💬 Real-Time Chat & Video Meeting Engine

A comprehensive real-time communication platform combining instant messaging and high-quality video conferencing. Built with Angular 20 and NestJS utilizing Native WebSockets.

🚀 Key Features

• Instant Messaging: Real-time text exchange, typing indicators (typing), and user presence tracking (presence).
• Video Meetings (WebRTC): Group and P2P calls using Mesh architecture (direct peer-to-peer connection).
• Native WebSockets: Built on pure ws protocol without heavy abstractions (like Socket.io), ensuring maximum performance and low latency.
• F5-Resilience: Meeting states are persisted on the server. Sessions are automatically restored upon page refresh or reconnection.
• Catch-up Notifications: Users instantly receive invitations to ongoing meetings upon logging into the application.

📡 Socket Events Protocol

The system uses a single communication channel for all event types. Message format: { "event": "event_name", "data": { ... } }.

📝 Chat & Presence

Event	Description
message	Sending and receiving new text messages.
typing	Notification that the interlocutor is typing.
presence	User online/offline status updates.

🎥 Video Meetings (WebRTC)

Event	Description
start_meeting	Initiates a new meeting session.
meeting_invitation	Broadcasts invitations (statuses: active/inactive).
join_meeting	Signal from a participant ready to establish a connection.
video-signal	Relay for WebRTC signals (Offer, Answer, ICE Candidates).
meeting_user_joined	Notifies the host that a participant has entered the room.
meeting_user_left	Notifies about a participant leaving or connection loss.
leave_meeting	Manual exit from the current call.
stop_meeting	(Host only) Terminates the meeting and revokes invitations.
meeting_ended	Signal to all participants that the room is closed.
get_room_info	Requests the current room state upon page initialization.
room_info_response	Server response with meeting data and online participants list.

🛠 Tech Stack

• Frontend: Angular 20 (Signals, DestroyRef, Standalone Components).
• Backend: NestJS, Native WebSockets (@nestjs/platform-ws).
• Protocol: WebRTC (Signaling via native sockets).

💻 Getting Started

# Install dependencies
npm install

# Run in development mode
npm run start

🗺 Roadmap

• Redis Integration: Move active meeting storage to Redis for horizontal scaling and high availability.
• Smart Cleanup: Implement an auto-termination timer if no active participants remain in the call.
• Screen Sharing: Enable screen broadcasting using the getDisplayMedia API.
• Reconnection Grace Period: Implement a short timeout for host disconnections to prevent instant call termination during network flickers.

⚠️ Technical Notes

• Resource Cleanup: When a call ends, the closeAllConnections() method stops all MediaStreamTracks and closes RTCPeerConnection ports.
• Local Stream: The local video preview is always muted to prevent acoustic feedback loops (echo).
• Browser Support: Optimized for Chromium and Firefox. Safari support is currently experimental/unsupported.