Lightweight, self-hosted voice and text chat application.
LAIR is a cross-platform communication system built from the ground up in C++. The networking architecture and code conventions draw heavily from id Software's Quake III Arena — the same battle-tested patterns that powered online gaming for millions of players.
This project implements real-time text chat over TCP with a custom binary protocol, extensible command system, and terminal-based interface. Voice communication over UDP and a Qt-based GUI are planned.
- Real-time TCP text chat supporting multiple concurrent clients
- Custom binary message protocol with type-safe serialization
- Terminal User Interface built on ncurses with Unicode box drawing
- Tab-based navigation: Chat, Private Messages, Friends, Settings
- Extensible command system with hash table lookups
- Non-blocking network I/O with configurable timeouts
- Color-coded message types: chat, system, error
- Scrollable chat history with timestamp display
- Dynamic terminal resize handling
- Cross-platform socket abstraction (POSIX/Win32)
- UDP voice communication with Opus codec
- Qt-based graphical interface (ImGui integration prepared)
- End-to-end encryption
- Private messaging system
- Friends list with presence tracking
- Channel/room support
- User authentication and persistence
- Server-side moderation tools
LAIR follows a client-server model using TCP for reliable text delivery:
┌─────────────────────────────────────────┐
│ lair_server │
│ ┌───────────────────────────────────┐ │
│ │ Client Manager │ │
│ │ ┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐ │ │
│ │ │ C0 │ │ C1 │ │ C2 │ │ ... │ │ │
│ │ └──┬──┘ └──┬──┘ └──┬──┘ └──┬──┘ │ │
│ └─────┼──────┼──────┼──────┼───────┘ │
└────────┼──────┼──────┼──────┼──────────┘
│ │ │ │
TCP │ │ │ │
│ │ │ │
┌──────────────┴──────┴──────┴──────┴──────────────┐
│ │
┌────────┴────────┐ ┌──────────┴────────┐
│ lair_client │ │ lair_client │
│ ┌───────────┐ │ │ ┌─────────────┐ │
│ │ TUI │ │ │ │ Qt GUI │ │
│ │ ncurses │ │ │ │ (planned) │ │
│ └───────────┘ │ │ └─────────────┘ │
└─────────────────┘ └───────────────────┘
Communication uses a compact binary protocol optimized for low overhead:
┌──────────┬────────────────────────────────┐
│ Byte 0 │ Bytes 1..N │
├──────────┼────────────────────────────────┤
│ Type │ Type-specific payload │
└──────────┴────────────────────────────────┘
Message types include connection handshake, user management, text chat, channel operations, and voice data frames.
The client implements an id Tech-style command system with:
- Tokenizer for parsing command strings
- Hash table for O(1) command lookups
- Command buffer for queued execution
- Extensible registration API
| Command | Description |
|---|---|
/connect <host> [port] |
Connect to a server |
/disconnect |
Disconnect from current server |
/name <username> |
Set or change username |
/users |
List connected users |
/help |
Show available commands |
/quit |
Exit the application |
| Key | Action |
|---|---|
Tab |
Next tab |
Shift+Tab |
Previous tab |
Ctrl+D |
Scroll up (older messages) |
Ctrl+U |
Scroll down (newer messages) |
Escape |
Quit prompt |
- OS: macOS, Linux, Windows
- Compiler: C++17 compatible (GCC, Clang, MSVC)
- Build: CMake 3.16+
- Dependencies: ncurses (TUI client)
# Install dependencies
brew install cmake ncurses
# Build
mkdir build && cd build
cmake ..
make
# Run server
./lair_server
# Run client (separate terminal)
./lair_client# Install dependencies
sudo apt install build-essential cmake libncurses-dev
# Build
mkdir build && cd build
cmake ..
make# Install dependencies
sudo pacman -S cmake ncurses
# Build
mkdir build && cd build
cmake ..
makecmake -DLAIR_BUILD_SERVER=ON .. # Build server (default: ON)
cmake -DLAIR_BUILD_CLIENT_TUI=ON .. # Build TUI client (default: ON)
cmake -DLAIR_BUILD_CLIENT=OFF .. # Build GUI client (default: OFF)lair/
├── code/
│ ├── lcommon/ # Shared library
│ │ ├── l_shared.h # Type definitions and constants
│ │ ├── msg.cpp/h # Message serialization
│ │ ├── cmd.cpp/h # Command system
│ │ └── common.cpp # Utility functions
│ ├── server/ # Server implementation
│ │ ├── sv_main.cpp # Server main loop
│ │ └── server.h # Server structures
│ ├── client/ # Client networking
│ │ ├── cl_main.cpp # Client connection handling
│ │ └── cl_commands.cpp
│ ├── client-tui/ # ncurses interface
│ │ ├── tui.cpp # Terminal UI implementation
│ │ └── tui.h # UI state and drawing
│ ├── posix/ # POSIX network/system layer
│ └── win32/ # Windows network/system layer
├── deps/
│ ├── cjson/ # JSON parsing
│ └── imgui/ # GUI toolkit (future)
├── CMakeLists.txt
└── LICENSE
- Non-blocking sockets with select-based multiplexing
- Configurable connection timeouts
- Automatic reconnection handling
- Platform abstraction for POSIX and Win32
- Connection:
CONNECT,CONNECT_ACCEPTED,CONNECT_DENIED,DISCONNECT - Users:
USERJOIN,USERLEAVE,USERINFO,USERLIST,USERKICK,USERBAN - Chat:
CHAT,CHAT_PRIVATE,CHAT_CHANNEL,CHAT_SERVER - Channels:
CHANNELLIST,CHANNELJOIN,CHANNELLEAVE,CHANNELCREATE - Voice:
VOICEDATA,VOICESTART,VOICESTOP(planned)
- Max clients: 256
- Max message length: 4096 bytes
- Max username: 32 characters
- Default port: 7331
Active development. Core text chat functionality complete. Voice and GUI in progress.
GNU General Public License v2.0. See LICENSE for details.
This license was chosen for compatibility with code patterns derived from Quake III Arena.
Contributions welcome. Follow the existing code style:
- Tabs for indentation
- Spaces around operators and after keywords
- Opening braces on same line
- Descriptive function and variable names
Architecture and conventions influenced by id Software's Quake III Arena source code release.
Karlo Siric