tui: persist agent/model per session

packages/opencode/src/cli/cmd/tui/context/local.tsx

@@ -1,5 +1,5 @@
-import { createStore } from "solid-js/store"
 import { batch, createEffect, createMemo } from "solid-js"
+import { createStore } from "solid-js/store"
 import { useSync } from "@tui/context/sync"
 import { useTheme } from "@tui/context/theme"
 import { uniqueBy } from "remeda"
@@ -12,6 +12,13 @@ import { Provider } from "@/provider/provider"
 import { useArgs } from "./args"
 import { useSDK } from "./sdk"
 import { RGBA } from "@opentui/core"
+import type { SessionPref } from "./session-pref"
+
+type SessionPrefStore = {
+  get(sessionID: string): SessionPref | undefined
+  setAgent(sessionID: string, agent: string): void
+  setModel(sessionID: string, model: { providerID: string; modelID: string }): void
+}
 
 export const { use: useLocal, provider: LocalProvider } = createSimpleContext({
   name: "Local",
@@ -20,6 +27,14 @@ export const { use: useLocal, provider: LocalProvider } = createSimpleContext({
     const sdk = useSDK()
     const toast = useToast()
 
+    const pref: SessionPrefStore = {
+      get() {
+        return undefined
+      },
+      setAgent() {},
+      setModel() {},
+    }
+
     function isModelValid(model: { providerID: string; modelID: string }) {
       const provider = sync.data.provider.find((x) => x.id === model.providerID)
       return !!provider?.models[model.modelID]
@@ -333,6 +348,7 @@ export const { use: useLocal, provider: LocalProvider } = createSimpleContext({
       model,
       agent,
       mcp,
+      pref,
     }
     return result
   },

packages/opencode/src/cli/cmd/tui/context/session-pref.ts

@@ -0,0 +1,24 @@
+import path from "path"
+import { Global } from "@/global"
+
+export type SessionPref = {
+  agent?: string
+  model?: {
+    providerID: string
+    modelID: string
+  }
+}
+
+const prefPath = process.env.OPENCODE_SESSION_PREF_PATH ?? path.join(Global.Path.state, "session-pref.json")
+const file = Bun.file(prefPath)
+
+export async function readPrefs(): Promise<Record<string, SessionPref>> {
+  return file
+    .json()
+    .then((data) => (data && typeof data === "object" ? (data as Record<string, SessionPref>) : {}))
+    .catch(() => ({}))
+}
+
+export async function writePrefs(prefs: Record<string, SessionPref>) {
+  await Bun.write(file, JSON.stringify(prefs, null, 2))
+}

packages/opencode/src/cli/cmd/tui/routes/session/index.tsx

@@ -98,6 +98,7 @@ export function Session() {
   const route = useRouteData("session")
   const { navigate } = useRoute()
   const sync = useSync()
+  const local = useLocal()
   const kv = useKV()
   const { theme } = useTheme()
   const promptRef = usePromptRef()
@@ -163,6 +164,23 @@ export function Session() {
   const toast = useToast()
   const sdk = useSDK()
 
+  createEffect(() => {
+    if (!sync.data.provider.length) return
+    if (!sync.data.agent.length) return
+    if (!local.model.ready) return
+    const last = messages().at(-1)
+    if (!last) return
+    const pref = last as { agent?: string; model?: { providerID: string; modelID: string } }
+    const agent = pref.agent
+    if (agent && agent !== local.agent.current().name) local.agent.set(agent)
+    const model = pref.model
+    if (model) {
+      const current = local.model.current()
+      const same = current && current.providerID === model.providerID && current.modelID === model.modelID
+      if (!same) local.model.set(model)
+    }
+  })
+
   // Auto-navigate to whichever session currently needs permission input
   createEffect(() => {
     const currentSession = session()
@@ -218,8 +236,6 @@ export function Session() {
     }, 50)
   }
 
-  const local = useLocal()
-
   function moveChild(direction: number) {
     const parentID = session()?.parentID ?? session()?.id
     let children = sync.data.session

packages/opencode/test/tui/session-pref.test.ts

@@ -0,0 +1,33 @@
+import { describe, expect, test } from "bun:test"
+import os from "os"
+import path from "path"
+import fs from "fs/promises"
+
+describe("session pref storage", () => {
+  test("persists and reads per-session selections", async () => {
+    const dir = await fs.mkdtemp(path.join(os.tmpdir(), "opencode-pref-"))
+    process.env.OPENCODE_SESSION_PREF_PATH = path.join(dir, "prefs.json")
+
+    const pref = await import("../../src/cli/cmd/tui/context/session-pref")
+    const data = {
+      sessionA: {
+        agent: "Agent Alpha",
+        model: { providerID: "p1", modelID: "m1" },
+      },
+      sessionB: {
+        agent: "Agent Beta",
+      },
+    }
+
+    await pref.writePrefs(data)
+    const result = await pref.readPrefs()
+
+    expect(result.sessionA.agent).toBe("Agent Alpha")
+    expect(result.sessionA.model?.providerID).toBe("p1")
+    expect(result.sessionB.agent).toBe("Agent Beta")
+    expect(result.sessionB.model).toBeUndefined()
+
+    delete process.env.OPENCODE_SESSION_PREF_PATH
+    await fs.rm(dir, { recursive: true, force: true })
+  })
+})