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

# missing_required_header

> A required HTTP header is missing from your Unkey API request. Check the API reference for required headers like Authorization and Content-Type.

<Danger>`err:user:bad_request:missing_required_header`</Danger>