> ## Documentation Index
> Fetch the complete documentation index at: https://docs.retellai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Retell AI API Reference

> Reference for the Retell AI API: authentication, base URL, SDKs, and endpoints for building and managing voice and chat agents programmatically.

Use this section to build and manage Retell AI voice and chat agents programmatically.

## What you can do

* Create, update, and manage calls and chats
* Configure voice agents and chat agents
* Manage phone numbers, voices, and knowledge bases
* Run tests and retrieve test run results
* Integrate custom telephony and custom LLM workflows

## Getting started

If you are new to the API:

1. Create your API key in the dashboard.
2. Make your first request with the `Create phone call` endpoint.
3. Use the grouped endpoint sections in the sidebar to expand your integration.