Hoping someone else chimes in with how to stick a redirect into a proxy,

Nothing to do with Twisted, per se. A proxy is a two-way conduit: 1. Receive a request from A 2. Massage and/or log the request as necessary 3. Make a request to B. 4. Receive the response from B. 5. Massage and/or log the response as necessary 6. Return the response to A. It looks like this is just for the web browsers (i.e., HTTP protocol). If so, then at step 2 you would make your test. If you decide A should go to the "required reading" URL instead of the requested URL, simply skip steps 3-5 and return a valid HTTP document with a "moved temporarily" code (30x, I think). The browser will then request the other URL. The one catch is that, depending on the browser, the user may get the same page if they request the original URL again in the same browser window/session. If that's the case, they would need to open a new window to get to the original URL. - Sam