache hints", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLM.request({
           model: opus48,
           messages: [
@@ -138,7 +137,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("lowers chronological system updates to wrapped user text for unsupported Anthropic models", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLM.request({
           model,
           messages: [
@@ -165,7 +164,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("rejects non-text chronological system update content before send", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           model: opus48,
           messages: [
@@ -182,7 +181,7 @@ describe("Anthropic Messages route", () => {
   it.effect("falls back for unsupported native chronological system update placement", () =>
     Effect.gen(function* () {
       expect(
-        (yield* compileRequest(
+        (yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
           LLM.request({
             model: opus48,
             messages: [Message.assistant("Plain."), Message.system("After plain assistant.")],
@@ -197,11 +196,12 @@ describe("Anthropic Messages route", () => {
         },
       ])
       expect(
-        (yield* compileRequest(LLM.request({ model: opus48, messages: [Message.system("First.")], cache: "none" })))
-          .body.messages,
+        (yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
+          LLM.request({ model: opus48, messages: [Message.system("First.")], cache: "none" }),
+        )).body.messages,
       ).toEqual([{ role: "user", content: [{ type: "text", text: "<system-update>\nFirst.\n</system-update>" }] }])
       expect(
-        (yield* compileRequest(
+        (yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
           LLM.request({
             model: opus48,
             messages: [Message.user("Before."), Message.system("One."), Message.system("Two.")],
@@ -223,7 +223,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("rejects a system update between a local tool call and its result", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           model: opus48,
           messages: [
@@ -242,7 +242,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("prepares tool call and tool result messages", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLM.request({
           id: "req_tool_result",
           model,
@@ -273,7 +273,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("keeps tools and sends tool_choice none", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLM.request({
           id: "req_tool_choice_none",
           model,
@@ -303,7 +303,7 @@ describe("Anthropic Messages route", () => {
   // not JSON-stringified into `tool_result.content`.
   it.effect("lowers media tool-result content as structured blocks", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLM.request({
           id: "req_tool_result_image",
           model,
@@ -335,7 +335,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("lowers single-image tool-result content as a structured image block", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLM.request({
           id: "req_tool_result_image_only",
           model,
@@ -360,7 +360,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("rejects unsupported media in tool-result content with a clear error", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           id: "req_tool_result_unsupported_media",
           model,
@@ -384,7 +384,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("prepares the composed native continuation request", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         continuationRequest({
           id: "req_native_continuation_anthropic",
           model,
@@ -428,7 +428,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("lowers preserved Anthropic reasoning signature metadata", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           messages: [
@@ -447,7 +447,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("round-trips redacted thinking as redacted_thinking blocks", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           messages: [
@@ -628,7 +628,9 @@ describe("Anthropic Messages route", () => {
         { type: "reasoning", text: "", providerMetadata: { anthropic: { signature: "sig_1" } } },
       ])
 
-      const prepared = yield* compileRequest(LLM.request({ model, messages: [response.message], cache: "none" }))
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
+        LLM.request({ model, messages: [response.message], cache: "none" }),
+      )
       expect(prepared.body.messages).toEqual([
         { role: "assistant", content: [{ type: "thinking", thinking: "", signature: "sig_1" }] },
       ])
@@ -771,7 +773,7 @@ describe("Anthropic Messages route", () => {
           ),
         ),
       )
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
         LLM.request({
           model,
           messages: [
@@ -1131,7 +1133,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("round-trips provider-executed assistant content into server tool blocks", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_round_trip",
           model,
@@ -1182,7 +1184,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("rejects round-trip for unknown server tool names", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           id: "req_unknown_server_tool",
           model,
@@ -1259,7 +1261,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("maps ttlSeconds >= 3600 to cache_control ttl: '1h'", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           system: { type: "text", text: "system", cache: new CacheHint({ type: "ephemeral", ttlSeconds: 3600 }) },
@@ -1275,7 +1277,7 @@ describe("Anthropic Messages route", () => {
 
   it.effect("emits cache_control on tool definitions and tool-result blocks", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           tools: [
@@ -1316,7 +1318,7 @@ describe("Anthropic Messages route", () => {
   it.effect("drops cache_control breakpoints past the 4-per-request cap", () =>
     Effect.gen(function* () {
       const hint = new CacheHint({ type: "ephemeral" })
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           system: [
@@ -1342,7 +1344,7 @@ describe("Anthropic Messages route", () => {
   it.effect("spends breakpoint budget on tools before system before messages", () =>
     Effect.gen(function* () {
       const hint = new CacheHint({ type: "ephemeral" })
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           tools: [

packages/ai/test/provider/bedrock-converse.test.ts

@@ -13,7 +13,6 @@ import {
   ToolDefinition,
 } from "../../src"
 import { LLMClient } from "../../src/route"
-import { compileRequest } from "../../src/route/client"
 import { AmazonBedrock } from "../../src/providers"
 import * as BedrockConverse from "../../src/protocols/bedrock-converse"
 import { it } from "../lib/effect"
@@ -102,7 +101,7 @@ const baseRequest = LLM.request({
 describe("Bedrock Converse route", () => {
   it.effect("prepares Converse target with system, inference config, and messages", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(baseRequest)
+      const prepared = yield* LLMClient.prepare(baseRequest)
 
       expect(prepared.body).toEqual({
         modelId: "anthropic.claude-3-5-sonnet-20240620-v1:0",
@@ -115,7 +114,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("passes topK through additionalModelRequestFields as top_k", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<BedrockConverse.BedrockConverseBody>(
         LLMRequest.update(baseRequest, {
           generation: GenerationOptions.make({ maxTokens: 64, temperature: 0, topK: 40 }),
         }),
@@ -130,14 +129,14 @@ describe("Bedrock Converse route", () => {
 
   it.effect("omits additionalModelRequestFields when topK is unset", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(baseRequest)
+      const prepared = yield* LLMClient.prepare<BedrockConverse.BedrockConverseBody>(baseRequest)
       expect(prepared.body.additionalModelRequestFields).toBeUndefined()
     }),
   )
 
   it.effect("lowers chronological system updates to wrapped user text in order", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<BedrockConverse.BedrockConverseBody>(
         LLM.request({
           model,
           messages: [Message.user("Before."), Message.system("Update."), Message.assistant("After.")],
@@ -154,7 +153,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("prepares tool config with toolSpec and toolChoice", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLMRequest.update(baseRequest, {
           tools: [
             ToolDefinition.make({
@@ -188,7 +187,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("keeps tools and omits the unsupported choice when tool choice is none", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLMRequest.update(baseRequest, {
           tools: [
             ToolDefinition.make({
@@ -218,7 +217,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("lowers assistant tool-call + tool-result message history", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_history",
           model,
@@ -257,7 +256,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("lowers image content in tool-result messages", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_tool_image",
           model,
@@ -492,7 +491,7 @@ describe("Bedrock Converse route", () => {
         providerMetadata: { bedrock: { signature: "sig_1" } },
       })
 
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<BedrockConverse.BedrockConverseBody>(
         LLM.request({
           model,
           messages: [
@@ -547,7 +546,9 @@ describe("Bedrock Converse route", () => {
         },
       ])
 
-      const prepared = yield* compileRequest(LLM.request({ model, messages: [response.message], cache: "none" }))
+      const prepared = yield* LLMClient.prepare<BedrockConverse.BedrockConverseBody>(
+        LLM.request({ model, messages: [response.message], cache: "none" }),
+      )
       expect(prepared.body.messages).toEqual([
         {
           role: "assistant",
@@ -638,7 +639,7 @@ describe("Bedrock Converse route", () => {
         text: "",
         providerMetadata: { bedrock: { redactedData } },
       })
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<BedrockConverse.BedrockConverseBody>(
         LLM.request({
           model,
           messages: [
@@ -753,7 +754,7 @@ describe("Bedrock Converse route", () => {
           secretAccessKey: "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY",
         },
       }).model("anthropic.claude-3-5-sonnet-20240620-v1:0")
-      const prepared = yield* compileRequest(LLMRequest.update(baseRequest, { model: signed }))
+      const prepared = yield* LLMClient.prepare(LLMRequest.update(baseRequest, { model: signed }))
 
       expect(prepared.route).toBe("bedrock-converse")
       expect(prepared.model).toBe(signed)
@@ -763,7 +764,7 @@ describe("Bedrock Converse route", () => {
   it.effect("emits cachePoint markers after system, user-text, and assistant-text with cache hints", () =>
     Effect.gen(function* () {
       const cache = new CacheHint({ type: "ephemeral" })
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_cache",
           model,
@@ -795,7 +796,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("does not emit cachePoint when no cache hint is set", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(baseRequest)
+      const prepared = yield* LLMClient.prepare(baseRequest)
       expect(prepared.body).toMatchObject({
         system: [{ text: "You are concise." }],
         messages: [{ role: "user", content: [{ text: "Say hello." }] }],
@@ -805,7 +806,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("lowers image media into Bedrock image blocks", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_image",
           model,
@@ -842,7 +843,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("base64-encodes Uint8Array image bytes", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_image_bytes",
           model,
@@ -864,7 +865,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("lowers document media into Bedrock document blocks with format and name", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_doc",
           model,
@@ -896,7 +897,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("requires names for document media", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           model,
           messages: [Message.user({ type: "media", mediaType: "application/pdf", data: "UERGREFUQQ==" })],
@@ -909,7 +910,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("passes named document-only messages through for provider validation", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<BedrockConverse.BedrockConverseBody>(
         LLM.request({
           model,
           cache: "none",
@@ -935,7 +936,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("lowers document media in tool results", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<BedrockConverse.BedrockConverseBody>(
         LLM.request({
           model,
           cache: "none",
@@ -987,7 +988,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("rejects unsupported image media types", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           id: "req_bad_image",
           model,
@@ -1001,7 +1002,7 @@ describe("Bedrock Converse route", () => {
 
   it.effect("rejects unsupported document media types", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           id: "req_bad_doc",
           model,
@@ -1016,7 +1017,7 @@ describe("Bedrock Converse route", () => {
   it.effect("maps ttlSeconds >= 3600 to cachePoint ttl: '1h'", () =>
     Effect.gen(function* () {
       const cache = new CacheHint({ type: "ephemeral", ttlSeconds: 3600 })
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           system: [{ type: "text", text: "system", cache }],
@@ -1033,7 +1034,7 @@ describe("Bedrock Converse route", () => {
   it.effect("appends cachePoint after marked tool definitions and tool-result blocks", () =>
     Effect.gen(function* () {
       const cache = new CacheHint({ type: "ephemeral" })
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           tools: [{ name: "lookup", description: "lookup", inputSchema: { type: "object", properties: {} }, cache }],
@@ -1065,7 +1066,7 @@ describe("Bedrock Converse route", () => {
   it.effect("drops cachePoint markers past the 4-per-request cap", () =>
     Effect.gen(function* () {
       const cache = new CacheHint({ type: "ephemeral" })
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           system: [

packages/ai/test/provider/cloudflare.test.ts

@@ -3,7 +3,7 @@ import { ConfigProvider, Effect, Schema } from "effect"
 import { HttpClientRequest } from "effect/unstable/http"
 import { LLM, LLMEvent } from "../../src"
 import { CloudflareAIGateway, CloudflareWorkersAI } from "../../src/providers/cloudflare"
-import { compileRequest } from "../../src/route/client"
+import { LLMClient } from "../../src/route"
 import { it } from "../lib/effect"
 import { dynamicResponse } from "../lib/http"
 import { sseEvents } from "../lib/sse"
@@ -34,7 +34,7 @@ describe("Cloudflare", () => {
       })
       expect(model.route.endpoint.baseURL).toBe("https://gateway.ai.cloudflare.com/v1/test-account/test-gateway/compat")
 
-      const prepared = yield* compileRequest(LLM.request({ model, prompt: "Say hello." }))
+      const prepared = yield* LLMClient.prepare(LLM.request({ model, prompt: "Say hello." }))
 
       expect(prepared.route).toBe("cloudflare-ai-gateway")
       expect(prepared.body).toMatchObject({
@@ -129,7 +129,7 @@ describe("Cloudflare", () => {
         openai: { reasoningField: "reasoning", reasoningDetails: merged },
       })
 
-      const replay = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      const replay = yield* LLMClient.prepare(LLM.request({ model, messages: [response.message] }))
       expect(replay.body.messages).toEqual([
         { role: "assistant", content: "Hello", reasoning: "Thinking", reasoning_details: merged },
       ])
@@ -180,7 +180,7 @@ describe("Cloudflare", () => {
 
   it.effect("allows a fully configured baseURL override", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: CloudflareAIGateway.configure({
             baseURL: "https://gateway.proxy.test/v1/custom/compat",
@@ -208,7 +208,7 @@ describe("Cloudflare", () => {
       })
       expect(model.route.endpoint.baseURL).toBe("https://api.cloudflare.com/client/v4/accounts/test-account/ai/v1")
 
-      const prepared = yield* compileRequest(LLM.request({ model, prompt: "Say hello." }))
+      const prepared = yield* LLMClient.prepare(LLM.request({ model, prompt: "Say hello." }))
 
       expect(prepared.route).toBe("cloudflare-workers-ai")
       expect(prepared.body).toMatchObject({

packages/ai/test/provider/gemini.test.ts

@@ -2,7 +2,6 @@ import { describe, expect } from "bun:test"
 import { Effect } from "effect"
 import { LLM, LLMError, LLMRequest, Message, ToolCallPart, ToolDefinition, Usage } from "../../src"
 import { Auth, LLMClient } from "../../src/route"
-import { compileRequest } from "../../src/route/client"
 import * as Gemini from "../../src/protocols/gemini"
 import { ProviderShared } from "../../src/protocols/shared"
 import { it } from "../lib/effect"
@@ -27,7 +26,7 @@ const request = LLM.request({
 describe("Gemini route", () => {
   it.effect("prepares Gemini target", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(request)
+      const prepared = yield* LLMClient.prepare(request)
 
       expect(prepared.body).toEqual({
         contents: [{ role: "user", parts: [{ text: "Say hello." }] }],
@@ -39,12 +38,12 @@ describe("Gemini route", () => {
 
   it.effect("normalizes Gemini thinking options", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<Gemini.GeminiBody>(
         LLMRequest.update(request, {
           providerOptions: { gemini: { thinkingConfig: { thinkingBudget: 0, includeThoughts: false } } },
         }),
       )
-      const filtered = yield* compileRequest(
+      const filtered = yield* LLMClient.prepare<Gemini.GeminiBody>(
         LLMRequest.update(request, {
           providerOptions: { gemini: { thinkingConfig: { thinkingBudget: "invalid", includeThoughts: false } } },
         }),
@@ -60,7 +59,7 @@ describe("Gemini route", () => {
 
   it.effect("lowers chronological system updates to wrapped user text in order", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<Gemini.GeminiBody>(
         LLM.request({
           model,
           messages: [Message.user("Before."), Message.system("Update."), Message.assistant("After.")],
@@ -76,7 +75,7 @@ describe("Gemini route", () => {
 
   it.effect("prepares multimodal user input and tool history", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_tool_result",
           model,
@@ -144,7 +143,7 @@ describe("Gemini route", () => {
 
   it.effect("continues media tool results as inline model input without base64 text", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<Gemini.GeminiBody>(
         LLM.request({
           model,
           messages: [
@@ -189,7 +188,7 @@ describe("Gemini route", () => {
 
   it.effect("strips matching data URLs to raw base64 inlineData", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<Gemini.GeminiBody>(
         LLM.request({
           model,
           messages: [
@@ -230,7 +229,7 @@ describe("Gemini route", () => {
   ] as const)
     it.effect(`rejects ${name}`, () =>
       Effect.gen(function* () {
-        const error = yield* compileRequest(
+        const error = yield* LLMClient.prepare(
           LLM.request({ model, messages: [Message.user({ type: "media", ...media })] }),
         ).pipe(Effect.flip)
         expect(error.message).toMatch(/does not support|does not match|valid base64/)
@@ -239,7 +238,7 @@ describe("Gemini route", () => {
 
   it.effect("rejects oversized image input", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           model,
           messages: [
@@ -257,7 +256,7 @@ describe("Gemini route", () => {
 
   it.effect("keeps tools and sends function calling mode NONE", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_tool_choice_none",
           model,
@@ -277,7 +276,7 @@ describe("Gemini route", () => {
 
   it.effect("sanitizes integer enums, dangling required, untyped arrays, and scalar object keys", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_schema_patch",
           model,
@@ -458,7 +457,7 @@ describe("Gemini route", () => {
         response.events.findIndex((event) => event.type === "tool-call"),
       )
 
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<Gemini.GeminiBody>(
         LLM.request({
           model,
           messages: [
@@ -692,7 +691,7 @@ describe("Gemini route", () => {
 
   it.effect("rejects unsupported assistant media content", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           id: "req_media",
           model,

packages/ai/test/provider/google-vertex.test.ts

@@ -4,7 +4,6 @@ import { HttpClientRequest } from "effect/unstable/http"
 import { LLM } from "../../src"
 import { GoogleVertex, GoogleVertexChat, GoogleVertexMessages, GoogleVertexResponses } from "../../src/providers"
 import { LLMClient } from "../../src/route"
-import { compileRequest } from "../../src/route/client"
 import { it } from "../lib/effect"
 import { dynamicResponse } from "../lib/http"
 import { deltaChunk, finishChunk } from "../lib/openai-chunks"
@@ -183,7 +182,7 @@ describe("Google Vertex providers", () => {
 
   it.effect("protects the Vertex Messages API version from body overlays", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           model: GoogleVertexMessages.configure({
             accessToken: "vertex-token",

packages/ai/test/provider/openai-chat-reasoning.recorded.test.ts

@@ -5,7 +5,6 @@ import { OpenAIChat } from "../../src/protocols/openai-chat"
 import * as OpenAICompatible from "../../src/providers/openai-compatible"
 import * as OpenRouter from "../../src/providers/openrouter"
 import { LLMClient } from "../../src/route"
-import { compileRequest } from "../../src/route/client"
 import { recordedTests } from "../recorded-test"
 import { expectWeatherToolLoop, goldenWeatherToolLoopRequest, runWeatherToolLoop } from "../recorded-scenarios"
 
@@ -85,7 +84,9 @@ for (const item of cases) {
             ),
           ).toBe(true)
 
