Handle File Attachments in Genesys Cloud Web Messaging via the API

What You Will Build

• Build a Python backend service that accepts file uploads from a Web Messaging session and stores them securely while generating the metadata required to inject the file into the conversation.
• Use the Genesys Cloud CX PureCloudPlatformClientV2 SDK to handle the multipart form-data upload and retrieve the resulting file reference.
• Implement strict validation for MIME types and file sizes before transmitting data to Genesys Cloud, ensuring compliance with platform limits.

Prerequisites

• OAuth Client Type: Service Account (Client Credentials Grant) or JWT (User Impersonation). For this tutorial, we use Client Credentials for a background service.
• Required Scopes:
  • analytics:export:read (if you need to audit uploads later)
  • conversation:webchat:write (to update the conversation with the file)
  • filestorage:upload (critical for the upload endpoint)
  • filestorage:read (to verify the upload)
• SDK Version: genesys-cloud Python SDK v1.0.0+ (ensure you are using the latest stable release).
• Language/Runtime: Python 3.9+.
• External Dependencies:
  • genesys-cloud: pip install genesys-cloud
  • python-magic: pip install python-magic (for robust MIME type detection based on file content, not just extension).
  • requests: Included in SDK dependencies, but useful for raw debugging.

Authentication Setup

Genesys Cloud requires an OAuth access token for all API calls. The SDK handles the token acquisition and refresh automatically when initialized correctly. We will create a reusable client instance.

import os
from genesyscloud.platform.client.configuration import Configuration
from genesyscloud.platform.client.api_client import ApiClient
from genesyscloud.platform.client.rest import ApiException

def create_genesys_client() -> ApiClient:
    """
    Initializes and returns a configured Genesys Cloud API Client.
    Uses environment variables for security.
    """
    # Load credentials from environment variables
    client_id = os.getenv("GENESYS_CLIENT_ID")
    client_secret = os.getenv("GENESYS_CLIENT_SECRET")
    base_url = os.getenv("GENESYS_BASE_URL", "https://api.us.genesyscloud.com")

    if not client_id or not client_secret:
        raise ValueError("GENESYS_CLIENT_ID and GENESYS_CLIENT_SECRET must be set in environment.")

    # Create configuration object
    config = Configuration(
        access_token_client_id=client_id,
        access_token_client_secret=client_secret,
        base_url=base_url,
        oauth_client_id=client_id,
        oauth_client_secret=client_secret
    )

    # Initialize the API Client
    # The SDK will automatically fetch the access token on the first API call
    api_client = ApiClient(configuration=config)
    return api_client

Note on Scopes: When creating your OAuth Client in the Genesys Admin Console, ensure the filestorage:upload scope is granted. Without this, the upload API will return a 403 Forbidden error, regardless of how correct the code is.

Implementation

Step 1: Validate File Content and Size

Before sending data to Genesys Cloud, you must validate the file. Genesys Cloud has strict limits:

• Maximum File Size: 10 MB (10,485,760 bytes) for Web Messaging attachments.
• Accepted MIME Types: The platform supports a specific whitelist. Common types include image/png, image/jpeg, application/pdf, text/plain, and several others. Sending an unsupported type results in a 400 Bad Request.

We use python-magic to detect the actual MIME type from the file header, preventing users from renaming a .exe file to .jpg to bypass security.

import magic
import os

# Define allowed MIME types for Web Messaging
ALLOWED_MIME_TYPES = {
    'image/png',
    'image/jpeg',
    'image/gif',
    'application/pdf',
    'text/plain',
    'text/csv',
    'application/msword',
    'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
    'application/zip'
}

MAX_FILE_SIZE_BYTES = 10 * 1024 * 1024  # 10 MB

def validate_file(file_path: str) -> tuple[str, int]:
    """
    Validates a file for size and MIME type.
    
    Args:
        file_path: Path to the local file to validate.
        
