Version endpoint for a given deployment?

Our project is starting to get into a situation where the same code base needs to generate states for different deployments of neuroglancer that have conflicting state properties and aspects like JSON url handling. In order to better handle this, I was looking for an endpoint on a given neuroglancer deployment that would carry version information or similar metadata that could be parsed in a straightforward manner in order to select the right behavior for a given deployment URL. I do see that neuroglancer-demo.appspot.com has a `built info` section in the help panel, although our deployments don't show a version there, so perhaps it is not a mandatory build parameter. I also don't see a particularly simple mechanism to access this information programmatically.

Do you have a suggestion for a good approach to doing this with the existing code, or possibly adding a adding a very light `/info` or `/version` type endpoint that could just host build version number and perhaps buildtime metadata?