Retell AI

API Reference

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Delete Agent

api key

🌟 Unlock the full potential of Retell AI's conversational voice AI API.

Introduction

Pricing

Support

FAQs

Status Page

Understand building blocks Retell provides and what you can do with them.

Quick Start

Try our voice AI in dashboard without coding

Dashboard Tutorial

Documents what can be done to reduce latency in your agent.

Reduce Latency

How to locate and address issues while developing with Retell.

Debug Guide

Overview

Language

Voice

Control and direct how the speech is generated.

Speech Controllability

Interaction Configuration

Understand the constraints and limitations of the agents.

Constraints & Limitations

Create Retell LLM

Prompt Engineering Guide

Tool Calling Overview

How to Add Tool Calling

LLM States

How to Create Multiple LLM States

Dynamic Variables

A step by step guide to create a phone call with Retell managed numbers

Retell Numbers

A step by step guide to integrate custom telephony providers

Custom Telephony

A step by step guide to create a web call with agent using frontend Web SDK

Web Call

Migration Guide

Use webhooks to receive real time events for your call.

Webhook

Custom LLM Overview

Setup WebSocket Server

Integrate LLM

Integrate Function Calling

Troubleshooting Guide

Custom LLM Best Practices

Audio Basics

HIPAA and Privacy

Create Phone Call

Create Web Call

Get Call

List Calls

Retrieve details of a specific Retell LLM

Get Retell LLM

List Retell LLMs

Update Retell LLM

Delete Retell LLM

Create Agent

Get Agent

List Agents

Update Agent

Create Phone Number

Retrieve details of a specific phone number

Get Phone Number

List Phone Numbers

Update agent bound to a purchased phone number

Update Phone Number

Delete Phone Number

Get Voice

List Voices

Retell AI connects with your server, and get responses / actions from your custom LLM.

LLM WebSocket

Get the current concurrency and concurrency limit of the user

Get Concurrency

Create Phone Call (Deprecated)

Register Call To Get CallId To Establish Connection

Register Call (Deprecated)

Get Call (Deprecated)

List Calls (Deprecated)

Retell AI connects with user audio source, read and send audio bytes through this WebSocket.

Audio WebSocket (Deprecated)

Overview of componenets and work needed to create humanlike voice experience

Call (V2)

LLM

Agent

Phone Number

Voice

Custom LLM

Account

Call (V1, Deprecated)

Delete Agent

Authorizations

Path Parameters