msgspec is a fast serialization and validation library, with builtin support for
JSON, MessagePack, YAML, and TOML. It features:
- High performance encoders/decoders for common protocols. The JSON and
 MessagePack implementations regularly benchmark as the fastest options for
  Python.
- Support for a wide variety of Python types. Additional types may be supported
  through extensions.
- Zero-cost schema validation using familiar Python type annotations. In
  benchmarks msgspec decodes and validates JSON faster than orjson can decode it
  alone.
- A speedy Struct type for representing structured data. If you already use
  dataclasses or attrs, structs should feel familiar. However, they're 5-60x
  faster for common operations.

All of this is included in a lightweight library with no required dependencies.