Login with U documentation

Let anyone sign in on your site with a U.CASH identity. Standard OpenID Connect: point any OIDC library at the discovery URL and you are done.

Reference: Endpoints, scopes, claims, PKCE, errors, rate limits, domain verification.
Quickstarts: Any OIDC library, next-auth, Passport, and a runnable reference RP.
Logout and notifications Payments: end_session, back-channel logout tokens, verification sample.
Button and brand: The Login with U button kit and usage guidelines.

The 60 second version

issuer:                 https://accounts.u.cash
discovery:              https://accounts.u.cash/.well-known/openid-configuration
flow:                   authorization code + PKCE (S256)
scopes:                 openid, email, profile
id_token:               RS256 (JWKS at /.well-known/jwks.json)

Create an app in the developer portal, verify your domain with one DNS TXT record, add your redirect URI, and drop the button on your page.