Implementing a Python Script to Create Web Messaging Guest Sessions and Inject Bot Messages via the Guest API

What You Will Build

• A production-grade Python script that programmatically creates headless Web Messaging guest sessions and injects automated bot messages into the resulting conversation.
• This implementation uses the Genesys Cloud CX Web Messaging Guest API (/api/v2/external/webmessaging/guests and /api/v2/external/webmessaging/guests/{guestId}/messages).
• The code is written in Python 3.9+ using the httpx library for HTTP transport and explicit retry logic for rate-limit resilience.

Prerequisites

• OAuth Client Type: Confidential Client (Client Credentials Grant). The client must be registered in the Genesys Cloud Admin Console under Admin > Security > OAuth Clients.
• Required OAuth Scopes: webmessaging:guest:write, webmessaging:guest:read
• SDK/API Version: Genesys Cloud REST API v2 (Web Messaging Guest endpoints)
• Runtime: Python 3.9 or higher
• External Dependencies: httpx, pydantic, tenacity (install via pip install httpx pydantic tenacity)

Authentication Setup

Genesys Cloud enforces OAuth 2.0 for all API access. The Client Credentials flow is the standard mechanism for server-to-server automation because it does not require user interaction and returns a machine-scoped access token. The token expires after sixty minutes, so production systems must implement token caching and automatic refresh logic.

The following function handles token acquisition, stores the expiry timestamp, and raises a structured exception when the endpoint returns a non-success status.

import httpx
import base64
import logging
from typing import Optional
from datetime import datetime, timezone

logger = logging.getLogger(__name__)

class OAuthTokenManager:
    def __init__(self, client_id: str, client_secret: str, base_url: str = "https://api.mypurecloud.com"):
        self.client_id = client_id
        self.client_secret = client_secret
        self.base_url = base_url.rstrip("/")
        self.access_token: Optional[str] = None
        self.expires_at: Optional[datetime] = None
        self.token_url = f"{self.base_url}/oauth/token"

    def _get_auth_header(self) -> str:
        credentials = f"{self.client_id}:{self.client_secret}"
        encoded = base64.b64encode(credentials.encode()).decode()
        return f"Basic {encoded}"

    def fetch_token(self, scopes: list[str]) -> str:
        if self.access_token and self.expires_at and datetime.now(timezone.utc) < self.expires_at:
            logger.debug("Returning cached access token.")
            return self.access_token

        scope_str = " ".join(scopes)
        payload = {
            "grant_type": "client_credentials",
            "scope": scope_str
        }
        headers = {
            "Content-Type": "application/x-www-form-urlencoded",
            "Authorization": self._get_auth_header()
        }

        logger.info("Requesting new OAuth token for scopes: %s", scope_str)
        response = httpx.post(self.token_url, data=payload, headers=headers, timeout=15.0)
        response.raise_for_status()

        token_data = response.json()
        self.access_token = token_data["access_token"]
        self.expires_at = datetime.now(timezone.utc) + datetime.timedelta(seconds=token_data["expires_in"] - 30)
        
        logger.info("OAuth token acquired successfully. Expires at %s", self.expires_at)
        return self.access_token

The - 30 second buffer on expires_at prevents edge-case expiration during active API calls. The token manager reuses cached tokens until the buffer window closes, reducing unnecessary network overhead.

Implementation

Step 1: Create a Web Messaging Guest Session

Creating a guest session via the API bypasses the standard web widget UI. This design allows backend systems to simulate user traffic, trigger IVR routing rules, or feed data into conversational AI flows without browser automation. The API expects a JSON payload containing at minimum a name and optionally routing directives.

The endpoint returns a guestId and a conversationId. You must preserve both identifiers. The guestId routes subsequent messages to the correct session, while the conversationId links the message to the Genesys Cloud conversation graph for analytics and transcription.

import httpx
import json
import logging
from typing import Dict, Any

logger = logging.getLogger(__name__)

class WebMessagingGuestClient:
    def __init__(self, base_url: str, token_manager: OAuthTokenManager):
        self.base_url = base_url.rstrip("/")
        self.token_manager = token_manager
        self.client = httpx.Client(base_url=self.base_url, timeout=30.0)

    def create_guest_session(self, guest_data: Dict[str, Any]) -> Dict[str, Any]:
        token = self.token_manager.fetch_token(["webmessaging:guest:write"])
        headers = {
            "Authorization": f"Bearer {token}",
            "Content-Type": "application/json",
            "Accept": "application/json"
        }
        endpoint = "/api/v2/external/webmessaging/guests"
        url = f"{self.base_url}{endpoint}"

        logger.info("Creating guest session with payload: %s", json.dumps(guest_data))
        response = self.client.post(url, json=guest_data, headers=headers)
        
        if response.status_code == 429:
            raise httpx.HTTPStatusError("Rate limit exceeded. Implement exponential backoff.", request=response.request, response=response)
        response.raise_for_status()

        guest_response = response.json()
        logger.info("Guest session created. ID: %s, Conversation ID: %s", 
                    guest_response.get("id"), guest_response.get("conversationId"))
        return guest_response

Required OAuth Scope: webmessaging:guest:write

Expected Response Body:

{
  "id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "conversationId": "98765432-10ab-cdef-1234-567890abcdef",
  "name": "Automated Test Guest",
  "email": "test.guest@example.com",
  "languageCode": "en-US",
  "routingData": {
    "queueId": "queue-12345678-90ab-cdef-1234-567890abcdef"
  },
  "createdAt": "2024-05-15T10:30:00.000Z"
}

The API rejects payloads missing a name field. If you provide routingData.queueId, the system immediately places the guest in the specified queue. Omitting routing data leaves the guest in an unassigned state until a message triggers routing evaluation.

