I'm trying to solve a problem similar to the ones in this question and this one, basically tracking a sub-session for users by browser tab. The thing I'm trying to accomplish, though, is finding a way to set a request parameter to send back to the server with each request, whether it's a simple synchronous link click, a form post, or an ajax request. What occurred to me as a hopeful solution would be if I could set something in the html head that would be sent each time, though I haven't seen anything to suggest that it's possible. I'm hoping to find a solution that doesn't require wrapping all server requests in some sort of javascript to include the desired parameter.
We're using Rails on the backend.