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.

Python's de facto data validation library. 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.