Release v0.9.2: Fix service pool ICE candidate collection

Fixed critical timing issue where ICE candidates were generated before
the handler was attached, causing them to be lost:

- Set up onicecandidate handler BEFORE setLocalDescription()
- Collect candidates in array while waiting for offer ID
- Send all pending candidates once offer ID is available
- Add detailed logging for service pool ICE candidates
- Log candidate type (host/srflx/relay) for debugging

This ensures all ICE candidates are captured and sent to the signaling
server, and provides visibility into what types of candidates are being
generated (especially important for diagnosing TURN relay issues).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

MIGRATION.md

@@ -0,0 +1,547 @@
+# Migration Guide: v0.8.x → v0.9.0
+
+This guide helps you migrate from Rondevu Client v0.8.x to v0.9.0.
+
+## Overview
+
+v0.9.0 is a **breaking change** that completely replaces low-level APIs with high-level durable connections featuring automatic reconnection and message queuing.
+
+### What's New
+
+✅ **Durable Connections**: Automatic reconnection on network drops
+✅ **Message Queuing**: Messages sent during disconnections are queued and flushed on reconnect
+✅ **Durable Channels**: RTCDataChannel wrappers that survive connection drops
+✅ **TTL Auto-Refresh**: Services automatically republish before expiration
+✅ **Simplified API**: Direct methods on main client instead of nested APIs
+
+### What's Removed
+
+❌ **Low-level APIs**: `client.services.*`, `client.discovery.*`, `client.createPeer()` no longer exported
+❌ **Manual Connection Management**: No need to handle WebRTC peer lifecycle manually
+❌ **Service Handles**: Replaced with DurableService instances
+
+## Breaking Changes
+
+### 1. Service Exposure
+
+#### v0.8.x (Old)
+```typescript
+import { Rondevu } from '@xtr-dev/rondevu-client';
+
+const client = new Rondevu();
+await client.register();
+
+const handle = await client.services.exposeService({
+  username: 'alice',
+  privateKey: keypair.privateKey,
+  serviceFqn: 'chat@1.0.0',
+  isPublic: true,
+  handler: (channel, peer) => {
+    channel.onmessage = (e) => {
+      console.log('Received:', e.data);
+      channel.send(`Echo: ${e.data}`);
+    };
+  }
+});
+
+// Unpublish
+await handle.unpublish();
+```
+
+#### v0.9.0 (New)
+```typescript
+import { Rondevu } from '@xtr-dev/rondevu-client';
+
+const client = new Rondevu();
+await client.register();
+
+const service = await client.exposeService({
+  username: 'alice',
+  privateKey: keypair.privateKey,
+  serviceFqn: 'chat@1.0.0',
+  isPublic: true,
+  poolSize: 10,  // NEW: Handle multiple concurrent connections
+  handler: (channel, connectionId) => {
+    // NEW: DurableChannel with event emitters
+    channel.on('message', (data) => {
+      console.log('Received:', data);
+      channel.send(`Echo: ${data}`);
+    });
+  }
+});
+
+// NEW: Start the service
+await service.start();
+
+// NEW: Stop the service
+await service.stop();
+```
+
+**Key Differences:**
+- `client.services.exposeService()` → `client.exposeService()`
+- Returns `DurableService` instead of `ServiceHandle`
+- Handler receives `DurableChannel` instead of `RTCDataChannel`
+- Handler receives `connectionId` string instead of `RondevuPeer`
+- DurableChannel uses `.on('message', ...)` instead of `.onmessage = ...`
+- Must call `service.start()` to begin accepting connections
+- Use `service.stop()` instead of `handle.unpublish()`
+
+### 2. Connecting to Services
+
+#### v0.8.x (Old)
+```typescript
+// Connect by username + FQN
+const { peer, channel } = await client.discovery.connect(
+  'alice',
+  'chat@1.0.0'
+);
+
+channel.onmessage = (e) => {
+  console.log('Received:', e.data);
+};
+
+channel.onopen = () => {
+  channel.send('Hello!');
+};
+
+peer.on('connected', () => {
+  console.log('Connected');
+});
+
+peer.on('failed', (error) => {
+  console.error('Failed:', error);
+});
+```
+
+#### v0.9.0 (New)
+```typescript
+// Connect by username + FQN
+const connection = await client.connect('alice', 'chat@1.0.0', {
+  maxReconnectAttempts: 10  // NEW: Configurable reconnection
+});
+
+// NEW: Create durable channel
+const channel = connection.createChannel('main');
+
+channel.on('message', (data) => {
+  console.log('Received:', data);
+});
+
+channel.on('open', () => {
+  channel.send('Hello!');
+});
+
+// NEW: Connection lifecycle events
+connection.on('connected', () => {
+  console.log('Connected');
+});
+
+connection.on('reconnecting', (attempt, max, delay) => {
+  console.log(`Reconnecting (${attempt}/${max})...`);
+});
+
+connection.on('failed', (error) => {
+  console.error('Failed permanently:', error);
+});
+
+// NEW: Must explicitly connect
+await connection.connect();
+```
+
+**Key Differences:**
+- `client.discovery.connect()` → `client.connect()`
+- Returns `DurableConnection` instead of `{ peer, channel }`
+- Must create channels with `connection.createChannel()`
+- Must call `connection.connect()` to establish connection
+- Automatic reconnection with configurable retry limits
+- Messages sent during disconnection are automatically queued
+
+### 3. Connecting by UUID
+
+#### v0.8.x (Old)
+```typescript
+const { peer, channel } = await client.discovery.connectByUuid('service-uuid');
+
+channel.onmessage = (e) => {
+  console.log('Received:', e.data);
+};
+```
+
+#### v0.9.0 (New)
+```typescript
+const connection = await client.connectByUuid('service-uuid', {
+  maxReconnectAttempts: 5
+});
+
+const channel = connection.createChannel('main');
+
+channel.on('message', (data) => {
+  console.log('Received:', data);
+});
+
+await connection.connect();
+```
+
+**Key Differences:**
+- `client.discovery.connectByUuid()` → `client.connectByUuid()`
+- Returns `DurableConnection` instead of `{ peer, channel }`
+- Must create channels and connect explicitly
+
+### 4. Multi-Connection Services (Offer Pooling)
+
+#### v0.8.x (Old)
+```typescript
+const handle = await client.services.exposeService({
+  username: 'alice',
+  privateKey: keypair.privateKey,
+  serviceFqn: 'chat@1.0.0',
+  poolSize: 5,
+  pollingInterval: 2000,
+  handler: (channel, peer, connectionId) => {
+    console.log(`Connection: ${connectionId}`);
+  },
+  onPoolStatus: (status) => {
+    console.log('Pool status:', status);
+  }
+});
+
+const status = handle.getStatus();
+await handle.addOffers(3);
+```
+
+#### v0.9.0 (New)
+```typescript
+const service = await client.exposeService({
+  username: 'alice',
+  privateKey: keypair.privateKey,
+  serviceFqn: 'chat@1.0.0',
+  poolSize: 5,          // SAME: Pool size
+  pollingInterval: 2000, // SAME: Polling interval
+  handler: (channel, connectionId) => {
+    console.log(`Connection: ${connectionId}`);
+  }
+});
+
+await service.start();
+
+// Get active connections
+const connections = service.getActiveConnections();
+
+// Listen for connection events
+service.on('connection', (connectionId) => {
+  console.log('New connection:', connectionId);
+});
+```
+
+**Key Differences:**
+- `onPoolStatus` callback removed (use `service.on('connection')` instead)
+- `handle.getStatus()` replaced with `service.getActiveConnections()`
+- `handle.addOffers()` removed (pool auto-manages offers)
+- Handler receives `DurableChannel` instead of `RTCDataChannel`
+
+## Feature Comparison
+
+| Feature | v0.8.x | v0.9.0 |
+|---------|--------|--------|
+| Service exposure | `client.services.exposeService()` | `client.exposeService()` |
+| Connection | `client.discovery.connect()` | `client.connect()` |
+| Connection by UUID | `client.discovery.connectByUuid()` | `client.connectByUuid()` |
+| Channel type | `RTCDataChannel` | `DurableChannel` |
+| Event handling | `.onmessage`, `.onopen`, etc. | `.on('message')`, `.on('open')`, etc. |
+| Automatic reconnection | ❌ No | ✅ Yes (configurable) |
+| Message queuing | ❌ No | ✅ Yes (during disconnections) |
+| TTL auto-refresh | ❌ No | ✅ Yes (configurable) |
+| Peer lifecycle | Manual | Automatic |
+| Connection pooling | ✅ Yes | ✅ Yes (same API) |
+
+## API Mapping
+
+### Removed Exports
+
+These are no longer exported in v0.9.0:
+
+```typescript
+// ❌ Removed
+import {
+  RondevuServices,
+  RondevuDiscovery,
+  RondevuPeer,
+  ServiceHandle,
+  PooledServiceHandle,
+  ConnectResult
+} from '@xtr-dev/rondevu-client';
+```
+
+### New Exports
+
+These are new in v0.9.0:
+
+```typescript
+// ✅ New
+import {
+  DurableConnection,
+  DurableChannel,
+  DurableService,
+  DurableConnectionState,
+  DurableChannelState,
+  DurableConnectionConfig,
+  DurableChannelConfig,
+  DurableServiceConfig,
+  DurableConnectionEvents,
+  DurableChannelEvents,
+  DurableServiceEvents,
+  ConnectionInfo,
+  ServiceInfo,
+  QueuedMessage
+} from '@xtr-dev/rondevu-client';
+```
+
+### Unchanged Exports
+
+These work the same in both versions:
+
+```typescript
+// ✅ Unchanged
+import {
+  Rondevu,
+  RondevuAuth,
+  RondevuUsername,
+  Credentials,
+  UsernameClaimResult,
+  UsernameCheckResult
+} from '@xtr-dev/rondevu-client';
+```
+
+## Configuration Options
+
+### New Connection Options
+
+v0.9.0 adds extensive configuration for automatic reconnection and message queuing:
+
+```typescript
+const connection = await client.connect('alice', 'chat@1.0.0', {
+  // Reconnection
+  maxReconnectAttempts: 10,      // default: 10
+  reconnectBackoffBase: 1000,    // default: 1000ms
+  reconnectBackoffMax: 30000,    // default: 30000ms (30 seconds)
+  reconnectJitter: 0.2,          // default: 0.2 (±20%)
+  connectionTimeout: 30000,      // default: 30000ms
+
+  // Message queuing
+  maxQueueSize: 1000,            // default: 1000 messages
+  maxMessageAge: 60000,          // default: 60000ms (1 minute)
+
+  // WebRTC
+  rtcConfig: {
+    iceServers: [...]
+  }
+});
+```
+
+### New Service Options
+
+Services can now auto-refresh TTL:
+
+```typescript
+const service = await client.exposeService({
+  username: 'alice',
+  privateKey: keypair.privateKey,
+  serviceFqn: 'chat@1.0.0',
+
+  // TTL auto-refresh (NEW)
+  ttl: 300000,              // default: 300000ms (5 minutes)
+  ttlRefreshMargin: 0.2,    // default: 0.2 (refresh at 80% of TTL)
+
+  // All connection options also apply to incoming connections
+  maxReconnectAttempts: 10,
+  maxQueueSize: 1000,
+  // ...
+});
+```
+
+## Migration Checklist
+
+- [ ] Replace `client.services.exposeService()` with `client.exposeService()`
+- [ ] Add `await service.start()` after creating service
+- [ ] Replace `handle.unpublish()` with `service.stop()`
+- [ ] Replace `client.discovery.connect()` with `client.connect()`
+- [ ] Replace `client.discovery.connectByUuid()` with `client.connectByUuid()`
+- [ ] Create channels with `connection.createChannel()` instead of receiving them directly
+- [ ] Add `await connection.connect()` to establish connection
+- [ ] Update handlers from `(channel, peer, connectionId?)` to `(channel, connectionId)`
+- [ ] Replace `.onmessage` with `.on('message', ...)`
+- [ ] Replace `.onopen` with `.on('open', ...)`
+- [ ] Replace `.onclose` with `.on('close', ...)`
+- [ ] Replace `.onerror` with `.on('error', ...)`
+- [ ] Add reconnection event handlers (`connection.on('reconnecting', ...)`)
+- [ ] Review and configure reconnection options if needed
+- [ ] Review and configure message queue limits if needed
+- [ ] Update TypeScript imports to use new types
+- [ ] Test automatic reconnection behavior
+- [ ] Test message queuing during disconnections
+
+## Common Migration Patterns
+
+### Pattern 1: Simple Echo Service
+
+#### Before (v0.8.x)
+```typescript
+await client.services.exposeService({
+  username: 'alice',
+  privateKey: keypair.privateKey,
+  serviceFqn: 'echo@1.0.0',
+  handler: (channel) => {
+    channel.onmessage = (e) => {
+      channel.send(`Echo: ${e.data}`);
+    };
+  }
+});
+```
+
+#### After (v0.9.0)
+```typescript
+const service = await client.exposeService({
+  username: 'alice',
+  privateKey: keypair.privateKey,
+  serviceFqn: 'echo@1.0.0',
+  handler: (channel) => {
+    channel.on('message', (data) => {
+      channel.send(`Echo: ${data}`);
+    });
+  }
+});
+
+await service.start();
+```
+
+### Pattern 2: Connection with Error Handling
+
+#### Before (v0.8.x)
+```typescript
+try {
+  const { peer, channel } = await client.discovery.connect('alice', 'chat@1.0.0');
+
+  channel.onopen = () => {
+    channel.send('Hello!');
+  };
+
+  peer.on('failed', (error) => {
+    console.error('Connection failed:', error);
+    // Manual reconnection logic here
+  });
+} catch (error) {
+  console.error('Failed to connect:', error);
+}
+```
+
+#### After (v0.9.0)
+```typescript
+const connection = await client.connect('alice', 'chat@1.0.0', {
+  maxReconnectAttempts: 5
+});
+
+const channel = connection.createChannel('main');
+
+channel.on('open', () => {
+  channel.send('Hello!');
+});
+
+connection.on('reconnecting', (attempt, max, delay) => {
+  console.log(`Reconnecting (${attempt}/${max}) in ${delay}ms`);
+});
+
+connection.on('failed', (error) => {
+  console.error('Connection failed permanently:', error);
+});
+
+try {
+  await connection.connect();
+} catch (error) {
+  console.error('Initial connection failed:', error);
+}
+```
+
+### Pattern 3: Multi-User Chat Server
+
+#### Before (v0.8.x)
+```typescript
+const connections = new Map();
+
+await client.services.exposeService({
+  username: 'alice',
+  privateKey: keypair.privateKey,
+  serviceFqn: 'chat@1.0.0',
+  poolSize: 10,
+  handler: (channel, peer, connectionId) => {
+    connections.set(connectionId, channel);
+
+    channel.onmessage = (e) => {
+      // Broadcast to all
+      for (const [id, ch] of connections) {
+        if (id !== connectionId) {
+          ch.send(e.data);
+        }
+      }
+    };
+
+    channel.onclose = () => {
+      connections.delete(connectionId);
+    };
+  }
+});
+```
+
+#### After (v0.9.0)
+```typescript
+const channels = new Map();
+
+const service = await client.exposeService({
+  username: 'alice',
+  privateKey: keypair.privateKey,
+  serviceFqn: 'chat@1.0.0',
+  poolSize: 10,
+  handler: (channel, connectionId) => {
+    channels.set(connectionId, channel);
+
+    channel.on('message', (data) => {
+      // Broadcast to all
+      for (const [id, ch] of channels) {
+        if (id !== connectionId) {
+          ch.send(data);
+        }
+      }
+    });
+
+    channel.on('close', () => {
+      channels.delete(connectionId);
+    });
+  }
+});
+
+await service.start();
+
+// Optional: Track connections
+service.on('connection', (connectionId) => {
+  console.log(`User ${connectionId} joined`);
+});
+
+service.on('disconnection', (connectionId) => {
+  console.log(`User ${connectionId} left`);
+});
+```
+
+## Benefits of Migration
+
+1. **Reliability**: Automatic reconnection handles network hiccups transparently
+2. **Simplicity**: No need to manage WebRTC peer lifecycle manually
+3. **Durability**: Messages sent during disconnections are queued and delivered when connection restores
+4. **Uptime**: Services automatically refresh TTL before expiration
+5. **Type Safety**: Better TypeScript types with DurableChannel event emitters
+6. **Debugging**: Queue size monitoring, connection state tracking, and detailed events
+
+## Getting Help
+
+If you encounter issues during migration:
+1. Check the [README](./README.md) for complete API documentation
+2. Review the examples for common patterns
+3. Open an issue on [GitHub](https://github.com/xtr-dev/rondevu-client/issues)

