Advanced TypeScript runtime reflection system

API input validators with user-friendly error output and TypeScript to ensure you don't miss any properties

complex type validators that generate TypeScript and Flow types for you

AI agent skill for Zod v4 — 27 rules: schema design, parsing, error handling, type inference. Works with Claude Code, Cursor, Codex, Windsurf.

VEffect Validation is a powerful TypeScript validation library built on the robust foundation of Effect, combining exceptional type safety, high performance, and developer experience. Taking inspiration from Effect's functional principles

Reliable runtime type information.

Tiny runtime checker for typing annotations with an Option-like API.

PEP 827 type manipulation library for Python 3.14+. Runtime type evaluation and transformation operators inspired by TypeScript.