> For the complete documentation index, see [llms.txt](https://docs.certn.co/api/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.certn.co/api/certn-api-v-1.0/guides/use-the-api/authorization-header.md).

# Use an authorization header

To gain access to our API, you need an [Authorization header](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Authorization)![](/files/i1X0t7ez6Vlx9HiwQQXC) with a valid Bearer token. The token is your [API key](/api/certn-api-v-1.0/guides/use-the-api.md#create-an-api-key).

* Replace `<token>` with your API key in the following header:

```python
{ 'Authorization': 'Bearer <token>' }
```

{% hint style="info" %}
Include this header in every call to our API, and keep it secure. It is your access key.‌
{% endhint %}