package-lock.json

@@ -1,20 +1,30 @@
 {
   "name": "@xtr-dev/rondevu-client",
-  "version": "0.7.0",
+  "version": "0.9.2",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@xtr-dev/rondevu-client",
-      "version": "0.7.0",
+      "version": "0.9.2",
       "license": "MIT",
       "dependencies": {
+        "@noble/ed25519": "^3.0.0",
         "@xtr-dev/rondevu-client": "^0.5.1"
       },
       "devDependencies": {
         "typescript": "^5.9.3"
       }
     },
+    "node_modules/@noble/ed25519": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/@noble/ed25519/-/ed25519-3.0.0.tgz",
+      "integrity": "sha512-QyteqMNm0GLqfa5SoYbSC3+Pvykwpn95Zgth4MFVSMKBB75ELl9tX1LAVsN4c3HXOrakHsF2gL4zWDAYCcsnzg==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://paulmillr.com/funding/"
+      }
+    },
     "node_modules/@xtr-dev/rondevu-client": {
       "version": "0.5.1",
       "resolved": "https://registry.npmjs.org/@xtr-dev/rondevu-client/-/rondevu-client-0.5.1.tgz",

package.json

@@ -1,7 +1,7 @@
 {
   "name": "@xtr-dev/rondevu-client",
-  "version": "0.7.0",
+  "version": "0.9.2",
-  "description": "TypeScript client for Rondevu topic-based peer discovery and signaling server",
+  "description": "TypeScript client for Rondevu with durable WebRTC connections, automatic reconnection, and message queuing",
   "type": "module",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
@@ -27,6 +27,6 @@
     "README.md"
   ],
   "dependencies": {
-    "@xtr-dev/rondevu-client": "^0.5.1"
+    "@noble/ed25519": "^3.0.0"
   }
 }

src/auth.ts

@@ -29,6 +29,8 @@ export class RondevuAuth {
 
   /**
    * Register a new peer and receive credentials
+   * Generates a cryptographically random peer ID (128-bit)
+   * @throws Error if registration fails
    */
   async register(): Promise<Credentials> {
     const response = await this.fetchFn(`${this.baseUrl}/register`, {

src/bloom.ts

@@ -1,83 +0,0 @@
-// Declare Buffer for Node.js compatibility
-declare const Buffer: any;
-
-/**
- * Simple bloom filter implementation for peer ID exclusion
- * Uses multiple hash functions for better distribution
- */
-export class BloomFilter {
-  private bits: Uint8Array;
-  private size: number;
-  private numHashes: number;
-
-  constructor(size: number = 1024, numHashes: number = 3) {
-    this.size = size;
-    this.numHashes = numHashes;
-    this.bits = new Uint8Array(Math.ceil(size / 8));
-  }
-
-  /**
-   * Add a peer ID to the filter
-   */
-  add(peerId: string): void {
-    for (let i = 0; i < this.numHashes; i++) {
-      const hash = this.hash(peerId, i);
-      const index = hash % this.size;
-      const byteIndex = Math.floor(index / 8);
-      const bitIndex = index % 8;
-      this.bits[byteIndex] |= 1 << bitIndex;
-    }
-  }
-
-  /**
-   * Test if peer ID might be in the filter
-   */
-  test(peerId: string): boolean {
-    for (let i = 0; i < this.numHashes; i++) {
-      const hash = this.hash(peerId, i);
-      const index = hash % this.size;
-      const byteIndex = Math.floor(index / 8);
-      const bitIndex = index % 8;
-      if (!(this.bits[byteIndex] & (1 << bitIndex))) {
-        return false;
-      }
-    }
-    return true;
-  }
-
-  /**
-   * Get raw bits for transmission
-   */
-  toBytes(): Uint8Array {
-    return this.bits;
-  }
-
-  /**
-   * Convert to base64 for URL parameters
-   */
-  toBase64(): string {
-    // Convert Uint8Array to regular array then to string
-    const binaryString = String.fromCharCode(...Array.from(this.bits));
-    // Use btoa for browser, or Buffer for Node.js
-    if (typeof btoa !== 'undefined') {
-      return btoa(binaryString);
-    } else if (typeof Buffer !== 'undefined') {
-      return Buffer.from(this.bits).toString('base64');
-    } else {
-      // Fallback: manual base64 encoding
-      throw new Error('No base64 encoding available');
-    }
-  }
-
-  /**
-   * Simple hash function (FNV-1a variant)
-   */
-  private hash(str: string, seed: number): number {
-    let hash = 2166136261 ^ seed;
-    for (let i = 0; i < str.length; i++) {
-      hash ^= str.charCodeAt(i);
-      hash += (hash << 1) + (hash << 4) + (hash << 7) + (hash << 8) + (hash << 24);
-    }
-    return hash >>> 0;
-  }
-}

src/client.ts

@@ -1,208 +0,0 @@
-import {
-  RondevuClientOptions,
-  CreateOfferRequest,
-  CreateOfferResponse,
-  AnswerRequest,
-  AnswerResponse,
-  PollRequest,
-  PollOffererResponse,
-  PollAnswererResponse,
-  VersionResponse,
-  HealthResponse,
-  ErrorResponse,
-  Side,
-} from './types.js';
-
-/**
- * HTTP API client for Rondevu peer signaling server
- */
-export class RondevuAPI {
-  private readonly baseUrl: string;
-  private readonly fetchImpl: typeof fetch;
-
-  /**
-   * Creates a new Rondevu API client instance
-   * @param options - Client configuration options
-   */
-  constructor(options: RondevuClientOptions) {
-    this.baseUrl = options.baseUrl.replace(/\/$/, ''); // Remove trailing slash
-    this.fetchImpl = options.fetch || globalThis.fetch.bind(globalThis);
-  }
-
-  /**
-   * Makes an HTTP request to the Rondevu server
-   */
-  private async request<T>(
-    endpoint: string,
-    options: RequestInit = {}
-  ): Promise<T> {
-    const url = `${this.baseUrl}${endpoint}`;
-
-    const headers: Record<string, string> = {
-      ...(options.headers as Record<string, string>),
-    };
-
-    if (options.body) {
-      headers['Content-Type'] = 'application/json';
-    }
-
-    const response = await this.fetchImpl(url, {
-      ...options,
-      headers,
-    });
-
-    const data = await response.json();
-
-    if (!response.ok) {
-      const error = data as ErrorResponse;
-      throw new Error(error.error || `HTTP ${response.status}: ${response.statusText}`);
-    }
-
-    return data as T;
-  }
-
-  /**
-   * Gets server version information
-   *
-   * @returns Server version
-   *
-   * @example
-   * ```typescript
-   * const api = new RondevuAPI({ baseUrl: 'https://example.com' });
-   * const { version } = await api.getVersion();
-   * console.log('Server version:', version);
-   * ```
-   */
-  async getVersion(): Promise<VersionResponse> {
-    return this.request<VersionResponse>('/', {
-      method: 'GET',
-    });
-  }
-
-  /**
-   * Creates a new offer
-   *
-   * @param request - Offer details including peer ID, signaling data, and optional custom code
-   * @returns Unique offer code (UUID or custom code)
-   *
-   * @example
-   * ```typescript
-   * const api = new RondevuAPI({ baseUrl: 'https://example.com' });
-   * const { code } = await api.createOffer({
-   *   peerId: 'peer-123',
-   *   offer: signalingData,
-   *   code: 'my-custom-code' // optional
-   * });
-   * console.log('Offer code:', code);
-   * ```
-   */
-  async createOffer(request: CreateOfferRequest): Promise<CreateOfferResponse> {
-    return this.request<CreateOfferResponse>('/offer', {
-      method: 'POST',
-      body: JSON.stringify(request),
-    });
-  }
-
-  /**
-   * Sends an answer or candidate to an existing offer
-   *
-   * @param request - Answer details including offer code and signaling data
-   * @returns Success confirmation
-   *
-   * @example
-   * ```typescript
-   * const api = new RondevuAPI({ baseUrl: 'https://example.com' });
-   *
-   * // Send answer
-   * await api.sendAnswer({
-   *   code: offerCode,
-   *   answer: answerData,
-   *   side: 'answerer'
-   * });
-   *
-   * // Send candidate
-   * await api.sendAnswer({
-   *   code: offerCode,
-   *   candidate: candidateData,
-   *   side: 'offerer'
-   * });
-   * ```
-   */
-  async sendAnswer(request: AnswerRequest): Promise<AnswerResponse> {
-    return this.request<AnswerResponse>('/answer', {
-      method: 'POST',
-      body: JSON.stringify(request),
-    });
-  }
-
-  /**
-   * Polls for offer data from the other peer
-   *
-   * @param code - Offer code
-   * @param side - Which side is polling ('offerer' or 'answerer')
-   * @returns Offer data including offers, answers, and candidates
-   *
-   * @example
-   * ```typescript
-   * const api = new RondevuAPI({ baseUrl: 'https://example.com' });
-   *
-   * // Offerer polls for answer
-   * const offererData = await api.poll(offerCode, 'offerer');
-   * if (offererData.answer) {
-   *   console.log('Received answer:', offererData.answer);
-   * }
-   *
-   * // Answerer polls for offer
-   * const answererData = await api.poll(offerCode, 'answerer');
-   * console.log('Received offer:', answererData.offer);
-   * ```
-   */
-  async poll(
-    code: string,
-    side: Side
-  ): Promise<PollOffererResponse | PollAnswererResponse> {
-    const request: PollRequest = { code, side };
-    return this.request<PollOffererResponse | PollAnswererResponse>('/poll', {
-      method: 'POST',
-      body: JSON.stringify(request),
-    });
-  }
-
-  /**
-   * Checks server health and version
-   *
-   * @returns Health status, timestamp, and version
-   *
-   * @example
-   * ```typescript
-   * const api = new RondevuAPI({ baseUrl: 'https://example.com' });
-   * const health = await api.health();
-   * console.log('Server status:', health.status);
-   * console.log('Server version:', health.version);
-   * ```
-   */
-  async health(): Promise<HealthResponse> {
-    return this.request<HealthResponse>('/health', {
-      method: 'GET',
-    });
-  }
-
-  /**
-   * Ends a session by deleting the offer from the server
-   *
-   * @param code - The offer code
-   * @returns Success confirmation
-   *
-   * @example
-   * ```typescript
-   * const api = new RondevuAPI({ baseUrl: 'https://example.com' });
-   * await api.leave('my-offer-code');
-   * ```
-   */
-  async leave(code: string): Promise<{ success: boolean }> {
-    return this.request<{ success: boolean }>('/leave', {
-      method: 'POST',
-      body: JSON.stringify({ code }),
-    });
-  }
-}

src/durable/channel.ts

@@ -0,0 +1,361 @@
+/**
+ * DurableChannel - Message queueing wrapper for RTCDataChannel
+ *
+ * Provides automatic message queuing during disconnections and transparent
+ * flushing when the connection is re-established.
+ */
+
+import { EventEmitter } from '../event-emitter.js';
+import {
+  DurableChannelState
+} from './types.js';
+import type {
+  DurableChannelConfig,
+  DurableChannelEvents,
+  QueuedMessage
+} from './types.js';
+
+/**
+ * Default configuration for durable channels
+ */
+const DEFAULT_CONFIG = {
+  maxQueueSize: 1000,
+  maxMessageAge: 60000, // 1 minute
+  ordered: true,
+  maxRetransmits: undefined
+} as const;
+
+/**
+ * Durable channel that survives WebRTC peer connection drops
+ *
+ * The DurableChannel wraps an RTCDataChannel and provides:
+ * - Automatic message queuing during disconnections
+ * - Queue flushing on reconnection
+ * - Configurable queue size and message age limits
+ * - RTCDataChannel-compatible API
+ *
+ * @example
+ * ```typescript
+ * const channel = new DurableChannel('chat', connection, {
+ *   maxQueueSize: 500,
+ *   maxMessageAge: 30000
+ * });
+ *
+ * channel.on('message', (data) => {
+ *   console.log('Received:', data);
+ * });
+ *
+ * channel.on('open', () => {
+ *   channel.send('Hello!');
+ * });
+ *
+ * // Messages sent during disconnection are automatically queued
+ * channel.send('This will be queued if disconnected');
+ * ```
+ */
+export class DurableChannel extends EventEmitter<DurableChannelEvents> {
+  readonly label: string;
+  readonly config: DurableChannelConfig;
+
+  private _state: DurableChannelState;
+  private underlyingChannel?: RTCDataChannel;
+  private messageQueue: QueuedMessage[] = [];
+  private queueProcessing: boolean = false;
+  private _bufferedAmountLowThreshold: number = 0;
+
+  // Event handlers that need cleanup
+  private openHandler?: () => void;
+  private messageHandler?: (event: MessageEvent) => void;
+  private errorHandler?: (event: Event) => void;
+  private closeHandler?: () => void;
+  private bufferedAmountLowHandler?: () => void;
+
+  constructor(
+    label: string,
+    config?: DurableChannelConfig
+  ) {
+    super();
+    this.label = label;
+    this.config = { ...DEFAULT_CONFIG, ...config };
+    this._state = DurableChannelState.CONNECTING;
+  }
+
+  /**
+   * Current channel state
+   */
+  get readyState(): DurableChannelState {
+    return this._state;
+  }
+
+  /**
+   * Buffered amount from underlying channel (0 if no channel)
+   */
+  get bufferedAmount(): number {
+    return this.underlyingChannel?.bufferedAmount ?? 0;
+  }
+
+  /**
+   * Buffered amount low threshold
+   */
+  get bufferedAmountLowThreshold(): number {
+    return this._bufferedAmountLowThreshold;
+  }
+
+  set bufferedAmountLowThreshold(value: number) {
+    this._bufferedAmountLowThreshold = value;
+    if (this.underlyingChannel) {
+      this.underlyingChannel.bufferedAmountLowThreshold = value;
+    }
+  }
+
+  /**
+   * Send data through the channel
+   *
+   * If the channel is open, sends immediately. Otherwise, queues the message
+   * for delivery when the channel reconnects.
+   *
+   * @param data - Data to send
+   */
+  send(data: string | Blob | ArrayBuffer | ArrayBufferView): void {
+    if (this._state === DurableChannelState.OPEN && this.underlyingChannel) {
+      // Channel is open - send immediately
+      try {
+        this.underlyingChannel.send(data as any);
+      } catch (error) {
+        // Send failed - queue the message
+        this.enqueueMessage(data);
+        this.emit('error', error as Error);
+      }
+    } else if (this._state !== DurableChannelState.CLOSED) {
+      // Channel is not open but not closed - queue the message
+      this.enqueueMessage(data);
+    } else {
+      // Channel is closed - throw error
+      throw new Error('Cannot send on closed channel');
+    }
+  }
+
+  /**
+   * Close the channel
+   */
+  close(): void {
+    if (this._state === DurableChannelState.CLOSED ||
+        this._state === DurableChannelState.CLOSING) {
+      return;
+    }
+
+    this._state = DurableChannelState.CLOSING;
+
+    if (this.underlyingChannel) {
+      this.underlyingChannel.close();
+    }
+
+    this._state = DurableChannelState.CLOSED;
+    this.emit('close');
+  }
+
+  /**
+   * Attach to an underlying RTCDataChannel
+   *
+   * This is called when a WebRTC connection is established (or re-established).
+   * The channel will flush any queued messages and forward events.
+   *
+   * @param channel - RTCDataChannel to attach to
+   * @internal
+   */
+  attachToChannel(channel: RTCDataChannel): void {
+    // Detach from any existing channel first
+    this.detachFromChannel();
+
+    this.underlyingChannel = channel;
+
+    // Set buffered amount low threshold
+    channel.bufferedAmountLowThreshold = this._bufferedAmountLowThreshold;
+
+    // Setup event handlers
+    this.openHandler = () => {
+      this._state = DurableChannelState.OPEN;
+      this.emit('open');
+
+      // Flush queued messages
+      this.flushQueue().catch(error => {
+        this.emit('error', error);
+      });
+    };
+
+    this.messageHandler = (event: MessageEvent) => {
+      this.emit('message', event.data);
+    };
+
+    this.errorHandler = (event: Event) => {
+      this.emit('error', new Error(`Channel error: ${event.type}`));
+    };
+
+    this.closeHandler = () => {
+      if (this._state !== DurableChannelState.CLOSING &&
+          this._state !== DurableChannelState.CLOSED) {
+        // Unexpected close - transition to connecting (will reconnect)
+        this._state = DurableChannelState.CONNECTING;
+      }
+    };
+
+    this.bufferedAmountLowHandler = () => {
+      this.emit('bufferedAmountLow');
+    };
+
+    // Attach handlers
+    channel.addEventListener('open', this.openHandler);
+    channel.addEventListener('message', this.messageHandler);
+    channel.addEventListener('error', this.errorHandler);
+    channel.addEventListener('close', this.closeHandler);
+    channel.addEventListener('bufferedamountlow', this.bufferedAmountLowHandler);
+
+    // If channel is already open, trigger open event
+    if (channel.readyState === 'open') {
+      this.openHandler();
+    } else if (channel.readyState === 'connecting') {
+      this._state = DurableChannelState.CONNECTING;
+    }
+  }
+
+  /**
+   * Detach from the underlying RTCDataChannel
+   *
+   * This is called when a WebRTC connection drops. The channel remains alive
+   * and continues queuing messages.
+   *
+   * @internal
+   */
+  detachFromChannel(): void {
+    if (!this.underlyingChannel) {
+      return;
+    }
+
+    // Remove event listeners
+    if (this.openHandler) {
+      this.underlyingChannel.removeEventListener('open', this.openHandler);
+    }
+    if (this.messageHandler) {
+      this.underlyingChannel.removeEventListener('message', this.messageHandler);
+    }
+    if (this.errorHandler) {
+      this.underlyingChannel.removeEventListener('error', this.errorHandler);
+    }
+    if (this.closeHandler) {
+      this.underlyingChannel.removeEventListener('close', this.closeHandler);
+    }
+    if (this.bufferedAmountLowHandler) {
+      this.underlyingChannel.removeEventListener('bufferedamountlow', this.bufferedAmountLowHandler);
+    }
+
+    this.underlyingChannel = undefined;
+    this._state = DurableChannelState.CONNECTING;
+  }
+
+  /**
+   * Enqueue a message for later delivery
+   */
+  private enqueueMessage(data: string | Blob | ArrayBuffer | ArrayBufferView): void {
+    // Prune old messages first
+    this.pruneOldMessages();
+
+    const message: QueuedMessage = {
+      data,
+      enqueuedAt: Date.now(),
+      id: `msg-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`
+    };
+
+    this.messageQueue.push(message);
+
+    // Handle overflow
+    const maxQueueSize = this.config.maxQueueSize ?? 1000;
+    if (this.messageQueue.length > maxQueueSize) {
+      const excess = this.messageQueue.length - maxQueueSize;
+      this.messageQueue.splice(0, excess);
+      this.emit('queueOverflow', excess);
+      console.warn(
+        `DurableChannel[${this.label}]: Dropped ${excess} messages due to queue overflow`
+      );
+    }
+  }
+
+  /**
+   * Flush all queued messages through the channel
+   */
+  private async flushQueue(): Promise<void> {
+    if (this.queueProcessing || !this.underlyingChannel ||
+        this.underlyingChannel.readyState !== 'open') {
+      return;
+    }
+
+    this.queueProcessing = true;
+
+    try {
+      // Prune old messages before flushing
+      this.pruneOldMessages();
+
+      // Send all queued messages
+      while (this.messageQueue.length > 0) {
+        const message = this.messageQueue.shift();
+        if (!message) break;
+
+        try {
+          this.underlyingChannel.send(message.data as any);
+        } catch (error) {
+          // Send failed - re-queue message
+          this.messageQueue.unshift(message);
+          throw error;
+        }
+
+        // If buffer is getting full, wait for it to drain
+        if (this.underlyingChannel.bufferedAmount > 16 * 1024 * 1024) { // 16MB
+          await new Promise<void>((resolve) => {
+            const checkBuffer = () => {
+              if (!this.underlyingChannel ||
+                  this.underlyingChannel.bufferedAmount < 8 * 1024 * 1024) {
+                resolve();
+              } else {
+                setTimeout(checkBuffer, 100);
+              }
+            };
+            checkBuffer();
+          });
+        }
+      }
+    } finally {
+      this.queueProcessing = false;
+    }
+  }
+
+  /**
+   * Remove messages older than maxMessageAge from the queue
+   */
+  private pruneOldMessages(): void {
+    const maxMessageAge = this.config.maxMessageAge ?? 60000;
+    if (maxMessageAge === Infinity || maxMessageAge <= 0) {
+      return;
+    }
+
+    const now = Date.now();
+    const cutoff = now - maxMessageAge;
+
+    const originalLength = this.messageQueue.length;
+    this.messageQueue = this.messageQueue.filter(msg => msg.enqueuedAt >= cutoff);
+
+    const pruned = originalLength - this.messageQueue.length;
+    if (pruned > 0) {
+      console.warn(
+        `DurableChannel[${this.label}]: Pruned ${pruned} old messages (older than ${maxMessageAge}ms)`
+      );
+    }
+  }
+
+  /**
+   * Get the current queue size
+   *
+   * @internal
+   */
+  getQueueSize(): number {
+    return this.messageQueue.length;
+  }
+}

