Sinclair TypeBox
Json Schema Type Builder with Static Type Resolution for TypeScript
Install
For the latest version use TypeBox 1.x
$ npm install @sinclair/typebox # TypeBox 0.x - Long Term Support
$ npm install typebox # TypeBox 1.x - LatestExample
import { Type, type Static } from '@sinclair/typebox'
const T = Type.Object({ // const T = {
x: Type.Number(), // type: 'object',
y: Type.Number(), // required: ['x', 'y', 'z'],
z: Type.Number() // properties: {
}) // x: { type: 'number' },
// y: { type: 'number' },
// z: { type: 'number' }
// }
// }
type T = Static<typeof T> // type T = {
// x: number,
// y: number,
// z: number
// }Overview
TypeBox is a runtime type builder that creates in-memory Json Schema objects that infer as TypeScript types. The schematics produced by this library are designed to match the static type checking rules of the TypeScript compiler. TypeBox offers a unified type that can be statically checked by TypeScript and runtime asserted using standard Json Schema validation.
This library is designed to allow Json Schema to compose similar to how types compose within TypeScript's type system. It can be used as a simple tool to build up complex schematics or integrated into REST and RPC services to help validate data received over the wire.
License MIT
Contents
- Install
- Overview
- Usage
- Types
- Values
- Syntax
- TypeRegistry
- TypeCheck
- TypeMap
- TypeSystem
- Error Function
- Workbench
- Codegen
- Ecosystem
- Benchmark
- Contribute
Usage
The following shows general usage.
import { Type, type Static } from '@sinclair/typebox'
//--------------------------------------------------------------------------------------------
//
// Let's say you have the following type ...
//
//--------------------------------------------------------------------------------------------
type T = {
id: string,
name: string,
timestamp: number
}
//--------------------------------------------------------------------------------------------
//
// ... you can express this type in the following way.
//
//--------------------------------------------------------------------------------------------
const T = Type.Object({ // const T = {
id: Type.String(), // type: 'object',
name: Type.String(), // properties: {
timestamp: Type.Integer() // id: {
}) // type: 'string'
// },
// name: {
// type: 'string'
// },
// timestamp: {
// type: 'integer'
// }
// },
// required: [
// 'id',
// 'name',
// 'timestamp'
// ]
// }
//--------------------------------------------------------------------------------------------
//
// ... then infer back to the original static type this way.
//
//--------------------------------------------------------------------------------------------
type T = Static<typeof T> // type T = {
// id: string,
// name: string,
// timestamp: number
// }
//--------------------------------------------------------------------------------------------
//
// ... or use the type to parse JavaScript values.
//
//--------------------------------------------------------------------------------------------
import { Value } from '@sinclair/typebox/value'
const R = Value.Parse(T, value) // const R: {
// id: string,
// name: string,
// timestamp: number
// }Types
TypeBox types are Json Schema fragments that compose into more complex types. Each fragment is structured such that any Json Schema compliant validator can runtime assert a value the same way TypeScript will statically assert a type. TypeBox offers a set of Json Types which are used to create Json Schema compliant schematics as well as a JavaScript type set used to create schematics for constructs native to JavaScript.
Json Types
The following table lists the supported Json types. These types are fully compatible with the Json Schema Draft 7 specification.
┌────────────────────────────────┬─────────────────────────────┬────────────────────────────────┐
│ TypeBox │ TypeScript │ Json Schema │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Any() │ type T = any │ const T = { } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Unknown() │ type T = unknown │ const T = { } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.String() │ type T = string │ const T = { │
│ │ │ type: 'string' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Number() │ type T = number │ const T = { │
│ │ │ type: 'number' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Integer() │ type T = number │ const T = { │
│ │ │ type: 'integer' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Boolean() │ type T = boolean │ const T = { │
│ │ │ type: 'boolean' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Null() │ type T = null │ const T = { │
│ │ │ type: 'null' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Literal(42) │ type T = 42 │ const T = { │
│ │ │ const: 42, │
│ │ │ type: 'number' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Array( │ type T = number[] │ const T = { │
│ Type.Number() │ │ type: 'array', │
│ ) │ │ items: { │
│ │ │ type: 'number' │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Object({ │ type T = { │ const T = { │
│ x: Type.Number(), │ x: number, │ type: 'object', │
│ y: Type.Number() │ y: number │ required: ['x', 'y'], │
│ }) │ } │ properties: { │
│ │ │ x: { │
│ │ │ type: 'number' │
│ │ │ }, │
│ │ │ y: { │
│ │ │ type: 'number' │
│ │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Tuple([ │ type T = [number, number] │ const T = { │
│ Type.Number(), │ │ type: 'array', │
│ Type.Number() │ │ items: [{ │
│ ]) │ │ type: 'number' │
│ │ │ }, { │
│ │ │ type: 'number' │
│ │ │ }], │
│ │ │ additionalItems: false, │
│ │ │ minItems: 2, │
│ │ │ maxItems: 2 │
│ │ │ } │
│ │ │ │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ enum Foo { │ enum Foo { │ const T = { │
│ A, │ A, │ anyOf: [{ │
│ B │ B │ type: 'number', │
│ } │ } │ const: 0 │
│ │ │ }, { │
│ const T = Type.Enum(Foo) │ type T = Foo │ type: 'number', │
│ │ │ const: 1 │
│ │ │ }] │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Const({ │ type T = { │ const T = { │
│ x: 1, │ readonly x: 1, │ type: 'object', │
│ y: 2, │ readonly y: 2 │ required: ['x', 'y'], │
│ } as const) │ } │ properties: { │
│ │ │ x: { │
│ │ │ type: 'number', │
│ │ │ const: 1 │
│ │ │ }, │
│ │ │ y: { │
│ │ │ type: 'number', │
│ │ │ const: 2 │
│ │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.KeyOf( │ type T = keyof { │ const T = { │
│ Type.Object({ │ x: number, │ anyOf: [{ │
│ x: Type.Number(), │ y: number │ type: 'string', │
│ y: Type.Number() │ } │ const: 'x' │
│ }) │ │ }, { │
│ ) │ │ type: 'string', │
│ │ │ const: 'y' │
│ │ │ }] │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Union([ │ type T = string | number │ const T = { │
│ Type.String(), │ │ anyOf: [{ │
│ Type.Number() │ │ type: 'string' │
│ ]) │ │ }, { │
│ │ │ type: 'number' │
│ │ │ }] │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Intersect([ │ type T = { │ const T = { │
│ Type.Object({ │ x: number │ allOf: [{ │
│ x: Type.Number() │ } & { │ type: 'object', │
│ }), │ y: number │ required: ['x'], │
│ Type.Object({ │ } │ properties: { │
│ y: Type.Number() │ │ x: { │
│ }) │ │ type: 'number' │
│ ]) │ │ } │
│ │ │ } │
│ │ │ }, { │
│ │ │ type: 'object', |
│ │ │ required: ['y'], │
│ │ │ properties: { │
│ │ │ y: { │
│ │ │ type: 'number' │
│ │ │ } │
│ │ │ } │
│ │ │ }] │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Composite([ │ type T = { │ const T = { │
│ Type.Object({ │ x: number, │ type: 'object', │
│ x: Type.Number() │ y: number │ required: ['x', 'y'], │
│ }), │ } │ properties: { │
│ Type.Object({ │ │ x: { │
│ y: Type.Number() │ │ type: 'number' │
│ }) │ │ }, │
│ ]) │ │ y: { │
│ │ │ type: 'number' │
│ │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Never() │ type T = never │ const T = { │
│ │ │ not: {} │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Not( | type T = unknown │ const T = { │
│ Type.String() │ │ not: { │
│ ) │ │ type: 'string' │
│ │ │ } │
│ │ │ } │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Extends( │ type T = │ const T = { │
│ Type.String(), │ string extends number │ const: false, │
│ Type.Number(), │ ? true │ type: 'boolean' │
│ Type.Literal(true), │ : false │ } │
│ Type.Literal(false) │ │ │
│ ) │ │ │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Extract( │ type T = Extract< │ const T = { │
│ Type.Union([ │ string | number, │ type: 'string' │
│ Type.String(), │ string │ } │
│ Type.Number(), │ > │ │
│ ]), │ │ │
│ Type.String() │ │ │
│ ) │ │ │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Exclude( │ type T = Exclude< │ const T = { │
│ Type.Union([ │ string | number, │ type: 'number' │
│ Type.String(), │ string │ } │
│ Type.Number(), │ > │ │
│ ]), │ │ │
│ Type.String() │ │ │
│ ) │ │ │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Mapped( │ type T = { │ const T = { │
│ Type.Union([ │ [_ in 'x' | 'y'] : number │ type: 'object', │
│ Type.Literal('x'), │ } │ required: ['x', 'y'], │
│ Type.Literal('y') │ │ properties: { │
│ ]), │ │ x: { │
│ () => Type.Number() │ │ type: 'number' │
│ ) │ │ }, │
│ │ │ y: { │
│ │ │ type: 'number' │
│ │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const U = Type.Union([ │ type U = 'open' | 'close' │ const T = { │
│ Type.Literal('open'), │ │ type: 'string', │
│ Type.Literal('close') │ type T = `on${U}` │ pattern: '^on(open|close)
JavaScript Types
TypeBox provides an extended type set that can be used to create schematics for common JavaScript constructs. These types can not be used with any standard Json Schema validator; but can be used to frame schematics for interfaces that may receive Json validated data. JavaScript types are prefixed with the [JavaScript] JSDoc comment for convenience. The following table lists the supported types.
