Google Sign-In succeeds in browser, but Antigravity stays on login page and throws TypeError: Do not know how to serialize a BigInt (v1.20.6, Windows)

Google Antigravity
1

I’m reporting a login issue on Google Antigravity v1.20.6 on Windows.

Environment

  • App version: 1.20.6

  • OS: Windows 10 / Windows 11 build 10.0.26200.8037

  • Architecture: x64

Issue

When I try to sign in with Google, the browser authentication completes successfully, and the browser shows that authentication has succeeded. The custom protocol callback is triggered and Antigravity is launched again, but the desktop client remains stuck on the “Sign into Google” page and does not complete login.

What happens

  1. Open Antigravity and click Sign in with Google

  2. Browser opens Google authentication page

  3. Google authentication succeeds

  4. Browser shows success page

  5. antigravity://... callback is triggered and the app is launched

  6. Antigravity still stays on the login screen instead of signing in

Relevant observations

  • The browser success page indicates authentication completed successfully

  • The custom protocol callback works and launches Antigravity

  • Local auth callback server starts successfully on localhost

  • Login still does not complete in the app UI

[Auth] AntigravityAuthMainService initialized
[Auth] Localhost server listening on port 56780
[Auth] Localhost server stopped
[error] [uncaught exception in main]: TypeError: Do not know how to serialize a BigInt
[error] TypeError: Do not know how to serialize a BigInt
at JSON.stringify ()