fix(session): use session selection for commands

packages/app/src/components/prompt-input/submit.ts

@@ -76,6 +76,27 @@ export async function sendFollowupDraft(input: FollowupSendInput) {
     return true
   }
 
+  const select = async () => {
+    const session = input.session()
+    if (session?.agent !== input.draft.agent) {
+      await input.api.switchAgent({ sessionID: input.draft.sessionID, agent: input.draft.agent })
+    }
+    if (
+      session?.model?.providerID === input.draft.model.providerID &&
+      session.model.id === input.draft.model.modelID &&
+      (session.model.variant ?? "default") === (input.draft.variant ?? "default")
+    )
+      return
+    await input.api.switchModel({
+      sessionID: input.draft.sessionID,
+      model: {
+        id: input.draft.model.modelID,
+        providerID: input.draft.model.providerID,
+        variant: input.draft.variant,
+      },
+    })
+  }
+
   const [head, ...tail] = text.split(" ")
   const cmd = head?.startsWith("/") ? head.slice(1) : undefined
   if (cmd && input.sync.data.command.find((item) => item.name === cmd)) {
@@ -86,18 +107,13 @@ export async function sendFollowupDraft(input: FollowupSendInput) {
         return false
       }
 
+      await select()
       const messageID = Identifier.ascending("message")
       await input.api.command({
         sessionID: input.draft.sessionID,
         id: messageID,
         command: cmd,
         arguments: tail.join(" "),
-        agent: input.draft.agent,
-        model: {
-          id: input.draft.model.modelID,
-          providerID: input.draft.model.providerID,
-          variant: input.draft.variant,
-        },
         files: await Promise.all(
           images.map(async (attachment) => ({
             uri: await blobDataUrl(attachment.blob, attachment.mime),
@@ -167,24 +183,7 @@ export async function sendFollowupDraft(input: FollowupSendInput) {
       return false
     }
 
-    const session = input.session()
-    if (session?.agent !== input.draft.agent) {
-      await input.api.switchAgent({ sessionID: input.draft.sessionID, agent: input.draft.agent })
-    }
-    if (
-      session?.model?.providerID !== input.draft.model.providerID ||
-      session.model.id !== input.draft.model.modelID ||
-      (session.model.variant ?? "default") !== (input.draft.variant ?? "default")
-    ) {
-      await input.api.switchModel({
-        sessionID: input.draft.sessionID,
-        model: {
-          id: input.draft.model.modelID,
-          providerID: input.draft.model.providerID,
-          variant: input.draft.variant,
-        },
-      })
-    }
+    await select()
 
     await input.api.prompt({
       sessionID: input.draft.sessionID,
@@ -524,14 +523,22 @@ export function createPromptSubmit(input: PromptSubmitInput) {
         clearInput()
         const messageID = Identifier.ascending("message")
         serverSync().session.set("session_status", session.id, { type: "busy" })
-        sdk()
-          .api.session.command({
+        void (async () => {
+          if (session.agent !== agent) await sdk().api.session.switchAgent({ sessionID: session.id, agent })
+          if (
+            session.model?.providerID !== model.providerID ||
+            session.model.id !== model.modelID ||
+            (session.model.variant ?? "default") !== (variant ?? "default")
+          )
+            await sdk().api.session.switchModel({
+              sessionID: session.id,
+              model: { id: model.modelID, providerID: model.providerID, variant },
+            })
+          await sdk().api.session.command({
             sessionID: session.id,
             id: messageID,
             command: commandName,
             arguments: args.join(" "),
-            agent,
-            model: { id: model.modelID, providerID: model.providerID, variant },
             files: await Promise.all(
               images.map(async (attachment) => ({
                 uri: await blobDataUrl(attachment.blob, attachment.mime),
@@ -539,14 +546,14 @@ export function createPromptSubmit(input: PromptSubmitInput) {
               })),
             ),
           })
-          .catch((err) => {
-            serverSync().session.set("session_status", session.id, { type: "idle" })
-            showToast({
-              title: language.t("prompt.toast.commandSendFailed.title"),
-              description: formatServerError(err, language.t, language.t("common.requestFailed")),
-            })
-            restoreInput()
+        })().catch((err) => {
+          serverSync().session.set("session_status", session.id, { type: "idle" })
+          showToast({
+            title: language.t("prompt.toast.commandSendFailed.title"),
+            description: formatServerError(err, language.t, language.t("common.requestFailed")),
           })
+          restoreInput()
+        })
         return
       }
     }

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

@@ -193,8 +193,6 @@ export type Endpoint5_13Input = {
   readonly id?: SessionMessage.ID | undefined
   readonly command: string
   readonly arguments?: string | undefined
-  readonly agent?: Agent.ID | undefined
-  readonly model?: Model.Ref | undefined
   readonly files?: ReadonlyArray<PromptInput.FileAttachment> | undefined
   readonly agents?: ReadonlyArray<AgentAttachment> | undefined
   readonly skills?: ReadonlyArray<PromptInput.SkillAttachment> | undefined

