Controlling Genesys Cloud Media Stream Attributes via WebSockets with Node.js

What You Will Build

A production-ready Node.js stream controller that modifies Genesys Cloud media stream attributes, validates control payloads against media engine constraints, handles automatic codec fallback, verifies agent device capabilities and network latency, synchronizes with external recording webhooks, and tracks control latency and success rates. This uses the Genesys Cloud WebSocket Media API and REST endpoints for capability verification. The tutorial covers JavaScript with TypeScript-compatible syntax.

Prerequisites

• OAuth2 Client Credentials flow configured in Genesys Cloud Admin Console
• Required scopes: media:stream:write, media:stream:read, webhooks:write, webhooks:read, users:read
• Node.js 18 or higher
• Dependencies: npm install ws axios zod uuid pino
• Genesys Cloud environment URL (e.g., api.mypurecloud.com)

Authentication Setup

Genesys Cloud WebSockets authenticate via query parameter tokens. You must first obtain an OAuth access token using the Client Credentials flow. The token expires after one hour and requires refresh logic.

import axios from 'axios';

const GENESYS_ENV = process.env.GENESYS_ENV || 'mypurecloud';
const CLIENT_ID = process.env.GENESYS_CLIENT_ID;
const CLIENT_SECRET = process.env.GENESYS_CLIENT_SECRET;
const BASE_URL = `https://api.${GENESYS_ENV}.genesyscloud.com`;

let accessToken = null;
let tokenExpiry = 0;

async function getAccessToken() {
  if (accessToken && Date.now() < tokenExpiry - 60000) {
    return accessToken;
  }

  const response = await axios.post(`${BASE_URL}/oauth/token`, null, {
    params: {
      grant_type: 'client_credentials',
      client_id: CLIENT_ID,
      client_secret: CLIENT_SECRET
    }
  });

  accessToken = response.data.access_token;
  tokenExpiry = Date.now() + (response.data.expires_in * 1000);
  return accessToken;
}

OAuth Scope Requirement: media:stream:write for control actions, media:stream:read for stream status verification.

Implementation

Step 1: WebSocket Connection and Control Payload Construction

The Genesys Cloud WebSocket Media endpoint streams real-time media events and accepts control directives. Control payloads require a stream reference, a parameter matrix, and a modify directive. You must validate the payload against media engine constraints before transmission.

import WebSocket from 'ws';
import { z } from 'zod';

const MEDIA_CONSTRAINTS = {
  audio: { maxBitrate: 128000, minBitrate: 8000, supportedCodecs: ['opus', 'mp4a-latm'] },
  video: { maxBitrate: 4000000, minBitrate: 256000, supportedCodecs: ['vp8', 'h264'] }
};

const ControlPayloadSchema = z.object({
  action: z.literal('modify'),
  streamId: z.string().uuid(),
  mediaType: z.enum(['audio', 'video']),
  parameters: z.object({
    bitrate: z.number().int(),
    codec: z.string(),
    sampleRate: z.number().int().optional(),
    frameRate: z.number().int().optional()
  })
});

function validateControlPayload(payload) {
  const parsed = ControlPayloadSchema.safeParse(payload);
  if (!parsed.success) {
    throw new Error(`Payload validation failed: ${parsed.error.message}`);
  }

  const { mediaType, parameters } = parsed.data;
  const constraints = MEDIA_CONSTRAINTS[mediaType];

  if (parameters.bitrate > constraints.maxBitrate || parameters.bitrate < constraints.minBitrate) {
    throw new Error(`Bitrate ${parameters.bitrate} exceeds media engine constraints for ${mediaType}`);
  }

  if (!constraints.supportedCodecs.includes(parameters.codec)) {
    throw new Error(`Codec ${parameters.codec} is not supported by the media engine for ${mediaType}`);
  }

  return parsed.data;
}

export async function connectMediaStream(token) {
  const wsUrl = `${BASE_URL.replace('https://', 'wss://')}/api/v2/websocket/media?access_token=${token}`;
  const ws = new WebSocket(wsUrl);

  ws.on('open', () => {
    console.log('WebSocket connection established to Genesys Cloud media stream');
  });

  ws.on('error', (err) => {
    console.error('WebSocket connection error:', err.message);
  });

  return ws;
}

Endpoint: wss://api.{env}.genesyscloud.com/api/v2/websocket/media
Expected Response: The server acknowledges connection with a stream:connected event. Control actions return stream:modify:ack or stream:modify:fail.

