Mocking Genesys Cloud Data Actions External HTTP Calls with Node.js

What You Will Build

• A Node.js mock server that intercepts, validates, and simulates external HTTP calls triggered by Genesys Cloud Data Actions.
• The solution uses the Genesys Cloud Data Actions API (/api/v2/dataactions) and the @genesyscloud/purecloud-api-client SDK.
• The implementation covers Node.js with Express, WebSocket, Zod schema validation, and a circuit breaker pattern for safe mock iteration.

Prerequisites

• OAuth client type: Confidential Client or JWT Bearer Grant
• Required scopes: dataactions:read, dataactions:write, dataactions:execute, analytics:read
• SDK: @genesyscloud/purecloud-api-client v6.0.0 or higher
• Runtime: Node.js 18.0+
• External dependencies: express, ws, zod, axios, uuid, @types/node

Authentication Setup

Genesys Cloud requires OAuth 2.0 for all API access. The following code retrieves an access token using the client credentials grant. The token is cached with an expiry check to prevent unnecessary authentication requests.

import axios from 'axios';

const GENESYS_ENV = 'https://api.mypurecloud.com';
const CLIENT_ID = process.env.GENESYS_CLIENT_ID;
const CLIENT_SECRET = process.env.GENESYS_CLIENT_SECRET;

let cachedToken = null;
let tokenExpiry = 0;

async function getAccessToken() {
  const now = Date.now();
  if (cachedToken && now < tokenExpiry) {
    return cachedToken;
  }

  const url = `${GENESYS_ENV}/oauth/token`;
  const params = new URLSearchParams({
    grant_type: 'client_credentials',
    client_id: CLIENT_ID,
    client_secret: CLIENT_SECRET,
    scope: 'dataactions:read dataactions:write dataactions:execute analytics:read'
  });

  const response = await axios.post(url, params, {
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' }
  });

  cachedToken = response.data.access_token;
  tokenExpiry = now + (response.data.expires_in * 1000) - 5000;
  return cachedToken;
}

The request targets /oauth/token with application/x-www-form-urlencoded encoding. The response contains access_token and expires_in. The cache window subtracts five seconds to account for network latency. If the endpoint returns 401, the credentials are invalid. If it returns 429, implement exponential backoff before retrying.

Implementation

Step 1: Configure the Stub Matrix and Intercept Directive

The mock server uses a stub-matrix configuration object to map endpoint-ref paths to response payloads. An intercept directive middleware captures incoming requests before standard routing, enabling header inspection and status code evaluation.

import express from 'express';
import { v4 as uuidv4 } from 'uuid';

const app = express();
app.use(express.json({ limit: '5mb' }));

const STUB_MATRIX = {
  '/external/customer-lookup': {
    status: 200,
    headers: { 'X-Mock-Source': 'stub-matrix' },
    body: { customerId: 'C-88219', tier: 'premium', verified: true }
  },
  '/external/inventory-check': {
    status: 204,
    headers: { 'X-Mock-Source': 'stub-matrix' },
    body: null
  }
};

const interceptDirective = (req, res, next) => {
  const route = req.path;
  const stub = STUB_MATRIX[route];

  if (!stub) {
    const error = new Error(`Unhandled route: ${route}`);
    error.code = 'MOCK_ROUTE_MISSING';
    return next(error);
  }

  req.mockContext = {
    requestId: uuidv4(),
    timestamp: new Date().toISOString(),
    stubConfig: stub,
    latencyStart: process.hrtime.bigint()
  };
  next();
};

app.use(interceptDirective);

The interceptDirective middleware validates the request path against the stub-matrix. If the route is unhandled, it passes a structured error to the error handler. The middleware attaches a mockContext object containing a unique request identifier, timestamp, and a high-resolution latency marker. This context flows through subsequent validation pipelines.

Step 2: Schema Validation, Size Limits, and Header Evaluation

Mock payloads must comply with testing constraints. The following pipeline validates incoming request bodies against Zod schemas, enforces maximum response size limits, and calculates safe header values.

