Rondevu Client

🌐 Simple WebRTC signaling client with username-based discovery

TypeScript/JavaScript client for Rondevu, providing WebRTC signaling with username claiming, service publishing/discovery, and efficient batch polling.

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

• Username Claiming: Secure ownership with Ed25519 signatures
• Anonymous Users: Auto-generated anonymous usernames for quick testing
• Service Publishing: Publish services with multiple offers for connection pooling
• Service Discovery: Direct lookup, random discovery, or paginated search
• Efficient Batch Polling: Single endpoint for answers and ICE candidates (50% fewer requests)
• Semantic Version Matching: Compatible version resolution (chat:1.0.0 matches any 1.x.x)
• TypeScript: Full type safety and autocomplete
• Keypair Management: Generate or reuse Ed25519 keypairs
• Automatic Signatures: All authenticated requests signed automatically

Installation

npm install @xtr-dev/rondevu-client

Quick Start

Publishing a Service (Offerer)

import { Rondevu } from '@xtr-dev/rondevu-client'

// 1. Initialize (with username or anonymous)
const rondevu = new Rondevu({
  apiUrl: 'https://api.ronde.vu',
  username: 'alice'  // Or omit for anonymous username
})

await rondevu.initialize()  // Generates keypair automatically

// 2. Claim username (optional - anonymous users auto-claim)
await rondevu.claimUsername()

// 3. Create WebRTC offer
const pc = new RTCPeerConnection({
  iceServers: [{ urls: 'stun:stun.l.google.com:19302' }]
})

const dc = pc.createDataChannel('chat')

const offer = await pc.createOffer()
await pc.setLocalDescription(offer)

// 4. Publish service
const service = await rondevu.publishService({
  serviceFqn: 'chat:1.0.0@alice',
  offers: [{ sdp: offer.sdp }],
  ttl: 300000
})

const offerId = service.offers[0].offerId

// 5. Poll for answer and ICE candidates (combined)
let lastPollTimestamp = 0
const pollInterval = setInterval(async () => {
  const result = await rondevu.pollOffers(lastPollTimestamp)

  // Check for answer
  if (result.answers.length > 0) {
    const answer = result.answers.find(a => a.offerId === offerId)
    if (answer) {
      await pc.setRemoteDescription({ type: 'answer', sdp: answer.sdp })
      lastPollTimestamp = answer.answeredAt
    }
  }

  // Process ICE candidates
  if (result.iceCandidates[offerId]) {
    const candidates = result.iceCandidates[offerId]
      .filter(c => c.role === 'answerer')  // Only answerer's candidates

    for (const item of candidates) {
      await pc.addIceCandidate(new RTCIceCandidate(item.candidate))
      lastPollTimestamp = Math.max(lastPollTimestamp, item.createdAt)
    }
  }
}, 1000)

// 6. Send ICE candidates
pc.onicecandidate = (event) => {
  if (event.candidate) {
    rondevu.addOfferIceCandidates(
      'chat:1.0.0@alice',
      offerId,
      [event.candidate.toJSON()]
    )
  }
}

// 7. Handle messages
dc.onmessage = (event) => {
  console.log('Received:', event.data)
}

dc.onopen = () => {
  dc.send('Hello from Alice!')
}

Connecting to a Service (Answerer)

import { Rondevu } from '@xtr-dev/rondevu-client'

// 1. Initialize
const rondevu = new Rondevu({
  apiUrl: 'https://api.ronde.vu',
  username: 'bob'
})

await rondevu.initialize()
await rondevu.claimUsername()

// 2. Get service offer
const serviceData = await rondevu.getService('chat:1.0.0@alice')

// 3. Create peer connection
const pc = new RTCPeerConnection({
  iceServers: [{ urls: 'stun:stun.l.google.com:19302' }]
})

// 4. Set remote offer and create answer
await pc.setRemoteDescription({ type: 'offer', sdp: serviceData.sdp })

const answer = await pc.createAnswer()
await pc.setLocalDescription(answer)

// 5. Send answer
await rondevu.postOfferAnswer(
  serviceData.serviceFqn,
  serviceData.offerId,
  answer.sdp
)

// 6. Send ICE candidates
pc.onicecandidate = (event) => {
  if (event.candidate) {
    rondevu.addOfferIceCandidates(
      serviceData.serviceFqn,
      serviceData.offerId,
      [event.candidate.toJSON()]
    )
  }
}

