fix(opencode): use ACP-reported reasoning effort options (#853)

* fix(opencode): use ACP-reported reasoning effort options

Expose thought_level options from OpenCode ACP to the web UI via RPC/API
instead of hardcoded presets, and validate effort values before setConfigOption.

Fixes #852

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(opencode): sync hub effort after coerced setConfigOption

When resolveThoughtLevelEffort falls back to a different supported value,
roll back session state after a successful ACP update so keepalive and the
web UI do not keep advertising the rejected effort.

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

hub/src/sync/rpcGateway.ts

@@ -13,6 +13,7 @@ import type {
     ListDirectoryResponse,
     OpencodeModelsResponse,
     OpencodeModelSummary,
+    OpencodeReasoningEffortResponse,
     PathExistsResponse,
     SlashCommandsResponse,
     UploadFileResponse
@@ -37,6 +38,7 @@ export type RpcCursorModel = CursorModelSummary
 export type RpcListCursorModelsResponse = CursorModelsResponse
 export type RpcOpencodeModel = OpencodeModelSummary
 export type RpcListOpencodeModelsResponse = OpencodeModelsResponse
+export type RpcListOpencodeReasoningEffortOptionsResponse = OpencodeReasoningEffortResponse
 
 export class RpcGateway {
     constructor(
@@ -258,6 +260,10 @@ export class RpcGateway {
         return await this.machineRpc(machineId, RPC_METHODS.ListOpencodeModelsForCwd, { cwd }) as RpcListOpencodeModelsResponse
     }
 
+    async listOpencodeReasoningEffortOptionsForSession(sessionId: string): Promise<RpcListOpencodeReasoningEffortOptionsResponse> {
+        return await this.sessionRpc(sessionId, RPC_METHODS.ListOpencodeReasoningEffortOptions, {}) as RpcListOpencodeReasoningEffortOptionsResponse
+    }
+
     private async sessionRpc(
         sessionId: string,
         method: string,

hub/src/sync/syncEngine.ts

@@ -29,6 +29,7 @@ import {
     type RpcListCodexModelsResponse,
     type RpcListCursorModelsResponse,
     type RpcListOpencodeModelsResponse,
+    type RpcListOpencodeReasoningEffortOptionsResponse,
     type RpcCursorModel,
     type RpcOpencodeModel,
     type RpcPathExistsResponse,
@@ -49,6 +50,7 @@ export type {
     RpcListCodexModelsResponse,
     RpcListCursorModelsResponse,
     RpcListOpencodeModelsResponse,
+    RpcListOpencodeReasoningEffortOptionsResponse,
     RpcCursorModel,
     RpcOpencodeModel,
     RpcPathExistsResponse,
@@ -1088,4 +1090,8 @@ export class SyncEngine {
     async listOpencodeModelsForCwd(machineId: string, cwd: string): Promise<RpcListOpencodeModelsResponse> {
         return await this.rpcGateway.listOpencodeModelsForCwd(machineId, cwd)
     }
+
+    async listOpencodeReasoningEffortOptionsForSession(sessionId: string): Promise<RpcListOpencodeReasoningEffortOptionsResponse> {
+        return await this.rpcGateway.listOpencodeReasoningEffortOptionsForSession(sessionId)
+    }
 }

hub/src/web/routes/sessions.test.ts

@@ -80,6 +80,14 @@ function createApp(session: Session, opts?: {
         ],
         currentModelId: 'ollama/exaone:4.5-33b-q8'
     })
+    const listOpencodeReasoningEffortOptionsForSession = async () => ({
+        success: true,
+        options: [
+            { value: 'low', name: 'Low' },
+            { value: 'medium', name: 'Medium' }
+        ],
+        currentValue: 'low'
+    })
     const listCursorModelsForSession = async () => ({
         success: true,
         availableModels: [
@@ -103,6 +111,7 @@ function createApp(session: Session, opts?: {
         listCodexModelsForSession,
         listCursorModelsForSession,
         listOpencodeModelsForSession,
+        listOpencodeReasoningEffortOptionsForSession,
         resumeSession,
         reopenSession,
         getSessionExport: opts?.getSessionExport ?? (() => ({
@@ -543,6 +552,33 @@ describe('sessions routes', () => {
         })
     })
 
+    it('returns OpenCode reasoning effort options for active OpenCode sessions', async () => {
+        const session = createSession({
+            metadata: { path: '/tmp/project', host: 'localhost', flavor: 'opencode' }
+        })
+        const { app } = createApp(session)
+
+        const response = await app.request('/api/sessions/session-1/opencode-reasoning-effort-options')
+
+        expect(response.status).toBe(200)
+        expect(await response.json()).toEqual({
+            success: true,
+            options: [
+                { value: 'low', name: 'Low' },
+                { value: 'medium', name: 'Medium' }
+            ],
+            currentValue: 'low'
+        })
+    })
+
+    it('rejects opencode-reasoning-effort-options for non-OpenCode sessions', async () => {
+        const { app } = createApp(createSession())
+
+        const response = await app.request('/api/sessions/session-1/opencode-reasoning-effort-options')
+
+        expect(response.status).toBe(400)
+    })
+
     it('returns OpenCode models for active OpenCode sessions', async () => {
         const session = createSession({
             metadata: { path: '/tmp/project', host: 'localhost', flavor: 'opencode' }

hub/src/web/routes/sessions.ts

@@ -688,6 +688,36 @@ export function createSessionsRoutes(getSyncEngine: () => SyncEngine | null): Ho
         }
     })
 
+    app.get('/sessions/:id/opencode-reasoning-effort-options', async (c) => {
+        const engine = requireSyncEngine(c, getSyncEngine)
+        if (engine instanceof Response) {
+            return engine
+        }
+
+        const sessionResult = requireSessionFromParam(c, engine, { requireActive: true })
+        if (sessionResult instanceof Response) {
+            return sessionResult
+        }
+
+        const flavor = sessionResult.session.metadata?.flavor ?? 'claude'
+        if (flavor !== 'opencode') {
+            return c.json({
+                success: false,
+                error: 'OpenCode reasoning effort options are only available for OpenCode sessions'
+            }, 400)
+        }
+
+        try {
+            const result = await engine.listOpencodeReasoningEffortOptionsForSession(sessionResult.sessionId)
+            return c.json(result)
+        } catch (error) {
+            return c.json({
+                success: false,
+                error: error instanceof Error ? error.message : 'Failed to list OpenCode reasoning effort options'
+            }, 500)
+        }
+    })
+
     app.get('/sessions/:id/cursor-models', async (c) => {
         const engine = requireSyncEngine(c, getSyncEngine)
         if (engine instanceof Response) {