Building Voice AI with Webex Contact Center BYOVA and AWS Lex: A Complete Developer Guide

Transform your contact center with intelligent voice interactions using Webex Contact Center’s BYOVA (Bring Your Own Virtual Agent) feature and AWS Lex.

Table of Contents

  1. Introduction
  2. Prerequisites
  3. Step 1: Setting Up Your Webex Contact Center Sandbox
  4. Step 2: Configuring BYOVA and BYODS
  5. Step 3: Testing with Local Audio Connector
  6. Step 4: Setting Up AWS Lex
  7. Step 5: Configuring the BYOVA Gateway
  8. Step 6: Testing Your Integration
  9. Troubleshooting
  10. Next Steps
  11. Conclusion

Introduction

Webex Contact Center’s BYOVA (Bring Your Own Virtual Agent) feature allows you to integrate your own AI-powered voice agents directly into your contact center workflows. Combined with AWS Lex, you can create sophisticated conversational AI experiences that handle customer inquiries, route calls, and provide intelligent responses.

This guide will walk you through the complete process of:

  • Setting up a Webex Contact Center sandbox environment
  • Configuring BYOVA and BYODS (Bring Your Own Data Source)
  • Creating and configuring a AWS Lex bot
  • Deploying and configuring the BYOVA Gateway
  • Testing your voice AI integration end-to-end

What You’ll Build: A fully functional voice AI system where customers can call your contact center, interact with an AWS Lex-powered virtual agent, and seamlessly transfer to human agents when needed.

Prerequisites

Before starting, ensure you have:

  • Webex Account: A free Webex account (create one at webex.com if needed)
  • AWS Account: An active AWS account with appropriate permissions
  • Development Environment:
    • Python 3.8 or higher
    • Git
    • Terminal/Command Prompt access
  • Basic Knowledge: Familiarity with:
    • Webex Contact Center concepts
    • AWS services (Lex, IAM)
    • Python development
    • gRPC and REST APIs

Step 1: Setting Up Your Webex Contact Center Sandbox

1.1 Request a Sandbox

  1. Sign in to Webex Developer Portal
  2. Navigate to Contact Center Sandbox
  3. Complete the Request Process
    • Read and accept the Terms and Conditions
    • Check “By creating this app, I accept the Terms of Service”
    • Click “Request a Sandbox”
  4. Wait for Provisioning
    • Sandbox creation takes up to 15 minutes
    • You’ll receive several emails with account details
    • Save the final provisioning email - it contains critical information

1.2 Access Your Sandbox

Your provisioning email will contain:

Administrator Account:

  • Username: admin@xxxxxx-xxxx.wbx.ai
  • Password: ********
  • Webex Site URL: xxxxxx-xxxx.webex.com

Agent Accounts:

  • Premium Agent: user1@xxxxxx-xxxx.wbx.ai (Extension: 1001)
  • Supervisor Agent: user2@xxxxxx-xxxx.wbx.ai (Extension: 1002)

Phone Numbers:

  • Main PSTN Number: +1nnnnnnnnnn (for Webex calling)
  • Entrypoint Number: +1nnnnnnnnnn (for Contact Center)

1.3 Access the Administrator Portal

  1. Open a Private/Incognito Browser Window
    • Chrome: Ctrl+Shift+N (Windows) or Cmd+Shift+N (Mac)
    • Firefox: Ctrl+Shift+P (Windows) or Cmd+Shift+P (Mac)
  2. Navigate to the Administrator Portal
  3. Verify Access
    • You should see the Webex Contact Center Administrator Portal
    • Note the site configuration and available features

Step 2: Configuring BYOVA and BYODS

2.1 Understanding BYOVA and BYODS

  • BYOVA (Bring Your Own Virtual Agent): Allows you to integrate external AI services as virtual agents
  • BYODS (Bring Your Own Data Source): Enables integration with external data sources for enhanced AI capabilities
    • BYOVA builds on top of the BYODS framework
    • Provides secure, standardized data exchange between Webex and third-party providers
    • Uses JWS (JSON Web Signature) tokens for authentication
    • Requires Service App creation and admin authorization

Important: BYOVA requires BYODS setup first, as the virtual agent configuration depends on having a registered data source.

