Sending Genesys Cloud Web Messaging Bot Messages via REST API with TypeScript

What You Will Build

• A TypeScript module that constructs, validates, and transmits bot messages to Genesys Cloud Conversations API endpoints with strict schema enforcement.
• A production-ready sender class that handles OAuth authentication, exponential backoff for rate limits, latency tracking, audit logging, and external CRM webhook synchronization.
• TypeScript code that enforces channel rendering constraints, maximum payload sizes, and cross-origin security pipelines before atomic message delivery.

Prerequisites

• OAuth 2.0 Client Credentials flow configured in Genesys Cloud with the conversation:write scope
• Genesys Cloud Conversations API v2 endpoint: /api/v2/conversations/{conversationId}/messages
• Node.js 18.0 or higher with native fetch support
• TypeScript 5.0 or higher with strict mode enabled
• No external npm dependencies required for the core implementation

Authentication Setup

Genesys Cloud requires a bearer token for all Conversations API calls. The client credentials flow returns a token valid for 300 seconds. The following code fetches the token, caches it in memory, and validates expiration before each request.

import * as crypto from 'crypto';

interface TokenCache {
  accessToken: string;
  expiresAt: number;
}

class GenesysAuthManager {
  private cache: TokenCache | null = null;

  constructor(
    private readonly orgUrl: string,
    private readonly clientId: string,
    private readonly clientSecret: string
  ) {}

  async getAccessToken(): Promise<string> {
    const now = Date.now();
    if (this.cache && now < this.cache.expiresAt - 10_000) {
      return this.cache.accessToken;
    }

    const tokenUrl = `${this.orgUrl}/oauth/token`;
    const body = new URLSearchParams({
      grant_type: 'client_credentials',
      client_id: this.clientId,
      client_secret: this.clientSecret,
      scope: 'conversation:write'
    });

    const response = await fetch(tokenUrl, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Accept': 'application/json'
      },
      body: body.toString()
    });

    if (!response.ok) {
      const errorText = await response.text();
      throw new Error(`OAuth token acquisition failed (${response.status}): ${errorText}`);
    }

    const data = await response.json() as { access_token: string; expires_in: number };
    this.cache = {
      accessToken: data.access_token,
      expiresAt: now + (data.expires_in * 1000)
    };

    return this.cache.accessToken;
  }
}

Implementation

Step 1: Payload Construction and Schema Validation

Genesys Cloud Conversations API enforces strict payload boundaries. Text messages must not exceed 4096 characters. Rich content requires explicit type matrices and card directive flags. The following validator enforces rendering constraints and strips injection vectors before transmission.

export type MessageType = 'text' | 'card' | 'quickReply';

export interface MessagePayload {
  to: { id: string };
  from: { id: string };
  type: MessageType;
  text?: string;
  cards?: Array<Record<string, unknown>>;
  quickReplies?: Array<{ label: string; payload: string }>;
}

const MAX_TEXT_LENGTH = 4096;
const ALLOWED_ORIGINS = new Set(['genesys.cloud', 'example.com']);

function validateSecurityPipelines(payload: MessagePayload, requestOrigin: string): void {
  if (!ALLOWED_ORIGINS.has(new URL(requestOrigin).hostname)) {
    throw new Error(`CORS verification failed: origin ${requestOrigin} is not in the allowed list`);
  }

  if (payload.type === 'text' && payload.text) {
    const sanitized = payload.text.replace(/<script[\s\S]*?>[\s\S]*?<\/script>|<\/?[^>]+>/gi, '');
    if (sanitized.length !== payload.text.length) {
      throw new Error('CSP violation: payload contains disallowed HTML or script directives');
    }
    if (payload.text.length > MAX_TEXT_LENGTH) {
      throw new Error(`Schema validation failed: text exceeds maximum size limit of ${MAX_TEXT_LENGTH} characters`);
    }
  }

  if (payload.type === 'card' && payload.cards) {
    payload.cards.forEach((card, index) => {
      if (!card.title || typeof card.title !== 'string') {
        throw new Error(`Card directive flag violation: card at index ${index} must contain a string title`);
      }
    });
  }
}

