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

# Authentication

> How login works.

## Login

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

1. Opens `platform.trycassian.com/cli` in your browser
2. Sign in with Google or email
3. A 6-digit code appears on the page
4. Paste it in your terminal

Your session is stored locally. You stay logged in until you explicitly log out.

## Headless servers

If you're on a machine without a browser:

1. Run `cassian login` and copy the URL it prints
2. Open that URL on any device (phone, laptop, etc.)
3. Sign in, get the code, paste it back

## Logout

```bash theme={null}
cassian logout
```