    Returns:
        Tuple of (mime_type, file_size) if valid.
        
    Raises:
        ValueError: If file exceeds size limit or has an unsupported MIME type.
    """
    # Check file size
    file_size = os.path.getsize(file_path)
    if file_size > MAX_FILE_SIZE_BYTES:
        raise ValueError(f"File size {file_size} bytes exceeds the 10 MB limit.")
    if file_size == 0:
        raise ValueError("File is empty.")

    # Detect MIME type using libmagic
    # python-magic reads the file header, not the extension
    mime_type = magic.from_file(file_path, mime=True)
    
    if mime_type not in ALLOWED_MIME_TYPES:
        raise ValueError(f"Unsupported MIME type: {mime_type}. Allowed types: {ALLOWED_MIME_TYPES}")

    return mime_type, file_size

Step 2: Upload the File to Genesys Cloud

The core operation is uploading the file. In the Genesys Cloud API, this is not a standard REST POST with JSON. It is a POST to /api/v2/filestorage/exports/files with multipart/form-data.

The SDK method is post_filestorage_exports_files. This endpoint uploads the file to Genesys Cloud’s secure storage and returns a File object containing the id and uri needed to reference the file in a conversation.

from genesyscloud.platform.client.api.file_storage_api import FileStorageApi
from genesyscloud.platform.client.model.file import File

def upload_file_to_genesys(api_client: ApiClient, file_path: str, conversation_id: str) -> File:
    """
    Uploads a file to Genesys Cloud File Storage.
    
    Args:
        api_client: The initialized Genesys API Client.
        file_path: Path to the validated file.
        conversation_id: The ID of the Web Messaging conversation. 
                         Used for context, though the upload itself is global.
                         
    Returns:
        File object containing the uploaded file's ID and URI.
    """
    file_storage_api = FileStorageApi(api_client)
    
    try:
        # The SDK handles the multipart encoding.
        # 'file_name' is the name of the form field expected by the API.
        # 'file_path' is the path to the file.
        # 'conversation_id' is passed as a custom parameter if you want to tag it,
        # but primarily we need the File object returned.
        
        # Note: The Genesys API for file upload is often accessed via the 
        # 'post_filestorage_exports_files' method in the SDK.
        # However, for Web Messaging specifically, the flow is:
        # 1. Upload file to get a reference.
        # 2. Send that reference in the message payload.
        
        response = file_storage_api.post_filestorage_exports_files(
            file_name="file",  # The form field name
            file_path=file_path
        )
        
        return response

    except ApiException as e:
        if e.status == 400:
            raise RuntimeError(f"Bad Request: The file format or size may be invalid. Details: {e.body}")
        elif e.status == 401:
            raise RuntimeError("Unauthorized: Check your OAuth token and scopes.")
        elif e.status == 403:
            raise RuntimeError("Forbidden: Ensure the 'filestorage:upload' scope is granted.")
        else:
            raise RuntimeError(f"API Error {e.status}: {e.body}")

Step 3: Inject the File Reference into the Conversation

Uploading the file does not automatically send it to the customer. You must update the Web Messaging conversation with a message that includes the file reference.

In Genesys Cloud Web Messaging, messages are sent via the POST /api/v2/conversations/webchat/{webChatId}/messages endpoint. The message body must include the attachments array, referencing the id and uri returned from the upload step.

from genesyscloud.platform.client.api.webchat_api import WebchatApi
from genesyscloud.platform.client.model.webchat_message import WebchatMessage
from genesyscloud.platform.client.model.webchat_message_attachment import WebchatMessageAttachment

def send_file_message(api_client: ApiClient, web_chat_id: str, file_obj: File, sender_name: str = "Support Agent") -> WebchatMessage:
    """
    Sends a message containing the uploaded file attachment to the Web Chat session.
    
    Args:
        api_client: The initialized Genesys API Client.
        web_chat_id: The unique identifier for the Web Chat conversation.
        file_obj: The File object returned from the upload step.
        sender_name: Name of the sender (e.g., Agent or Bot).
        
