I wrote a proxy to make it easier to use (https://github.com/jpsingleton/Huxley). Been meaning to port it to .NET Core when I find the time. There is also an old Python client here: https://github.com/HackPartners/darwinrest
You can find many more resources in the community (https://wiki.openraildata.com/ https://github.com/openraildata https://groups.google.com/forum/#!forum/openraildata-talk). We're pretty friendly, say hi.