Pydantic

Health v2 · maintenance only

Adoption not part of the score

28626 stars · 2901 forks observed · 2026-08-28

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

Pydantic is the most widely used data validation library for Python, defining schemas via type hints and validating, parsing, and serializing data with a Rust-powered core (pydantic-core). It also emits JSON Schema and supports strict/lax validation modes, dataclasses, and TypedDicts.

Use cases

• validate api request payloads against python type hints
• parse untrusted json into typed models
• generate json schema from python classes
• serialize and deserialize dataclasses and typeddicts
• validate settings and environment configuration
• coerce string data into typed fields with lax mode
• enforce field constraints with annotated types

When to choose

• you want schema validation driven by python type hints with ide and mypy integration
• you need fast validation - the core is written in rust
• you're building fastapi, sqlmodel, or langchain apps where pydantic is the standard
• you need json schema output for tool integration
• you want both strict and coercive (lax) validation modes

When to avoid

• you need validation in a non-python language
• you're on python 3.8 or older
• you want zero compiled dependencies - pydantic-core ships rust binaries
• you're migrating a large v1 codebase without time to handle v2 breaking changes

Facets

library · maturity stable

serialization parser json data-science developer-tools apis web-development python cross-platform data-validation type-hints json-schema pydantic-core rust fastapi-ecosystem schema-validation parsing data-engineering

Member repositories

For agents

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