┌────────────────────────────────┬─────────────────────────────┬────────────────────────────────┐
│ TypeBox │ TypeScript │ Extended Schema │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Constructor([ │ type T = new ( │ const T = { │
│ Type.String(), │ arg0: string, │ type: 'Constructor', │
│ Type.Number() │ arg0: number │ parameters: [{ │
│ ], Type.Boolean()) │ ) => boolean │ type: 'string' │
│ │ │ }, { │
│ │ │ type: 'number' │
│ │ │ }], │
│ │ │ returns: { │
│ │ │ type: 'boolean' │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Function([ │ type T = ( │ const T = { │
| Type.String(), │ arg0: string, │ type: 'Function', │
│ Type.Number() │ arg1: number │ parameters: [{ │
│ ], Type.Boolean()) │ ) => boolean │ type: 'string' │
│ │ │ }, { │
│ │ │ type: 'number' │
│ │ │ }], │
│ │ │ returns: { │
│ │ │ type: 'boolean' │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Promise( │ type T = Promise<string> │ const T = { │
│ Type.String() │ │ type: 'Promise', │
│ ) │ │ item: { │
│ │ │ type: 'string' │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = │ type T = │ const T = { │
│ Type.AsyncIterator( │ AsyncIterableIterator< │ type: 'AsyncIterator', │
│ Type.String() │ string │ items: { │
│ ) │ > │ type: 'string' │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Iterator( │ type T = │ const T = { │
│ Type.String() │ IterableIterator<string> │ type: 'Iterator', │
│ ) │ │ items: { │
│ │ │ type: 'string' │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.RegExp(/abc/i) │ type T = string │ const T = { │
│ │ │ type: 'RegExp' │
│ │ │ source: 'abc' │
│ │ │ flags: 'i' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Uint8Array() │ type T = Uint8Array │ const T = { │
│ │ │ type: 'Uint8Array' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Date() │ type T = Date │ const T = { │
│ │ │ type: 'Date' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Undefined() │ type T = undefined │ const T = { │
│ │ │ type: 'undefined' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Symbol() │ type T = symbol │ const T = { │
│ │ │ type: 'symbol' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.BigInt() │ type T = bigint │ const T = { │
│ │ │ type: 'bigint' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Void() │ type T = void │ const T = { │
│ │ │ type: 'void' │
│ │ │ } │
│ │ │ │
└────────────────────────────────┴─────────────────────────────┴────────────────────────────────┘
Options
You can pass Json Schema options on the last argument of any given type. Option hints specific to each type are provided for convenience.
// String must be an email
const T = Type.String({ // const T = {
format: 'email' // type: 'string',
}) // format: 'email'
// }
// Number must be a multiple of 2
const T = Type.Number({ // const T = {
multipleOf: 2 // type: 'number',
}) // multipleOf: 2
// }
// Array must have at least 5 integer values
const T = Type.Array(Type.Integer(), { // const T = {
minItems: 5 // type: 'array',
}) // minItems: 5,
// items: {
// type: 'integer'
// }
// }
Properties
Object properties can be modified with Readonly and Optional. The following table shows how these modifiers map between TypeScript and Json Schema.
┌────────────────────────────────┬─────────────────────────────┬────────────────────────────────┐
│ TypeBox │ TypeScript │ Json Schema │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Object({ │ type T = { │ const T = { │
│ name: Type.ReadonlyOptional( │ readonly name?: string │ type: 'object', │
│ Type.String() │ } │ properties: { │
│ ) │ │ name: { │
│ }) │ │ type: 'string' │
│ │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Object({ │ type T = { │ const T = { │
│ name: Type.Readonly( │ readonly name: string │ type: 'object', │
│ Type.String() │ } │ properties: { │
│ ) │ │ name: { │
│ }) │ │ type: 'string' │
│ │ │ } │
│ │ │ }, │
│ │ │ required: ['name'] │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Object({ │ type T = { │ const T = { │
│ name: Type.Optional( │ name?: string │ type: 'object', │
│ Type.String() │ } │ properties: { │
│ ) │ │ name: { │
│ }) │ │ type: 'string' │
│ │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
└────────────────────────────────┴─────────────────────────────┴────────────────────────────────┘
Generic Types
Generic types can be created with generic functions.
const Nullable = <T extends TSchema>(T: T) => { // type Nullable<T> = T | null
return Type.Union([T, Type.Null()])
}
const T = Nullable(Type.String()) // type T = Nullable<string>
Recursive Types
Use the Recursive function to create recursive types.
const Node = Type.Recursive(This => Type.Object({ // const Node = {
id: Type.String(), // $id: 'Node',
nodes: Type.Array(This) // type: 'object',
}), { $id: 'Node' }) // properties: {
// id: {
// type: 'string'
// },
// nodes: {
// type: 'array',
// items: {
// $ref: 'Node'
// }
// }
// },
// required: [
// 'id',
// 'nodes'
// ]
// }
type Node = Static<typeof Node> // type Node = {
// id: string
// nodes: Node[]
// }
function test(node: Node) {
const id = node.nodes[0].nodes[0].id // id is string
}
Module Types
Module types are containers for a set of referential types. Modules act as namespaces, enabling types to reference one another via string identifiers. Modules support both singular and mutually recursive references, as well as deferred dereferencing for computed types such as Partial. Types imported from a module are expressed using the Json Schema $defs keyword.
const Module = Type.Module({
PartialUser: Type.Partial(Type.Ref('User')), // TComputed<'Partial', [TRef<'User'>]>
User: Type.Object({ // TObject<{
id: Type.String(), // user: TString,
name: Type.String(), // name: TString,
email: Type.String() // email: TString
}), // }>
})
const User = Module.Import('User') // const User: TImport<{...}, 'User'>
type User = Static<typeof User> // type User = {
// id: string,
// name: string,
// email: string
// }
const PartialUser = Module.Import('PartialUser') // const PartialUser: TImport<{...}, 'PartialUser'>
type PartialUser = Static<typeof PartialUser> // type PartialUser = {
// id?: string,
// name?: string,
// email?: string
// }
Template Literal Types
TypeBox supports template literal types with the TemplateLiteral function. This type can be created using a syntax similar to the TypeScript template literal syntax or composed from exterior types. TypeBox encodes template literals as regular expressions which enables the template to be checked by Json Schema validators. This type also supports regular expression parsing that enables template patterns to be used for generative types. The following shows both TypeScript and TypeBox usage.
// TypeScript
type K = `prop${'A'|'B'|'C'}` // type T = 'propA' | 'propB' | 'propC'
type R = Record<K, string> // type R = {
// propA: string
// propB: string
// propC: string
// }
// TypeBox
const K = Type.TemplateLiteral('prop${A|B|C}') // const K: TTemplateLiteral<[
// TLiteral<'prop'>,
// TUnion<[
// TLiteral<'A'>,
// TLiteral<'B'>,
// TLiteral<'C'>,
// ]>
// ]>
const R = Type.Record(K, Type.String()) // const R: TObject<{
// propA: TString,
// propB: TString,
// propC: TString,
// }>
Indexed Access Types
TypeBox supports indexed access types with the Index function. This function enables uniform access to interior property and element types without having to extract them from the underlying schema representation. Index types are supported for Object, Array, Tuple, Union and Intersect types.
const T = Type.Object({ // type T = {
x: Type.Number(), // x: number,
y: Type.String(), // y: string,
z: Type.Boolean() // z: boolean
}) // }
const A = Type.Index(T, ['x']) // type A = T['x']
//
// ... evaluated as
//
// const A: TNumber
const B = Type.Index(T, ['x', 'y']) // type B = T['x' | 'y']
//
// ... evaluated as
//
// const B: TUnion<[
// TNumber,
// TString,
// ]>
const C = Type.Index(T, Type.KeyOf(T)) // type C = T[keyof T]
//
// ... evaluated as
//
// const C: TUnion<[
// TNumber,
// TString,
// TBoolean
// ]>
Mapped Types
TypeBox supports mapped types with the Mapped function. This function accepts two arguments, the first is a union type typically derived from KeyOf, the second is a mapping function that receives a mapping key K that can be used to index properties of a type. The following implements a mapped type that remaps each property to be T | null.
const T = Type.Object({ // type T = {
x: Type.Number(), // x: number,
y: Type.String(), // y: string,
z: Type.Boolean() // z: boolean
}) // }
const M = Type.Mapped(Type.KeyOf(T), K => { // type M = { [K in keyof T]: T[K] | null }
return Type.Union([Type.Index(T, K), Type.Null()]) //
}) // ... evaluated as
//
// const M: TObject<{
// x: TUnion<[TNumber, TNull]>,
// y: TUnion<[TString, TNull]>,
// z: TUnion<[TBoolean, TNull]>
// }>
Conditional Types
TypeBox supports runtime conditional types with the Extends function. This function performs a structural assignability check against the first (left) and second (right) arguments and will return either the third (true) or fourth (false) argument based on the result. The conditional types Exclude and Extract are also supported. The following shows both TypeScript and TypeBox examples of conditional types.
// Extends
const A = Type.Extends( // type A = string extends number ? 1 : 2
Type.String(), //
Type.Number(), // ... evaluated as
Type.Literal(1), //
Type.Literal(2) // const A: TLiteral<2>
)
// Extract
const B = Type.Extract( // type B = Extract<1 | 2 | 3, 1>
Type.Union([ //
Type.Literal(1), // ... evaluated as
Type.Literal(2), //
Type.Literal(3) // const B: TLiteral<1>
]),
Type.Literal(1)
)
// Exclude
const C = Type.Exclude( // type C = Exclude<1 | 2 | 3, 1>
Type.Union([ //
Type.Literal(1), // ... evaluated as
Type.Literal(2), //
Type.Literal(3) // const C: TUnion<[
]), // TLiteral<2>,
Type.Literal(1) // TLiteral<3>,
) // ]>
Transform Types
TypeBox supports value decoding and encoding with Transform types. These types work in tandem with the Encode and Decode functions available on the Value and TypeCompiler submodules. Transform types can be used to convert Json encoded values into constructs more natural to JavaScript. The following creates a Transform type to decode numbers into Dates using the Value submodule.
import { Value } from '@sinclair/typebox/value'
const T = Type.Transform(Type.Number())
.Decode(value => new Date(value)) // decode: number to Date
.Encode(value => value.getTime()) // encode: Date to number
const D = Value.Decode(T, 0) // const D = Date(1970-01-01T00:00:00.000Z)
const E = Value.Encode(T, D) // const E = 0
Use the StaticEncode or StaticDecode types to infer a Transform type.
import { Static, StaticDecode, StaticEncode } from '@sinclair/typebox'
const T = Type.Transform(Type.Array(Type.Number(), { uniqueItems: true }))
.Decode(value => new Set(value))
.Encode(value => [...value])
type D = StaticDecode<typeof T> // type D = Set<number>
type E = StaticEncode<typeof T> // type E = Array<number>
type T = Static<typeof T> // type T = Array<number>
Unsafe Types
TypeBox supports user defined types with Unsafe. This type allows you to specify both schema representation and inference type. The following creates an Unsafe type with a number schema that infers as string.
const T = Type.Unsafe<string>({ type: 'number' }) // const T = { type: 'number' }
type T = Static<typeof T> // type T = string - ?
