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

# Authentication

> How to authenticate requests to Forms API.

Forms API uses API-key authentication on protected endpoints:

* `X-API-Key: forms_sk_...`

## How to get an API key

1. Sign in to the app.
2. Go to **Settings**.
3. Open the **API Keys** section.
4. Click **Generate** to create a token.
5. Copy and store it securely (the full key is only shown once).

## API key authentication

Use API keys for server-to-server integrations and backend jobs.

```bash theme={null}
curl -X POST "https://api.sylvian.ai/parse" \
  -H "X-API-Key: forms_sk_your_key" \
  -F "file=@form.pdf"
```

## Choosing between auth modes

* Use API keys when your backend calls Forms API.
* Do not expose API keys in frontend code.

<Warning>
  Never expose API keys in browser code, public repos, screenshots, logs, or client-side analytics.
</Warning>

<Warning>
  Treat API keys like passwords. Anyone with the key can call your API as your account.
</Warning>

## Common auth failures

* `401 Missing or invalid authentication`: no valid API key was provided.
* `401`: API key format is wrong, inactive, or unknown.