check-compiler

A TypeScript-first schema rule compiler and validation library that compiles declarative rule objects into efficient validation functions. Current stable version is 1.4.0 (released 2023). It has zero dependencies, supports both Node.js (>=16) and browsers, and is very small (minified+gzipped). Unlike runtime validation libraries like zod or yup, check-compiler provides a compiled check function for each schema, making repeated validation fast. It uses a type-driven rule definition with custom messages and supports nested objects, nullable values, and pattern validation. Ships TypeScript types.