I don't think you really mean golang.org/x/tools/go/loader or golang.org/x/tools/go/packages are literally undocumented; simply pasting the URL gives you pretty

I don't think you really mean golang.org/x/tools/go/loader or golang.org/x/tools/go/packages are literally undocumented; simply pasting the URL gives you pretty detailed godoc for both packages. Rather, there is no official "how to load Go packages guide" pointing to those packages, and tool developers probably discovered those only by reading other source code. FWIW, the .../loader package is explicitly documented as experimental. The .../packages has a deadline of 1 Dec 2018 for breaking changes (both info found in their respective godoc)