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

@@ -431,8 +431,6 @@ const Endpoint5_13 = (raw: RawClient["server.session"]) => (input: Endpoint5_13I
         id: input["id"],
         command: input["command"],
         arguments: input["arguments"],
-        agent: input["agent"],
-        model: input["model"],
         files: input["files"],
         agents: input["agents"],
         skills: input["skills"],

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

@@ -635,8 +635,6 @@ export function make(options: ClientOptions) {
               id: input["id"],
               command: input["command"],
               arguments: input["arguments"],
-              agent: input["agent"],
-              model: input["model"],
               files: input["files"],
               agents: input["agents"],
               skills: input["skills"],

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

@@ -3485,8 +3485,6 @@ export type SessionCommandInput = {
     readonly id?: string | null
     readonly command: string
     readonly arguments?: string | null
-    readonly agent?: string | null
-    readonly model?: { readonly id: string; readonly providerID: string; readonly variant?: string } | null
     readonly files?: ReadonlyArray<{
       readonly uri: string
       readonly name?: string
@@ -3508,8 +3506,6 @@ export type SessionCommandInput = {
     readonly id?: string | null
     readonly command: string
     readonly arguments?: string | null
-    readonly agent?: string | null
-    readonly model?: { readonly id: string; readonly providerID: string; readonly variant?: string } | null
     readonly files?: ReadonlyArray<{
       readonly uri: string
       readonly name?: string
@@ -3531,8 +3527,6 @@ export type SessionCommandInput = {
     readonly id?: string | null
     readonly command: string
     readonly arguments?: string | null
-    readonly agent?: string | null
-    readonly model?: { readonly id: string; readonly providerID: string; readonly variant?: string } | null
     readonly files?: ReadonlyArray<{
       readonly uri: string
       readonly name?: string
@@ -3550,58 +3544,10 @@ export type SessionCommandInput = {
     readonly delivery?: "steer" | "queue" | null
     readonly resume?: boolean | null
   }["arguments"]
-  readonly agent?: {
-    readonly id?: string | null
-    readonly command: string
-    readonly arguments?: string | null
-    readonly agent?: string | null
-    readonly model?: { readonly id: string; readonly providerID: string; readonly variant?: string } | null
-    readonly files?: ReadonlyArray<{
-      readonly uri: string
-      readonly name?: string
-      readonly description?: string
-      readonly mention?: { readonly start: number; readonly end: number; readonly text: string }
-    }>
-    readonly agents?: ReadonlyArray<{
-      readonly name: string
-      readonly mention?: { readonly start: number; readonly end: number; readonly text: string }
-    }>
-    readonly skills?: ReadonlyArray<{
-      readonly id: string
-      readonly mention?: { readonly start: number; readonly end: number; readonly text: string }
-    }>
-    readonly delivery?: "steer" | "queue" | null
-    readonly resume?: boolean | null
-  }["agent"]
-  readonly model?: {
-    readonly id?: string | null
-    readonly command: string
-    readonly arguments?: string | null
-    readonly agent?: string | null
-    readonly model?: { readonly id: string; readonly providerID: string; readonly variant?: string } | null
-    readonly files?: ReadonlyArray<{
-      readonly uri: string
-      readonly name?: string
-      readonly description?: string
-      readonly mention?: { readonly start: number; readonly end: number; readonly text: string }
-    }>
-    readonly agents?: ReadonlyArray<{
-      readonly name: string
-      readonly mention?: { readonly start: number; readonly end: number; readonly text: string }
-    }>
-    readonly skills?: ReadonlyArray<{
-      readonly id: string
-      readonly mention?: { readonly start: number; readonly end: number; readonly text: string }
-    }>
-    readonly delivery?: "steer" | "queue" | null
-    readonly resume?: boolean | null
-  }["model"]
   readonly files?: {
     readonly id?: string | null
     readonly command: string
     readonly arguments?: string | null
-    readonly agent?: string | null
-    readonly model?: { readonly id: string; readonly providerID: string; readonly variant?: string } | null
     readonly files?: ReadonlyArray<{
       readonly uri: string
       readonly name?: string
@@ -3623,8 +3569,6 @@ export type SessionCommandInput = {
     readonly id?: string | null
     readonly command: string
     readonly arguments?: string | null
-    readonly agent?: string | null
-    readonly model?: { readonly id: string; readonly providerID: string; readonly variant?: string } | null
     readonly files?: ReadonlyArray<{
       readonly uri: string
       readonly name?: string
@@ -3646,8 +3590,6 @@ export type SessionCommandInput = {
     readonly id?: string | null
     readonly command: string
     readonly arguments?: string | null
-    readonly agent?: string | null
-    readonly model?: { readonly id: string; readonly providerID: string; readonly variant?: string } | null
     readonly files?: ReadonlyArray<{
       readonly uri: string
       readonly name?: string
@@ -3669,8 +3611,6 @@ export type SessionCommandInput = {
     readonly id?: string | null
     readonly command: string
     readonly arguments?: string | null
-    readonly agent?: string | null
-    readonly model?: { readonly id: string; readonly providerID: string; readonly variant?: string } | null
     readonly files?: ReadonlyArray<{
       readonly uri: string
       readonly name?: string
@@ -3692,8 +3632,6 @@ export type SessionCommandInput = {
     readonly id?: string | null
     readonly command: string
     readonly arguments?: string | null
-    readonly agent?: string | null
-    readonly model?: { readonly id: string; readonly providerID: string; readonly variant?: string } | null
     readonly files?: ReadonlyArray<{
       readonly uri: string
       readonly name?: string

