shortJSON is for when you just need a simple JSON parser for your project and not a monster with thousands of lines of code and/or spread across so many files you'll never be able to understand it.
It's neither optimized for speed or binary size but instead for brevity by using C++17 STL features. In total it's about 300 lines comes in Strict and Tolerant flavors. Strict should be conformant to JSON while Tolerant will read most anything valid in EMCAScript.
Note: comments are completely unsupported and will cause it to throw a const char* error message.
Feel free to use shortJSON in your project without attribution. Just copy shortjson.h and shortjson_xxxxxxx.cpp into your source directory.