diff --git a/.changeset/witty-carpets-wait.md b/.changeset/witty-carpets-wait.md
new file mode 100644
index 00000000000..31de091758d
--- /dev/null
+++ b/.changeset/witty-carpets-wait.md
@@ -0,0 +1,5 @@
+---
+"@clerk/clerk-js": patch
+"@clerk/shared": patch
+---
+WIP ignore
diff --git a/packages/clerk-js/src/ui/components/GoogleOneTap/one-tap-start.tsx b/packages/clerk-js/src/ui/components/GoogleOneTap/one-tap-start.tsx
index ce4f5a97c2b..418bfbd1a88 100644
--- a/packages/clerk-js/src/ui/components/GoogleOneTap/one-tap-start.tsx
+++ b/packages/clerk-js/src/ui/components/GoogleOneTap/one-tap-start.tsx
@@ -66,9 +66,10 @@ function OneTapStartInternal(): JSX.Element | null {
   useEffect(() => {
     if (initializedGoogle && !user?.id && !isPromptedRef.current) {
       initializedGoogle.accounts.id.prompt(notification => {
-        // Close the modal, when the user clicks outside the prompt or cancels
-        if (notification.getMomentType() === 'skipped') {
-          // Unmounts the component will cause the useEffect cleanup function from below to be called
+        // Close Google One Tap when user dismisses or skips the prompt
+        // Using methods compatible with both FedCM and legacy modes
+        // https://developers.google.com/identity/gsi/web/guides/fedcm-migration
+        if (notification.isSkippedMoment?.() || notification.isDismissedMoment?.()) {
           clerk.closeGoogleOneTap();
         }
       });
diff --git a/packages/clerk-js/src/utils/one-tap.ts b/packages/clerk-js/src/utils/one-tap.ts
index 4b56a2b083a..5acedaaaa7b 100644
--- a/packages/clerk-js/src/utils/one-tap.ts
+++ b/packages/clerk-js/src/utils/one-tap.ts
@@ -15,13 +15,38 @@ interface InitializeProps {
   use_fedcm_for_prompt?: boolean;
 }
 
+// PromptMomentNotification methods
+// See: https://developers.google.com/identity/gsi/web/reference/js-reference#PromptMomentNotification
 interface PromptMomentNotification {
-  getMomentType: () => 'display' | 'skipped' | 'dismissed';
+  // Moment type detection
+  getMomentType?: () => 'display' | 'skipped' | 'dismissed';
+
+  // Display moment methods - NOT supported when FedCM is enabled
+  isDisplayMoment?: () => boolean;
+  isDisplayed?: () => boolean;
+  isNotDisplayed?: () => boolean;
+  getNotDisplayedReason?: () =>
+    | 'browser_not_supported'
+    | 'invalid_client'
+    | 'missing_client_id'
+    | 'opt_out_or_no_session'
+    | 'secure_http_required'
+    | 'suppressed_by_user'
+    | 'unregistered_origin'
+    | 'unknown_reason';
+
+  // Skipped moment methods - partially supported in FedCM (no user_cancel reason)
+  isSkippedMoment?: () => boolean;
+  getSkippedReason?: () => 'auto_cancel' | 'user_cancel' | 'tap_outside' | 'issuing_failed';
+
+  // Dismissed moment methods - fully supported in FedCM
+  isDismissedMoment?: () => boolean;
+  getDismissedReason?: () => 'credential_returned' | 'cancel_called' | 'flow_restarted';
 }
 
 interface OneTapMethods {
   initialize: (params: InitializeProps) => void;
-  prompt: (promptListener: (promptMomentNotification: PromptMomentNotification) => void) => void;
+  prompt: (promptListener?: (notification: PromptMomentNotification) => void) => void;
   cancel: () => void;
 }
 
diff --git a/packages/shared/src/types/clerk.ts b/packages/shared/src/types/clerk.ts
index e18204bed10..7bdb9e55a3e 100644
--- a/packages/shared/src/types/clerk.ts
+++ b/packages/shared/src/types/clerk.ts
@@ -1518,10 +1518,21 @@ export type GoogleOneTapProps = GoogleOneTapRedirectUrlProps & {
    */
   itpSupport?: boolean;
   /**
-   * FedCM enables more private sign-in flows without requiring the use of third-party cookies.
-   * The browser controls user settings, displays user prompts, and only contacts an Identity Provider such as Google after explicit user consent is given.
-   * Backwards compatible with browsers that still support third-party cookies.
+   * FedCM enables more private sign-in flows without requiring third-party cookies.
+   * The browser controls user settings, displays user prompts, and only contacts
+   * an Identity Provider such as Google after explicit user consent.
    *
+   * Requirements:
+   * - Chrome 117+ or Edge 117+ (falls back to legacy mode in older browsers)
+   * - HTTPS in production
+   * - Proper Content Security Policy (CSP) configuration
+   *
+   * Troubleshooting:
+   * - If you see "NetworkError: Failed to execute 'get'" or CORS errors, check your CSP headers
+   * - Add `connect-src https://accounts.google.com` to your CSP policy
+   * - Set to `false` to temporarily use legacy mode while debugging
+   *
+   * @see https://developers.google.com/identity/gsi/web/guides/fedcm-migration
    * @default true
    */
   fedCmSupport?: boolean;