[codex] improve Codex plan mode compatibility

cli/src/codex/appServerTypes.ts

@@ -53,7 +53,10 @@ export interface CollaborationModeListItem {
 }
 
 export interface CollaborationModeListResponse {
-    data?: CollaborationModeListItem[];
+    data?: Array<CollaborationModeListItem | string>;
+    modes?: Array<CollaborationModeListItem | string>;
+    collaborationModes?: Array<CollaborationModeListItem | string>;
+    items?: Array<CollaborationModeListItem | string>;
     [key: string]: unknown;
 }
 

cli/src/codex/codexRemoteLauncher.test.ts

@@ -969,6 +969,23 @@ describe('codexRemoteLauncher', () => {
         });
     });
 
+    it('recognizes alternate collaboration mode list envelopes', async () => {
+        harness.collaborationModeResponse = { collaborationModes: [{ id: 'plan' }] };
+        const { session } = createSessionStub(['plan this'], {
+            permissionMode: 'default',
+            collaborationMode: 'plan',
+            model: 'gpt-5.4'
+        });
+
+        const exitReason = await codexRemoteLauncher(session as never);
+
+        expect(exitReason).toBe('exit');
+        expect(harness.startTurnParams).toHaveLength(1);
+        expect(harness.startTurnParams[0]?.collaborationMode).toMatchObject({
+            mode: 'plan'
+        });
+    });
+
     it('retries plan turns without collaborationMode when the runtime rejects the field', async () => {
         harness.startTurnErrors.push(new Error('unknown field collaborationMode'));
         const { session, sessionEvents } = createSessionStub(['plan this'], {
@@ -1036,7 +1053,7 @@ describe('codexRemoteLauncher', () => {
         });
     });
 
-    it('falls back to a normal turn when collaborationMode/list omits plan', async () => {
+    it('still attempts plan mode when collaborationMode/list omits plan', async () => {
         harness.collaborationModeResponse = { data: [{ mode: 'default' }] };
         const { session, sessionEvents } = createSessionStub(['plan this'], {
             permissionMode: 'default',
@@ -1048,9 +1065,10 @@ describe('codexRemoteLauncher', () => {
 
         expect(exitReason).toBe('exit');
         expect(harness.startTurnParams).toHaveLength(1);
-        expect(harness.startTurnParams[0]?.collaborationMode).toBeUndefined();
-        expect(harness.startTurnParams[0]?.model).toBe('gpt-5.4');
-        expect(sessionEvents).toContainEqual({
+        expect(harness.startTurnParams[0]?.collaborationMode).toMatchObject({
+            mode: 'plan'
+        });
+        expect(sessionEvents).not.toContainEqual({
             type: 'message',
             message: 'Plan mode is not supported by this Codex runtime. Sent as a normal turn instead.'
         });

cli/src/codex/codexRemoteLauncher.ts

@@ -266,9 +266,9 @@ class CodexRemoteLauncher extends RemoteLauncherBase {
                 return false;
             }
 
-            return message.includes('requires experimentalapi')
-                || message.includes('unknown field')
+            return message.includes('experimentalapi')
                 || message.includes('unsupported')
+                || message.includes('unknown')
                 || message.includes('unrecognized')
                 || message.includes('unexpected')
                 || message.includes('invalid field');
@@ -278,7 +278,10 @@ class CodexRemoteLauncher extends RemoteLauncherBase {
             const record = asRecord(response);
             const candidates = [
                 Array.isArray(response) ? response : undefined,
-                Array.isArray(record?.data) ? record.data : undefined
+                Array.isArray(record?.data) ? record.data : undefined,
+                Array.isArray(record?.modes) ? record.modes : undefined,
+                Array.isArray(record?.collaborationModes) ? record.collaborationModes : undefined,
+                Array.isArray(record?.items) ? record.items : undefined
             ];
 
             for (const candidate of candidates) {
@@ -288,7 +291,9 @@ class CodexRemoteLauncher extends RemoteLauncherBase {
                         return true;
                     }
                     const entryRecord = asRecord(entry);
-                    const mode = asString(entryRecord?.mode) ?? asString(entryRecord?.name);
+                    const mode = asString(entryRecord?.mode)
+                        ?? asString(entryRecord?.name)
+                        ?? asString(entryRecord?.id);
                     if (mode === 'plan') {
                         return true;
                     }
@@ -2275,7 +2280,6 @@ class CodexRemoteLauncher extends RemoteLauncherBase {
             }
         });
         let supportsTurnCollaborationMode = true;
-        let supportsPlanCollaborationMode = true;
         let supportsGoals = true;
         try {
             await appServerClient.setExperimentalFeatureEnablement({ enablement: { goals: true } });
@@ -2289,7 +2293,7 @@ class CodexRemoteLauncher extends RemoteLauncherBase {
             const hasPlanMode = responseContainsPlanCollaborationMode(response);
             logger.debug(`[Codex] collaborationMode/list plan=${hasPlanMode}`);
             if (!hasPlanMode) {
-                supportsPlanCollaborationMode = false;
+                logger.debug('[Codex] collaborationMode/list did not report plan; will still attempt collaborationMode until rejected');
             }
         } catch (error) {
             logger.debug(`[Codex] collaborationMode/list failed: ${errorMessage(error)}`);
@@ -2735,8 +2739,7 @@ class CodexRemoteLauncher extends RemoteLauncherBase {
                     model: session.getModel() ?? message.mode.model
                 };
                 const shouldSendCollaborationMode = supportsTurnCollaborationMode
-                    && Boolean(mode.collaborationMode)
-                    && (mode.collaborationMode !== 'plan' || supportsPlanCollaborationMode);
+                    && Boolean(mode.collaborationMode);
                 const buildParams = (suppressCollaborationMode: boolean) => buildTurnStartParams({
                     threadId: this.currentThreadId!,
                     message: message.message,
@@ -2749,7 +2752,7 @@ class CodexRemoteLauncher extends RemoteLauncherBase {
                 });
                 if (
                     mode.collaborationMode === 'plan'
-                    && (!supportsTurnCollaborationMode || !supportsPlanCollaborationMode)
+                    && !supportsTurnCollaborationMode
                 ) {
                     session.sendSessionEvent({
                         type: 'message',