P2P Video Calling App

A simple, personal-use voice and video calling application built with WebRTC. Users can create a room and share a link for instant, browser-based communication without authentication.

🏗 Architecture

High-Level Architecture

The application follows a client-server model with a signaling mechanism to establish Peer-to-Peer (P2P) connections.

graph TD
    UserA[User A - Browser] <--> Server[Express Server + WebSocket Signaling]
    UserB[User B - Browser] <--> Server
    UserA -- WebRTC P2P (Audio/Video) --- UserB
    Server <--> DB[(PostgreSQL)]

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Components

1. Frontend (React + Vite): Handles the user interface, media device access (Camera/Mic), and WebRTC state management.
2. Backend (Node.js + Express): Provides REST API for room management and hosts the WebSocket signaling server.
3. Signaling Server (WebSocket): Facilitates the exchange of "handshake" information (SDP offers/answers and ICE candidates) between peers.
4. Database (PostgreSQL): Stores room metadata for session persistence.
5. WebRTC: Enables direct media streaming between browsers once the handshake is complete.

Sequence Diagram: Call Establishment

sequenceDiagram
    participant A as User A (Initiator)
    participant S as Signaling Server
    participant B as User B (Joiner)

    Note over A,B: Signaling via WebSocket
    A->>S: Create Room / Join Room
    B->>S: Join Room (via shared link)
    S->>A: peer-joined
    A->>A: Create WebRTC Offer
    A->>S: send offer (SDP)
    S->>B: forward offer
    B->>B: Create WebRTC Answer
    B->>S: send answer (SDP)
    S->>A: forward answer
    Note over A,B: ICE Candidate Exchange
    A->>S: send ice-candidate
    S->>B: forward candidate
    B->>S: send ice-candidate
    S->>A: forward candidate
    Note over A,B: P2P Connection Established
    A-->>B: Direct Video/Audio Stream

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🚀 Local Deployment Guide

Prerequisites

• Node.js: v18 or higher.
• PostgreSQL: A running instance (or use a local SQLite/Mock if modified).
• HTTPS: WebRTC requires a secure context. For local testing, localhost works, but for network access, you need SSL certificates.

1. Windows Setup

1. Clone the repository:

   git clone <your-repo-url>
   cd <repo-name>

2. Install Dependencies:

   npm install

3. Environment Variables: Create a .env file in the root:

   DATABASE_URL=postgres://user:password@localhost:5432/dbname

4. Database Push:

   npm run db:push

5. Run Development:

   npm run dev

   Access at http://localhost:5000.

2. Raspberry Pi Setup (Linux)

1. Install Node.js & Postgres:

   sudo apt update
   sudo apt install nodejs npm postgresql

2. Setup Database:

   sudo -u postgres psql -c "CREATE DATABASE vido_call;"

3. Deploy: Follow the same steps as Windows.
4. Internet Access (Important):
   • To use this over the internet, you must use a tool like Cloudflare Tunnel or Nginx with Let's Encrypt to provide an https:// URL.
   • WebRTC will fail on mobile devices if served over plain http://.

🛠 Tech Stack

• Frontend: React, Tailwind CSS, Framer Motion, Lucide Icons.
• Backend: Node.js, Express, ws (WebSockets).
• Database: Drizzle ORM + PostgreSQL.
• Real-time: WebRTC (Native Browser API) + Google STUN servers.