> ## Documentation Index
> Fetch the complete documentation index at: https://simplex.sh/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Installation & Authentication

> Install the Simplex Python SDK and CLI, and configure authentication.

## Installation

Install the Simplex Python SDK and CLI from PyPI:

```bash theme={null}
pip install simplex
```

<Note>
  Requires Python 3.9 or higher.
</Note>

After installation, both the Python SDK (`from simplex import SimplexClient`) and the `simplex` CLI command are available.

## Authentication

```bash theme={null}
simplex login
```

This opens a browser-based OAuth flow. Credentials are saved to `~/.simplex/credentials` and used automatically by the SDK and CLI.

If you are working in a headless environment, use the `--api-key` flag:

```bash theme={null}
simplex login --api-key YOUR_API_KEY
```

## Quick verification

After installing and configuring authentication, verify that everything is working:

```bash theme={null}
simplex whoami
simplex workflows list
```

## Next steps

* [CLI Reference](/docs/python-sdk/cli-reference) -- Full reference for all CLI commands
* [TypeScript/Python SDK Examples](/docs/integrating-simplex/typescript-sdk-examples) -- Common integration patterns