Seal

Standalone — usable in any Node project, no @warlock.js/core required.

Seal is a schema-first validation library for TypeScript. You declare a shape once with the v factory, and that one declaration gives you:

• A runtime validator (validate(schema, data)) that returns a typed result instead of throwing.
• A static type via Infer<typeof schema> — no hand-rolled parallel type User = { ... }.
• A JSON Schema export (schema.toJsonSchema(target)) for OpenAI structured outputs, OpenAPI specs, AJV, or any other consumer.
• A Standard Schema bridge (schema["~standard"]) so it slots into TanStack Form, Conform, LangGraph, and anything else built against the Standard Schema spec.

import { v, validate, type Infer } from "@warlock.js/seal";

const userSchema = v.object({
  email: v.string().email(),
  age: v.int().min(13).optional(),
  role: v.literal("admin", "user", "guest"),
});

type User = Infer<typeof userSchema>;
// { email: string; age?: number; role: "admin" | "user" | "guest" }

const result = await validate(userSchema, request.body);

if (result.isValid) {
  result.data;  // typed as User
} else {
  result.errors;  // [{ type, error, input }, ...]
}

That single import block is the entire surface area you need for 90% of real apps.

Where to go next

• New here? Start with Introduction and walk the three-page getting-started.
• Coming from Zod / Valibot / Yup? Introduction opens with the comparison frame.
• Already shipping? Essentials is the daily reference; Guides covers task-shaped how-tos.
• Need a specific recipe? Recipes — validate a request body, reuse/compose schemas, coerce query params, custom error messages, optional fields, polymorphic data, recursion, ID validation.
• API surface? Reference / API — every export with signature and one example.

What’s covered here

Section	When to reach for it
Getting started	Install + first schema in 5 minutes.
Essentials	Concepts every user needs — primitives, modifiers, structural shapes, inference, errors.
Guides	Task-oriented how-tos — picking primitives, JSON Schema export, plugins, Standard Schema interop.
Recipes	Copy-paste patterns — request-body validation, schema reuse, query-param coercion, custom messages, optional/default/catch, polymorphic data, recursion, ID formats.
Reference	API surface — one page, every exported identifier.