packages/core/src/models-dev.ts

@@ -1,11 +1,8 @@
-import path from "path"
-import { Context, Duration, Effect, Layer, Option, Schedule, Schema } from "effect"
+import { Context, Duration, Effect, Layer, Option, Schedule, Schema, Semaphore } from "effect"
 import { HttpClient, HttpClientRequest } from "effect/unstable/http"
 import { ModelsDev } from "@opencode-ai/schema/models-dev"
 import { Money } from "@opencode-ai/schema/money"
 import { App } from "./app"
-import { Global } from "@opencode-ai/util/global"
-import { Flock } from "@opencode-ai/util/flock"
 import { Hash } from "@opencode-ai/util/hash"
 import { FSUtil } from "@opencode-ai/util/fs-util"
 import { Bus } from "./bus"
@@ -13,6 +10,7 @@ import { makeGlobalNode } from "@opencode-ai/util/effect/app-node"
 import { httpClient } from "@opencode-ai/util/effect/app-node-platform"
 import { Model } from "./model"
 import { Provider } from "./provider"
+import { KV } from "./kv"
 
 export const CatalogModelStatus = Schema.Literals(["alpha", "beta", "deprecated"])
 export type CatalogModelStatus = typeof CatalogModelStatus.Type
@@ -537,6 +535,18 @@ export type Options = typeof Options.Type
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/ModelsDev") {}
 
+const CatalogJson = Schema.fromJsonString(Schema.Record(Schema.String, Schema.Unknown))
+const Cache = Schema.Struct({
+  updatedAt: Schema.Number,
+  body: CatalogJson,
+})
+const defaultSource = "https://models.opencode.ai"
+
+function cacheKey(source: string) {
+  if (source === defaultSource) return "models-dev:catalog"
+  return `models-dev:catalog:${Hash.fast(source)}`
+}
+
 export const layer = (options?: Options) =>
   Layer.effect(
     Service,
@@ -544,7 +554,7 @@ export const layer = (options?: Options) =>
       const fs = yield* FSUtil.Service
       const bus = yield* Bus.Service
       const app = yield* App.Metadata
-      const global = yield* Global.Service
+      const kv = yield* KV.Service
       const http = HttpClient.filterStatusOk(
         (yield* HttpClient.HttpClient).pipe(
           HttpClient.retryTransient({
@@ -555,21 +565,28 @@ export const layer = (options?: Options) =>
         ),
       )
 
-      const source = options?.url || "https://models.opencode.ai"
+      const source = options?.url || defaultSource
       const fetch = options?.fetch ?? true
       const userAgent = App.useragent(app)
-      const filepath = path.join(
-        global.cache,
-        source === "https://models.opencode.ai" ? "models.json" : `models-${Hash.fast(source)}.json`,
-      )
+      const key = cacheKey(source)
       const ttl = Duration.minutes(5)
-      const lockKey = `models-dev:${filepath}`
+      const lock = Semaphore.makeUnsafe(1)
+
+      const loadFromCache = Effect.fnUntraced(function* () {
+        const value = yield* kv.get(key)
+        const cached = Schema.decodeUnknownOption(Cache)(value)
+        if (Option.isSome(cached))
+          return {
+            catalog: cached.value.body as Record<string, SourceProvider>,
+            updatedAt: cached.value.updatedAt,
+          }
+        if (value !== undefined) yield* kv.remove(key)
+      })
 
       const fresh = Effect.fnUntraced(function* () {
-        const stat = yield* fs.stat(filepath).pipe(Effect.catch(() => Effect.succeed(undefined)))
-        if (!stat) return false
-        const mtime = Option.getOrElse(stat.mtime, () => new Date(0)).getTime()
-        return Date.now() - mtime < Duration.toMillis(ttl)
+        const cached = yield* loadFromCache()
+        if (!cached) return false
+        return Date.now() - cached.updatedAt < Duration.toMillis(ttl)
       })
 
       const fetchApi = Effect.fn("ModelsDev.fetchApi")(function* () {
@@ -581,15 +598,12 @@ export const layer = (options?: Options) =>
         )
       })
 
