Simple-Header-Payload is a free Chrome browser extension developed by CAMYA. This extension allows users to send user-defined HTTP request headers with a user-defined payload string to a user-defined host. It is designed for productive, live, development, debug, and maintenance situations where users want to restrict or allow access to resources on their website.

With Simple-Header-Payload, users can easily add custom HTTP header name/value pairs or append a value to the User-Agent. They can activate and deactivate entries, and the extension highlights matched host entries for easy identification. The extension also offers a random payload string generator and allows inline-editing of the payload string. Users can set optional titles and comments for their entries and have the option to show or hide the payload string in the host list. Additionally, there is an option to reset extension settings if needed.

To use the extension, users simply need to open it with a left mouse click on its icon and click the "+ Add new host" button. They can then fill out the form with their data, with only the Host / IP field being required, and click the "Add" button to add the host entry to their host list.

The extension works by adding the user-configured payload data to the requests for the specific host only. It only adds the user-defined header data if the host of a browser tab matches the one from the host config. All data of the extension is stored internally in the browser extension itself, ensuring privacy and security.

Simple-Header-Payload is a valuable tool for users who need to customize their HTTP headers on the web server level. It can be used with popular server configurations like Apache, Nginx, or Litespeed, as well as with scripting languages like PHP, Python, Perl, and more. The extension provides implementation examples and comprehensive documentation on the CAMYA website.