import { z } from 'zod';

const MOCK_RESPONSE_SCHEMA = z.object({
  status: z.number().int().min(100).max(599),
  headers: z.record(z.string()).optional(),
  body: z.any().nullable()
});

const MAX_RESPONSE_BYTES = 5 * 1024 * 1024; // 5MB

function validateMockPayload(config) {
  const result = MOCK_RESPONSE_SCHEMA.safeParse(config);
  if (!result.success) {
    throw new Error(`Schema validation failed: ${result.error.message}`);
  }
  return result.data;
}

function calculateSafeHeaders(headers) {
  const sanitized = {};
  for (const [key, value] of Object.entries(headers || {})) {
    const safeKey = key.replace(/[^a-zA-Z0-9\-_]/g, '');
    if (safeKey.toLowerCase() === 'host' || safeKey.toLowerCase() === 'content-length') continue;
    sanitized[safeKey] = value;
  }
  return sanitized;
}

app.post('/api/mocks/:route', (req, res) => {
  try {
    const config = req.mockContext.stubConfig;
    const validated = validateMockPayload(config);
    const safeHeaders = calculateSafeHeaders(validated.headers);
    const bodyBytes = validated.body ? Buffer.byteLength(JSON.stringify(validated.body)) : 0;

    if (bodyBytes > MAX_RESPONSE_BYTES) {
      throw new Error(`Response size ${bodyBytes} exceeds maximum limit of ${MAX_RESPONSE_BYTES}`);
    }

    const latencyEnd = process.hrtime.bigint();
    const latencyMs = Number(latencyEnd - req.mockContext.latencyStart) / 1e6;

    res.status(validated.status)
      .set(safeHeaders)
      .json(validated.body);

    recordMetric(req.mockContext.requestId, latencyMs, true);
  } catch (error) {
    handleError(error, req, res);
  }
});

The pipeline parses the stub configuration through MOCK_RESPONSE_SCHEMA. It strips unsafe header keys to prevent HTTP response splitting. It measures payload size in bytes and rejects responses exceeding five megabytes. The recordMetric function tracks latency and success state for later reporting.

Step 3: WebSocket Synchronization and Circuit Breaker Logic

Test runners require real-time synchronization. A WebSocket server broadcasts mock events. An atomic message queue prevents race conditions during concurrent test execution. A circuit breaker halts mock iteration when failure thresholds are exceeded.

import WebSocket from 'ws';
import { EventEmitter } from 'events';

const wss = new WebSocket.Server({ noServer: true });
const metricsStore = new Map();
const circuitBreaker = { failures: 0, threshold: 5, state: 'closed', lastTrip: 0 };

function recordMetric(requestId, latencyMs, success) {
  metricsStore.set(requestId, { latencyMs, success, timestamp: Date.now() });
  if (!success) {
    circuitBreaker.failures++;
    if (circuitBreaker.failures >= circuitBreaker.threshold) {
      circuitBreaker.state = 'open';
      circuitBreaker.lastTrip = Date.now();
      broadcastEvent('circuit_breaker_tripped', { failures: circuitBreaker.failures });
    }
  }
}

function broadcastEvent(type, payload) {
  const message = JSON.stringify({ type, payload, timestamp: new Date().toISOString() });
  wss.clients.forEach(client => {
    if (client.readyState === WebSocket.OPEN) {
      client.send(message);
    }
  });
}

const messageQueue = [];
let processing = false;

function processWebSocketMessages() {
  if (processing) return;
  processing = true;
  while (messageQueue.length > 0) {
    const msg = messageQueue.shift();
    try {
      const parsed = JSON.parse(msg);
      if (!parsed.type || !parsed.payload) throw new Error('Invalid message format');
      broadcastEvent('test_sync', parsed);
    } catch (err) {
      console.error('WebSocket format verification failed:', err.message);
    }
  }
  processing = false;
}

wss.on('connection', (ws) => {
  ws.on('message', (data) => {
    messageQueue.push(data.toString());
    setImmediate(processWebSocketMessages);
  });
});

The messageQueue array and processing flag create an atomic execution context for WebSocket text operations. Each message undergoes format verification before broadcasting. The circuit breaker tracks consecutive failures and transitions to an open state when the threshold is reached. This prevents cascading mock failures during scaling tests.

Step 4: Data Actions API Integration and Endpoint Reference Mapping

The Genesys Cloud SDK creates or updates a Data Action that references the mock server. The endpoint-ref field points to the mock route. The implementation includes retry logic for 429 rate limit responses.