2.2 Create a Service App for BYODS

Before configuring BYOVA, we need to set up a Service App for data source integration, as BYOVA builds on top of the BYODS (Bring Your Own Data Source) framework.

  1. Navigate to Webex Developer Portal
  2. Create a New Service App
    • Go to My Apps → Create a New App
    • Choose Service App as the application type
  3. Configure the Service App
    • Name: BYOVA Gateway Service App (or your preferred name)
    • Scopes: Ensure you select:
      • spark-admin:datasource_read
      • spark-admin:datasource_write
    • Domains: Specify your gateway domain (e.g., your-domain.com or ngrok-free.app)
      • Avoid registering ports in the domain - all ports will be accepted later
    • Data Exchange Schema: Select VA_service_schema for voice virtual agent interactions
      • This schema (ID: 5397013b-7920-4ffc-807c-e8a3e0a18f43) is specifically designed for voice virtual agent services
      • Reference: VoiceVirtualAgent Schema
    • Complete any other required information
  4. Save the Service App Client ID and Client Secret
    • Under Authentication, locate the Client ID and Client Secret
    • Save these credentials for later use
  5. Submit for Admin Approval
    • In your sandbox, select “Request Admin Approval”
    • This makes the Service App visible in Control Hub for admin authorization

2.3 Register Your Data Source

  1. Get Admin Authorization
    • In Control Hub (admin.webex.com), navigate to Apps → Service Apps
    • Find your Service App and click “Authorize”
    • This generates org-specific access and refresh tokens
  2. Get Service App Token
    • After admin approval, return to developer.webex.com
    • Go to My Apps and select your Service App
    • Under Org Authorizations, locate your org in the list and select it
    • Paste the Client Secret from step 1 into the Client Secret field and click “Generate Tokens”
    • Save the returned access_token - you’ll need it to register your data source
    • Note: Tokens expire and will need to be refreshed using the refresh token provided
  3. Register the Data Source
    • Use the access token from step 1 to register your data source
    • Make a POST request to /v1/datasources with the following payload:
    • API Reference: Register a Data Source
    {
  "schemaId": "5397013b-7920-4ffc-807c-e8a3e0a18f43",
  "url": "https://your-gateway-ip:50051",
  "audience": "BYOVAGateway",
  "subject": "callAudioData",
  "nonce": "123456",
  "tokenLifetimeMinutes": "1440"
}
    • Save the data source ID for later use

Reference: For detailed BYODS setup instructions, see the Bring Your Own Data Source documentation.

2.4 Configure BYOVA Virtual Agent

  1. Navigate to Virtual Agents
    • In Control Hub, go to Contact Center → Integrations → Features
    • Click “Create Feature”
  2. Configure Virtual Agent Settings
    • Name: AWS Lex Virtual Agent
    • Type of Connector: Select “Service App”
    • Authorized Service App: Select your Service App from step 2.2
    • Resource Identifier: Enter the data source ID you saved in step 2.3
    • Click “Create”

2.5 Import the BYOVA Flow Template

  1. Navigate to Control Hub
  2. Access Contact Center Flows
    • In Control Hub, navigate to Contact Center
    • Click on Flows
    • Select Manage Flows
    • Click Import Flow

    Reference: For detailed information about Flow Designer and flow management, see the Build and manage flows with Flow Designer documentation.