src/durable/connection.ts

@@ -0,0 +1,453 @@
+/**
+ * DurableConnection - WebRTC connection with automatic reconnection
+ *
+ * Manages the WebRTC peer lifecycle and automatically reconnects on
+ * connection drops with exponential backoff.
+ */
+
+import { EventEmitter } from '../event-emitter.js';
+import RondevuPeer from '../peer/index.js';
+import type { RondevuOffers } from '../offers.js';
+import { DurableChannel } from './channel.js';
+import { createReconnectionScheduler, type ReconnectionScheduler } from './reconnection.js';
+import {
+  DurableConnectionState
+} from './types.js';
+import type {
+  DurableConnectionConfig,
+  DurableConnectionEvents,
+  ConnectionInfo
+} from './types.js';
+
+/**
+ * Default configuration for durable connections
+ */
+const DEFAULT_CONFIG: Required<DurableConnectionConfig> = {
+  maxReconnectAttempts: 10,
+  reconnectBackoffBase: 1000,
+  reconnectBackoffMax: 30000,
+  reconnectJitter: 0.2,
+  connectionTimeout: 30000,
+  maxQueueSize: 1000,
+  maxMessageAge: 60000,
+  rtcConfig: {
+    iceServers: [
+      { urls: 'stun:stun.l.google.com:19302' },
+      { urls: 'stun:stun1.l.google.com:19302' }
+    ]
+  }
+};
+
+/**
+ * Durable WebRTC connection that automatically reconnects
+ *
+ * The DurableConnection manages the lifecycle of a WebRTC peer connection
+ * and provides:
+ * - Automatic reconnection with exponential backoff
+ * - Multiple durable channels that survive reconnections
+ * - Configurable retry limits and timeouts
+ * - High-level connection state events
+ *
+ * @example
+ * ```typescript
+ * const connection = new DurableConnection(
+ *   offersApi,
+ *   { username: 'alice', serviceFqn: 'chat@1.0.0' },
+ *   { maxReconnectAttempts: 5 }
+ * );
+ *
+ * connection.on('connected', () => {
+ *   console.log('Connected!');
+ * });
+ *
+ * connection.on('reconnecting', (attempt, max, delay) => {
+ *   console.log(`Reconnecting... (${attempt}/${max}, retry in ${delay}ms)`);
+ * });
+ *
+ * const channel = connection.createChannel('chat');
+ * channel.on('message', (data) => {
+ *   console.log('Received:', data);
+ * });
+ *
+ * await connection.connect();
+ * ```
+ */
+export class DurableConnection extends EventEmitter<DurableConnectionEvents> {
+  readonly connectionId: string;
+  readonly config: Required<DurableConnectionConfig>;
+  readonly connectionInfo: ConnectionInfo;
+
+  private _state: DurableConnectionState;
+  private currentPeer?: RondevuPeer;
+  private channels: Map<string, DurableChannel> = new Map();
+  private reconnectionScheduler?: ReconnectionScheduler;
+
+  // Track peer event handlers for cleanup
+  private peerConnectedHandler?: () => void;
+  private peerDisconnectedHandler?: () => void;
+  private peerFailedHandler?: (error: Error) => void;
+  private peerDataChannelHandler?: (channel: RTCDataChannel) => void;
+
+  constructor(
+    private offersApi: RondevuOffers,
+    connectionInfo: ConnectionInfo,
+    config?: DurableConnectionConfig
+  ) {
+    super();
+    this.connectionId = `conn-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
+    this.config = { ...DEFAULT_CONFIG, ...config };
+    this.connectionInfo = connectionInfo;
+    this._state = DurableConnectionState.CONNECTING;
+  }
+
+  /**
+   * Current connection state
+   */
+  getState(): DurableConnectionState {
+    return this._state;
+  }
+
+  /**
+   * Check if connection is currently connected
+   */
+  isConnected(): boolean {
+    return this._state === DurableConnectionState.CONNECTED;
+  }
+
+  /**
+   * Create a durable channel on this connection
+   *
+   * The channel will be created on the current peer connection if available,
+   * otherwise it will be created when the connection is established.
+   *
+   * @param label - Channel label
+   * @param options - RTCDataChannel init options
+   * @returns DurableChannel instance
+   */
+  createChannel(label: string, options?: RTCDataChannelInit): DurableChannel {
+    // Check if channel already exists
+    if (this.channels.has(label)) {
+      throw new Error(`Channel with label '${label}' already exists`);
+    }
+
+    // Create durable channel
+    const durableChannel = new DurableChannel(label, {
+      maxQueueSize: this.config.maxQueueSize,
+      maxMessageAge: this.config.maxMessageAge,
+      ordered: options?.ordered ?? true,
+      maxRetransmits: options?.maxRetransmits
+    });
+
+    this.channels.set(label, durableChannel);
+
+    // If we have a current peer, attach the channel
+    if (this.currentPeer && this._state === DurableConnectionState.CONNECTED) {
+      this.createAndAttachChannel(durableChannel, options);
+    }
+
+    return durableChannel;
+  }
+
+  /**
+   * Get an existing channel by label
+   */
+  getChannel(label: string): DurableChannel | undefined {
+    return this.channels.get(label);
+  }
+
+  /**
+   * Establish the initial connection
+   *
+   * @returns Promise that resolves when connected
+   */
+  async connect(): Promise<void> {
+    if (this._state !== DurableConnectionState.CONNECTING) {
+      throw new Error(`Cannot connect from state: ${this._state}`);
+    }
+
+    try {
+      await this.establishConnection();
+    } catch (error) {
+      this._state = DurableConnectionState.DISCONNECTED;
+      await this.handleDisconnection();
+      throw error;
+    }
+  }
+
+  /**
+   * Close the connection gracefully
+   */
+  async close(): Promise<void> {
+    if (this._state === DurableConnectionState.CLOSED) {
+      return;
+    }
+
+    const previousState = this._state;
+    this._state = DurableConnectionState.CLOSED;
+
+    // Cancel any ongoing reconnection
+    if (this.reconnectionScheduler) {
+      this.reconnectionScheduler.cancel();
+    }
+
+    // Close all channels
+    for (const channel of this.channels.values()) {
+      channel.close();
+    }
+
+    // Close peer connection
+    if (this.currentPeer) {
+      await this.currentPeer.close();
+      this.currentPeer = undefined;
+    }
+
+    this.emit('state', this._state, previousState);
+    this.emit('closed');
+  }
+
+  /**
+   * Establish a WebRTC connection
+   */
+  private async establishConnection(): Promise<void> {
+    // Create new peer
+    const peer = new RondevuPeer(this.offersApi, this.config.rtcConfig);
+    this.currentPeer = peer;
+
+    // Setup peer event handlers
+    this.setupPeerHandlers(peer);
+
+    // Determine connection method based on connection info
+    if (this.connectionInfo.uuid) {
+      // Connect by UUID
+      await this.connectByUuid(peer, this.connectionInfo.uuid);
+    } else if (this.connectionInfo.username && this.connectionInfo.serviceFqn) {
+      // Connect by username and service FQN
+      await this.connectByService(peer, this.connectionInfo.username, this.connectionInfo.serviceFqn);
+    } else {
+      throw new Error('Invalid connection info: must provide either uuid or (username + serviceFqn)');
+    }
+
+    // Wait for connection with timeout
+    await this.waitForConnection(peer);
+
+    // Connection established
+    this.transitionToConnected();
+  }
+
+  /**
+   * Connect to a service by UUID
+   */
+  private async connectByUuid(peer: RondevuPeer, uuid: string): Promise<void> {
+    // Get service details
+    const response = await fetch(`${this.offersApi['baseUrl']}/services/${uuid}`);
+    if (!response.ok) {
+      throw new Error(`Service not found: ${uuid}`);
+    }
+
+    const service = await response.json();
+
+    // Answer the offer
+    await peer.answer(service.offerId, service.sdp, {
+      secret: this.offersApi['credentials'].secret,
+      topics: []
+    });
+  }
+
+  /**
+   * Connect to a service by username and service FQN
+   */
+  private async connectByService(peer: RondevuPeer, username: string, serviceFqn: string): Promise<void> {
+    // Query service to get UUID
+    const response = await fetch(`${this.offersApi['baseUrl']}/index/${username}/query`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ serviceFqn })
+    });
+
+    if (!response.ok) {
+      throw new Error(`Service not found: ${username}/${serviceFqn}`);
+    }
+
+    const { uuid } = await response.json();
+
+    // Connect by UUID
+    await this.connectByUuid(peer, uuid);
+  }
+
+  /**
+   * Wait for peer connection to establish
+   */
+  private async waitForConnection(peer: RondevuPeer): Promise<void> {
+    return new Promise((resolve, reject) => {
+      const timeout = setTimeout(() => {
+        reject(new Error('Connection timeout'));
+      }, this.config.connectionTimeout);
+
+      const onConnected = () => {
+        clearTimeout(timeout);
+        peer.off('connected', onConnected);
+        peer.off('failed', onFailed);
+        resolve();
+      };
+
+      const onFailed = (error: Error) => {
+        clearTimeout(timeout);
+        peer.off('connected', onConnected);
+        peer.off('failed', onFailed);
+        reject(error);
+      };
+
+      peer.on('connected', onConnected);
+      peer.on('failed', onFailed);
+    });
+  }
+
+  /**
+   * Setup event handlers for peer
+   */
+  private setupPeerHandlers(peer: RondevuPeer): void {
+    this.peerConnectedHandler = () => {
+      // Connection established - will be handled by waitForConnection
+    };
+
+    this.peerDisconnectedHandler = () => {
+      if (this._state !== DurableConnectionState.CLOSED) {
+        this.handleDisconnection();
+      }
+    };
+
+    this.peerFailedHandler = (error: Error) => {
+      if (this._state !== DurableConnectionState.CLOSED) {
+        console.error('Peer connection failed:', error);
+        this.handleDisconnection();
+      }
+    };
+
+    this.peerDataChannelHandler = (channel: RTCDataChannel) => {
+      // Find or create durable channel
+      let durableChannel = this.channels.get(channel.label);
+
+      if (!durableChannel) {
+        // Auto-create channel for incoming data channels
+        durableChannel = new DurableChannel(channel.label, {
+          maxQueueSize: this.config.maxQueueSize,
+          maxMessageAge: this.config.maxMessageAge
+        });
+        this.channels.set(channel.label, durableChannel);
+      }
+
+      // Attach the received channel
+      durableChannel.attachToChannel(channel);
+    };
+
+    peer.on('connected', this.peerConnectedHandler);
+    peer.on('disconnected', this.peerDisconnectedHandler);
+    peer.on('failed', this.peerFailedHandler);
+    peer.on('datachannel', this.peerDataChannelHandler);
+  }
+
+  /**
+   * Transition to connected state
+   */
+  private transitionToConnected(): void {
+    const previousState = this._state;
+    this._state = DurableConnectionState.CONNECTED;
+
+    // Reset reconnection scheduler if it exists
+    if (this.reconnectionScheduler) {
+      this.reconnectionScheduler.reset();
+    }
+
+    // Attach all channels to the new peer connection
+    for (const [label, channel] of this.channels) {
+      if (this.currentPeer) {
+        this.createAndAttachChannel(channel);
+      }
+    }
+
+    this.emit('state', this._state, previousState);
+    this.emit('connected');
+  }
+
+  /**
+   * Create underlying RTCDataChannel and attach to durable channel
+   */
+  private createAndAttachChannel(
+    durableChannel: DurableChannel,
+    options?: RTCDataChannelInit
+  ): void {
+    if (!this.currentPeer) {
+      return;
+    }
+
+    // Check if peer already has this channel (received via datachannel event)
+    // If not, create it
+    const senders = (this.currentPeer.pc as any).getSenders?.() || [];
+    const existingChannel = Array.from(senders as RTCRtpSender[])
+      .map((sender) => (sender as any).channel as RTCDataChannel)
+      .find(ch => ch && ch.label === durableChannel.label);
+
+    if (existingChannel) {
+      durableChannel.attachToChannel(existingChannel);
+    } else {
+      // Create new channel on peer
+      const rtcChannel = this.currentPeer.createDataChannel(
+        durableChannel.label,
+        options
+      );
+      durableChannel.attachToChannel(rtcChannel);
+    }
+  }
+
+  /**
+   * Handle connection disconnection
+   */
+  private async handleDisconnection(): Promise<void> {
+    if (this._state === DurableConnectionState.CLOSED ||
+        this._state === DurableConnectionState.FAILED) {
+      return;
+    }
+
+    const previousState = this._state;
+    this._state = DurableConnectionState.RECONNECTING;
+
+    this.emit('state', this._state, previousState);
+    this.emit('disconnected');
+
+    // Detach all channels (but keep them alive)
+    for (const channel of this.channels.values()) {
+      channel.detachFromChannel();
+    }
+
+    // Close old peer
+    if (this.currentPeer) {
+      await this.currentPeer.close();
+      this.currentPeer = undefined;
+    }
+
+    // Create or use existing reconnection scheduler
+    if (!this.reconnectionScheduler) {
+      this.reconnectionScheduler = createReconnectionScheduler({
+        maxAttempts: this.config.maxReconnectAttempts,
+        backoffBase: this.config.reconnectBackoffBase,
+        backoffMax: this.config.reconnectBackoffMax,
+        jitter: this.config.reconnectJitter,
+        onReconnect: async () => {
+          await this.establishConnection();
+        },
+        onMaxAttemptsExceeded: (error) => {
+          const prevState = this._state;
+          this._state = DurableConnectionState.FAILED;
+          this.emit('state', this._state, prevState);
+          this.emit('failed', error, true);
+        },
+        onBeforeAttempt: (attempt, max, delay) => {
+          this.emit('reconnecting', attempt, max, delay);
+        }
+      });
+    }
+
+    // Schedule reconnection
+    this.reconnectionScheduler.schedule();
+  }
+}

