I don’t think that’s painful at all. Yes you define it as a root class, with dependent classes as needed. This is the contract. It needs to be defined somehow,

I don’t think that’s painful at all. Yes you define it as a root class, with dependent classes as needed. This is the contract. It needs to be defined somehow, and IMO this is as good a way as any. From there on you just use JSON.NET to convert your JSON-string to an instance of the root type, literally one line of code. And after that you get code-completion and type-inference and compile-time checking for all data-object access. It’s an absolute no-brainer.