Request Header/Query Param Override MV3 is a Chrome extension developed by paulb896. It falls under the category of Browsers and is specifically classified as an Add-ons & Tools subcategory. This extension provides users with the ability to override and add external HTTP request headers and query parameters.

With Request Header/Query Param Override MV3, users can easily manage request headers and query parameters that will be injected into requests made when browsing websites in Chrome. Each override in this extension consists of a header key, header value, and an AJAX Request URL sub-string. The header key and value are associated with each other, and the provided sub-string ensures that the header name and value are only applied to XHR/Fetch requests where the external request URL contains the specified sub-string.

The management of headers is done through the Chrome extension popup, which is a simple React app. The headers are saved to Chrome local storage and are applied to upstream page requests using the chrome declarativeNetRequest request dynamic rules updateDynamicRules function.