import { ApiClient, DataActionsApi } from '@genesyscloud/purecloud-api-client';

const apiClient = new ApiClient();
const dataActionsApi = new DataActionsApi();

async function updateDataAction(actionId, mockBaseUrl) {
  const token = await getAccessToken();
  apiClient.setAccessToken(token);

  const action = await dataActionsApi.getDataActionsDataAction(actionId);
  
  action.endpointRef = `${mockBaseUrl}/api/mocks/external/customer-lookup`;
  action.method = 'POST';
  action.timeoutSeconds = 10;
  action.retryCount = 0;

  let attempts = 0;
  const maxRetries = 3;
  let lastError = null;

  while (attempts < maxRetries) {
    try {
      const response = await dataActionsApi.putDataActionsDataAction(actionId, action);
      console.log('Data Action updated successfully:', response.data.id);
      return response.data;
    } catch (error) {
      lastError = error;
      if (error.response && error.response.status === 429) {
        const retryAfter = error.response.headers['retry-after'] || Math.pow(2, attempts);
        console.warn(`Rate limited. Retrying in ${retryAfter} seconds...`);
        await new Promise(resolve => setTimeout(resolve, retryAfter * 1000));
        attempts++;
      } else {
        throw error;
      }
    }
  }
  throw lastError;
}

The putDataActionsDataAction call targets /api/v2/dataactions/{dataActionId}. The retry loop handles 429 responses by reading the retry-after header or applying exponential backoff. The endpointRef field directly maps to the mock server route defined in the stub-matrix. If the API returns 403, verify the OAuth scope includes dataactions:write.

Complete Working Example

The following script combines authentication, mock server configuration, WebSocket synchronization, and Data Actions API integration into a single executable module. Replace environment variables with valid credentials before execution.

import express from 'express';
import http from 'http';
import { WebSocketServer } from 'ws';
import { ApiClient, DataActionsApi } from '@genesyscloud/purecloud-api-client';
import axios from 'axios';
import { z } from 'zod';
import { v4 as uuidv4 } from 'uuid';

const GENESYS_ENV = process.env.GENESYS_ENV || 'https://api.mypurecloud.com';
const CLIENT_ID = process.env.GENESYS_CLIENT_ID;
const CLIENT_SECRET = process.env.GENESYS_CLIENT_SECRET;
const MOCK_PORT = process.env.MOCK_PORT || 3000;
const ACTION_ID = process.env.DATA_ACTION_ID;

let cachedToken = null;
let tokenExpiry = 0;

async function getAccessToken() {
  const now = Date.now();
  if (cachedToken && now < tokenExpiry) return cachedToken;
  const params = new URLSearchParams({
    grant_type: 'client_credentials',
    client_id: CLIENT_ID,
    client_secret: CLIENT_SECRET,
    scope: 'dataactions:read dataactions:write dataactions:execute analytics:read'
  });
  const res = await axios.post(`${GENESYS_ENV}/oauth/token`, params, {
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' }
  });
  cachedToken = res.data.access_token;
  tokenExpiry = now + (res.data.expires_in * 1000) - 5000;
  return cachedToken;
}

const app = express();
app.use(express.json({ limit: '5mb' }));

const STUB_MATRIX = {
  '/external/customer-lookup': { status: 200, headers: { 'X-Mock-Source': 'stub' }, body: { id: 'C-1', tier: 'gold' } },
  '/external/inventory-check': { status: 204, headers: {}, body: null }
};

const metricsStore = new Map();
const circuitBreaker = { failures: 0, threshold: 5, state: 'closed' };
const messageQueue = [];
let processing = false;

function recordMetric(id, latency, success) {
  metricsStore.set(id, { latency, success, ts: Date.now() });
  if (!success) {
    circuitBreaker.failures++;
    if (circuitBreaker.failures >= circuitBreaker.threshold) {
      circuitBreaker.state = 'open';
      broadcast('circuit_breaker_tripped', { failures: circuitBreaker.failures });
    }
  }
}

const wss = new WebSocketServer({ noServer: true });
function broadcast(type, payload) {
  const msg = JSON.stringify({ type, payload, ts: new Date().toISOString() });
  wss.clients.forEach(c => c.readyState === 1 && c.send(msg));
}

function processWs() {
  if (processing) return;
  processing = true;
  while (messageQueue.length) {
    const raw = messageQueue.shift();
    try {
      const p = JSON.parse(raw);
      if (p.type && p.payload) broadcast('test_sync', p);
    } catch (e) { console.error('WS format error:', e.message); }
  }
  processing = false;
}

const server = http.createServer(app);
server.on('upgrade', (req, socket, head) => {
  wss.handleUpgrade(req, socket, head, ws => wss.emit('connection', ws));
});

wss.on('connection', ws => {
  ws.on('message', data => { messageQueue.push(data.toString()); setImmediate(processWs); });
});

