The refactored LiveKit session dropped track.attach() for remote audio, so no <audio> element was created and remote participants were silent. Also refactors noise suppression to use LiveKit TrackProcessor API, adds input volume gain node bypass at 100%, and exposes __lkDebug() on window for DevTools diagnostics.
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WebSocket Protocol Spec
All client-server communication (except file uploads and
admin panel) happens over a single WebSocket connection.
Messages are JSON with a type and payload.
Message Format
{
"type": "message_type",
"id": "unique-request-id",
"payload": { }
}
type— string, required. Determines how payload is interpreted.id— string, optional. Client-generated UUID for request/response correlation.payload— object, required. Contents vary by type.seq— uint64, server→client broadcast messages only. Monotonically increasing sequence number. Direct responses to a specific client (e.g.error,chat_send_ok,auth_ok) do NOT includeseq.
Server responses to client requests include the same id for correlation.
Authentication
Client → Server
{ "type": "auth", "payload": { "token": "session-token-here", "last_seq": 0 } }
token(string, required) — session token from login.last_seq(uint64, optional) — lastseqreceived by the client. If present and > 0, the server replays missed broadcast events from a 1000-event ring buffer. If the requested seq is too old (no longer in the buffer), the server falls back to the normalauth_ok+readyflow as iflast_seqwere absent.
Server → Client (success)
{
"type": "auth_ok",
"payload": {
"user": {
"id": 1, "username": "alex",
"avatar": "uuid.png", "role": "admin"
},
"server_name": "My Server",
"motd": "Welcome!"
}
}
Server → Client (failure)
{ "type": "auth_error", "payload": { "message": "Invalid or expired token" } }
Connection is closed by server after auth_error.
Heartbeat Monitoring
The server tracks lastActivity per client connection. Any
incoming WebSocket message (including pings) resets the timer.
Clients inactive for >90 seconds are disconnected by the server.
The client sends a WebSocket ping every 30 seconds, which is sufficient to keep the connection alive under normal conditions.
Chat Messages
Send Message (Client → Server)
{
"type": "chat_send",
"id": "req-uuid",
"payload": {
"channel_id": 5,
"content": "Hello everyone!",
"reply_to": null,
"attachments": ["upload-uuid-1"]
}
}
Message Broadcast (Server → Client)
{
"type": "chat_message",
"payload": {
"id": 1042, "channel_id": 5,
"user": {
"id": 1, "username": "alex",
"avatar": "uuid.png"
},
"content": "Hello everyone!",
"reply_to": null,
"attachments": [{
"id": "upload-uuid-1",
"filename": "photo.jpg",
"size": 204800,
"mime": "image/jpeg",
"url": "/files/upload-uuid-1"
}],
"timestamp": "2026-03-14T10:30:00Z"
}
}
Send Ack (Server → Client)
{
"type": "chat_send_ok",
"id": "req-uuid",
"payload": {
"message_id": 1042,
"timestamp": "2026-03-14T10:30:00Z"
}
}
Edit Message (Client → Server)
{
"type": "chat_edit",
"id": "req-uuid",
"payload": {
"message_id": 1042,
"content": "Hello everyone! (edited)"
}
}
Edit Broadcast (Server → Client)
{
"type": "chat_edited",
"payload": {
"message_id": 1042,
"channel_id": 5,
"content": "Hello everyone! (edited)",
"edited_at": "2026-03-14T10:31:00Z"
}
}
Delete Message (Client → Server)
{ "type": "chat_delete", "id": "req-uuid", "payload": { "message_id": 1042 } }
Delete Broadcast (Server → Client)
{ "type": "chat_deleted", "payload": { "message_id": 1042, "channel_id": 5 } }
Reaction Add/Remove (Client → Server)
{ "type": "reaction_add", "payload": { "message_id": 1042, "emoji": "👍" } }
{ "type": "reaction_remove", "payload": { "message_id": 1042, "emoji": "👍" } }
Reaction Broadcast (Server → Client)
{
"type": "reaction_update",
"payload": {
"message_id": 1042,
"channel_id": 5,
"emoji": "👍",
"user_id": 1,
"action": "add"
}
}
Typing Indicators
Client → Server (throttle to 1 per 3 seconds)
{ "type": "typing_start", "payload": { "channel_id": 5 } }
Server → Client (broadcast to channel members)
{
"type": "typing",
"payload": {
"channel_id": 5,
"user_id": 1,
"username": "alex"
}
}
Client-side: show indicator for 5 seconds, reset on new typing event from same user.
Presence
Presence Client → Server
{ "type": "presence_update", "payload": { "status": "online" } }
Status values: online, idle, dnd, offline
Presence Server → Client (broadcast)
{ "type": "presence", "payload": { "user_id": 1, "status": "online" } }
Server auto-sets idle after 10 minutes of no WebSocket activity.