-          const replay = yield* compileRequest(LLM.request({ model: item.model, messages: [response.message] }))
+          const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
+            LLM.request({ model: item.model, messages: [response.message] }),
+          )
           expect(replay.body.messages).toMatchObject([
             { role: "assistant", content: response.text, reasoning: response.reasoning },
           ])

packages/ai/test/provider/openai-chat.test.ts

@@ -18,7 +18,6 @@ import * as OpenAI from "../../src/providers/openai"
 import * as OpenAIChat from "../../src/protocols/openai-chat"
 import { ProviderShared } from "../../src/protocols/shared"
 import { Auth, LLMClient } from "../../src/route"
-import { compileRequest } from "../../src/route/client"
 import { it } from "../lib/effect"
 import { dynamicResponse, fixedResponse, truncatedStream } from "../lib/http"
 import { deltaChunk, usageChunk } from "../lib/openai-chunks"
@@ -43,7 +42,11 @@ const request = LLM.request({
 describe("OpenAI Chat route", () => {
   it.effect("prepares OpenAI Chat payload", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(request)
+      // Pass the OpenAIChat payload type so `prepared.body` is statically
+      // typed to the route's native shape — the assertions below read field
+      // names without `unknown` casts.
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(request)
+      const _typed: { readonly model: string; readonly stream: true } = prepared.body
 
       expect(prepared.body).toEqual({
         model: "gpt-4o-mini",
@@ -61,7 +64,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("lowers chronological system updates to escaped user wrappers in order", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           messages: [
@@ -84,7 +87,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("replays canonical reasoning as OpenAI-compatible reasoning_content", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           messages: [
@@ -102,7 +105,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("writes reasoning to a configured custom field on every assistant message", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model: Model.update(model, { compatibility: { reasoningField: "vendor_reasoning" } }),
           messages: [
@@ -128,7 +131,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("rejects reasoning fields that conflict with assistant message fields", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           model: Model.update(model, { compatibility: { reasoningField: "content" } }),
           messages: [Message.assistant([{ type: "reasoning", text: "thinking" }])],
@@ -141,7 +144,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("maps OpenAI provider options to Chat options", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model: OpenAI.configure({ baseURL: "https://api.openai.test/v1/", apiKey: "test" }).chat("gpt-4o-mini"),
           prompt: "think",
@@ -156,7 +159,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("passes through custom OpenAI-compatible reasoning effort strings", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           prompt: "think",
@@ -250,7 +253,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("prepares assistant tool-call and tool-result messages", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_tool_result",
           model,
@@ -288,7 +291,7 @@ describe("OpenAI Chat route", () => {
   it.effect("preserves structured tool errors for the model", () =>
     Effect.gen(function* () {
       const error = { error: { type: "unknown", message: "Tool execution interrupted" } }
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           messages: [
@@ -308,7 +311,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("continues image tool results as vision input without base64 text", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           messages: [
@@ -352,7 +355,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("orders parallel tool responses before one aggregated vision message", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           messages: [
@@ -402,7 +405,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("aggregates consecutive tool images with a following system update", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           messages: [
@@ -443,7 +446,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("appends system updates without replacing multipart user content", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           messages: [
@@ -471,7 +474,7 @@ describe("OpenAI Chat route", () => {
   ] as const)
     it.effect(`rejects ${name}`, () =>
       Effect.gen(function* () {
-        const error = yield* compileRequest(
+        const error = yield* LLMClient.prepare(
           LLM.request({ model, messages: [Message.user({ type: "media", ...media })] }),
         ).pipe(Effect.flip)
         expect(error.message).toMatch(/does not support|does not match|valid base64/)
@@ -480,7 +483,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("rejects oversized image input", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           model,
           messages: [
@@ -498,7 +501,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("prepares raw and data URL image media as vision input", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           id: "req_media",
           model,
@@ -525,7 +528,7 @@ describe("OpenAI Chat route", () => {
 
   it.effect("lowers reasoning-only assistant history", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           id: "req_reasoning",
           model,
@@ -616,7 +619,9 @@ describe("OpenAI Chat route", () => {
           openai: { reasoningField: field },
         })
 
-        const replay = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+        const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
+          LLM.request({ model, messages: [response.message] }),
+        )
         expect(replay.body.messages).toEqual([{ role: "assistant", content: "Hello", [field]: "thinking" }])
       }
     }),
@@ -642,7 +647,9 @@ describe("OpenAI Chat route", () => {
         openai: { reasoningField: "vendor_reasoning" },
       })
 
-      const replay = yield* compileRequest(LLM.request({ model: custom, messages: [response.message] }))
+      const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
+        LLM.request({ model: custom, messages: [response.message] }),
+      )
       expect(replay.body.messages).toEqual([{ role: "assistant", content: "Hello", vendor_reasoning: "thinking" }])
     }),
   )
@@ -685,7 +692,9 @@ describe("OpenAI Chat route", () => {
         openai: { reasoningField: "reasoning", reasoningDetails: details },
       })
 
-      const replay = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
+        LLM.request({ model, messages: [response.message] }),
+      )
       expect(replay.body.messages).toEqual([
         {
           role: "assistant",
@@ -728,7 +737,9 @@ describe("OpenAI Chat route", () => {
         openai: { reasoningDetails: details },
       })
 
-      const replay = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
+        LLM.request({ model, messages: [response.message] }),
+      )
       expect(replay.body.messages).toEqual([{ role: "assistant", content: "Hello", reasoning_details: details }])
     }),
   )
@@ -753,7 +764,9 @@ describe("OpenAI Chat route", () => {
         openai: { reasoningField: "reasoning", reasoningDetails: details },
       })
 
-      const replay = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
+        LLM.request({ model, messages: [response.message] }),
+      )
       expect(replay.body.messages).toEqual([
         { role: "assistant", content: "Hello", reasoning: "thinking", reasoning_details: details },
       ])
@@ -826,7 +839,9 @@ describe("OpenAI Chat route", () => {
         openai: { reasoningDetails: [] },
       })
 
-      const replay = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
+        LLM.request({ model, messages: [response.message] }),
+      )
       expect(replay.body.messages).toEqual([{ role: "assistant", content: "Hello", reasoning_details: [] }])
     }),
   )
@@ -874,7 +889,9 @@ describe("OpenAI Chat route", () => {
         response.events.findIndex(LLMEvent.is.textStart),
       )
 
-      const replay = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
+        LLM.request({ model, messages: [response.message] }),
+      )
       expect(replay.body.messages).toEqual([
         { role: "assistant", content: "Hello", reasoning: "thinking", reasoning_details: merged },
       ])
@@ -901,7 +918,9 @@ describe("OpenAI Chat route", () => {
       expect(response.events.filter(LLMEvent.is.reasoningStart)).toHaveLength(1)
       expect(response.events.filter(LLMEvent.is.reasoningEnd)).toHaveLength(1)
 
-      const replay = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
+        LLM.request({ model, messages: [response.message] }),
+      )
       expect(replay.body.messages).toEqual([{ role: "assistant", content: null, reasoning_details: details }])
     }),
   )
@@ -931,7 +950,7 @@ describe("OpenAI Chat route", () => {
     Effect.gen(function* () {
       const first = { type: "reasoning.text", text: "first", signature: "signed-0", index: 0 }
       const second = { type: "reasoning.text", text: "second", signature: "signed-1", index: 1 }
-      const replay = yield* compileRequest(
+      const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           messages: [
@@ -960,7 +979,7 @@ describe("OpenAI Chat route", () => {
   it.effect("retains scalar replay for mixed structured reasoning parts", () =>
     Effect.gen(function* () {
       const detail = { type: "reasoning.encrypted", data: "opaque", index: 0 }
-      const replay = yield* compileRequest(
+      const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           messages: [
@@ -985,7 +1004,7 @@ describe("OpenAI Chat route", () => {
   it.effect("replays native scalar reasoning alongside native details", () =>
     Effect.gen(function* () {
       const details = [{ type: "reasoning.encrypted", data: "opaque", index: 0 }]
-      const replay = yield* compileRequest(
+      const replay = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           messages: [

packages/ai/test/provider/openai-compatible-chat.test.ts

@@ -3,7 +3,6 @@ import { Effect, Schema } from "effect"
 import { HttpClientRequest } from "effect/unstable/http"
 import { LLM, LLMRequest, Message, ToolCallPart, ToolChoice, ToolDefinition } from "../../src"
 import { Auth, LLMClient } from "../../src/route"
-import { compileRequest } from "../../src/route/client"
 import * as OpenAICompatible from "../../src/providers/openai-compatible"
 import * as OpenAICompatibleChat from "../../src/protocols/openai-compatible-chat"
 import { it } from "../lib/effect"
@@ -53,7 +52,7 @@ const providerFamilies = [
 describe("OpenAI-compatible Chat route", () => {
   it.effect("prepares generic Chat target", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLMRequest.update(request, {
           tools: [ToolDefinition.make({ name: "lookup", description: "Lookup data", inputSchema: { type: "object" } })],
           toolChoice: ToolChoice.make({ type: "required" }),
@@ -128,7 +127,7 @@ describe("OpenAI-compatible Chat route", () => {
 
   it.effect("matches AI SDK compatible basic request body fixture", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(request)
+      const prepared = yield* LLMClient.prepare(request)
 
       expect(prepared.body).toEqual({
         model: "deepseek-chat",
@@ -146,7 +145,7 @@ describe("OpenAI-compatible Chat route", () => {
 
   it.effect("matches AI SDK compatible tool request body fixture", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_tool_parity",
           model,

packages/ai/test/provider/openai-compatible-responses.test.ts

@@ -7,7 +7,6 @@ import { OpenResponses } from "../../src/protocols/open-responses"
 import { OpenAICompatibleResponses } from "../../src/protocols/openai-compatible-responses"
 import { OpenAIResponses } from "../../src/protocols/openai-responses"
 import { LLMClient } from "../../src/route"
-import { compileRequest } from "../../src/route/client"
 import { it } from "../lib/effect"
 import { fixedResponse } from "../lib/http"
 import { sseEvents } from "../lib/sse"
@@ -24,7 +23,7 @@ describe("Open Responses-compatible route", () => {
         baseURL: "https://responses.example.test/v1",
         provider: "example",
       }).model("example-model")
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           system: "You are concise.",
@@ -62,7 +61,7 @@ describe("Open Responses-compatible route", () => {
         apiKey: "test-key",
         baseURL: "https://responses.example.test/v1",
       }).model("example-model")
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({ model, prompt: "Draw.", tools: [OpenAI.imageGeneration()] }),
       ).pipe(Effect.flip)
 
@@ -77,7 +76,7 @@ describe("Open Responses-compatible route", () => {
         apiKey: "test-key",
         baseURL: "https://responses.example.test/v1",
       }).model("example-model")
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model,
           messages: [
@@ -103,7 +102,7 @@ describe("Open Responses-compatible route", () => {
         baseURL: "https://responses.example.test/v1",
         providerOptions: { openresponses: { reasoningEffort: "low", store: true } },
       }).model("example-model")
-      const prepared = yield* compileRequest(LLM.request({ model, prompt: "Think." }))
+      const prepared = yield* LLMClient.prepare(LLM.request({ model, prompt: "Think." }))
 
       expect(prepared.body).toMatchObject({
         reasoning: { effort: "low" },

packages/ai/test/provider/openai-responses.test.ts

@@ -14,7 +14,6 @@ import {
   Usage,
 } from "../../src"
 import { Auth, LLMClient, RequestExecutor, WebSocketExecutor } from "../../src/route"
-import { compileRequest } from "../../src/route/client"
 import * as Azure from "../../src/providers/azure"
 import * as OpenAI from "../../src/providers/openai"
 import * as XAI from "../../src/providers/xai"
@@ -57,7 +56,7 @@ const expectToolOutput = (body: OpenAIResponses.OpenAIResponsesBody): OpenAITool
 describe("OpenAI Responses route", () => {
   it.effect("prepares OpenAI Responses target", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(request)
+      const prepared = yield* LLMClient.prepare(request)
 
       expect(prepared.body).toEqual({
         model: "gpt-4.1-mini",
@@ -75,7 +74,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("lowers the hosted OpenAI image generation tool", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model,
           prompt: "Show me a rooftop garden.",
@@ -93,7 +92,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("rejects invalid hosted image generation options locally", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           model,
           prompt: "Show me a rooftop garden.",
@@ -110,7 +109,7 @@ describe("OpenAI Responses route", () => {
     Effect.gen(function* () {
       const input = LLMRequest.update(request, { providerOptions: { openai: { serviceTier: "priority" } } })
       expect(input.providerOptions).toEqual({ openai: { serviceTier: "priority" } })
-      const prepared = yield* compileRequest(input)
+      const prepared = yield* LLMClient.prepare(input)
 
       expect(prepared.body).toMatchObject({ service_tier: "priority" })
       expect(prepared.body).not.toHaveProperty("serviceTier")
@@ -119,7 +118,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("passes through custom OpenAI reasoning effort strings", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLMRequest.update(request, { providerOptions: { openai: { reasoningEffort: "experimental" } } }),
       )
 
@@ -129,7 +128,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("omits unsupported semantic service tiers", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLMRequest.update(request, { providerOptions: { openai: { serviceTier: "unsupported" } } }),
       )
 
@@ -139,7 +138,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("flattens top-level object unions in function schemas", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLMRequest.update(request, {
           tools: [
             ToolDefinition.make({
@@ -192,7 +191,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("lowers chronological system updates to escaped user wrappers in order", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model,
           messages: [
@@ -218,7 +217,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("prepares OpenAI Responses WebSocket target", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLMRequest.update(request, {
           model: OpenAIResponses.webSocketRoute
             .with({ endpoint: { baseURL: "https://api.openai.test/v1/" }, auth: Auth.bearer("test") })
@@ -396,7 +395,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("prepares function call and function output input items", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_tool_result",
           model,
@@ -433,7 +432,7 @@ describe("OpenAI Responses route", () => {
         content: [],
         structured: {},
       }
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model,
           messages: [
@@ -454,7 +453,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("keeps primitive tool errors as plain text", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model,
           messages: [
@@ -470,7 +469,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("keeps non-JSON tool errors as plain text", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model,
           messages: [
@@ -488,7 +487,7 @@ describe("OpenAI Responses route", () => {
   // image data is not JSON-stringified into `function_call_output.output`.
   it.effect("lowers image tool-result content as structured input_image items", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           id: "req_tool_result_image",
           model,
@@ -517,7 +516,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("lowers single-image tool-result content as structured input_image array", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           id: "req_tool_result_image_only",
           model,
@@ -541,7 +540,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("lowers PDF tool-result content as structured input_file array", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           id: "req_tool_result_pdf",
           model,
@@ -576,7 +575,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("uses xAI inline file encoding for PDF tool results", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model: xaiModel,
           messages: [
@@ -611,7 +610,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("rejects unsupported media in tool-result content with a clear error", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           id: "req_tool_result_unsupported_media",
           model,
@@ -634,7 +633,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("prepares the composed native continuation request", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         continuationRequest({
           id: "req_native_continuation_openai",
           model,
@@ -676,7 +675,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("maps OpenAI provider options to Responses options", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model: OpenAI.configure({ baseURL: "https://api.openai.test/v1/", apiKey: "test" }).model("gpt-5.2"),
           prompt: "think",
@@ -701,7 +700,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("accepts the full ResponseIncludable union", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model,
           prompt: "hi",
@@ -723,7 +722,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("filters unknown includable values out of the include array", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model,
           prompt: "hi",
@@ -740,7 +739,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("treats an explicit empty include as no include at all", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({ model, prompt: "hi", providerOptions: { openai: { include: [] } } }),
       )
 
@@ -750,7 +749,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("treats an all-invalid include as no include at all", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({ model, prompt: "hi", providerOptions: { openai: { include: ["bogus.thing"] } } }),
       )
 
@@ -760,7 +759,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("omits include when no include is set", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({ model, prompt: "hi", providerOptions: { openai: { store: false } } }),
       )
 
@@ -774,7 +773,7 @@ describe("OpenAI Responses route", () => {
       // reasoningSummary: "auto" by default. Without `include`, a follow-up
       // turn cannot replay reasoning state, so the facade also opts into
       // `reasoning.encrypted_content` automatically.
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model: OpenAI.configure({ baseURL: "https://api.openai.test/v1/", apiKey: "test" }).responses("gpt-5.2"),
           prompt: "hi",
@@ -789,7 +788,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("lets callers opt out of the GPT-5 default include", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model: OpenAI.configure({ baseURL: "https://api.openai.test/v1/", apiKey: "test" }).responses("gpt-5.2"),
           prompt: "hi",
@@ -803,7 +802,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("request OpenAI provider options override route defaults", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model: OpenAI.configure({
             baseURL: "https://api.openai.test/v1/",
@@ -935,7 +934,9 @@ describe("OpenAI Responses route", () => {
         },
       ])
 
-      const prepared = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
+        LLM.request({ model, messages: [response.message] }),
+      )
       expect(prepared.body.input).toEqual([
         {
           role: "assistant",
@@ -1269,7 +1270,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("preserves assistant content order around reasoning items", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           id: "req_reasoning_order",
           model,
@@ -1307,7 +1308,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("references stored reasoning items by id", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model,
           messages: [
@@ -1329,7 +1330,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("references stored provider-executed hosted tool results by id", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model,
           messages: [
@@ -1366,7 +1367,7 @@ describe("OpenAI Responses route", () => {
   it.effect("continues stateless hosted image generation with the generated image", () =>
     Effect.gen(function* () {
       const imageTool = OpenAI.imageGeneration({ action: "edit" })
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model,
           messages: [
@@ -1407,7 +1408,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("joins streamed summary blocks into one continuation reasoning item", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           id: "req_multi_summary_continuation",
           model,
@@ -1444,7 +1445,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("skips non-persisted reasoning ids without encrypted state", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           id: "req_reasoning_without_encrypted_state",
           model,
@@ -1761,7 +1762,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("lowers user image and PDF content", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           id: "req_media",
           model,
@@ -1792,7 +1793,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("uses xAI inline file encoding for user PDFs", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
         LLM.request({
           model: xaiModel,
           messages: [
@@ -1824,7 +1825,7 @@ describe("OpenAI Responses route", () => {
 
   it.effect("rejects unsupported user media content", () =>
     Effect.gen(function* () {
-      const error = yield* compileRequest(
+      const error = yield* LLMClient.prepare(
         LLM.request({
           id: "req_media",
           model,

packages/ai/test/provider/openrouter.test.ts

@@ -2,7 +2,6 @@ import { describe, expect } from "bun:test"
 import { Effect } from "effect"
 import { LLM, Message } from "../../src"
 import { LLMClient } from "../../src/route"
-import { compileRequest } from "../../src/route/client"
 import * as OpenRouter from "../../src/providers/openrouter"
 import { it } from "../lib/effect"
 import { fixedResponse } from "../lib/http"
@@ -20,7 +19,7 @@ describe("OpenRouter", () => {
       })
       expect(model.route.endpoint.baseURL).toBe("https://openrouter.ai/api/v1")
 