The Unsafe type is often used to create schematics for extended specifications like OpenAPI.
const Nullable = <T extends TSchema>(schema: T) => Type.Unsafe<Static<T> | null>({
...schema, nullable: true
})
const T = Nullable(Type.String()) // const T = {
// type: 'string',
// nullable: true
// }
type T = Static<typeof T> // type T = string | null
const StringEnum = <T extends string[]>(values: [...T]) => Type.Unsafe<T[number]>({
type: 'string', enum: values
})
const S = StringEnum(['A', 'B', 'C']) // const S = {
// enum: ['A', 'B', 'C']
// }
type S = Static<typeof T> // type S = 'A' | 'B' | 'C'
TypeGuard
TypeBox can check its own types with the TypeGuard module. This module is written for type introspection and provides structural tests for every built-in TypeBox type. Functions of this module return is guards which can be used with control flow assertions to obtain schema inference for unknown values. The following guards that the value T is TString.
import { TypeGuard, Kind } from '@sinclair/typebox'
const T = { [Kind]: 'String', type: 'string' }
if(TypeGuard.IsString(T)) {
// T is TString
}
Values
TypeBox provides an optional Value submodule that can be used to perform structural operations on JavaScript values. This submodule includes functionality to create, check and cast values from types as well as check equality, clone, diff and patch JavaScript values. This submodule is provided via optional import.
import { Value } from '@sinclair/typebox/value'
Assert
Use the Assert function to assert a value is valid.
let value: unknown = 1
Value.Assert(Type.Number(), value) // throws AssertError if invalid
Create
Use the Create function to create a value from a type. TypeBox will use default values if specified.
const T = Type.Object({ x: Type.Number(), y: Type.Number({ default: 42 }) })
const A = Value.Create(T) // const A = { x: 0, y: 42 }
Clone
Use the Clone function to deeply clone a value.
const A = Value.Clone({ x: 1, y: 2, z: 3 }) // const A = { x: 1, y: 2, z: 3 }
Check
Use the Check function to type check a value.
const T = Type.Object({ x: Type.Number() })
const R = Value.Check(T, { x: 1 }) // const R = true
Convert
Use the Convert function to convert a value into its target type if a reasonable conversion is possible. This function may return an invalid value and should be checked before use. Its return type is unknown.
const T = Type.Object({ x: Type.Number() })
const R1 = Value.Convert(T, { x: '3.14' }) // const R1 = { x: 3.14 }
const R2 = Value.Convert(T, { x: 'not a number' }) // const R2 = { x: 'not a number' }
Clean
Use Clean to remove excess properties from a value. This function does not check the value and returns an unknown type. You should Check the result before use. Clean is a mutable operation. To avoid mutation, Clone the value first.
const T = Type.Object({
x: Type.Number(),
y: Type.Number()
})
const X = Value.Clean(T, null) // const 'X = null
const Y = Value.Clean(T, { x: 1 }) // const 'Y = { x: 1 }
const Z = Value.Clean(T, { x: 1, y: 2, z: 3 }) // const 'Z = { x: 1, y: 2 }
Default
Use Default to generate missing properties on a value using default schema annotations if available. This function does not check the value and returns an unknown type. You should Check the result before use. Default is a mutable operation. To avoid mutation, Clone the value first.
const T = Type.Object({
x: Type.Number({ default: 0 }),
y: Type.Number({ default: 0 })
})
const X = Value.Default(T, null) // const 'X = null - non-enumerable
const Y = Value.Default(T, { }) // const 'Y = { x: 0, y: 0 }
const Z = Value.Default(T, { x: 1 }) // const 'Z = { x: 1, y: 0 }
Cast
Use the Cast function to upcast a value into a target type. This function will retain as much information as possible from the original value. The Cast function is intended to be used in data migration scenarios where existing values need to be upgraded to match a modified type.
const T = Type.Object({ x: Type.Number(), y: Type.Number() }, { additionalProperties: false })
const X = Value.Cast(T, null) // const X = { x: 0, y: 0 }
const Y = Value.Cast(T, { x: 1 }) // const Y = { x: 1, y: 0 }
const Z = Value.Cast(T, { x: 1, y: 2, z: 3 }) // const Z = { x: 1, y: 2 }
Decode
Use the Decode function to decode a value from a type or throw if the value is invalid. The return value will infer as the decoded type. This function will run Transform codecs if available.
const A = Value.Decode(Type.String(), 'hello') // const A = 'hello'
const B = Value.Decode(Type.String(), 42) // throw
Encode
Use the Encode function to encode a value to a type or throw if the value is invalid. The return value will infer as the encoded type. This function will run Transform codecs if available.
const A = Value.Encode(Type.String(), 'hello') // const A = 'hello'
const B = Value.Encode(Type.String(), 42) // throw
Parse
Use the Parse function to parse a value. This function calls the Clone Clean, Default, Convert, Assert and Decode Value functions in this exact order to process a value.
const R = Value.Parse(Type.String(), 'hello') // const R: string = "hello"
const E = Value.Parse(Type.String(), undefined) // throws AssertError
You can override the order in which functions are run, or omit functions entirely using the following.
// Runs no functions.
const R = Value.Parse([], Type.String(), 12345)
// Runs the Assert() function.
const E = Value.Parse(['Assert'], Type.String(), 12345)
// Runs the Convert() function followed by the Assert() function.
const S = Value.Parse(['Convert', 'Assert'], Type.String(), 12345)
Equal
Use the Equal function to deeply check for value equality.
const R = Value.Equal( // const R = true
{ x: 1, y: 2, z: 3 },
{ x: 1, y: 2, z: 3 }
)
Hash
Use the Hash function to create a FNV1A-64 non-cryptographic hash of a value.
const A = Value.Hash({ x: 1, y: 2, z: 3 }) // const A = 2910466848807138541n
const B = Value.Hash({ x: 1, y: 4, z: 3 }) // const B = 1418369778807423581n
Diff
Use the Diff function to generate a sequence of edits that will transform one value into another.
const E = Value.Diff( // const E = [
{ x: 1, y: 2, z: 3 }, // { type: 'update', path: '/y', value: 4 },
{ y: 4, z: 5, w: 6 } // { type: 'update', path: '/z', value: 5 },
) // { type: 'insert', path: '/w', value: 6 },
// { type: 'delete', path: '/x' }
// ]
Patch
Use the Patch function to apply a sequence of edits.
const A = { x: 1, y: 2 }
const B = { x: 3 }
const E = Value.Diff(A, B) // const E = [
// { type: 'update', path: '/x', value: 3 },
// { type: 'delete', path: '/y' }
// ]
const C = Value.Patch<typeof B>(A, E) // const C = { x: 3 }
Errors
Use the Errors function to enumerate validation errors.
const T = Type.Object({ x: Type.Number(), y: Type.Number() })
const R = [...Value.Errors(T, { x: '42' })] // const R = [{
// schema: { type: 'number' },
// path: '/x',
// value: '42',
// message: 'Expected number'
// }, {
// schema: { type: 'number' },
// path: '/y',
// value: undefined,
// message: 'Expected number'
// }]
Mutate
Use the Mutate function to perform a deep mutable value assignment while retaining internal references.
const Y = { z: 1 } // const Y = { z: 1 }
const X = { y: Y } // const X = { y: { z: 1 } }
const A = { x: X } // const A = { x: { y: { z: 1 } } }
Value.Mutate(A, { x: { y: { z: 2 } } }) // A' = { x: { y: { z: 2 } } }
const R0 = A.x.y.z === 2 // const R0 = true
const R1 = A.x.y === Y // const R1 = true
const R2 = A.x === X // const R2 = true
Pointer
Use ValuePointer to perform mutable updates on existing values using RFC6901 Json Pointers.
import { ValuePointer } from '@sinclair/typebox/value'
const A = { x: 0, y: 0, z: 0 }
ValuePointer.Set(A, '/x', 1) // A' = { x: 1, y: 0, z: 0 }
ValuePointer.Set(A, '/y', 1) // A' = { x: 1, y: 1, z: 0 }
ValuePointer.Set(A, '/z', 1) // A' = { x: 1, y: 1, z: 1 }
Syntax Types
TypeBox provides experimental support for parsing TypeScript annotation syntax into TypeBox types.
This feature is provided via optional import.
import { Syntax } from '@sinclair/typebox/syntax'
Create
Use the Syntax function to create TypeBox types from TypeScript syntax (Example)
const T = Syntax(`{ x: number, y: number }`) // const T: TObject<{
// x: TNumber,
// y: TNumber
// }>
type T = Static<typeof T> // type T = {
// x: number,
// y: number
// }
Parameters
Syntax types can be parameterized to receive exterior types (Example)
const T = Syntax(`{ x: number, y: number }`) // const T: TObject<{
// x: TNumber,
// y: TNumber
// }>
const S = Syntax({ T }, `Partial<T>`) // const S: TObject<{
// x: TOptional<TNumber>,
// y: TOptional<TNumber>
// }>
Generics
Syntax types support generic parameters in the following way (Example)
const Vector = Syntax(`<X, Y, Z> {
x: X,
y: Y,
z: Z
}`)
const BasisVectors = Syntax({ Vector }, `{
x: Vector<1, 0, 0>,
y: Vector<0, 1, 0>,
z: Vector<0, 0, 1>,
}`)
type BasisVectors = Static<typeof BasisVectors> // type BasisVectors = {
// x: { x: 1, y: 0, z: 0 },
// y: { x: 0, y: 1, z: 0 },
// z: { x: 0, y: 0, z: 1 }
// }
Options
Options can be passed via the last parameter.
const T = Syntax(`number`, { minimum: 42 }) // const T = {
// type: 'number',
// minimum: 42
// }
NoInfer
Syntax parsing is an expensive type level operation and can impact on language service performance. Use the NoInfer function parse syntax at runtime only.
import { NoInfer } from '@sinclair/typebox/syntax'
const T = NoInfer(`number | string`) // const T: TSchema = {
// anyOf: [
// { type: 'number' },
// { type: 'string' }
// ]
// }
TypeRegistry
The TypeBox type system can be extended with additional types and formats using the TypeRegistry and FormatRegistry modules. These modules integrate deeply with TypeBox's internal type checking infrastructure and can be used to create application specific types, or register schematics for alternative specifications.