// 7. Poll for ICE candidates
let lastIceTimestamp = 0
const iceInterval = setInterval(async () => {
  const result = await rondevu.getOfferIceCandidates(
    serviceData.serviceFqn,
    serviceData.offerId,
    lastIceTimestamp
  )

  for (const item of result.candidates) {
    if (item.candidate) {
      await pc.addIceCandidate(new RTCIceCandidate(item.candidate))
      lastIceTimestamp = item.createdAt
    }
  }
}, 1000)

// 8. Handle data channel
pc.ondatachannel = (event) => {
  const dc = event.channel

  dc.onmessage = (event) => {
    console.log('Received:', event.data)
  }

  dc.onopen = () => {
    dc.send('Hello from Bob!')
  }
}

API Reference

Rondevu Class

Main class for all Rondevu operations.

import { Rondevu } from '@xtr-dev/rondevu-client'

const rondevu = new Rondevu({
  apiUrl: string,          // Signaling server URL
  username?: string,       // Optional: your username (auto-generates anonymous if omitted)
  keypair?: Keypair,       // Optional: reuse existing keypair
  cryptoAdapter?: CryptoAdapter  // Optional: platform-specific crypto (defaults to WebCryptoAdapter)
})

Platform Support (Browser & Node.js)

The client supports both browser and Node.js environments using crypto adapters:

Browser (default):

import { Rondevu } from '@xtr-dev/rondevu-client'

// WebCryptoAdapter is used by default - no configuration needed
const rondevu = new Rondevu({
  apiUrl: 'https://api.ronde.vu',
  username: 'alice'
})

Node.js (19+ or 18 with --experimental-global-webcrypto):

import { Rondevu, NodeCryptoAdapter } from '@xtr-dev/rondevu-client'

const rondevu = new Rondevu({
  apiUrl: 'https://api.ronde.vu',
  username: 'alice',
  cryptoAdapter: new NodeCryptoAdapter()
})

await rondevu.initialize()

Note: Node.js support requires:

• Node.js 19+ (crypto.subtle available globally), OR
• Node.js 18 with --experimental-global-webcrypto flag
• WebRTC implementation like wrtc or node-webrtc for RTCPeerConnection

Custom Crypto Adapter:

import { CryptoAdapter, Keypair } from '@xtr-dev/rondevu-client'

class CustomCryptoAdapter implements CryptoAdapter {
  async generateKeypair(): Promise<Keypair> { /* ... */ }
  async signMessage(message: string, privateKey: string): Promise<string> { /* ... */ }
  async verifySignature(message: string, signature: string, publicKey: string): Promise<boolean> { /* ... */ }
  bytesToBase64(bytes: Uint8Array): string { /* ... */ }
  base64ToBytes(base64: string): Uint8Array { /* ... */ }
  randomBytes(length: number): Uint8Array { /* ... */ }
}

const rondevu = new Rondevu({
  apiUrl: 'https://api.ronde.vu',
  cryptoAdapter: new CustomCryptoAdapter()
})

Initialization

// Initialize (generates keypair if not provided, auto-claims anonymous usernames)
await rondevu.initialize(): Promise<void>

Username Management

// Claim username with Ed25519 signature
await rondevu.claimUsername(): Promise<void>

// Check if username is claimed (checks server)
await rondevu.isUsernameClaimed(): Promise<boolean>

// Get username
rondevu.getUsername(): string

// Get public key
rondevu.getPublicKey(): string | null

// Get keypair (for backup/storage)
rondevu.getKeypair(): Keypair | null

Service Publishing

// Publish service with offers
await rondevu.publishService({
  serviceFqn: string,  // e.g., 'chat:1.0.0@alice'
  offers: Array<{ sdp: string }>,
  ttl?: number         // Optional: milliseconds (default: 300000)
}): Promise<Service>

Service Discovery

// Direct lookup by FQN (with username)
await rondevu.getService('chat:1.0.0@alice'): Promise<ServiceOffer>

// Random discovery (without username)
await rondevu.discoverService('chat:1.0.0'): Promise<ServiceOffer>

// Paginated discovery (returns multiple offers)
await rondevu.discoverServices(
  'chat:1.0.0',  // serviceVersion
  10,            // limit
  0              // offset
): Promise<{ services: ServiceOffer[], count: number, limit: number, offset: number }>

WebRTC Signaling

// Post answer SDP
await rondevu.postOfferAnswer(
  serviceFqn: string,
  offerId: string,
  sdp: string
): Promise<{ success: boolean, offerId: string }>

// Get answer SDP (offerer polls this - deprecated, use pollOffers instead)
await rondevu.getOfferAnswer(
  serviceFqn: string,
  offerId: string
): Promise<{ sdp: string, offerId: string, answererId: string, answeredAt: number } | null>