-      const prepared = yield* compileRequest(LLM.request({ model, prompt: "Say hello." }))
+      const prepared = yield* LLMClient.prepare(LLM.request({ model, prompt: "Say hello." }))
 
       expect(prepared.route).toBe("openrouter")
       expect(prepared.body).toMatchObject({
@@ -33,7 +32,7 @@ describe("OpenRouter", () => {
 
   it.effect("applies OpenRouter payload options from the model helper", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare(
         LLM.request({
           model: OpenRouter.configure({
             apiKey: "test-key",
@@ -101,7 +100,7 @@ describe("OpenRouter", () => {
         { type: "reasoning.text", signature: "signed", format: "anthropic-claude-v1", index: 0 },
         { type: "reasoning.encrypted", data: "opaque", format: "openai-responses-v1", index: 1 },
       ]
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenRouter.OpenRouterBody>(
         LLM.request({
           model: OpenRouter.configure({ apiKey: "test-key" }).model("anthropic/claude-sonnet-4.6"),
           messages: [
@@ -134,7 +133,7 @@ describe("OpenRouter", () => {
         { type: "reasoning.encrypted", id: "state", data: "opaque" },
         { type: "reasoning.encrypted", id: "state", data: "opaque" },
       ]
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenRouter.OpenRouterBody>(
         LLM.request({
           model: OpenRouter.configure({ apiKey: "test-key" }).model("anthropic/claude-sonnet-4.6"),
           messages: [
@@ -159,7 +158,7 @@ describe("OpenRouter", () => {
         { type: "reasoning.text", id: "first", index: 0, text: "A", opaque: "first" },
         { type: "reasoning.text", id: "second", index: 1, text: "B", opaque: "second" },
       ]
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenRouter.OpenRouterBody>(
         LLM.request({
           model: OpenRouter.configure({ apiKey: "test-key" }).model("anthropic/claude-sonnet-4.6"),
           messages: [
@@ -180,7 +179,7 @@ describe("OpenRouter", () => {
 
   it.effect("omits scalar reasoning without continuation details", () =>
     Effect.gen(function* () {
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenRouter.OpenRouterBody>(
         LLM.request({
           model: OpenRouter.configure({ apiKey: "test-key" }).model("anthropic/claude-sonnet-4.6"),
           messages: [Message.assistant({ type: "reasoning", text: "Thinking" })],

packages/ai/test/tool-schema-projection.test.ts

@@ -3,8 +3,7 @@ import { Effect } from "effect"
 import { LLM } from "../src"
 import { OpenAIChat } from "../src/protocols"
 import { ToolSchemaProjection } from "../src/protocols/utils/tool-schema"
-import { Auth } from "../src/route"
-import { compileRequest } from "../src/route/client"
+import { Auth, LLMClient } from "../src/route"
 import { it } from "./lib/effect"
 
 describe("tool schema projections", () => {
@@ -80,7 +79,7 @@ describe("tool schema projections", () => {
       const model = OpenAIChat.route
         .with({ endpoint: { baseURL: "https://api.openai.test/v1/" }, auth: Auth.bearer("test") })
         .model({ id: "kimi-k2", compatibility: { toolSchema: "moonshot" } })
-      const prepared = yield* compileRequest(
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
         LLM.request({
           model,
           prompt: "Use the tool.",

packages/app/src/components/dialog-fork.tsx

@@ -69,7 +69,7 @@ export const DialogFork: Component = () => {
     const dir = base64Encode(sdk().directory)
 
     sdk()
-      .api.session.fork({ sessionID, boundary: { type: "before", messageID: item.id } })
+      .api.session.fork({ sessionID, messageID: item.id })
       .then((forked) => {
         dialog.close()
         prompt.set(restored, undefined, { dir, id: forked.id })

packages/app/src/pages/session.tsx

@@ -57,7 +57,7 @@ import { ServerConnection, serverName, useServer } from "@/context/server"
 import { useSettings } from "@/context/settings"
 import { useSync } from "@/context/sync"
 import { useTabs } from "@/context/tabs"
-import { TerminalProvider, useTerminal } from "@/context/terminal"
+import { TerminalProvider } from "@/context/terminal"
 import { PromptInput } from "@/components/prompt-input"
 import { PromptInputV2Composer, usePromptInputV2Controller } from "@/components/prompt-input-v2"
 import { useSettingsCommand } from "@/components/settings-dialog"
@@ -70,11 +70,11 @@ import {
   createSessionComposerRegionController,
   SessionComposerRegion,
 } from "@/pages/session/composer"
-import { createOpenReviewFile, createSessionTabs, createSizing, shouldShowFileTree } from "@/pages/session/helpers"
+import { createOpenReviewFile, createSizing, shouldShowFileTree } from "@/pages/session/helpers"
 import { MessageTimeline } from "@/pages/session/timeline/message-timeline"
 import { createTimelineModel } from "@/pages/session/timeline/model"
 import { type DiffStyle, SessionReviewTab, type SessionReviewTabProps } from "@/pages/session/review-tab"
-import { useSessionLayout } from "@/pages/session/session-layout"
+import { createSessionController } from "@/pages/session/session-controller"
 import { restorePromptModel, syncPromptModel, syncSessionModel } from "@/pages/session/session-model-helpers"
 import {
   clampSessionPanelWidth,
@@ -101,7 +101,6 @@ import { extractPromptFromParts } from "@/utils/prompt"
 import { formatServerError, isLocalSessionNotFoundError, isSessionNotFoundError } from "@/utils/server-errors"
 import { legacySessionHref, requireServerKey, sessionHref } from "@/utils/session-route"
 import { useUsageExceededDialogs } from "./session/usage-exceeded-dialogs"
-import { createSessionOwnership } from "./session/session-ownership"
 import { createSessionLineage } from "./session/session-lineage"
 
 type FollowupItem = FollowupDraft & { id: string }
@@ -366,15 +365,28 @@ export default function Page() {
   const prompt = usePrompt()
   const comments = useComments()
   const command = useCommand()
-  const terminal = useTerminal()
   const [searchParams, setSearchParams] = useSearchParams<{ prompt?: string }>()
   const location = useLocation()
   const navigate = useNavigate()
-  const { params, sessionKey, workspaceKey, tabs, view } = useSessionLayout()
+  const isDesktop = createMediaQuery("(min-width: 768px)")
+  const newSessionDesign = createMemo(() => settings.general.newLayoutDesigns())
+  const canReview = createMemo(() => !!sync().project)
+  const session = createSessionController({
+    review: isDesktop,
+    hasReview: canReview,
+    fileBrowser: (sessionID) => newSessionDesign() && isDesktop() && !!sessionID,
+  })
+  const params = session.identity.params
+  const sessionKey = session.identity.sessionKey
+  const workspaceKey = session.identity.workspaceKey
+  const tabs = session.layout.tabs
+  const view = session.layout.view
   const reviewMode = () => view().review.mode() ?? "git"
   const reviewFile = () => view().review.file()
-  const sessionOwnership = createSessionOwnership(sessionKey)
-  const newSessionDesign = createMemo(() => settings.general.newLayoutDesigns())
+  const sessionOwnership = session.ownership
+  const info = session.data.info
+  const isChildSession = session.data.isChild
+  const revertMessageID = session.data.revertMessageID
 
   createEffect(() => {
     if (!prompt.ready()) return
@@ -433,8 +445,8 @@ export default function Page() {
         const current = tabs().tabs()
         if (current.all.length > 0 || current.active) return
 
-        const all = normalizeTabs(from.all)
-        const active = from.active ? normalizeTab(from.active) : undefined
+        const all = session.tabs.normalizeAll(from.all)
+        const active = from.active ? session.tabs.normalize(from.active) : undefined
         tabs().setAll(all)
         tabs().setActive(active && all.includes(active) ? active : all[0])
 
@@ -445,7 +457,6 @@ export default function Page() {
     ),
   )
 
-  const isDesktop = createMediaQuery("(min-width: 768px)")
   const size = createSizing()
   const desktopReviewOpen = createMemo(() => isDesktop() && view().reviewPanel.opened())
   const desktopV2ReviewOpen = createMemo(() => newSessionDesign() && desktopReviewOpen() && !!params.id)
@@ -510,46 +521,16 @@ export default function Page() {
     }),
   )
 
-  function normalizeTab(tab: string) {
-    if (!tab.startsWith("file://")) return tab
-    return file.tab(tab)
-  }
-
-  function normalizeTabs(list: string[]) {
-    const seen = new Set<string>()
-    const next: string[] = []
-    for (const item of list) {
-      const value = normalizeTab(item)
-      if (seen.has(value)) continue
-      seen.add(value)
-      next.push(value)
-    }
-    return next
-  }
-
   const openReviewPanel = () => {
     if (!view().reviewPanel.opened()) view().reviewPanel.open()
   }
 
-  const info = createMemo(() => (params.id ? sync().session.get(params.id) : undefined))
-  const isChildSession = createMemo(() => !!info()?.parentID)
-  const canReview = createMemo(() => !!sync().project)
-  const reviewTab = createMemo(() => isDesktop())
-  const tabState = createSessionTabs({
-    tabs,
-    pathFromTab: file.pathFromTab,
-    normalizeTab,
-    review: reviewTab,
-    hasReview: canReview,
-  })
-  const activeTab = tabState.activeTab
-  const activeFileTab = tabState.activeFileTab
-  const revertMessageID = createMemo(() => info()?.revert?.messageID)
-  const timeline = createTimelineModel({ sessionID: () => params.id, revertMessageID })
+  const activeTab = session.tabs.activeTab
+  const activeFileTab = session.tabs.activeFileTab
+  const timeline = createTimelineModel({ session })
   const historyLoading = timeline.history.loading
   const historyMore = timeline.history.more
   const lastUserMessage = timeline.lastUserMessage
-  const messages = timeline.messages
   const messagesReady = timeline.ready
   const sessionSync = timeline.resource
   const userMessages = timeline.userMessages
@@ -1138,11 +1119,10 @@ export default function Page() {
 
   useComposerCommands()
   useSessionCommands({
+    session,
     navigateMessageByOffset,
     setActiveMessage,
     focusInput,
-    review: reviewTab,
-    fileBrowser: () => newSessionDesign() && isDesktop() && !!params.id,
   })
   command.register("session-palette", () => [
     {
@@ -1692,8 +1672,6 @@ export default function Page() {
     })
   }
 
-  const merge = (next: NonNullable<ReturnType<typeof info>>, target = sync()) => target.session.remember(next)
-
   const roll = (sessionID: string, next: NonNullable<ReturnType<typeof info>>["revert"], target = sync()) => {
     const session = target.session.get(sessionID)
     if (!session) return
@@ -1754,7 +1732,7 @@ export default function Page() {
   const queueEnabled = createMemo(() => {
     const id = params.id
     if (!id) return false
-    return settings.general.followup() === "queue" && busy(id) && !composer.blocked() && !isChildSession()
+    return settings.general.followup() === "queue" && session.data.working() && !composer.blocked() && !isChildSession()
   })
 
   const followupText = (item: FollowupDraft) => {
@@ -1932,7 +1910,7 @@ export default function Page() {
     if (followup.paused[sessionID]) return
     if (isChildSession()) return
     if (composer.blocked()) return
-    if (busy(sessionID)) return
+    if (session.data.working()) return
 
     void sendFollowup(sessionID, item.id)
   })
@@ -2080,6 +2058,7 @@ export default function Page() {
             <Show when={messagesReady() ? params.id : undefined} keyed>
               {(_id) => (
                 <MessageTimeline
+                  session={session}
                   actions={actions}
                   scroll={ui.scroll}
                   onResumeScroll={resumeScroll}
@@ -2157,7 +2136,7 @@ export default function Page() {
                 : undefined,
             onResponseSubmit: resumeScroll,
             openParent: () => {
-              const id = info()?.parentID
+              const id = session.data.parentID()
               if (!id) return
               navigate(
                 params.serverKey

packages/app/src/pages/session/session-controller.test.ts

@@ -0,0 +1,71 @@
+import { describe, expect, test } from "bun:test"
+import type { AssistantMessage, Message, UserMessage } from "@opencode-ai/sdk/v2"
+import { createRoot, createSignal } from "solid-js"
+import {
+  normalizeSessionTab,
+  normalizeSessionTabs,
+  selectSessionUserMessages,
+  selectVisibleSessionUserMessages,
+} from "./session-domain"
+import { createSessionOwnership } from "./session-ownership"
+
+const user = (id: string): UserMessage => ({
+  id,
+  sessionID: "session",
+  role: "user",
+  time: { created: 0 },
+  agent: "build",
+  model: { providerID: "provider", modelID: "model" },
+})
+
+const assistant: AssistantMessage = {
+  id: "msg_2",
+  sessionID: "session",
+  role: "assistant",
+  time: { created: 0 },
+  parentID: "msg_1",
+  modelID: "model",
+  providerID: "provider",
+  mode: "build",
+  agent: "build",
+  path: { cwd: "/workspace", root: "/workspace" },
+  cost: 0,
+  tokens: { input: 0, output: 0, reasoning: 0, cache: { read: 0, write: 0 } },
+}
+
+describe("session controller invariants", () => {
+  test("normalizes file tabs once while preserving non-file tabs and order", () => {
+    const normalize = (tab: string) => normalizeSessionTab(tab, (value) => value.toLowerCase())
+
+    expect(normalizeSessionTabs(["review", "file://SRC/A.TS", "file://src/a.ts", "context"], normalize)).toEqual([
+      "review",
+      "file://src/a.ts",
+      "context",
+    ])
+  })
+
+  test("selects user history strictly before the revert boundary", () => {
+    const messages: Message[] = [user("msg_1"), assistant, user("msg_3"), user("msg_5")]
+    const users = selectSessionUserMessages(messages)
+
+    expect(users.map((message) => message.id)).toEqual(["msg_1", "msg_3", "msg_5"])
+    expect(selectVisibleSessionUserMessages(users, "msg_3").map((message) => message.id)).toEqual(["msg_1"])
+    expect(selectVisibleSessionUserMessages(users)).toBe(users)
+  })
+
+  test("rejects work captured by a previous session", () => {
+    createRoot((dispose) => {
+      const [key, setKey] = createSignal("session-a")
+      const ownership = createSessionOwnership(key)
+      const captured = ownership.capture()
+      let ran = false
+
+      setKey("session-b")
+
+      expect(captured.current()).toBe(false)
+      expect(captured.run(() => (ran = true))).toBeUndefined()
+      expect(ran).toBe(false)
+      dispose()
+    })
+  })
+})

packages/app/src/pages/session/session-controller.ts

@@ -0,0 +1,101 @@
+import type { Message, UserMessage } from "@opencode-ai/sdk/v2"
+import { createMemo, type Accessor } from "solid-js"
+import { useFile } from "@/context/file"
+import { useSync } from "@/context/sync"
+import { same } from "@/utils/same"
+import { createSessionTabs } from "./helpers"
+import {
+  normalizeSessionTab,
+  normalizeSessionTabs,
+  selectSessionUserMessages,
+  selectVisibleSessionUserMessages,
+} from "./session-domain"
+import { useSessionLayout } from "./session-layout"
+import { createSessionOwnership } from "./session-ownership"
+
+const emptyMessages: Message[] = []
+const emptyUserMessages: UserMessage[] = []
+const idle = { type: "idle" as const }
+
+export function createSessionController(input: {
+  review?: Accessor<boolean>
+  hasReview?: Accessor<boolean>
+  fileBrowser?: (sessionID: string | undefined) => boolean
+}) {
+  const file = useFile()
+  const sync = useSync()
+  const layout = useSessionLayout()
+  const sessionID = createMemo(() => layout.params.id)
+  const info = createMemo(() => {
+    const id = sessionID()
+    return id ? sync().session.get(id) : undefined
+  })
+  const parentID = createMemo(() => info()?.parentID)
+  const parent = createMemo(() => {
+    const id = parentID()
+    return id ? sync().session.get(id) : undefined
+  })
+  const status = createMemo(() => {
+    const id = sessionID()
+    return id ? (sync().data.session_status[id] ?? idle) : idle
+  })
+  const messages = createMemo(() => {
+    const id = sessionID()
+    return id ? (sync().data.message[id] ?? emptyMessages) : emptyMessages
+  })
+  const userMessages = createMemo(() => selectSessionUserMessages(messages()), emptyUserMessages, { equals: same })
+  const revertMessageID = createMemo(() => info()?.revert?.messageID)
+  const visibleUserMessages = createMemo(
+    () => selectVisibleSessionUserMessages(userMessages(), revertMessageID()),
+    emptyUserMessages,
+    { equals: same },
+  )
+  const normalizeTab = (tab: string) => normalizeSessionTab(tab, file.tab)
+  const tabs = createSessionTabs({
+    tabs: layout.tabs,
+    pathFromTab: file.pathFromTab,
+    normalizeTab,
+    review: input.review,
+    hasReview: input.hasReview,
+    fileBrowser: input.fileBrowser ? () => input.fileBrowser?.(sessionID()) ?? false : undefined,
+  })
+
+  return {
+    identity: {
+      params: layout.params,
+      sessionID,
+      sessionKey: layout.sessionKey,
+      workspaceKey: layout.workspaceKey,
+    },
+    data: {
+      info,
+      parent,
+      parentID,
+      isChild: createMemo(() => !!parentID()),
+      status,
+      working: createMemo(() => {
+        const id = sessionID()
+        return id ? sync().data.session_working(id) : false
+      }),
+      revertMessageID,
+    },
+    history: {
+      messages,
+      userMessages,
+      visibleUserMessages,
+      lastUserMessage: createMemo(() => visibleUserMessages().at(-1)),
+    },
+    layout: {
+      tabs: layout.tabs,
+      view: layout.view,
+    },
+    ownership: createSessionOwnership(layout.sessionKey),
+    tabs: {
+      ...tabs,
+      normalize: normalizeTab,
+      normalizeAll: (values: string[]) => normalizeSessionTabs(values, normalizeTab),
+    },
+  }
+}
+
+export type SessionController = ReturnType<typeof createSessionController>

packages/app/src/pages/session/session-domain.ts

@@ -0,0 +1,19 @@
+import type { Message, UserMessage } from "@opencode-ai/sdk/v2"
+
+export function normalizeSessionTab(tab: string, normalizeFileTab: (tab: string) => string) {
+  if (!tab.startsWith("file://")) return tab
+  return normalizeFileTab(tab)
+}
+
+export function normalizeSessionTabs(tabs: string[], normalize: (tab: string) => string) {
+  return [...new Set(tabs.map(normalize))]
+}
+
+export function selectSessionUserMessages(messages: Message[]) {
+  return messages.filter((message): message is UserMessage => message.role === "user")
+}
+
+export function selectVisibleSessionUserMessages(messages: UserMessage[], revertMessageID?: string) {
+  if (!revertMessageID) return messages
+  return messages.filter((message) => message.id < revertMessageID)
+}

packages/app/src/pages/session/timeline/controller-projection.ts

@@ -0,0 +1,26 @@
+export function timelineChildTitle(input: {
+  parentID?: string
+  taskDescription?: string
+  title?: string
+  fallback: string
+}) {
+  if (!input.parentID) return input.title ?? ""
+  if (input.taskDescription) return input.taskDescription
+  return input.title?.replace(/\s+\(@[^)]+ subagent\)$/, "") || input.fallback
+}
+
+export function timelineRemovedSessionIDs(sessions: readonly { id: string; parentID?: string }[], sessionID: string) {
+  const removed = new Set([sessionID])
+  const byParent = Map.groupBy(
+    sessions.filter((session) => session.parentID),
+    (session) => session.parentID!,
+  )
+  const visit = (id: string) =>
+    byParent.get(id)?.forEach((child) => {
+      if (removed.has(child.id)) return
+      removed.add(child.id)
+      visit(child.id)
+    })
+  visit(sessionID)
+  return removed
+}

packages/app/src/pages/session/timeline/controller.test.ts

@@ -0,0 +1,30 @@
+import { describe, expect, test } from "bun:test"
+import { timelineChildTitle, timelineRemovedSessionIDs } from "./controller-projection"
+
+describe("timeline controller", () => {
+  test("projects child titles from task descriptions and session fallbacks", () => {
+    expect(timelineChildTitle({ title: "Root", fallback: "New session" })).toBe("Root")
+    expect(
+      timelineChildTitle({ parentID: "parent", taskDescription: "Investigate timeline", fallback: "New session" }),
+    ).toBe("Investigate timeline")
+    expect(
+      timelineChildTitle({ parentID: "parent", title: "Fallback (@build subagent)", fallback: "New session" }),
+    ).toBe("Fallback")
+    expect(timelineChildTitle({ parentID: "parent", fallback: "New session" })).toBe("New session")
+  })
+
+  test("collects the removed session and all descendants", () => {
+    const removed = timelineRemovedSessionIDs(
+      [
+        { id: "root" },
+        { id: "child", parentID: "root" },
+        { id: "grandchild", parentID: "child" },
+        { id: "sibling", parentID: "root" },
+        { id: "unrelated" },
+      ],
+      "root",
+    )
+
+    expect([...removed]).toEqual(["root", "child", "grandchild", "sibling"])
+  })
+})

