Scalable WebRTC signaling server with cryptographic username claiming, service publishing with semantic versioning, and efficient offer/answer exchange via JSON-RPC interface.

Related repositories:

@xtr-dev/rondevu-client - TypeScript client library (npm)
@xtr-dev/rondevu-server - HTTP signaling server (npm, live)
@xtr-dev/rondevu-demo - Interactive demo (live)

Features

RPC Interface: Single endpoint for all operations with batching support
Username Claiming: Cryptographic username ownership with Ed25519 signatures (365-day validity, auto-renewed on use)
Service Publishing: Service:version@username naming (e.g., chat:1.0.0@alice)
Service Discovery: Random and paginated discovery for finding services without knowing usernames
Semantic Versioning: Compatible version matching (chat:1.0.0 matches any 1.x.x)
Signature-Based Authentication: All authenticated requests use Ed25519 signatures
Complete WebRTC Signaling: Offer/answer exchange and ICE candidate relay
Batch Operations: Execute multiple operations in a single HTTP request
Dual Storage: SQLite (Node.js/Docker) and Cloudflare D1 (Workers) backends

Architecture

Username Claiming → Service Publishing → Service Discovery → WebRTC Connection

alice claims "alice" with Ed25519 signature
  ↓
alice publishes chat:1.0.0@alice with offers
  ↓
bob queries chat:1.0.0@alice (direct) or chat:1.0.0 (discovery) → gets offer SDP
  ↓
bob posts answer SDP → WebRTC connection established
  ↓
ICE candidates exchanged via server relay

Quick Start

Node.js:

npm install && npm start

Docker:

docker build -t rondevu . && docker run -p 3000:3000 -e STORAGE_PATH=:memory: rondevu

Cloudflare Workers:

npx wrangler deploy

RPC Interface

All API calls are made to POST /rpc with JSON-RPC format.

Request Format

Single method call:

{
  "method": "getUser",
  "message": "getUser:alice:1733404800000",
  "signature": "base64-encoded-signature",
  "params": {
    "username": "alice"
  }
}

Batch calls:

[
  {
    "method": "getUser",
    "message": "getUser:alice:1733404800000",
    "signature": "base64-encoded-signature",
    "params": { "username": "alice" }
  },
  {
    "method": "claimUsername",
    "message": "claim:bob:1733404800000",
    "signature": "base64-encoded-signature",
    "params": {
      "username": "bob",
      "publicKey": "base64-encoded-public-key"
    }
  }
]

Response Format

Single response:

{
  "success": true,
  "result": { /* method-specific data */ }
}

Error response:

{
  "success": false,
  "error": "Error message"
}

Batch responses: Array of responses matching request array order.

Core Methods

Username Management

// Check username availability
POST /rpc
{
  "method": "getUser",
  "params": { "username": "alice" }
}

// Claim username (requires signature)
POST /rpc
{
  "method": "claimUsername",
  "message": "claim:alice:1733404800000",
  "signature": "base64-signature",
  "params": {
    "username": "alice",
    "publicKey": "base64-public-key"
  }
}

Service Publishing

// Publish service (requires signature)
POST /rpc
{
  "method": "publishService",
  "message": "publishService:alice:chat:1.0.0@alice:1733404800000",
  "signature": "base64-signature",
  "params": {
    "serviceFqn": "chat:1.0.0@alice",
    "offers": [{ "sdp": "webrtc-offer-sdp" }],
    "ttl": 300000
  }
}

Service Discovery

// Get specific service
POST /rpc
{
  "method": "getService",
  "params": { "serviceFqn": "chat:1.0.0@alice" }
}

// Random discovery
POST /rpc
{
  "method": "getService",
  "params": { "serviceFqn": "chat:1.0.0" }
}

// Paginated discovery
POST /rpc
{
  "method": "getService",
  "params": {
    "serviceFqn": "chat:1.0.0",
    "limit": 10,
    "offset": 0
  }
}

WebRTC Signaling

// Answer offer (requires signature)
POST /rpc
{
  "method": "answerOffer",
  "message": "answer:bob:offer-id:1733404800000",
  "signature": "base64-signature",
  "params": {
    "serviceFqn": "chat:1.0.0@alice",
    "offerId": "offer-id",
    "sdp": "webrtc-answer-sdp"
  }
}

// Add ICE candidates (requires signature)
POST /rpc
{
  "method": "addIceCandidates",
  "params": {
    "serviceFqn": "chat:1.0.0@alice",
    "offerId": "offer-id",
    "candidates": [{ /* RTCIceCandidateInit */ }]
  }
}

// Poll for answers and ICE candidates (requires signature)
POST /rpc
{
  "method": "poll",
  "params": { "since": 1733404800000 }
}

Configuration

Quick reference for common environment variables:

Variable	Default	Description
`PORT`	`3000`	Server port (Node.js/Docker)
`CORS_ORIGINS`	`*`	Comma-separated allowed origins
`STORAGE_PATH`	`./rondevu.db`	SQLite database path (use `:memory:` for in-memory)

📚 See ADVANCED.md for complete configuration reference.

Documentation

📚 ADVANCED.md - Comprehensive guide including:

Complete RPC method reference with examples
Full configuration options
Database schema documentation
Security implementation details
Migration guides

Security

All authenticated operations require Ed25519 signatures:

Message Format: {method}:{username}:{context}:{timestamp}
Signature: Base64-encoded Ed25519 signature of the message
Replay Protection: Timestamps must be within 5 minutes
Username Ownership: Verified via public key signature

See ADVANCED.md for detailed security documentation.

License

MIT