This is the proposed FEP-61cf: The OpenWebAuth Protocol. OpenWebAuth is the “single sign-on” mechanism used by Hubzilla, (streams) and other related projects. It allows a browser-based user to log in to services across the Fediverse using a single identity. Once logged in, they can be recognised by other OpenWebAuth-compatible services, …
The proposal fails to sufficiently motivate why existing protocols like OpenId Connect can’t be used given that trusting the user’s home instance seems necessary with this protocol too. The name also is confusingly close to WebAuthn.