Creating Genesys Cloud Web Messaging Guest Sessions via Guest API with TypeScript

What You Will Build

A TypeScript module that programmatically creates Genesys Cloud guest sessions, validates JWT tokens, establishes WebSocket connections, persists state, syncs external profiles, and exposes a manager interface for widget integration.
This tutorial uses the Genesys Cloud CX Guest API (/api/v2/guests) and the native WebSocket messaging endpoint.
The implementation covers TypeScript 4.5+ with native fetch and WebSocket APIs.

Prerequisites

• OAuth 2.0 confidential client with guest:create, guest:read, webchat:send, and user:read scopes
• Genesys Cloud organization subdomain (for example, acme.mypurecloud.com)
• Node.js 18+ or a modern browser environment with ES modules support
• No external runtime dependencies required beyond TypeScript compiler

Authentication Setup

Genesys Cloud requires a bearer token for all Guest API calls. You must exchange client credentials for an access token before creating guests. The following function implements token acquisition with retry logic for rate limits.

interface TokenResponse {
  access_token: string;
  token_type: string;
  expires_in: number;
  scope: string;
}

async function acquireAdminToken(
  org: string,
  clientId: string,
  clientSecret: string
): Promise<string> {
  const tokenUrl = `https://${org}.mypurecloud.com/oauth/token`;
  const body = new URLSearchParams({
    grant_type: "client_credentials",
    client_id: clientId,
    client_secret: clientSecret,
    scope: "guest:create guest:read webchat:send"
  });

  const maxRetries = 3;
  let attempt = 0;

  while (attempt < maxRetries) {
    try {
      const response = await fetch(tokenUrl, {
        method: "POST",
        headers: { "Content-Type": "application/x-www-form-urlencoded" },
        body: body.toString()
      });

      if (response.status === 429) {
        const retryAfter = parseInt(response.headers.get("Retry-After") || "2", 10);
        await new Promise(resolve => setTimeout(resolve, retryAfter * 1000));
        attempt++;
        continue;
      }

      if (!response.ok) {
        throw new Error(`Token acquisition failed: ${response.status} ${response.statusText}`);
      }

      const data: TokenResponse = await response.json();
      return data.access_token;
    } catch (error) {
      if (attempt === maxRetries - 1) throw error;
      attempt++;
      await new Promise(resolve => setTimeout(resolve, 1000 * Math.pow(2, attempt)));
    }
  }
  throw new Error("Token acquisition exhausted retries");
}

Implementation

Step 1: Construct Session Initiation Payloads with Custom Attributes & Routing Hints

The Guest API accepts a JSON payload containing routing hints and custom attributes. These values determine queue placement and downstream workflow logic. The required OAuth scope is guest:create.

interface GuestInitPayload {
  name: string;
  attributes: Record<string, unknown>;
  routing: {
    queue: { id: string };
    skill: { id: string };
    language: string;
  };
}

async function createGuestSession(
  org: string,
  adminToken: string,
  payload: GuestInitPayload
): Promise<{ guestId: string; guestToken: string; sessionId: string }> {
  const url = `https://${org}.mypurecloud.com/api/v2/guests`;

  const response = await fetch(url, {
    method: "POST",
    headers: {
      "Authorization": `Bearer ${adminToken}`,
      "Content-Type": "application/json",
      "Accept": "application/json"
    },
    body: JSON.stringify(payload)
  });

  if (response.status === 401 || response.status === 403) {
    throw new Error(`Authentication or authorization failed: ${response.status}`);
  }
  if (response.status === 429) {
    const retryAfter = parseInt(response.headers.get("Retry-After") || "2", 10);
    await new Promise(resolve => setTimeout(resolve, retryAfter * 1000));
    return createGuestSession(org, adminToken, payload);
  }
  if (!response.ok) {
    const errorBody = await response.text();
    throw new Error(`Guest creation failed: ${response.status} - ${errorBody}`);
  }

  const data = await response.json();
  // Realistic response structure
  // {
  //   "id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  //   "guestToken": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  //   "sessions": [{ "id": "session-uuid-1234" }],
  //   "attributes": { ... }
  // }

  return {
    guestId: data.id,
    guestToken: data.guestToken,
    sessionId: data.sessions[0].id
  };
}

Step 2: Validate Guest Identity Claims Against JWT Token Structures

The guestToken returned by the API is a JWT containing expiration and identity claims. Client-side validation prevents stale token usage and ensures routing hints match the expected schema. This function decodes the payload, verifies the expiration timestamp, and checks required claims.

interface GuestClaims {
  sub: string;
  exp: number;
  iat: number;
  routing_hints: Record<string, string>;
  attributes: Record<string, unknown>;
}

function validateGuestToken(token: string): GuestClaims {
  if (!token || typeof token !== "string") {
    throw new Error("Invalid guest token format");
  }

  const parts = token.split(".");
  if (parts.length !== 3) {
    throw new Error("Malformed JWT structure");
  }

  const payloadBase64 = parts[1];
  const padding = Array(4 - (payloadBase64.length % 4)).join("=");
  const payloadJson = atob(payloadBase64 + padding);
  const claims: GuestClaims = JSON.parse(payloadJson);

  const now = Math.floor(Date.now() / 1000);
  if (!claims.exp || claims.exp < now) {
    throw new Error("Guest token has expired");
  }

  if (!claims.routing_hints || Object.keys(claims.routing_hints).length === 0) {
    throw new Error("Guest token missing routing hints");
  }

  return claims;
}

Step 3: Handle Asynchronous Session Establishment via WebSocket Handshake Protocols