packages/app/src/pages/session/timeline/controller.tsx

@@ -0,0 +1,328 @@
+import type { Message, Part, UserMessage } from "@opencode-ai/sdk/v2"
+import { Button } from "@opencode-ai/ui/button"
+import { Dialog } from "@opencode-ai/ui/dialog"
+import { DialogFooter, DialogHeader, DialogTitleGroup, DialogV2 } from "@opencode-ai/ui/v2/dialog-v2"
+import { ButtonV2 } from "@opencode-ai/ui/v2/button-v2"
+import { useNavigate } from "@solidjs/router"
+import { createEffect, createMemo, on, type Accessor } from "solid-js"
+import { createStore, produce } from "solid-js/store"
+import { notifySessionTabsRemoved } from "@/components/titlebar-session-events"
+import { useDialog } from "@opencode-ai/ui/context/dialog"
+import { useLanguage } from "@/context/language"
+import { usePlatform } from "@/context/platform"
+import { useServerSDK } from "@/context/server-sdk"
+import { useSettings } from "@/context/settings"
+import { useSDK } from "@/context/sdk"
+import { useSync } from "@/context/sync"
+import { useTabs } from "@/context/tabs"
+import type { SessionController } from "@/pages/session/session-controller"
+import { legacySessionHref, requireServerKey, sessionHref } from "@/utils/session-route"
+import { sessionTitle } from "@/utils/session-title"
+import { showToast } from "@/utils/toast"
+import { timelineChildTitle, timelineRemovedSessionIDs } from "./controller-projection"
+import { createTimelineProjection } from "./projection"
+
+const emptyMessages: Message[] = []
+const emptyParts: Part[] = []
+const taskDescription = (part: Part, sessionID: string): string | undefined => {
+  if (part.type !== "tool" || part.tool !== "task") return undefined
+  const metadata = "metadata" in part.state ? part.state.metadata : undefined
+  if (metadata?.sessionId !== sessionID) return undefined
+  const value = part.state.input?.description
+  if (typeof value === "string" && value) return value
+  return undefined
+}
+
+export type TimelineSessionSource = {
+  identity: Pick<SessionController["identity"], "params" | "sessionID" | "sessionKey">
+  data: Pick<SessionController["data"], "info" | "parent" | "parentID" | "status">
+  history: Pick<SessionController["history"], "messages">
+}
+
+export function createTimelineController(input: {
+  session: TimelineSessionSource
+  userMessages: Accessor<UserMessage[]>
+}) {
+  const navigate = useNavigate()
+  const serverSDK = useServerSDK()
+  const sdk = useSDK()
+  const sync = useSync()
+  const settings = useSettings()
+  const tabs = useTabs()
+  const dialog = useDialog()
+  const language = useLanguage()
+  const platform = usePlatform()
+  const params = input.session.identity.params
+  const sessionKey = input.session.identity.sessionKey
+  const sessionID = input.session.identity.sessionID
+  const status = input.session.data.status
+  const messages = input.session.history.messages
+  const projectedMessages = createMemo(() => {
+    const id = sessionID()
+    if (!id) return []
+    const visible = new Set(input.userMessages().map((message) => message.id))
+    const boundary = messages().find((message) => message.role === "user" && !visible.has(message.id))?.id
+    const projected = sync().data.session_message[id] ?? []
+    return boundary ? projected.filter((message) => message.id < boundary) : projected
+  })
+  const info = input.session.data.info
+  const titleValue = createMemo(() => info()?.title)
+  const titleLabel = createMemo(() => sessionTitle(titleValue()))
+  const shareUrl = createMemo(() => info()?.share?.url)
+  const shareEnabled = createMemo(() => sync().data.config.share !== "disabled")
+  const parentID = input.session.data.parentID
+  const parent = input.session.data.parent
+  const parentMessages = createMemo(() => {
+    const id = parentID()
+    return id ? (sync().data.message[id] ?? emptyMessages) : emptyMessages
+  })
+  const parentTitle = createMemo(() => sessionTitle(parent()?.title) ?? language.t("command.session.new"))
+  const parts = (messageID: string) => sync().data.part[messageID] ?? emptyParts
+  const part = (messageID: string, partID: string) => parts(messageID).find((item) => item.id === partID)
+  const childTaskDescription = createMemo(() => {
+    const id = sessionID()
+    if (!id) return undefined
+    return parentMessages()
+      .flatMap((message) => parts(message.id))
+      .map((item) => taskDescription(item, id))
+      .findLast((value): value is string => !!value)
+  })
+  const childTitle = createMemo(() => {
+    return timelineChildTitle({
+      parentID: parentID(),
+      taskDescription: childTaskDescription(),
+      title: titleLabel(),
+      fallback: language.t("command.session.new"),
+    })
+  })
+  const showHeader = createMemo(() => !!(titleValue() || parentID()))
+  const projection = createTimelineProjection({
+    messages,
+    userMessages: input.userMessages,
+    sessionMessages: projectedMessages,
+    parts,
+    status,
+    showReasoningSummaries: settings.general.showReasoningSummaries,
+    inlineComments: settings.general.newLayoutDesigns,
+  })
+  const [pending, setPending] = createStore({ rename: false, share: false, unshare: false })
+
+  const errorMessage = (error: unknown) => {
+    if (error && typeof error === "object" && "data" in error) {
+      const data = error.data
+      if (data && typeof data === "object" && "message" in data && typeof data.message === "string") return data.message
+    }
+    if (error instanceof Error) return error.message
+    return language.t("common.requestFailed")
+  }
+  const rename = async (title: string) => {
+    const id = sessionID()
+    if (!id || pending.rename) return false
+    const next = title.trim()
+    if (!next || next === (titleLabel() ?? "")) return true
+    setPending("rename", true)
+    const success = await sdk()
+      .api.session.rename({ sessionID: id, title: next })
+      .then(() => true)
+      .catch((error) => {
+        showToast({ title: language.t("common.requestFailed"), description: errorMessage(error) })
+        return false
+      })
+    setPending("rename", false)
+    if (!success) return false
+    sync().set(
+      produce((draft) => {
+        const index = draft.session.findIndex((session) => session.id === id)
+        if (index !== -1) draft.session[index].title = next
+      }),
+    )
+    return true
+  }
+  const share = async () => {
+    const id = sessionID()
+    if (!id || pending.share || !shareEnabled()) return
+    setPending("share", true)
+    await serverSDK()
+      .client.session.share({ sessionID: id })
+      .catch((error) => console.error("Failed to share session", error))
+    setPending("share", false)
+  }
+  const unshare = async () => {
+    const id = sessionID()
+    if (!id || pending.unshare || !shareEnabled()) return
+    setPending("unshare", true)
+    await serverSDK()
+      .client.session.unshare({ sessionID: id })
+      .catch((error) => console.error("Failed to unshare session", error))
+    setPending("unshare", false)
+  }
+  const href = (id: string) =>
+    params.serverKey ? sessionHref(requireServerKey(params.serverKey), id) : legacySessionHref(sdk().directory, id)
+  const navigateAfterRemoval = (id: string, parent?: string, next?: string) => {
+    if (params.id !== id) return
+    if (parent) return navigate(href(parent))
+    if (next) return navigate(href(next))
+    if (params.serverKey)
+      return tabs.newDraft({ server: requireServerKey(params.serverKey), directory: sdk().directory })
+    navigate(`/${params.dir}/session`)
+  }
+  const archive = async (id: string) => {
+    const session = sync().session.get(id)
+    if (!session || (await sdk().protocol) !== "v1") return
+    const index = sync().data.session.findIndex((item) => item.id === id)
+    const next = index === -1 ? undefined : (sync().data.session[index + 1] ?? sync().data.session[index - 1])
+    await sdk()
+      .client.session.update({ sessionID: id, directory: sdk().directory, time: { archived: Date.now() } })
+      .then(() => {
+        sync().set(
+          produce((draft) => {
+            const index = draft.session.findIndex((item) => item.id === id)
+            if (index !== -1) draft.session.splice(index, 1)
+          }),
+        )
+        sync().session.evict(id)
+        void navigateAfterRemoval(id, session.parentID, next?.id)
+        notifySessionTabsRemoved({ directory: sdk().directory, sessionIDs: [id] })
+      })
+      .catch((error) => showToast({ title: language.t("common.requestFailed"), description: errorMessage(error) }))
+  }
+  const remove = async (id: string) => {
+    const session = sync().session.get(id)
+    if (!session) return false
+    const sessions = sync().data.session.filter((item) => !item.parentID && !item.time?.archived)
+    const index = sessions.findIndex((item) => item.id === id)
+    const next = index === -1 ? undefined : (sessions[index + 1] ?? sessions[index - 1])
+    const success = await sdk()
+      .api.session.remove({ sessionID: id })
+      .then(() => true)
+      .catch((error) => {
+        showToast({ title: language.t("session.delete.failed.title"), description: errorMessage(error) })
+        return false
+      })
+    if (!success) return false
+    const removed = timelineRemovedSessionIDs(sync().data.session, id)
+    void navigateAfterRemoval(id, session.parentID, next?.id)
+    sync().set(produce((draft) => void (draft.session = draft.session.filter((item) => !removed.has(item.id)))))
+    removed.forEach((sessionID) => sync().session.evict(sessionID))
+    notifySessionTabsRemoved({ directory: sdk().directory, sessionIDs: [...removed] })
+    return true
+  }
+
+  function DeleteDialog(props: { sessionID: string }) {
+    const name = createMemo(
+      () => sessionTitle(sync().session.get(props.sessionID)?.title) ?? language.t("command.session.new"),
+    )
+    const confirm = async () => {
+      await remove(props.sessionID)
+      dialog.close()
+    }
+    if (settings.general.newLayoutDesigns())
+      return (
+        <DialogV2 fit>
+          <DialogHeader hideClose>
+            <DialogTitleGroup
+              title={language.t("session.delete.title")}
+              description={language.t("session.delete.confirm", { name: name() })}
+            />
+          </DialogHeader>
+          <DialogFooter>
+            <ButtonV2 variant="ghost" onClick={() => dialog.close()}>
+              {language.t("common.cancel")}
+            </ButtonV2>
+            <ButtonV2 variant="danger" onClick={confirm}>
+              {language.t("session.delete.button")}
+            </ButtonV2>
+          </DialogFooter>
+        </DialogV2>
+      )
+    return (
+      <Dialog title={language.t("session.delete.title")} fit>
+        <div class="flex flex-col gap-4 pl-6 pr-2.5 pb-3">
+          <div class="flex flex-col gap-1">
+            <span class="text-14-regular text-text-strong">
+              {language.t("session.delete.confirm", { name: name() })}
+            </span>
+          </div>
+          <div class="flex justify-end gap-2">
+            <Button variant="ghost" size="large" onClick={() => dialog.close()}>
+              {language.t("common.cancel")}
+            </Button>
+            <Button variant="primary" size="large" onClick={confirm}>
+              {language.t("session.delete.button")}
+            </Button>
+          </div>
+        </div>
+      </Dialog>
+    )
+  }
+
+  createEffect(
+    on(
+      () => [parentID(), childTaskDescription()] as const,
+      ([id, description]) => {
+        if (!id || description || sync().data.message[id] !== undefined) return
+        void sync().session.sync(id)
+      },
+      { defer: true },
+    ),
+  )
+
+  return {
+    data: {
+      sessionKey,
+      sessionID,
+      status,
+      titleValue,
+      titleLabel,
+      shareUrl,
+      shareEnabled,
+      parentID,
+      parentTitle,
+      childTitle,
+      showHeader,
+      parts,
+      part,
+      projection,
+      newLayoutDesigns: settings.general.newLayoutDesigns,
+      showReasoningSummaries: settings.general.showReasoningSummaries,
+      shellToolPartsExpanded: settings.general.shellToolPartsExpanded,
+      editToolPartsExpanded: settings.general.editToolPartsExpanded,
+    },
+    pending: {
+      rename: () => pending.rename,
+      share: () => pending.share,
+      unshare: () => pending.unshare,
+    },
+    action: {
+      rename,
+      share,
+      unshare,
+      archive,
+      showDelete: (id: string) => dialog.show(() => <DeleteDialog sessionID={id} />),
+      navigateParent: () => {
+        const id = parentID()
+        if (id) navigate(href(id))
+      },
+      viewShare: () => {
+        const url = shareUrl()
+        if (url) platform.openLink(url)
+      },
+      copyShareUrl: async () => {
+        const url = shareUrl()
+        if (!url) return
+        await navigator.clipboard.writeText(url).then(
+          () =>
+            showToast({
+              variant: "success",
+              icon: "circle-check",
+              title: language.t("session.share.copy.copied"),
+              description: url,
+            }),
+          (error) => showToast({ title: language.t("common.requestFailed"), description: errorMessage(error) }),
+        )
+      },
+    },
+  }
+}
+
+export type TimelineController = ReturnType<typeof createTimelineController>

packages/app/src/pages/session/timeline/message-timeline.tsx

@@ -11,10 +11,8 @@ import {
   type Accessor,
   type JSX,
 } from "solid-js"
-import { createStore, produce } from "solid-js/store"
+import { createStore } from "solid-js/store"
 import { Dynamic } from "solid-js/web"
-import { useNavigate } from "@solidjs/router"
-import { useMutation } from "@tanstack/solid-query"
 import { createVirtualizer, defaultRangeExtractor, elementScroll, type VirtualItem } from "@tanstack/solid-virtual"
 import { Accordion } from "@opencode-ai/ui/accordion"
 import { Button } from "@opencode-ai/ui/button"
@@ -35,8 +33,6 @@ import { Icon as IconV2 } from "@opencode-ai/ui/v2/icon"
 import { IconButtonV2 } from "@opencode-ai/ui/v2/icon-button-v2"
 import { DropdownMenu } from "@opencode-ai/ui/dropdown-menu"
 import { MenuV2 } from "@opencode-ai/ui/v2/menu-v2"
-import { Dialog } from "@opencode-ai/ui/dialog"
-import { DialogFooter, DialogHeader, DialogTitleGroup, DialogV2 } from "@opencode-ai/ui/v2/dialog-v2"
 import { InlineInput } from "@opencode-ai/ui/inline-input"
 import { ButtonV2 } from "@opencode-ai/ui/v2/button-v2"
 import { SessionRetry } from "@opencode-ai/session-ui/session-retry"
@@ -45,43 +41,22 @@ import { StickyAccordionHeader } from "@opencode-ai/ui/sticky-accordion-header"
 import { TextField } from "@opencode-ai/ui/text-field"
 import { TextReveal } from "@opencode-ai/ui/text-reveal"
 import { TextShimmer } from "@opencode-ai/ui/text-shimmer"
-import type {
-  AssistantMessage,
-  Message as MessageType,
-  Part as PartType,
-  ToolPart,
-  UserMessage,
-} from "@opencode-ai/sdk/v2"
-import { showToast } from "@/utils/toast"
+import type { AssistantMessage, ToolPart, UserMessage } from "@opencode-ai/sdk/v2"
 import { getDirectory, getFilename } from "@opencode-ai/core/util/path"
 import { Popover as KobaltePopover } from "@kobalte/core/popover"
 import { normalize } from "@opencode-ai/session-ui/session-diff"
 import { useFileComponent } from "@opencode-ai/ui/context/file"
 import { shouldMarkBoundaryGesture, normalizeWheelDelta } from "@/pages/session/message-gesture"
 import { SessionContextUsage } from "@/components/session-context-usage"
-import { useDialog } from "@opencode-ai/ui/context/dialog"
 import { useLanguage } from "@/context/language"
-import { useSessionKey } from "@/pages/session/session-layout"
-import { useServerSDK } from "@/context/server-sdk"
-import { usePlatform } from "@/context/platform"
-import { useSettings } from "@/context/settings"
-import { useTabs } from "@/context/tabs"
-import { legacySessionHref, requireServerKey, sessionHref } from "@/utils/session-route"
-import { useSDK } from "@/context/sdk"
-import { useSync } from "@/context/sync"
-import { notifySessionTabsRemoved } from "@/components/titlebar-session-events"
-import { sessionTitle } from "@/utils/session-title"
 import { scheduleConnectedMeasure } from "./measure"
 import { observeElementOffsetReconnectAware } from "./observe-element-offset"
-import { createTimelineProjection } from "./projection"
 import { MessageComment, SummaryDiff, TimelineRow, TimelineRowMap } from "./rows"
 import { filterVirtualIndexes } from "./virtual-items"
+import { createTimelineController, type TimelineController, type TimelineSessionSource } from "./controller"
 
-const emptyMessages: MessageType[] = []
-const emptyParts: PartType[] = []
 const emptyTools: ToolPart[] = []
 const emptyAssistantMessages: AssistantMessage[] = []
-const idle = { type: "idle" as const }
 
 type FramedTimelineRow = Exclude<TimelineRow.TimelineRow, { _tag: "TurnGap" }>
 type TimelineRowByTag<T extends TimelineRow.TimelineRow["_tag"]> = Extract<TimelineRow.TimelineRow, { _tag: T }>
@@ -89,14 +64,6 @@ type TimelineRowByTag<T extends TimelineRow.TimelineRow["_tag"]> = Extract<Timel
 const timelineFallbackItemSize = 60
 const timelineCache = new Map<string, { measurements: VirtualItem[]; toolOpen: Record<string, boolean | undefined> }>()
 
-const taskDescription = (part: PartType, sessionID: string) => {
-  if (part.type !== "tool" || part.tool !== "task") return
-  const metadata = "metadata" in part.state ? part.state.metadata : undefined
-  if (metadata?.sessionId !== sessionID) return
-  const value = part.state.input?.description
-  if (typeof value === "string" && value) return value
-}
-
 const boundaryTarget = (root: HTMLElement, target: EventTarget | null) => {
   const current = target instanceof Element ? target : undefined
   const nested = current?.closest("[data-scrollable]")
@@ -237,7 +204,8 @@ function TimelineDiffView(props: { diff: SummaryDiff }) {
   )
 }
 
-export function MessageTimeline(props: {
+type MessageTimelineProps = {
+  session: TimelineSessionSource
   actions?: UserActions
   scroll: { overflow: boolean; bottom: boolean; jump: boolean }
   onResumeScroll: () => void
@@ -257,88 +225,42 @@ export function MessageTimeline(props: {
   setRevealMessage?: (fn: (id: string) => void) => void
   setScrollToEnd?: (fn: () => void) => void
   setHistoryAnchor?: (handlers: { capture: () => void; restore: (done: boolean) => void }) => void
-}) {
-  let touchGesture: number | undefined
+}
 
-  const navigate = useNavigate()
-  const serverSDK = useServerSDK()
-  const sdk = useSDK()
-  const sync = useSync()
-  const settings = useSettings()
-  const tabs = useTabs()
-  const dialog = useDialog()
+export function MessageTimeline(props: MessageTimelineProps) {
+  const controller = createTimelineController({ session: props.session, userMessages: () => props.userMessages })
+  return (
+    <MessageTimelineView {...props} data={controller.data} action={controller.action} pending={controller.pending} />
+  )
+}
+
+function MessageTimelineView(
+  props: MessageTimelineProps & {
+    data: TimelineController["data"]
+    action: TimelineController["action"]
+    pending: TimelineController["pending"]
+  },
+) {
+  let touchGesture: number | undefined
   const language = useLanguage()
-  const { params, sessionKey } = useSessionKey()
-  const ownerSessionKey = sessionKey()
+  const ownerSessionKey = props.data.sessionKey()
   const cached = timelineCache.get(ownerSessionKey)
   const initialMeasurements = cached?.measurements
   const coldBottomMount = !initialMeasurements?.length && props.shouldAnchorBottom()
-  const platform = usePlatform()
 
   const [listRoot, setListRoot] = createSignal<HTMLDivElement>()
-  const sessionID = createMemo(() => params.id)
-  const sessionStatus = createMemo(() => {
-    const id = sessionID()
-    if (!id) return idle
-    return sync().data.session_status[id] ?? idle
-  })
-  const sessionMessages = createMemo(() => (sessionID() ? (sync().data.message[sessionID()!] ?? []) : []))
-  const projectedMessages = createMemo(() => {
-    const id = sessionID()
-    if (!id) return []
-    const visible = new Set(props.userMessages.map((message) => message.id))
-    const boundary = sessionMessages().find((message) => message.role === "user" && !visible.has(message.id))?.id
-    const messages = sync().data.session_message[id] ?? []
-    return boundary ? messages.filter((message) => message.id < boundary) : messages
-  })
-  const info = createMemo(() => {
-    const id = sessionID()
-    if (!id) return
-    return sync().session.get(id)
-  })
-  const titleValue = createMemo(() => info()?.title)
-  const titleLabel = createMemo(() => sessionTitle(titleValue()))
-  const shareUrl = createMemo(() => info()?.share?.url)
-  const shareEnabled = createMemo(() => sync().data.config.share !== "disabled")
-  const parentID = createMemo(() => info()?.parentID)
-  const parent = createMemo(() => {
-    const id = parentID()
-    if (!id) return
-    return sync().session.get(id)
-  })
-  const parentMessages = createMemo(() => {
-    const id = parentID()
-    if (!id) return emptyMessages
-    return sync().data.message[id] ?? emptyMessages
-  })
-  const parentTitle = createMemo(() => sessionTitle(parent()?.title) ?? language.t("command.session.new"))
-  const getMsgParts = (msgId: string) => sync().data.part[msgId] ?? emptyParts
-  const getMsgPart = (messageID: string, partID: string) => getMsgParts(messageID).find((part) => part.id === partID)
-  const childTaskDescription = createMemo(() => {
-    const id = sessionID()
-    if (!id) return
-    return parentMessages()
-      .flatMap((message) => getMsgParts(message.id))
-      .map((part) => taskDescription(part, id))
-      .findLast((value): value is string => !!value)
-  })
-  const childTitle = createMemo(() => {
-    if (!parentID()) return titleLabel() ?? ""
-    if (childTaskDescription()) return childTaskDescription()
-    const value = titleLabel()?.replace(/\s+\(@[^)]+ subagent\)$/, "")
-    if (value) return value
-    return language.t("command.session.new")
-  })
-  const showHeader = createMemo(() => !!(titleValue() || parentID()))
-  const projection = createTimelineProjection({
-    messages: sessionMessages,
-    userMessages: () => props.userMessages,
-    sessionMessages: projectedMessages,
-    parts: getMsgParts,
-    status: sessionStatus,
-    showReasoningSummaries: settings.general.showReasoningSummaries,
-    inlineComments: settings.general.newLayoutDesigns,
-  })
+  const sessionID = props.data.sessionID
+  const sessionStatus = props.data.status
+  const titleLabel = props.data.titleLabel
+  const shareUrl = props.data.shareUrl
+  const shareEnabled = props.data.shareEnabled
+  const parentID = props.data.parentID
+  const parentTitle = props.data.parentTitle
+  const childTitle = props.data.childTitle
+  const showHeader = props.data.showHeader
+  const getMsgParts = props.data.parts
+  const getMsgPart = props.data.part
+  const projection = props.data.projection
   const activeMessageID = projection.activeMessageID
   const assistantMessagesByParent = projection.assistantMessagesByParent
   const lastAssistantGroupKey = projection.lastAssistantGroupKey
@@ -528,9 +450,9 @@ export function MessageTimeline(props: {
     virtualizer.scrollToEnd()
   }
 
