You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
79 lines
2.8 KiB
Markdown
79 lines
2.8 KiB
Markdown
# MSC 1794 - Federation v2 Invite API
|
|
|
|
This proposal adds a new `/invite` API to federation that supports different
|
|
room versions.
|
|
|
|
## Motivation
|
|
|
|
It is planned for future room versions to be able to change the format of events
|
|
in various ways. To support this, all servers must know the room version
|
|
whenever they need to parse an event. Currently the `/invite` API does not
|
|
include the room version, so the target server would be unable to parse the event included in the payload.
|
|
|
|
## Proposal
|
|
|
|
Add a new version of the invite API under the prefix `/_matrix/federation/v2`,
|
|
which has a payload of:
|
|
|
|
```
|
|
PUT /_matrix/federation/v2/invite/<room_id>/<event_id>
|
|
|
|
{
|
|
"room_version": <room_version>,
|
|
"event": { ... },
|
|
"invite_room_state": [ ... ]
|
|
}
|
|
```
|
|
|
|
The differences between this and `v1` are:
|
|
|
|
1. The payload in `v1` is the event, while in `v2` the event is instead placed
|
|
under an `"event"` key. This is for consistency with other APIs, and to allow
|
|
extra data to be added to the request payload separately from the event.
|
|
2. A required field called `"room_version"` is added that specifies the room
|
|
version.
|
|
3. The `"invite_room_state"` is moved from the `unsigned` section of the event
|
|
to a top level key. The key `invite_room_state` being in the `event.unsigned`
|
|
was a hack due to point 1. above.
|
|
|
|
|
|
The response is identical to `v1`, except that:
|
|
|
|
1. If the receiving server does not support the given room version the
|
|
appropriate incompatible-room-version error is returned, in the same way
|
|
as e.g. for `/make_join` APIs.
|
|
2. The response payload is no longer in the format of `[200, { ... }]`, and is
|
|
instead simply the `{ ... }` portion. This fixes a historical accident to
|
|
bring the invite API into line with the rest of the federation API.
|
|
|
|
|
|
If a call to `v2` `/invite` results in an unrecognised request exception **AND**
|
|
the room version is `1` or `2` then the sending server should retry the request
|
|
with the `v1` API.
|
|
|
|
|
|
## Alternatives
|
|
|
|
|
|
### Reusing V1 API
|
|
|
|
One alternative is to add a `room_version` query string parameter to the `v1`
|
|
`/invite` API in a similar way as for the `/make_join` APIs. However, older
|
|
servers would ignore the query string parameter while processing an incoming
|
|
`/invite` request, resulting in the server attempting to parse the event in the
|
|
old `v1` format. This would likely result in either a `400` or `500` response,
|
|
which the sending server could interpret as the receiving server not supporting
|
|
the room version.
|
|
|
|
This method, however, is fragile and could easily mask legitimate `400` and
|
|
`500` errors that are not due to not supporting the room version.
|
|
|
|
|
|
### Using V1 API for V1 room versions
|
|
|
|
Instead of all servers attempting to use the new API and falling back if the API
|
|
is not found, servers could instead always use the current API for V1 and V2
|
|
rooms.
|
|
|
|
However, this would not allow us to deprecate the `v1` API.
|