Observe any XHR request using a node process?

I am building a development tool, and would like to monitor requests to specific domains on a user's system.

I have already written a MITM proxy server. I would like to observe all requests to, say, api.twitter.com, without requiring users to change their code to point to my proxy server. This might be called an HTTP sniffer, I'm not sure.

I have considered:

• Browser plugin (eg: chrome dev tools plugin)


• /etc/hosts (but this can't map domain to domain I think, and if you did you wouldn't be able to get to the original one)


• Native OSX app (learning curve)

Is there a way to observe system HTTP requests using node? I don't know where to start.