[TheMatten]

What sort of API can be used for this? Is it a special proxy setting, extension or WebDriver client?

[keepamovin]

The network intercepting APIs. Right now we use CDP/RDP and the Fetch domain: https://chromedevtools.github.io/devtools-protocol/tot/Fetch...

There's also somewhat equivalent surface exposed by WebDriver BiDi: https://w3c.github.io/webdriver-bidi/#module-network-command...

If you want to read more about these sorts of protocols, see: https://firefox-source-docs.mozilla.org/remote/index.html

[TheMatten]

Thanks a lot!