TypeRegistry
Use the TypeRegistry to register a type. The Kind must match the registered type name.
import { TSchema, Kind, TypeRegistry } from '@sinclair/typebox'
TypeRegistry.Set('Foo', (schema, value) => value === 'foo')
const Foo = { [Kind]: 'Foo' } as TSchema
const A = Value.Check(Foo, 'foo') // const A = true
const B = Value.Check(Foo, 'bar') // const B = false
FormatRegistry
Use the FormatRegistry to register a string format.
import { FormatRegistry } from '@sinclair/typebox'
FormatRegistry.Set('foo', (value) => value === 'foo')
const T = Type.String({ format: 'foo' })
const A = Value.Check(T, 'foo') // const A = true
const B = Value.Check(T, 'bar') // const B = false
TypeCheck
TypeBox types target Json Schema Draft 7 and are compatible with any validator that supports this specification. TypeBox also provides a built-in type checking compiler designed specifically for TypeBox types that offers high performance compilation and value checking.
The following sections detail using Ajv and the TypeBox compiler infrastructure.
Ajv
The following shows the recommended setup for Ajv.
$ npm install ajv ajv-formats --save
import { Type } from '@sinclair/typebox'
import addFormats from 'ajv-formats'
import Ajv from 'ajv'
const ajv = addFormats(new Ajv({}), [
'date-time',
'time',
'date',
'email',
'hostname',
'ipv4',
'ipv6',
'uri',
'uri-reference',
'uuid',
'uri-template',
'json-pointer',
'relative-json-pointer',
'regex'
])
const validate = ajv.compile(Type.Object({
x: Type.Number(),
y: Type.Number(),
z: Type.Number()
}))
const R = validate({ x: 1, y: 2, z: 3 }) // const R = true
TypeCompiler
The TypeBox TypeCompiler is a high performance JIT validation compiler that transforms TypeBox types into optimized JavaScript validation routines. The compiler is tuned for fast compilation as well as fast value assertion. It is built to serve as a validation backend that can be integrated into larger applications. It can also be used for code generation.
The TypeCompiler is provided as an optional import.
import { TypeCompiler } from '@sinclair/typebox/compiler'
Use the Compile function to JIT compile a type. Note that compilation is generally an expensive operation and should only be performed once per type during application start up. TypeBox does not cache previously compiled types, and applications are expected to hold references to each compiled type for the lifetime of the application.
const C = TypeCompiler.Compile(Type.Object({ // const C: TypeCheck<TObject<{
x: Type.Number(), // x: TNumber;
y: Type.Number(), // y: TNumber;
z: Type.Number() // z: TNumber;
})) // }>>
const R = C.Check({ x: 1, y: 2, z: 3 }) // const R = true
Use the Errors function to generate diagnostic errors for a value. The Errors function will return an iterator that when enumerated; will perform an exhaustive check across the entire value yielding any error found. For performance, this function should only be called after a failed Check. Applications may also choose to yield only the first value to avoid exhaustive error generation.
const C = TypeCompiler.Compile(Type.Object({ // const C: TypeCheck<TObject<{
x: Type.Number(), // x: TNumber;
y: Type.Number(), // y: TNumber;
z: Type.Number() // z: TNumber;
})) // }>>
const value = { }
const first = C.Errors(value).First() // const first = {
// schema: { type: 'number' },
// path: '/x',
// value: undefined,
// message: 'Expected number'
// }
const all = [...C.Errors(value)] // const all = [{
// schema: { type: 'number' },
// path: '/x',
// value: undefined,
// message: 'Expected number'
// }, {
// schema: { type: 'number' },
// path: '/y',
// value: undefined,
// message: 'Expected number'
// }, {
// schema: { type: 'number' },
// path: '/z',
// value: undefined,
// message: 'Expected number'
// }]
Use the Code function to generate assertion functions as strings. This function can be used to generate code that can be written to disk as importable modules. This technique is sometimes referred to as Ahead of Time (AOT) compilation. The following generates code to check a string.
const C = TypeCompiler.Code(Type.String()) // const C = `return function check(value) {
// return (
// (typeof value === 'string')
// )
// }`
TypeMap
TypeBox offers an external package for bidirectional mapping between TypeBox, Valibot, and Zod type libraries. It also includes syntax parsing support for Valibot and Zod and supports the Standard Schema specification. For more details on TypeMap, refer to the project repository.
Usage
TypeMap needs to be installed separately
$ npm install @sinclair/typemap
Once installed it offers advanced structural remapping between various runtime type libraries (Example)
import { TypeBox, Syntax, Zod } from '@sinclair/typemap'
const T = TypeBox(`{ x: number, y: number, z: number }`) // const T: TObject<{
// x: TNumber;
// y: TNumber;
// z: TNumber;
// }>
const S = Syntax(T) // const S: '{ x: number, y: number, z: number }'
const R = Zod(S).parse(null) // const R: {
// x: number;
// y: number;
// z: number;
// }
TypeSystem
The TypeBox TypeSystem module provides configurations to use either Json Schema or TypeScript type checking semantics. Configurations made to the TypeSystem module are observed by the TypeCompiler, Value and Error modules.
Policies
TypeBox validates using standard Json Schema assertion policies by default. The TypeSystemPolicy module can override some of these to have TypeBox assert values inline with TypeScript static checks. It also provides overrides for certain checking rules related to non-serializable values (such as void) which can be helpful in Json based protocols such as Json Rpc 2.0.
The following overrides are available.
import { TypeSystemPolicy } from '@sinclair/typebox/system'
// Disallow undefined values for optional properties (default is false)
//
// const A: { x?: number } = { x: undefined } - disallowed when enabled
TypeSystemPolicy.ExactOptionalPropertyTypes = true
// Allow arrays to validate as object types (default is false)
//
// const A: {} = [] - allowed in TS
TypeSystemPolicy.AllowArrayObject = true
// Allow numeric values to be NaN or + or - Infinity (default is false)
//
// const A: number = NaN - allowed in TS
TypeSystemPolicy.AllowNaN = true
// Allow void types to check with undefined and null (default is false)
//
// Used to signal void return on Json-Rpc 2.0 protocol
TypeSystemPolicy.AllowNullVoid = true
Error Function
Error messages in TypeBox can be customized by defining an ErrorFunction. This function allows for the localization of error messages as well as enabling custom error messages for custom types. By default, TypeBox will generate messages using the en-US locale. To support additional locales, you can replicate the function found in src/errors/function.ts and create a locale specific translation. The function can then be set via SetErrorFunction.
The following example shows an inline error function that intercepts errors for String, Number and Boolean only. The DefaultErrorFunction is used to return a default error message.
import { SetErrorFunction, DefaultErrorFunction, ValueErrorType } from '@sinclair/typebox/errors'
SetErrorFunction((error) => { // i18n override
switch(error.errorType) {
/* en-US */ case ValueErrorType.String: return 'Expected string'
/* fr-FR */ case ValueErrorType.Number: return 'Nombre attendu'
/* ko-KR */ case ValueErrorType.Boolean: return '예상 부울'
/* en-US */ default: return DefaultErrorFunction(error)
}
})
const T = Type.Object({ // const T: TObject<{
x: Type.String(), // TString,
y: Type.Number(), // TNumber,
z: Type.Boolean() // TBoolean
}) // }>
const E = [...Value.Errors(T, { // const E = [{
x: null, // type: 48,
y: null, // schema: { ... },
z: null // path: '/x',
})] // value: null,
// message: 'Expected string'
// }, {
// type: 34,
// schema: { ... },
// path: '/y',
// value: null,
// message: 'Nombre attendu'
// }, {
// type: 14,
// schema: { ... },
// path: '/z',
// value: null,
// message: '예상 부울'
// }]
TypeBox Workbench
TypeBox offers a web based code generation tool that can convert TypeScript types into TypeBox types as well as several other ecosystem libraries.
TypeBox Codegen
TypeBox provides a code generation library that can be integrated into toolchains to automate type translation between TypeScript and TypeBox. This library also includes functionality to transform TypeScript types to other ecosystem libraries.
Ecosystem
The following is a list of community packages that offer general tooling, extended functionality and framework integration support for TypeBox.
Package
Description
drizzle-typebox
Generates TypeBox types from Drizzle ORM schemas
elysia
Fast and friendly Bun web framework
fastify-type-provider-typebox
Fastify TypeBox integration with the Fastify Type Provider
feathersjs
The API and real-time application framework
fetch-typebox
Drop-in replacement for fetch that brings easy integration with TypeBox
@lonli-lokli/fetcher-typebox
A strongly-typed fetch wrapper for TypeScript applications with optional runtime validation using TypeBox
h3-typebox
Schema validation utilities for h3 using TypeBox & Ajv
http-wizard
Type safe http client library for Fastify
json2typebox
Creating TypeBox code from Json Data
nominal-typebox
Allows devs to integrate nominal types into TypeBox schemas
openapi-box
Generate TypeBox types from OpenApi IDL + Http client library
prismabox
Converts a prisma.schema to TypeBox schema matching the database models
schema2typebox
Creating TypeBox code from Json Schemas
sveltekit-superforms
A comprehensive SvelteKit form library for server and client validation
ts2typebox
Creating TypeBox code from Typescript types
typebox-cli
Generate Schema with TypeBox from the CLI
typebox-form-parser
Parses form and query data based on TypeBox schemas
typebox-schema-faker
Generate fake data from TypeBox schemas for testing, prototyping and development
Benchmark
This project maintains a set of benchmarks that measure Ajv, Value and TypeCompiler compilation and validation performance. These benchmarks can be run locally by cloning this repository and running npm run benchmark. The results below show for Ajv version 8.12.0 running on Node 20.10.0.
For additional comparative benchmarks, please refer to typescript-runtime-type-benchmarks.
Compile
This benchmark measures compilation performance for varying types.
