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TypeBox

JSON Schema Type Builder with Static Type Resolution for TypeScript



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Install

Node

$ npm install @sinclair/typebox --save

Deno and ESM

import { Static, Type } from 'https://esm.sh/@sinclair/typebox'

Example

import { Static, Type } from '@sinclair/typebox'

const T = Type.String()     // const T = { type: 'string' }

type T = Static<typeof T>   // type T = string

Overview

TypeBox is a type builder library that creates in-memory JSON Schema objects that can be statically inferred as TypeScript types. The schemas produced by this library are designed to match the static type checking rules of the TypeScript compiler. TypeBox enables one to create a unified type that can be statically checked by TypeScript and runtime asserted using standard JSON Schema validation.

TypeBox is designed to enable JSON schema to compose with the same flexibility as TypeScript's type system. It can be used either as a simple tool to build up complex schemas or integrated into REST and RPC services to help validate data received over the wire.

License MIT

Contents

Usage

The following demonstrates TypeBox's general usage.

import { Static, Type } 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
                                                     // }

//--------------------------------------------------------------------------------------------
//
// ... then use the type both as JSON schema and as a TypeScript type.
//
//--------------------------------------------------------------------------------------------

function receive(value: T) {                         // ... as a Type

  if(JSON.validate(T, value)) {                      // ... as a Schema
  
    // ok...
  }
}

Types

TypeBox provides a set of functions that allow you to compose JSON Schema similar to how you would compose static types with TypeScript. Each function creates a JSON schema fragment which can compose into more complex types. The schemas produced by TypeBox can be passed directly to any JSON Schema compliant validator, or used to reflect runtime metadata for a type.

Standard Types

The following table lists the Standard TypeBox types.

┌────────────────────────────────┬─────────────────────────────┬────────────────────────────────┐
 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.RegEx(/foo/)     type T = string              const T = {                    
                                                                 type: 'string',             
                                                                 pattern: 'foo'              
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 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                    properties: { })                              }                                 x: {                      
                                                                     type: 'number'          
                                                                   },                        
                                                                   y: {                      
                                                                     type: 'number'          
                                                                   }                         
                                                                },                           
                                                                required: ['x', 'y']         
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 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.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                    type: 'object',              
     x: Type.Number()            } & {                          properties: {   }),                             y: number                      x: {                       
   Type.Object({}                                  type: 'number'           
     y: Type.Number()                                             },                         
   })                                                             y: {                       
 ])                                                                 type: 'number'           
                                                                  }                          
                                                                },                           
                                                                required: ['x', 'y']         
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Never()          type T = never               const T = {                    
                                                                allOf: [{                    
                                                                  type: 'boolean',           
                                                                  const: false               
                                                                }, {                         
                                                                  type: 'boolean',           
                                                                  const: true                
                                                                }]                           
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Record(          type T = Record<             const T = {                    
   Type.String(),                  string,                      type: 'object',              
   Type.Number()                   number,                      patternProperties: {         
 )                               >                                '^.*$': {                  
                                                                    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                   properties: {                
       Type.Number()            | }>                               x: {                       
     ),                                                             type: 'number'           
     y: Type.Optional(                                            },                         
       Type.Number()                                              y: {                       
     )                                                              type: 'number'           
   })                                                             }                          
 )                                                              },                           
                                                                required: ['x', 'y']         
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Pick(            type T = Pick<{              const T = {                    
   Type.Object({                   x: number,                   type: 'object',              
     x: Type.Number(),             y: number                    properties: {                
     y: Type.Number()           | }, 'x'>                          x: {                       
   }), ['x']                                                        type: 'number'           
 )                                                                }                          
                                                                },                           
                                                                required: ['x']              
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Omit(            type T = Omit<{              const T = {                    
   Type.Object({                   x: number,                   type: 'object',              
     x: Type.Number(),             y: number                    properties: {                
     y: Type.Number()           | }, 'x'>                          y: {                       
   }), ['x']                                                        type: 'number'           
 )                                                                }                          
                                                                },                           
                                                                required: ['y']              
                                                              }                              
                                                                                             
└────────────────────────────────┴─────────────────────────────┴────────────────────────────────┘

Extended Types

TypeBox provides a set of extended types that can be used to express schematics for core JavaScript constructs and primitives. Extended types are not valid JSON Schema and will not validate using typical validation. These types however can be used to frame JSON schema and describe callable RPC interfaces that may receive JSON validated data.

