Motivation: We want to stop encoding arguments in the request path, and use query parameters instead. This makes more sense for HTTP (and the various proxy layers we have), and is the only way to properly give an origin URL as argument to the API (%2F and / are indistinguishable in Django's request routing). And this will require changing the whole structure of the API.
This meta task lists all other breaking changes we want to include in version 2 of the public API.
1. Use query parameters instead of encoding arguments in the request path
2. No leak of the origin id (use only origin urls)