How can I dump all garbage responses to txt files?

I read the documentation:

http://guzzle3.readthedocs.org/testing/unit-testing.html

and I know how to use .txt files as response mocks for testing; but what I want to achieve is to capture the actual responses of my application. My webapp relies on hundreds of different API calls, and when one fails it's hard to know where the failure is, so I want to use the .txt response files to "enter" a working response for debugging purposes.

Hope it's clear enough

early.