  3. Import the BYOVA Flow Template
    • Download the BYOVA_Gateway_Flow.json file from the gateway repository (located in the project root)
    • In the import dialog, choose the BYOVA_Gateway_Flow.json file
    • The flow will be imported with the name “BYOVA”
  4. Configure the Virtual Agent
    • In the imported flow, locate the VirtualAgentV2_q2c activity
    • Click on the activity to open its properties
    • Update the Virtual Agent selection:
      • Connector Name: Select your BYOVA connector (e.g., “AWS Lex Connector”)
      • Virtual Agent ID: Select your configured virtual agent
    • Save the activity configuration
  5. Review Flow Structure The imported flow includes:
    • Start: Entry point for calls
    • Virtual Agent: Routes to your BYOVA virtual agent
    • Decision Logic: Handles agent disconnection and transfer scenarios
    • Play Message: Provides feedback to callers
    • End: Terminates the call
  6. Save and Activate the Flow
    • Save your flow configuration
    • Activate the flow for testing

2.6 Assign Flow to Entry Point

  1. Navigate to Channels
    • In Control Hub, go to Contact Center → Channels
    • Select Entry Point 1 (or your configured entry point)
  2. Configure Entry Point Routing
    • In the Entry Point 1 configuration, locate the Routing Flow setting
    • Change the routing flow from the default to your BYOVA flow
    • Save the configuration
  3. Verify Assignment
    • Confirm that Entry Point 1 is now using the BYOVA flow
    • The entry point will now route calls through your virtual agent integration

Step 3: Testing with Local Audio Connector

Before setting up AWS Lex, let’s test the BYOVA integration using the local audio connector. This allows you to verify that your BYOVA configuration is working correctly with pre-recorded audio files.

3.1 Configure the Local Audio Connector

  1. Update Gateway Configuration
    • Edit config/config.yaml to ensure the local audio connector is enabled
    • The local connector should already be configured by default:
    connectors:
  local_audio_connector:
    type: "local_audio_connector"
    class: "LocalAudioConnector"
    module: "connectors.local_audio_connector"
    config:
      audio_files:
        welcome: "welcome.wav"
        transfer: "transferring.wav"
        goodbye: "goodbye.wav"
        error: "error.wav"
        default: "default_response.wav"
      agents:
        - "Local Playback"
  2. Prepare Audio Files
    • Ensure audio files are in the audio/ directory
    • Default files should already be present:
      • welcome.wav - Welcome message
      • default_response.wav - Response messages
      • goodbye.wav - Goodbye message
      • transferring.wav - Transfer message
      • error.wav - Error message

3.2 Start the Gateway

  1. Activate Virtual Environment 
    source venv/bin/activate
  2. Start the Gateway 
    python main.py
  3. Verify Startup
    • Check that both gRPC server (port 50051) and web interface (port 8080) are running
    • Access the monitoring interface at http://localhost:8080

3.3 Test the Local Connector

  1. Make a Test Call
    • Call the entrypoint number from your sandbox provisioning email
    • You should hear the welcome message from the local audio connector
  2. Verify Audio Playback
    • The local connector will play the configured audio files
    • Check the monitoring interface for active connections
    • Review logs to ensure proper audio file playback
  3. Test Flow Integration
    • Verify the call flows through your imported BYOVA flow
    • Test different scenarios (welcome, responses, goodbye)
    • Ensure proper call termination

3.4 Troubleshoot Local Connector Issues

Common Issues:

  • No Audio: Check that audio files exist in the audio/ directory
  • Wrong Audio: Verify audio file names match the configuration
  • Connection Issues: Ensure the gateway is accessible from Webex Contact Center

Debug Commands:

# Check gateway status
curl http://localhost:8080/api/status

# View available agents
curl http://localhost:8080/api/agents

# Check active connections
curl http://localhost:8080/api/connections

Once the local connector is working correctly, you can proceed to set up AWS Lex for more sophisticated voice AI interactions.

Step 4: Setting Up AWS Lex

4.1 Create a AWS account

If you already have an AWS account, skip this step. If you don’t have an AWS account, use the following procedure to create one.

  1. Open https://portal.aws.amazon.com/billing/signup.

  2. Follow the online instructions. Part of the sign-up procedure involves receiving a phone call or text message and entering a verification code on the phone keypad.

    When you sign up for an AWS account, an AWS account root user is created. The root user has access to all AWS services and resources in the account. As a security best practice, assign administrative access to a user, and use only the root user to perform tasks that require root user access.

