Passively capture, archive, and hoard your web browsing history, including the contents of the pages you visit, for later offline viewing, mirroring, and/or indexing. Your own personal private Wayback Machine that can also archive HTTP POST requests and responses, as well as most other HTTP-level data.
Just a tiny patch for Firefox-based browsers that makes them always give raw requestBody (instead of just formData) to the webRequest.onBeforeRequest handlers of WebExtensions API.