┌────────────────────────────────┬─────────────────────────────┬────────────────────────────────┐
 TypeBox                         TypeScript                   Extended Schema                
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Constructor([    type T = new (               const T = {                    
   Type.String(),                 arg0: string,                 type: 'object',              
   Type.Number()                  arg1: number                  instanceOf: 'Constructor',   
 ], Type.Boolean())              ) => boolean                   parameters: [{               
                                                                  type: 'string'             
                                                                }, {                         
                                                                  type: 'number'             
                                                                }],                          
                                                                return: {                    
                                                                  type: 'boolean'            
                                                                }                            
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Function([       type T = (                   const T = {                    
|   Type.String(),                 arg0: string,                 type : 'object',             
   Type.Number()                  arg1: number                  instanceOf: 'Function',      
 ], Type.Boolean())              ) => boolean                   parameters: [{               
                                                                  type: 'string'             
                                                                }, {                         
                                                                  type: 'number'             
                                                                }],                          
                                                                return: {                    
                                                                  type: 'boolean'            
                                                                }                            
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Promise(         type T = Promise<string>     const T = {                    
   Type.String()                                                type: 'object',              
 )                                                              instanceOf: 'Promise',       
                                                                item: {                      
                                                                  type: 'string'             
                                                                }                            
                                                              }                              
                                                                                             
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Uint8Array()     type T = Uint8Array          const T = {                    
                                                                type: 'object',              
                                                                instanceOf: 'Uint8Array'     
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Date()           type T = Date                const T = {                    
                                                                type: 'object',              
                                                                instanceOf: 'Date'           
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Undefined()      type T = undefined           const T = {                    
                                                                type: 'null',                
                                                                typeOf: 'Undefined'          
                                                              }                              
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Void()           type T = void                const T = {                    
                                                                type: 'null'                 
                                                                typeOf: 'Void'               
                                                              }                              
                                                                                             
└────────────────────────────────┴─────────────────────────────┴────────────────────────────────┘

Modifiers

TypeBox provides modifiers that can be applied to an objects properties. This allows for optional and readonly to be applied to that property. The following table illustates how they map between TypeScript and JSON Schema.

┌────────────────────────────────┬─────────────────────────────┬────────────────────────────────┐
 TypeBox                         TypeScript                   JSON Schema                    
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Type.Object({         type T = {                   const T = {                    
   name: Type.Optional(            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.ReadonlyOptional(    readonly name?: string       type: 'object',              
     Type.String()               }                              properties: {                
   )                                                              name: {                    
 })  	                                                             type: 'string'           
                                                                  }                          
                                                                }                            
                                                              }                              
                                                                                             
└────────────────────────────────┴─────────────────────────────┴────────────────────────────────┘

Options

You can pass additional JSON schema options on the last argument of any given type. The following are some examples.

// string must be an email
const T = Type.String({ format: 'email' })

// number must be a multiple of 2
const T = Type.Number({ multipleOf: 2 })

// array must have at least 5 integer values
const T = Type.Array(Type.Integer(), { minItems: 5 })

Reference

Use Type.Ref(...) to create referenced types. The target type must specify an $id.

const T = Type.String({ $id: 'T' })                  // const T = {
                                                     //    $id: 'T',
                                                     //    type: 'string'
                                                     // }
                                             
const R = Type.Ref(T)                                // const R = {
                                                     //    $ref: 'T'
                                                     // }

Recursive

Use Type.Recursive(...) to create recursive types.

const Node = Type.Recursive(Node => Type.Object({    // const Node = {
  id: Type.String(),                                 //   $id: 'Node',
  nodes: Type.Array(Node)                            //   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 is string
                 .nodes[0].nodes[0]
                 .id
}

Generic

Use functions to create generic types. The following creates a generic Nullable<T> type.

import { Type, Static, TSchema } from '@sinclair/typebox'

const Nullable = <T extends TSchema>(type: T) => Type.Union([type, Type.Null()])

const T = Nullable(Type.String())                    // const T = {
                                                     //   anyOf: [{
                                                     //     type: 'string'
                                                     //   }, {
                                                     //     type: 'null'
                                                     //   }]
                                                     // }

type T = Static<typeof T>                            // type T = string | null

const U = Nullable(Type.Number())                    // const U = {
                                                     //   anyOf: [{
                                                     //     type: 'number'
                                                     //   }, {
                                                     //     type: 'null'
                                                     //   }]
                                                     // }

type U = Static<typeof U>                            // type U = number | null

Conditional

Use the conditional module to create Conditional Types. This module implements TypeScript's structural equivalence checks to enable TypeBox types to be conditionally inferred at runtime. This module also provides the Extract and Exclude utility types which are expressed as conditional types in TypeScript.

The conditional module is provided as an optional import.

import { Conditional } from '@sinclair/typebox/conditional'

The following table shows the TypeBox mappings between TypeScript and JSON schema.

