JSON parameter need to be an valid JSON [item 0]

Hey @bmax911

I hit the same problem with JSON within JSON - check out this article for a workaround as it worked great for me:

How to pass json inside a json property - Questions - n8n Community

Short version: you need to construct the whole JSON body as an expression within {{ }} brackets, as part of the HTTP Request node configuration.

Hope that helps you. It saved my bacon !