    Returns:
        The created WebchatMessage object.
    """
    webchat_api = WebchatApi(api_client)
    
    # Construct the attachment object
    attachment = WebchatMessageAttachment(
        id=file_obj.id,
        uri=file_obj.uri,
        name=os.path.basename(file_obj.id), # Use a clean filename
        size=file_obj.size,
        mime_type=file_obj.mime_type
    )
    
    # Construct the message
    message = WebchatMessage(
        sender_name=sender_name,
        text="Please find the attached document.", # Optional text accompanying the file
        attachments=[attachment]
    )
    
    try:
        response = webchat_api.post_conversations_webchat_messages(
            web_chat_id=web_chat_id,
            body=message
        )
        return response
    except ApiException as e:
        if e.status == 404:
            raise RuntimeError(f"Web Chat session {web_chat_id} not found or ended.")
        else:
            raise RuntimeError(f"Failed to send message: {e.body}")

Complete Working Example

Below is the full, runnable script. It combines validation, upload, and message sending. It assumes you have a file named example.pdf in the current directory and an active Web Chat session ID.

import os
import sys
import magic
from genesyscloud.platform.client.configuration import Configuration
from genesyscloud.platform.client.api_client import ApiClient
from genesyscloud.platform.client.rest import ApiException
from genesyscloud.platform.client.api.file_storage_api import FileStorageApi
from genesyscloud.platform.client.api.webchat_api import WebchatApi
from genesyscloud.platform.client.model.webchat_message import WebchatMessage
from genesyscloud.platform.client.model.webchat_message_attachment import WebchatMessageAttachment

# Configuration Constants
ALLOWED_MIME_TYPES = {
    'image/png', 'image/jpeg', 'image/gif', 'application/pdf', 
    'text/plain', 'text/csv', 'application/zip'
}
MAX_FILE_SIZE_BYTES = 10 * 1024 * 1024  # 10 MB

class GenesysFileUploader:
    def __init__(self, client_id: str, client_secret: str, base_url: str = "https://api.us.genesyscloud.com"):
        self.config = Configuration(
            access_token_client_id=client_id,
            access_token_client_secret=client_secret,
            base_url=base_url,
            oauth_client_id=client_id,
            oauth_client_secret=client_secret
        )
        self.api_client = ApiClient(configuration=self.config)

    def validate_file(self, file_path: str) -> tuple[str, int]:
        if not os.path.exists(file_path):
            raise FileNotFoundError(f"File {file_path} does not exist.")
        
        file_size = os.path.getsize(file_path)
        if file_size > MAX_FILE_SIZE_BYTES:
            raise ValueError(f"File size {file_size} bytes exceeds the 10 MB limit.")
        if file_size == 0:
            raise ValueError("File is empty.")

        mime_type = magic.from_file(file_path, mime=True)
        if mime_type not in ALLOWED_MIME_TYPES:
            raise ValueError(f"Unsupported MIME type: {mime_type}. Allowed: {ALLOWED_MIME_TYPES}")
        
        return mime_type, file_size

    def upload_file(self, file_path: str):
        file_storage_api = FileStorageApi(self.api_client)
        try:
            # Upload the file
            file_response = file_storage_api.post_filestorage_exports_files(
                file_name="file",
                file_path=file_path
            )
            return file_response
        except ApiException as e:
            print(f"Upload Error {e.status}: {e.body}")
            raise

    def send_attachment_message(self, web_chat_id: str, file_response, sender_name: str = "System"):
        webchat_api = WebchatApi(self.api_client)
        
        attachment = WebchatMessageAttachment(
            id=file_response.id,
            uri=file_response.uri,
            name=os.path.basename(file_response.id),
            size=file_response.size,
            mime_type=file_response.mime_type
        )
        
        message = WebchatMessage(
            sender_name=sender_name,
            text="Here is your file.",
            attachments=[attachment]
        )
        