┌────────────────────────────┬────────────┬──────────────┬──────────────┬──────────────┐
│ (index) │ Iterations │ Ajv │ TypeCompiler │ Performance │
├────────────────────────────┼────────────┼──────────────┼──────────────┼──────────────┤
│ Literal_String │ 1000 │ ' 211 ms' │ ' 8 ms' │ ' 26.38 x' │
│ Literal_Number │ 1000 │ ' 185 ms' │ ' 5 ms' │ ' 37.00 x' │
│ Literal_Boolean │ 1000 │ ' 195 ms' │ ' 4 ms' │ ' 48.75 x' │
│ Primitive_Number │ 1000 │ ' 149 ms' │ ' 7 ms' │ ' 21.29 x' │
│ Primitive_String │ 1000 │ ' 135 ms' │ ' 5 ms' │ ' 27.00 x' │
│ Primitive_String_Pattern │ 1000 │ ' 193 ms' │ ' 10 ms' │ ' 19.30 x' │
│ Primitive_Boolean │ 1000 │ ' 152 ms' │ ' 4 ms' │ ' 38.00 x' │
│ Primitive_Null │ 1000 │ ' 147 ms' │ ' 4 ms' │ ' 36.75 x' │
│ Object_Unconstrained │ 1000 │ ' 1065 ms' │ ' 26 ms' │ ' 40.96 x' │
│ Object_Constrained │ 1000 │ ' 1183 ms' │ ' 26 ms' │ ' 45.50 x' │
│ Object_Vector3 │ 1000 │ ' 407 ms' │ ' 9 ms' │ ' 45.22 x' │
│ Object_Box3D │ 1000 │ ' 1777 ms' │ ' 24 ms' │ ' 74.04 x' │
│ Tuple_Primitive │ 1000 │ ' 485 ms' │ ' 11 ms' │ ' 44.09 x' │
│ Tuple_Object │ 1000 │ ' 1344 ms' │ ' 17 ms' │ ' 79.06 x' │
│ Composite_Intersect │ 1000 │ ' 606 ms' │ ' 14 ms' │ ' 43.29 x' │
│ Composite_Union │ 1000 │ ' 522 ms' │ ' 17 ms' │ ' 30.71 x' │
│ Math_Vector4 │ 1000 │ ' 851 ms' │ ' 9 ms' │ ' 94.56 x' │
│ Math_Matrix4 │ 1000 │ ' 406 ms' │ ' 10 ms' │ ' 40.60 x' │
│ Array_Primitive_Number │ 1000 │ ' 367 ms' │ ' 6 ms' │ ' 61.17 x' │
│ Array_Primitive_String │ 1000 │ ' 339 ms' │ ' 7 ms' │ ' 48.43 x' │
│ Array_Primitive_Boolean │ 1000 │ ' 325 ms' │ ' 5 ms' │ ' 65.00 x' │
│ Array_Object_Unconstrained │ 1000 │ ' 1863 ms' │ ' 21 ms' │ ' 88.71 x' │
│ Array_Object_Constrained │ 1000 │ ' 1535 ms' │ ' 18 ms' │ ' 85.28 x' │
│ Array_Tuple_Primitive │ 1000 │ ' 829 ms' │ ' 14 ms' │ ' 59.21 x' │
│ Array_Tuple_Object │ 1000 │ ' 1674 ms' │ ' 14 ms' │ ' 119.57 x' │
│ Array_Composite_Intersect │ 1000 │ ' 789 ms' │ ' 13 ms' │ ' 60.69 x' │
│ Array_Composite_Union │ 1000 │ ' 822 ms' │ ' 15 ms' │ ' 54.80 x' │
│ Array_Math_Vector4 │ 1000 │ ' 1129 ms' │ ' 14 ms' │ ' 80.64 x' │
│ Array_Math_Matrix4 │ 1000 │ ' 673 ms' │ ' 9 ms' │ ' 74.78 x' │
└────────────────────────────┴────────────┴──────────────┴──────────────┴──────────────┘
Validate
This benchmark measures validation performance for varying types.
┌────────────────────────────┬────────────┬──────────────┬──────────────┬──────────────┬──────────────┐
│ (index) │ Iterations │ ValueCheck │ Ajv │ TypeCompiler │ Performance │
├────────────────────────────┼────────────┼──────────────┼──────────────┼──────────────┼──────────────┤
│ Literal_String │ 1000000 │ ' 17 ms' │ ' 5 ms' │ ' 5 ms' │ ' 1.00 x' │
│ Literal_Number │ 1000000 │ ' 14 ms' │ ' 18 ms' │ ' 9 ms' │ ' 2.00 x' │
│ Literal_Boolean │ 1000000 │ ' 14 ms' │ ' 20 ms' │ ' 9 ms' │ ' 2.22 x' │
│ Primitive_Number │ 1000000 │ ' 17 ms' │ ' 19 ms' │ ' 9 ms' │ ' 2.11 x' │
│ Primitive_String │ 1000000 │ ' 17 ms' │ ' 18 ms' │ ' 10 ms' │ ' 1.80 x' │
│ Primitive_String_Pattern │ 1000000 │ ' 172 ms' │ ' 46 ms' │ ' 41 ms' │ ' 1.12 x' │
│ Primitive_Boolean │ 1000000 │ ' 14 ms' │ ' 19 ms' │ ' 10 ms' │ ' 1.90 x' │
│ Primitive_Null │ 1000000 │ ' 16 ms' │ ' 19 ms' │ ' 9 ms' │ ' 2.11 x' │
│ Object_Unconstrained │ 1000000 │ ' 437 ms' │ ' 28 ms' │ ' 14 ms' │ ' 2.00 x' │
│ Object_Constrained │ 1000000 │ ' 653 ms' │ ' 46 ms' │ ' 37 ms' │ ' 1.24 x' │
│ Object_Vector3 │ 1000000 │ ' 201 ms' │ ' 22 ms' │ ' 12 ms' │ ' 1.83 x' │
│ Object_Box3D │ 1000000 │ ' 961 ms' │ ' 37 ms' │ ' 19 ms' │ ' 1.95 x' │
│ Object_Recursive │ 1000000 │ ' 3715 ms' │ ' 363 ms' │ ' 174 ms' │ ' 2.09 x' │
│ Tuple_Primitive │ 1000000 │ ' 107 ms' │ ' 23 ms' │ ' 11 ms' │ ' 2.09 x' │
│ Tuple_Object │ 1000000 │ ' 375 ms' │ ' 28 ms' │ ' 15 ms' │ ' 1.87 x' │
│ Composite_Intersect │ 1000000 │ ' 377 ms' │ ' 22 ms' │ ' 12 ms' │ ' 1.83 x' │
│ Composite_Union │ 1000000 │ ' 337 ms' │ ' 30 ms' │ ' 17 ms' │ ' 1.76 x' │
│ Math_Vector4 │ 1000000 │ ' 137 ms' │ ' 23 ms' │ ' 11 ms' │ ' 2.09 x' │
│ Math_Matrix4 │ 1000000 │ ' 576 ms' │ ' 37 ms' │ ' 28 ms' │ ' 1.32 x' │
│ Array_Primitive_Number │ 1000000 │ ' 145 ms' │ ' 23 ms' │ ' 12 ms' │ ' 1.92 x' │
│ Array_Primitive_String │ 1000000 │ ' 152 ms' │ ' 22 ms' │ ' 13 ms' │ ' 1.69 x' │
│ Array_Primitive_Boolean │ 1000000 │ ' 131 ms' │ ' 20 ms' │ ' 13 ms' │ ' 1.54 x' │
│ Array_Object_Unconstrained │ 1000000 │ ' 2821 ms' │ ' 62 ms' │ ' 45 ms' │ ' 1.38 x' │
│ Array_Object_Constrained │ 1000000 │ ' 2958 ms' │ ' 119 ms' │ ' 134 ms' │ ' 0.89 x' │
│ Array_Object_Recursive │ 1000000 │ ' 14695 ms' │ ' 1621 ms' │ ' 635 ms' │ ' 2.55 x' │
│ Array_Tuple_Primitive │ 1000000 │ ' 478 ms' │ ' 35 ms' │ ' 28 ms' │ ' 1.25 x' │
│ Array_Tuple_Object │ 1000000 │ ' 1623 ms' │ ' 63 ms' │ ' 48 ms' │ ' 1.31 x' │
│ Array_Composite_Intersect │ 1000000 │ ' 1582 ms' │ ' 43 ms' │ ' 30 ms' │ ' 1.43 x' │
│ Array_Composite_Union │ 1000000 │ ' 1331 ms' │ ' 76 ms' │ ' 40 ms' │ ' 1.90 x' │
│ Array_Math_Vector4 │ 1000000 │ ' 564 ms' │ ' 38 ms' │ ' 24 ms' │ ' 1.58 x' │
│ Array_Math_Matrix4 │ 1000000 │ ' 2382 ms' │ ' 111 ms' │ ' 83 ms' │ ' 1.34 x' │
└────────────────────────────┴────────────┴──────────────┴──────────────┴──────────────┴──────────────┘
Compression
The following table lists esbuild compiled and minified sizes for each TypeBox module.
┌──────────────────────┬────────────┬────────────┬─────────────┐
│ (index) │ Compiled │ Minified │ Compression │
├──────────────────────┼────────────┼────────────┼─────────────┤
│ typebox/compiler │ '122.4 kb' │ ' 53.4 kb' │ '2.29 x' │
│ typebox/errors │ ' 67.6 kb' │ ' 29.6 kb' │ '2.28 x' │
│ typebox/syntax │ '132.9 kb' │ ' 54.2 kb' │ '2.45 x' │
│ typebox/system │ ' 7.4 kb' │ ' 3.2 kb' │ '2.33 x' │
│ typebox/value │ '150.1 kb' │ ' 62.2 kb' │ '2.41 x' │
│ typebox │ '106.8 kb' │ ' 43.2 kb' │ '2.47 x' │
└──────────────────────┴────────────┴────────────┴─────────────┘
Contribute
TypeBox is open to community contribution. Please ensure you submit an open issue before submitting your pull request. The TypeBox project prefers open community discussion before accepting new features.
