---
title: Installing Letta from source
slug: guides/server/source
---

<Note>
This guide is intended for developers that want to modify and contribute to the Letta open source codebase.
It assumes that you are on MacOS, Linux, or Windows WSL (not Powershell or cmd.exe).
</Note>

## Prerequisites
First, install uv using the official instructions [here](https://docs.astral.sh/uv/getting-started/installation/).
You'll also need to have [git](https://git-scm.com/downloads) installed.

## Downloading the source code

Navigate to [https://github.com/letta-ai/letta](https://github.com/letta-ai/letta) and click the "fork" button.
Once you've created your fork, you can download the source code via the command line:
```sh
# replace YOUR-GITHUB-USERNAME with your real GitHub username
git clone https://github.com/YOUR-GITHUB-USERNAME/letta.git
```
Creating a fork will allow you to easily open pull requests to contribute back to the main codebase.

Alternatively, you can clone the original open source repository without a fork:
```bash
git clone https://github.com/letta-ai/letta.git
```

## Installing from source
Navigate to the letta directory and install the `letta` package using uv:
```sh
cd letta
uv sync --all-extras
```

## Running Letta Server from source
<Warning>
If you've also installed Letta with `pip`, you may have conflicting installs which can lead to bugs.
To check where your current Letta install is located, you can run the command `which letta`.
</Warning>

Now when you want to use `letta server`, use `uv run` (which will activate the uv environment for the letta server command directly):
```bash
uv run letta server
```
