Remove spurious event_id from federation APIs, and convert to POST?

[richvdh]

The following federation APIs have roomIds and eventIds in the path which are completely redundant:

• PUT /_matrix/federation/vN/send_join/{roomId}/{eventId}
• PUT /_matrix/federation/vN/invite/{roomId}/{eventId}
• PUT /_matrix/federation/vN/send_leave/{roomId}/{eventId}
• PUT /_matrix/federation/v1/exchange_third_party_invite/{roomId}

The room_id is given in the body, and the event_id is either in the body or calculated from the hash. Deduplication takes place based on that event id, not on the path params.

The implication of all this is that we could remove the roomId and eventId path params, and convert the request to a POST.

One counter-argument is that it would make sharding by room harder if the roomId was omitted. So maybe we should leave that there (but still remove eventId and switch to POST).

While I'm here: why is PUT /_matrix/federation/v1/3pid/onbind a PUT ?

[turt2live]

tbh the solution here depends on which RESTful guidelines you end up reading.

[richvdh]

these go beyond a wart: they are foot-guns because you can end up using the path param in one place and then the body param in another.

[richvdh]

if we keep both sets of params, what is the correct behaviour when there is a mismatch? a 400 error of some kind?