-      const loadFromDisk = fs.readJson(options?.file ?? filepath).pipe(
-        Effect.map((input) => input as Record<string, SourceProvider>),
-        Effect.catch((error) => {
-          if (options?.file === undefined && error._tag === "FileSystemError" && error.method === "readJson") {
-            return fs.remove(filepath, { force: true }).pipe(Effect.ignore, Effect.as(undefined))
-          }
-          return Effect.succeed(undefined)
-        }),
-      )
+      const loadFromFile = options?.file
+        ? fs.readJson(options.file).pipe(
+            Effect.map((input) => input as Record<string, SourceProvider>),
+            Effect.catch(() => Effect.succeed(undefined)),
+          )
+        : Effect.succeed(undefined)
 
       const loadSnapshot = Effect.sync(() =>
         typeof OPENCODE_MODELS_DEV === "undefined" ? undefined : OPENCODE_MODELS_DEV,
@@ -597,33 +611,27 @@ export const layer = (options?: Options) =>
 
       const fetchAndWrite = Effect.fn("ModelsDev.fetchAndWrite")(function* () {
         const text = yield* fetchApi()
-        const tempfile = `${filepath}.${process.pid}.${Date.now()}.tmp`
-        yield* fs.writeWithDirs(tempfile, text).pipe(
-          Effect.andThen(fs.rename(tempfile, filepath)),
-          Effect.catch((error) =>
-            Effect.gen(function* () {
-              yield* fs.remove(tempfile, { force: true }).pipe(Effect.ignore)
-              return yield* Effect.fail(error)
-            }),
-          ),
-        )
-        return text
+        const catalog = (yield* Schema.decodeUnknownEffect(CatalogJson)(text)) as Record<string, SourceProvider>
+        yield* kv.set(key, { updatedAt: Date.now(), body: text })
+        return catalog
       })
 
       const populate = Effect.gen(function* () {
-        const fromDisk = yield* loadFromDisk
-        if (fromDisk) return normalize(fromDisk)
+        const fromFile = yield* loadFromFile
+        if (fromFile) return normalize(fromFile)
+        const cached = options?.file ? undefined : yield* loadFromCache()
+        if (cached) return normalize(cached.catalog)
         const bundled = yield* loadSnapshot
         if (bundled) return normalize(bundled)
         if (!fetch) return []
-        // Flock is cross-process: concurrent opencode CLIs can race on this cache file.
-        const text = yield* Effect.scoped(
+        const catalog = yield* lock.withPermit(
           Effect.gen(function* () {
-            yield* Flock.effect(lockKey)
+            const stored = options?.file ? undefined : yield* loadFromCache()
+            if (stored) return stored.catalog
             return yield* fetchAndWrite()
           }),
         )
-        return normalize(JSON.parse(text) as Record<string, SourceProvider>)
+        return normalize(catalog)
       }).pipe(Effect.withSpan("ModelsDev.populate"), Effect.orDie)
 
       const [cachedGet, invalidate] = yield* Effect.cachedInvalidateWithTTL(populate, Duration.infinity)
@@ -631,21 +639,19 @@ export const layer = (options?: Options) =>
       const get = (): Effect.Effect<readonly Snapshot[]> => cachedGet
 
       const refresh = Effect.fn("ModelsDev.refresh")(function* (force = false) {
-        if (!force && (yield* fresh())) return
-        yield* Effect.scoped(
-          Effect.gen(function* () {
-            yield* Flock.effect(lockKey)
-            // Re-check under the lock: another process may have refreshed between
-            // our outer check and lock acquisition.
-            if (!force && (yield* fresh())) return
-            yield* fetchAndWrite()
-            yield* invalidate
-            yield* bus.publish(ModelsDev.Event.Refreshed, {})
-          }),
-        ).pipe(
-          Effect.tapCause((cause) => Effect.logError("Failed to fetch models.dev", { cause: cause })),
-          Effect.ignore,
-        )
+        yield* lock
+          .withPermit(
+            Effect.gen(function* () {
+              if (!force && (yield* fresh())) return
+              yield* fetchAndWrite()
+              yield* invalidate
+              yield* bus.publish(ModelsDev.Event.Refreshed, {})
+            }),
+          )
+          .pipe(
+            Effect.tapCause((cause) => Effect.logError("Failed to fetch models.dev", { cause: cause })),
+            Effect.ignore,
+          )
       })
 
       if (fetch && !process.argv.includes("--get-yargs-completions")) {
@@ -661,7 +667,7 @@ export function configured(options?: Options) {
   return makeGlobalNode({
     service: Service,
     layer: layer(options),
-    deps: [FSUtil.node, Bus.node, App.node, Global.node, httpClient],
+    deps: [FSUtil.node, Bus.node, App.node, KV.node, httpClient],
   })
 }
 

packages/core/src/plugin/promise.ts

@@ -310,8 +310,6 @@ export function fromPromise(plugin: Plugin) {
                   ...input,
                   sessionID: Session.ID.make(input.sessionID),
                   id: input.id == null ? undefined : SessionMessage.ID.make(input.id),
-                  agent: input.agent == null ? undefined : Agent.ID.make(input.agent),
-                  model: input.model == null ? undefined : model(input.model),
                   skills: input.skills?.map((skill) => ({ ...skill, id: Skill.ID.make(skill.id) })),
                   arguments: input.arguments ?? undefined,
                   delivery: input.delivery ?? undefined,

