> For the complete documentation index, see [llms.txt](https://blended.gitbook.io/a1pay/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://blended.gitbook.io/a1pay/request-authentication.md).

# Request Authentication

Every request sent to the A1Pay API must carry the following in the request header

## Header Parameters

**APIKey:** This is the API Key from the developer section in your A1Pay dashboard

**Hash:** This is a SHA256 representation of your APIKey concatenated with your SecretKey also found in your A1Pay dashboard. So you would have something like: \
`var MyHash = SHA256(APIKey + SecretKey);`

**token:** This is the Token provided after successful user login

{% hint style="warning" %}
 All requests to the A1Pay API endpoint must carry these authentication parameters or they will be returned with the error message: "**Unauthorized Request**"
{% endhint %}