Step 2: Inject Bot Messages into the Guest Session

Message injection uses a separate endpoint scoped to the guest identifier. The API distinguishes message authors using the author.type field. Valid values are user, agent, bot, and system. Injecting a bot message triggers conversational AI handoffs, updates transcript state, and can fire webhook events configured in the Web Messaging profile.

You must pass the conversationId returned in Step 1. The API validates this identifier to prevent cross-session message pollution.

import httpx
import json
import logging
from typing import Dict, Any

logger = logging.getLogger(__name__)

class WebMessagingGuestClient:
    # ... (previous init and create_guest_session methods remain)

    def inject_bot_message(self, guest_id: str, conversation_id: str, message_text: str) -> Dict[str, Any]:
        token = self.token_manager.fetch_token(["webmessaging:guest:write"])
        headers = {
            "Authorization": f"Bearer {token}",
            "Content-Type": "application/json",
            "Accept": "application/json"
        }
        endpoint = f"/api/v2/external/webmessaging/guests/{guest_id}/messages"
        url = f"{self.base_url}{endpoint}"

        payload = {
            "type": "text",
            "text": message_text,
            "conversationId": conversation_id,
            "author": {
                "type": "bot"
            }
        }

        logger.info("Injecting bot message to guest %s", guest_id)
        response = self.client.post(url, json=payload, headers=headers)

        if response.status_code == 429:
            raise httpx.HTTPStatusError("Rate limit exceeded on message injection.", request=response.request, response=response)
        response.raise_for_status()

        message_response = response.json()
        logger.info("Bot message injected successfully. Message ID: %s", message_response.get("id"))
        return message_response

Required OAuth Scope: webmessaging:guest:write

Expected Response Body:

{
  "id": "msg-11223344-5566-7788-99aa-bbccddeeff00",
  "type": "text",
  "text": "Hello from the automated bot system.",
  "author": {
    "type": "bot"
  },
  "conversationId": "98765432-10ab-cdef-1234-567890abcdef",
  "createdAt": "2024-05-15T10:30:05.000Z"
}

The API enforces strict ordering. You cannot inject a message before the guest session reaches an active state. If the guest is still routing, the API returns a 409 Conflict with a message indicating the session is not ready. Implementing a short polling loop or waiting for the initial user message is standard practice.

Step 3: Implement Rate Limit Resilience and Execution Flow

Genesys Cloud applies per-tenant and per-endpoint rate limits. Web Messaging endpoints typically enforce a limit of one hundred requests per minute per OAuth client. Exceeding this threshold returns a 429 Too Many Requests response with a Retry-After header. Production scripts must parse this header and back off accordingly.

The following execution wrapper combines token management, guest creation, and message injection with automatic retry logic for transient failures.

import time
import logging
from typing import Dict, Any
from tenacity import retry, stop_after_attempt, wait_exponential, retry_if_exception_type

logger = logging.getLogger(__name__)

@retry(
    stop=stop_after_attempt(4),
    wait=wait_exponential(multiplier=1, min=2, max=10),
    retry=retry_if_exception_type(httpx.HTTPStatusError),
    reraise=True
)
def execute_guest_workflow(token_manager: OAuthTokenManager, base_url: str, queue_id: str) -> Dict[str, Any]:
    client = WebMessagingGuestClient(base_url=base_url, token_manager=token_manager)
    
    guest_payload = {
        "name": "API Automated Guest",
        "email": "automation@example.com",
        "languageCode": "en-US",
        "routingData": {
            "queueId": queue_id
        }
    }

    try:
        guest = client.create_guest_session(guest_payload)
        guest_id = guest["id"]
        conversation_id = guest["conversationId"]
    except httpx.HTTPStatusError as e:
        logger.error("Failed to create guest session: %s", e.response.text)
        raise

    # Allow routing engine to initialize the conversation
    time.sleep(2)

    try:
        message = client.inject_bot_message(
            guest_id=guest_id,
            conversation_id=conversation_id,
            message_text="This is an automated system message for testing purposes."
        )
    except httpx.HTTPStatusError as e:
        logger.error("Failed to inject bot message: %s", e.response.text)
        raise

    return {
        "guest_id": guest_id,
        "conversation_id": conversation_id,
        "message_id": message["id"]
    }

The tenacity decorator handles 429 responses by catching httpx.HTTPStatusError. The exponential backoff starts at two seconds and caps at ten seconds across four attempts. This pattern prevents cascading failures during high-throughput scenarios. The time.sleep(2) call accommodates the asynchronous routing engine, which requires approximately one to three seconds to assign a conversation to a queue or virtual agent.