packages/core/src/session.ts

@@ -233,8 +233,6 @@ export interface Interface {
     sessionID: SessionSchema.ID
     command: string
     arguments?: string
-    agent?: Agent.ID
-    model?: Model.Ref
     files?: PromptInput.Prompt["files"]
     agents?: PromptInput.Prompt["agents"]
     skills?: PromptInput.Prompt["skills"]
@@ -625,13 +623,13 @@ const layer = Layer.effect(
         const evaluated = yield* commands.evaluate({ name: input.command, arguments: input.arguments })
 
         // TODO(v2 commands): decide whether command-level subtask/background execution belongs in v2 commands.
-        const agent = command.agent ?? input.agent
+        const agent = command.agent
         const commandAgent = yield* Effect.gen(function* () {
           if (!command.agent) return undefined
           const agents = yield* Agent.Service.pipe(Effect.provide(locations.get(session.location)))
           return yield* agents.get(Agent.ID.make(command.agent))
         })
-        const model = command.model ?? commandAgent?.model ?? input.model
+        const model = command.model ?? commandAgent?.model
         if (agent !== undefined && session.agent !== Agent.ID.make(agent))
           yield* result.switchAgent({ sessionID: input.sessionID, agent: Agent.ID.make(agent) })
         if (model !== undefined) yield* result.switchModel({ sessionID: input.sessionID, model })

packages/core/test/models.test.ts

@@ -1,19 +1,17 @@
-import { describe, expect, beforeEach, afterAll, test } from "bun:test"
+import { describe, expect, test } from "bun:test"
 import { Money } from "@opencode-ai/schema/money"
 import { Effect, Layer, Ref } from "effect"
 import { HttpClient, HttpClientResponse } from "effect/unstable/http"
 import { AppNodeBuilder } from "@opencode-ai/core/effect/app-node-builder"
 import { LayerNodePlatform } from "@opencode-ai/util/effect/app-node-platform"
 import { LayerNode } from "@opencode-ai/util/effect/layer-node"
-import { Global } from "@opencode-ai/util/global"
+import { KV } from "@opencode-ai/core/kv"
 import { Model } from "@opencode-ai/core/model"
 import { ModelsDev } from "@opencode-ai/core/models-dev"
 import { Provider } from "@opencode-ai/core/provider"
 import { it } from "./lib/effect"
-import { readFile, rm, writeFile, utimes, mkdir } from "fs/promises"
-import path from "path"
 
-const cacheFile = path.join(Global.Path.cache, "models.json")
+const cacheKey = "models-dev:catalog"
 
 test("normalizes permissive interleaved values to compatibility", () => {
   expect(Model.compatibility("reasoning_text")).toEqual({ reasoningField: "reasoning_text" })
@@ -164,7 +162,18 @@ const makeMockClient = (state: Ref.Ref<MockState>) =>
     }),
   )
 
-const buildLayer = (state: Ref.Ref<MockState>, options: ModelsDev.Options = { fetch: false }) =>
+interface MockCache {
+  readonly values: Map<string, KV.Value>
+}
+
+const makeMockKV = (cache: MockCache) =>
+  Layer.mock(KV.Service, {
+    get: (key) => Effect.sync(() => cache.values.get(key)),
+    set: (key, value) => Effect.sync(() => cache.values.set(key, value)).pipe(Effect.asVoid),
+    remove: (key) => Effect.sync(() => cache.values.delete(key)).pipe(Effect.asVoid),
+  })
+
+const buildLayer = (state: Ref.Ref<MockState>, cache: MockCache, options: ModelsDev.Options = { fetch: false }) =>
   // Layer.fresh is required because the ModelsDev implementation is a module-level Layer constant,
   // and Effect.provide uses a process-global MemoMap by default — without fresh,
   // every test would reuse the cachedInvalidateWithTTL state from the first run.
@@ -172,31 +181,20 @@ const buildLayer = (state: Ref.Ref<MockState>, options: ModelsDev.Options = { fe
     AppNodeBuilder.build(ModelsDev.node, [
       [ModelsDev.node, ModelsDev.configured(options)],
       [LayerNodePlatform.httpClient, Layer.succeed(HttpClient.HttpClient, makeMockClient(state))],
+      [KV.node, makeMockKV(cache)],
     ]),
   )
 
-const writeCacheText = (text: string, mtimeMs?: number) =>
-  Effect.promise(async () => {
-    await mkdir(Global.Path.cache, { recursive: true })
-    await writeFile(cacheFile, text)
-    if (mtimeMs !== undefined) {
-      const t = mtimeMs / 1000
-      await utimes(cacheFile, t, t)
-    }
-  })
+const makeCache = (): MockCache => ({ values: new Map() })
 
