fix(mcp): log diagnostic instead of swallowing gateway event rejections

cxbAsDev · cxbAsDev · commit 233dfe8f887b · 2026-07-05T19:25:20.000+08:00
diff --git a/src/mcp/channel-bridge.test.ts b/src/mcp/channel-bridge.test.ts
@@ -34,6 +34,10 @@ type BridgeInternals = {
     event: string;
     payload?: Record<string, unknown>;
   }) => Promise<void>;
+  dispatchGatewayEvent: (event: {
+    event: string;
+    payload?: Record<string, unknown>;
+  }) => Promise<void>;
   handleSessionMessageEvent: (payload: {
     sessionKey: string;
     senderIsOwner?: boolean;
@@ -304,6 +308,52 @@ describe("OpenClawChannelBridge — pendingClaudePermissions / pendingApprovals
     }
   });
 
+  test("a rejected gateway event still emits exactly one diagnostic record with verbose off", async () => {
+    const bridge = makeBridge(false);
+    const writes: string[] = [];
+    const writeSpy = vi
+      .spyOn(process.stderr, "write")
+      .mockImplementation((chunk: string | Uint8Array): boolean => {
+        writes.push(String(chunk));
+        return true;
+      });
+    vi.spyOn(bridge, "handleGatewayEvent").mockRejectedValue(new Error("handler boom"));
+    try {
+      await bridge.dispatchGatewayEvent({ event: "exec.approval.requested", payload: {} });
+
+      expect(writes).toHaveLength(1);
+      expect(writes[0]).toBe("openclaw mcp: gateway event exec.approval.requested failed\n");
+      expect(writes[0]).not.toContain("handler boom");
+    } finally {
+      writeSpy.mockRestore();
+      await bridge.close();
+    }
+  });
+
+  test("a rejected gateway event includes error detail with verbose on", async () => {
+    const bridge = makeBridge(true);
+    const writes: string[] = [];
+    const writeSpy = vi
+      .spyOn(process.stderr, "write")
+      .mockImplementation((chunk: string | Uint8Array): boolean => {
+        writes.push(String(chunk));
+        return true;
+      });
+    vi.spyOn(bridge, "handleGatewayEvent").mockRejectedValue(new Error("handler boom"));
+    try {
+      await bridge.dispatchGatewayEvent({ event: "exec.approval.requested", payload: {} });
+
+      expect(writes).toHaveLength(2);
+      expect(writes[0]).toBe("openclaw mcp: gateway event exec.approval.requested failed\n");
+      expect(writes[1]).toBe(
+        "openclaw mcp: gateway event exec.approval.requested error: Error: handler boom\n",
+      );
+    } finally {
+      writeSpy.mockRestore();
+      await bridge.close();
+    }
+  });
+
   test("sweeper interval is not started before any pending entry is added", async () => {
     const bridge = makeBridge();
     try {
diff --git a/src/mcp/channel-bridge.ts b/src/mcp/channel-bridge.ts
@@ -148,7 +148,7 @@ export class OpenClawChannelBridge {
       scopes: [READ_SCOPE, WRITE_SCOPE, APPROVALS_SCOPE],
       requestTimeoutMs: 180_000,
       onEvent: (event) => {
-        void this.handleGatewayEvent(event).catch(() => {});
+        void this.dispatchGatewayEvent(event);
       },
       onHelloOk: () => {
         this.retryingInitialConnect = false;
@@ -521,6 +521,21 @@ export class OpenClawChannelBridge {
     }
   }
 
+  private async dispatchGatewayEvent(event: EventFrame): Promise<void> {
+    try {
+      await this.handleGatewayEvent(event);
+    } catch (error) {
+      // Always surface a single low-noise record so swallowed gateway event
+      // failures remain observable; the spammy error detail stays behind --verbose.
+      process.stderr.write(`openclaw mcp: gateway event ${event.event} failed\n`);
+      if (this.verbose) {
+        process.stderr.write(
+          `openclaw mcp: gateway event ${event.event} error: ${String(error)}\n`,
+        );
+      }
+    }
+  }
+
   private async handleGatewayEvent(event: EventFrame): Promise<void> {
     switch (event.event) {
       case "session.message":