-  let measuredSessionKey = sessionKey()
+  let measuredSessionKey = props.data.sessionKey()
   createEffect(() => {
-    const key = sessionKey()
+    const key = props.data.sessionKey()
     timelineRows().length
     if (measuredSessionKey !== key) {
       measuredSessionKey = key
@@ -643,88 +565,6 @@ export function MessageTimeline(props: {
     props.setScrollRef(undefined)
   })
 
-  const viewShare = () => {
-    const url = shareUrl()
-    if (!url) return
-    platform.openLink(url)
-  }
-
-  const errorMessage = (err: unknown) => {
-    if (err && typeof err === "object" && "data" in err) {
-      const data = (err as { data?: { message?: string } }).data
-      if (data?.message) return data.message
-    }
-    if (err instanceof Error) return err.message
-    return language.t("common.requestFailed")
-  }
-
-  const shareMutation = useMutation(() => ({
-    mutationFn: (id: string) => serverSDK().client.session.share({ sessionID: id }),
-    onError: (err) => {
-      console.error("Failed to share session", err)
-    },
-  }))
-
-  const unshareMutation = useMutation(() => ({
-    mutationFn: (id: string) => serverSDK().client.session.unshare({ sessionID: id }),
-    onError: (err) => {
-      console.error("Failed to unshare session", err)
-    },
-  }))
-
-  const titleMutation = useMutation(() => ({
-    mutationFn: (input: { id: string; title: string }) =>
-      sdk().api.session.rename({ sessionID: input.id, title: input.title }),
-    onSuccess: (_, input) => {
-      sync().set(
-        produce((draft) => {
-          const index = draft.session.findIndex((s) => s.id === input.id)
-          if (index !== -1) draft.session[index].title = input.title
-        }),
-      )
-      setTitle("editing", false)
-    },
-    onError: (err) => {
-      showToast({
-        title: language.t("common.requestFailed"),
-        description: errorMessage(err),
-      })
-    },
-  }))
-
-  const shareSession = () => {
-    const id = sessionID()
-    if (!id || shareMutation.isPending) return
-    if (!shareEnabled()) return
-    shareMutation.mutate(id)
-  }
-
-  const unshareSession = () => {
-    const id = sessionID()
-    if (!id || unshareMutation.isPending) return
-    if (!shareEnabled()) return
-    unshareMutation.mutate(id)
-  }
-  const copyShareUrl = () => {
-    const url = shareUrl()
-    if (!url) return
-    void navigator.clipboard
-      .writeText(url)
-      .then(() =>
-        showToast({
-          variant: "success",
-          icon: "circle-check",
-          title: language.t("session.share.copy.copied"),
-          description: url,
-        }),
-      )
-      .catch((err: unknown) =>
-        showToast({
-          title: language.t("common.requestFailed"),
-          description: errorMessage(err),
-        }),
-      )
-  }
   const selectShareUrlText: JSX.EventHandler<HTMLDivElement, MouseEvent> = (event) => {
     const selection = window.getSelection()
     if (!selection) return
@@ -736,7 +576,7 @@ export function MessageTimeline(props: {
 
   createEffect(
     on(
-      sessionKey,
+      props.data.sessionKey,
       () =>
         setTitle({
           draft: "",
@@ -749,18 +589,6 @@ export function MessageTimeline(props: {
     ),
   )
 
-  createEffect(
-    on(
-      () => [parentID(), childTaskDescription()] as const,
-      ([id, description]) => {
-        if (!id || description) return
-        if (sync().data.message[id] !== undefined) return
-        void sync().session.sync(id)
-      },
-      { defer: true },
-    ),
-  )
-
   const openTitleEditor = () => {
     if (!sessionID() || parentID()) return
     setTitle({ editing: true, draft: titleLabel() ?? "" })
@@ -772,193 +600,12 @@ export function MessageTimeline(props: {
   }
 
   const closeTitleEditor = () => {
-    if (titleMutation.isPending) return
+    if (props.pending.rename()) return
     setTitle("editing", false)
   }
 
-  const saveTitleEditor = () => {
-    const id = sessionID()
-    if (!id) return
-    if (titleMutation.isPending) return
-
-    const next = title.draft.trim()
-    if (!next || next === (titleLabel() ?? "")) {
-      setTitle("editing", false)
-      return
-    }
-
-    titleMutation.mutate({ id, title: next })
-  }
-
-  const navigateAfterSessionRemoval = (sessionID: string, parentID?: string, nextSessionID?: string) => {
-    if (params.id !== sessionID) return
-    const href = (id: string) =>
-      params.serverKey ? sessionHref(requireServerKey(params.serverKey), id) : legacySessionHref(sdk().directory, id)
-    if (parentID) {
-      navigate(href(parentID))
-      return
-    }
-    if (nextSessionID) {
-      navigate(href(nextSessionID))
-      return
-    }
-    if (params.serverKey) {
-      tabs.newDraft({ server: requireServerKey(params.serverKey), directory: sdk().directory })
-      return
-    }
-    navigate(`/${params.dir}/session`)
-  }
-
-  const archiveSession = async (sessionID: string) => {
-    const session = sync().session.get(sessionID)
-    if (!session) return
-    if ((await sdk().protocol) !== "v1") return
-
-    const sessions = sync().data.session ?? []
-    const index = sessions.findIndex((s) => s.id === sessionID)
-    const nextSession = index === -1 ? undefined : (sessions[index + 1] ?? sessions[index - 1])
-
-    await sdk()
-      .client.session.update({ sessionID, directory: sdk().directory, time: { archived: Date.now() } })
-      .then(() => {
-        sync().set(
-          produce((draft) => {
-            const index = draft.session.findIndex((s) => s.id === sessionID)
-            if (index !== -1) draft.session.splice(index, 1)
-          }),
-        )
-        sync().session.evict(sessionID)
-        navigateAfterSessionRemoval(sessionID, session.parentID, nextSession?.id)
-        notifySessionTabsRemoved({ directory: sdk().directory, sessionIDs: [sessionID] })
-      })
-      .catch((err) => {
-        showToast({
-          title: language.t("common.requestFailed"),
-          description: errorMessage(err),
-        })
-      })
-  }
-
-  const deleteSession = async (sessionID: string) => {
-    const session = sync().session.get(sessionID)
-    if (!session) return false
-
-    const sessions = (sync().data.session ?? []).filter((s) => !s.parentID && !s.time?.archived)
-    const index = sessions.findIndex((s) => s.id === sessionID)
-    const nextSession = index === -1 ? undefined : (sessions[index + 1] ?? sessions[index - 1])
-
-    const result = await sdk()
-      .api.session.remove({ sessionID })
-      .then(() => true)
-      .catch((err) => {
-        showToast({
-          title: language.t("session.delete.failed.title"),
-          description: errorMessage(err),
-        })
-        return false
-      })
-
-    if (!result) return false
-
-    const removed = new Set<string>([sessionID])
-    const byParent = new Map<string, string[]>()
-    for (const item of sync().data.session) {
-      const parentID = item.parentID
-      if (!parentID) continue
-      const existing = byParent.get(parentID)
-      if (existing) {
-        existing.push(item.id)
-        continue
-      }
-      byParent.set(parentID, [item.id])
-    }
-
-    const stack = [sessionID]
-    while (stack.length) {
-      const parentID = stack.pop()
-      if (!parentID) continue
-
-      const children = byParent.get(parentID)
-      if (!children) continue
-
-      for (const child of children) {
-        if (removed.has(child)) continue
-        removed.add(child)
-        stack.push(child)
-      }
-    }
-
-    navigateAfterSessionRemoval(sessionID, session.parentID, nextSession?.id)
-
-    sync().set(
-      produce((draft) => {
-        draft.session = draft.session.filter((s) => !removed.has(s.id))
-      }),
-    )
-
-    for (const id of removed) {
-      sync().session.evict(id)
-    }
-    notifySessionTabsRemoved({ directory: sdk().directory, sessionIDs: [...removed] })
-    return true
-  }
-
-  const navigateParent = () => {
-    const id = parentID()
-    if (!id) return
-    navigate(
-      params.serverKey ? sessionHref(requireServerKey(params.serverKey), id) : legacySessionHref(sdk().directory, id),
-    )
-  }
-
-  function DialogDeleteSession(props: { sessionID: string }) {
-    const name = createMemo(
-      () => sessionTitle(sync().session.get(props.sessionID)?.title) ?? language.t("command.session.new"),
-    )
-    const handleDelete = async () => {
-      await deleteSession(props.sessionID)
-      dialog.close()
-    }
-
-    if (settings.general.newLayoutDesigns())
-      return (
-        <DialogV2 fit>
-          <DialogHeader hideClose>
-            <DialogTitleGroup
-              title={language.t("session.delete.title")}
-              description={language.t("session.delete.confirm", { name: name() })}
-            />
-          </DialogHeader>
-          <DialogFooter>
-            <ButtonV2 variant="ghost" onClick={() => dialog.close()}>
-              {language.t("common.cancel")}
-            </ButtonV2>
-            <ButtonV2 variant="danger" onClick={handleDelete}>
-              {language.t("session.delete.button")}
-            </ButtonV2>
-          </DialogFooter>
-        </DialogV2>
-      )
-
-    return (
-      <Dialog title={language.t("session.delete.title")} fit>
-        <div class="flex flex-col gap-4 pl-6 pr-2.5 pb-3">
-          <div class="flex flex-col gap-1">
-            <span class="text-14-regular text-text-strong">
-              {language.t("session.delete.confirm", { name: name() })}
-            </span>
-          </div>
-          <div class="flex justify-end gap-2">
-            <Button variant="ghost" size="large" onClick={() => dialog.close()}>
-              {language.t("common.cancel")}
-            </Button>
-            <Button variant="primary" size="large" onClick={handleDelete}>
-              {language.t("session.delete.button")}
-            </Button>
-          </div>
-        </div>
-      </Dialog>
-    )
+  const saveTitleEditor = async () => {
+    if (await props.action.rename(title.draft)) setTitle("editing", false)
   }
 
   const workingTurn = (userMessageID: string) => sessionStatus().type !== "idle" && activeMessageID() === userMessageID
@@ -1037,7 +684,7 @@ export function MessageTimeline(props: {
     const defaultOpen = createMemo(() => {
       const item = part()
       if (!item) return
-      return partDefaultOpen(item, settings.general.shellToolPartsExpanded(), settings.general.editToolPartsExpanded())
+      return partDefaultOpen(item, props.data.shellToolPartsExpanded(), props.data.editToolPartsExpanded())
     })
 
     return (
@@ -1050,7 +697,7 @@ export function MessageTimeline(props: {
                 message={message()}
                 showAssistantCopyPartID={assistantCopyPartID(row().userMessageID)}
                 turnDurationMs={turnDurationMs(row().userMessageID)}
-                useV2Actions={settings.general.newLayoutDesigns()}
+                useV2Actions={props.data.newLayoutDesigns()}
                 defaultOpen={defaultOpen()}
                 toolOpen={toolOpen[part().id] ?? defaultOpen()}
                 onToolOpenChange={(open) => setToolOpen(part().id, open)}
@@ -1113,8 +760,8 @@ export function MessageTimeline(props: {
                       <div
                         classList={{
                           "shrink-0 max-w-[260px] rounded-[6px] border-border-weak-base bg-background-stronger px-2.5 py-2": true,
-                          "border-[0.5px]": settings.general.newLayoutDesigns(),
-                          border: !settings.general.newLayoutDesigns(),
+                          "border-[0.5px]": props.data.newLayoutDesigns(),
+                          border: !props.data.newLayoutDesigns(),
                         }}
                       >
                         <div class="flex items-center gap-1.5 min-w-0 text-11-medium text-text-strong">
@@ -1149,7 +796,7 @@ export function MessageTimeline(props: {
           if (m?.role === "user") return m
         })
         const messageComments = createMemo(() => {
-          if (!settings.general.newLayoutDesigns()) return []
+          if (!props.data.newLayoutDesigns()) return []
           return getMsgParts(userMessageRow().userMessageID).flatMap((part) => MessageComment.fromPart(part) ?? [])
         })
         return (
@@ -1162,7 +809,7 @@ export function MessageTimeline(props: {
                       message={message()}
                       parts={getMsgParts(userMessageRow().userMessageID)}
                       actions={props.actions}
-                      useV2Actions={settings.general.newLayoutDesigns()}
+                      useV2Actions={props.data.newLayoutDesigns()}
                       comments={messageComments()}
                     />
                   </div>
@@ -1210,7 +857,7 @@ export function MessageTimeline(props: {
             <div data-slot="session-turn-message-container" class="w-full px-4 md:px-5">
               <TimelineThinkingRow
                 reasoningHeading={thinkingRow().reasoningHeading}
-                showReasoningSummaries={settings.general.showReasoningSummaries()}
+                showReasoningSummaries={props.data.showReasoningSummaries()}
               />
             </div>
           </TimelineRowFrame>
@@ -1326,16 +973,16 @@ export function MessageTimeline(props: {
       <div
         class="absolute left-1/2 -translate-x-1/2 z-[60] pointer-events-none transition-all duration-200 ease-out"
         classList={{
-          "bottom-8": settings.general.newLayoutDesigns(),
-          "bottom-6": !settings.general.newLayoutDesigns(),
+          "bottom-8": props.data.newLayoutDesigns(),
+          "bottom-6": !props.data.newLayoutDesigns(),
           "opacity-100 translate-y-0 scale-100": props.scroll.overflow && props.scroll.jump,
           "opacity-0 translate-y-2 pointer-events-none": !props.scroll.overflow || !props.scroll.jump,
-          "scale-[0.8]": (!props.scroll.overflow || !props.scroll.jump) && settings.general.newLayoutDesigns(),
-          "scale-95": (!props.scroll.overflow || !props.scroll.jump) && !settings.general.newLayoutDesigns(),
+          "scale-[0.8]": (!props.scroll.overflow || !props.scroll.jump) && props.data.newLayoutDesigns(),
+          "scale-95": (!props.scroll.overflow || !props.scroll.jump) && !props.data.newLayoutDesigns(),
         }}
       >
         <Show
-          when={settings.general.newLayoutDesigns()}
+          when={props.data.newLayoutDesigns()}
           fallback={
             <button
               type="button"
@@ -1398,22 +1045,22 @@ export function MessageTimeline(props: {
             classList={{
               "sticky top-0 z-30": true,
               "bg-[linear-gradient(to_bottom,var(--v2-background-bg-base)_48px,transparent)]":
-                settings.general.newLayoutDesigns(),
+                props.data.newLayoutDesigns(),
               "bg-[linear-gradient(to_bottom,var(--background-stronger)_48px,transparent)]":
-                !settings.general.newLayoutDesigns(),
+                !props.data.newLayoutDesigns(),
               "w-full": true,
               "pb-4": true,
               "pr-3": true,
-              "pl-2.5": settings.general.newLayoutDesigns(),
-              "pl-2 md:pl-4": !settings.general.newLayoutDesigns(),
-              "md:max-w-200 md:mx-auto 2xl:max-w-[1000px]": props.centered && !settings.general.newLayoutDesigns(),
+              "pl-2.5": props.data.newLayoutDesigns(),
+              "pl-2 md:pl-4": !props.data.newLayoutDesigns(),
+              "md:max-w-200 md:mx-auto 2xl:max-w-[1000px]": props.centered && !props.data.newLayoutDesigns(),
             }}
           >
             <div class="h-12 w-full flex items-center justify-between gap-2">
               <div
                 classList={{
                   "flex items-center gap-1 min-w-0 flex-1": true,
-                  "pr-3": !settings.general.newLayoutDesigns(),
+                  "pr-3": !props.data.newLayoutDesigns(),
                 }}
               >
                 <div class="flex items-center min-w-0 flex-1 w-full">
@@ -1422,7 +1069,7 @@ export function MessageTimeline(props: {
                       type="button"
                       data-slot="session-title-parent"
                       class="min-w-0 max-w-[40%] truncate pl-2 text-[13px] font-[530] leading-4 tracking-[-0.04px] text-v2-text-text-faint transition-colors hover:text-v2-text-text-muted"
-                      onClick={navigateParent}
+                      onClick={props.action.navigateParent}
                     >
                       {parentTitle()}
                     </button>
@@ -1443,8 +1090,8 @@ export function MessageTimeline(props: {
                           classList={{
                             "truncate text-[13px] font-[530] leading-4 tracking-[-0.04px] text-v2-text-text-base": true,
                             "w-fit rounded-[6px] px-2 py-1 hover:bg-v2-overlay-simple-overlay-hover":
-                              settings.general.newLayoutDesigns(),
-                            "grow-1 min-w-0": !settings.general.newLayoutDesigns(),
+                              props.data.newLayoutDesigns(),
+                            "grow-1 min-w-0": !props.data.newLayoutDesigns(),
                           }}
                           onClick={openTitleEditor}
                         >
@@ -1458,15 +1105,14 @@ export function MessageTimeline(props: {
                         }}
                         data-slot="session-title-child"
                         value={title.draft}
-                        disabled={titleMutation.isPending}
+                        disabled={props.pending.rename()}
                         classList={{
                           "block text-[13px] font-[530] leading-4 tracking-[-0.04px] text-v2-text-text-base": true,
-                          "w-full flex-1 grow-1 min-w-0 pl-1 -ml-1 rounded-[6px]": !settings.general.newLayoutDesigns(),
-                          "field-sizing-content self-start rounded-[6px] px-2 py-1 ":
-                            settings.general.newLayoutDesigns(),
+                          "w-full flex-1 grow-1 min-w-0 pl-1 -ml-1 rounded-[6px]": !props.data.newLayoutDesigns(),
+                          "field-sizing-content self-start rounded-[6px] px-2 py-1 ": props.data.newLayoutDesigns(),
                         }}
                         style={{
-                          "--inline-input-shadow": settings.general.newLayoutDesigns()
+                          "--inline-input-shadow": props.data.newLayoutDesigns()
                             ? "none"
                             : "var(--shadow-xs-border-select)",
                         }}
@@ -1494,17 +1140,17 @@ export function MessageTimeline(props: {
                   <div
                     classList={{
                       "shrink-0 flex items-center": true,
-                      "gap-2": settings.general.newLayoutDesigns(),
-                      "gap-3": !settings.general.newLayoutDesigns(),
+                      "gap-2": props.data.newLayoutDesigns(),
+                      "gap-3": !props.data.newLayoutDesigns(),
                     }}
                   >
                     <SessionContextUsage
                       placement="bottom"
-                      buttonAppearance={settings.general.newLayoutDesigns() ? "v2" : "default"}
+                      buttonAppearance={props.data.newLayoutDesigns() ? "v2" : "default"}
                     />
                     <Show when={!parentID()}>
                       <Show
-                        when={settings.general.newLayoutDesigns()}
+                        when={props.data.newLayoutDesigns()}
                         fallback={
                           <DropdownMenu
                             gutter={4}
@@ -1567,13 +1213,11 @@ export function MessageTimeline(props: {
                                     </DropdownMenu.ItemLabel>
                                   </DropdownMenu.Item>
                                 </Show>
-                                <DropdownMenu.Item onSelect={() => void archiveSession(id)}>
+                                <DropdownMenu.Item onSelect={() => void props.action.archive(id)}>
                                   <DropdownMenu.ItemLabel>{language.t("common.archive")}</DropdownMenu.ItemLabel>
                                 </DropdownMenu.Item>
                                 <DropdownMenu.Separator />
-                                <DropdownMenu.Item
-                                  onSelect={() => dialog.show(() => <DialogDeleteSession sessionID={id} />)}
-                                >
+                                <DropdownMenu.Item onSelect={() => props.action.showDelete(id)}>
                                   <DropdownMenu.ItemLabel>{language.t("common.delete")}</DropdownMenu.ItemLabel>
                                 </DropdownMenu.Item>
                               </DropdownMenu.Content>
@@ -1638,11 +1282,11 @@ export function MessageTimeline(props: {
                                   {language.t("session.share.action.share")}...
                                 </MenuV2.Item>
                               </Show>
-                              <MenuV2.Item onSelect={() => void archiveSession(id)}>
+                              <MenuV2.Item onSelect={() => void props.action.archive(id)}>
                                 {language.t("common.archive")}
                               </MenuV2.Item>
                               <MenuV2.Separator />
-                              <MenuV2.Item onSelect={() => dialog.show(() => <DialogDeleteSession sessionID={id} />)}>
+                              <MenuV2.Item onSelect={() => props.action.showDelete(id)}>
                                 {language.t("common.delete")}...
                               </MenuV2.Item>
                             </MenuV2.Content>
@@ -1654,7 +1298,7 @@ export function MessageTimeline(props: {
                         open={share.open}
                         anchorRef={() => more}
                         placement="bottom-end"
-                        gutter={settings.general.newLayoutDesigns() ? 6 : 4}
+                        gutter={props.data.newLayoutDesigns() ? 6 : 4}
                         modal={false}
                         onOpenChange={(open) => {
                           if (open) setShare("dismiss", null)
@@ -1666,7 +1310,7 @@ export function MessageTimeline(props: {
                             data-component="popover-content"
                             classList={{
                               "flex w-80 max-w-none flex-col items-start gap-3 rounded-[10px] border-0 bg-v2-background-bg-layer-01 p-3 shadow-[var(--v2-elevation-floating)]":
-                                settings.general.newLayoutDesigns(),
+                                props.data.newLayoutDesigns(),
                             }}
                             style={{ "min-width": "320px" }}
                             onEscapeKeyDown={(event) => {
@@ -1686,7 +1330,7 @@ export function MessageTimeline(props: {
                             }}
                           >
                             <Show
-                              when={settings.general.newLayoutDesigns()}
+                              when={props.data.newLayoutDesigns()}
                               fallback={
                                 <div class="flex flex-col p-3">
                                   <div class="flex flex-col gap-1">
@@ -1707,10 +1351,10 @@ export function MessageTimeline(props: {
                                           size="large"
                                           variant="primary"
                                           class="w-full"
-                                          onClick={shareSession}
-                                          disabled={shareMutation.isPending}
+                                          onClick={() => void props.action.share()}
+                                          disabled={props.pending.share()}
                                         >
-                                          {shareMutation.isPending
+                                          {props.pending.share()
                                             ? language.t("session.share.action.publishing")
                                             : language.t("session.share.action.publish")}
                                         </Button>
@@ -1730,10 +1374,10 @@ export function MessageTimeline(props: {
                                             size="large"
                                             variant="secondary"
                                             class="w-full shadow-none border border-border-weak-base"
-                                            onClick={unshareSession}
-                                            disabled={unshareMutation.isPending}
+                                            onClick={() => void props.action.unshare()}
+                                            disabled={props.pending.unshare()}
                                           >
-                                            {unshareMutation.isPending
+                                            {props.pending.unshare()
                                               ? language.t("session.share.action.unpublishing")
                                               : language.t("session.share.action.unpublish")}
                                           </Button>
@@ -1741,8 +1385,8 @@ export function MessageTimeline(props: {
                                             size="large"
                                             variant="primary"
                                             class="w-full"
-                                            onClick={viewShare}
-                                            disabled={unshareMutation.isPending}
+                                            onClick={props.action.viewShare}
+                                            disabled={props.pending.unshare()}
                                           >
                                             {language.t("session.share.action.view")}
                                           </Button>
@@ -1770,10 +1414,10 @@ export function MessageTimeline(props: {
                                     <ButtonV2
                                       variant="contrast"
                                       class="w-full"
-                                      onClick={shareSession}
-                                      disabled={shareMutation.isPending}
+                                      onClick={() => void props.action.share()}
+                                      disabled={props.pending.share()}
                                     >
-                                      {shareMutation.isPending
+                                      {props.pending.share()
                                         ? language.t("session.share.action.publishing")
                                         : language.t("session.share.action.publish")}
                                     </ButtonV2>
@@ -1799,7 +1443,7 @@ export function MessageTimeline(props: {
                                         variant="ghost-muted"
                                         icon={<IconV2 name="outline-copy" />}
                                         aria-label={language.t("session.share.copy.copyLink")}
-                                        onClick={copyShareUrl}
+                                        onClick={() => void props.action.copyShareUrl()}
                                       />
                                       <IconButtonV2
                                         type="button"
@@ -1807,18 +1451,18 @@ export function MessageTimeline(props: {
                                         variant="ghost-muted"
                                         icon={<IconV2 name="outline-square-arrow" />}
                                         aria-label={language.t("session.share.action.view")}
-                                        onClick={viewShare}
-                                        disabled={unshareMutation.isPending}
+                                        onClick={props.action.viewShare}
+                                        disabled={props.pending.unshare()}
                                       />
                                     </div>
                                     <div class="flex w-full">
                                       <ButtonV2
                                         variant="outline"
                                         class="w-full"
-                                        onClick={unshareSession}
-                                        disabled={unshareMutation.isPending}
+                                        onClick={() => void props.action.unshare()}
+                                        disabled={props.pending.unshare()}
                                       >
-                                        {unshareMutation.isPending
+                                        {props.pending.unshare()
                                           ? language.t("session.share.action.unpublishing")
                                           : language.t("session.share.action.unpublish")}
                                       </ButtonV2>