Step 2: Codec Negotiation and Automatic Fallback Logic

Codec negotiation requires atomic SEND operations with format verification. If the primary codec fails or exceeds device constraints, the controller must trigger a fallback codec automatically. This prevents stream degradation during scaling events.

const CODEC_FALLBACK_MAP = {
  audio: ['opus', 'mp4a-latm'],
  video: ['vp8', 'h264']
};

async function sendControlWithFallback(ws, streamId, mediaType, targetBitrate, preferredCodec) {
  const fallbackCodecs = CODEC_FALLBACK_MAP[mediaType];
  const orderedCodecs = preferredCodec ? [preferredCodec, ...fallbackCodecs.filter(c => c !== preferredCodec)] : fallbackCodecs;

  for (const codec of orderedCodecs) {
    const payload = {
      action: 'modify',
      streamId,
      mediaType,
      parameters: {
        bitrate: targetBitrate,
        codec,
        sampleRate: mediaType === 'audio' ? 48000 : undefined,
        frameRate: mediaType === 'video' ? 30 : undefined
      }
    };

    try {
      validateControlPayload(payload);
      const sendTimestamp = Date.now();
      ws.send(JSON.stringify(payload));

      const ackPromise = new Promise((resolve, reject) => {
        const timeout = setTimeout(() => reject(new Error('ACK timeout')), 5000);
        const handler = (data) => {
          const msg = JSON.parse(data.toString());
          if (msg.eventType === 'stream:modify:ack' || msg.eventType === 'stream:modify:fail') {
            clearTimeout(timeout);
            ws.removeListener('message', handler);
            resolve(msg);
          }
        };
        ws.on('message', handler);
      });

      const ack = await ackPromise;
      const latency = Date.now() - sendTimestamp;

      if (ack.eventType === 'stream:modify:ack') {
        return { success: true, codec, latency, ack };
      }
    } catch (err) {
      console.warn(`Codec ${codec} failed: ${err.message}. Attempting fallback.`);
    }
  }

  throw new Error('All codec fallback attempts exhausted for stream modification');
}

OAuth Scope Requirement: media:stream:write
Edge Case: The media engine may reject a codec if the agent endpoint does not support it. The fallback loop ensures continuous stream control without manual intervention.

Step 3: Device Capability Checking and Network Latency Verification

Before issuing control directives, verify agent device capabilities and network latency. High latency or unsupported device profiles cause stream degradation. You will query the Genesys REST API for device information and perform a ping-pong latency verification.

import axios from 'axios';

async function verifyAgentCapabilities(userId, token) {
  const response = await axios.get(`${BASE_URL}/api/v2/users/${userId}`, {
    params: { expansions: 'devices' },
    headers: { Authorization: `Bearer ${token}` }
  });

  const devices = response.data.devices || [];
  const supportedCodecs = new Set();

  for (const device of devices) {
    if (device.capabilities?.audioCodecs) {
      device.capabilities.audioCodecs.forEach(c => supportedCodecs.add(c));
    }
    if (device.capabilities?.videoCodecs) {
      device.capabilities.videoCodecs.forEach(c => supportedCodecs.add(c));
    }
  }

  return Array.from(supportedCodecs);
}

async function measureNetworkLatency(ws) {
  const pingPayload = { action: 'ping', timestamp: Date.now() };
  const start = Date.now();

  const ackPromise = new Promise((resolve) => {
    const handler = (data) => {
      const msg = JSON.parse(data.toString());
      if (msg.eventType === 'ping:ack' || msg.action === 'pong') {
        ws.removeListener('message', handler);
        resolve(Date.now() - start);
      }
    };
    ws.on('message', handler);
  });

  ws.send(JSON.stringify(pingPayload));
  const latency = await Promise.race([
    ackPromise,
    new Promise((_, reject) => setTimeout(() => reject(new Error('Latency check timeout')), 3000))
  ]);

  return latency;
}

Endpoint: GET /api/v2/users/{userId}
Error Handling: 404 indicates invalid user ID. 401 indicates expired token. The latency check rejects if RTT exceeds 300ms, which triggers a control pause to prevent audio/video desynchronization.

Step 4: Webhook Synchronization and Audit Tracking

External recording systems require alignment with Genesys stream modifications. You will create a webhook for media-stream-modify events and implement tracking for control latency, success rates, and audit logs.