Genesys Cloud web messaging routes real-time traffic through a WebSocket endpoint. The connection requires a handshake message containing the guest token immediately after the socket opens. The required scope for the WebSocket connection is webchat:send.

interface WsMessage {
  type: string;
  token?: string;
  payload?: Record<string, unknown>;
}

function establishWebSocket(
  org: string,
  guestId: string,
  sessionId: string,
  guestToken: string
): WebSocket {
  const wsUrl = `wss://${org}.mypurecloud.com/api/v2/guests/${guestId}/sessions/${sessionId}/ws`;
  const socket = new WebSocket(wsUrl);

  socket.onopen = () => {
    const handshake: WsMessage = {
      type: "handshake",
      token: guestToken
    };
    socket.send(JSON.stringify(handshake));
  };

  socket.onmessage = (event: MessageEvent) => {
    try {
      const message: WsMessage = JSON.parse(event.data as string);
      console.log("WebSocket message received:", message);
    } catch (error) {
      console.error("Failed to parse WebSocket message:", error);
    }
  };

  socket.onerror = (error: Event) => {
    console.error("WebSocket connection error:", error);
  };

  socket.onclose = (event: CloseEvent) => {
    if (event.wasClean) {
      console.log("WebSocket closed cleanly", event.code, event.reason);
    } else {
      console.error("WebSocket connection dropped unexpectedly");
    }
  };

  return socket;
}

Step 4: Implement Session Persistence Logic Using Client-Side Storage with Automatic Refresh Mechanisms

Guest sessions must survive page reloads. This logic stores session metadata in localStorage, checks token expiration on load, and triggers a silent refresh when the TTL drops below a threshold.

interface PersistedSession {
  guestId: string;
  guestToken: string;
  sessionId: string;
  createdAt: number;
  expiresAt: number;
}

const STORAGE_KEY = "genesys_guest_session";
const REFRESH_THRESHOLD_MS = 5 * 60 * 1000; // 5 minutes before expiration

function loadSession(): PersistedSession | null {
  const raw = localStorage.getItem(STORAGE_KEY);
  if (!raw) return null;

  try {
    const session: PersistedSession = JSON.parse(raw);
    const now = Date.now();
    if (session.expiresAt - now < REFRESH_THRESHOLD_MS) {
      console.warn("Session approaching expiration, refresh required");
      return null;
    }
    return session;
  } catch {
    localStorage.removeItem(STORAGE_KEY);
    return null;
  }
}

function persistSession(session: PersistedSession): void {
  localStorage.setItem(STORAGE_KEY, JSON.stringify(session));
}

function clearSession(): void {
  localStorage.removeItem(STORAGE_KEY);
}

Step 5: Synchronize Guest Profiles with External Identity Providers via OAuth2 Delegation

When a guest authenticates with an external provider, you exchange the delegation token for a Genesys access token and update the guest profile. The PUT /api/v2/guests/{guestId} endpoint merges attributes. Required scope: guest:read and user:read.

async function syncGuestProfile(
  org: string,
  adminToken: string,
  guestId: string,
  externalProviderId: string,
  externalEmail: string
): Promise<void> {
  const url = `https://${org}.mypurecloud.com/api/v2/guests/${guestId}`;

  const body = {
    attributes: {
      external_provider_id: externalProviderId,
      external_email: externalEmail,
      synced_at: new Date().toISOString(),
      delegation_verified: true
    }
  };

  const response = await fetch(url, {
    method: "PUT",
    headers: {
      "Authorization": `Bearer ${adminToken}`,
      "Content-Type": "application/json"
    },
    body: JSON.stringify(body)
  });

  if (response.status === 404) {
    throw new Error("Guest not found. Session may have expired.");
  }
  if (response.status === 429) {
    const retryAfter = parseInt(response.headers.get("Retry-After") || "2", 10);
    await new Promise(resolve => setTimeout(resolve, retryAfter * 1000));
    return syncGuestProfile(org, adminToken, guestId, externalProviderId, externalEmail);
  }
  if (!response.ok) {
    const errorBody = await response.text();
    throw new Error(`Profile sync failed: ${response.status} - ${errorBody}`);
  }
}

Step 6: Track Session Duration Metrics for Engagement Analytics & Generate Guest Activity Logs

Accurate duration tracking requires recording the exact timestamp of session creation and calculating deltas on termination. Activity logs capture state transitions for security reviews.

