Python's Flask, along with Flask's Restplus package, can create an API program really quickly. This is all it takes to define a new endpoint, and it will also translate the python dictionary into a proper JSON return value in this GET command:

@ns.route('/health')
@ns.response(404, "Case not found")
class Health(Resource):
    def get(self):
        """Return healthy ping"""
        outstruct = {'id': 0, 'field1': "X3544", 'field2': "X4555", 'disease': 'Z4999', 
                     'subfields': {'subfield1': "Y2333", 'subfield2': "Y8373"}
                    }
        return outstruct