arktype-validation

ArkType is a TypeScript-native runtime validation library that defines schemas using string expressions mirroring TypeScript syntax, providing editor autocomplete, syntax highlighting, and optimized validators. Use when building type-safe APIs, validating JSON payloads, or replacing Zod with a more TypeScript-idiomatic approach. Not suitable for projects that need Zod ecosystem compatibility or JSON Schema output.

| type({ key: "string" }) | Define object schema | | type("string") | Primitive type | | "string.email", "string.url" | Built-in string validators | | "string.trim", "string.lower" | Built-in string morphs (transforms) | | "string.json.parse" | Parse JSON string to validated object | | "number > 0", "string >= 1" | Inline constraints |

| "string \| number" | Union types | | "'a' \| 'b' \| 'c'" | String literal unions | | "string[]" | Array types | | "key?": "string" | Optional properties | | "key = 'default'" | Default values | | .pipe(), .to() | Transform output (morphs) | | .narrow() | Custom validation (like Zod refine) | | .pick(), .omit() | Object property selection |