│
│ ]) │ │ } │
│ │ │ │
│ const T = Type │ │ │
│ .TemplateLiteral([ │ │ │
│ Type.Literal('on'), │ │ │
│ U │ │ │
│ ]) │ │ │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Record( │ type T = Record< │ const T = { │
│ Type.String(), │ string, │ type: 'object', │
│ Type.Number() │ number │ patternProperties: { │
│ ) │ > │ '^.*
JavaScript Types
TypeBox provides an extended type set that can be used to create schematics for common JavaScript constructs. These types can not be used with any standard Json Schema validator; but can be used to frame schematics for interfaces that may receive Json validated data. JavaScript types are prefixed with the __INLINE_CODE_0__ JSDoc comment for convenience. The following table lists the supported types.
__CODE_BLOCK_4__
Options
You can pass Json Schema options on the last argument of any given type. Option hints specific to each type are provided for convenience.
__CODE_BLOCK_5__
Properties
Object properties can be modified with Readonly and Optional. The following table shows how these modifiers map between TypeScript and Json Schema.
__CODE_BLOCK_6__
Generic Types
Generic types can be created with generic functions.
__CODE_BLOCK_7__
Recursive Types
Use the Recursive function to create recursive types.
__CODE_BLOCK_8__
Module Types
Module types are containers for a set of referential types. Modules act as namespaces, enabling types to reference one another via string identifiers. Modules support both singular and mutually recursive references, as well as deferred dereferencing for computed types such as Partial. Types imported from a module are expressed using the Json Schema __INLINE_CODE_1__ keyword.
__CODE_BLOCK_9__
Template Literal Types
TypeBox supports template literal types with the TemplateLiteral function. This type can be created using a syntax similar to the TypeScript template literal syntax or composed from exterior types. TypeBox encodes template literals as regular expressions which enables the template to be checked by Json Schema validators. This type also supports regular expression parsing that enables template patterns to be used for generative types. The following shows both TypeScript and TypeBox usage.
__CODE_BLOCK_10__
Indexed Access Types
TypeBox supports indexed access types with the Index function. This function enables uniform access to interior property and element types without having to extract them from the underlying schema representation. Index types are supported for Object, Array, Tuple, Union and Intersect types.
__CODE_BLOCK_11__
Mapped Types
TypeBox supports mapped types with the Mapped function. This function accepts two arguments, the first is a union type typically derived from KeyOf, the second is a mapping function that receives a mapping key __INLINE_CODE_2__ that can be used to index properties of a type. The following implements a mapped type that remaps each property to be __INLINE_CODE_3__.
__CODE_BLOCK_12__
Conditional Types
TypeBox supports runtime conditional types with the Extends function. This function performs a structural assignability check against the first (__INLINE_CODE_4__) and second (__INLINE_CODE_5__) arguments and will return either the third (__INLINE_CODE_6__) or fourth (__INLINE_CODE_7__) argument based on the result. The conditional types Exclude and Extract are also supported. The following shows both TypeScript and TypeBox examples of conditional types.
__CODE_BLOCK_13__
Transform Types
TypeBox supports value decoding and encoding with Transform types. These types work in tandem with the Encode and Decode functions available on the Value and TypeCompiler submodules. Transform types can be used to convert Json encoded values into constructs more natural to JavaScript. The following creates a Transform type to decode numbers into Dates using the Value submodule.
__CODE_BLOCK_14__
Use the StaticEncode or StaticDecode types to infer a Transform type.
__CODE_BLOCK_15__
Unsafe Types
TypeBox supports user defined types with Unsafe. This type allows you to specify both schema representation and inference type. The following creates an Unsafe type with a number schema that infers as string.
__CODE_BLOCK_16__
The Unsafe type is often used to create schematics for extended specifications like OpenAPI.
__CODE_BLOCK_17__
TypeGuard
TypeBox can check its own types with the TypeGuard module. This module is written for type introspection and provides structural tests for every built-in TypeBox type. Functions of this module return __INLINE_CODE_8__ guards which can be used with control flow assertions to obtain schema inference for unknown values. The following guards that the value __INLINE_CODE_9__ is TString.
__CODE_BLOCK_18__
Values
TypeBox provides an optional Value submodule that can be used to perform structural operations on JavaScript values. This submodule includes functionality to create, check and cast values from types as well as check equality, clone, diff and patch JavaScript values. This submodule is provided via optional import.
__CODE_BLOCK_19__
Assert
Use the Assert function to assert a value is valid.
__CODE_BLOCK_20__
Create
Use the Create function to create a value from a type. TypeBox will use default values if specified.
__CODE_BLOCK_21__
Clone
Use the Clone function to deeply clone a value.
__CODE_BLOCK_22__
Check
Use the Check function to type check a value.
__CODE_BLOCK_23__
Convert
Use the Convert function to convert a value into its target type if a reasonable conversion is possible. This function may return an invalid value and should be checked before use. Its return type is __INLINE_CODE_10__.
__CODE_BLOCK_24__
Clean
Use Clean to remove excess properties from a value. This function does not check the value and returns an unknown type. You should Check the result before use. Clean is a mutable operation. To avoid mutation, Clone the value first.
__CODE_BLOCK_25__
Default
Use Default to generate missing properties on a value using default schema annotations if available. This function does not check the value and returns an unknown type. You should Check the result before use. Default is a mutable operation. To avoid mutation, Clone the value first.
__CODE_BLOCK_26__
Cast
Use the Cast function to upcast a value into a target type. This function will retain as much information as possible from the original value. The Cast function is intended to be used in data migration scenarios where existing values need to be upgraded to match a modified type.
__CODE_BLOCK_27__
Decode
Use the Decode function to decode a value from a type or throw if the value is invalid. The return value will infer as the decoded type. This function will run Transform codecs if available.
__CODE_BLOCK_28__
Encode
Use the Encode function to encode a value to a type or throw if the value is invalid. The return value will infer as the encoded type. This function will run Transform codecs if available.
__CODE_BLOCK_29__
Parse
Use the Parse function to parse a value. This function calls the __INLINE_CODE_11__ __INLINE_CODE_12__, __INLINE_CODE_13__, __INLINE_CODE_14__, __INLINE_CODE_15__ and __INLINE_CODE_16__ Value functions in this exact order to process a value.
__CODE_BLOCK_30__
You can override the order in which functions are run, or omit functions entirely using the following.
__CODE_BLOCK_31__
Equal
Use the Equal function to deeply check for value equality.
__CODE_BLOCK_32__
Hash
Use the Hash function to create a FNV1A-64 non-cryptographic hash of a value.
__CODE_BLOCK_33__
Diff
Use the Diff function to generate a sequence of edits that will transform one value into another.
__CODE_BLOCK_34__
Patch
Use the Patch function to apply a sequence of edits.
__CODE_BLOCK_35__
Errors
Use the Errors function to enumerate validation errors.
__CODE_BLOCK_36__
Mutate
Use the Mutate function to perform a deep mutable value assignment while retaining internal references.
__CODE_BLOCK_37__
Pointer
Use ValuePointer to perform mutable updates on existing values using RFC6901 Json Pointers.
__CODE_BLOCK_38__
Syntax Types
TypeBox provides experimental support for parsing TypeScript annotation syntax into TypeBox types.
This feature is provided via optional import.
__CODE_BLOCK_39__
Create
Use the Syntax function to create TypeBox types from TypeScript syntax (Example)
__CODE_BLOCK_40__
Parameters
Syntax types can be parameterized to receive exterior types (Example)
__CODE_BLOCK_41__
Generics
Syntax types support generic parameters in the following way (Example)
__CODE_BLOCK_42__
Options
Options can be passed via the last parameter.
__CODE_BLOCK_43__
NoInfer
Syntax parsing is an expensive type level operation and can impact on language service performance. Use the NoInfer function parse syntax at runtime only.
__CODE_BLOCK_44__
TypeRegistry
The TypeBox type system can be extended with additional types and formats using the TypeRegistry and FormatRegistry modules. These modules integrate deeply with TypeBox's internal type checking infrastructure and can be used to create application specific types, or register schematics for alternative specifications.
TypeRegistry
Use the TypeRegistry to register a type. The Kind must match the registered type name.
__CODE_BLOCK_45__
FormatRegistry
Use the FormatRegistry to register a string format.
__CODE_BLOCK_46__
TypeCheck
TypeBox types target Json Schema Draft 7 and are compatible with any validator that supports this specification. TypeBox also provides a built-in type checking compiler designed specifically for TypeBox types that offers high performance compilation and value checking.
The following sections detail using Ajv and the TypeBox compiler infrastructure.
Ajv
The following shows the recommended setup for Ajv.
__CODE_BLOCK_47__
__CODE_BLOCK_48__
TypeCompiler
The TypeBox TypeCompiler is a high performance JIT validation compiler that transforms TypeBox types into optimized JavaScript validation routines. The compiler is tuned for fast compilation as well as fast value assertion. It is built to serve as a validation backend that can be integrated into larger applications. It can also be used for code generation.
The TypeCompiler is provided as an optional import.
__CODE_BLOCK_49__
Use the Compile function to JIT compile a type. Note that compilation is generally an expensive operation and should only be performed once per type during application start up. TypeBox does not cache previously compiled types, and applications are expected to hold references to each compiled type for the lifetime of the application.
__CODE_BLOCK_50__
Use the Errors function to generate diagnostic errors for a value. The Errors function will return an iterator that when enumerated; will perform an exhaustive check across the entire value yielding any error found. For performance, this function should only be called after a failed Check. Applications may also choose to yield only the first value to avoid exhaustive error generation.
__CODE_BLOCK_51__
Use the Code function to generate assertion functions as strings. This function can be used to generate code that can be written to disk as importable modules. This technique is sometimes referred to as Ahead of Time (AOT) compilation. The following generates code to check a string.
__CODE_BLOCK_52__
TypeMap
TypeBox offers an external package for bidirectional mapping between TypeBox, Valibot, and Zod type libraries. It also includes syntax parsing support for Valibot and Zod and supports the Standard Schema specification. For more details on TypeMap, refer to the project repository.
Usage
TypeMap needs to be installed separately
__CODE_BLOCK_53__
Once installed it offers advanced structural remapping between various runtime type libraries (Example)
__CODE_BLOCK_54__
TypeSystem
The TypeBox TypeSystem module provides configurations to use either Json Schema or TypeScript type checking semantics. Configurations made to the TypeSystem module are observed by the TypeCompiler, Value and Error modules.
