To whoever does that, I hope that there is a special place in hell where they force you to do type safe API bindings for a JSON API, and every time you use the wrong type for a value, they cave your skull in.
json doesn't have ints, it has Numbers, which are ieee754 floats. if you want to precisely store the full range of a 64 bit int (anything larger than 2^53 -1) then string is indeed the correct type