// Combined polling for answers and ICE candidates (RECOMMENDED for offerers)
await rondevu.pollOffers(since?: number): Promise<{
  answers: Array<{
    offerId: string
    serviceId?: string
    answererId: string
    sdp: string
    answeredAt: number
  }>
  iceCandidates: Record<string, Array<{
    candidate: any
    role: 'offerer' | 'answerer'
    peerId: string
    createdAt: number
  }>>
}>

// Add ICE candidates
await rondevu.addOfferIceCandidates(
  serviceFqn: string,
  offerId: string,
  candidates: RTCIceCandidateInit[]
): Promise<{ count: number, offerId: string }>

// Get ICE candidates (with polling support)
await rondevu.getOfferIceCandidates(
  serviceFqn: string,
  offerId: string,
  since: number = 0
): Promise<{ candidates: IceCandidate[], offerId: string }>

RondevuSignaler Class

Higher-level signaling abstraction with automatic polling and event listeners.

import { RondevuSignaler } from '@xtr-dev/rondevu-client'

const signaler = new RondevuSignaler(
  rondevu: Rondevu,
  service: string,      // Service FQN without username (e.g., 'chat:1.0.0')
  host?: string,        // Optional: target username for answerer
  pollingConfig?: {
    initialInterval?: number      // Default: 500ms
    maxInterval?: number           // Default: 5000ms
    backoffMultiplier?: number     // Default: 1.5
    maxRetries?: number            // Default: 50
    jitter?: boolean               // Default: true
  }
)

Offerer Side

// Set offer (automatically starts polling for answer and ICE)
await signaler.setOffer(offer: RTCSessionDescriptionInit): Promise<void>

// Listen for answer
const unbind = signaler.addAnswerListener((answer) => {
  console.log('Received answer:', answer)
})

// Listen for ICE candidates
signaler.addListener((candidate) => {
  console.log('Received ICE candidate:', candidate)
})

// Send ICE candidate
await signaler.addIceCandidate(candidate: RTCIceCandidate): Promise<void>

Answerer Side

// Listen for offer (automatically searches for service)
const unbind = signaler.addOfferListener((offer) => {
  console.log('Received offer:', offer)
})

// Set answer (automatically starts polling for ICE)
await signaler.setAnswer(answer: RTCSessionDescriptionInit): Promise<void>

// Send ICE candidate
await signaler.addIceCandidate(candidate: RTCIceCandidate): Promise<void>

// Listen for ICE candidates
signaler.addListener((candidate) => {
  console.log('Received ICE candidate:', candidate)
})

Cleanup

// Stop all polling and cleanup
signaler.dispose(): void

RondevuAPI Class

Low-level HTTP API client (used internally by Rondevu class).

import { RondevuAPI } from '@xtr-dev/rondevu-client'

const api = new RondevuAPI(
  baseUrl: string,
  username: string,
  keypair: Keypair
)

// Check username
await api.checkUsername(username: string): Promise<{
  available: boolean
  publicKey?: string
  claimedAt?: number
  expiresAt?: number
}>

// Claim username
await api.claimUsername(
  username: string,
  publicKey: string,
  signature: string,
  message: string
): Promise<{ success: boolean, username: string }>

// ... (all other HTTP endpoints)

Cryptographic Helpers

// Generate Ed25519 keypair
const keypair = await RondevuAPI.generateKeypair(): Promise<Keypair>

// Sign message
const signature = await RondevuAPI.signMessage(
  message: string,
  privateKey: string
): Promise<string>

// Verify signature
const valid = await RondevuAPI.verifySignature(
  message: string,
  signature: string,
  publicKey: string
): Promise<boolean>

Types

interface Keypair {
  publicKey: string   // Base64-encoded Ed25519 public key
  privateKey: string  // Base64-encoded Ed25519 private key
}

interface Service {
  serviceId: string
  offers: ServiceOffer[]
  username: string
  serviceFqn: string
  createdAt: number
  expiresAt: number
}

interface ServiceOffer {
  offerId: string
  sdp: string
  createdAt: number
  expiresAt: number
}

interface IceCandidate {
  candidate: RTCIceCandidateInit
  createdAt: number
}

interface PollingConfig {
  initialInterval?: number     // Default: 500ms
  maxInterval?: number          // Default: 5000ms
  backoffMultiplier?: number    // Default: 1.5
  maxRetries?: number           // Default: 50
  jitter?: boolean              // Default: true
}

