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

# Authentication

The Endole API uses HTTP authentication to securely authorise requests. Every request sent to the Endole API must include an `Authorization` header containing your 64-character API key.

## Header Format

Authenticate your requests by including your API key in the `Authorization` header using **Bearer authentication**.

Pass your raw API key directly without any Base64 encoding:

```http theme={null}
Authorization: Bearer YOUR_API_KEY
```

## Example Request

```shellscript theme={null}
curl -X GET "https://api.endole.co.uk/company/01234567/financials" \
     -H "Authorization: Bearer 33e5ea84ca6e9ce3f70b13a4e13d9cf9e451411f1f2140d21e8e5531cd37fec"
```

<Danger>
  Never share your API key or expose it in client-side code (like JavaScript in a web browser). Store keys safely in environment variables on your backend server.
</Danger>