matrix-spec-proposals/proposals/2689-fix-e2ee-for-guests.md

# MSC2689: Allow guests to operate in encrypted rooms

[#751](https://github.com/matrix-org/matrix-doc/pull/751) granted guest users access to several endpoints in order to allow them to use E2EE.
I found that guests are able to join encrypted rooms and read messages from other members. But when the
guest wants to send an event into the room the client receives a "guest access not allowed" error
for the `/rooms/{room_id}/members` endpoint. I assume the client tries to read the list of room members
to prepare the encryption of the event for the present members. Tests with a patched Synapse showed that
allowing guests to use this endpoint results in a normal behaviour and enables guests to communicate in
encrypted rooms.


## Proposal

Allow guests to use the `GET /_matrix/client/r0/rooms/{room_id}/members` endpoint to enable them to
operate properly in encrypted rooms.


## Alternatives

The list of room members could also be read from the sync. However that would not work with Lazy Loading.