Welcome to Letta

​

What is Letta?

Letta adds state to your LLMs to give them advanced reasoning capabilities and transparent long-term memory.

The Letta open source framework is model-agnostic and white box: as a developer, you can use any LLM you want and have full visibility into the inner workings your LLMs and LLM agents.

Letta is engineered to allow you to quickly build prototypes and scale to production: you can start by prototyping with the Letta CLI and ADE, then deploy a Letta server using Docker to scale your app to thousands of users.

​

Who is Letta for?

Letta is for developers building stateful LLM applications, such as:

• personalized chatbots that require long-term memory and personas that should be updated (self-edited) over time (e.g. companions)
• agents connected to external data sources, e.g. private enterprise deployments of ChatGPT-like applications (connected to your company’s data), or a medical assistant connected to a patient’s medical records
• agents connected to custom tools, e.g. a chatbot that can answer questions about the latest news by searching the web
• automated AI workflows, e.g. an agent that monitors your email inbox and sends you text alerts for urgent emails and a daily email summary

… and countless other use cases!

​

How do I use Letta?

Letta runs as a service: to use Letta, you deploy a Letta server which powers your AI application (web app, mobile app, Discord bot, cron job, etc.). Your application state and LLM calls are managed by the Letta server, and your frontend application connects to the Letta server via the Letta REST APIs.

​

Letta ADE (Agent Development Environment)

The Letta ADE is web application that allows you to create, edit, and monitor agents in your Letta server.

​

Letta API

The Letta server exposes the following REST APIs:

• Agents API: deploy agents with long-term memory, custom tools, access to external data sources (RAG), multi-step reasoning, and more
• Stateful ChatCompletions API: an API designed to be a drop-in replacement for the standard ChatCompletions API

If you’re building an application in Python, you can use the Letta Python SDK to interact with Letta (instead of calling REST APIs directly) for a more seamless experience.

You can also create and interact with Letta agents from the command line using the Letta CLI tool.

​

Getting started

If you’re new to Letta, start by learning the key concepts - or jump straight into creating your first agent!

​

Tutorials

Check out our YouTube channel for more tutorials. If you have an idea for a tutorial, let us know by suggesting an idea on Discord!