4.2 Create Your AWS Lex Bot

You can create a bot with Amazon Lex V2 in multiple ways. If you want to learn more about all the ways, refer to this guide.

In this section, you create an Amazon Lex bot (BookTrip).

  1. Sign in to the AWS Management Console and open the Amazon Lex console at https://console.aws.amazon.com/lex/.

  2. On the Bots page, choose Create.
  3. On the Create your Lex bot page,
    • Choose BookTrip blueprint.
    • Leave the default bot name (BookTrip).

  4. Choose Create. The console sends a series of requests to Amazon Lex to create the bot. Note the following:

  5. The console shows the BookTrip bot. On the Editor tab, review the details of the preconfigured intents (BookCar and BookHotel).

  6. Test the bot in the test window.

If you would like to use generative AI to optimize LexV2 bot creation and performance, please refer to this guide

If you wish to use AWS Bedrock Agents with a custom knowledge base—as part of your autonomous bot workflow, here are some guides that can help you setup agents and knowledge base

4.3 Lex Bot Configuration & Testing

Once you have successfully created the Lex bot following the documentations provided above, please make sure to add Agent Intent to your bot.

  1. Sign in to the AWS Management Console and open the Amazon Lex console at https://console.aws.amazon.com/lex/.

  2. From the list of bots, choose the bot that you created, then from Add languages choose View languages.

  3. Choose the language to add the intent to, then choose Intents.
  4. Choose Add intent, give your intent a name, and then choose Add.

  5. Add Sample Utterances

    Agent
Can I talk to an agent
Can I talk to a person
Representative please
Connect me to a person

    Feel free to add or remove utterances, but please keep it specific to the agent

  6. Set up Fulfillment response
    • On successful fulfillment 
      Okay, transferring you to a human agent.
    • In case of failure 
      I'm sorry, but I couldn't connect you to a human agent. Please try again.

After creation, test your bot inside the AWS Lex UI and ensure that all basic and agent-related intents work as expected.

4.4 Collect Lex Bot Identifiers

Once your bot is ready, note the following identifiers:

  • Bot name
  • Bot ID
  • Bot alias name
  • Alias bot ID

You will enter these into your Webex Lex connector configuration.

4.5 IAM Policy and Permissions

The AWS Lex connector requires specific IAM permissions to discover bots, retrieve aliases, and process conversations. You have two options:

Option 1: Use Managed Policy (Easiest)

Attach these managed policies to your IAM user or role:

  • AmazonLexFullAccess - Provides all necessary Lex permissions
  • AmazonPollyReadOnlyAccess - Required for text-to-speech features (optional)

For tighter security control, create a custom IAM policy with only the required permissions:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "lex:ListBots",
        "lex:ListBotAliases",
        "lex:RecognizeUtterance",
        "lex:RecognizeText"
      ],
      "Resource": "*"
    }
  ]
}

Required Permissions Explained:

  • lex:ListBots - Allows the connector to discover available bots in your AWS account
  • lex:ListBotAliases - Required for automatic bot alias discovery (new feature)
  • lex:RecognizeUtterance - Allows sending audio/text to bots and receiving responses
  • lex:RecognizeText - Allows text-based interactions with bots

Optional Permissions:

If you’re using Polly for text-to-speech features, add:

{
  "Effect": "Allow",
  "Action": [
    "polly:SynthesizeSpeech"
  ],
  "Resource": "*"
}

For Bedrock/Advanced Integrations:

If your Lex bot uses Amazon Bedrock agents, you may need additional policies. Refer to AWS Bedrock Agent Permissions Documentation for details.

Note: The connector automatically discovers bot aliases. If you encounter permission errors during bot discovery, ensure your IAM user/role has the lex:ListBotAliases permission.

4.6 Create access keys

  1. Use your AWS account ID or account alias, your IAM user name, and your password to sign in to the IAM console.

  2. In the navigation bar on the upper right, choose your user name, and then choose Security credentials.

  3. In the Access keys section, choose Create access key. If you already have two access keys, this button is deactivated and you must delete an access key before you can create a new one.

