It's not very clear what your problem with serialization and deserialization is. Most web frameworks would not treat URL query parameters as a JSON object, but rather treat each key separately and allow you to access the query string as a dictionary (or as arguments to the request handler, depending on framework). Something like request.query['name']. JSON usually appears as the payload for POST, PUT, PATCH and as the response of the request. Even in that case, you get it as a string and do something like json.loads to obtain Python data structures, which you're then free to validate with a json-schema or avro validator library.

The API to validate a schema itself is SomeValidator.check_schema.

Please let me know (by filing an issue) if there's anything in the documentation that would have helped you find it easier!