This guide explains how to implement chat functionality using Retell’s Chat API. You’ll learn how to start a chat session, generate responses, and end the session.
1

Create a Chat Agent

Before starting a chat session, you need a chat agent to handle the conversation.For detailed instructions on creating a chat agent, refer to the Create Chat Agent guide.
2

Create a Chat Session

To start a chat session, use the create-chat API endpoint.The API will return a chat_id that you’ll need for subsequent requests.For detailed API information, refer to the Create Chat API Reference.
3

Create a Chat Completion

To generate a response from the chat agent, use the create-chat-completion API endpoint.The API will return the agent’s response in the messages array. All conversation history is automatically stored in Retell’s database, so you don’t need to manage conversation context yourself.For detailed API information, refer to the Create Chat Completion API Reference.
4

Retrieve Chat Details

You can retrieve details about a chat session using the get-chat API endpoint.You can also list all chat sessions using the list-chat endpoint.For detailed API information, refer to the Get Chat API Reference and List Chat API Reference.
5

End Chat Session

When the conversation is complete, end the chat session using the end-chat API endpoint.If Auto-Close Inactive Chats is enabled, chat will automatically end when the timeout is triggered, or you can end them anytime with the end-chat API.For detailed API information, refer to the End Chat API Reference.

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SMS Integration

Retell also supports Twilio SMS integration, allowing you to deploy your chat agents to receive and respond to text messages. To enable SMS functionality for your chat agents, refer to the Enable SMS guide. Once you complete the SMS integration setup, you’ll have access to:
  • Make an outbound SMS button to start a new SMS session
  • Inbound SMS agent configuration
  • Outbound SMS agent configuration
  • Inbound webhook setup for receiving SMS messages