Step 2: Atomic Transmission with Retry and Latency Tracking

The Conversations API processes messages atomically. A single POST request creates the message record and triggers downstream routing. The following function implements exponential backoff for 429 responses, tracks transmission latency, and returns structured delivery metrics.

interface TransmissionMetrics {
  latencyMs: number;
  statusCode: number;
  requestId: string;
  success: boolean;
}

async function sendMessageAtomic(
  authManager: GenesysAuthManager,
  conversationId: string,
  payload: MessagePayload,
  maxRetries: number = 3
): Promise<TransmissionMetrics> {
  const token = await authManager.getAccessToken();
  const url = `${authManager.orgUrl}/api/v2/conversations/${conversationId}/messages`;
  let attempt = 0;
  const startTime = performance.now();

  while (attempt <= maxRetries) {
    const response = await fetch(url, {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${token}`,
        'Content-Type': 'application/json',
        'Accept': 'application/json',
        'X-Genesys-Request-Id': crypto.randomUUID()
      },
      body: JSON.stringify(payload)
    });

    const latency = performance.now() - startTime;

    if (response.ok) {
      return {
        latencyMs: Math.round(latency),
        statusCode: response.status,
        requestId: response.headers.get('x-genesys-request-id') || 'unknown',
        success: true
      };
    }

    if (response.status === 429 && attempt < maxRetries) {
      const retryAfter = parseInt(response.headers.get('retry-after') || '2', 10);
      await new Promise(resolve => setTimeout(resolve, retryAfter * 1000 * (attempt + 1)));
      attempt++;
      continue;
    }

    const errorBody = await response.text();
    throw new Error(`Transmission failed (${response.status}): ${errorBody}`);
  }

  throw new Error('Maximum retry attempts exceeded');
}

Step 3: Audit Logging and CRM Webhook Synchronization

Compliance requires immutable audit trails. The following function generates a SHA-256 hash of the exact payload transmitted, records delivery metrics, and triggers an external CRM synchronization webhook. Read receipt tracking is enabled by registering a Genesys Cloud webhook for conversation:participated:read events.

interface AuditRecord {
  timestamp: string;
  conversationId: string;
  payloadHash: string;
  metrics: TransmissionMetrics;
  crmSyncUrl: string;
}

async function generateAuditLog(
  conversationId: string,
  payload: MessagePayload,
  metrics: TransmissionMetrics,
  crmWebhookUrl: string
): Promise<AuditRecord> {
  const payloadString = JSON.stringify(payload, null, 2);
  const hashBuffer = await crypto.subtle.digest('SHA-256', new TextEncoder().encode(payloadString));
  const payloadHash = Array.from(new Uint8Array(hashBuffer)).map(b => b.toString(16).padStart(2, '0')).join('');

  const syncPayload = {
    conversationId,
    messageId: metrics.requestId,
    deliveryLatencyMs: metrics.latencyMs,
    status: metrics.success ? 'delivered' : 'failed',
    timestamp: new Date().toISOString()
  };

  await fetch(crmWebhookUrl, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(syncPayload)
  });

  return {
    timestamp: new Date().toISOString(),
    conversationId,
    payloadHash,
    metrics,
    crmSyncUrl
  };
}

Complete Working Example

The following module combines authentication, validation, transmission, and audit logging into a single reusable class. Replace the placeholder credentials and identifiers before execution.