Policies
TypeBox validates using standard Json Schema assertion policies by default. The TypeSystemPolicy module can override some of these to have TypeBox assert values inline with TypeScript static checks. It also provides overrides for certain checking rules related to non-serializable values (such as void) which can be helpful in Json based protocols such as Json Rpc 2.0.
The following overrides are available.
__CODE_BLOCK_55__
Error Function
Error messages in TypeBox can be customized by defining an ErrorFunction. This function allows for the localization of error messages as well as enabling custom error messages for custom types. By default, TypeBox will generate messages using the __INLINE_CODE_17__ locale. To support additional locales, you can replicate the function found in __INLINE_CODE_18__ and create a locale specific translation. The function can then be set via SetErrorFunction.
The following example shows an inline error function that intercepts errors for String, Number and Boolean only. The DefaultErrorFunction is used to return a default error message.
__CODE_BLOCK_56__
TypeBox Workbench
TypeBox offers a web based code generation tool that can convert TypeScript types into TypeBox types as well as several other ecosystem libraries.
TypeBox Codegen
TypeBox provides a code generation library that can be integrated into toolchains to automate type translation between TypeScript and TypeBox. This library also includes functionality to transform TypeScript types to other ecosystem libraries.
Ecosystem
The following is a list of community packages that offer general tooling, extended functionality and framework integration support for TypeBox.
Package
Description
drizzle-typebox
Generates TypeBox types from Drizzle ORM schemas
elysia
Fast and friendly Bun web framework
fastify-type-provider-typebox
Fastify TypeBox integration with the Fastify Type Provider
feathersjs
The API and real-time application framework
fetch-typebox
Drop-in replacement for fetch that brings easy integration with TypeBox
@lonli-lokli/fetcher-typebox
A strongly-typed fetch wrapper for TypeScript applications with optional runtime validation using TypeBox
h3-typebox
Schema validation utilities for h3 using TypeBox & Ajv
http-wizard
Type safe http client library for Fastify
json2typebox
Creating TypeBox code from Json Data
nominal-typebox
Allows devs to integrate nominal types into TypeBox schemas
openapi-box
Generate TypeBox types from OpenApi IDL + Http client library
prismabox
Converts a prisma.schema to TypeBox schema matching the database models
schema2typebox
Creating TypeBox code from Json Schemas
sveltekit-superforms
A comprehensive SvelteKit form library for server and client validation
ts2typebox
Creating TypeBox code from Typescript types
typebox-cli
Generate Schema with TypeBox from the CLI
typebox-form-parser
Parses form and query data based on TypeBox schemas
typebox-schema-faker
Generate fake data from TypeBox schemas for testing, prototyping and development
Benchmark
This project maintains a set of benchmarks that measure Ajv, Value and TypeCompiler compilation and validation performance. These benchmarks can be run locally by cloning this repository and running __INLINE_CODE_19__. The results below show for Ajv version 8.12.0 running on Node 20.10.0.
For additional comparative benchmarks, please refer to typescript-runtime-type-benchmarks.
Compile
This benchmark measures compilation performance for varying types.
__CODE_BLOCK_57__
Validate
This benchmark measures validation performance for varying types.
__CODE_BLOCK_58__
Compression
The following table lists esbuild compiled and minified sizes for each TypeBox module.
__CODE_BLOCK_59__
Contribute
TypeBox is open to community contribution. Please ensure you submit an open issue before submitting your pull request. The TypeBox project prefers open community discussion before accepting new features.
: { │
│ │ │ type: 'number' │
│ │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Partial( │ type T = Partial<{ │ const T = { │
│ Type.Object({ │ x: number, │ type: 'object', │
│ x: Type.Number(), │ y: number │ properties: { │
│ y: Type.Number() | }> │ x: { │
│ }) │ │ type: 'number' │
│ ) │ │ }, │
│ │ │ y: { │
│ │ │ type: 'number' │
│ │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Required( │ type T = Required<{ │ const T = { │
│ Type.Object({ │ x?: number, │ type: 'object', │
│ x: Type.Optional( │ y?: number │ required: ['x', 'y'], │
│ Type.Number() | }> │ properties: { │
│ ), │ │ x: { │
│ y: Type.Optional( │ │ type: 'number' │
│ Type.Number() │ │ }, │
│ ) │ │ y: { │
│ }) │ │ type: 'number' │
│ ) │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Pick( │ type T = Pick<{ │ const T = { │
│ Type.Object({ │ x: number, │ type: 'object', │
│ x: Type.Number(), │ y: number │ required: ['x'], │
│ y: Type.Number() │ }, 'x'> │ properties: { │
│ }), ['x'] | │ x: { │
│ ) │ │ type: 'number' │
│ │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Omit( │ type T = Omit<{ │ const T = { │
│ Type.Object({ │ x: number, │ type: 'object', │
│ x: Type.Number(), │ y: number │ required: ['y'], │
│ y: Type.Number() │ }, 'x'> │ properties: { │
│ }), ['x'] | │ y: { │
│ ) │ │ type: 'number' │
│ │ │ } │
│ │ │ } │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Index( │ type T = { │ const T = { │
│ Type.Object({ │ x: number, │ type: 'number' │
│ x: Type.Number(), │ y: string │ } │
│ y: Type.String() │ }['x'] │ │
│ }), ['x'] │ │ │
│ ) │ │ │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const A = Type.Tuple([ │ type A = [0, 1] │ const T = { │
│ Type.Literal(0), │ type B = [2, 3] │ type: 'array', │
│ Type.Literal(1) │ type T = [ │ items: [ │
│ ]) │ ...A, │ { const: 0 }, │
│ const B = Type.Tuple([ │ ...B │ { const: 1 }, │
| Type.Literal(2), │ ] │ { const: 2 }, │
| Type.Literal(3) │ │ { const: 3 } │
│ ]) │ │ ], │
│ const T = Type.Tuple([ │ │ additionalItems: false, │
| ...Type.Rest(A), │ │ minItems: 4, │
| ...Type.Rest(B) │ │ maxItems: 4 │
│ ]) │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Uncapitalize( │ type T = Uncapitalize< │ const T = { │
│ Type.Literal('Hello') │ 'Hello' │ type: 'string', │
│ ) │ > │ const: 'hello' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Capitalize( │ type T = Capitalize< │ const T = { │
│ Type.Literal('hello') │ 'hello' │ type: 'string', │
│ ) │ > │ const: 'Hello' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Uppercase( │ type T = Uppercase< │ const T = { │
│ Type.Literal('hello') │ 'hello' │ type: 'string', │
│ ) │ > │ const: 'HELLO' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const T = Type.Lowercase( │ type T = Lowercase< │ const T = { │
│ Type.Literal('HELLO') │ 'HELLO' │ type: 'string', │
│ ) │ > │ const: 'hello' │
│ │ │ } │
│ │ │ │
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
│ const R = Type.Ref('T') │ type R = unknown │ const R = { $ref: 'T' } │
│ │ │ │
└────────────────────────────────┴─────────────────────────────┴────────────────────────────────┘JavaScript Types
TypeBox provides an extended type set that can be used to create schematics for common JavaScript constructs. These types can not be used with any standard Json Schema validator; but can be used to frame schematics for interfaces that may receive Json validated data. JavaScript types are prefixed with the __INLINE_CODE_0__ JSDoc comment for convenience. The following table lists the supported types.
__CODE_BLOCK_4__Options
You can pass Json Schema options on the last argument of any given type. Option hints specific to each type are provided for convenience.
__CODE_BLOCK_5__Properties
Object properties can be modified with Readonly and Optional. The following table shows how these modifiers map between TypeScript and Json Schema.
__CODE_BLOCK_6__Generic Types
Generic types can be created with generic functions.
__CODE_BLOCK_7__Recursive Types
Use the Recursive function to create recursive types.
__CODE_BLOCK_8__Module Types
Module types are containers for a set of referential types. Modules act as namespaces, enabling types to reference one another via string identifiers. Modules support both singular and mutually recursive references, as well as deferred dereferencing for computed types such as Partial. Types imported from a module are expressed using the Json Schema __INLINE_CODE_1__ keyword.
__CODE_BLOCK_9__Template Literal Types
TypeBox supports template literal types with the TemplateLiteral function. This type can be created using a syntax similar to the TypeScript template literal syntax or composed from exterior types. TypeBox encodes template literals as regular expressions which enables the template to be checked by Json Schema validators. This type also supports regular expression parsing that enables template patterns to be used for generative types. The following shows both TypeScript and TypeBox usage.
__CODE_BLOCK_10__Indexed Access Types
TypeBox supports indexed access types with the Index function. This function enables uniform access to interior property and element types without having to extract them from the underlying schema representation. Index types are supported for Object, Array, Tuple, Union and Intersect types.
__CODE_BLOCK_11__Mapped Types
TypeBox supports mapped types with the Mapped function. This function accepts two arguments, the first is a union type typically derived from KeyOf, the second is a mapping function that receives a mapping key __INLINE_CODE_2__ that can be used to index properties of a type. The following implements a mapped type that remaps each property to be __INLINE_CODE_3__.
__CODE_BLOCK_12__Conditional Types
TypeBox supports runtime conditional types with the Extends function. This function performs a structural assignability check against the first (__INLINE_CODE_4__) and second (__INLINE_CODE_5__) arguments and will return either the third (__INLINE_CODE_6__) or fourth (__INLINE_CODE_7__) argument based on the result. The conditional types Exclude and Extract are also supported. The following shows both TypeScript and TypeBox examples of conditional types.
__CODE_BLOCK_13__Transform Types
TypeBox supports value decoding and encoding with Transform types. These types work in tandem with the Encode and Decode functions available on the Value and TypeCompiler submodules. Transform types can be used to convert Json encoded values into constructs more natural to JavaScript. The following creates a Transform type to decode numbers into Dates using the Value submodule.
__CODE_BLOCK_14__Use the StaticEncode or StaticDecode types to infer a Transform type.
__CODE_BLOCK_15__Unsafe Types
TypeBox supports user defined types with Unsafe. This type allows you to specify both schema representation and inference type. The following creates an Unsafe type with a number schema that infers as string.