Complete Working Example

The following script integrates all components into a single executable module. Replace the placeholder credentials and queue identifier before running.

#!/usr/bin/env python3
import os
import sys
import logging
import httpx

from oauth_manager import OAuthTokenManager
from guest_client import WebMessagingGuestClient
from workflow import execute_guest_workflow

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
    handlers=[logging.StreamHandler(sys.stdout)]
)
logger = logging.getLogger(__name__)

def main():
    client_id = os.getenv("GENESYS_CLIENT_ID")
    client_secret = os.getenv("GENESYS_CLIENT_SECRET")
    base_url = os.getenv("GENESYS_BASE_URL", "https://api.mypurecloud.com")
    target_queue_id = os.getenv("GENESYS_TARGET_QUEUE_ID")

    if not all([client_id, client_secret, target_queue_id]):
        logger.error("Missing required environment variables: GENESYS_CLIENT_ID, GENESYS_CLIENT_SECRET, GENESYS_TARGET_QUEUE_ID")
        sys.exit(1)

    token_manager = OAuthTokenManager(client_id=client_id, client_secret=client_secret, base_url=base_url)
    
    try:
        result = execute_guest_workflow(
            token_manager=token_manager,
            base_url=base_url,
            queue_id=target_queue_id
        )
        logger.info("Workflow completed successfully.")
        logger.info("Guest ID: %s", result["guest_id"])
        logger.info("Conversation ID: %s", result["conversation_id"])
        logger.info("Message ID: %s", result["message_id"])
    except httpx.HTTPStatusError as e:
        logger.error("HTTP Error %s: %s", e.response.status_code, e.response.text)
        sys.exit(e.response.status_code)
    except Exception as e:
        logger.error("Unexpected error: %s", str(e))
        sys.exit(1)

if __name__ == "__main__":
    main()

Run the script with environment variables set:

export GENESYS_CLIENT_ID="your-client-id"
export GENESYS_CLIENT_SECRET="your-client-secret"
export GENESYS_TARGET_QUEUE_ID="your-queue-id"
python3 run_guest_workflow.py

Common Errors & Debugging

Error: 401 Unauthorized

• Cause: The OAuth token is expired, malformed, or missing from the Authorization header. The client credentials may also lack the required scopes.
• Fix: Verify the GENESYS_CLIENT_ID and GENESYS_CLIENT_SECRET match the registered OAuth client. Ensure the token manager refreshes the token before each request. Check that webmessaging:guest:write is attached to the OAuth client in the Admin Console.
• Code Fix: The OAuthTokenManager class automatically refreshes tokens when datetime.now(timezone.utc) >= self.expires_at. If you receive a 401 after a refresh, validate the base URL matches your Genesys Cloud region (e.g., api.mypurecloud.com for US, api.au.pure.cloud for Australia).

Error: 403 Forbidden

• Cause: The OAuth client has the correct token format but lacks the webmessaging:guest:write scope, or the tenant has disabled programmatic guest creation.
• Fix: Navigate to Admin > Security > OAuth Clients, select your client, and verify the scope list includes webmessaging:guest:write and webmessaging:guest:read. If the tenant restricts guest API access, request an exception from your Genesys Cloud administrator.
• Code Fix: Update the fetch_token call to explicitly request the correct scopes. The script already passes ["webmessaging:guest:write"] during creation and message injection.

Error: 429 Too Many Requests

• Cause: The client exceeded the per-minute rate limit for the Web Messaging Guest endpoints. Genesys Cloud returns a Retry-After header indicating the wait time in seconds.
• Fix: Implement exponential backoff. The execute_guest_workflow function uses the tenacity library to automatically retry failed requests with increasing delays. Do not bypass rate limits by spawning concurrent threads without a token bucket algorithm.
• Code Fix: The @retry decorator in the workflow handles 429s. If you require higher throughput, register multiple OAuth clients and distribute requests across them using a round-robin proxy.

Error: 409 Conflict

• Cause: Attempting to inject a message before the guest session reaches an active state, or providing a mismatched conversationId.
• Fix: Wait two to three seconds after guest creation before sending the first message. Verify that the conversationId passed to inject_bot_message exactly matches the conversationId returned during guest creation.
• Code Fix: The time.sleep(2) call in the workflow provides the necessary buffer. If you encounter persistent 409s, poll the guest status endpoint (GET /api/v2/external/webmessaging/guests/{guestId}) and wait for status to equal ACTIVE.

Official References

• Genesys Cloud Web Messaging Guest API Documentation
• Genesys Cloud OAuth Client Credentials Flow
• Genesys Cloud Python SDK Reference
• HTTP 429 Rate Limiting Guidelines