Utility-Types is a collection of utility types for TypeScript that complements the language's built-in mapped types and type aliases, functioning as a static-typing equivalent to general-purpose utility libraries.
TypeScript's standard library provides a foundation of mapped types, but developers frequently need additional type utilities for common patterns like union operations, object transformations, and type guards. Utility-Types solves this by offering a curated set of reusable type definitions covering aliases and type guards, union operators, and object operators. The library is designed as pure type-level code with no runtime cost and no external dependencies, making it safe to include in any project without adding bundle size or installation overhead.
Projects that benefit most from this library are those with strict static typing requirements where developers want to avoid rewriting the same type patterns across codebases. It suits teams already comfortable with advanced TypeScript features and those migrating from Flow, since the utility types are designed to be compatible with Flow's type utilities. The library provides both common types that complement TypeScript's built-ins and additional types that ease transitions from Flow-based projects.
The project prioritizes quality through thorough type-correctness testing using dts-jest and maintains a minimal, secure codebase. Work in the issue tracker centers on documentation improvements, funded development through IssueHunt, and openness to community pull requests.
