Interstellar Voice Chat

Real-time proximity voice chat for Among Us. A single BepInEx plugin DLL plus a standalone relay server.

Project Structure

AmongUs-VoiceChat/
├── Interstellar.sln
├── Interstellar.Client/       # BepInEx plugin — audio engine + game integration
│   ├── Network/               #   WebRTC connection
│   ├── Routing/               #   Audio routing graph (mixer, filters, panner)
│   ├── VoiceChat/             #   Mic, Speaker, VCRoom
│   ├── Game/                  #   Among Us integration (HUD, config, settings UI, popups)
│   ├── Patches/               #   Harmony patches (splash screens, join overlay)
│   ├── Android/               #   Android mic/speaker via Starlight
│   ├── NAudio/                #   Audio buffer providers
│   ├── Resources/             #   Sprites
│   └── InterstellarPlugin.cs  #   Entry point
├── Interstellar.Messages/     # Shared WebSocket / WebRTC message protocol
├── Interstellar.Server/       # Voice relay server (WebSocket + WebRTC)
├── docker-compose.yml         # Docker: Server + Coturn
├── Dockerfile
├── nuget.config
├── turnserver.conf
└── .github/workflows/build.yml

Build

Prerequisites: .NET 8 SDK (server), .NET 6 SDK (plugin), 7-Zip (Windows — dependency packaging)

# Plugin (two-pass: first compile, second embeds dependencies)
dotnet build Interstellar.Client/Interstellar.Client.csproj -c Release
dotnet build Interstellar.Client/Interstellar.Client.csproj -c Release

# Server
dotnet publish Interstellar.Server/Interstellar.Server.csproj -c Release -o ./server

Install: Copy Interstellar.Client.dll and its dependencies from bin/Release/net6.0/ into BepInEx/plugins/.

Server

Running

# Basic
dotnet run --project Interstellar.Server 0.0.0.0:22021 --optimal-players 12

# With Coturn
dotnet run --project Interstellar.Server 0.0.0.0:22021 \
  --optimal-players 12 \
  --coturn turn:your-server.com:3478 \
  --coturn-user interstellar --coturn-pass yourpassword

# With WSS (TLS)
dotnet run --project Interstellar.Server 0.0.0.0:22021 \
  -s /path/to/cert.pfx -p password

CLI Reference

Interstellar.Server <bind_address> [options]

  -s, --secure <path>          WSS certificate (.pfx)
  -p, --password <pwd>         Certificate password
  -t, --coturn <url>           Coturn TURN URL
  --coturn-user <user>         TURN username
  --coturn-pass <pass>         TURN password
  -op, --optimal-players <n>   Optimal player count (triggers capacity warning)

Dashboard

Visit http://your-server:22021/.

Endpoint	Response
GET /	HTML dashboard (optimal players, rooms, clients, VC URL, Coturn status)
GET /health	{"status":"ok"}
GET /stats	{"status":"ok","clients":5,"rooms":2,"optimalPlayers":12,"serverUrl":"http://...","coturn":true,"wss":false}
GET /api/rooms	Full room list with player details, optimalPlayers, and serverUrl

Player Capacity

When --optimal-players is set, the server broadcasts player counts to all connected clients. If the total online count reaches the optimal value, a full-screen popup warns players and suggests switching servers or sponsoring an upgrade.

Voice Server Matching

The plugin resolves each Among Us region to a voice server URL through three layers, applied in priority order:

Priority	Source	Behavior
1	ForceVoiceServer	Overrides everything — all regions use a single VC server
2	CustomServerListJson	Overrides API entries with the same name (case-insensitive)
3	API	Fetched from https://api.amongusclub.cn/Interstellar/ServerList.json at startup
Fallback	ws://47.122.116.50:22021	Used when no match is found

API and custom server format:

{
  "servers": [
    {
      "name": "Modded Asia (MAS)",
      "address": "au-as.duikbo.at",
      "port": 443,
      "vc": "ws://47.122.116.50:22021",
      "vcLocation": "Hong Kong"
    }
  ]
}

• name — Among Us region name (exact, case-insensitive match)
• vc — WebSocket URL of the voice server for that region (optional; falls back to default)
• vcLocation — Human-readable label shown in the HUD instead of the IP
• Custom servers override API entries with the same name. If the API is disabled, only the custom list is used.

Plugin Features

Keyboard Shortcuts

Key	Function
F1	Toggle VC settings window
M	Cycle mic mode: Global → Impostor Radio → Muted
N	Toggle speaker on/off

Settings UI

Press F1 or click the VC button in the game's Options menu to open the settings window. It has two sections:

• Personal — Microphone device, speaker device, mic volume, master volume (device selection hidden on Android)
• Room (host only) — Max chat distance, Walls Block Sound, Only Hear In Sight, Impostor Hear Ghosts, Only Ghosts Can Talk, Hear In Vent, Vent Private Chat, Comms Sabotage Mutes, Camera Can Hear, Impostor Private Radio, Only Meeting / Lobby

Non-host players see room settings grayed out. All changes are persisted to the BepInEx config file.

Join Overlay & Capacity Popup

On joining a game, a fade-in overlay shows the voice server address and current player count. When the server hits its optimal capacity, a full-screen popup warns players.

Plugin Config

BepInEx/config/com.voicechatplugin.cn.cfg:

[VoiceChat]
MicrophoneDevice =
SpeakerDevice =
ServerAddress =             # Override VC server (blank = auto-match)
MasterVolume = 1.0
MicVolume = 1.0

[VoiceChat.Server]
UseApiServerList = true
CustomServerListJson =      # One-line JSON; overrides API entries with the same name
ForceVoiceServerEnabled = false
ForceVoiceServerUrl =       # VC WebSocket URL when force is enabled

[VoiceChat.Room]
MaxChatDistance = 6
WallsBlockSound = true
OnlyHearInSight = false
ImpostorHearGhosts = false
OnlyGhostsCanTalk = false
HearInVent = true
VentPrivateChat = false
CommsSabDisables = true
CameraCanHear = true
ImpostorPrivateRadio = false
OnlyMeetingOrLobby = false

Docker

export COTURN_URL=turn:your-server.com:3478
export COTURN_USER=interstellar
export COTURN_PASS=your_secure_password

# Edit turnserver.conf user= line, then:
docker compose up -d

Port	Protocol	Service
22021	TCP	Interstellar WebSocket
3478	TCP+UDP	Coturn STUN/TURN
5349	TCP+UDP	Coturn TURN TLS
49152-49252	UDP	Coturn relay

CI

GitHub Actions builds on push:

• Server — single-file self-contained binaries for linux-x64, linux-arm64, win-x64, osx-x64
• Client — plugin DLL
• Tag pushes trigger a draft GitHub Release with all artifacts.

Credits

• Interstellar — voice server framework by Dolly
• Nebula on the Ship — architecture reference
• AOU Team — Starlight Android Audio API
• NAudio — .NET audio library
• SIPSorcery — .NET WebRTC library
• Coturn — TURN/STUN server

License

MIT