src/durable/reconnection.ts

@@ -0,0 +1,200 @@
+/**
+ * Reconnection utilities for durable connections
+ *
+ * This module provides utilities for managing reconnection logic with
+ * exponential backoff and jitter.
+ */
+
+/**
+ * Calculate exponential backoff delay with jitter
+ *
+ * @param attempt - Current attempt number (0-indexed)
+ * @param base - Base delay in milliseconds
+ * @param max - Maximum delay in milliseconds
+ * @param jitter - Jitter factor (0-1), e.g., 0.2 for ±20%
+ * @returns Delay in milliseconds with jitter applied
+ *
+ * @example
+ * ```typescript
+ * calculateBackoff(0, 1000, 30000, 0.2) // ~1000ms ± 20%
+ * calculateBackoff(1, 1000, 30000, 0.2) // ~2000ms ± 20%
+ * calculateBackoff(2, 1000, 30000, 0.2) // ~4000ms ± 20%
+ * calculateBackoff(5, 1000, 30000, 0.2) // ~30000ms ± 20% (capped at max)
+ * ```
+ */
+export function calculateBackoff(
+  attempt: number,
+  base: number,
+  max: number,
+  jitter: number
+): number {
+  // Calculate exponential delay: base * 2^attempt
+  const exponential = base * Math.pow(2, attempt);
+
+  // Cap at maximum
+  const capped = Math.min(exponential, max);
+
+  // Apply jitter: ± (jitter * capped)
+  const jitterAmount = capped * jitter;
+  const randomJitter = (Math.random() * 2 - 1) * jitterAmount;
+
+  // Return delay with jitter, ensuring it's not negative
+  return Math.max(0, capped + randomJitter);
+}
+
+/**
+ * Configuration for reconnection scheduler
+ */
+export interface ReconnectionSchedulerConfig {
+  /** Maximum number of reconnection attempts */
+  maxAttempts: number;
+
+  /** Base delay for exponential backoff */
+  backoffBase: number;
+
+  /** Maximum delay between attempts */
+  backoffMax: number;
+
+  /** Jitter factor for randomizing delays */
+  jitter: number;
+
+  /** Callback invoked for each reconnection attempt */
+  onReconnect: () => Promise<void>;
+
+  /** Callback invoked when max attempts exceeded */
+  onMaxAttemptsExceeded: (error: Error) => void;
+
+  /** Optional callback invoked before each attempt */
+  onBeforeAttempt?: (attempt: number, maxAttempts: number, delay: number) => void;
+}
+
+/**
+ * Reconnection scheduler state
+ */
+export interface ReconnectionScheduler {
+  /** Current attempt number */
+  attempt: number;
+
+  /** Whether scheduler is active */
+  active: boolean;
+
+  /** Schedule next reconnection attempt */
+  schedule: () => void;
+
+  /** Cancel scheduled reconnection */
+  cancel: () => void;
+
+  /** Reset attempt counter */
+  reset: () => void;
+}
+
+/**
+ * Create a reconnection scheduler
+ *
+ * @param config - Scheduler configuration
+ * @returns Reconnection scheduler instance
+ *
+ * @example
+ * ```typescript
+ * const scheduler = createReconnectionScheduler({
+ *   maxAttempts: 10,
+ *   backoffBase: 1000,
+ *   backoffMax: 30000,
+ *   jitter: 0.2,
+ *   onReconnect: async () => {
+ *     await connect();
+ *   },
+ *   onMaxAttemptsExceeded: (error) => {
+ *     console.error('Failed to reconnect:', error);
+ *   },
+ *   onBeforeAttempt: (attempt, max, delay) => {
+ *     console.log(`Reconnecting in ${delay}ms (${attempt}/${max})...`);
+ *   }
+ * });
+ *
+ * // Start reconnection
+ * scheduler.schedule();
+ *
+ * // Cancel reconnection
+ * scheduler.cancel();
+ * ```
+ */
+export function createReconnectionScheduler(
+  config: ReconnectionSchedulerConfig
+): ReconnectionScheduler {
+  let attempt = 0;
+  let active = false;
+  let timer: ReturnType<typeof setTimeout> | undefined;
+
+  const schedule = () => {
+    // Cancel any existing timer
+    if (timer) {
+      clearTimeout(timer);
+      timer = undefined;
+    }
+
+    // Check if max attempts exceeded
+    if (attempt >= config.maxAttempts) {
+      active = false;
+      config.onMaxAttemptsExceeded(
+        new Error(`Max reconnection attempts exceeded (${config.maxAttempts})`)
+      );
+      return;
+    }
+
+    // Calculate delay
+    const delay = calculateBackoff(
+      attempt,
+      config.backoffBase,
+      config.backoffMax,
+      config.jitter
+    );
+
+    // Notify before attempt
+    if (config.onBeforeAttempt) {
+      config.onBeforeAttempt(attempt + 1, config.maxAttempts, delay);
+    }
+
+    // Mark as active
+    active = true;
+
+    // Schedule reconnection
+    timer = setTimeout(async () => {
+      attempt++;
+      try {
+        await config.onReconnect();
+        // Success - reset scheduler
+        attempt = 0;
+        active = false;
+      } catch (error) {
+        // Failure - schedule next attempt
+        schedule();
+      }
+    }, delay);
+  };
+
+  const cancel = () => {
+    if (timer) {
+      clearTimeout(timer);
+      timer = undefined;
+    }
+    active = false;
+  };
+
+  const reset = () => {
+    cancel();
+    attempt = 0;
+  };
+
+  return {
+    get attempt() {
+      return attempt;
+    },
+    get active() {
+      return active;
+    },
+    schedule,
+    cancel,
+    reset
+  };
+}

src/durable/service.ts

@@ -0,0 +1,329 @@
+/**
+ * DurableService - Service with automatic TTL refresh
+ *
+ * Manages service publishing with automatic reconnection for incoming
+ * connections and TTL auto-refresh to prevent expiration.
+ */
+
+import { EventEmitter } from '../event-emitter.js';
+import { ServicePool, type PoolStatus } from '../service-pool.js';
+import type { RondevuOffers } from '../offers.js';
+import { DurableChannel } from './channel.js';
+import type {
+  DurableServiceConfig,
+  DurableServiceEvents,
+  ServiceInfo
+} from './types.js';
+
+/**
+ * Connection handler callback
+ */
+export type ConnectionHandler = (
+  channel: DurableChannel,
+  connectionId: string
+) => void | Promise<void>;
+
+/**
+ * Default configuration for durable services
+ */
+const DEFAULT_CONFIG = {
+  isPublic: false,
+  ttlRefreshMargin: 0.2,
+  poolSize: 1,
+  pollingInterval: 2000,
+  maxReconnectAttempts: 10,
+  reconnectBackoffBase: 1000,
+  reconnectBackoffMax: 30000,
+  reconnectJitter: 0.2,
+  connectionTimeout: 30000,
+  maxQueueSize: 1000,
+  maxMessageAge: 60000,
+  rtcConfig: {
+    iceServers: [
+      { urls: 'stun:stun.l.google.com:19302' },
+      { urls: 'stun:stun1.l.google.com:19302' }
+    ]
+  }
+};
+
+/**
+ * Durable service that automatically refreshes TTL and handles reconnections
+ *
+ * The DurableService manages service publishing and provides:
+ * - Automatic TTL refresh before expiration
+ * - Durable connections for incoming peers
+ * - Connection pooling for multiple simultaneous connections
+ * - High-level connection lifecycle events
+ *
+ * @example
+ * ```typescript
+ * const service = new DurableService(
+ *   offersApi,
+ *   (channel, connectionId) => {
+ *     channel.on('message', (data) => {
+ *       console.log(`Message from ${connectionId}:`, data);
+ *       channel.send(`Echo: ${data}`);
+ *     });
+ *   },
+ *   {
+ *     username: 'alice',
+ *     privateKey: keypair.privateKey,
+ *     serviceFqn: 'chat@1.0.0',
+ *     poolSize: 10
+ *   }
+ * );
+ *
+ * service.on('published', (serviceId, uuid) => {
+ *   console.log(`Service published: ${uuid}`);
+ * });
+ *
+ * service.on('connection', (connectionId) => {
+ *   console.log(`New connection: ${connectionId}`);
+ * });
+ *
+ * await service.start();
+ * ```
+ */
+export class DurableService extends EventEmitter<DurableServiceEvents> {
+  readonly config: Required<DurableServiceConfig>;
+
+  private serviceId?: string;
+  private uuid?: string;
+  private expiresAt?: number;
+  private ttlRefreshTimer?: ReturnType<typeof setTimeout>;
+  private servicePool?: ServicePool;
+  private activeChannels: Map<string, DurableChannel> = new Map();
+
+  constructor(
+    private offersApi: RondevuOffers,
+    private baseUrl: string,
+    private credentials: { peerId: string; secret: string },
+    private handler: ConnectionHandler,
+    config: DurableServiceConfig
+  ) {
+    super();
+    this.config = { ...DEFAULT_CONFIG, ...config } as Required<DurableServiceConfig>;
+  }
+
+  /**
+   * Start the service
+   *
+   * Publishes the service and begins accepting connections.
+   *
+   * @returns Service information
+   */
+  async start(): Promise<ServiceInfo> {
+    if (this.servicePool) {
+      throw new Error('Service already started');
+    }
+
+    // Create and start service pool
+    this.servicePool = new ServicePool(
+      this.baseUrl,
+      this.credentials,
+      {
+        username: this.config.username,
+        privateKey: this.config.privateKey,
+        serviceFqn: this.config.serviceFqn,
+        rtcConfig: this.config.rtcConfig,
+        isPublic: this.config.isPublic,
+        metadata: this.config.metadata,
+        ttl: this.config.ttl,
+        poolSize: this.config.poolSize,
+        pollingInterval: this.config.pollingInterval,
+        handler: (channel, peer, connectionId) => {
+          this.handleNewConnection(channel, connectionId);
+        },
+        onPoolStatus: (status) => {
+          // Could emit pool status event if needed
+        },
+        onError: (error, context) => {
+          this.emit('error', error, context);
+        }
+      }
+    );
+
+    const handle = await this.servicePool.start();
+
+    // Store service info
+    this.serviceId = handle.serviceId;
+    this.uuid = handle.uuid;
+    this.expiresAt = Date.now() + (this.config.ttl || 300000); // Default 5 minutes
+
+    this.emit('published', this.serviceId, this.uuid);
+
+    // Schedule TTL refresh
+    this.scheduleRefresh();
+
+    return {
+      serviceId: this.serviceId,
+      uuid: this.uuid,
+      expiresAt: this.expiresAt
+    };
+  }
+
+  /**
+   * Stop the service
+   *
+   * Unpublishes the service and closes all active connections.
+   */
+  async stop(): Promise<void> {
+    // Cancel TTL refresh
+    if (this.ttlRefreshTimer) {
+      clearTimeout(this.ttlRefreshTimer);
+      this.ttlRefreshTimer = undefined;
+    }
+
+    // Close all active channels
+    for (const channel of this.activeChannels.values()) {
+      channel.close();
+    }
+    this.activeChannels.clear();
+
+    // Stop service pool
+    if (this.servicePool) {
+      await this.servicePool.stop();
+      this.servicePool = undefined;
+    }
+
+    this.emit('closed');
+  }
+
+  /**
+   * Get list of active connection IDs
+   */
+  getActiveConnections(): string[] {
+    return Array.from(this.activeChannels.keys());
+  }
+
+  /**
+   * Get service information
+   */
+  getServiceInfo(): ServiceInfo | null {
+    if (!this.serviceId || !this.uuid || !this.expiresAt) {
+      return null;
+    }
+
+    return {
+      serviceId: this.serviceId,
+      uuid: this.uuid,
+      expiresAt: this.expiresAt
+    };
+  }
+
+  /**
+   * Schedule TTL refresh
+   */
+  private scheduleRefresh(): void {
+    if (!this.expiresAt || !this.config.ttl) {
+      return;
+    }
+
+    // Cancel existing timer
+    if (this.ttlRefreshTimer) {
+      clearTimeout(this.ttlRefreshTimer);
+    }
+
+    // Calculate refresh time (default: refresh at 80% of TTL)
+    const timeUntilExpiry = this.expiresAt - Date.now();
+    const refreshMargin = timeUntilExpiry * this.config.ttlRefreshMargin;
+    const refreshTime = Math.max(0, timeUntilExpiry - refreshMargin);
+
+    // Schedule refresh
+    this.ttlRefreshTimer = setTimeout(() => {
+      this.refreshServiceTTL().catch(error => {
+        this.emit('error', error, 'ttl-refresh');
+        // Retry after short delay
+        setTimeout(() => this.scheduleRefresh(), 5000);
+      });
+    }, refreshTime);
+  }
+
+  /**
+   * Refresh service TTL
+   */
+  private async refreshServiceTTL(): Promise<void> {
+    if (!this.serviceId || !this.uuid) {
+      return;
+    }
+
+    // Delete old service
+    await this.servicePool?.stop();
+
+    // Recreate service pool (this republishes the service)
+    this.servicePool = new ServicePool(
+      this.baseUrl,
+      this.credentials,
+      {
+        username: this.config.username,
+        privateKey: this.config.privateKey,
+        serviceFqn: this.config.serviceFqn,
+        rtcConfig: this.config.rtcConfig,
+        isPublic: this.config.isPublic,
+        metadata: this.config.metadata,
+        ttl: this.config.ttl,
+        poolSize: this.config.poolSize,
+        pollingInterval: this.config.pollingInterval,
+        handler: (channel, peer, connectionId) => {
+          this.handleNewConnection(channel, connectionId);
+        },
+        onPoolStatus: (status) => {
+          // Could emit pool status event if needed
+        },
+        onError: (error, context) => {
+          this.emit('error', error, context);
+        }
+      }
+    );
+
+    const handle = await this.servicePool.start();
+
+    // Update service info
+    this.serviceId = handle.serviceId;
+    this.uuid = handle.uuid;
+    this.expiresAt = Date.now() + (this.config.ttl || 300000);
+
+    this.emit('ttl-refreshed', this.expiresAt);
+
+    // Schedule next refresh
+    this.scheduleRefresh();
+  }
+
+  /**
+   * Handle new incoming connection
+   */
+  private handleNewConnection(channel: RTCDataChannel, connectionId: string): void {
+    // Create durable channel
+    const durableChannel = new DurableChannel(channel.label, {
+      maxQueueSize: this.config.maxQueueSize,
+      maxMessageAge: this.config.maxMessageAge
+    });
+
+    // Attach to underlying channel
+    durableChannel.attachToChannel(channel);
+
+    // Track channel
+    this.activeChannels.set(connectionId, durableChannel);
+
+    // Setup cleanup on close
+    durableChannel.on('close', () => {
+      this.activeChannels.delete(connectionId);
+      this.emit('disconnection', connectionId);
+    });
+
+    // Emit connection event
+    this.emit('connection', connectionId);
+
+    // Invoke user handler
+    try {
+      const result = this.handler(durableChannel, connectionId);
+      if (result && typeof result.then === 'function') {
+        result.catch(error => {
+          this.emit('error', error, 'handler');
+        });
+      }
+    } catch (error) {
+      this.emit('error', error as Error, 'handler');
+    }
+  }
+}

