AI Voice Outbound Agent Builder

Step-by-Step Guide

Follow these steps to create your AI voice outbound agent using the latest technologies.

Environment Setup

Install the required Python libraries for the Retell AI integration.

pip install retell-ai aiohttp

Python 3.8+ required

Retell AI Authentication

Authenticate with your Retell AI API key.

import retell

client = retell.Client(api_key="your_api_key")

Get API key from Retell dashboard

Agent Behavior

Define your agent's persona and conversation flow.

agent_config = {
    "initial_message": "Hello, this is Alex from Customer Support.",
    "voice": "male-1",
    "persona": "friendly and professional"
}

Customize as needed

Sesame AI Integration

Configure the agent to use CSM-1B model.

agent_config["llm"] = {
    "model": "csm-1b",
    "provider": "sesame"
}

Latest Sesame AI model

Outbound Call

Initiate the call with recipient's phone number.

response = client.calls.create(
    phone_number="+15551234567",
    agent_config=agent_config
)

E.164 format required

Call Events

Handle call events and responses.

@client.on("call.connected")
async def handle_connected(call):
    print(f"Call connected: {call.id}")

@client.on("agent.response")
async def handle_response(response):
    print(f"Agent said: {response.text}")

Complete Example

Here's the full implementation you can use as a starting point.

import asyncio
import retell

# Initialize client with your API key
client = retell.Client(api_key="your_api_key_here")

# Configure your agent
agent_config = {
    "initial_message": "Hello, this is Alex calling from Customer Support.",
    "voice": "male-1",
    "persona": "friendly and professional",
    "llm": {
        "model": "csm-1b",
        "provider": "sesame"
    }
}

# Event handlers
@client.on("call.connected")
async def handle_connected(call):
    print(f"Call {call.id} connected to {call.phone_number}")

@client.on("agent.response")
async def handle_response(response):
    print(f"Agent response: {response.text}")

@client.on("call.ended")
async def handle_ended(call):
    print(f"Call {call.id} ended")

async def make_call():
    try:
        # Start the call
        response = await client.calls.create(
            phone_number="+15551234567",  # Replace with actual number
            agent_config=agent_config
        )
        print(f"Call initiated: {response.id}")
    except Exception as e:
        print(f"Error making call: {e}")

# Run the call
asyncio.run(make_call())

Potential Issues & Solutions

API Key Errors

Ensure your API key is correct and has proper permissions. Rotate keys if needed.

Phone Number Format

Use E.164 format (+[country code][number]) for phone numbers.

Model Not Available

Check Retell AI documentation for latest supported models if CSM-1B isn't available.

AI Voice Outbound Agent