# Join room using HTTP call return "ack" only

**URL:** <https://janus.discourse.group/t/join-room-using-http-call-return-ack-only/906>\
**Category:** General\
**Created:** [March 8, 2024, 2:04am UTC](https://janus.discourse.group/t/join-room-using-http-call-return-ack-only/906 "2024-03-08T02:04:55Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![dungdv](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@dungdv](https://janus.discourse.group/u/dungdv)\
**Post date:** [March 8, 2024, 2:04am UTC](https://janus.discourse.group/t/join-room-using-http-call-return-ack-only/906/1 "2024-03-08T02:04:55Z")

</div>

Hi, I have a room like this:

```auto
{
    "janus": "success",
    "session_id": 266646464364358,
    "transaction": "MUcPg6Wu5jhr",
    "sender": 4377145860586972,
    "plugindata": {
        "plugin": "janus.plugin.videoroom",
        "data": {
            "videoroom": "success",
            "list": [
                {
                    "room": 11,
                    "description": "Room 11",
                    "pin_required": false,
                    "is_private": false,
                    "max_publishers": 3,
                    "bitrate": 0,
                    "fir_freq": 0,
                    "require_pvtid": false,
                    "require_e2ee": false,
                    "dummy_publisher": false,
                    "notify_joining": false,
                    "audiocodec": "opus",
                    "videocodec": "vp8",
                    "opus_fec": true,
                    "record": false,
                    "lock_record": false,
                    "num_participants": 0,
                    "audiolevel_ext": true,
                    "audiolevel_event": false,
                    "videoorient_ext": true,
                    "playoutdelay_ext": true,
                    "transport_wide_cc_ext": true
                }
            ]
        }
    }
}

```

Now I want to join this room, I use this params:

```auto
join params {
  janus: 'message',
  plugin: 'janus.plugin.videoroom',
  session_id: 8568607942621781,
  handle_id: 3267543887867048,
  transaction: 'VeENHRbBTHWI',
  body: { request: 'join', room: 11, ptype: 'publisher', display: 'test' }
}

```

But it’s return the ack only:

```auto
{
    "janus": "ack",
    "session_id": 8568607942621781,
    "transaction": "VeENHRbBTHWI"
}

```

I dont know why it not return “joined” event, can you help? I am using https call, not socket

---

<div class="post-metadata">

**Author:** ![dungdv](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@dungdv](https://janus.discourse.group/u/dungdv)\
**Post date:** [March 8, 2024, 2:09am UTC](https://janus.discourse.group/t/join-room-using-http-call-return-ack-only/906/2 "2024-03-08T02:09:10Z")

</div>

> [@dungdv](#):
>
> `266646464364358`

after call “join”, I check the participant inside this room, but it return empty list:

```auto
{
    "janus": "success",
    "session_id": 4397550774641519,
    "transaction": "h8LgvUJxVXGk",
    "sender": 8580331991428173,
    "plugindata": {
        "plugin": "janus.plugin.videoroom",
        "data": {
            "videoroom": "participants",
            "room": 11,
            "participants": []
        }
    }
}

```

---

<div class="post-metadata">

**Author:** ![lorenzo](https://yyz2.discourse-cdn.com/free1/user_avatar/janus.discourse.group/lorenzo/32/425_2.png) [@lorenzo](https://janus.discourse.group/u/lorenzo)\
**Post date:** [March 8, 2024, 8:27am UTC](https://janus.discourse.group/t/join-room-using-http-call-return-ack-only/906/3 "2024-03-08T08:27:21Z")

</div>

> [@dungdv](#):
>
> it return empty list

That’s normal. That list only contains active users, those that published a PeerConnection. You may want to read the [documentation](https://janus.conf.meetecho.com/docs/videoroom) first.

---

<div class="post-metadata">

**Author:** ![dungdv](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@dungdv](https://janus.discourse.group/u/dungdv)\
**Post date:** [March 8, 2024, 8:58am UTC](https://janus.discourse.group/t/join-room-using-http-call-return-ack-only/906/4 "2024-03-08T08:58:21Z")

</div>

> [@lorenzo](#):
>
> That’s normal. That list only contains active users, those that published a PeerConnection. You may want to read the [documentation](https://janus.conf.meetecho.com/docs/videoroom) first.

Hi, I am follow the document, I have the question below:

1. I use htpp cal to join a room , this is the question above that I asked
2. With the `same params`, I use socket to call join room, that return joined event after the ack. Then I got “joined” event after that. Then I check the listParticipants like this:

```auto
{
   "janus": "success",
   "session_id": 4915235918595631,
   "transaction": "of8Ht4ZseGD5",
   "sender": 4680094336352450,
   "plugindata": {
       "plugin": "janus.plugin.videoroom",
       "data": {
           "videoroom": "participants",
           "room": 1,
           "participants": [
               {
                   "id": 2442054571610922,
                   "display": "ios webrtc",
                   "publisher": false
               }
           ]
       }
   }
}

```

So I want to ask, if method 1 and 2 does success joined the room, why I get empty `listParticipants` when using method 1? Thanks