Some responses formats in the federation API specifications use the form [200, res] in which res is the JSON object containing the actual response for the
affected endpoints. This was due to a mishap while building synapse's federation
features, and has been left as is because fixing it would induce backward
incompatibility.
This proposal proposes a backward compatible alternative
Add a new version of the following endpoints under the prefix
/_matrix/federation/v2:
PUT /_matrix/federation/v2/send_join/{roomId}/{eventId}PUT /_matrix/federation/v2/send_leave/{roomId}/{eventId}
Which are the exact same endpoints as their equivalents under the v1 prefix,
except for the response format, which changes from:
[
200,
res
]
To:
res
Where res is the JSON object containing the response to a request directed at
one of the affected endpoints.
This proposal doesn't address the PUT /_matrix/federation/v1/invite/{roomId}/{eventId} endpoint since
MSC1794 already takes care
of it.
If a call to any of the v2 endpoints described in this proposal results in an
unrecognised request exception (i.e. in a response with a 400 or a 404 status
code), then the sending server should retry the request with the v1 API.
An alternative solution would be to make the change in the v1 federation API,
but would break backward compatibility, thus would be harder to manage.