---
title: Run Letta with pip
slug: guides/server/pip
---

<Warning>
**Warning: database migrations are not officially support with `SQLite`!**

When you install Letta with `pip`, the default database backend is `SQLite` (you can still use an external `postgres` service with your `pip` install of Letta by setting `LETTA_PG_URI`).

We do not officially support migrations between Letta versions with `SQLite` backends, only `postgres`.
If you would like to keep your agent data across multiple Letta versions we highly recommend using the [Docker install method](/server/docker) which is the easiest way to use `postgres` with Letta.
</Warning>

## Installing and Running the Letta Server

When using Letta via [Docker](/guides/server/docker) you don't need to install Letta, instead you simply download the Docker image (done automatically for you when you run `docker run`).

When using Letta via `pip`, running the Letta server requires you first install Letta (via `pip install`).
After installing, you can then run the Letta server with the `letta server` command.

<Steps>
  <Step title="Install using pip">
    To install Letta using `pip`, run:
    ```
    pip install -U letta
    ```
  </Step>
  <Step title="Configure model providers">
    Set environment variables to enable model providers, e.g. OpenAI:
```sh
# To use OpenAI
export OPENAI_API_KEY=...

# To use Anthropic
export ANTHROPIC_API_KEY=...

# To use with Ollama
export OLLAMA_BASE_URL=...

# To use with Google AI
export GEMINI_API_KEY=...

# To use with Azure
export AZURE_API_KEY=...
export AZURE_BASE_URL=...

# To use with vLLM
export VLLM_API_BASE=...
```

    If you have a PostgreSQL instance running, you can set the `LETTA_PG_URI` environment variable to connect to it:
    ```bash
    export LETTA_PG_URI=...
    ```
  </Step>
  <Step title="Run the Letta server">
    To run the Letta server, run:
    ```bash
    letta server
    ```
    You can now access the Letta server at `http://localhost:8283`.
  </Step>
</Steps>