src/durable/types.ts

@@ -0,0 +1,184 @@
+/**
+ * Type definitions for durable WebRTC connections
+ *
+ * This module defines all interfaces, enums, and types used by the durable
+ * connection system for automatic reconnection and message queuing.
+ */
+
+/**
+ * Connection state enum
+ */
+export enum DurableConnectionState {
+  CONNECTING = 'connecting',
+  CONNECTED = 'connected',
+  RECONNECTING = 'reconnecting',
+  DISCONNECTED = 'disconnected',
+  FAILED = 'failed',
+  CLOSED = 'closed'
+}
+
+/**
+ * Channel state enum
+ */
+export enum DurableChannelState {
+  CONNECTING = 'connecting',
+  OPEN = 'open',
+  CLOSING = 'closing',
+  CLOSED = 'closed'
+}
+
+/**
+ * Configuration for durable connections
+ */
+export interface DurableConnectionConfig {
+  /** Maximum number of reconnection attempts (default: 10) */
+  maxReconnectAttempts?: number;
+
+  /** Base delay for exponential backoff in milliseconds (default: 1000) */
+  reconnectBackoffBase?: number;
+
+  /** Maximum delay between reconnection attempts in milliseconds (default: 30000) */
+  reconnectBackoffMax?: number;
+
+  /** Jitter factor for randomizing reconnection delays (default: 0.2 = ±20%) */
+  reconnectJitter?: number;
+
+  /** Timeout for initial connection attempt in milliseconds (default: 30000) */
+  connectionTimeout?: number;
+
+  /** Maximum number of messages to queue during disconnection (default: 1000) */
+  maxQueueSize?: number;
+
+  /** Maximum age of queued messages in milliseconds (default: 60000) */
+  maxMessageAge?: number;
+
+  /** WebRTC configuration */
+  rtcConfig?: RTCConfiguration;
+}
+
+/**
+ * Configuration for durable channels
+ */
+export interface DurableChannelConfig {
+  /** Maximum number of messages to queue (default: 1000) */
+  maxQueueSize?: number;
+
+  /** Maximum age of queued messages in milliseconds (default: 60000) */
+  maxMessageAge?: number;
+
+  /** Whether messages should be delivered in order (default: true) */
+  ordered?: boolean;
+
+  /** Maximum retransmits for unordered channels (default: undefined) */
+  maxRetransmits?: number;
+}
+
+/**
+ * Configuration for durable services
+ */
+export interface DurableServiceConfig extends DurableConnectionConfig {
+  /** Username that owns the service */
+  username: string;
+
+  /** Private key for signing service operations */
+  privateKey: string;
+
+  /** Fully qualified service name (e.g., com.example.chat@1.0.0) */
+  serviceFqn: string;
+
+  /** Whether the service is publicly discoverable (default: false) */
+  isPublic?: boolean;
+
+  /** Optional metadata for the service */
+  metadata?: Record<string, any>;
+
+  /** Time-to-live for service in milliseconds (default: server default) */
+  ttl?: number;
+
+  /** Margin before TTL expiry to trigger refresh (default: 0.2 = refresh at 80%) */
+  ttlRefreshMargin?: number;
+
+  /** Number of simultaneous open offers to maintain (default: 1) */
+  poolSize?: number;
+
+  /** Polling interval for checking answers in milliseconds (default: 2000) */
+  pollingInterval?: number;
+}
+
+/**
+ * Queued message structure
+ */
+export interface QueuedMessage {
+  /** Message data */
+  data: string | Blob | ArrayBuffer | ArrayBufferView;
+
+  /** Timestamp when message was enqueued */
+  enqueuedAt: number;
+
+  /** Unique message ID */
+  id: string;
+}
+
+/**
+ * Event type map for DurableConnection
+ */
+export interface DurableConnectionEvents extends Record<string, (...args: any[]) => void> {
+  'state': (state: DurableConnectionState, previousState: DurableConnectionState) => void;
+  'connected': () => void;
+  'reconnecting': (attempt: number, maxAttempts: number, nextRetryIn: number) => void;
+  'disconnected': () => void;
+  'failed': (error: Error, permanent: boolean) => void;
+  'closed': () => void;
+}
+
+/**
+ * Event type map for DurableChannel
+ */
+export interface DurableChannelEvents extends Record<string, (...args: any[]) => void> {
+  'open': () => void;
+  'message': (data: any) => void;
+  'error': (error: Error) => void;
+  'close': () => void;
+  'bufferedAmountLow': () => void;
+  'queueOverflow': (droppedCount: number) => void;
+}
+
+/**
+ * Event type map for DurableService
+ */
+export interface DurableServiceEvents extends Record<string, (...args: any[]) => void> {
+  'published': (serviceId: string, uuid: string) => void;
+  'connection': (connectionId: string) => void;
+  'disconnection': (connectionId: string) => void;
+  'ttl-refreshed': (expiresAt: number) => void;
+  'error': (error: Error, context: string) => void;
+  'closed': () => void;
+}
+
+/**
+ * Information about a durable connection
+ */
+export interface ConnectionInfo {
+  /** Username (for username-based connections) */
+  username?: string;
+
+  /** Service FQN (for service-based connections) */
+  serviceFqn?: string;
+
+  /** UUID (for UUID-based connections) */
+  uuid?: string;
+}
+
+/**
+ * Service information returned when service is published
+ */
+export interface ServiceInfo {
+  /** Service ID */
+  serviceId: string;
+
+  /** Service UUID for discovery */
+  uuid: string;
+
+  /** Expiration timestamp */
+  expiresAt: number;
+}

src/index.ts

@@ -1,6 +1,6 @@
 /**
  * @xtr-dev/rondevu-client
- * WebRTC peer signaling and discovery client with topic-based discovery
+ * WebRTC peer signaling and discovery client with durable connections
  */
 
 // Export main client class
@@ -11,22 +11,26 @@ export type { RondevuOptions } from './rondevu.js';
 export { RondevuAuth } from './auth.js';
 export type { Credentials, FetchFunction } from './auth.js';
 
-// Export offers API
+// Export username API
-export { RondevuOffers } from './offers.js';
+export { RondevuUsername } from './usernames.js';
-export type {
+export type { UsernameClaimResult, UsernameCheckResult } from './usernames.js';
-  CreateOfferRequest,
-  Offer,
-  IceCandidate,
-  TopicInfo
-} from './offers.js';
 
-// Export bloom filter
+// Export durable connection APIs
-export { BloomFilter } from './bloom.js';
+export { DurableConnection } from './durable/connection.js';
+export { DurableChannel } from './durable/channel.js';
+export { DurableService } from './durable/service.js';
 
-// Export peer manager
+// Export durable connection types
-export { default as RondevuPeer } from './peer/index.js';
 export type {
-  PeerOptions,
+  DurableConnectionState,
-  PeerEvents,
+  DurableChannelState,
-  PeerTimeouts
+  DurableConnectionConfig,
-} from './peer/index.js';
+  DurableChannelConfig,
+  DurableServiceConfig,
+  QueuedMessage,
+  DurableConnectionEvents,
+  DurableChannelEvents,
+  DurableServiceEvents,
+  ConnectionInfo,
+  ServiceInfo
+} from './durable/types.js';

src/offer-pool.ts

@@ -0,0 +1,205 @@
+import { RondevuOffers, Offer } from './offers.js';
+
+/**
+ * Represents an offer that has been answered
+ */
+export interface AnsweredOffer {
+  offerId: string;
+  answererId: string;
+  sdp: string; // Answer SDP
+  peerConnection: RTCPeerConnection; // Original peer connection
+  dataChannel?: RTCDataChannel; // Data channel created with offer
+  answeredAt: number;
+}
+
+/**
+ * Configuration options for the offer pool
+ */
+export interface OfferPoolOptions {
+  /** Number of simultaneous open offers to maintain */
+  poolSize: number;
+
+  /** Polling interval in milliseconds (default: 2000ms) */
+  pollingInterval?: number;
+
+  /** Callback invoked when an offer is answered */
+  onAnswered: (answer: AnsweredOffer) => Promise<void>;
+
+  /** Callback to create new offers when refilling the pool */
+  onRefill: (count: number) => Promise<{ offers: Offer[], peerConnections: RTCPeerConnection[], dataChannels: RTCDataChannel[] }>;
+
+  /** Error handler for pool operations */
+  onError: (error: Error, context: string) => void;
+}
+
+/**
+ * Manages a pool of offers with automatic polling and refill
+ *
+ * The OfferPool maintains a configurable number of simultaneous offers,
+ * polls for answers periodically, and automatically refills the pool
+ * when offers are consumed.
+ */
+export class OfferPool {
+  private offers: Map<string, Offer> = new Map();
+  private peerConnections: Map<string, RTCPeerConnection> = new Map();
+  private dataChannels: Map<string, RTCDataChannel> = new Map();
+  private polling: boolean = false;
+  private pollingTimer?: ReturnType<typeof setInterval>;
+  private lastPollTime: number = 0;
+  private readonly pollingInterval: number;
+
+  constructor(
+    private offersApi: RondevuOffers,
+    private options: OfferPoolOptions
+  ) {
+    this.pollingInterval = options.pollingInterval || 2000;
+  }
+
+  /**
+   * Add offers to the pool with their peer connections and data channels
+   */
+  async addOffers(offers: Offer[], peerConnections?: RTCPeerConnection[], dataChannels?: RTCDataChannel[]): Promise<void> {
+    for (let i = 0; i < offers.length; i++) {
+      const offer = offers[i];
+      this.offers.set(offer.id, offer);
+      if (peerConnections && peerConnections[i]) {
+        this.peerConnections.set(offer.id, peerConnections[i]);
+      }
+      if (dataChannels && dataChannels[i]) {
+        this.dataChannels.set(offer.id, dataChannels[i]);
+      }
+    }
+  }
+
+  /**
+   * Start polling for answers
+   */
+  async start(): Promise<void> {
+    if (this.polling) {
+      return;
+    }
+
+    this.polling = true;
+
+    // Do an immediate poll
+    await this.poll().catch((error) => {
+      this.options.onError(error, 'initial-poll');
+    });
+
+    // Start polling interval
+    this.pollingTimer = setInterval(async () => {
+      if (this.polling) {
+        await this.poll().catch((error) => {
+          this.options.onError(error, 'poll');
+        });
+      }
+    }, this.pollingInterval);
+  }
+
+  /**
+   * Stop polling for answers
+   */
+  async stop(): Promise<void> {
+    this.polling = false;
+
+    if (this.pollingTimer) {
+      clearInterval(this.pollingTimer);
+      this.pollingTimer = undefined;
+    }
+  }
+
+  /**
+   * Poll for answers and refill the pool if needed
+   */
+  private async poll(): Promise<void> {
+    try {
+      // Get all answers from server
+      const answers = await this.offersApi.getAnswers();
+
+      // Filter for our pool's offers
+      const myAnswers = answers.filter(a => this.offers.has(a.offerId));
+
+      // Process each answer
+      for (const answer of myAnswers) {
+        // Get the original offer, peer connection, and data channel
+        const offer = this.offers.get(answer.offerId);
+        const pc = this.peerConnections.get(answer.offerId);
+        const channel = this.dataChannels.get(answer.offerId);
+
+        if (!offer || !pc) {
+          continue; // Offer or peer connection already consumed, skip
+        }
+
+        // Remove from pool BEFORE processing to prevent duplicate processing
+        this.offers.delete(answer.offerId);
+        this.peerConnections.delete(answer.offerId);
+        this.dataChannels.delete(answer.offerId);
+
+        // Notify ServicePool with answer, original peer connection, and data channel
+        await this.options.onAnswered({
+          offerId: answer.offerId,
+          answererId: answer.answererId,
+          sdp: answer.sdp,
+          peerConnection: pc,
+          dataChannel: channel,
+          answeredAt: answer.answeredAt
+        });
+      }
+
+      // Immediate refill if below pool size
+      if (this.offers.size < this.options.poolSize) {
+        const needed = this.options.poolSize - this.offers.size;
+
+        try {
+          const result = await this.options.onRefill(needed);
+          await this.addOffers(result.offers, result.peerConnections, result.dataChannels);
+        } catch (refillError) {
+          this.options.onError(
+            refillError as Error,
+            'refill'
+          );
+        }
+      }
+
+      this.lastPollTime = Date.now();
+    } catch (error) {
+      // Don't crash the pool on errors - let error handler deal with it
+      this.options.onError(error as Error, 'poll');
+    }
+  }
+
+  /**
+   * Get the current number of active offers in the pool
+   */
+  getActiveOfferCount(): number {
+    return this.offers.size;
+  }
+
+  /**
+   * Get all active offer IDs
+   */
+  getActiveOfferIds(): string[] {
+    return Array.from(this.offers.keys());
+  }
+
+  /**
+   * Get all active peer connections
+   */
+  getActivePeerConnections(): RTCPeerConnection[] {
+    return Array.from(this.peerConnections.values());
+  }
+
+  /**
+   * Get the last poll timestamp
+   */
+  getLastPollTime(): number {
+    return this.lastPollTime;
+  }
+
+  /**
+   * Check if the pool is currently polling
+   */
+  isPolling(): boolean {
+    return this.polling;
+  }
+}

src/offers.ts

@@ -8,6 +8,8 @@ export interface CreateOfferRequest {
   sdp: string;
   topics: string[];
   ttl?: number;
+  secret?: string;
+  info?: string;
 }
 
 export interface Offer {
@@ -18,6 +20,9 @@ export interface Offer {
   createdAt?: number;
   expiresAt: number;
   lastSeen: number;
+  secret?: string;
+  hasSecret?: boolean;
+  info?: string;
   answererPeerId?: string;
   answerSdp?: string;
   answeredAt?: number;
@@ -143,11 +148,13 @@ export class RondevuOffers {
   async getTopics(options?: {
     limit?: number;
     offset?: number;
+    startsWith?: string;
   }): Promise<{
     topics: TopicInfo[];
     total: number;
     limit: number;
     offset: number;
+    startsWith?: string;
   }> {
     const params = new URLSearchParams();
 
@@ -159,6 +166,10 @@ export class RondevuOffers {
       params.set('offset', options.offset.toString());
     }
 
+    if (options?.startsWith) {
+      params.set('startsWith', options.startsWith);
+    }
+
     const url = `${this.baseUrl}/topics${
       params.toString() ? '?' + params.toString() : ''
     }`;
@@ -195,23 +206,6 @@ export class RondevuOffers {
     return data.offers;
   }
 
-  /**
-   * Update offer heartbeat
-   */
-  async heartbeat(offerId: string): Promise<void> {
-    const response = await this.fetchFn(`${this.baseUrl}/offers/${encodeURIComponent(offerId)}/heartbeat`, {
-      method: 'PUT',
-      headers: {
-        Authorization: RondevuAuth.createAuthHeader(this.credentials),
-      },
-    });
-
-    if (!response.ok) {
-      const error = await response.json().catch(() => ({ error: 'Unknown error' }));
-      throw new Error(`Failed to update heartbeat: ${error.error || response.statusText}`);
-    }
-  }
-
   /**
    * Delete an offer
    */
@@ -232,14 +226,14 @@ export class RondevuOffers {
   /**
    * Answer an offer
    */
-  async answer(offerId: string, sdp: string): Promise<void> {
+  async answer(offerId: string, sdp: string, secret?: string): Promise<void> {
     const response = await this.fetchFn(`${this.baseUrl}/offers/${encodeURIComponent(offerId)}/answer`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
         Authorization: RondevuAuth.createAuthHeader(this.credentials),
       },
-      body: JSON.stringify({ sdp }),
+      body: JSON.stringify({ sdp, secret }),
     });
 
     if (!response.ok) {

src/peer/answering-state.ts

@@ -25,25 +25,18 @@ export class AnsweringState extends PeerState {
 
       // Create answer
       const answer = await this.peer.pc.createAnswer();
+
+      // Send answer to server BEFORE setLocalDescription
+      // This registers us as the answerer so ICE candidates will be accepted
+      await this.peer.offersApi.answer(offerId, answer.sdp!, options.secret);
+
+      // Enable trickle ICE - set up handler before ICE gathering starts
+      this.setupIceCandidateHandler();
+
+      // Set local description - ICE gathering starts here
+      // Server already knows we're the answerer, so candidates will be accepted
       await this.peer.pc.setLocalDescription(answer);
 
-      // Send answer to server immediately (don't wait for ICE)
-      await this.peer.offersApi.answer(offerId, answer.sdp!);
-
-      // Enable trickle ICE - send candidates as they arrive
-      this.peer.pc.onicecandidate = async (event: RTCPeerConnectionIceEvent) => {
-        if (event.candidate && offerId) {
-          const candidateData = event.candidate.toJSON();
-          if (candidateData.candidate && candidateData.candidate !== '') {
-            try {
-              await this.peer.offersApi.addIceCandidates(offerId, [candidateData]);
-            } catch (err) {
-              console.error('Error sending ICE candidate:', err);
-            }
-          }
-        }
-      };
-
       // Transition to exchanging ICE
       const { ExchangingIceState } = await import('./exchanging-ice-state.js');
       this.peer.setState(new ExchangingIceState(this.peer, offerId, options));

src/peer/creating-offer-state.ts

@@ -24,33 +24,24 @@ export class CreatingOfferState extends PeerState {
         this.peer.emitEvent('datachannel', channel);
       }
 
+      // Enable trickle ICE - set up handler before ICE gathering starts
+      // Handler will check this.peer.offerId before sending
+      this.setupIceCandidateHandler();
+
       // Create WebRTC offer
       const offer = await this.peer.pc.createOffer();
-      await this.peer.pc.setLocalDescription(offer);
+      await this.peer.pc.setLocalDescription(offer); // ICE gathering starts here
 