packages/app/src/pages/session/timeline/model.ts

@@ -1,23 +1,24 @@
-import type { Message, UserMessage } from "@opencode-ai/sdk/v2"
+import type { Message } from "@opencode-ai/sdk/v2"
 import { createMemo, createResource, onCleanup, untrack, type Accessor } from "solid-js"
 import { useServerSync } from "@/context/server-sync"
 import { useSync } from "@/context/sync"
-import { same } from "@/utils/same"
+import type { SessionController } from "../session-controller"
+
+export {
+  selectSessionUserMessages as selectUserMessages,
+  selectVisibleSessionUserMessages as selectVisibleUserMessages,
+} from "../session-domain"
 
-const emptyUserMessages: UserMessage[] = []
 const sessionFreshness = 15_000
 
-export function createTimelineModel(input: {
-  sessionID: Accessor<string | undefined>
-  revertMessageID: Accessor<string | undefined>
-}) {
+export function createTimelineModel(input: { session: Pick<SessionController, "identity" | "history"> }) {
   const serverSync = useServerSync()
   const sync = useSync()
   let refreshFrame: number | undefined
   let refreshTimer: number | undefined
 
   const [resource] = createResource(
-    () => input.sessionID(),
+    () => input.session.identity.sessionID(),
     (id) => {
       clearRefresh()
       if (!id) return
@@ -29,7 +30,7 @@ export function createTimelineModel(input: {
         refreshFrame = undefined
         refreshTimer = window.setTimeout(() => {
           refreshTimer = undefined
-          if (input.sessionID() !== id) return
+          if (input.session.identity.sessionID() !== id) return
           untrack(() => {
             if (stale) void sync().session.sync(id, { force: true })
           })
@@ -39,33 +40,21 @@ export function createTimelineModel(input: {
       return sync().session.sync(id)
     },
   )
-  const messages = createMemo(() => {
-    const id = input.sessionID()
-    return id ? (sync().data.message[id] ?? []) : []
-  })
   const ready = createMemo(() => {
-    const id = input.sessionID()
+    const id = input.session.identity.sessionID()
     return !id || isTimelineReady(sync().data.message[id], serverSync().session.history.loading(id))
   })
-  const userMessages = createMemo(() => selectUserMessages(messages()), emptyUserMessages, { equals: same })
-  const visibleUserMessages = createMemo(
-    () => {
-      return selectVisibleUserMessages(userMessages(), input.revertMessageID())
-    },
-    emptyUserMessages,
-    { equals: same },
-  )
   const more = createMemo(() => {
-    const id = input.sessionID()
+    const id = input.session.identity.sessionID()
     return id ? sync().session.history.more(id) : false
   })
   const loading = createMemo(() => {
-    const id = input.sessionID()
+    const id = input.session.identity.sessionID()
     return id ? sync().session.history.loading(id) : false
   })
   const loadOlder = async (options?: { before?: () => void; after?: (done: boolean) => void }) => {
     return loadOlderTimeline({
-      sessionID: input.sessionID,
+      sessionID: input.session.identity.sessionID,
       more,
       loading,
       loadMore: (sessionID) => sync().session.history.loadMore(sessionID),
@@ -78,12 +67,12 @@ export function createTimelineModel(input: {
 
   return {
     history: { loadOlder, loading, more },
-    lastUserMessage: createMemo(() => visibleUserMessages().at(-1)),
-    messages,
+    lastUserMessage: input.session.history.lastUserMessage,
+    messages: input.session.history.messages,
     ready,
     resource,
-    userMessages,
-    visibleUserMessages,
+    userMessages: input.session.history.userMessages,
+    visibleUserMessages: input.session.history.visibleUserMessages,
   }
 
   function clearRefresh() {
@@ -94,19 +83,10 @@ export function createTimelineModel(input: {
   }
 }
 
-export function selectUserMessages(messages: Message[]) {
-  return messages.filter((message): message is UserMessage => message.role === "user")
-}
-
 export function isTimelineReady(messages: Message[] | undefined, loading: boolean) {
   return messages !== undefined && (messages.some((message) => message.role === "user") || !loading)
 }
 
-export function selectVisibleUserMessages(messages: UserMessage[], revertMessageID?: string) {
-  if (!revertMessageID) return messages
-  return messages.filter((message) => message.id < revertMessageID)
-}
-
 export async function loadOlderTimeline(input: {
   sessionID: Accessor<string | undefined>
   more: Accessor<boolean>

packages/app/src/pages/session/use-session-commands.tsx

@@ -13,19 +13,25 @@ import { useSync } from "@/context/sync"
 import { useTerminal } from "@/context/terminal"
 import { showToast } from "@/utils/toast"
 import { findLast } from "@opencode-ai/core/util/array"
-import { createSessionTabs } from "@/pages/session/helpers"
 import { extractPromptFromParts } from "@/utils/prompt"
-import { UserMessage } from "@opencode-ai/sdk/v2"
-import { useSessionLayout } from "@/pages/session/session-layout"
-import { createSessionOwnership } from "./session-ownership"
+import type { UserMessage } from "@opencode-ai/sdk/v2"
 import { useLocal } from "@/context/local"
+import type { SessionController } from "./session-controller"
+
+type SessionCommandSource = {
+  identity: SessionController["identity"]
+  data: Pick<SessionController["data"], "info" | "revertMessageID">
+  history: Pick<SessionController["history"], "userMessages" | "visibleUserMessages">
+  layout: SessionController["layout"]
+  ownership: SessionController["ownership"]
+  tabs: Pick<SessionController["tabs"], "activeFileTab" | "closableTab">
+}
 
 export type SessionCommandContext = {
+  session: SessionCommandSource
   navigateMessageByOffset: (offset: number) => void
   setActiveMessage: (message: UserMessage | undefined) => void
   focusInput: () => void
-  review?: () => boolean
-  fileBrowser?: () => boolean
 }
 
 const withCategory = (category: string) => {
@@ -49,15 +55,17 @@ export const useSessionCommands = (actions: SessionCommandContext) => {
   const layout = useLayout()
   const local = useLocal()
   const navigate = useNavigate()
-  const { params, sessionKey, tabs, view } = useSessionLayout()
-  const sessionOwnership = createSessionOwnership(sessionKey)
+  const params = actions.session.identity.params
+  const tabs = actions.session.layout.tabs
+  const view = actions.session.layout.view
+  const sessionOwnership = actions.session.ownership
   const openDialog = async <T,>(load: () => Promise<T>, show: (value: T) => void) => {
     const owner = sessionOwnership.capture()
     const value = await load()
     owner.run(() => show(value))
   }
   const runCommand = async <T,>(input: {
-    owner: ReturnType<ReturnType<typeof createSessionOwnership>["capture"]>
+    owner: ReturnType<SessionController["ownership"]["capture"]>
     prompt: T
     request: () => Promise<unknown>
     updatePrompt: (prompt: T) => void
@@ -68,39 +76,13 @@ export const useSessionCommands = (actions: SessionCommandContext) => {
     input.owner.run(input.updateViewport)
   }
 
-  const info = () => {
-    const id = params.id
-    if (!id) return
-    return sync().session.get(id)
-  }
-  const hasReview = () => !!params.id
-  const normalizeTab = (tab: string) => {
-    if (!tab.startsWith("file://")) return tab
-    return file.tab(tab)
-  }
-  const tabState = createSessionTabs({
-    tabs,
-    pathFromTab: file.pathFromTab,
-    normalizeTab,
-    review: actions.review,
-    hasReview,
-    fileBrowser: actions.fileBrowser,
-  })
-  const activeFileTab = tabState.activeFileTab
-  const closableTab = tabState.closableTab
+  const info = actions.session.data.info
+  const activeFileTab = actions.session.tabs.activeFileTab
+  const closableTab = actions.session.tabs.closableTab
   const shown = settings.visibility.fileTree
 
-  const messages = () => {
-    const id = params.id
-    if (!id) return []
-    return sync().data.message[id] ?? []
-  }
-  const userMessages = () => messages().filter((m) => m.role === "user") as UserMessage[]
-  const visibleUserMessages = () => {
-    const revert = info()?.revert?.messageID
-    if (!revert) return userMessages()
-    return userMessages().filter((m) => m.id < revert)
-  }
+  const userMessages = actions.session.history.userMessages
+  const visibleUserMessages = actions.session.history.visibleUserMessages
 
   const showAllFiles = () => {
     if (layout.fileTree.tab() !== "changes") return
@@ -309,7 +291,7 @@ export const useSessionCommands = (actions: SessionCommandContext) => {
     const session = sdk().api.session
     const directory = sdk().directory
     const promptSession = prompt.capture()
-    const revert = info()?.revert?.messageID
+    const revert = actions.session.data.revertMessageID()
     const messages = userMessages()
     const message = findLast(messages, (x) => !revert || x.id < revert)
     if (!message) return
@@ -338,7 +320,7 @@ export const useSessionCommands = (actions: SessionCommandContext) => {
     const messages = userMessages()
     const promptSession = prompt.capture()
 
-    const revertMessageID = info()?.revert?.messageID
+    const revertMessageID = actions.session.data.revertMessageID()
     if (!revertMessageID) return
 
     const next = messages.find((x) => x.id > revertMessageID)

packages/app/src/utils/server-compat.test.ts

@@ -26,6 +26,7 @@ function setup(
         return new Response(undefined, { status: 204 })
       if (request.method === "POST" && request.url.endsWith("/prompt")) {
         return Response.json({
+          admittedSeq: 1,
           id: "msg_1",
           sessionID: "ses_1",
           timeCreated: 1,

packages/app/src/utils/server-compat.ts

@@ -229,6 +229,7 @@ function createV1Api(input: CompatibleInput): CompatibleApi {
           ],
         })
         return {
+          admittedSeq: 0,
           id: value.id ?? "",
           sessionID: value.sessionID,
           timeCreated: Date.now(),
@@ -254,6 +255,7 @@ function createV1Api(input: CompatibleInput): CompatibleApi {
           })),
         })
         return {
+          admittedSeq: 0,
           id: value.id ?? "",
           sessionID: value.sessionID,
           timeCreated: Date.now(),
@@ -278,6 +280,7 @@ function createV1Api(input: CompatibleInput): CompatibleApi {
           modelID: value.model.modelID,
         })
         return {
+          admittedSeq: 0,
           id: value.id ?? "",
           sessionID: value.sessionID,
           timeCreated: Date.now(),

packages/cli/src/acp/service.ts

@@ -244,10 +244,7 @@ export function make(input: { readonly client: OpenCodeClient; readonly connecti
       return {}
     },
     forkSession: async (params) => {
-      const forked = await input.client.session.fork({
-        sessionID: params.sessionId,
-        boundary: { type: "through" },
-      })
+      const forked = await input.client.session.fork({ sessionID: params.sessionId })
       const state = await attach(forked, forked.location.directory, params.mcpServers ?? [])
       await replay(state)
       return { sessionId: state.id, configOptions: configOptions(state) }

packages/cli/src/session-target.ts

@@ -105,7 +105,7 @@ async function selectSession(input: {
     return {
       session: input.fork
         ? await input.client.session
-            .fork({ sessionID: explicit.id, boundary: { type: "through" } }, ...requestOptions(input.signal))
+            .fork({ sessionID: explicit.id }, ...requestOptions(input.signal))
             .catch((error) => {
               throw new SessionTargetMutationError(error)
             })
@@ -118,11 +118,9 @@ async function selectSession(input: {
   if (!selected) return { session: undefined, location }
   return {
     session: input.fork
-      ? await input.client.session
-          .fork({ sessionID: selected.id, boundary: { type: "through" } }, ...requestOptions(input.signal))
-          .catch((error) => {
-            throw new SessionTargetMutationError(error)
-          })
+      ? await input.client.session.fork({ sessionID: selected.id }, ...requestOptions(input.signal)).catch((error) => {
+          throw new SessionTargetMutationError(error)
+        })
       : selected,
   }
 }

packages/cli/test/acp/service-lifecycle.test.ts

@@ -136,7 +136,7 @@ describe("acp service lifecycle", () => {
       method: "POST",
       path: "/api/session/ses_loaded/fork",
       query: {},
-      body: { boundary: { type: "through" } },
+      body: {},
     })
   })
 

packages/cli/test/run/noninteractive.test.ts

@@ -267,7 +267,7 @@ async function run(input: {
     values.push(...input.turn(messageID))
     wake?.()
     wake = undefined
-    return ok({ id: messageID, sessionID: "ses_1", timeCreated: 1 }) as never
+    return ok({ admittedSeq: 1, id: messageID, sessionID: "ses_1", timeCreated: 1 }) as never
   })
   await runNonInteractivePrompt({
     client: sdk,

packages/client/src/effect/api/api.ts

@@ -136,7 +136,7 @@ export type Endpoint5_4Input = { readonly sessionID: Session.ID }
 export type Endpoint5_4Output = void
 export type SessionRemoveOperation<E = never> = (input: Endpoint5_4Input) => Effect.Effect<Endpoint5_4Output, E>
 