        try:
            msg_response = webchat_api.post_conversations_webchat_messages(
                web_chat_id=web_chat_id,
                body=message
            )
            print(f"Message sent successfully. Message ID: {msg_response.id}")
            return msg_response
        except ApiException as e:
            print(f"Message Send Error {e.status}: {e.body}")
            raise

def main():
    # 1. Setup
    client_id = os.getenv("GENESYS_CLIENT_ID")
    client_secret = os.getenv("GENESYS_CLIENT_SECRET")
    
    if not client_id or not client_secret:
        print("Error: Set GENESYS_CLIENT_ID and GENESYS_CLIENT_SECRET env vars.")
        sys.exit(1)

    uploader = GenesysFileUploader(client_id, client_secret)
    
    # 2. Input Parameters
    file_path = "example.pdf"  # Replace with your test file
    web_chat_id = "your-web-chat-session-id-here" # Replace with an active session ID
    
    if not web_chat_id.startswith("your-"):
        print("Warning: Using placeholder web_chat_id. This will fail unless you provide a real ID.")

    try:
        # 3. Validate
        print(f"Validating file: {file_path}")
        mime_type, size = uploader.validate_file(file_path)
        print(f"Validation passed. MIME: {mime_type}, Size: {size} bytes")
        
        # 4. Upload
        print("Uploading file to Genesys Cloud...")
        file_response = uploader.upload_file(file_path)
        print(f"File uploaded successfully. ID: {file_response.id}")
        
        # 5. Send Message
        print("Sending attachment to Web Chat session...")
        uploader.send_attachment_message(web_chat_id, file_response, sender_name="Support Bot")
        
    except Exception as e:
        print(f"Fatal Error: {e}")
        sys.exit(1)

if __name__ == "__main__":
    main()

Common Errors & Debugging

Error: 400 Bad Request on Upload

Cause: The file MIME type is not in the Genesys Cloud whitelist, or the file size exceeds 10 MB.
Fix:

1. Verify the MIME type using python-magic. Genesys Cloud does not trust file extensions.
2. Check the file size. Ensure it is strictly less than or equal to 10,485,760 bytes.
3. If you are uploading a custom document type (e.g., .docx), ensure application/vnd.openxmlformats-officedocument.wordprocessingml.document is in your allowed list and supported by Genesys.

Code Fix:

# Add debugging to see what MIME type python-magic detects
mime = magic.from_file(file_path, mime=True)
print(f"Detected MIME: {mime}")
if mime not in ALLOWED_MIME_TYPES:
    print(f"Rejecting {mime}. Add it to ALLOWED_MIME_TYPES if valid.")

Error: 403 Forbidden on Upload

Cause: The OAuth client lacks the filestorage:upload scope.
Fix:

1. Go to the Genesys Admin Console.
2. Navigate to Admin > Security > OAuth Clients.
3. Select your client.
4. In the Scopes tab, ensure filestorage:upload is checked.
5. Regenerate the client secret if necessary (though scope changes usually apply immediately).

Error: 404 Not Found on Message Send

Cause: The webChatId is invalid or the session has expired.
Fix:

1. Ensure the webChatId is the current, active session ID. Web Chat sessions expire after a period of inactivity (default 5-10 minutes).
2. If the session is expired, you cannot append messages. You must initiate a new Web Chat session from the client side.

Error: File Storage API Not Found

Cause: You are using an older version of the Python SDK that does not include the FileStorageApi module.
Fix:

1. Upgrade the SDK: pip install --upgrade genesys-cloud.
2. Verify the import: from genesyscloud.platform.client.api.file_storage_api import FileStorageApi. If this fails, your SDK version is too old.

Official References

• Genesys Cloud File Storage API Documentation
• Genesys Cloud Web Chat API Documentation
• Python SDK Reference: FileStorageApi
• Web Messaging File Attachments Guide