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Letta LLM plugin guide

How to use a Letta agent for your LLM with LiveKit Agents.

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OverviewQuick referenceInstallationAuthenticationUsageParametersAdditional resources
Available in
Python

Overview

This plugin allows you to use Letta as an LLM provider for your voice agents. Letta compatibility is provided by the OpenAI plugin using the Letta Chat Completions API.

Quick reference

This section includes a basic usage example and some reference material. For links to more detailed documentation, see Additional resources.

Installation

Install the OpenAI plugin to add Letta support:

uv add "livekit-agents[openai]~=1.3"

Authentication

If your Letta server requires authentication, you need to provide an API key. Set the following environment variable in your .env file:

LETTA_API_KEY

Usage

Use Letta LLM within an AgentSession or as a standalone LLM service. For example, you can use this LLM in the Voice AI quickstart.

from livekit.plugins import openai


session = AgentSession(
    llm=openai.LLM.with_letta(
        agent_id="<agent-id>",
    ),
    # ... tts, stt, vad, turn_detection, etc.
)

Parameters

This section describes some of the parameters for the with_letta method. For a complete list of all available parameters, see the plugin documentation.

agent_idstringRequired

Letta agent ID. Must begin with agent-.

base_urlstringOptionalDefault: https://api.letta.com/v1/voice-beta

URL of the Letta server. For example, your self-hosted server or Letta Cloud.

Additional resources

The following links provide more information about the Letta LLM plugin.

Icon for Python package

Python package

The livekit-plugins-openai package on PyPI.

Plugin reference

Reference for the Letta LLM plugin.

GitHub repo

View the source or contribute to the LiveKit OpenAI LLM plugin.

Letta docs

Letta documentation.

Voice AI quickstart

Get started with LiveKit Agents and Letta.