-export type Endpoint5_5Input = { readonly sessionID: Session.ID; readonly boundary: Session.ForkRequestBoundary }
+export type Endpoint5_5Input = { readonly sessionID: Session.ID; readonly messageID?: SessionMessage.ID | undefined }
 export type Endpoint5_5Output = Session.Info
 export type SessionForkOperation<E = never> = (input: Endpoint5_5Input) => Effect.Effect<Endpoint5_5Output, E>
 
@@ -342,10 +342,8 @@ export type Endpoint5_26Output =
           readonly data: {
             readonly sessionID: Session.ID
             readonly parentID: Session.ID
-            readonly boundary: Session.ForkBoundary
-            readonly instructions?:
-              | { readonly [x: string & Brand.Brand<"Instruction.Key">]: string & Brand.Brand<"Instruction.Hash"> }
-              | undefined
+            readonly parentSeq: number
+            readonly from?: SessionMessage.ID | undefined
           }
         }
       | {

packages/client/src/effect/generated/client.ts

@@ -329,7 +329,7 @@ const Endpoint5_4 = (raw: RawClient["server.session"]) => (input: Endpoint5_4Inp
 
 const Endpoint5_5 = (raw: RawClient["server.session"]) => (input: Endpoint5_5Input) =>
   preserveEffect<Endpoint5_5Output>()(
-    raw["session.fork"]({ params: { sessionID: input["sessionID"] }, payload: { boundary: input["boundary"] } }).pipe(
+    raw["session.fork"]({ params: { sessionID: input["sessionID"] }, payload: { messageID: input["messageID"] } }).pipe(
       Effect.mapError(mapClientError),
       Effect.map((value) => value.data),
     ),

packages/client/src/promise/generated/client.ts

@@ -510,7 +510,7 @@ export function make(options: ClientOptions) {
           {
             method: "POST",
             path: `/api/session/${encodeURIComponent(input.sessionID)}/fork`,
-            body: { boundary: input["boundary"] },
+            body: { messageID: input["messageID"] },
             successStatus: 200,
             declaredStatuses: [404, 400, 401],
             empty: false,

packages/client/src/promise/generated/types.ts

@@ -14,8 +14,6 @@ export type PermissionEffect = "allow" | "deny" | "ask"
 
 export type PluginInfo = { id: string }
 
-export type SessionForkBoundary = { type: "before"; messageID: string } | { type: "through"; messageID: string }
-
 export type MoneyUSD = number
 
 export type TokenUsageInfo = {
@@ -45,7 +43,13 @@ export type PromptMention = { start: number; end: number; text: string }
 
 export type SessionPendingSyntheticData = { text: string; description?: string; metadata?: { [x: string]: JsonValue } }
 
-export type SessionPendingCompaction = { id: string; sessionID: string; timeCreated: number; type: "compaction" }
+export type SessionPendingCompaction = {
+  admittedSeq: number
+  id: string
+  sessionID: string
+  timeCreated: number
+  type: "compaction"
+}
 
 export type SessionMessageAgentSelected = {
   id: string
@@ -624,7 +628,7 @@ export type SessionForked = {
   type: "session.forked"
   durable: { aggregateID: string; seq: number; version: 2 }
   location?: LocationRef
-  data: { sessionID: string; parentID: string; boundary: SessionForkBoundary; instructions?: { [x: string]: string } }
+  data: { sessionID: string; parentID: string; parentSeq: number; from?: string }
 }
 
 export type SessionInputPromoted = {
@@ -1206,6 +1210,7 @@ export type PromptFileAttachment = {
 export type PromptAgentAttachment = { name: string; mention?: PromptMention }
 
 export type SessionPendingSynthetic = {
+  admittedSeq: number
   id: string
   sessionID: string
   timeCreated: number
@@ -1750,7 +1755,7 @@ export type PermissionRuleset = Array<PermissionRule>
 export type SessionInfo = {
   id: string
   parentID?: string
-  fork?: { sessionID: string; boundary: SessionForkBoundary }
+  fork?: { sessionID: string; messageID?: string }
   projectID: string
   agent?: string
   model?: ModelRef
@@ -1961,6 +1966,7 @@ export type AgentInfo = {
 export type SessionsResponse = { data: Array<SessionInfo>; cursor: { previous?: string | null; next?: string | null } }
 
 export type SessionPendingUser = {
+  admittedSeq: number
   id: string
   sessionID: string
   timeCreated: number
@@ -2696,9 +2702,7 @@ export type SessionRemoveOutput = void
 
 export type SessionForkInput = {
   readonly sessionID: { readonly sessionID: string }["sessionID"]
-  readonly boundary: {
-    readonly boundary: { readonly type: "before"; readonly messageID: string } | { readonly type: "through" }
-  }["boundary"]
+  readonly messageID?: { readonly messageID?: string | undefined }["messageID"]
 }
 
 export type SessionForkOutput = { data: SessionInfo }["data"]

packages/client/test/effect.test.ts

@@ -268,6 +268,7 @@ const session = {
 
 const admission = {
   data: {
+    admittedSeq: 0,
     id: "msg_test",
     sessionID: "ses_test",
     type: "user",
@@ -280,6 +281,7 @@ const admission = {
 const compactionAdmission = {
   data: {
     type: "compaction",
+    admittedSeq: 1,
     id: "msg_compaction",
     sessionID: "ses_test",
     timeCreated: 1_717_171_717_000,

packages/client/test/promise.test.ts

@@ -304,6 +304,7 @@ test("session.pending.list uses the public HTTP contract", async () => {
   const requests: Array<{ method: string; url: string }> = []
   const pending = [
     {
+      admittedSeq: 3,
       id: "msg_pending",
       sessionID: "ses_test",
       timeCreated: 1_717_171_717_000,
@@ -546,6 +547,7 @@ const session = {
 
 const admission = {
   data: {
+    admittedSeq: 0,
     id: "msg_test",
     sessionID: "ses_test",
     type: "user",
@@ -557,6 +559,7 @@ const admission = {
 
 const syntheticAdmission = {
   data: {
+    admittedSeq: 1,
     id: "msg_synthetic",
     sessionID: "ses_test",
     type: "synthetic",
@@ -569,6 +572,7 @@ const syntheticAdmission = {
 const compactionAdmission = {
   data: {
     type: "compaction",
+    admittedSeq: 1,
     id: "msg_compaction",
     sessionID: "ses_test",
     timeCreated: 1_717_171_717_000,

packages/core/schema.json

@@ -1,9 +1,9 @@
 {
   "version": "7",
   "dialect": "sqlite",
-  "id": "db37a97f-9b5e-4c87-be8b-4feace35136c",
+  "id": "a4ba73b4-21bc-41ab-a415-94e2ca38d798",
   "prevIds": [
-    "a4ba73b4-21bc-41ab-a415-94e2ca38d798"
+    "5f0a1db8-d4bf-42c3-becb-96b46fe66bed"
   ],
   "ddl": [
     {
@@ -1266,7 +1266,17 @@
       "autoincrement": false,
       "default": null,
       "generated": null,
-      "name": "fork_boundary",
+      "name": "fork_message_id",
+      "entityType": "columns",
+      "table": "session"
+    },
+    {
+      "type": "integer",
+      "notNull": false,
+      "autoincrement": false,
+      "default": null,
+      "generated": null,
+      "name": "fork_seq",
       "entityType": "columns",
       "table": "session"
     },

packages/core/src/codemode/catalog.ts

@@ -6,7 +6,6 @@ export const Entry = Schema.Struct({
   path: Schema.String,
   description: Schema.String,
   signature: Schema.String,
-  pinned: Schema.optionalKey(Schema.Boolean),
 })
 export type Entry = typeof Entry.Type
 
@@ -57,39 +56,26 @@ export function summarize(entries: ReadonlyArray<Entry>, budget = INLINE_BUDGET)
           if (left.path > right.path) return 1
           return 0
         })
-      const ranked = rankListings(listings)
-      const pinned = new Set(
-        namespaceEntries
-          .filter((entry) => entry.pinned)
-          .map((entry) => listings.find((listing) => listing.path === entry.path))
-          .filter((listing) => listing !== undefined),
-      )
       return {
         name,
         listings,
-        selectionOrder: ranked.filter((candidate) => !pinned.has(candidate.listing)),
-        selectedListings: pinned,
-        selectionIndex: 0,
+        selectionOrder: rankListings(listings),
+        selectedListings: new Set<typeof Listing.Type>(),
       }
     })
 
   const active = new Set(namespaces)
-  let remaining =
-    budget -
-    namespaces
-      .flatMap((namespace) => namespace.listings.filter((listing) => namespace.selectedListings.has(listing)))
-      .reduce((total, listing) => total + Math.round(listing.line.length / CHARACTERS_PER_TOKEN), 0)
+  let remaining = budget
   while (active.size > 0) {
     for (const namespace of active) {
-      const candidate = namespace.selectionOrder[namespace.selectionIndex]
+      const candidate = namespace.selectionOrder[namespace.selectedListings.size]
       if (!candidate || candidate.cost > remaining) {
         active.delete(namespace)
         continue
       }
       namespace.selectedListings.add(candidate.listing)
-      namespace.selectionIndex += 1
       remaining -= candidate.cost
-      if (namespace.selectionIndex === namespace.selectionOrder.length) active.delete(namespace)
+      if (namespace.selectedListings.size === namespace.selectionOrder.length) active.delete(namespace)
     }
   }
 

packages/core/src/codemode/instructions.ts

@@ -6,9 +6,7 @@ import { Instructions } from "../instructions/index"
 import { CodeModeCatalog } from "./catalog"
 
 // prettier-ignore
-const prompt = (hasMoreTools: boolean) => `The Code Mode tool catalog below is ${hasMoreTools ? "partial" : "complete"}.
-
-${hasMoreTools ? "The Code Mode catalog and `search` results are" : "This catalog is"} the complete set of tools available within Code Mode. Tools presented elsewhere are not available in this runtime.${hasMoreTools ? `
+const prompt = (hasMoreTools: boolean) => `The Code Mode tool catalog below is ${hasMoreTools ? "partial" : "complete"}.${hasMoreTools ? `
 
 ## Search
 

packages/core/src/codemode/tool.ts

@@ -33,7 +33,7 @@ type CollectedFiles = {
 
 // Invariant model-facing guidance; the changing tool catalog is delivered through Instructions.
 const description = [
-  "Run JavaScript in a confined Code Mode runtime to orchestrate tool calls and compose their results.",
+  "Run JavaScript to orchestrate tool calls and compose their results through `{ code }` in a confined Code Mode runtime.",
   "Imports, direct filesystem access, and timers are unavailable. Do not use `fetch`; all external access goes through `tools`.",
   "Within `{ code }`, the only callable tools are those explicitly listed in the Code Mode catalog instructions or returned by `search`. Inside `{ code }`, ignore tools shown outside the Code Mode catalog. They are not available in the Code Mode runtime.",
   'Call tools through `tools` using only exact paths and signatures from the catalog. Do not infer or normalize tool names; preserve bracket notation such as `tools.<namespace>["tool-name"](input)`.',
@@ -138,14 +138,7 @@ export const create = (
 }
 
 export const catalog = (registrations: ReadonlyMap<string, Info>) => {
-  const pinned = new Set(
-    Array.from(registrations.values())
-      .filter((registration) => registration.options?.pinned === true)
-      .map(qualifiedName),
-  )
-  return runtime(registrations, () => Effect.fail(toolError("Execute context is unavailable")))
-    .catalog()
-    .map((entry) => ({ ...entry, pinned: pinned.has(entry.path) }))
+  return runtime(registrations, () => Effect.fail(toolError("Execute context is unavailable"))).catalog()
 }
 
 function runtime(
@@ -156,7 +149,11 @@ function runtime(
   const tools: Record<string, Tool.Tool<never>> = {}
   for (const [name, registration] of registrations) {
     const child = definition(registration)
-    const path = qualifiedName(registration)
+    const normalized = registration.name.replace(/[^a-zA-Z0-9_-]/g, "_")
+    const path =
+      registration.options?.namespace === undefined
+        ? normalized
+        : `${registration.options.namespace}.${normalized}`
     tools[path] = Tool.make({
       description: child.description,
       input: child.inputSchema,
@@ -167,12 +164,6 @@ function runtime(
   return CodeMode.make<typeof tools>({ tools, ...hooks })
 }
 
-function qualifiedName(registration: Info) {
-  const normalized = registration.name.replace(/[^a-zA-Z0-9_-]/g, "_")
-  if (registration.options?.namespace === undefined) return normalized
-  return `${registration.options.namespace}.${normalized}`
-}
-
 // Tool inputs arrive as parsed JSON, so the JSON value cast is a boundary fact.
 function displayInput(input: unknown): Record<string, typeof Schema.Json.Type> | undefined {
   if (input === null || input === undefined) return

packages/core/src/config.ts

@@ -393,8 +393,7 @@ export const layer = (options?: Options) => Layer.effect(
         const key = JSON.stringify(target)
         if (watched.has(key)) continue
         watched.add(key)
-        const stream = yield* watcher.subscribe(target)
-        yield* stream.pipe(
+        yield* watcher.subscribe(target).pipe(
           Stream.runForEach((update) => PubSub.publish(updates, update)),
           Effect.forkScoped({ startImmediately: true }),
         )

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

@@ -57,6 +57,5 @@ export const migrations = (
     import("./migration/20260716020354_kv"),
     import("./migration/20260722011141_delete_tool_progress_events"),
     import("./migration/20260722170000_canonical_tool_results"),
-    import("./migration/20260729022634_session_fork_boundary"),
   ])
 ).map((module) => module.default) satisfies DatabaseMigration.Migration[]

packages/core/src/database/migration/20260729022634_session_fork_boundary.ts

@@ -1,13 +0,0 @@
-import { Effect } from "effect"
-import type { DatabaseMigration } from "../migration"
-
-export default {
-  id: "20260729022634_session_fork_boundary",
-  up(tx) {
-    return Effect.gen(function* () {
-      yield* tx.run(`ALTER TABLE \`session\` ADD \`fork_boundary\` text;`)
-      yield* tx.run(`ALTER TABLE \`session\` DROP COLUMN \`fork_message_id\`;`)
-      yield* tx.run(`ALTER TABLE \`session\` DROP COLUMN \`fork_seq\`;`)
-    })
-  },
-} satisfies DatabaseMigration.Migration

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

@@ -213,7 +213,8 @@ export default {
           \`workspace_id\` text,
           \`parent_id\` text,
           \`fork_session_id\` text,
-          \`fork_boundary\` text,
+          \`fork_message_id\` text,
+          \`fork_seq\` integer,
           \`slug\` text NOT NULL,
           \`directory\` text NOT NULL,
           \`path\` text,

packages/core/src/file-mutation.ts

@@ -5,7 +5,6 @@ import { Context, Effect, Layer, Schema } from "effect"
 import { dirname } from "path"
 import { KeyedMutex } from "./effect/keyed-mutex"
 import { FSUtil } from "@opencode-ai/util/fs-util"
-import { Bom } from "@opencode-ai/util/bom"
 
 export interface Target {
   readonly canonical: string
@@ -109,13 +108,13 @@ const layer = Layer.effect(
     const writeTextPreservingBom = Effect.fn("FileMutation.writeTextPreservingBom")((input: TextWriteInput) =>
       withTargetLock(input.target)(
         Effect.gen(function* () {
-          const next = Bom.split(input.content)
+          const next = splitBom(input.content)
           const current = yield* fs
             .readFile(input.target.canonical)
             .pipe(Effect.catchReason("PlatformError", "NotFound", () => Effect.succeed(undefined)))
           yield* fs.writeWithDirs(
             input.target.canonical,
-            Bom.join(next.text, Boolean(current && Bom.has(current)) || next.bom),
+            joinBom(next.text, Boolean(current && hasUtf8Bom(current)) || next.bom),
           )
           return writeResult(input.target, current !== undefined)
         }),
@@ -173,6 +172,20 @@ const layer = Layer.effect(
   }),
 )
 
+function splitBom(text: string) {
+  const stripped = text.replace(/^\uFEFF+/, "")
+  return { bom: stripped.length !== text.length, text: stripped }
+}
+
+function joinBom(text: string, bom: boolean) {
+  const stripped = splitBom(text).text
+  return bom ? `\uFEFF${stripped}` : stripped
+}
+
+function hasUtf8Bom(content: Uint8Array) {
+  return content[0] === 0xef && content[1] === 0xbb && content[2] === 0xbf
+}
+
 function sameBytes(left: Uint8Array, right: Uint8Array) {
   if (left.length !== right.length) return false
   return left.every((byte, index) => byte === right[index])

packages/core/src/filesystem/location-watcher.ts

@@ -47,12 +47,13 @@ const layer = Layer.effect(
       const home = path.resolve(location.directory) === path.resolve(os.homedir())
 
       if (!home && location.vcs) {
-        const updates = yield* watcher.subscribe({
-          path: location.directory,
-          type: "directory",
-          ignore: [...Ignore.PATTERNS, ...config, ...protecteds(location.directory)],
-        })
-        yield* updates.pipe(Stream.runForEach(publish), Effect.forkScoped)
+        yield* watcher
+          .subscribe({
+            path: location.directory,
+            type: "directory",
+            ignore: [...Ignore.PATTERNS, ...config, ...protecteds(location.directory)],
+          })
+          .pipe(Stream.runForEach(publish), Effect.forkScoped)
       }
       if (home) {
         yield* Effect.logInfo("location watcher skipped home directory", { directory: location.directory })
@@ -67,8 +68,9 @@ const layer = Layer.effect(
           const ignore = (yield* fs.readDirectoryEntries(vcs).pipe(Effect.catch(() => Effect.succeed([])))).flatMap(
             (entry) => (entry.name === "HEAD" ? [] : [entry.name]),
           )
-          const updates = yield* watcher.subscribe({ path: vcs, type: "directory", ignore })
-          yield* updates.pipe(Stream.runForEach(publish), Effect.forkScoped)
+          yield* watcher
+            .subscribe({ path: vcs, type: "directory", ignore })
+            .pipe(Stream.runForEach(publish), Effect.forkScoped)
         }
       }
     }).pipe(

packages/core/src/filesystem/watcher.ts

@@ -59,7 +59,7 @@ export interface NativeInterface {
 export class Native extends Context.Service<Native, NativeInterface>()("@opencode/Watcher/Native") {}
 
 export interface Interface {
-  readonly subscribe: (input: WatchInput) => Effect.Effect<Stream.Stream<Update>>
+  readonly subscribe: (input: WatchInput) => Stream.Stream<Update>
 }
 
 export const Options = Schema.Struct({
@@ -83,7 +83,7 @@ export const layer = (options?: Options) =>
     Service,
     Effect.gen(function* () {
       if (options?.enabled === false) {
-        return Service.of({ subscribe: () => Effect.succeed(Stream.empty) })
+        return Service.of({ subscribe: () => Stream.empty })
       }
       const native = yield* Native
 
