> For the complete documentation index, see [llms.txt](https://developer.betstack.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.betstack.io/sms-notifications/headers.md).

# Headers

In all requests for all types three headers will be sent:

<table><thead><tr><th width="186">Attribute</th><th width="536">Description</th></tr></thead><tbody><tr><td><code>timestamp</code></td><td>The unix time stamp</td></tr><tr><td><code>operator-name</code></td><td>Operator name</td></tr><tr><td><code>signature</code></td><td>Signature of incoming request body and secret key (HMAC)</td></tr></tbody></table>

By checking signature in request you may confirm that the notification came from us.

Detailed info about how to calculate signature may be found on [Signature](/sms-notifications/signature.md) page.