Channel Updates
Server → Client (on channel created/edited/deleted/reordered)
{
"type": "channel_create",
"payload": {
"id": 8, "name": "gaming",
"type": "text",
"category": "Hangout", "position": 3
}
}
{
"type": "channel_update",
"payload": {
"id": 8, "name": "gaming-talk",
"position": 4
}
}
{ "type": "channel_delete", "payload": { "id": 8 } }
Channel types: text, voice, announcement
Voice Signaling
Join Voice Channel (Client → Server)
{ "type": "voice_join", "payload": { "channel_id": 10 } }
Server → Client (voice state updates, broadcast to channel)
{
"type": "voice_state",
"payload": {
"channel_id": 10, "user_id": 1,
"username": "alex",
"muted": false, "deafened": false,
"speaking": false,
"camera": false, "screenshare": false
}
}
Voice User Left (Server → Client)
{ "type": "voice_leave", "payload": { "channel_id": 10, "user_id": 1 } }
voice_token (Server → Client)
Sent after a successful voice_join. Contains the LiveKit access token
and server URL for the client to connect directly to LiveKit.
{
"type": "voice_token",
"payload": {
"channel_id": 10,
"token": "eyJhbGciOi...",
"url": "ws://localhost:7880"
}
}
channel_id(number) — the voice channel joinedtoken(string) — LiveKit JWT access tokenurl(string) — LiveKit WebSocket URL (e.g.ws://localhost:7880)
Voice Config (Server → Client, sent after voice_join acceptance)
{
"type": "voice_config",
"payload": {
"channel_id": 10, "quality": "medium", "bitrate": 64000,
"max_users": 50
}
}
Client uses bitrate to configure the Opus encoder. Other fields are
informational for UI.
Voice Control (Client → Server)
{ "type": "voice_mute", "payload": { "muted": true } }
{ "type": "voice_deafen", "payload": { "deafened": true } }
Voice Camera / Screenshare (Client → Server)
{ "type": "voice_camera", "payload": { "enabled": true } }
{ "type": "voice_screenshare", "payload": { "enabled": true } }
Requires USE_VIDEO (bit 11) or SHARE_SCREEN (bit 12) permission.
Rate limit: 2/sec per user.
Migration Notes (LiveKit transition)
threshold_modeandtop_speakersfields have been removed fromvoice_config. LiveKit handles audio mixing and speaker selection internally.- Active speaker detection (
voice_speakers) is no longer a server→client WebSocket message. Speaker detection is handled client-side via LiveKit SDK events (ParticipantEvent.IsSpeakingChanged).
Member Updates
Server → Client
{
"type": "member_join",
"payload": {
"user": {
"id": 5, "username": "newuser",
"avatar": null, "role": "member"
}
}
}
{ "type": "member_leave", "payload": { "user_id": 5 } }
{ "type": "member_update", "payload": { "user_id": 5, "role": "moderator" } }
{ "type": "member_ban", "payload": { "user_id": 5 } }
Server Restart
Restart Server → Client
{
"type": "server_restart",
"payload": {
"reason": "update",
"delay_seconds": 5
}
}
reason(string): Why the server is restarting. Currently only"update".delay_seconds(integer): How many seconds until the server shuts down.
Client behavior: Display a banner ("Server restarting..."), then auto-reconnect after the delay expires.
Initial State (sent after auth_ok)
Ready Server → Client
{
"type": "ready",
"payload": {
"channels": [
{
"id": 1, "name": "general",
"type": "text", "category": "Main",
"position": 0, "unread_count": 3,
"last_message_id": 1040
},
{
"id": 10, "name": "voice-chat",
"type": "voice", "category": "Main",
"position": 1
}
],
"members": [
{
"id": 1, "username": "alex",
"avatar": "uuid.png",
"role": "admin", "status": "online"
},
{
"id": 2, "username": "jordan",
"avatar": null,
"role": "member", "status": "idle"
}
],
"voice_states": [
{ "channel_id": 10, "user_id": 2, "muted": false, "deafened": false }
],
"roles": [
{
"id": 1, "name": "Owner",
"color": "#E74C3C",
"permissions": 2147483647
},
{
"id": 2, "name": "Admin",
"color": "#F39C12",
"permissions": 1073741823
},
{
"id": 3, "name": "Moderator",
"color": "#3498DB",
"permissions": 1048575
},
{ "id": 4, "name": "Member", "color": null, "permissions": 7779 }
]
}
}
Message History (REST, not WebSocket)
Fetched via REST API, not WebSocket, to keep the WS connection lean.
GET /api/v1/channels/{id}/messages?before={msg_id}&limit=50
Error Format
Any request that fails returns:
{
"type": "error",
"id": "original-req-uuid",
"payload": {
"code": "FORBIDDEN",
"message": "No permission to post here"
}
}
Error codes: FORBIDDEN, NOT_FOUND, RATE_LIMITED, INVALID_INPUT,
SERVER_ERROR, CHANNEL_FULL, VOICE_ERROR
Rate Limits
- Chat messages: 10/sec per user
- Typing events: 1/3sec per user per channel
- Presence updates: 1/10sec per user
- Reactions: 5/sec per user
- Voice signaling: 20/sec per user
- Voice camera/screenshare: 2/sec per user
Server sends a standard error message with code RATE_LIMITED and retry_after in seconds:
{"type": "error", "payload": {"code": "RATE_LIMITED", "message": "...", "retry_after": 5}}