import * as crypto from 'crypto';

type MessageType = 'text' | 'card' | 'quickReply';

interface MessagePayload {
  to: { id: string };
  from: { id: string };
  type: MessageType;
  text?: string;
  cards?: Array<Record<string, unknown>>;
  quickReplies?: Array<{ label: string; payload: string }>;
}

interface TransmissionMetrics {
  latencyMs: number;
  statusCode: number;
  requestId: string;
  success: boolean;
}

interface AuditRecord {
  timestamp: string;
  conversationId: string;
  payloadHash: string;
  metrics: TransmissionMetrics;
  crmSyncUrl: string;
}

const MAX_TEXT_LENGTH = 4096;
const ALLOWED_ORIGINS = new Set(['genesys.cloud', 'example.com']);

class GenesysAuthManager {
  private cache: { accessToken: string; expiresAt: number } | null = null;

  constructor(private readonly orgUrl: string, private readonly clientId: string, private readonly clientSecret: string) {}

  async getAccessToken(): Promise<string> {
    const now = Date.now();
    if (this.cache && now < this.cache.expiresAt - 10_000) {
      return this.cache.accessToken;
    }

    const tokenUrl = `${this.orgUrl}/oauth/token`;
    const body = new URLSearchParams({
      grant_type: 'client_credentials',
      client_id: this.clientId,
      client_secret: this.clientSecret,
      scope: 'conversation:write'
    });

    const response = await fetch(tokenUrl, {
      method: 'POST',
      headers: { 'Content-Type': 'application/x-www-form-urlencoded', 'Accept': 'application/json' },
      body: body.toString()
    });

    if (!response.ok) throw new Error(`OAuth token acquisition failed (${response.status})`);
    const data = await response.json() as { access_token: string; expires_in: number };
    this.cache = { accessToken: data.access_token, expiresAt: now + (data.expires_in * 1000) };
    return this.cache.accessToken;
  }
}

export class WebMessagingBotSender {
  private readonly authManager: GenesysAuthManager;

  constructor(orgUrl: string, clientId: string, clientSecret: string) {
    this.authManager = new GenesysAuthManager(orgUrl, clientId, clientSecret);
  }

  private validateSecurityPipelines(payload: MessagePayload, requestOrigin: string): void {
    if (!ALLOWED_ORIGINS.has(new URL(requestOrigin).hostname)) {
      throw new Error(`CORS verification failed: origin ${requestOrigin} is not allowed`);
    }

    if (payload.type === 'text' && payload.text) {
      const sanitized = payload.text.replace(/<script[\s\S]*?>[\s\S]*?<\/script>|<\/?[^>]+>/gi, '');
      if (sanitized.length !== payload.text.length) {
        throw new Error('CSP violation: payload contains disallowed HTML or script directives');
      }
      if (payload.text.length > MAX_TEXT_LENGTH) {
        throw new Error(`Schema validation failed: text exceeds maximum size limit of ${MAX_TEXT_LENGTH}`);
      }
    }

    if (payload.type === 'card' && payload.cards) {
      payload.cards.forEach((card, index) => {
        if (!card.title || typeof card.title !== 'string') {
          throw new Error(`Card directive flag violation: card at index ${index} requires a string title`);
        }
      });
    }
  }

  async send(
    conversationId: string,
    payload: MessagePayload,
    requestOrigin: string,
    crmWebhookUrl: string,
    maxRetries: number = 3
  ): Promise<AuditRecord> {
    this.validateSecurityPipelines(payload, requestOrigin);

    const token = await this.authManager.getAccessToken();
    const url = `${this.authManager.orgUrl}/api/v2/conversations/${conversationId}/messages`;
    let attempt = 0;
    const startTime = performance.now();
    let metrics: TransmissionMetrics | null = null;

    while (attempt <= maxRetries) {
      const response = await fetch(url, {
        method: 'POST',
        headers: {
          'Authorization': `Bearer ${token}`,
          'Content-Type': 'application/json',
          'Accept': 'application/json',
          'X-Genesys-Request-Id': crypto.randomUUID()
        },
        body: JSON.stringify(payload)
      });

      const latency = performance.now() - startTime;