-const writeCache = (data: object, mtimeMs?: number) => writeCacheText(JSON.stringify(data), mtimeMs)
+const writeCacheText = (cache: MockCache, text: string, updatedAt = Date.now()) =>
+  cache.values.set(cacheKey, { updatedAt, body: text })
 
-const provided = <A, E>(state: Ref.Ref<MockState>, eff: Effect.Effect<A, E, ModelsDev.Service>) =>
-  eff.pipe(Effect.provide(buildLayer(state)))
+const writeCache = (cache: MockCache, data: object, updatedAt?: number) =>
+  writeCacheText(cache, JSON.stringify(data), updatedAt)
 
-beforeEach(async () => {
-  await rm(cacheFile, { force: true })
-})
-
-afterAll(async () => {
-  await rm(cacheFile, { force: true })
-})
+const provided = <A, E>(state: Ref.Ref<MockState>, cache: MockCache, eff: Effect.Effect<A, E, ModelsDev.Service>) =>
+  eff.pipe(Effect.provide(buildLayer(state, cache)))
 
 const initialState: MockState = {
   body: JSON.stringify(fixture),
@@ -205,12 +203,14 @@ const initialState: MockState = {
 }
 
 describe("ModelsDev Service", () => {
-  it.live("get() returns normalized snapshots from disk when cache file exists", () =>
+  it.live("get() returns normalized snapshots from KV when a cache entry exists", () =>
     Effect.gen(function* () {
-      yield* writeCache(fixture)
+      const cache = makeCache()
+      writeCache(cache, fixture)
       const state = yield* Ref.make(initialState)
       const result = yield* provided(
         state,
+        cache,
         ModelsDev.Service.use((s) => s.get()),
       )
       expect(result).toEqual(fixtureSnapshot)
@@ -219,11 +219,13 @@ describe("ModelsDev Service", () => {
     }),
   )
 
-  it.live("get() returns empty catalog when disk empty, fetch disabled, and no bundled snapshot is injected", () =>
+  it.live("get() returns empty catalog when KV is empty, fetch disabled, and no bundled snapshot is injected", () =>
     Effect.gen(function* () {
+      const cache = makeCache()
       const state = yield* Ref.make(initialState)
       const result = yield* provided(
         state,
+        cache,
         ModelsDev.Service.use((s) => s.get()),
       )
       expect(result).toEqual([])
@@ -232,14 +234,15 @@ describe("ModelsDev Service", () => {
     }),
   )
 
-  it.live("get() recovers from a corrupted cache file by fetching a fresh catalog", () =>
+  it.live("get() recovers from a corrupted KV entry by fetching a fresh catalog", () =>
     Effect.gen(function* () {
-      yield* writeCacheText("{")
+      const cache = makeCache()
+      writeCacheText(cache, "{")
       const state = yield* Ref.make({ ...initialState, body: JSON.stringify(fixture2) })
-      const context = yield* Layer.build(buildLayer(state, { fetch: true }))
+      const context = yield* Layer.build(buildLayer(state, cache, { fetch: true }))
       const result = yield* ModelsDev.Service.use((s) => s.get()).pipe(Effect.provide(context))
       expect(result).toEqual(fixture2Snapshot)
-      expect(yield* Effect.promise(() => readFile(cacheFile, "utf8"))).toBe(JSON.stringify(fixture2))
+      expect(cache.values.get(cacheKey)).toMatchObject({ body: JSON.stringify(fixture2) })
       const final = yield* Ref.get(state)
       expect(final.calls.length).toBe(1)
     }),
@@ -247,9 +250,10 @@ describe("ModelsDev Service", () => {
 
   it.live("uses the default models URL when the configured URL is empty", () =>
     Effect.gen(function* () {
+      const cache = makeCache()
       const state = yield* Ref.make(initialState)
       yield* ModelsDev.Service.use((service) => service.get()).pipe(
-        Effect.provide(buildLayer(state, { url: "", fetch: true })),
+        Effect.provide(buildLayer(state, cache, { url: "", fetch: true })),
       )
       expect((yield* Ref.get(state)).calls[0]?.url).toBe("https://models.opencode.ai/api.json")
     }),
@@ -257,32 +261,31 @@ describe("ModelsDev Service", () => {
 
   it.live("get() is single-flight under concurrent calls", () =>
     Effect.gen(function* () {
-      yield* writeCache(fixture)
+      const cache = makeCache()
       const state = yield* Ref.make(initialState)
-      const results = yield* provided(
-        state,
-        Effect.gen(function* () {
-          const svc = yield* ModelsDev.Service
-          return yield* Effect.all([svc.get(), svc.get(), svc.get(), svc.get(), svc.get()], {
-            concurrency: "unbounded",
-          })
-        }),
-      )
+      const results = yield* Effect.gen(function* () {
+        const svc = yield* ModelsDev.Service
+        return yield* Effect.all([svc.get(), svc.get(), svc.get(), svc.get(), svc.get()], {
+          concurrency: "unbounded",
+        })
+      }).pipe(Effect.provide(buildLayer(state, cache, { fetch: true })))
       for (const result of results) expect(result).toEqual(fixtureSnapshot)
+      expect((yield* Ref.get(state)).calls.length).toBe(1)
     }),
   )
 
