Letta Code

Letta Code allows you to create self-improving, stateful coding agents that can learn from experience and improve with use. Unlike Claude Code, Letta Code is open source, model agnostic (you can use it with any model!), and most importantly, is stateful, meaning that you can use the same agent across many coding sessions, and have it learn and improve over time.

All Letta Code agents are Letta agents, to you can easily build applications around them using the rich Letta API (Letta Code itself is built on the Letta TypeScript SDK). You can also use Letta Code as a CLI harness to connect any Letta agent (even non-coding agents) to your terminal. This means that if you have stateful agents running in Letta, you use any of them via the CLI to give them access to your computer.

Get started

Requirements:

• Node.js (version 18+)
• A Letta Developer Platform account

To install or update Letta Code, use npm install:

Install with npm

npm install -g @letta-ai/letta-code

If you haven’t used Letta Code before, follow the instructions to login via OAuth. Alternatively, you can set a valid LETTA_API_KEY in your environment.

To use Letta Code, simply navigate to a directory you want to work in, then run letta to start:

Using Letta Code

cd your-coding-project
letta