It'd be neat to extend the warc format and tooling to support cached http responses for things like REST endpoints. Then you could make sure everything you did in a session is recorded for later use.

From the specification it would appear fairly straightforward once an approach was chosen...

Here's the relevant extract from the warc spec that informed my difficulty estimate - "The WARC (Web ARChive) file format offers a convention for concatenating multiple resource records (data objects), each consisting of a set of simple text headers and an arbitrary data block into one long file."

Edit: Upon 2 minutes of reflection I think the way to go for what I'm envisioning is some kind of browser session recording -> replayable archive solution.