Create the app
1
Pick or create a Google Cloud project
Open console.cloud.google.com and pick a project for your site, or create one from the project picker (New project). From a terminal:
gcloud projects create <PROJECT_ID> --name="<Your site>". No API needs to be turned on for sign-in.2
Branding and audience
Open Google Auth Platform > Branding (
https://console.cloud.google.com/auth/branding?project=<PROJECT_ID>) and click Get started if asked.- App name: your site’s name (visitors see it when they sign in)
- User support email: an address you read
- Audience: External
- Contact information: your email address
3
Create the client
Open Clients > Create client (
https://console.cloud.google.com/auth/clients?project=<PROJECT_ID>).- Application type: Web application
-
Authorized redirect URIs: your project’s sign-in callback, in this exact format:
Your Supabase reference is shown at the top of the project’s Database > Auth panel.
4
Paste it into your project
In your project, open Database > Auth > OAuth, turn on Google, paste the client ID and secret, and click Save. See Set up user authentication for the rest of the sign-in setup.
Troubleshooting
Error 400: redirect_uri_mismatch
Error 400: redirect_uri_mismatch
The client’s redirect URI must match your project’s callback exactly:
https://{your-supabase}.supabase.co/auth/v1/callback, with your own Supabase reference and no trailing slash.Only some people can sign in
Only some people can sign in
The app is still in Testing, where only its test users can sign in. Open Audience and click Publish app.