Voice Agent Function Calling Reference Implementation

This repository serves as a reference implementation for integrating function calling capabilities with Deepgram's Voice Agent API. It demonstrates production-ready patterns for building AI Voice Agent applications with clientside function calling.

Implementation Overview

This reference implementation demonstrates:

• Core function calling patterns with Voice Agent API
• Natural conversation flow using agent filler messages
• Customer information lookup and verification
• Order history retrieval
• Appointment scheduling and management
• Graceful conversation termination through an end_call function

Function Calling Architecture

The implementation uses a three-layer architecture:

• Function definitions that guide the LLM's behavior
• Function handlers that route requests
• Business logic that executes the actual functionality

Natural Conversation Flow

Shows how to implement natural dialogue patterns:

• Agent filler messages for lookup operations
• Proper message sequencing
• Audio completion handling
• Clean session termination

Project Structure

├── business_logic.py     # Core function implementations
├── client.py             # WebSocket client and message handling
├── config.py             # Configuration settings
├── functions.py          # Function definitions and routing

Mock Data System

The implementation uses a mock data system for demonstration:

• Generates realistic customer, order, and appointment data
• Saves data to timestamped JSON files in mock_data_outputs/
• Configurable through config.py

Artificial Delays

The implementation demonstrates how to handle real-world latency:

• Configurable database operation delays in config.py
• Helps simulate production environment timing

Setup Instructions

1. Install the dependencies:

python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

2. Set your Deepgram API key:

export DEEPGRAM_API_KEY=<your-key-here>

Usage

1. Run the client:

   python client.py

2. Use headphones to prevent audio feedback (the agent hearing itself).

Example Interactions

The voice agent handles natural conversations like:

User: "I need to check my order status"
Agent: "Let me look that up for you..."
[Agent executes customer lookup]
Agent: "I can see you have two recent orders. Your most recent 
       order from last week is currently being shipped..."

Configuration

Key settings in config.py:

• ARTIFICIAL_DELAY: Configurable delays for database operations
• MOCK_DATA_SIZE: Control size of generated test data