      if (response.ok) {
        metrics = {
          latencyMs: Math.round(latency),
          statusCode: response.status,
          requestId: response.headers.get('x-genesys-request-id') || 'unknown',
          success: true
        };
        break;
      }

      if (response.status === 429 && attempt < maxRetries) {
        const retryAfter = parseInt(response.headers.get('retry-after') || '2', 10);
        await new Promise(resolve => setTimeout(resolve, retryAfter * 1000 * (attempt + 1)));
        attempt++;
        continue;
      }

      const errorBody = await response.text();
      throw new Error(`Transmission failed (${response.status}): ${errorBody}`);
    }

    if (!metrics) throw new Error('Maximum retry attempts exceeded');

    const payloadString = JSON.stringify(payload, null, 2);
    const hashBuffer = await crypto.subtle.digest('SHA-256', new TextEncoder().encode(payloadString));
    const payloadHash = Array.from(new Uint8Array(hashBuffer)).map(b => b.toString(16).padStart(2, '0')).join('');

    const syncPayload = {
      conversationId,
      messageId: metrics.requestId,
      deliveryLatencyMs: metrics.latencyMs,
      status: metrics.success ? 'delivered' : 'failed',
      timestamp: new Date().toISOString()
    };

    await fetch(crmWebhookUrl, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(syncPayload)
    });

    return {
      timestamp: new Date().toISOString(),
      conversationId,
      payloadHash,
      metrics,
      crmSyncUrl
    };
  }
}

// Execution block
(async () => {
  const sender = new WebMessagingBotSender(
    'https://myorg.mygen.com',
    'YOUR_CLIENT_ID',
    'YOUR_CLIENT_SECRET'
  );

  const payload: MessagePayload = {
    to: { id: 'customer-participant-id-123' },
    from: { id: 'bot-participant-id-456' },
    type: 'text',
    text: 'Thank you for contacting support. An agent will review your request shortly.'
  };

  try {
    const audit = await sender.send(
      'conversation-id-789',
      payload,
      'https://genesys.cloud',
      'https://your-crm.example.com/webhooks/genesys-sync'
    );
    console.log('Audit Record:', JSON.stringify(audit, null, 2));
  } catch (error) {
    console.error('Bot sender failed:', error);
  }
})();

Common Errors & Debugging

Error: 401 Unauthorized

• Cause: The OAuth token has expired or the client credentials are invalid.
• Fix: Verify the client_id and client_secret match a configured OAuth client in Genesys Cloud. Ensure the scope includes conversation:write. The GenesysAuthManager automatically refreshes tokens, but a 401 after refresh indicates credential misconfiguration.

Error: 400 Bad Request

• Cause: The payload violates Genesys Cloud schema constraints. Common triggers include missing to or from participant IDs, invalid type values, or text exceeding 4096 characters.
• Fix: Validate the MessagePayload structure before transmission. Use the validateSecurityPipelines function to catch size violations and malformed card directives. Inspect the x-genesys-request-id in the response headers and cross-reference it with the Genesys Cloud API error details.

Error: 429 Too Many Requests

• Cause: The Conversations API rate limit has been reached. Genesys Cloud enforces per-organization and per-endpoint throttling.
• Fix: The implementation includes exponential backoff with retry-after header parsing. If the error persists, reduce message throughput or implement a queueing mechanism. Monitor the Retry-After header value, which indicates the exact wait duration in seconds.

Error: 500 Internal Server Error

• Cause: A transient failure in the Genesys Cloud messaging pipeline or participant state mismatch.
• Fix: Verify that the conversationId exists and is in an active state. Check that both to and from participant IDs belong to the same conversation. Implement a circuit breaker pattern for repeated 5xx responses to prevent cascading failures.

Official References

• Genesys Cloud Conversations API Documentation
• POST /api/v2/conversations/{conversationId}/messages Endpoint Reference
• OAuth 2.0 Client Credentials Flow Guide
• Web Messaging Channel Constraints and Payload Limits