Lua doc & lobby always on / JWT

Is there some documentation somewhere on what can be done in Lua with prosody/jitsi? Especially around Lobby feature.

We are trying to turn on lobby automatically when the moderator joins the room. We have a setup with Lobby / JWT (with moderator attribute and We don’t want the moderator to have to turn on lobby manually.

Also there is also another problem with our current setup

  • Moderator joins / create a room (JWT moderator attribute true)
  • Moderator turns on lobby (wish this was automatic)
  • Non Moderator joins (JWT moderator attribute false) / Moderator accepts him
  • Moderator drops
  • Moderator cannot join anymore (get stuck in the lobby, shouldn’t need to wait for someone to accept him)

Essentially is there a way for Moderators (with JWT attribute) to be automatically accepted without getting stuck in Lobby?



I would start by reviewing the existing plugins. You could write something that hooks to muc-room-pre-create, muc-occupant-joined, or muc-occupant-pre-join, etc.

This topic may also help: How to get auth_token in muc-room-created and muc-room-destroyed events?


Look in the etc/prosody/conf.d/ file for muc_lobby_whitelist. This can be used to bypass the lobby. If you don’t see that in you cfg, add it under lobby_muc

should be easy

--- mod_muc_lobby_rooms.lua.sav	2020-07-23 21:50:37.000000000 +0200
+++ mod_muc_lobby_rooms.lua	2020-08-03 16:38:45.421840379 +0200
@@ -372,6 +372,13 @@
+    host_module:hook('muc-set-affiliation', function(event)
+        if jid_split(event.jid) ~= 'focus' and event.affiliation == 'owner' then
+	    handle_create_lobby(event);
+        end
+    end);
 -- Extract 'room' param from URL when session is created

if you want to add this to standard Jitsi, all there is to add is a parameter. I guess it’s planned already since this routine that is not called anywhere in the source, it’s purpose should be for something like that.

I don’t think there is anything specific about JWT here; it can happens also with internal authentication (and probably with public access setup but I did not try it).
The fact that a moderator having disconnected by mistake after having enabled the lobby can’t enter again because there is no one to approve the join is a misfeature IMO.
Maybe it could be done by saving somewhere (no idea where in fact :-)) the original owner (see above) and testing if it’s the jid currently disconnecting (no idea how :-)) and then just call room:set_members_only(false); - at this point anyone including the original moderator should be able to join.


Thanks for the pointers!
We were able to address both issues with custom Lua plugin (auto-lobby on when moderator joins) and bypass lobby for authenticated moderators so they dont get stuck in limbo.

Sam - Any chance you can share the custom plugins?

@Sam_Lellouche, could you please share your solution for - custom Lua plugin (auto-lobby on when moderator joins) and bypass lobby for authenticated moderators so they dont get stuck in limbo.

Hi, did that feature about lobby now still default or need modify that marked code?
Is there also a possibility to add a default password…?

Another question too, inside your doc you wrote
Token body should look something like this:

  context: {
    user: {
  moderator: true

My example about jwt are:

$payload = array(
    "aud" => "meeting",
    "iss" => "meeting",
    "sub" => "meeting.domain.tld",
    "exp" => time() + (12*60*60),
    "room" => "$ROOM",
    "context" => array(
        "user" => array(
            "name" => "$name",
            "email" => "$email",
            "avatar" => "",
            "affiliation" => "owner",
        "features" => array(
            "recording" => true,
            "livestreaming" => true,
            "screen-sharing" => true,

Should i change it to

$payload = array(
“aud” => “meeting”,
“iss” => “meeting”,
“sub” => “meeting.domain.tld”,
“exp” => time() + (126060),
“room” => “$ROOM”,
“moderator” => true,
“context” => array(
“user” => array(
“name” => “$name”,
“email” => “$email”,
“avatar” => “”,
“affiliation” => “owner”,
“features” => array(
“recording” => true,
“livestreaming” => true,
“screen-sharing” => true,

Or how i should change it?