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

# Authentication

> How to authenticate with the API

All API endpoints require authentication using an API key. You must include your API key in the `Authorization` header of each request using the Bearer token format.

## Getting an API Key (takes under a minute)

1. Create an account at [openregister.de](https://openregister.de)
2. Go to the [API Keys](https://openregister.de/keys) page
3. Create a new API key

The free plan includes 500 credits per month - perfect for testing and development. For production use, upgrade to the Pro plan. Learn more about [pricing and credit costs](/pricing).

## Using the API Key

Include the API key in the `Authorization` header of all API requests:

```bash theme={"dark"}
Authorization: Bearer YOUR_API_KEY
```

## Next Steps

Got your API key? Head to the [Quickstart Guide](/quickstart) to start making your first requests with our official SDKs or other integrations.