Mastodon API /api/v1/accounts/identity_proofs
Whether or not we want to use this in PleromaFE, we should probably implement the API for compatibility anyway. This doesn't mean we explicitly support Keybase; that's just the only consumer of this API.
Undocumented, so I opened an issue in the upstream docs repo: https://source.joinmastodon.org/mastodon/docs/issues/16
Mastodon PR: https://github.com/tootsuite/mastodon/pull/10297
Discussion/criticism/controversy welcome in the comments