I agree Codable is one of the worst ways of dealing with JSON apart from manually parsing through dictionaries. I mean It Just Works on a very clean and consistent API, but if people started to mix snake_case with PascalCase, return "1" or any other garbage shit people write when they only thing they have to care about it JS clients then you're typing a lot of unreadable boilerplate.

Since we have custom attributes I will investigate soon if there's a nice framework around that can make it work a bit like the usual JSON libraries in for example C# work.