[andersriutta]

"JSON schema seeming to finally gain traction"

Could you describe this further? Are you referring to http://json-schema.org/ or to more general efforts to bring typing to APIs, like GraphQL?

[hyperpallium]

Sorry for late reply. I meant the former, json-schema. It's the one that seems to get used.

Other approaches might be better, esp for specific uses, but most people just want some typing, and json schema is closest to it. I hadn't heard of "GraphQL".