sign_in_provider — Sign-in Provider

Location: payload · Vendor: Firebase

Names the identity provider used for this sign-in (e.g. "password", "google.com", "anonymous"). On a real Firebase ID token this appears nested inside the firebase claim object (firebase.sign_in_provider), not as its own top-level claim — worth knowing when writing a parser.

Defined in Firebase Auth ID token structure.

Decode a JWT and inspect its sign_in_provider claim in the TokenPrism debugger — free, entirely in your browser.