github.com/mfcochauxlaberge/jsonapi (go): Package jsonapi offers a library to marshal and unmarshal JSON:API payloads.  It also offers many utilies for developing a JSON:API backend.  The simplest way to start using jsonapi is to use the Marshal and Unmarshal functions.  A schema is collection of types where relationships can point to each other. A schema can also look at its types and return any errors.  A type is generally defined with a struct.  There needs to be an ID field of type string. The `api` tag represents the name of the type.  A lot more is offered in this library. The best way to learn how to use it is to look at the source code and its comments.
Keywords: go|json-api