app.use((req, res, next) => {
  const stub = STUB_MATRIX[req.path];
  if (!stub) return next(new Error(`Unhandled route: ${req.path}`));
  req.ctx = { id: uuidv4(), start: process.hrtime.bigint(), stub };
  next();
});

app.post('/api/mocks/:route', (req, res) => {
  try {
    const { status, headers, body } = req.ctx.stub;
    const safeHeaders = Object.fromEntries(
      Object.entries(headers || {}).filter(([k]) => !['host', 'content-length'].includes(k.toLowerCase()))
    );
    const size = body ? Buffer.byteLength(JSON.stringify(body)) : 0;
    if (size > 5242880) throw new Error('Payload exceeds 5MB limit');
    
    const latency = Number(process.hrtime.bigint() - req.ctx.start) / 1e6;
    res.status(status).set(safeHeaders).json(body);
    recordMetric(req.ctx.id, latency, true);
    console.log(`[AUDIT] ${req.ctx.id} | ${req.path} | ${status} | ${latency.toFixed(2)}ms | SUCCESS`);
  } catch (err) {
    recordMetric(req.ctx.id || 'unknown', 0, false);
    console.error(`[AUDIT] ERROR | ${req.path} | ${err.message}`);
    res.status(500).json({ error: err.message });
  }
});

async function syncDataAction() {
  if (!ACTION_ID) return;
  const token = await getAccessToken();
  const api = new ApiClient();
  api.setAccessToken(token);
  const daApi = new DataActionsApi();
  
  let attempts = 0;
  while (attempts < 3) {
    try {
      const act = await daApi.getDataActionsDataAction(ACTION_ID);
      act.endpointRef = `http://localhost:${MOCK_PORT}/api/mocks/external/customer-lookup`;
      const res = await daApi.putDataActionsDataAction(ACTION_ID, act);
      console.log('Data Action synced:', res.data.id);
      return;
    } catch (e) {
      if (e.response?.status === 429) {
        const wait = e.response.headers['retry-after'] || Math.pow(2, attempts);
        console.warn(`429 Rate limit. Waiting ${wait}s...`);
        await new Promise(r => setTimeout(r, wait * 1000));
        attempts++;
      } else throw e;
    }
  }
}

server.listen(MOCK_PORT, async () => {
  console.log(`Mock server running on port ${MOCK_PORT}`);
  await syncDataAction();
});

The script initializes the OAuth client, configures the Express router with intercept middleware, attaches the WebSocket server, implements the circuit breaker and metrics pipeline, and synchronizes the Genesys Cloud Data Action. Audit logs print to stdout with request identifiers, paths, status codes, and latency measurements.

Common Errors & Debugging

Error: 401 Unauthorized

• What causes it: Expired OAuth token or invalid client credentials.
• How to fix it: Verify GENESYS_CLIENT_ID and GENESYS_CLIENT_SECRET match a confidential client in Genesys Cloud. Ensure the token cache expiration logic subtracts a buffer window.
• Code showing the fix: The getAccessToken function already implements cache validation. Add a try/catch around the initial token request and throw a descriptive error if response.status === 401.

Error: 400 Bad Request (Schema Validation Failed)

• What causes it: The stub-matrix contains invalid status codes, non-string headers, or malformed JSON bodies.
• How to fix it: Run the MOCK_RESPONSE_SCHEMA validation before server startup. Correct type mismatches in the configuration object.
• Code showing the fix: Wrap STUB_MATRIX initialization in a validation loop that throws on !result.success before server.listen().

Error: 429 Rate Limit Exceeded

• What causes it: Excessive API calls to /api/v2/dataactions or /oauth/token.
• How to fix it: Implement exponential backoff with jitter. Respect the retry-after header.
• Code showing the fix: The syncDataAction function includes a retry loop that checks error.response.status === 429 and delays execution.

Error: Circuit Breaker Tripped

• What causes it: Five consecutive mock validation failures or unhandled routes.
• How to fix it: Review the audit logs for repeated Unhandled route or schema errors. Reset the circuit breaker by restarting the mock server or implementing a half-open state that allows a single probe request.
• Code showing the fix: Add a /reset-circuit endpoint that sets circuitBreaker.failures = 0 and circuitBreaker.state = 'closed'.

Official References

• Genesys Cloud Data Actions API Documentation
• Genesys Cloud OAuth 2.0 Authentication Guide
• Node.js SDK Reference (@genesyscloud/purecloud-api-client)
• Express.js Middleware and Error Handling
• WebSocket Protocol and Node.js ws Library