       // Send offer to server immediately (don't wait for ICE)
       const offers = await this.peer.offersApi.create([{
         sdp: offer.sdp!,
         topics: options.topics,
-        ttl: options.ttl || 300000
+        ttl: options.ttl || 300000,
+        secret: options.secret
       }]);
 
       const offerId = offers[0].id;
-      this.peer.offerId = offerId;
+      this.peer.offerId = offerId; // Now handler can send candidates
-
-      // Enable trickle ICE - send candidates as they arrive
-      this.peer.pc.onicecandidate = async (event: RTCPeerConnectionIceEvent) => {
-        if (event.candidate && offerId) {
-          const candidateData = event.candidate.toJSON();
-          if (candidateData.candidate && candidateData.candidate !== '') {
-            try {
-              await this.peer.offersApi.addIceCandidates(offerId, [candidateData]);
-            } catch (err) {
-              console.error('Error sending ICE candidate:', err);
-            }
-          }
-        }
-      };
 
       // Transition to waiting for answer
       const { WaitingForAnswerState } = await import('./waiting-for-answer-state.js');

src/peer/exchanging-ice-state.ts

@@ -40,13 +40,22 @@ export class ExchangingIceState extends PeerState {
           this.lastIceTimestamp
         );
 
+        if (candidates.length > 0) {
+          console.log(`📥 Received ${candidates.length} remote ICE candidate(s)`);
+        }
+
         for (const cand of candidates) {
           if (cand.candidate && cand.candidate.candidate && cand.candidate.candidate !== '') {
+            const type = cand.candidate.candidate.includes('typ host') ? 'host' :
+                         cand.candidate.candidate.includes('typ srflx') ? 'srflx' :
+                         cand.candidate.candidate.includes('typ relay') ? 'relay' : 'unknown';
+            console.log(`🧊 Adding remote ${type} ICE candidate:`, cand.candidate.candidate);
             try {
-              await this.peer.pc.addIceCandidate(new RTCIceCandidate(cand.candidate));
+              await this.peer.pc.addIceCandidate(new this.peer.RTCIceCandidate(cand.candidate));
+              console.log(`✅ Added remote ${type} ICE candidate`);
               this.lastIceTimestamp = cand.createdAt;
             } catch (err) {
-              console.warn('Failed to add ICE candidate:', err);
+              console.warn(`⚠️ Failed to add remote ${type} ICE candidate:`, err);
               this.lastIceTimestamp = cand.createdAt;
             }
           } else {
@@ -54,7 +63,7 @@ export class ExchangingIceState extends PeerState {
           }
         }
       } catch (err) {
-        console.error('Error polling for ICE candidates:', err);
+        console.error('❌ Error polling for ICE candidates:', err);
         if (err instanceof Error && err.message.includes('not found')) {
           this.cleanup();
           const { FailedState } = await import('./failed-state.js');

src/peer/index.ts

@@ -24,8 +24,19 @@ export default class RondevuPeer extends EventEmitter<PeerEvents> {
   offerId?: string;
   role?: 'offerer' | 'answerer';
 
+  // WebRTC polyfills for Node.js compatibility
+  RTCPeerConnection: typeof RTCPeerConnection;
+  RTCSessionDescription: typeof RTCSessionDescription;
+  RTCIceCandidate: typeof RTCIceCandidate;
+
   private _state: PeerState;
 
+  // Event handler references for cleanup
+  private connectionStateChangeHandler?: () => void;
+  private dataChannelHandler?: (event: RTCDataChannelEvent) => void;
+  private trackHandler?: (event: RTCTrackEvent) => void;
+  private iceCandidateErrorHandler?: (event: Event) => void;
+
   /**
    * Current connection state name
    */
@@ -54,11 +65,36 @@ export default class RondevuPeer extends EventEmitter<PeerEvents> {
         { urls: 'stun:stun.l.google.com:19302' },
         { urls: 'stun:stun1.l.google.com:19302' }
       ]
-    }
+    },
+    existingPeerConnection?: RTCPeerConnection,
+    rtcPeerConnection?: typeof RTCPeerConnection,
+    rtcSessionDescription?: typeof RTCSessionDescription,
+    rtcIceCandidate?: typeof RTCIceCandidate
   ) {
     super();
     this.offersApi = offersApi;
-    this.pc = new RTCPeerConnection(rtcConfig);
+
+    // Use provided polyfills or fall back to globals
+    this.RTCPeerConnection = rtcPeerConnection || (typeof globalThis.RTCPeerConnection !== 'undefined'
+      ? globalThis.RTCPeerConnection
+      : (() => {
+          throw new Error('RTCPeerConnection is not available. Please provide it in the Rondevu constructor options for Node.js environments.');
+        }) as any);
+
+    this.RTCSessionDescription = rtcSessionDescription || (typeof globalThis.RTCSessionDescription !== 'undefined'
+      ? globalThis.RTCSessionDescription
+      : (() => {
+          throw new Error('RTCSessionDescription is not available. Please provide it in the Rondevu constructor options for Node.js environments.');
+        }) as any);
+
+    this.RTCIceCandidate = rtcIceCandidate || (typeof globalThis.RTCIceCandidate !== 'undefined'
+      ? globalThis.RTCIceCandidate
+      : (() => {
+          throw new Error('RTCIceCandidate is not available. Please provide it in the Rondevu constructor options for Node.js environments.');
+        }) as any);
+
+    // Use existing peer connection if provided, otherwise create new one
+    this.pc = existingPeerConnection || new this.RTCPeerConnection(rtcConfig);
     this._state = new IdleState(this);
 
     this.setupPeerConnection();
@@ -68,36 +104,63 @@ export default class RondevuPeer extends EventEmitter<PeerEvents> {
    * Set up peer connection event handlers
    */
   private setupPeerConnection(): void {
-    this.pc.onconnectionstatechange = () => {
+    this.connectionStateChangeHandler = () => {
+      console.log(`🔌 Connection state changed: ${this.pc.connectionState}`);
       switch (this.pc.connectionState) {
         case 'connected':
+          console.log('✅ WebRTC connection established');
           this.setState(new ConnectedState(this));
           this.emitEvent('connected');
           break;
         case 'disconnected':
+          console.log('⚠️ WebRTC connection disconnected');
           this.emitEvent('disconnected');
           break;
         case 'failed':
+          console.log('❌ WebRTC connection failed');
           this.setState(new FailedState(this, new Error('Connection failed')));
           break;
         case 'closed':
+          console.log('🔒 WebRTC connection closed');
           this.setState(new ClosedState(this));
           this.emitEvent('disconnected');
           break;
       }
     };
+    this.pc.addEventListener('connectionstatechange', this.connectionStateChangeHandler);
 
-    this.pc.ondatachannel = (event) => {
+    // Add ICE connection state logging
+    const iceConnectionStateHandler = () => {
+      console.log(`🧊 ICE connection state: ${this.pc.iceConnectionState}`);
+    };
+    this.pc.addEventListener('iceconnectionstatechange', iceConnectionStateHandler);
+
+    // Add ICE gathering state logging
+    const iceGatheringStateHandler = () => {
+      console.log(`🔍 ICE gathering state: ${this.pc.iceGatheringState}`);
+    };
+    this.pc.addEventListener('icegatheringstatechange', iceGatheringStateHandler);
+
+    this.dataChannelHandler = (event: RTCDataChannelEvent) => {
       this.emitEvent('datachannel', event.channel);
     };
+    this.pc.addEventListener('datachannel', this.dataChannelHandler);
 
-    this.pc.ontrack = (event) => {
+    this.trackHandler = (event: RTCTrackEvent) => {
       this.emitEvent('track', event);
     };
+    this.pc.addEventListener('track', this.trackHandler);
 
-    this.pc.onicecandidateerror = (event) => {
+    this.iceCandidateErrorHandler = (event: Event) => {
-      console.error('ICE candidate error:', event);
+      const iceError = event as RTCPeerConnectionIceErrorEvent;
+      console.error(`❌ ICE candidate error: ${iceError.errorText || 'Unknown error'}`, {
+        errorCode: iceError.errorCode,
+        url: iceError.url,
+        address: iceError.address,
+        port: iceError.port
+      });
     };
+    this.pc.addEventListener('icecandidateerror', this.iceCandidateErrorHandler);
   }
 
   /**
@@ -141,10 +204,33 @@ export default class RondevuPeer extends EventEmitter<PeerEvents> {
     return this.pc.addTrack(track, ...streams);
   }
 
+  /**
+   * Create a data channel for sending and receiving arbitrary data
+   * This should typically be called by the offerer before creating the offer
+   * The answerer will receive the channel via the 'datachannel' event
+   */
+  createDataChannel(label: string, options?: RTCDataChannelInit): RTCDataChannel {
+    return this.pc.createDataChannel(label, options);
+  }
+
   /**
    * Close the connection and clean up
    */
   async close(): Promise<void> {
+    // Remove RTCPeerConnection event listeners
+    if (this.connectionStateChangeHandler) {
+      this.pc.removeEventListener('connectionstatechange', this.connectionStateChangeHandler);
+    }
+    if (this.dataChannelHandler) {
+      this.pc.removeEventListener('datachannel', this.dataChannelHandler);
+    }
+    if (this.trackHandler) {
+      this.pc.removeEventListener('track', this.trackHandler);
+    }
+    if (this.iceCandidateErrorHandler) {
+      this.pc.removeEventListener('icecandidateerror', this.iceCandidateErrorHandler);
+    }
+
     await this._state.close();
     this.removeAllListeners();
   }

src/peer/state.ts

@@ -6,6 +6,8 @@ import type RondevuPeer from './index.js';
  * Implements the State pattern for managing WebRTC connection lifecycle
  */
 export abstract class PeerState {
+  protected iceCandidateHandler?: (event: RTCPeerConnectionIceEvent) => void;
+
   constructor(protected peer: RondevuPeer) {}
 
   abstract get name(): string;
@@ -25,12 +27,42 @@ export abstract class PeerState {
   async handleIceCandidate(candidate: any): Promise<void> {
     // ICE candidates can arrive in multiple states, so default is to add them
     if (this.peer.pc.remoteDescription) {
-      await this.peer.pc.addIceCandidate(new RTCIceCandidate(candidate));
+      await this.peer.pc.addIceCandidate(new this.peer.RTCIceCandidate(candidate));
     }
   }
 
+  /**
+   * Setup trickle ICE candidate handler
+   * Sends local ICE candidates to server as they are discovered
+   */
+  protected setupIceCandidateHandler(): void {
+    this.iceCandidateHandler = async (event: RTCPeerConnectionIceEvent) => {
+      if (event.candidate && this.peer.offerId) {
+        const candidateData = event.candidate.toJSON();
+        if (candidateData.candidate && candidateData.candidate !== '') {
+          const type = candidateData.candidate.includes('typ host') ? 'host' :
+                       candidateData.candidate.includes('typ srflx') ? 'srflx' :
+                       candidateData.candidate.includes('typ relay') ? 'relay' : 'unknown';
+          console.log(`🧊 Generated ${type} ICE candidate:`, candidateData.candidate);
+          try {
+            await this.peer.offersApi.addIceCandidates(this.peer.offerId, [candidateData]);
+            console.log(`✅ Sent ${type} ICE candidate to server`);
+          } catch (err) {
+            console.error(`❌ Error sending ${type} ICE candidate:`, err);
+          }
+        }
+      } else if (!event.candidate) {
+        console.log('🧊 ICE gathering complete (null candidate)');
+      }
+    };
+    this.peer.pc.addEventListener('icecandidate', this.iceCandidateHandler);
+  }
+
   cleanup(): void {
-    // Override in states that need cleanup
+    // Clean up ICE candidate handler if it exists
+    if (this.iceCandidateHandler) {
+      this.peer.pc.removeEventListener('icecandidate', this.iceCandidateHandler);
+    }
   }
 
   async close(): Promise<void> {

src/peer/types.ts

@@ -22,6 +22,8 @@ export interface PeerOptions {
   topics: string[];
   /** How long the offer should live (milliseconds) */
   ttl?: number;
+  /** Optional secret to protect the offer (max 128 characters) */
+  secret?: string;
   /** Whether to create a data channel automatically (for offerer) */
   createDataChannel?: boolean;
   /** Label for the automatically created data channel */

src/rondevu.ts

@@ -1,6 +1,15 @@
 import { RondevuAuth, Credentials, FetchFunction } from './auth.js';
 import { RondevuOffers } from './offers.js';
+import { RondevuUsername } from './usernames.js';
 import RondevuPeer from './peer/index.js';
+import { DurableService } from './durable/service.js';
+import { DurableConnection } from './durable/connection.js';
+import { DurableChannel } from './durable/channel.js';
+import type {
+  DurableServiceConfig,
+  DurableConnectionConfig,
+  ConnectionInfo
+} from './durable/types.js';
 
 export interface RondevuOptions {
   /**
@@ -25,20 +34,65 @@ export interface RondevuOptions {
    * ```
    */
   fetch?: FetchFunction;
+
+  /**
+   * Custom RTCPeerConnection implementation for Node.js environments
+   * Required when using in Node.js with wrtc or similar polyfills
+   *
+   * @example Node.js with wrtc
+   * ```typescript
+   * import { RTCPeerConnection } from 'wrtc';
+   * const client = new Rondevu({ RTCPeerConnection });
+   * ```
+   */
+  RTCPeerConnection?: typeof RTCPeerConnection;
+
+  /**
+   * Custom RTCSessionDescription implementation for Node.js environments
+   * Required when using in Node.js with wrtc or similar polyfills
+   *
+   * @example Node.js with wrtc
+   * ```typescript
+   * import { RTCSessionDescription } from 'wrtc';
+   * const client = new Rondevu({ RTCSessionDescription });
+   * ```
+   */
+  RTCSessionDescription?: typeof RTCSessionDescription;
+
+  /**
+   * Custom RTCIceCandidate implementation for Node.js environments
+   * Required when using in Node.js with wrtc or similar polyfills
+   *
+   * @example Node.js with wrtc
+   * ```typescript
+   * import { RTCIceCandidate } from 'wrtc';
+   * const client = new Rondevu({ RTCIceCandidate });
+   * ```
+   */
+  RTCIceCandidate?: typeof RTCIceCandidate;
 }
 
 export class Rondevu {
   readonly auth: RondevuAuth;
+  readonly usernames: RondevuUsername;
+
   private _offers?: RondevuOffers;
   private credentials?: Credentials;
   private baseUrl: string;
   private fetchFn?: FetchFunction;
+  private rtcPeerConnection?: typeof RTCPeerConnection;
+  private rtcSessionDescription?: typeof RTCSessionDescription;
+  private rtcIceCandidate?: typeof RTCIceCandidate;
 
   constructor(options: RondevuOptions = {}) {
     this.baseUrl = options.baseUrl || 'https://api.ronde.vu';
     this.fetchFn = options.fetch;
+    this.rtcPeerConnection = options.RTCPeerConnection;
+    this.rtcSessionDescription = options.RTCSessionDescription;
+    this.rtcIceCandidate = options.RTCIceCandidate;
 
     this.auth = new RondevuAuth(this.baseUrl, this.fetchFn);
+    this.usernames = new RondevuUsername(this.baseUrl);
 
     if (options.credentials) {
       this.credentials = options.credentials;
@@ -47,7 +101,8 @@ export class Rondevu {
   }
 
   /**
-   * Get offers API (requires authentication)
+   * Get offers API (low-level access, requires authentication)
+   * For most use cases, use the durable connection APIs instead
    */
   get offers(): RondevuOffers {
     if (!this._offers) {
@@ -58,6 +113,7 @@ export class Rondevu {
 
   /**
    * Register and initialize authenticated client
+   * Generates a cryptographically random peer ID (128-bit)
    */
   async register(): Promise<Credentials> {
     this.credentials = await this.auth.register();
@@ -98,6 +154,143 @@ export class Rondevu {
       throw new Error('Not authenticated. Call register() first or provide credentials.');
     }
 