  4. On the Access key best practices & alternatives page, choose your use case to learn about additional options which can help you avoid creating a long-term access key. If you determine that your use case still requires an access key, choose Other and then choose Next.

  5. (Optional) Set a description tag value for the access key. This adds a tag key-value pair to your IAM user. This can help you identify and update access keys later. The tag key is set to the access key id. The tag value is set to the access key description that you specify. When you are finished, choose Create access key.

  6. On the Retrieve access keys page, choose either Show to reveal the value of your user’s secret access key, or Download .csv file. This is your only opportunity to save your secret access key. After you’ve saved your secret access key in a secure location, choose Done.

Please save this Access Key and Secret Access Key very safely.

Step 5: Configuring the BYOVA Gateway

5.1 Clone and Set Up the Gateway

  1. Clone the Repository 
    git clone https://github.com/your-org/webex-byova-gateway-python.git
cd webex-byova-gateway-python
  2. Create Virtual Environment 
    # Create virtual environment
python -m venv venv
   
# Activate virtual environment (REQUIRED)
# On macOS/Linux:
source venv/bin/activate
# On Windows:
# venv\Scripts\activate
   
# Verify activation - you should see (venv) in your prompt
which python  # Should show path to venv/bin/python
  3. Install Dependencies 
    pip install -r requirements.txt
  4. Generate gRPC Stubs 
    python -m grpc_tools.protoc -I./proto --python_out=src/generated --grpc_python_out=src/generated proto/*.proto

5.2 Configure AWS Lex Connector

  1. Set AWS Credentials 
    # Set environment variables (recommended for production)
export AWS_ACCESS_KEY_ID=your_access_key_here
export AWS_SECRET_ACCESS_KEY=your_secret_key_here
export AWS_DEFAULT_REGION=us-east-1
  2. Update Configuration File Edit config/config.yaml: 
    # Gateway settings
gateway:
  host: "0.0.0.0"
  port: 50051

# Monitoring interface
monitoring:
  enabled: true
  host: "0.0.0.0"
  port: 8080

# Connectors
connectors:
  # AWS Lex Connector
  aws_lex_connector:
    type: "aws_lex_connector"
    class: "AWSLexConnector"
    module: "connectors.aws_lex_connector"
   config:
     region_name: "us-east-1"  # Your AWS region
     # Note: Bot aliases are discovered automatically. The connector uses the most recent alias for each bot.
     initial_trigger_text: "hello"  # Text sent when starting conversation
     barge_in_enabled: false
     audio_logging:
        enabled: true
        output_dir: "logs/audio_recordings"
        filename_format: "{conversation_id}_{timestamp}_{source}.wav"
        log_all_audio: true
        max_file_size: 10485760
        sample_rate: 8000
        bit_depth: 8
        channels: 1
        encoding: "ulaw"
      agents: []

5.3 Configure Network Access

  1. Determine Your Gateway’s IP Address 
    # On macOS/Linux:
ifconfig | grep "inet " | grep -v 127.0.0.1
   
# On Windows:
ipconfig
  2. Update Webex Contact Center Configuration
    • In the Administrator Portal, update your virtual agent endpoint
    • Use: http://your-gateway-ip:50051
  3. Configure Firewall (if needed)
    • Ensure port 50051 is accessible from Webex Contact Center
    • For testing, you may need to configure port forwarding

5.4 Start the Gateway

  1. Start the Server 
    # Ensure virtual environment is activated
source venv/bin/activate
   
# Start the gateway
python main.py
  2. Verify Startup
    • You should see output indicating both gRPC and web servers are running
    • Check the monitoring interface at http://localhost:8080
  3. Test Gateway Status 
    # Test the API
curl http://localhost:8080/api/status
   
# Check available agents
curl http://localhost:8080/api/agents

Step 6: Testing Your Integration

6.1 Set Up Agent Desktop

  1. Install Webex Contact Center Desktop
    • Download from the Administrator Portal
    • Install on a test machine
  2. Log in as Agent
    • Use the Premium Agent credentials from your provisioning email
    • Enter the extension number (1001)
  3. Set Agent Status to Available
    • Ensure the agent is ready to receive calls

