Is there any way to automatically generate har files? [closed]
We just did this recently with Firebug and NetExport:
http://www.softwareishard.com/blog/netexport/
You can configure NetExport to automatically export HAR files to a specified directory (compression optional). This has been useful for us in getting samples of resource loading data for particular web apps.
Have a look at the BrowserMob Proxy or run a private instance of WebPageTest and use WPT Monitor with it
PhantomJS (headless Webkit-browser on Node.js) can export .har files directly.
This way you should be able to build a tool that returns a .har-file for a given URL...