-    return new RondevuPeer(this._offers, rtcConfig);
+    return new RondevuPeer(
+      this._offers,
+      rtcConfig,
+      undefined, // No existing peer connection
+      this.rtcPeerConnection,
+      this.rtcSessionDescription,
+      this.rtcIceCandidate
+    );
+  }
+
+  /**
+   * Expose a durable service with automatic reconnection and TTL refresh
+   *
+   * Creates a service that handles incoming connections with automatic
+   * reconnection and message queuing during network interruptions.
+   *
+   * @param config Service configuration
+   * @returns DurableService instance
+   *
+   * @example
+   * ```typescript
+   * const service = await client.exposeService({
+   *   username: 'alice',
+   *   privateKey: keypair.privateKey,
+   *   serviceFqn: 'chat@1.0.0',
+   *   poolSize: 10,
+   *   handler: (channel, connectionId) => {
+   *     channel.on('message', (data) => {
+   *       console.log('Received:', data);
+   *       channel.send(`Echo: ${data}`);
+   *     });
+   *   }
+   * });
+   *
+   * await service.start();
+   * ```
+   */
+  async exposeService(
+    config: DurableServiceConfig & {
+      handler: (channel: DurableChannel, connectionId: string) => void | Promise<void>;
+    }
+  ): Promise<DurableService> {
+    if (!this._offers || !this.credentials) {
+      throw new Error('Not authenticated. Call register() first or provide credentials.');
+    }
+
+    const service = new DurableService(
+      this._offers,
+      this.baseUrl,
+      this.credentials,
+      config.handler,
+      config
+    );
+
+    return service;
+  }
+
+  /**
+   * Create a durable connection to a service by username and service FQN
+   *
+   * Establishes a WebRTC connection with automatic reconnection and
+   * message queuing during network interruptions.
+   *
+   * @param username Username of the service provider
+   * @param serviceFqn Fully qualified service name
+   * @param config Optional connection configuration
+   * @returns DurableConnection instance
+   *
+   * @example
+   * ```typescript
+   * const connection = await client.connect('alice', 'chat@1.0.0', {
+   *   maxReconnectAttempts: 5
+   * });
+   *
+   * const channel = connection.createChannel('main');
+   * channel.on('message', (data) => {
+   *   console.log('Received:', data);
+   * });
+   *
+   * await connection.connect();
+   * channel.send('Hello!');
+   * ```
+   */
+  async connect(
+    username: string,
+    serviceFqn: string,
+    config?: DurableConnectionConfig
+  ): Promise<DurableConnection> {
+    if (!this._offers) {
+      throw new Error('Not authenticated. Call register() first or provide credentials.');
+    }
+
+    const connectionInfo: ConnectionInfo = {
+      username,
+      serviceFqn
+    };
+
+    return new DurableConnection(this._offers, connectionInfo, config);
+  }
+
+  /**
+   * Create a durable connection to a service by UUID
+   *
+   * Establishes a WebRTC connection with automatic reconnection and
+   * message queuing during network interruptions.
+   *
+   * @param uuid Service UUID
+   * @param config Optional connection configuration
+   * @returns DurableConnection instance
+   *
+   * @example
+   * ```typescript
+   * const connection = await client.connectByUuid('service-uuid-here', {
+   *   maxReconnectAttempts: 5
+   * });
+   *
+   * const channel = connection.createChannel('main');
+   * channel.on('message', (data) => {
+   *   console.log('Received:', data);
+   * });
+   *
+   * await connection.connect();
+   * channel.send('Hello!');
+   * ```
+   */
+  async connectByUuid(
+    uuid: string,
+    config?: DurableConnectionConfig
+  ): Promise<DurableConnection> {
+    if (!this._offers) {
+      throw new Error('Not authenticated. Call register() first or provide credentials.');
+    }
+
+    const connectionInfo: ConnectionInfo = {
+      uuid
+    };
+
+    return new DurableConnection(this._offers, connectionInfo, config);
   }
 }

src/service-pool.ts

@@ -0,0 +1,664 @@
+import { RondevuOffers, Offer } from './offers.js';
+import { RondevuUsername } from './usernames.js';
+import RondevuPeer from './peer/index.js';
+import { OfferPool, AnsweredOffer } from './offer-pool.js';
+
+/**
+ * Connection information for tracking active connections
+ */
+interface ConnectionInfo {
+  peer: RondevuPeer;
+  channel: RTCDataChannel;
+  connectedAt: number;
+  offerId: string;
+}
+
+/**
+ * Status information about the pool
+ */
+export interface PoolStatus {
+  /** Number of active offers in the pool */
+  activeOffers: number;
+
+  /** Number of currently connected peers */
+  activeConnections: number;
+
+  /** Total number of connections handled since start */
+  totalConnectionsHandled: number;
+
+  /** Number of failed offer creation attempts */
+  failedOfferCreations: number;
+}
+
+/**
+ * Configuration options for a pooled service
+ */
+export interface ServicePoolOptions {
+  /** Username that owns the service */
+  username: string;
+
+  /** Private key for signing service operations */
+  privateKey: string;
+
+  /** Fully qualified service name (e.g., com.example.chat@1.0.0) */
+  serviceFqn: string;
+
+  /** WebRTC configuration */
+  rtcConfig?: RTCConfiguration;
+
+  /** Whether the service is publicly discoverable */
+  isPublic?: boolean;
+
+  /** Optional metadata for the service */
+  metadata?: Record<string, any>;
+
+  /** Time-to-live for offers in milliseconds */
+  ttl?: number;
+
+  /** Handler invoked for each new connection */
+  handler: (channel: RTCDataChannel, peer: RondevuPeer, connectionId: string) => void;
+
+  /** Number of simultaneous open offers to maintain (default: 1) */
+  poolSize?: number;
+
+  /** Polling interval in milliseconds (default: 2000ms) */
+  pollingInterval?: number;
+
+  /** Callback for pool status updates */
+  onPoolStatus?: (status: PoolStatus) => void;
+
+  /** Error handler for pool operations */
+  onError?: (error: Error, context: string) => void;
+}
+
+/**
+ * Service handle with pool-specific methods
+ */
+export interface PooledServiceHandle {
+  /** Service ID */
+  serviceId: string;
+
+  /** Service UUID */
+  uuid: string;
+
+  /** Offer ID */
+  offerId: string;
+
+  /** Unpublish the service */
+  unpublish: () => Promise<void>;
+
+  /** Get current pool status */
+  getStatus: () => PoolStatus;
+
+  /** Manually add offers to the pool */
+  addOffers: (count: number) => Promise<void>;
+}
+
+/**
+ * Manages a pooled service with multiple concurrent connections
+ *
+ * ServicePool coordinates offer creation, answer polling, and connection
+ * management for services that need to handle multiple simultaneous connections.
+ */
+export class ServicePool {
+  private offerPool?: OfferPool;
+  private connections: Map<string, ConnectionInfo> = new Map();
+  private peerConnections: Map<string, RTCPeerConnection> = new Map();
+  private status: PoolStatus = {
+    activeOffers: 0,
+    activeConnections: 0,
+    totalConnectionsHandled: 0,
+    failedOfferCreations: 0
+  };
+  private serviceId?: string;
+  private uuid?: string;
+  private offersApi: RondevuOffers;
+  private usernameApi: RondevuUsername;
+
+  constructor(
+    private baseUrl: string,
+    private credentials: { peerId: string; secret: string },
+    private options: ServicePoolOptions
+  ) {
+    this.offersApi = new RondevuOffers(baseUrl, credentials);
+    this.usernameApi = new RondevuUsername(baseUrl);
+  }
+
+  /**
+   * Start the pooled service
+   */
+  async start(): Promise<PooledServiceHandle> {
+    const poolSize = this.options.poolSize || 1;
+
+    // 1. Create initial service (publishes first offer)
+    const service = await this.publishInitialService();
+    this.serviceId = service.serviceId;
+    this.uuid = service.uuid;
+
+    // 2. Create additional offers for pool (poolSize - 1)
+    const additionalOffers: Offer[] = [];
+    const additionalPeerConnections: RTCPeerConnection[] = [];
+    const additionalDataChannels: RTCDataChannel[] = [];
+    if (poolSize > 1) {
+      try {
+        const result = await this.createOffers(poolSize - 1);
+        additionalOffers.push(...result.offers);
+        additionalPeerConnections.push(...result.peerConnections);
+        additionalDataChannels.push(...result.dataChannels);
+      } catch (error) {
+        this.handleError(error as Error, 'initial-offer-creation');
+      }
+    }
+
+    // 3. Initialize OfferPool with all offers
+    this.offerPool = new OfferPool(this.offersApi, {
+      poolSize,
+      pollingInterval: this.options.pollingInterval || 2000,
+      onAnswered: (answer) => this.handleConnection(answer),
+      onRefill: (count) => this.createOffers(count),
+      onError: (err, ctx) => this.handleError(err, ctx)
+    });
+
+    // Add all offers to pool with their peer connections and data channels
+    const allOffers = [
+      { id: service.offerId, peerId: this.credentials.peerId, sdp: service.offerSdp, topics: [], expiresAt: service.expiresAt, lastSeen: Date.now() },
+      ...additionalOffers
+    ];
+    const allPeerConnections = [
+      service.peerConnection,
+      ...additionalPeerConnections
+    ];
+    const allDataChannels = [
+      service.dataChannel,
+      ...additionalDataChannels
+    ];
+    await this.offerPool.addOffers(allOffers, allPeerConnections, allDataChannels);
+
+    // 4. Start polling
+    await this.offerPool.start();
+
+    // Update status
+    this.updateStatus();
+
+    // 5. Return handle
+    return {
+      serviceId: this.serviceId,
+      uuid: this.uuid,
+      offerId: service.offerId,
+      unpublish: () => this.stop(),
+      getStatus: () => this.getStatus(),
+      addOffers: (count) => this.manualRefill(count)
+    };
+  }
+
+  /**
+   * Stop the pooled service and clean up
+   */
+  async stop(): Promise<void> {
+    // 1. Stop accepting new connections
+    if (this.offerPool) {
+      await this.offerPool.stop();
+    }
+
+    // 2. Close peer connections from the pool
+    if (this.offerPool) {
+      const poolPeerConnections = this.offerPool.getActivePeerConnections();
+      poolPeerConnections.forEach(pc => {
+        try {
+          pc.close();
+        } catch {
+          // Ignore errors during cleanup
+        }
+      });
+    }
+
+    // 3. Delete remaining offers
+    if (this.offerPool) {
+      const offerIds = this.offerPool.getActiveOfferIds();
+      await Promise.allSettled(
+        offerIds.map(id => this.offersApi.delete(id).catch(() => {}))
+      );
+    }
+
+    // 4. Close active connections
+    const closePromises = Array.from(this.connections.values()).map(
+      async (conn) => {
+        try {
+          // Give a brief moment for graceful closure
+          await new Promise(resolve => setTimeout(resolve, 100));
+          conn.peer.pc.close();
+        } catch {
+          // Ignore errors during cleanup
+        }
+      }
+    );
+    await Promise.allSettled(closePromises);
+
+    // 5. Delete service if we have a serviceId
+    if (this.serviceId) {
+      try {
+        const response = await fetch(`${this.baseUrl}/services/${this.serviceId}`, {
+          method: 'DELETE',
+          headers: {
+            'Content-Type': 'application/json',
+            'Authorization': `Bearer ${this.credentials.peerId}:${this.credentials.secret}`
+          },
+          body: JSON.stringify({ username: this.options.username })
+        });
+
+        if (!response.ok) {
+          console.error('Failed to delete service:', await response.text());
+        }
+      } catch (error) {
+        console.error('Error deleting service:', error);
+      }
+    }
+
+    // Clear all state
+    this.connections.clear();
+    this.offerPool = undefined;
+  }
+
+  /**
+   * Handle an answered offer by setting up the connection
+   */
+  private async handleConnection(answer: AnsweredOffer): Promise<void> {
+    const connectionId = this.generateConnectionId();
+
+    try {
+      // Use the existing peer connection from the pool
+      const peer = new RondevuPeer(
+        this.offersApi,
+        this.options.rtcConfig || {
+          iceServers: [{ urls: 'stun:stun.l.google.com:19302' }]
+        },
+        answer.peerConnection // Use the existing peer connection
+      );
+
+      peer.role = 'offerer';
+      peer.offerId = answer.offerId;
+
+      // Verify peer connection is in correct state
+      if (peer.pc.signalingState !== 'have-local-offer') {
+        console.error('Peer connection state info:', {
+          signalingState: peer.pc.signalingState,
+          connectionState: peer.pc.connectionState,
+          iceConnectionState: peer.pc.iceConnectionState,
+          iceGatheringState: peer.pc.iceGatheringState,
+          hasLocalDescription: !!peer.pc.localDescription,
+          hasRemoteDescription: !!peer.pc.remoteDescription,
+          localDescriptionType: peer.pc.localDescription?.type,
+          remoteDescriptionType: peer.pc.remoteDescription?.type,
+          offerId: answer.offerId
+        });
+        throw new Error(
+          `Invalid signaling state: ${peer.pc.signalingState}. Expected 'have-local-offer' to set remote answer.`
+        );
+      }
+
+      // Set remote description (the answer)
+      await peer.pc.setRemoteDescription({
+        type: 'answer',
+        sdp: answer.sdp
+      });
+
+      // Use the data channel we created when making the offer
+      if (!answer.dataChannel) {
+        throw new Error('No data channel found for answered offer');
+      }
+
+      const channel = answer.dataChannel;
+
+      // Wait for the channel to open (it was created when we made the offer)
+      if (channel.readyState !== 'open') {
+        await new Promise<void>((resolve, reject) => {
+          const timeout = setTimeout(
+            () => reject(new Error('Timeout waiting for data channel to open')),
+            30000
+          );
+
+          channel.onopen = () => {
+            clearTimeout(timeout);
+            resolve();
+          };
+
+          channel.onerror = (error) => {
+            clearTimeout(timeout);
+            reject(new Error('Data channel error'));
+          };
+        });
+      }
+
+      // Register connection
+      this.connections.set(connectionId, {
+        peer,
+        channel,
+        connectedAt: Date.now(),
+        offerId: answer.offerId
+      });
+
+      this.status.activeConnections++;
+      this.status.totalConnectionsHandled++;
+
+      // Setup cleanup on disconnect
+      peer.on('disconnected', () => {
+        this.connections.delete(connectionId);
+        this.status.activeConnections--;
+        this.updateStatus();
+      });
+
+      peer.on('failed', () => {
+        this.connections.delete(connectionId);
+        this.status.activeConnections--;
+        this.updateStatus();
+      });
+
+      // Update status
+      this.updateStatus();
+
+      // Invoke user handler (wrapped in try-catch)
+      try {
+        this.options.handler(channel, peer, connectionId);
+      } catch (handlerError) {
+        this.handleError(handlerError as Error, 'handler');
+      }
+
+    } catch (error) {
+      this.handleError(error as Error, 'connection-setup');
+    }
+  }
+
+  /**
+   * Create multiple offers
+   */
+  private async createOffers(count: number): Promise<{ offers: Offer[], peerConnections: RTCPeerConnection[], dataChannels: RTCDataChannel[] }> {
+    if (count <= 0) {
+      return { offers: [], peerConnections: [], dataChannels: [] };
+    }
+
+    // Server supports max 10 offers per request
+    const batchSize = Math.min(count, 10);
+    const offers: Offer[] = [];
+    const peerConnections: RTCPeerConnection[] = [];
+    const dataChannels: RTCDataChannel[] = [];
+
+    try {
+      // Create peer connections and generate offers
+      const offerRequests = [];
+      const pendingCandidates: RTCIceCandidateInit[][] = []; // Store candidates before we have offer IDs
+
+      for (let i = 0; i < batchSize; i++) {
+        const pc = new RTCPeerConnection(this.options.rtcConfig || {
+          iceServers: [{ urls: 'stun:stun.l.google.com:19302' }]
+        });
+
+        // Create data channel (required for offers) and save reference
+        const channel = pc.createDataChannel('rondevu-service');
+        dataChannels.push(channel);
+
+        // Set up temporary candidate collector BEFORE setLocalDescription
+        const candidatesForThisOffer: RTCIceCandidateInit[] = [];
+        pendingCandidates.push(candidatesForThisOffer);
+
+        pc.onicecandidate = (event) => {
+          if (event.candidate) {
+            const candidateData = event.candidate.toJSON();
+            if (candidateData.candidate && candidateData.candidate !== '') {
+              const type = candidateData.candidate.includes('typ host') ? 'host' :
+                           candidateData.candidate.includes('typ srflx') ? 'srflx' :
+                           candidateData.candidate.includes('typ relay') ? 'relay' : 'unknown';
+              console.log(`🧊 Service pool generated ${type} ICE candidate:`, candidateData.candidate);
+              candidatesForThisOffer.push(candidateData);
+            }
+          } else {
+            console.log('🧊 Service pool ICE gathering complete');
+          }
+        };
+
+        // Create offer
+        const offer = await pc.createOffer();
+        await pc.setLocalDescription(offer); // ICE gathering starts here, candidates go to collector
+
+        if (!offer.sdp) {
+          pc.close();
+          throw new Error('Failed to generate SDP');
+        }
+
+        offerRequests.push({
+          sdp: offer.sdp,
+          topics: [], // V2 doesn't use topics
+          ttl: this.options.ttl
+        });
+
+        // Keep peer connection alive - DO NOT CLOSE
+        peerConnections.push(pc);
+      }
+
+      // Batch create offers
+      const createdOffers = await this.offersApi.create(offerRequests);
+      offers.push(...createdOffers);
+
+      // Now send all pending candidates and set up handlers for future ones
+      for (let i = 0; i < peerConnections.length; i++) {
+        const pc = peerConnections[i];
+        const offerId = createdOffers[i].id;
+        const candidates = pendingCandidates[i];
+
+        // Send any candidates that were collected while waiting for offer ID
+        if (candidates.length > 0) {
+          console.log(`📤 Sending ${candidates.length} pending ICE candidate(s) for offer ${offerId}`);
+          try {
+            await this.offersApi.addIceCandidates(offerId, candidates);
+            console.log(`✅ Sent ${candidates.length} pending ICE candidate(s)`);
+          } catch (err) {
+            console.error('❌ Error sending pending ICE candidates:', err);
+          }
+        }
+
+        // Replace temporary handler with permanent one for any future candidates
+        pc.onicecandidate = async (event) => {
+          if (event.candidate) {
+            const candidateData = event.candidate.toJSON();
+            if (candidateData.candidate && candidateData.candidate !== '') {
+              const type = candidateData.candidate.includes('typ host') ? 'host' :
+                           candidateData.candidate.includes('typ srflx') ? 'srflx' :
+                           candidateData.candidate.includes('typ relay') ? 'relay' : 'unknown';
+              console.log(`🧊 Service pool generated late ${type} ICE candidate:`, candidateData.candidate);
+              try {
+                await this.offersApi.addIceCandidates(offerId, [candidateData]);
+                console.log(`✅ Sent late ${type} ICE candidate`);
+              } catch (err) {
+                console.error(`❌ Error sending ${type} ICE candidate:`, err);
+              }
+            }
+          }
+        };
+      }
+
+    } catch (error) {
+      // Close any created peer connections on error
+      peerConnections.forEach(pc => pc.close());
+      this.status.failedOfferCreations++;
+      this.handleError(error as Error, 'offer-creation');
+      throw error;
+    }
+
+    return { offers, peerConnections, dataChannels };
+  }
+
+  /**
+   * Publish the initial service (creates first offer)
+   */
+  private async publishInitialService(): Promise<{
+    serviceId: string;
+    uuid: string;
+    offerId: string;
+    offerSdp: string;
+    expiresAt: number;
+    peerConnection: RTCPeerConnection;
+    dataChannel: RTCDataChannel;
+  }> {
+    const { username, privateKey, serviceFqn, rtcConfig, isPublic, metadata, ttl } = this.options;
+
+    // Create peer connection for initial offer
+    const pc = new RTCPeerConnection(rtcConfig || {
+      iceServers: [{ urls: 'stun:stun.l.google.com:19302' }]
+    });
+
+    const dataChannel = pc.createDataChannel('rondevu-service');
+
+    // Collect candidates before we have offer ID
+    const pendingCandidates: RTCIceCandidateInit[] = [];
+
+    // Set up temporary candidate collector BEFORE setLocalDescription
+    pc.onicecandidate = (event) => {
+      if (event.candidate) {
+        const candidateData = event.candidate.toJSON();
+        if (candidateData.candidate && candidateData.candidate !== '') {
+          const type = candidateData.candidate.includes('typ host') ? 'host' :
+                       candidateData.candidate.includes('typ srflx') ? 'srflx' :
+                       candidateData.candidate.includes('typ relay') ? 'relay' : 'unknown';
+          console.log(`🧊 Initial service generated ${type} ICE candidate:`, candidateData.candidate);
+          pendingCandidates.push(candidateData);
+        }
+      } else {
+        console.log('🧊 Initial service ICE gathering complete');
+      }
+    };
+
+    // Create offer
+    const offer = await pc.createOffer();
+    await pc.setLocalDescription(offer); // ICE gathering starts here
+
+    if (!offer.sdp) {
+      pc.close();
+      throw new Error('Failed to generate SDP');
+    }
+
+    // Store the SDP
+    const offerSdp = offer.sdp;
+
+    // Create signature
+    const timestamp = Date.now();
+    const message = `publish:${username}:${serviceFqn}:${timestamp}`;
+    const signature = await this.usernameApi.signMessage(message, privateKey);
+
+    // Publish service
+    const response = await fetch(`${this.baseUrl}/services`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        'Authorization': `Bearer ${this.credentials.peerId}:${this.credentials.secret}`
+      },
+      body: JSON.stringify({
+        username,
+        serviceFqn,
+        sdp: offerSdp,
+        ttl,
+        isPublic,
+        metadata,
+        signature,
+        message
+      })
+    });
+
+    if (!response.ok) {
+      pc.close();
+      const error = await response.json();
+      throw new Error(error.error || 'Failed to publish service');
+    }
+
+    const data = await response.json();
+
+    // Send any pending candidates
+    if (pendingCandidates.length > 0) {
+      console.log(`📤 Sending ${pendingCandidates.length} pending ICE candidate(s) for initial service`);
+      try {
+        await this.offersApi.addIceCandidates(data.offerId, pendingCandidates);
+        console.log(`✅ Sent ${pendingCandidates.length} pending ICE candidate(s)`);
+      } catch (err) {
+        console.error('❌ Error sending pending ICE candidates:', err);
+      }
+    }
+
+    // Set up handler for any future candidates
+    pc.onicecandidate = async (event) => {
+      if (event.candidate) {
+        const candidateData = event.candidate.toJSON();
+        if (candidateData.candidate && candidateData.candidate !== '') {
+          const type = candidateData.candidate.includes('typ host') ? 'host' :
+                       candidateData.candidate.includes('typ srflx') ? 'srflx' :
+                       candidateData.candidate.includes('typ relay') ? 'relay' : 'unknown';
+          console.log(`🧊 Initial service generated late ${type} ICE candidate:`, candidateData.candidate);
+          try {
+            await this.offersApi.addIceCandidates(data.offerId, [candidateData]);
+            console.log(`✅ Sent late ${type} ICE candidate`);
+          } catch (err) {
+            console.error(`❌ Error sending ${type} ICE candidate:`, err);
+          }
+        }
+      }
+    };
+
+    return {
+      serviceId: data.serviceId,
+      uuid: data.uuid,
+      offerId: data.offerId,
+      offerSdp,
+      expiresAt: data.expiresAt,
+      peerConnection: pc, // Keep peer connection alive
+      dataChannel // Keep data channel alive
+    };
+  }
+
+  /**
+   * Manually add offers to the pool
+   */
+  private async manualRefill(count: number): Promise<void> {
+    if (!this.offerPool) {
+      throw new Error('Pool not started');
+    }
+
+    const result = await this.createOffers(count);
+    await this.offerPool.addOffers(result.offers, result.peerConnections, result.dataChannels);
+    this.updateStatus();
+  }
+
+  /**
+   * Get current pool status
+   */
+  private getStatus(): PoolStatus {
+    return { ...this.status };
+  }
+
+  /**
+   * Update status and notify listeners
+   */
+  private updateStatus(): void {
+    if (this.offerPool) {
+      this.status.activeOffers = this.offerPool.getActiveOfferCount();
+    }
+
+    if (this.options.onPoolStatus) {
+      this.options.onPoolStatus(this.getStatus());
+    }
+  }
+
+  /**
+   * Handle errors
+   */
+  private handleError(error: Error, context: string): void {
+    if (this.options.onError) {
+      this.options.onError(error, context);
+    } else {
+      console.error(`ServicePool error (${context}):`, error);
+    }
+  }
+
+  /**
+   * Generate a unique connection ID
+   */
+  private generateConnectionId(): string {
+    return `conn-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
+  }
+}

