VALIDATION

TypeScript-first schema validation. Define schemas once, get static types and runtime validation. The default validator for tRPC, Next.js server actions, and AI SDKs.

The most widely used data validation library for Python, and the de facto standard. Type-hint-driven models, fast Rust-based core (v2), and the foundation of FastAPI, LangChain, and most Python AI tooling.

Structured data extraction from any LLM using Pydantic models. Automatic retries, validation, and streaming. 3M+ monthly downloads. Available in Python, TypeScript, Go, Ruby, and Rust.