interface ActivityLog {
  timestamp: string;
  event: string;
  details: Record<string, unknown>;
}

class SessionMetrics {
  private startTime: number = 0;
  private logs: ActivityLog[] = [];

  start(): void {
    this.startTime = Date.now();
    this.logEvent("session_started", { duration_ms: 0 });
  }

  logEvent(event: string, details: Record<string, unknown> = {}): void {
    this.logs.push({
      timestamp: new Date().toISOString(),
      event,
      details
    });
  }

  getDurationMs(): number {
    return Date.now() - this.startTime;
  }

  getFinalReport(): { duration_ms: number; logs: ActivityLog[] } {
    return {
      duration_ms: this.getDurationMs(),
      logs: this.logs
    };
  }
}

Complete Working Example

The following class combines all components into a single manager interface suitable for widget integration. It handles initialization, persistence, WebSocket lifecycle, and profile synchronization.

interface GuestManagerConfig {
  org: string;
  clientId: string;
  clientSecret: string;
  routingQueueId: string;
  routingSkillId: string;
  routingLanguage: string;
}

class GuestSessionManager {
  private config: GuestManagerConfig;
  private adminToken: string | null = null;
  private socket: WebSocket | null = null;
  private metrics: SessionMetrics = new SessionMetrics();
  private currentSession: PersistedSession | null = null;

  constructor(config: GuestManagerConfig) {
    this.config = config;
  }

  async initialize(): Promise<void> {
    const existing = loadSession();
    if (existing) {
      this.currentSession = existing;
      console.log("Resumed existing guest session");
      return;
    }

    this.adminToken = await acquireAdminToken(
      this.config.org,
      this.config.clientId,
      this.config.clientSecret
    );

    const payload: GuestInitPayload = {
      name: "Web Guest",
      attributes: {
        source: "custom_widget",
        locale: navigator.language,
        user_agent: navigator.userAgent
      },
      routing: {
        queue: { id: this.config.routingQueueId },
        skill: { id: this.config.routingSkillId },
        language: this.config.routingLanguage
      }
    };

    const created = await createGuestSession(this.config.org, this.adminToken, payload);

    try {
      const claims = validateGuestToken(created.guestToken);
      this.currentSession = {
        guestId: created.guestId,
        guestToken: created.guestToken,
        sessionId: created.sessionId,
        createdAt: Date.now(),
        expiresAt: claims.exp * 1000
      };
      persistSession(this.currentSession);
      this.metrics.start();
      console.log("New guest session created and persisted");
    } catch (error) {
      console.error("Token validation failed, discarding session:", error);
      clearSession();
      throw error;
    }
  }

  connectWebSocket(): void {
    if (!this.currentSession) throw new Error("No active session");
    if (this.socket && this.socket.readyState === WebSocket.OPEN) {
      console.log("WebSocket already connected");
      return;
    }

    this.socket = establishWebSocket(
      this.config.org,
      this.currentSession.guestId,
      this.currentSession.sessionId,
      this.currentSession.guestToken
    );

    this.socket.onmessage = (event: MessageEvent) => {
      const data = JSON.parse(event.data as string);
      this.metrics.logEvent("ws_message_received", { type: data.type });
    };

    this.socket.onclose = () => {
      this.metrics.logEvent("ws_disconnected", { duration_ms: this.metrics.getDurationMs() });
    };
  }

  async syncExternalProfile(providerId: string, email: string): Promise<void> {
    if (!this.adminToken || !this.currentSession) {
      throw new Error("Session not initialized or admin token unavailable");
    }
    await syncGuestProfile(
      this.config.org,
      this.adminToken,
      this.currentSession.guestId,
      providerId,
      email
    );
    this.metrics.logEvent("profile_synced", { provider_id: providerId });
  }

  terminate(): void {
    if (this.socket) {
      this.socket.close(1000, "Widget disconnect");
    }
    const report = this.metrics.getFinalReport();
    console.log("Session terminated. Metrics:", report);
    clearSession();
  }

  getMetrics(): { duration_ms: number; logs: ActivityLog[] } {
    return this.metrics.getFinalReport();
  }
}

Common Errors & Debugging

Error: 401 Unauthorized or 403 Forbidden

• Cause: The OAuth client lacks the required guest:create or webchat:send scope, or the token has expired.
• Fix: Verify the client credentials in the Genesys Cloud Admin console. Regenerate the token using the acquireAdminToken function. Ensure the scope string matches exactly.

Error: 429 Too Many Requests

• Cause: Exceeding the Guest API rate limit (typically 200 requests per minute per client).
• Fix: The provided code implements exponential backoff with Retry-After header parsing. For high-throughput widgets, implement a request queue with a token bucket algorithm.

Error: WebSocket 1006 Abnormal Closure

• Cause: The server rejected the handshake due to an invalid or expired guest token, or network interruption.
• Fix: Validate the JWT expiration before connecting. Reinitialize the session if the token age exceeds the exp claim. Check firewall rules blocking wss:// traffic on port 443.

Error: 400 Bad Request on Profile Sync

• Cause: The guest ID does not exist, or the payload exceeds attribute size limits (Genesys limits custom attributes to 10KB per guest).
• Fix: Verify the guest ID matches the active session. Trim non-essential attributes before sending the PUT request.

Official References

• Genesys Cloud Guest API Documentation
• Web Messaging WebSocket Protocol
• OAuth 2.0 Client Credentials Flow
• Guest Session Attributes & Routing Schema