fix(googlechat): normalize auth transport headers

CHANGELOG.md

@@ -29,6 +29,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Google Chat: normalize custom Google auth transport headers before google-auth/gaxios interceptors run, restoring webhook token verification when certificate retrieval expects Fetch `Headers`. Fixes #76742. Thanks @donbowman.
 - Docs/WhatsApp: merge the duplicate top-level `web` objects in the gateway channel config example so copy-pasted WhatsApp config keeps both `web.whatsapp` and reconnect settings. Fixes #76619. Thanks @WadydX.
 - Plugins/Anthropic: expose Claude thinking profiles from the bundled provider-policy artifact so non-runtime callers keep Opus 4.7 `adaptive`, `xhigh`, and `max` instead of downgrading to `high`. Fixes #76779. Thanks @tomascupr and @iAbhi001.
 - Discord/native commands: skip slash-command registration and cleanup REST calls when `channels.discord.commands.native=false`, letting low-power gateways start without waiting on disabled native-command lifecycle requests. Fixes #76202. Thanks @vincentkoc.

extensions/googlechat/src/google-auth.runtime.test.ts

@@ -8,9 +8,24 @@ const mocks = vi.hoisted(() => ({
     hostnameAllowlist: hosts,
   })),
   fetchWithSsrFGuard: vi.fn(),
-  gaxiosCtor: vi.fn(function MockGaxios(this: { defaults: Record<string, unknown> }, defaults) {
-    this.defaults = defaults as Record<string, unknown>;
-  }),
+  gaxiosCtor: vi.fn(
+    function MockGaxios(
+      this: {
+        defaults: Record<string, unknown>;
+        interceptors: {
+          request: { add: ReturnType<typeof vi.fn> };
+          response: { add: ReturnType<typeof vi.fn> };
+        };
+      },
+      defaults,
+    ) {
+      this.defaults = defaults as Record<string, unknown>;
+      this.interceptors = {
+        request: { add: vi.fn() },
+        response: { add: vi.fn() },
+      };
+    },
+  ),
 }));
 
 vi.mock("openclaw/plugin-sdk/ssrf-runtime", () => ({
@@ -330,6 +345,9 @@ describe("googlechat google auth runtime", () => {
           fetchImplementation: expect.any(Function),
         },
       });
+      expect(transport.interceptors.request.add).toHaveBeenCalledWith({
+        resolved: expect.any(Function),
+      });
       expect("window" in globalThis).toBe(false);
     } finally {
       if (originalWindowDescriptor) {
@@ -338,6 +356,19 @@ describe("googlechat google auth runtime", () => {
     }
   });
 
+  it("normalizes Google auth request headers before upstream interceptors run", async () => {
+    const config = {
+      headers: { "x-test": "1" },
+      url: new URL("https://www.googleapis.com/oauth2/v1/certs"),
+    };
+
+    const normalized = __testing.normalizeGoogleAuthPreparedRequestHeaders(config);
+
+    expect(normalized.headers).toBeInstanceOf(Headers);
+    expect(normalized.headers.has("x-test")).toBe(true);
+    expect(normalized.headers.get("x-test")).toBe("1");
+  });
+
   it("rejects service-account credentials that override Google auth endpoints", async () => {
     await expect(
       resolveValidatedGoogleChatCredentials({

extensions/googlechat/src/google-auth.runtime.ts

@@ -20,6 +20,9 @@ type GoogleAuthRuntime = {
   OAuth2Client: GoogleAuthModule["OAuth2Client"];
 };
 type GoogleAuthTransport = InstanceType<GaxiosModule["Gaxios"]>;
+type GoogleAuthRequestWithUnknownHeaders = RequestInit & {
+  headers?: unknown;
+};
 type GuardedGoogleAuthRequestInit = RequestInit & {
   agent?: unknown;
   cert?: unknown;
@@ -67,6 +70,24 @@ const MAX_GOOGLE_CHAT_SERVICE_ACCOUNT_FILE_BYTES = 64 * 1024;
 let googleAuthRuntimePromise: Promise<GoogleAuthRuntime> | null = null;
 let googleAuthTransportPromise: Promise<GoogleAuthTransport> | null = null;
 
+function normalizeGoogleAuthPreparedRequestHeaders<T extends GoogleAuthRequestWithUnknownHeaders>(
+  config: T,
+): T & { headers: Headers } {
+  if (!(config.headers instanceof Headers)) {
+    config.headers = new Headers(config.headers as HeadersInit | undefined);
+  }
+  return config as T & { headers: Headers };
+}
+
+function installGoogleAuthHeaderCompatibilityInterceptor(
+  transport: GoogleAuthTransport,
+): GoogleAuthTransport {
+  transport.interceptors.request.add({
+    resolved: async (config) => normalizeGoogleAuthPreparedRequestHeaders(config),
+  });
+  return transport;
+}
+
 function asNullableObjectRecord(value: unknown): Record<string, unknown> | null {
   return value !== null && typeof value === "object" ? (value as Record<string, unknown>) : null;
 }
@@ -504,9 +525,11 @@ export async function getGoogleAuthTransport(): Promise<GoogleAuthTransport> {
     googleAuthTransportPromise = (async () => {
       try {
         const { Gaxios } = await loadGoogleAuthRuntime();
-        return new Gaxios({
-          fetchImplementation: createGoogleAuthFetch(),
-        });
+        return installGoogleAuthHeaderCompatibilityInterceptor(
+          new Gaxios({
+            fetchImplementation: createGoogleAuthFetch(),
+          }),
+        );
       } catch (error) {
         googleAuthTransportPromise = null;
         throw error;
@@ -534,6 +557,7 @@ export const __testing = {
     googleAuthRuntimePromise = null;
     googleAuthTransportPromise = null;
   },
+  normalizeGoogleAuthPreparedRequestHeaders,
   resolveGoogleAuthEnvProxyUrl,
   validateGoogleChatServiceAccountCredentials,
 };