supabase-cli/docs/supabase/login.md

supabase-login

Connect the Supabase CLI to your Supabase account by logging in with your personal access token.

Your access token is stored securely in native credentials storage. If native credentials storage is unavailable, it will be written to a plain text file at ~/.supabase/access-token.

If this behavior is not desired, such as in a CI environment, you may skip login by specifying the SUPABASE_ACCESS_TOKEN environment variable in other commands.

The Supabase CLI uses the stored token to access Management APIs for projects, functions, secrets, etc.