src/types.ts

@@ -1,182 +0,0 @@
-// ============================================================================
-// Signaling Types
-// ============================================================================
-
-/**
- * Session side - identifies which peer in a connection
- */
-export type Side = 'offerer' | 'answerer';
-
-/**
- * Request body for POST /offer
- */
-export interface CreateOfferRequest {
-  /** Peer identifier/metadata (max 1024 characters) */
-  peerId: string;
-  /** Signaling data for peer connection */
-  offer: string;
-  /** Optional custom connection code (if not provided, server generates UUID) */
-  code?: string;
-}
-
-/**
- * Response from POST /offer
- */
-export interface CreateOfferResponse {
-  /** Unique session identifier (UUID) */
-  code: string;
-}
-
-/**
- * Request body for POST /answer
- */
-export interface AnswerRequest {
-  /** Session UUID from the offer */
-  code: string;
-  /** Response signaling data (required if candidate not provided) */
-  answer?: string;
-  /** Additional signaling data (required if answer not provided) */
-  candidate?: string;
-  /** Which peer is sending the data */
-  side: Side;
-}
-
-/**
- * Response from POST /answer
- */
-export interface AnswerResponse {
-  success: boolean;
-}
-
-/**
- * Request body for POST /poll
- */
-export interface PollRequest {
-  /** Session UUID */
-  code: string;
-  /** Which side is polling */
-  side: Side;
-}
-
-/**
- * Response from POST /poll when side=offerer
- */
-export interface PollOffererResponse {
-  /** Answer from answerer (null if not yet received) */
-  answer: string | null;
-  /** Additional signaling data from answerer */
-  answerCandidates: string[];
-}
-
-/**
- * Response from POST /poll when side=answerer
- */
-export interface PollAnswererResponse {
-  /** Offer from offerer */
-  offer: string;
-  /** Additional signaling data from offerer */
-  offerCandidates: string[];
-}
-
-/**
- * Response from POST /poll (union type)
- */
-export type PollResponse = PollOffererResponse | PollAnswererResponse;
-
-/**
- * Response from GET / - server version information
- */
-export interface VersionResponse {
-  /** Git commit hash or version identifier */
-  version: string;
-}
-
-/**
- * Response from GET /health
- */
-export interface HealthResponse {
-  status: 'ok';
-  timestamp: number;
-  version: string;
-}
-
-/**
- * Error response structure
- */
-export interface ErrorResponse {
-  error: string;
-}
-
-/**
- * Client configuration options
- */
-export interface RondevuClientOptions {
-  /** Base URL of the Rondevu server (e.g., 'https://example.com') */
-  baseUrl: string;
-  /** Optional fetch implementation (for Node.js environments) */
-  fetch?: typeof fetch;
-}
-
-// ============================================================================
-// WebRTC Types
-// ============================================================================
-
-/**
- * WebRTC polyfill for Node.js and other non-browser platforms
- */
-export interface WebRTCPolyfill {
-  RTCPeerConnection: typeof RTCPeerConnection;
-  RTCSessionDescription: typeof RTCSessionDescription;
-  RTCIceCandidate: typeof RTCIceCandidate;
-}
-
-/**
- * Configuration options for Rondevu WebRTC client
- */
-export interface RondevuOptions {
-  /** Base URL of the Rondevu server (defaults to 'https://api.ronde.vu') */
-  baseUrl?: string;
-  /** Peer identifier (optional, auto-generated if not provided) */
-  peerId?: string;
-  /** Optional fetch implementation (for Node.js environments) */
-  fetch?: typeof fetch;
-  /** WebRTC configuration (ICE servers, etc.) */
-  rtcConfig?: RTCConfiguration;
-  /** Polling interval in milliseconds (default: 1000) */
-  pollingInterval?: number;
-  /** Connection timeout in milliseconds (default: 30000) */
-  connectionTimeout?: number;
-  /** WebRTC polyfill for Node.js (e.g., wrtc or @roamhq/wrtc) */
-  wrtc?: WebRTCPolyfill;
-}
-
-/**
- * Connection role - whether this peer is creating or answering
- */
-export type ConnectionRole = 'offerer' | 'answerer';
-
-/**
- * Parameters for creating a RondevuConnection
- */
-export interface RondevuConnectionParams {
-  id: string;
-  topic?: string;
-  role: ConnectionRole;
-  pc: RTCPeerConnection;
-  localPeerId: string;
-  remotePeerId: string;
-  pollingInterval: number;
-  connectionTimeout: number;
-  wrtc?: WebRTCPolyfill;
-}
-
-/**
- * Event map for RondevuConnection events
- */
-export interface RondevuConnectionEvents {
-  connect: () => void;
-  disconnect: () => void;
-  error: (error: Error) => void;
-  datachannel: (channel: RTCDataChannel) => void;
-  stream: (stream: MediaStream) => void;
-}

src/usernames.ts

@@ -0,0 +1,200 @@
+import * as ed25519 from '@noble/ed25519';
+
+// Set SHA-512 hash function for ed25519 (required in @noble/ed25519 v3+)
+// Uses built-in WebCrypto API which only provides async digest
+// We use the async ed25519 functions (signAsync, verifyAsync, getPublicKeyAsync)
+ed25519.hashes.sha512Async = async (message: Uint8Array) => {
+  return new Uint8Array(await crypto.subtle.digest('SHA-512', message as BufferSource));
+};
+
+/**
+ * Username claim result
+ */
+export interface UsernameClaimResult {
+  username: string;
+  publicKey: string;
+  privateKey: string;
+  claimedAt: number;
+  expiresAt: number;
+}
+
+/**
+ * Username availability check result
+ */
+export interface UsernameCheckResult {
+  username: string;
+  available: boolean;
+  claimedAt?: number;
+  expiresAt?: number;
+  publicKey?: string;
+}
+
+/**
+ * Convert Uint8Array to base64 string
+ */
+function bytesToBase64(bytes: Uint8Array): string {
+  const binString = Array.from(bytes, (byte) =>
+    String.fromCodePoint(byte)
+  ).join('');
+  return btoa(binString);
+}
+
+/**
+ * Convert base64 string to Uint8Array
+ */
+function base64ToBytes(base64: string): Uint8Array {
+  const binString = atob(base64);
+  return Uint8Array.from(binString, (char) => char.codePointAt(0)!);
+}
+
+/**
+ * Rondevu Username API
+ * Handles username claiming with Ed25519 cryptographic proof
+ */
+export class RondevuUsername {
+  constructor(private baseUrl: string) {}
+
+  /**
+   * Generates an Ed25519 keypair for username claiming
+   */
+  async generateKeypair(): Promise<{ publicKey: string; privateKey: string }> {
+    const privateKey = ed25519.utils.randomSecretKey();
+    const publicKey = await ed25519.getPublicKeyAsync(privateKey);
+
+    return {
+      publicKey: bytesToBase64(publicKey),
+      privateKey: bytesToBase64(privateKey)
+    };
+  }
+
+  /**
+   * Signs a message with an Ed25519 private key
+   */
+  async signMessage(message: string, privateKeyBase64: string): Promise<string> {
+    const privateKey = base64ToBytes(privateKeyBase64);
+    const encoder = new TextEncoder();
+    const messageBytes = encoder.encode(message);
+
+    const signature = await ed25519.signAsync(messageBytes, privateKey);
+    return bytesToBase64(signature);
+  }
+
+  /**
+   * Claims a username
+   * Generates a new keypair if one is not provided
+   */
+  async claimUsername(
+    username: string,
+    existingKeypair?: { publicKey: string; privateKey: string }
+  ): Promise<UsernameClaimResult> {
+    // Generate or use existing keypair
+    const keypair = existingKeypair || await this.generateKeypair();
+
+    // Create signed message
+    const timestamp = Date.now();
+    const message = `claim:${username}:${timestamp}`;
+    const signature = await this.signMessage(message, keypair.privateKey);
+
+    // Send claim request
+    const response = await fetch(`${this.baseUrl}/usernames/claim`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({
+        username,
+        publicKey: keypair.publicKey,
+        signature,
+        message
+      })
+    });
+
+    if (!response.ok) {
+      const error = await response.json();
+      throw new Error(error.error || 'Failed to claim username');
+    }
+
+    const data = await response.json();
+
+    return {
+      username: data.username,
+      publicKey: keypair.publicKey,
+      privateKey: keypair.privateKey,
+      claimedAt: data.claimedAt,
+      expiresAt: data.expiresAt
+    };
+  }
+
+  /**
+   * Checks if a username is available
+   */
+  async checkUsername(username: string): Promise<UsernameCheckResult> {
+    const response = await fetch(`${this.baseUrl}/usernames/${username}`);
+
+    if (!response.ok) {
+      throw new Error('Failed to check username');
+    }
+
+    const data = await response.json();
+
+    return {
+      username: data.username,
+      available: data.available,
+      claimedAt: data.claimedAt,
+      expiresAt: data.expiresAt,
+      publicKey: data.publicKey
+    };
+  }
+
+  /**
+   * Helper: Save keypair to localStorage
+   * WARNING: This stores the private key in localStorage which is not the most secure
+   * For production use, consider using IndexedDB with encryption or hardware security modules
+   */
+  saveKeypairToStorage(username: string, publicKey: string, privateKey: string): void {
+    const data = { username, publicKey, privateKey, savedAt: Date.now() };
+    localStorage.setItem(`rondevu:keypair:${username}`, JSON.stringify(data));
+  }
+
+  /**
+   * Helper: Load keypair from localStorage
+   */
+  loadKeypairFromStorage(username: string): { publicKey: string; privateKey: string } | null {
+    const stored = localStorage.getItem(`rondevu:keypair:${username}`);
+    if (!stored) return null;
+
+    try {
+      const data = JSON.parse(stored);
+      return { publicKey: data.publicKey, privateKey: data.privateKey };
+    } catch {
+      return null;
+    }
+  }
+
+  /**
+   * Helper: Delete keypair from localStorage
+   */
+  deleteKeypairFromStorage(username: string): void {
+    localStorage.removeItem(`rondevu:keypair:${username}`);
+  }
+
+  /**
+   * Export keypair as JSON string (for backup)
+   */
+  exportKeypair(publicKey: string, privateKey: string): string {
+    return JSON.stringify({
+      publicKey,
+      privateKey,
+      exportedAt: Date.now()
+    });
+  }
+
+  /**
+   * Import keypair from JSON string
+   */
+  importKeypair(json: string): { publicKey: string; privateKey: string } {
+    const data = JSON.parse(json);
+    if (!data.publicKey || !data.privateKey) {
+      throw new Error('Invalid keypair format');
+    }
+    return { publicKey: data.publicKey, privateKey: data.privateKey };
+  }
+}