Package Management in code question

I'm working on something that needs to download transport.zip files from the repository.

I've got it working for the current version of a package, but when you query the rest server with the package name, you only get the most recent version of the package (plus any other packages that contain the package name).

I need to get older versions too. I'm currently using a version of the download processor to grab the HTML of the "previous versions" page at modx.com/extras and scraping the HTML to get the package signatures and IDs. It works, but it's very slow. I'm hoping there's a way to query the rest server for a particular version of a package.

Does anyone know a way to get a specific version (including older versions) given the signature with no extra baggage?

We could really use some good documentation on the rest API, since AFAIK, the code isn't available.

Great question... +1 on documentation request...