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I am trying to develop a Safari Extension that can save a file from a webpage into persistent storage with minimal user input. Problem I don't know how to code it so that it results like manually saving a file from the "Sources" tab in Safari Web Inspector. Equivalent manual steps show source or resources of page by keying ⌥⌘U or ⌥⌘A or by navigating to Web Inspector then "Sources" save the file by selecting the file then by keying ⌘S or by secondary clicking the file then clicking "Save File" Alternative solution Javascript get the URL of files from the HTML elements and then pass the URL to a downloader, but I don't want to download it after the browser already did. I want to save the already downloaded temporary files to reduce network trafficking. Theory From my current understanding, when a webpage is viewed, Safari downloads the files and loads them in memory. Other I tried multiple ways to Google it but I keep getting only unrelated results. Thank you for your time to read this and in advance.