sdk: fail fast spawn requests on spawn manager errors

Author: willwashburn

packages/sdk/src/client.test.ts

@@ -188,6 +188,39 @@ describe('RelayClient', () => {
       // Should not throw
       expect(() => (client as any).processFrame(errorEnvelope)).not.toThrow();
     });
+
+    it('rejects pending spawn when SpawnManager is disabled', async () => {
+      const client = new RelayClient({ reconnect: false, quiet: true });
+      (client as any)._state = 'READY';
+      const sendMock = vi.fn().mockReturnValue(true);
+      (client as any).send = sendMock;
+
+      const spawnPromise = client.spawn(
+        {
+          name: 'Worker',
+          cli: 'codex',
+          task: 'Do work',
+        },
+        10000
+      );
+
+      const errorEnvelope: Envelope<ErrorPayload> = {
+        v: 1,
+        type: 'ERROR',
+        id: 'err-spawn-disabled',
+        ts: Date.now(),
+        payload: {
+          code: 'INTERNAL' as any,
+          message: 'SpawnManager not enabled. Configure spawnManager: true in daemon config.',
+          fatal: false,
+        },
+      };
+
+      (client as any).processFrame(errorEnvelope);
+
+      await expect(spawnPromise).rejects.toThrow('SpawnManager not enabled');
+      expect((client as any).pendingSpawns.size).toBe(0);
+    });
   });
 
   describe('sendMessage', () => {

packages/sdk/src/client.ts

@@ -1849,6 +1849,21 @@ export class RelayClient {
       console.error('[sdk] Server error:', envelope.payload);
     }
 
+    const errorMessage = envelope.payload.message || 'Server error';
+    const isSpawnManagerDisabled =
+      envelope.payload.code === 'INTERNAL' &&
+      /spawnmanager not enabled/i.test(errorMessage);
+
+    // Fail fast for spawn-related operations when daemon cannot service them.
+    // Without this, spawn/release/input/list-workers calls sit until timeout.
+    if (isSpawnManagerDisabled) {
+      const err = new Error(errorMessage);
+      this.rejectPendingSpawns(err);
+      this.rejectPendingReleases(err);
+      this.rejectPendingSendInputs(err);
+      this.rejectPendingListWorkers(err);
+    }
+
     if (envelope.payload.code === 'RESUME_TOO_OLD') {
       this.resumeToken = undefined;
       this.sessionId = undefined;
@@ -1861,6 +1876,11 @@ export class RelayClient {
       }
       this._destroyed = true;
     }
+
+    // Surface server-side ERROR frames to SDK consumers.
+    if (this.onError) {
+      this.onError(new Error(errorMessage));
+    }
   }
 
   private handleDisconnect(): void {