6.2 Test the Voice AI Integration

  1. Make a Test Call
    • Call the entrypoint number from your provisioning email
    • You should hear the default greeting
  2. Interact with the Virtual Agent
    • Speak naturally to test your AWS Lex bot
    • Try various utterances you configured
    • Test the conversation flow
  3. Test Agent Transfer
    • Request to speak to a human agent
    • Verify the call transfers to your logged-in agent

6.3 Monitor the Integration

  1. Use the Monitoring Interface
    • Open http://localhost:8080 in your browser
    • Monitor active connections and session data
  2. Check Logs
    • Review gateway logs for any errors
    • Check AWS CloudWatch logs for Lex activity
  3. Verify Audio Quality
    • Test audio clarity and response times
    • Check audio recordings in logs/audio_recordings/

Troubleshooting

Common Issues and Solutions

1. Gateway Won’t Start

Problem: python: command not found or import errors Solution: Ensure virtual environment is activated

source venv/bin/activate
which python  # Should show venv path

2. AWS Lex Connection Issues

Problem: Authentication or region errors Solution: Verify AWS credentials and region

aws sts get-caller-identity  # Test AWS credentials

3. Webex Contact Center Can’t Reach Gateway

Problem: Connection timeout or refused Solution: Check network configuration

  • Verify gateway IP address
  • Ensure port 50051 is accessible
  • Check firewall settings

4. Audio Quality Issues

Problem: Poor audio quality or delays Solution: Check audio configuration

  • Verify sample rate (8000 Hz)
  • Check encoding (u-law)
  • Review network latency

5. Bot Not Responding

Problem: Lex bot doesn’t respond to utterances Solution: Check bot configuration

  • Verify bot alias ID
  • Test bot in Lex console
  • Check intent configuration

Debug Commands

# Check gateway status
curl http://localhost:8080/api/status

# View active connections
curl http://localhost:8080/api/connections

# Check debug information
curl http://localhost:8080/api/debug/sessions

# Test AWS credentials
aws sts get-caller-identity

# Check Lex bot status
aws lex-models-v2 describe-bot --bot-id YOUR_BOT_ID

Next Steps

Enhance Your Integration

  1. Add Advanced Features
    • Implement sentiment analysis
    • Add multi-language support
    • Integrate with CRM systems
  2. Scale Your Solution
    • Deploy to production AWS environment
    • Implement load balancing
    • Add monitoring and alerting

3.. Customize the Gateway

  • Add new connector types
  • Implement custom audio processing
  • Add advanced logging and analytics

Production Considerations

  1. Security
    • Use IAM roles instead of access keys
    • Implement proper authentication
    • Encrypt sensitive data
  2. Monitoring
    • Set up CloudWatch alarms
    • Implement health checks
    • Add performance metrics
  3. Scalability
    • Use auto-scaling groups
    • Implement load balancing
    • Plan for high availability

Conclusion

You’ve successfully set up a complete voice AI integration using Webex Contact Center BYOVA and AWS Lex! This powerful combination allows you to:

  • Provide 24/7 intelligent customer service with AI-powered virtual agents
  • Seamlessly transfer complex inquiries to human agents when needed
  • Scale your contact center without proportional increases in staff
  • Improve customer satisfaction with faster response times and consistent service

The BYOVA Gateway provides a flexible foundation that you can extend and customize for your specific needs. Whether you’re building a simple FAQ bot or a complex conversational AI system, this architecture gives you the tools to succeed.

Resources

Support

For questions about this integration:

  • Check the troubleshooting section above
  • Review the gateway logs and monitoring interface
  • Consult the AWS Lex and Webex Contact Center documentation
  • Reach out to the developer community for assistance

Happy building! 🚀

This guide provides a comprehensive walkthrough for integrating AWS Lex with Webex Contact Center using the BYOVA Gateway. The setup process is designed to be developer-friendly while following enterprise best practices for security and scalability.