At first, we tried to make our implementation OIDC compatible. As such "openid", "profile" scopes, id tokens and "/userinfo" were all supported. Then we realized that there is a fundamental incompatibility between OpenID and our user identifiers. So we dropped most of the OIDC code.

We could borrow some OIDC stuff, such as the "/userinfo" endpoint. We didn't because we already have atproto endpoint to achieve this, and because we want to keep the requirements needed to implement a PDS as light as possibe.

Might the emerging GNAP standard be more compatible with atproto identifiers? www.rfc-editor.org/rfc/rfc9635 > This protocol solves many of the same use cases as OAuth 2.0 OpenID Connect. > GNAP seeks to provide functionality and solve use cases that OAuth 2.0 cannot easily or cleanly address.