Is there not a setContentType for the Response object in SS2.0?

maybe you just set the HTTP response header naturally?

I'll try that

I hope that works, as I think having a separate dedicated method for doing the same thing doesn't add much except make one have to ask questions. Bad API design for the modern days imho

in a suitelet

ctx.response.setHeader({ name: 'content-type', value: 'application/json' });