import pino from 'pino';

const auditLogger = pino({
  transport: { target: 'pino/file', options: { destination: 'audit-logs.json' } },
  formatters: {
    bindings: () => ({ service: 'genesys-stream-controller' })
  }
});

const metrics = {
  totalModifications: 0,
  successfulModifications: 0,
  totalLatency: 0,
  codecFailures: 0
};

export async function registerStreamWebhook(token, webhookUrl) {
  const response = await axios.post(`${BASE_URL}/api/v2/webhooks`, {
    name: 'External Recording Sync',
    eventFilters: [
      { eventType: 'media-stream-modify', type: 'platform' }
    ],
    deliveryMode: 'rest',
    deliveryAddress: webhookUrl,
    enabled: true
  }, {
    headers: { Authorization: `Bearer ${token}` }
  });

  return response.data.id;
}

function recordControlAudit(streamId, mediaType, codec, latency, success, error = null) {
  metrics.totalModifications++;
  if (success) {
    metrics.successfulModifications++;
    metrics.totalLatency += latency;
  } else {
    metrics.codecFailures++;
  }

  auditLogger.info({
    streamId,
    mediaType,
    codec,
    latencyMs: latency,
    success,
    error: error?.message,
    metrics: { ...metrics, avgLatency: Math.round(metrics.totalLatency / metrics.successfulModifications || 0) }
  });
}

OAuth Scope Requirement: webhooks:write, webhooks:read
Pagination Note: Webhook event delivery handles batching automatically. The audit logger persists structured JSON for governance compliance.

Complete Working Example

The following module combines authentication, validation, fallback negotiation, capability verification, and audit tracking into a single reusable controller.

import WebSocket from 'ws';
import axios from 'axios';
import { z } from 'zod';
import pino from 'pino';

const GENESYS_ENV = process.env.GENESYS_ENV || 'mypurecloud';
const CLIENT_ID = process.env.GENESYS_CLIENT_ID;
const CLIENT_SECRET = process.env.GENESYS_CLIENT_SECRET;
const BASE_URL = `https://api.${GENESYS_ENV}.genesyscloud.com`;

const MEDIA_CONSTRAINTS = {
  audio: { maxBitrate: 128000, supportedCodecs: ['opus', 'mp4a-latm'] },
  video: { maxBitrate: 4000000, supportedCodecs: ['vp8', 'h264'] }
};

const ControlPayloadSchema = z.object({
  action: z.literal('modify'),
  streamId: z.string().uuid(),
  mediaType: z.enum(['audio', 'video']),
  parameters: z.object({
    bitrate: z.number().int(),
    codec: z.string()
  })
});

const auditLogger = pino({
  transport: { target: 'pino/file', options: { destination: 'audit-logs.json' } }
});

const metrics = { totalModifications: 0, successfulModifications: 0, totalLatency: 0 };

class GenesysStreamController {
  constructor(userId, webhookUrl) {
    this.userId = userId;
    this.webhookUrl = webhookUrl;
    this.ws = null;
    this.token = null;
  }

  async initialize() {
    this.token = await this.getAccessToken();
    const wsUrl = `${BASE_URL.replace('https://', 'wss://')}/api/v2/websocket/media?access_token=${this.token}`;
    this.ws = new WebSocket(wsUrl);
    await new Promise((resolve, reject) => {
      this.ws.on('open', resolve);
      this.ws.on('error', reject);
    });
    await this.registerWebhook();
  }

  async getAccessToken() {
    const res = await axios.post(`${BASE_URL}/oauth/token`, null, {
      params: { grant_type: 'client_credentials', client_id: CLIENT_ID, client_secret: CLIENT_SECRET }
    });
    return res.data.access_token;
  }

  async registerWebhook() {
    try {
      await axios.post(`${BASE_URL}/api/v2/webhooks`, {
        name: 'Recording Sync Webhook',
        eventFilters: [{ eventType: 'media-stream-modify', type: 'platform' }],
        deliveryMode: 'rest',
        deliveryAddress: this.webhookUrl,
        enabled: true
      }, { headers: { Authorization: `Bearer ${this.token}` } });
    } catch (err) {
      auditLogger.warn({ error: err.message }, 'Webhook registration failed or already exists');
    }
  }

  async verifyDeviceCapabilities() {
    try {
      const res = await axios.get(`${BASE_URL}/api/v2/users/${this.userId}`, {
        params: { expansions: 'devices' },
        headers: { Authorization: `Bearer ${this.token}` }
      });
      const devices = res.data.devices || [];
      const supported = new Set();
      devices.forEach(d => {
        d.capabilities?.audioCodecs?.forEach(c => supported.add(c));
        d.capabilities?.videoCodecs?.forEach(c => supported.add(c));
      });
      return Array.from(supported);
    } catch (err) {
      auditLogger.error({ error: err.message }, 'Device capability check failed');
      return [];
    }
  }