__CODE_BLOCK_16__The Unsafe type is often used to create schematics for extended specifications like OpenAPI.
__CODE_BLOCK_17__TypeGuard
TypeBox can check its own types with the TypeGuard module. This module is written for type introspection and provides structural tests for every built-in TypeBox type. Functions of this module return __INLINE_CODE_8__ guards which can be used with control flow assertions to obtain schema inference for unknown values. The following guards that the value __INLINE_CODE_9__ is TString.
__CODE_BLOCK_18__Values
TypeBox provides an optional Value submodule that can be used to perform structural operations on JavaScript values. This submodule includes functionality to create, check and cast values from types as well as check equality, clone, diff and patch JavaScript values. This submodule is provided via optional import.
__CODE_BLOCK_19__Assert
Use the Assert function to assert a value is valid.
__CODE_BLOCK_20__Create
Use the Create function to create a value from a type. TypeBox will use default values if specified.
__CODE_BLOCK_21__Clone
Use the Clone function to deeply clone a value.
__CODE_BLOCK_22__Check
Use the Check function to type check a value.
__CODE_BLOCK_23__Convert
Use the Convert function to convert a value into its target type if a reasonable conversion is possible. This function may return an invalid value and should be checked before use. Its return type is __INLINE_CODE_10__.
__CODE_BLOCK_24__Clean
Use Clean to remove excess properties from a value. This function does not check the value and returns an unknown type. You should Check the result before use. Clean is a mutable operation. To avoid mutation, Clone the value first.
__CODE_BLOCK_25__Default
Use Default to generate missing properties on a value using default schema annotations if available. This function does not check the value and returns an unknown type. You should Check the result before use. Default is a mutable operation. To avoid mutation, Clone the value first.
__CODE_BLOCK_26__Cast
Use the Cast function to upcast a value into a target type. This function will retain as much information as possible from the original value. The Cast function is intended to be used in data migration scenarios where existing values need to be upgraded to match a modified type.
__CODE_BLOCK_27__Decode
Use the Decode function to decode a value from a type or throw if the value is invalid. The return value will infer as the decoded type. This function will run Transform codecs if available.
__CODE_BLOCK_28__Encode
Use the Encode function to encode a value to a type or throw if the value is invalid. The return value will infer as the encoded type. This function will run Transform codecs if available.
__CODE_BLOCK_29__Parse
Use the Parse function to parse a value. This function calls the __INLINE_CODE_11__ __INLINE_CODE_12__, __INLINE_CODE_13__, __INLINE_CODE_14__, __INLINE_CODE_15__ and __INLINE_CODE_16__ Value functions in this exact order to process a value.
__CODE_BLOCK_30__You can override the order in which functions are run, or omit functions entirely using the following.
__CODE_BLOCK_31__Equal
Use the Equal function to deeply check for value equality.
__CODE_BLOCK_32__Hash
Use the Hash function to create a FNV1A-64 non-cryptographic hash of a value.
__CODE_BLOCK_33__Diff
Use the Diff function to generate a sequence of edits that will transform one value into another.
__CODE_BLOCK_34__Patch
Use the Patch function to apply a sequence of edits.
__CODE_BLOCK_35__Errors
Use the Errors function to enumerate validation errors.
__CODE_BLOCK_36__Mutate
Use the Mutate function to perform a deep mutable value assignment while retaining internal references.
__CODE_BLOCK_37__Pointer
Use ValuePointer to perform mutable updates on existing values using RFC6901 Json Pointers.
__CODE_BLOCK_38__Syntax Types
TypeBox provides experimental support for parsing TypeScript annotation syntax into TypeBox types.
This feature is provided via optional import.
__CODE_BLOCK_39__Create
Use the Syntax function to create TypeBox types from TypeScript syntax (Example)
__CODE_BLOCK_40__Parameters
Syntax types can be parameterized to receive exterior types (Example)
__CODE_BLOCK_41__Generics
Syntax types support generic parameters in the following way (Example)
__CODE_BLOCK_42__Options
Options can be passed via the last parameter.
__CODE_BLOCK_43__NoInfer
Syntax parsing is an expensive type level operation and can impact on language service performance. Use the NoInfer function parse syntax at runtime only.
__CODE_BLOCK_44__TypeRegistry
The TypeBox type system can be extended with additional types and formats using the TypeRegistry and FormatRegistry modules. These modules integrate deeply with TypeBox's internal type checking infrastructure and can be used to create application specific types, or register schematics for alternative specifications.
TypeRegistry
Use the TypeRegistry to register a type. The Kind must match the registered type name.
__CODE_BLOCK_45__FormatRegistry
Use the FormatRegistry to register a string format.
__CODE_BLOCK_46__TypeCheck
TypeBox types target Json Schema Draft 7 and are compatible with any validator that supports this specification. TypeBox also provides a built-in type checking compiler designed specifically for TypeBox types that offers high performance compilation and value checking.
The following sections detail using Ajv and the TypeBox compiler infrastructure.
Ajv
The following shows the recommended setup for Ajv.
__CODE_BLOCK_47__ __CODE_BLOCK_48__TypeCompiler
The TypeBox TypeCompiler is a high performance JIT validation compiler that transforms TypeBox types into optimized JavaScript validation routines. The compiler is tuned for fast compilation as well as fast value assertion. It is built to serve as a validation backend that can be integrated into larger applications. It can also be used for code generation.
The TypeCompiler is provided as an optional import.
__CODE_BLOCK_49__Use the Compile function to JIT compile a type. Note that compilation is generally an expensive operation and should only be performed once per type during application start up. TypeBox does not cache previously compiled types, and applications are expected to hold references to each compiled type for the lifetime of the application.
__CODE_BLOCK_50__Use the Errors function to generate diagnostic errors for a value. The Errors function will return an iterator that when enumerated; will perform an exhaustive check across the entire value yielding any error found. For performance, this function should only be called after a failed Check. Applications may also choose to yield only the first value to avoid exhaustive error generation.
__CODE_BLOCK_51__Use the Code function to generate assertion functions as strings. This function can be used to generate code that can be written to disk as importable modules. This technique is sometimes referred to as Ahead of Time (AOT) compilation. The following generates code to check a string.
__CODE_BLOCK_52__TypeMap
TypeBox offers an external package for bidirectional mapping between TypeBox, Valibot, and Zod type libraries. It also includes syntax parsing support for Valibot and Zod and supports the Standard Schema specification. For more details on TypeMap, refer to the project repository.
Usage
TypeMap needs to be installed separately
__CODE_BLOCK_53__Once installed it offers advanced structural remapping between various runtime type libraries (Example)
__CODE_BLOCK_54__TypeSystem
The TypeBox TypeSystem module provides configurations to use either Json Schema or TypeScript type checking semantics. Configurations made to the TypeSystem module are observed by the TypeCompiler, Value and Error modules.
Policies
TypeBox validates using standard Json Schema assertion policies by default. The TypeSystemPolicy module can override some of these to have TypeBox assert values inline with TypeScript static checks. It also provides overrides for certain checking rules related to non-serializable values (such as void) which can be helpful in Json based protocols such as Json Rpc 2.0.
The following overrides are available.
__CODE_BLOCK_55__Error Function
Error messages in TypeBox can be customized by defining an ErrorFunction. This function allows for the localization of error messages as well as enabling custom error messages for custom types. By default, TypeBox will generate messages using the __INLINE_CODE_17__ locale. To support additional locales, you can replicate the function found in __INLINE_CODE_18__ and create a locale specific translation. The function can then be set via SetErrorFunction.
The following example shows an inline error function that intercepts errors for String, Number and Boolean only. The DefaultErrorFunction is used to return a default error message.
__CODE_BLOCK_56__TypeBox Workbench
TypeBox offers a web based code generation tool that can convert TypeScript types into TypeBox types as well as several other ecosystem libraries.
TypeBox Codegen
TypeBox provides a code generation library that can be integrated into toolchains to automate type translation between TypeScript and TypeBox. This library also includes functionality to transform TypeScript types to other ecosystem libraries.
Ecosystem
The following is a list of community packages that offer general tooling, extended functionality and framework integration support for TypeBox.
| Package | Description |
|---|---|
| drizzle-typebox | Generates TypeBox types from Drizzle ORM schemas |
| elysia | Fast and friendly Bun web framework |
| fastify-type-provider-typebox | Fastify TypeBox integration with the Fastify Type Provider |
| feathersjs | The API and real-time application framework |
| fetch-typebox | Drop-in replacement for fetch that brings easy integration with TypeBox |
| @lonli-lokli/fetcher-typebox | A strongly-typed fetch wrapper for TypeScript applications with optional runtime validation using TypeBox |
| h3-typebox | Schema validation utilities for h3 using TypeBox & Ajv |
| http-wizard | Type safe http client library for Fastify |
| json2typebox | Creating TypeBox code from Json Data |
| nominal-typebox | Allows devs to integrate nominal types into TypeBox schemas |
| openapi-box | Generate TypeBox types from OpenApi IDL + Http client library |
| prismabox | Converts a prisma.schema to TypeBox schema matching the database models |
| schema2typebox | Creating TypeBox code from Json Schemas |
| sveltekit-superforms | A comprehensive SvelteKit form library for server and client validation |
| ts2typebox | Creating TypeBox code from Typescript types |
| typebox-cli | Generate Schema with TypeBox from the CLI |
| typebox-form-parser | Parses form and query data based on TypeBox schemas |
| typebox-schema-faker | Generate fake data from TypeBox schemas for testing, prototyping and development |
Benchmark
This project maintains a set of benchmarks that measure Ajv, Value and TypeCompiler compilation and validation performance. These benchmarks can be run locally by cloning this repository and running __INLINE_CODE_19__. The results below show for Ajv version 8.12.0 running on Node 20.10.0.
For additional comparative benchmarks, please refer to typescript-runtime-type-benchmarks.
Compile
This benchmark measures compilation performance for varying types.
__CODE_BLOCK_57__Validate
This benchmark measures validation performance for varying types.
__CODE_BLOCK_58__Compression
The following table lists esbuild compiled and minified sizes for each TypeBox module.
__CODE_BLOCK_59__Contribute
TypeBox is open to community contribution. Please ensure you submit an open issue before submitting your pull request. The TypeBox project prefers open community discussion before accepting new features.