-  it.live("get() caches across calls (later disk writes are ignored until invalidate)", () =>
+  it.live("get() caches across calls (later KV writes are ignored until invalidate)", () =>
     Effect.gen(function* () {
-      yield* writeCache(fixture)
+      const cache = makeCache()
+      writeCache(cache, fixture)
       const state = yield* Ref.make(initialState)
       const first = yield* provided(
         state,
+        cache,
         Effect.gen(function* () {
           const svc = yield* ModelsDev.Service
           const a = yield* svc.get()
-          // mutate disk between calls — cache should mask the change
-          yield* writeCache(fixture2)
+          writeCache(cache, fixture2)
           const b = yield* svc.get()
           return { a, b }
         }),
@@ -294,10 +297,12 @@ describe("ModelsDev Service", () => {
 
   it.live("refresh(true) fetches via HttpClient and updates the cache", () =>
     Effect.gen(function* () {
-      yield* writeCache(fixture)
+      const cache = makeCache()
+      writeCache(cache, fixture)
       const state = yield* Ref.make({ ...initialState, body: JSON.stringify(fixture2) })
       const result = yield* provided(
         state,
+        cache,
         Effect.gen(function* () {
           const svc = yield* ModelsDev.Service
           const before = yield* svc.get()
@@ -308,6 +313,7 @@ describe("ModelsDev Service", () => {
       )
       expect(result.before).toEqual(fixtureSnapshot)
       expect(result.after).toEqual(fixture2Snapshot)
+      expect(cache.values.get(cacheKey)).toMatchObject({ body: JSON.stringify(fixture2) })
       const final = yield* Ref.get(state)
       expect(final.calls.length).toBe(1)
       expect(final.calls[0].url).toContain("/api.json")
@@ -315,13 +321,14 @@ describe("ModelsDev Service", () => {
     }),
   )
 
-  it.live("refresh(false) skips fetch when on-disk file is fresh", () =>
+  it.live("refresh(false) skips fetch when the KV entry is fresh", () =>
     Effect.gen(function* () {
-      // Fresh: mtime within the 5-minute TTL.
-      yield* writeCache(fixture, Date.now() - 1000)
+      const cache = makeCache()
+      writeCache(cache, fixture, Date.now() - 1000)
       const state = yield* Ref.make({ ...initialState, body: JSON.stringify(fixture2) })
       yield* provided(
         state,
+        cache,
         ModelsDev.Service.use((s) => s.refresh(false)),
       )
       const final = yield* Ref.get(state)
@@ -329,13 +336,14 @@ describe("ModelsDev Service", () => {
     }),
   )
 
-  it.live("refresh(false) fetches when on-disk file is stale", () =>
+  it.live("refresh(false) fetches when the KV entry is stale", () =>
     Effect.gen(function* () {
-      // Stale: mtime 10 minutes ago, beyond the 5-minute TTL.
-      yield* writeCache(fixture, Date.now() - 10 * 60 * 1000)
+      const cache = makeCache()
+      writeCache(cache, fixture, Date.now() - 10 * 60 * 1000)
       const state = yield* Ref.make({ ...initialState, body: JSON.stringify(fixture2) })
       const after = yield* provided(
         state,
+        cache,
         Effect.gen(function* () {
           const svc = yield* ModelsDev.Service
           yield* svc.refresh(false)
@@ -350,10 +358,12 @@ describe("ModelsDev Service", () => {
 
   it.live("refresh swallows HTTP errors and leaves cache intact", () =>
     Effect.gen(function* () {
-      yield* writeCache(fixture)
+      const cache = makeCache()
+      writeCache(cache, fixture)
       const state = yield* Ref.make({ ...initialState, status: 500, body: "boom" })
       const result = yield* provided(
         state,
+        cache,
         Effect.gen(function* () {
           const svc = yield* ModelsDev.Service
           yield* svc.refresh(true)

packages/protocol/src/groups/session.ts

@@ -341,8 +341,6 @@ export const makeSessionGroup = <I extends HttpApiMiddleware.AnyId, S>(sessionLo
           id: SessionMessage.ID.pipe(Schema.optional),
           command: Schema.String,
           arguments: Schema.String.pipe(Schema.optional),
-          agent: Agent.ID.pipe(Schema.optional),
-          model: Model.Ref.pipe(Schema.optional),
           files: PromptInput.Prompt.fields.files,
           agents: PromptInput.Prompt.fields.agents,
           skills: PromptInput.Prompt.fields.skills,