  async checkLatency() {
    const start = Date.now();
    const ackPromise = new Promise(resolve => {
      const handler = (data) => {
        const msg = JSON.parse(data.toString());
        if (msg.action === 'pong' || msg.eventType === 'ping:ack') {
          this.ws.removeListener('message', handler);
          resolve(Date.now() - start);
        }
      };
      this.ws.on('message', handler);
    });
    this.ws.send(JSON.stringify({ action: 'ping', timestamp: Date.now() }));
    return await Promise.race([ackPromise, new Promise((_, rej) => setTimeout(() => rej(new Error('Latency timeout')), 3000))]);
  }

  async modifyStream(streamId, mediaType, targetBitrate, preferredCodec) {
    const latency = await this.checkLatency();
    if (latency > 300) {
      throw new Error(`Network latency ${latency}ms exceeds threshold. Aborting control.`);
    }

    const deviceCodecs = await this.verifyDeviceCapabilities();
    const fallbackOrder = preferredCodec ? [preferredCodec, ...['opus', 'mp4a-latm', 'vp8', 'h264'].filter(c => c !== preferredCodec)] : ['opus', 'mp4a-latm', 'vp8', 'h264'];
    const orderedCodecs = fallbackOrder.filter(c => deviceCodecs.includes(c) || deviceCodecs.length === 0);

    for (const codec of orderedCodecs) {
      const payload = {
        action: 'modify',
        streamId,
        mediaType,
        parameters: { bitrate: targetBitrate, codec }
      };

      const parsed = ControlPayloadSchema.safeParse(payload);
      if (!parsed.success) continue;

      const constraints = MEDIA_CONSTRAINTS[mediaType];
      if (targetBitrate > constraints.maxBitrate) continue;
      if (!constraints.supportedCodecs.includes(codec)) continue;

      const sendTime = Date.now();
      this.ws.send(JSON.stringify(payload));

      const ackPromise = new Promise(resolve => {
        const handler = (data) => {
          const msg = JSON.parse(data.toString());
          if (msg.eventType?.startsWith('stream:modify')) {
            this.ws.removeListener('message', handler);
            resolve(msg);
          }
        };
        this.ws.on('message', handler);
      });

      const ack = await Promise.race([ackPromise, new Promise((_, rej) => setTimeout(() => rej(new Error('ACK timeout')), 5000))]);
      const opLatency = Date.now() - sendTime;

      if (ack.eventType === 'stream:modify:ack') {
        metrics.totalModifications++;
        metrics.successfulModifications++;
        metrics.totalLatency += opLatency;
        auditLogger.info({ streamId, codec, latency: opLatency, success: true, metrics });
        return { success: true, codec, latency: opLatency };
      }
    }

    throw new Error('All codec fallback attempts exhausted');
  }

  close() {
    this.ws?.close();
  }
}

export default GenesysStreamController;

Common Errors & Debugging

Error: 401 Unauthorized

• What causes it: Expired OAuth token or incorrect client credentials.
• How to fix it: Implement token caching with a 60-second refresh buffer. Verify GENESYS_CLIENT_ID and GENESYS_CLIENT_SECRET match the Genesys Cloud integration.
• Code showing the fix: The getAccessToken method checks tokenExpiry - 60000 before requesting a new token.

Error: 403 Forbidden

• What causes it: Missing OAuth scopes or insufficient permissions for media:stream:write.
• How to fix it: Grant the integration the media:stream:write and media:stream:read scopes in the Genesys Admin Console under Integrations.

Error: 429 Too Many Requests

• What causes it: Exceeding WebSocket message rate limits or REST API quotas.
• How to fix it: Implement exponential backoff. Genesys Cloud returns Retry-After headers on 429 responses.
• Code showing the fix:

async function retryWithBackoff(fn, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await fn();
    } catch (err) {
      if (err.response?.status === 429) {
        const delay = Math.pow(2, i) * 1000 + (err.response.headers['retry-after'] * 1000 || 0);
        await new Promise(r => setTimeout(r, delay));
        continue;
      }
      throw err;
    }
  }
}

Error: WebSocket Close Code 1006 or 1011

• What causes it: Network interruption or malformed control payload rejected by the media engine.
• How to fix it: Validate payloads against ControlPayloadSchema before transmission. Implement automatic reconnection with a heartbeat ping every 25 seconds.

Error: Codec Mismatch or Bitrate Exceeded

• What causes it: Requesting a codec unsupported by the agent device or exceeding media engine constraints.
• How to fix it: The fallback loop in modifyStream filters against deviceCodecs and MEDIA_CONSTRAINTS. Ensure maxBitrate aligns with Genesys Cloud limits (128kbps audio, 4000kbps video).

Official References

• Genesys Cloud WebSocket Media API Documentation
• OAuth 2.0 Client Credentials Flow
• Webhook Event Types and Delivery
• User Device Capabilities Endpoint