I supposed if I used some json library I wouldn't have this problem, but it was a simple POST so I didn't bother.
Generating json from scratch is easy. It's parsing json which is a bit more tedious and might justify the use of a library.
In my blog, I use jsmn as a library to parse json in Zorro:
https://www.vitaltrades.com/2019/01...sing-zorro-script-part-2-parse-any-json/You also have the option of loading a json file directly so that you don't have to intermix C and json so much.