Rocket.Chat / Matrix federation: connected but messaging only works one way


I have been running a Rocket.Chat server for a while and everything is working as expected. Now I got curious and installed a Matrix Synapse server alongside to try federation. Both servers are running docker using separate docker-compose files (so they are in separate stacks). In the RC container I opened up port 3300 for the bridge to be reachable.

After some fiddling, I got synapse working (federation tester showing a green light). I added the registration.yaml from the RC GUI to the synapse data dir and added it to the homeserver.yaml. Then I restarted both servers.

Typing /federation dm I was able to send a message to the synapse matrix user (who got automatically invited and, as I understand, autojoined).

The problem is: when replies to the message, the reply does not show up in RC.

Server Setup Information

  • Version of Rocket.Chat Server: 5.4.1
  • Operating System: Debian 11.6
  • Deployment Method: docker (compose)
  • Number of Running Instances: 1
  • DB Replicaset Oplog: yes
  • NodeJS Version: 14.19.3
  • MongoDB Version: 5.0.14
  • Proxy: haproxy
  • Firewalls involved: pfsense (but this should be happening behind the firewall)

While I am waiting for someone to come along who knows how this integration works (because I don’t):

Is anybody actually using this integration (in production)?