packages/server/src/handlers/session.ts

@@ -355,8 +355,6 @@ export const SessionHandler = HttpApiBuilder.group(Api, "server.session", (handl
                 id: ctx.payload.id,
                 command: ctx.payload.command,
                 arguments: ctx.payload.arguments,
-                agent: ctx.payload.agent,
-                model: ctx.payload.model,
                 files: ctx.payload.files,
                 agents: ctx.payload.agents,
                 skills: ctx.payload.skills,

packages/tui/src/component/prompt/index.tsx

@@ -1149,15 +1149,23 @@ export function Prompt(props: PromptProps) {
     } else if (slashHead && isCommand) {
       move.startSubmit()
       const model = { providerID: selection.providerID, id: selection.modelID, variant }
+      if (session?.agent !== agent.id) await client.api.session.switchAgent({ sessionID, agent: agent.id })
       const cancelCommit = local.model.trackSessionCommit(sessionID, model)
+      if (
+        session?.model?.providerID !== model.providerID ||
+        session.model.id !== model.id ||
+        (session.model.variant ?? "default") !== (model.variant ?? "default")
+      )
+        await client.api.session.switchModel({ sessionID, model }).catch((error) => {
+          cancelCommit()
+          throw error
+        })
 
       void client.api.session
         .command({
           sessionID,
           command: slashHead.name,
           arguments: slashHead.arguments,
-          agent: agent.id,
-          model,
           files: store.prompt.files,
           agents: store.prompt.agents,
           skills: store.prompt.skills?.length ? store.prompt.skills : undefined,

packages/tui/src/mini/stream-v2.transport.ts

@@ -1653,8 +1653,6 @@ export async function createSessionTransport(input: StreamInput): Promise<Sessio
       )
     }
 
-    const selected = await resolveSelectedModel(input, client, next)
-    if (next.variant && !selected) throw new Error("Cannot select a variant before selecting a model")
     input.trace?.write("send.command", { sessionID: input.sessionID, messageID, command: command.name, delivery })
     return client.session.command(
       {
@@ -1662,8 +1660,6 @@ export async function createSessionTransport(input: StreamInput): Promise<Sessio
         id: messageID,
         command: command.name,
         arguments: command.arguments,
-        agent: next.agent,
-        model: selected,
         files: attachments.files.length ? attachments.files : undefined,
         agents: agents.length ? agents : undefined,
         skills: skills.length ? skills : undefined,
@@ -1706,12 +1702,10 @@ export async function createSessionTransport(input: StreamInput): Promise<Sessio
       const client = sdk
       if (next.agent)
         await client.session.switchAgent({ sessionID: input.sessionID, agent: next.agent }, { signal: next.signal })
-      if (!next.prompt.command) {
-        const selected = await resolveSelectedModel(input, client, next)
-        if (next.variant && !selected) throw new Error("Cannot select a variant before selecting a model")
-        if (selected)
-          await client.session.switchModel({ sessionID: input.sessionID, model: selected }, { signal: next.signal })
-      }
+      const selected = await resolveSelectedModel(input, client, next)
+      if (next.variant && !selected) throw new Error("Cannot select a variant before selecting a model")
+      if (selected)
+        await client.session.switchModel({ sessionID: input.sessionID, model: selected }, { signal: next.signal })
       mergePending(await admitPrompt(next, client, delivery))
       settlementClient = client
     },
@@ -1750,6 +1744,12 @@ export async function createSessionTransport(input: StreamInput): Promise<Sessio
         return
       }
       if (command) {
+        if (next.agent)
+          await client.session.switchAgent({ sessionID: input.sessionID, agent: next.agent }, { signal: next.signal })
+        const selected = await resolveSelectedModel(input, client, next)
+        if (next.variant && !selected) throw new Error("Cannot select a variant before selecting a model")
+        if (selected)
+          await client.session.switchModel({ sessionID: input.sessionID, model: selected }, { signal: next.signal })
         await runTurnWait(
           next,
           messageID,

packages/tui/test/mini/stream-v2.transport.test.ts

@@ -2855,8 +2855,6 @@ describe("V2 mini transport", () => {
       id: "msg_cmd",
       command: "deploy",
       arguments: "prod",
-      agent: "build",
-      model: { providerID: "test", id: "model" },
       files: [
         { uri: "file:///tmp/context.txt", name: "context.txt" },
         {
@@ -2868,9 +2866,11 @@ describe("V2 mini transport", () => {
       skills: [{ id: "api-design", mention: { start: 13, end: 24, text: "/api-design" } }],
       delivery: "steer",
     })
-    // Selection rides the command payload; no separate client-side switch.
-    expect(client.session.switchAgent).not.toHaveBeenCalled()
-    expect(client.session.switchModel).not.toHaveBeenCalled()
+    expect(client.session.switchAgent).toHaveBeenCalledWith({ sessionID: "ses_1", agent: "build" }, expect.anything())
+    expect(client.session.switchModel).toHaveBeenCalledWith(
+      { sessionID: "ses_1", model: { providerID: "test", id: "model" } },
+      expect.anything(),
+    )
     await transport.close()
   })