msgspec/msgspec

Health v2 · maintenance only

Adoption not part of the score

4063 stars · 180 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

msgspec is a fast Python serialization and validation library supporting JSON, MessagePack, YAML, and TOML. It combines high-performance encoders/decoders with zero-cost schema validation using Python type annotations and a speedy Struct type.

Use cases

• fast json parsing in python
• validate api payloads with type annotations
• encode and decode msgpack messages
• replace dataclasses with faster structs
• generate json schema from python types
• parse toml config files
• deserialize yaml into typed objects

When to choose

• you need the fastest JSON or MessagePack encoding/decoding in Python
• you want validation integrated into deserialization with no extra dependencies
• you need a lightweight alternative to pydantic for message schemas
• you're porting from orjson and want validation included

When to avoid

• you need advanced validation features like pydantic's validators or custom constraints
• you're on Python < 3.10
• you need serialization formats beyond JSON, MessagePack, YAML, and TOML

Facets

library · maturity stable

serialization form-handling parser developer-tools apis backend python cross-platform wasm json msgpack yaml toml json-schema type-annotations structs high-performance serde data-engineering

Member repositories

For agents

markdown · JSON · MCP: product_card(name="msgspec/msgspec")