@@ -131,19 +131,11 @@ export const layer = (options?: Options) =>
       const subscribe = (input: WatchInput) => {
         const target = path.resolve(input.path)
         const ignore = [...new Set(input.type === "directory" ? (input.ignore ?? []) : [])].toSorted()
-        return Effect.gen(function* () {
-          yield* Effect.logInfo("watcher subscribe", {
-            path: target,
-            type: input.type,
-            ignores: ignore.length,
-          })
-          return Stream.unwrap(
-            Effect.gen(function* () {
-              const pubsub = yield* RcMap.get(watchers, { type: input.type, target, ignore })
-              return Stream.fromPubSub(pubsub)
-            }),
-          )
-        })
+        return Stream.unwrap(
+          RcMap.get(watchers, { type: input.type, target, ignore }).pipe(
+            Effect.map((pubsub) => Stream.fromPubSub(pubsub)),
+          ),
+        )
       }
 
       return Service.of({ subscribe })

packages/core/src/formatter.ts

@@ -1,157 +0,0 @@
-export * as Formatter from "./formatter"
-
-import { Context, Effect, Layer, Schema } from "effect"
-import { ChildProcess } from "effect/unstable/process"
-import path from "path"
-import { makeLocationNode } from "@opencode-ai/util/effect/app-node"
-import { FSUtil } from "@opencode-ai/util/fs-util"
-import { Npm } from "@opencode-ai/util/npm"
-import { AppProcess } from "@opencode-ai/util/process"
-import { Config } from "./config"
-import { Location } from "./location"
-import { make, type Info } from "./formatter/builtins"
-
-export const Status = Schema.Struct({
-  name: Schema.String,
-  extensions: Schema.Array(Schema.String),
-  enabled: Schema.Boolean,
-}).annotate({ identifier: "FormatterStatus" })
-export type Status = typeof Status.Type
-
-export interface Interface {
-  readonly init: () => Effect.Effect<void>
-  readonly status: () => Effect.Effect<Status[]>
-  readonly file: (filepath: string) => Effect.Effect<boolean>
-}
-
-export class Service extends Context.Service<Service, Interface>()("@opencode/v2/Formatter") {}
-
-const layer = Layer.effect(
-  Service,
-  Effect.gen(function* () {
-    const config = yield* Config.Service
-    const fs = yield* FSUtil.Service
-    const location = yield* Location.Service
-    const npm = yield* Npm.Service
-    const processes = yield* AppProcess.Service
-    const commands = new Map<string, string[] | false>()
-    let formatters: Info[] = []
-
-    const load = yield* Effect.cached(
-      Effect.gen(function* () {
-        const configured = Config.latest(yield* config.entries(), "formatter")
-        if (!configured) {
-          yield* Effect.logInfo("all formatters are disabled")
-          return
-        }
-
-        const builtIns = make({
-          directory: location.directory,
-          worktree: location.project.directory,
-          fs,
-          npm,
-          processes,
-        })
-        formatters = builtIns
-        if (configured === true) return
-        if (configured.ruff?.disabled || configured.uv?.disabled) {
-          formatters = formatters.filter((formatter) => formatter.name !== "ruff" && formatter.name !== "uv")
-        }
-
-        for (const [name, entry] of Object.entries(configured)) {
-          const index = formatters.findIndex((formatter) => formatter.name === name)
-          if (entry.disabled) {
-            if (index !== -1) formatters.splice(index, 1)
-            continue
-          }
-
-          const builtIn = builtIns.find((formatter) => formatter.name === name)
-          const formatter: Info = {
-            name,
-            extensions: entry.extensions ?? builtIn?.extensions ?? [],
-            environment: { ...builtIn?.environment, ...entry.environment },
-            enabled:
-              builtIn && !entry.command ? builtIn.enabled : Effect.succeed(entry.command ? [...entry.command] : false),
-          }
-          if (index === -1) formatters.push(formatter)
-          else formatters[index] = formatter
-        }
-      }).pipe(Effect.withSpan("Formatter.load")),
-    )
-
-    const command = Effect.fnUntraced(function* (formatter: Info) {
-      const cached = commands.get(formatter.name)
-      if (cached !== undefined) return cached
-      const result = yield* formatter.enabled
-      if (result !== false) commands.set(formatter.name, result)
-      return result
-    })
-
-    const init = Effect.fn("Formatter.init")(function* () {
-      yield* load
-    })
-
-    const status = Effect.fn("Formatter.status")(function* () {
-      yield* load
-      return yield* Effect.forEach(formatters, (formatter) =>
-        command(formatter).pipe(
-          Effect.map((enabled) => ({
-            name: formatter.name,
-            extensions: [...formatter.extensions],
-            enabled: enabled !== false,
-          })),
-        ),
-      )
-    })
-
-    const file = Effect.fn("Formatter.file")(function* (filepath: string) {
-      yield* load
-      const matching = formatters.filter((formatter) =>
-        formatter.extensions.includes(path.extname(filepath)),
-      )
-
-      for (const formatter of matching) {
-        const enabled = yield* command(formatter)
-        if (enabled === false) continue
-        const cmd = enabled.map((argument) => argument.replace("$FILE", filepath))
-        yield* Effect.logInfo("formatting file", { file: filepath, command: cmd })
-        const result = yield* processes
-          .run(
-            ChildProcess.make(cmd[0], cmd.slice(1), {
-              cwd: location.directory,
-              env: formatter.environment,
-              extendEnv: true,
-              stdin: "ignore",
-              stdout: "ignore",
-              stderr: "ignore",
-            }),
-          )
-          .pipe(
-            Effect.catch((error) =>
-              Effect.logError("failed to format file", {
-                file: filepath,
-                command: cmd,
-                error: error.message,
-              }).pipe(Effect.as(undefined)),
-            ),
-          )
-        if (!result) continue
-        if (result.exitCode === 0) return true
-        yield* Effect.logError("formatter exited unsuccessfully", {
-          file: filepath,
-          command: cmd,
-          exitCode: result.exitCode,
-        })
-      }
-      return false
-    })
-
-    return Service.of({ init, status, file })
-  }),
-)
-
-export const node = makeLocationNode({
-  service: Service,
-  layer,
-  deps: [Config.node, FSUtil.node, Location.node, Npm.node, AppProcess.node],
-})

packages/core/src/formatter/builtins.ts

@@ -1,315 +0,0 @@
-import { Effect } from "effect"
-import { ChildProcess } from "effect/unstable/process"
-import { FSUtil } from "@opencode-ai/util/fs-util"
-import { Npm } from "@opencode-ai/util/npm"
-import { AppProcess } from "@opencode-ai/util/process"
-import { which } from "../util/which"
-
-export interface Info {
-  readonly name: string
-  readonly environment?: Record<string, string>
-  readonly extensions: readonly string[]
-  readonly enabled: Effect.Effect<string[] | false>
-}
-
-export function make(input: {
-  readonly directory: string
-  readonly worktree: string
-  readonly fs: FSUtil.Interface
-  readonly npm: Npm.Interface
-  readonly processes: AppProcess.Interface
-  readonly experimentalOxfmt?: boolean
-}) {
-  const disabled = false as const
-  const findUp = (target: string) => input.fs.findUp(target, input.directory, input.worktree)
-  const readText = (file: string) => input.fs.readFileString(file).pipe(Effect.orElseSucceed(() => ""))
-  const commandOutput = (command: string[]) =>
-    input.processes
-      .run(
-        ChildProcess.make(command[0], command.slice(1), {
-          cwd: input.directory,
-          extendEnv: true,
-          stdin: "ignore",
-        }),
-      )
-      .pipe(Effect.option)
-
-  const gofmt: Info = {
-    name: "gofmt",
-    extensions: [".go"],
-    enabled: Effect.sync(() => {
-      const match = which("gofmt")
-      return match ? [match, "-w", "$FILE"] : disabled
-    }),
-  }
-
-  const mix: Info = {
-    name: "mix",
-    extensions: [".ex", ".exs", ".eex", ".heex", ".leex", ".neex", ".sface"],
-    enabled: Effect.sync(() => {
-      const match = which("mix")
-      return match ? [match, "format", "$FILE"] : disabled
-    }),
-  }
-
-  const prettier: Info = {
-    name: "prettier",
-    environment: { BUN_BE_BUN: "1" },
-    extensions: [
-      ".js",
-      ".jsx",
-      ".mjs",
-      ".cjs",
-      ".ts",
-      ".tsx",
-      ".mts",
-      ".cts",
-      ".html",
-      ".htm",
-      ".css",
-      ".scss",
-      ".sass",
-      ".less",
-      ".vue",
-      ".svelte",
-      ".json",
-      ".jsonc",
-      ".yaml",
-      ".yml",
-      ".toml",
-      ".xml",
-      ".md",
-      ".mdx",
-      ".graphql",
-      ".gql",
-    ],
-    enabled: Effect.gen(function* () {
-      for (const file of yield* findUp("package.json")) {
-        if (!hasDependency(yield* input.fs.readJson(file), "prettier")) continue
-        const bin = yield* input.npm.which("prettier")
-        if (bin) return [bin, "--write", "$FILE"]
-      }
-      return disabled
-    }).pipe(Effect.orElseSucceed(() => disabled)),
-  }
-
-  const oxfmt: Info = {
-    name: "oxfmt",
-    environment: { BUN_BE_BUN: "1" },
-    extensions: [".js", ".jsx", ".mjs", ".cjs", ".ts", ".tsx", ".mts", ".cts"],
-    enabled: Effect.gen(function* () {
-      for (const file of yield* findUp("package.json")) {
-        if (!hasDependency(yield* input.fs.readJson(file), "oxfmt")) continue
-        const bin = yield* input.npm.which("oxfmt")
-        if (bin) return [bin, "$FILE"]
-      }
-      return disabled
-    }).pipe(Effect.orElseSucceed(() => disabled)),
-  }
-
-  const biome: Info = {
-    name: "biome",
-    environment: { BUN_BE_BUN: "1" },
-    extensions: [
-      ".js",
-      ".jsx",
-      ".mjs",
-      ".cjs",
-      ".ts",
-      ".tsx",
-      ".mts",
-      ".cts",
-      ".html",
-      ".htm",
-      ".css",
-      ".scss",
-      ".sass",
-      ".less",
-      ".vue",
-      ".svelte",
-      ".json",
-      ".jsonc",
-      ".yaml",
-      ".yml",
-      ".toml",
-      ".xml",
-      ".md",
-      ".mdx",
-      ".graphql",
-      ".gql",
-    ],
-    enabled: Effect.gen(function* () {
-      const found = yield* Effect.forEach(["biome.json", "biome.jsonc"], findUp, { concurrency: "unbounded" })
-      if (!found.some((items) => items.length > 0)) return disabled
-      const bin = yield* input.npm.which("@biomejs/biome")
-      return bin ? [bin, "format", "--write", "$FILE"] : disabled
-    }).pipe(Effect.orElseSucceed(() => disabled)),
-  }
-
-  const zig: Info = {
-    name: "zig",
-    extensions: [".zig", ".zon"],
-    enabled: Effect.sync(() => {
-      const match = which("zig")
-      return match ? [match, "fmt", "$FILE"] : disabled
-    }),
-  }
-
-  const clang: Info = {
-    name: "clang-format",
-    extensions: [".c", ".cc", ".cpp", ".cxx", ".c++", ".h", ".hh", ".hpp", ".hxx", ".h++", ".ino", ".C", ".H"],
-    enabled: Effect.gen(function* () {
-      if (!(yield* findUp(".clang-format")).length) return disabled
-      const match = which("clang-format")
-      return match ? [match, "-i", "$FILE"] : disabled
-    }).pipe(Effect.orElseSucceed(() => disabled)),
-  }
-
-  const ktlint: Info = {
-    name: "ktlint",
-    extensions: [".kt", ".kts"],
-    enabled: Effect.sync(() => {
-      const match = which("ktlint")
-      return match ? [match, "-F", "$FILE"] : disabled
-    }),
-  }
-
-  const ruff: Info = {
-    name: "ruff",
-    extensions: [".py", ".pyi"],
-    enabled: Effect.gen(function* () {
-      if (!which("ruff")) return disabled
-      for (const config of ["pyproject.toml", "ruff.toml", ".ruff.toml"]) {
-        const found = yield* findUp(config)
-        if (!found.length) continue
-        if (config !== "pyproject.toml" || (yield* readText(found[0])).includes("[tool.ruff]")) {
-          return ["ruff", "format", "$FILE"]
-        }
-      }
-      for (const dependency of ["requirements.txt", "pyproject.toml", "Pipfile"]) {
-        const found = yield* findUp(dependency)
-        if (found.length && (yield* readText(found[0])).includes("ruff")) return ["ruff", "format", "$FILE"]
-      }
-      return disabled
-    }).pipe(Effect.orElseSucceed(() => disabled)),
-  }
-
-  const air: Info = {
-    name: "air",
-    extensions: [".R"],
-    enabled: Effect.gen(function* () {
-      const bin = which("air")
-      if (!bin) return disabled
-      const output = yield* commandOutput([bin, "--help"])
-      if (output._tag === "None" || output.value.exitCode !== 0) return disabled
-      const first = output.value.stdout.toString("utf8").split("\n")[0]
-      return first.includes("R language") && first.includes("formatter") ? [bin, "format", "$FILE"] : disabled
-    }),
-  }
-
-  const uv: Info = {
-    name: "uv",
-    extensions: [".py", ".pyi"],
-    enabled: Effect.gen(function* () {
-      const bin = which("uv")
-      if (!bin) return disabled
-      const output = yield* commandOutput([bin, "format", "--help"])
-      return output._tag === "Some" && output.value.exitCode === 0
-        ? [bin, "format", "--", "$FILE"]
-        : disabled
-    }),
-  }
-
-  const rubocop = executable("rubocop", [".rb", ".rake", ".gemspec", ".ru"], ["--autocorrect", "$FILE"])
-  const standardrb = executable("standardrb", [".rb", ".rake", ".gemspec", ".ru"], ["--fix", "$FILE"])
-  const htmlbeautifier = executable("htmlbeautifier", [".erb", ".html.erb"], ["$FILE"])
-  const dart = executable("dart", [".dart"], ["format", "$FILE"])
-
-  const ocamlformat: Info = {
-    name: "ocamlformat",
-    extensions: [".ml", ".mli"],
-    enabled: Effect.gen(function* () {
-      if (!(yield* findUp(".ocamlformat")).length) return disabled
-      const match = which("ocamlformat")
-      return match ? [match, "-i", "$FILE"] : disabled
-    }).pipe(Effect.orElseSucceed(() => disabled)),
-  }
-
-  const terraform = executable("terraform", [".tf", ".tfvars"], ["fmt", "$FILE"])
-  const latexindent = executable("latexindent", [".tex"], ["-w", "-s", "$FILE"])
-  const gleam = executable("gleam", [".gleam"], ["format", "$FILE"])
-  const shfmt = executable("shfmt", [".sh", ".bash"], ["-w", "$FILE"])
-  const nixfmt = executable("nixfmt", [".nix"], ["$FILE"])
-  const rustfmt = executable("rustfmt", [".rs"], ["$FILE"])
-
-  const pint: Info = {
-    name: "pint",
-    extensions: [".php"],
-    enabled: Effect.gen(function* () {
-      for (const file of yield* findUp("composer.json")) {
-        const json = yield* input.fs.readJson(file)
-        if (hasRecordKey(json, "require", "laravel/pint") || hasRecordKey(json, "require-dev", "laravel/pint")) {
-          return ["./vendor/bin/pint", "$FILE"]
-        }
-      }
-      return disabled
-    }).pipe(Effect.orElseSucceed(() => disabled)),
-  }
-
-  const ormolu = executable("ormolu", [".hs"], ["-i", "$FILE"])
-  const cljfmt = executable("cljfmt", [".clj", ".cljs", ".cljc", ".edn"], ["fix", "--quiet", "$FILE"])
-  const dfmt = executable("dfmt", [".d"], ["-i", "$FILE"])
-
-  return [
-    gofmt,
-    mix,
-    oxfmt,
-    prettier,
-    biome,
-    zig,
-    clang,
-    ktlint,
-    ruff,
-    air,
-    uv,
-    rubocop,
-    standardrb,
-    htmlbeautifier,
-    dart,
-    ocamlformat,
-    terraform,
-    latexindent,
-    gleam,
-    shfmt,
-    nixfmt,
-    rustfmt,
-    pint,
-    ormolu,
-    cljfmt,
-    dfmt,
-  ] satisfies Info[]
-}
-
-function executable(name: string, extensions: readonly string[], args: string[]): Info {
-  return {
-    name,
-    extensions,
-    enabled: Effect.sync(() => {
-      const match = which(name)
-      return match ? [match, ...args] : false
-    }),
-  }
-}
-
-function hasDependency(input: unknown, dependency: string) {
-  return hasRecordKey(input, "dependencies", dependency) || hasRecordKey(input, "devDependencies", dependency)
-}
-
-function hasRecordKey(input: unknown, field: string, key: string) {
-  if (!isRecord(input)) return false
-  return isRecord(input[field]) && key in input[field]
-}
-
-function isRecord(input: unknown): input is Record<string, unknown> {
-  return Boolean(input && typeof input === "object" && !Array.isArray(input))
-}

packages/core/src/location-services.ts

@@ -8,7 +8,6 @@ import { LayerNode } from "@opencode-ai/util/effect/layer-node"
 import { Node } from "@opencode-ai/util/effect/app-node"
 import { Bus } from "./bus"
 import { FileMutation } from "./file-mutation"
-import { Formatter } from "./formatter"
 import { FileSystem } from "./filesystem"
 import { FileSystemSearch } from "./filesystem/search"
 import { Generate } from "./generate"
@@ -74,7 +73,6 @@ const locationServiceNodes = [
   InstructionDiscovery.node,
   LocationMutation.node,
   FileMutation.node,
-  Formatter.node,
   MCP.node,
   Permission.node,
   Tool.node,

packages/core/src/plugin/hooks.ts

@@ -2,7 +2,6 @@ export * as PluginHooks from "./hooks"
 
 import type { AISDKHooks } from "@opencode-ai/plugin/effect/aisdk"
 import type { SessionHooks } from "@opencode-ai/plugin/effect/session"
-import type { ShellHooks } from "@opencode-ai/plugin/effect/shell"
 import type { ToolHooks } from "@opencode-ai/plugin/effect/tool"
 import { Context, Effect, Layer, Scope } from "effect"
 import { makeLocationNode } from "@opencode-ai/util/effect/app-node"
@@ -11,7 +10,6 @@ import { State } from "../state"
 export interface Domains {
   readonly aisdk: AISDKHooks
   readonly session: SessionHooks
-  readonly shell: ShellHooks
   readonly tool: ToolHooks
 }
 

packages/core/src/plugin/host.ts

@@ -296,9 +296,6 @@ export const make = Effect.fn("PluginHost.make")(function* (plugin: import("../p
           })
         }),
     },
-    shell: {
-      hook: (name, callback) => hooks.register("shell", name, callback),
-    },
     tool: {
       transform: (callback) =>
         tools

packages/core/src/plugin/internal.ts

@@ -16,7 +16,6 @@ import { ConfigSkillPlugin } from "../config/plugin/skill"
 import { ConfigWebSearchPlugin } from "../config/plugin/websearch"
 import { Bus } from "../bus"
 import { FileMutation } from "../file-mutation"
-import { Formatter } from "../formatter"
 import { Form } from "../form"
 import { FileSystem } from "../filesystem"
 import { FSUtil } from "@opencode-ai/util/fs-util"
@@ -69,7 +68,6 @@ const services = Effect.fn("PluginInternal.services")(function* () {
   const config = yield* Config.Service
   const bus = yield* Bus.Service
   const mutation = yield* FileMutation.Service
-  const formatter = yield* Formatter.Service
   const filesystem = yield* FileSystem.Service
   const fs = yield* FSUtil.Service
   const global = yield* Global.Service
@@ -100,7 +98,6 @@ const services = Effect.fn("PluginInternal.services")(function* () {
     Context.make(Config.Service, config),
     Context.make(Bus.Service, bus),
     Context.make(FileMutation.Service, mutation),
-    Context.make(Formatter.Service, formatter),
     Context.make(FileSystem.Service, filesystem),
     Context.make(FSUtil.Service, fs),
     Context.make(Global.Service, global),

packages/core/src/plugin/promise.ts

@@ -326,10 +326,6 @@ export function fromPromise(plugin: Plugin) {
               ),
             interrupt: (input) => run(host.session.interrupt({ sessionID: Session.ID.make(input.sessionID) })),
           },
-          shell: {
-            hook: (name, callback) =>
-              register(host.shell.hook(name, (event) => Effect.promise(() => Promise.resolve(callback(event))))),
-          },
         }
 
         const cleanup = yield* Effect.promise(() => Promise.resolve(plugin.setup(context2)))