ArkType

ArkType is a runtime validation library for TypeScript that uses a syntax-first approach—definitions look exactly like TypeScript code. Unlike builder-pattern libraries (Zod, Yup), ArkType JIT-compiles schemas into optimized validators, achieving 10x-100x performance improvements.

Core Principles

• Write TypeScript syntax, not builder chains - "string >= 8" instead of .string().min(8)
• Zero drift between static and runtime types - Automatic type inference from definitions
• JIT compilation for performance - Schemas compile to optimized JavaScript functions
• Native recursion support - Use Scopes for circular references without lazy() wrappers
• Transform during validation - Morphs allow data transformation in the validation pipeline
• Standard Schema compliant - Works with React Hook Form, TanStack Query, tRPC, and other modern libraries
• Type-level performance matters - Track both runtime speed AND TypeScript compiler instantiations
• String definitions for simple types - Use type("string") for primitives
• Object definitions for structures - Use type({ name: "string" }) for objects
• Scopes for complex models - Use scope({ ... }) for interconnected types

Quick Reference