Advanced Usage

Anonymous Username

// Auto-generate anonymous username (format: anon-{timestamp}-{random})
const rondevu = new Rondevu({
  apiUrl: 'https://api.ronde.vu'
  // No username provided - will generate anonymous username
})

await rondevu.initialize()  // Auto-claims anonymous username

console.log(rondevu.getUsername())  // e.g., "anon-lx2w34-a3f501"

// Anonymous users behave exactly like regular users
await rondevu.publishService({
  serviceFqn: `chat:1.0.0@${rondevu.getUsername()}`,
  offers: [{ sdp: offerSdp }]
})

Persistent Keypair

// Save keypair and username to localStorage
const rondevu = new Rondevu({
  apiUrl: 'https://api.ronde.vu',
  username: 'alice'
})

await rondevu.initialize()
await rondevu.claimUsername()

// Save for later
localStorage.setItem('rondevu-username', rondevu.getUsername())
localStorage.setItem('rondevu-keypair', JSON.stringify(rondevu.getKeypair()))

// Load on next session
const savedUsername = localStorage.getItem('rondevu-username')
const savedKeypair = JSON.parse(localStorage.getItem('rondevu-keypair'))

const rondevu2 = new Rondevu({
  apiUrl: 'https://api.ronde.vu',
  username: savedUsername,
  keypair: savedKeypair
})

await rondevu2.initialize()  // Reuses keypair

Service Discovery

// Get a random available service
const service = await rondevu.discoverService('chat:1.0.0')
console.log('Discovered:', service.username)

// Get multiple services (paginated)
const result = await rondevu.discoverServices('chat:1.0.0', 10, 0)
console.log(`Found ${result.count} services:`)
result.services.forEach(s => console.log(`  - ${s.username}`))

Multiple Concurrent Offers

// Publish service with multiple offers for connection pooling
const offers = []
const connections = []

for (let i = 0; i < 5; i++) {
  const pc = new RTCPeerConnection(rtcConfig)
  const dc = pc.createDataChannel('chat')
  const offer = await pc.createOffer()
  await pc.setLocalDescription(offer)

  offers.push({ sdp: offer.sdp })
  connections.push({ pc, dc })
}

const service = await rondevu.publishService({
  serviceFqn: 'chat:1.0.0@alice',
  offers,
  ttl: 300000
})

// Each offer can be answered independently
console.log(`Published ${service.offers.length} offers`)

Custom Polling Configuration

const signaler = new RondevuSignaler(
  rondevu,
  'chat:1.0.0',
  'alice',
  {
    initialInterval: 1000,    // Start at 1 second
    maxInterval: 10000,       // Max 10 seconds
    backoffMultiplier: 2,     // Double each time
    maxRetries: 30,           // Stop after 30 retries
    jitter: true              // Add randomness
  }
)

Platform Support

Modern Browsers

Works out of the box - no additional setup needed.

Node.js 18+

Native fetch is available, but WebRTC requires polyfills:

npm install wrtc

import { RTCPeerConnection, RTCSessionDescription, RTCIceCandidate } from 'wrtc'

// Use wrtc implementations
const pc = new RTCPeerConnection()

Username Rules

• Format: Lowercase alphanumeric + dash (a-z, 0-9, -)
• Length: 3-32 characters
• Pattern: ^[a-z0-9][a-z0-9-]*[a-z0-9]$
• Validity: 365 days from claim/last use
• Ownership: Secured by Ed25519 public key signature

Service FQN Format

• Format: service:version@username
• Service: Lowercase alphanumeric + dash (e.g., chat, video-call)
• Version: Semantic versioning (e.g., 1.0.0, 2.1.3)
• Username: Claimed username
• Example: chat:1.0.0@alice

Examples

See the demo for a complete working example with React UI.

Migration from v0.3.x

v0.4.0 removes high-level abstractions and uses manual WebRTC setup:

Removed:

• ServiceHost class (use manual WebRTC + publishService())
• ServiceClient class (use manual WebRTC + getService())
• RTCDurableConnection class (use native WebRTC APIs)
• RondevuService class (merged into Rondevu)

Added:

• pollOffers() - Combined polling for answers and ICE candidates
• RondevuSignaler - Simplified signaling with automatic polling

Migration Example:

// Before (v0.3.x) - ServiceHost
const host = new ServiceHost({
  service: 'chat@1.0.0',
  rondevuService: service
})
await host.start()

// After (v0.4.0) - Manual setup
const pc = new RTCPeerConnection()
const dc = pc.createDataChannel('chat')
const offer = await pc.createOffer()
await pc.setLocalDescription(offer)

await rondevu.publishService({
  serviceFqn: 'chat:1.0.0@alice',
  offers: [{ sdp: offer.sdp }]
})

License

MIT