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

# Authentication

> How to authenticate with the API

## Authentication

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

1. [Click here](https://registercheck.de/api-management) and create an account
2. Upgrade to Pro
3. Create a new api key

### Using the API Key

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

```
Authorization: Bearer YOUR_API_KEY
```