┌────────────────────────────────┬─────────────────────────────┬────────────────────────────────┐
 TypeBox                         TypeScript                   JSON Schema                    
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Conditional.Extends(  type T =                     const T = {                    
   Type.String(),                 string extends number         const: false,                
   Type.Number(),                 true : false                  type: 'boolean'              
   Type.Literal(true),                                        }                              
   Type.Literal(false)                                                                       
 )                                                                                           
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Conditional.Extract(  type T = Extract<            const T = {                    
   Type.Union([                    'a' | 'b' | 'c',             anyOf: [{                    
     Type.Literal('a'),            'a' | 'f'                      const: 'a'                 
     Type.Literal('b'),          >                                type: 'string'             
     Type.Literal('c')                                          }]                           
   ]),                                                        }                              
   Type.Union([                                                                              
     Type.Literal('a'),                                                                      
     Type.Literal('f')                                                                       
   ])                                                                                        
 )                                                                                           
                                                                                             
├────────────────────────────────┼─────────────────────────────┼────────────────────────────────┤
 const T = Conditional.Exclude(  type T = Exclude<            const T = {                    
   Type.Union([                    'a' | 'b' | 'c',             anyOf: [{                    
     Type.Literal('a'),            'a'                            const: 'b',                
     Type.Literal('b'),          >                                type: 'string'             
     Type.Literal('c')                                          }, {                         
   ]),                                                            const: 'c',                
   Type.Union([                                                   type: 'string'             
     Type.Literal('a')                                          }]                           
   ])                                                         }                              
 )                                                                                           
                                                                                             
└────────────────────────────────┴─────────────────────────────┴────────────────────────────────┘

Unsafe

Use Type.Unsafe(...) to create custom schemas with user defined inference rules.

const T = Type.Unsafe<string>({ type: 'number' })    // const T = {
                                                     //   type: 'number'
                                                     // }

type T = Static<typeof T>                            // type T = string

This function can be used to create custom schemas for validators that require specific schema representations. An example of this might be OpenAPI's nullable and enum schemas which are not provided by TypeBox. The following demonstrates using Type.Unsafe(...) to create these types.

import { Type, Static, TSchema } from '@sinclair/typebox'

//--------------------------------------------------------------------------------------------
//
// Nullable<T>
//
//--------------------------------------------------------------------------------------------

function Nullable<T extends TSchema>(schema: T) {
  return 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


//--------------------------------------------------------------------------------------------
//
// StringEnum<string[]>
//
//--------------------------------------------------------------------------------------------

function StringEnum<T extends string[]>(values: [...T]) {
  return Type.Unsafe<T[number]>({ type: 'string', enum: values })
}

const T = StringEnum(['A', 'B', 'C'])                // const T = {
                                                     //   enum: ['A', 'B', 'C']
                                                     // }

type T = Static<typeof T>                            // type T = 'A' | 'B' | 'C'

Guards

Use the guard module to test if values are TypeBox types.

import { TypeGuard } from '@sinclair/typebox/guard'

const T = Type.String()

if(TypeGuard.TString(T)) {
    
  // T is TString
}

Strict

TypeBox schemas contain the Kind and Modifier symbol properties. These properties are provided to enable runtime type reflection on schemas, as well as helping TypeBox internally compose types. These properties are not strictly valid JSON schema; so in some cases it may be desirable to omit them. TypeBox provides a Type.Strict() function that will omit these properties if necessary.

const T = Type.Object({                              // const T = {
  name: Type.Optional(Type.String())                 //   [Kind]: 'Object',
})                                                   //   type: 'object',
                                                     //   properties: {
                                                     //     name: {
                                                     //       [Kind]: 'String',
                                                     //       type: 'string',
                                                     //       [Modifier]: 'Optional'
                                                     //     }
                                                     //   }
                                                     // }

const U = Type.Strict(T)                             // const U = {
                                                     //   type: 'object', 
                                                     //   properties: { 
                                                     //     name: { 
                                                     //       type: 'string' 
                                                     //     } 
                                                     //   } 
                                                     // }

Values

TypeBox includes an optional values module that can be used to perform common operations on JavaScript values. This module enables one to create, check and cast values from types. It also provides functionality to check equality, clone and diff and patch JavaScript values. The value module is provided as an optional import.

import { Value } from '@sinclair/typebox/value'

Create

Use the Create function to create a value from a TypeBox 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

Cast

Use the Cast function to cast a value into a type. The cast function will retain as much information as possible from the original value.

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 }

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 }
)

Diff

Use the Diff function to produce a sequence of edits to 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 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 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'
                                                     // }]

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)                         // const A = { x: 1, y: 0, z: 0 }
ValuePointer.Set(A, '/y', 1)                         // const A = { x: 1, y: 1, z: 0 }
ValuePointer.Set(A, '/z', 1)                         // const A = { x: 1, y: 1, z: 1 }

TypeCheck

TypeBox targets JSON Schema Draft 6 and is built and tested against the Ajv JSON Schema validator for standards compliance. TypeBox also includes an optional built-in TypeCompiler that can provide improved compilation and validation performance specifically for TypeBox types only.

The following sections detail using these validators.

Ajv

The following are the recommended configurations to support both the Standard and Extended type sets provided by TypeBox. For schema portability and publishing to remote systems, it is recommended to use the Standard type set only.

$ npm install ajv ajv-formats --save
Standard Ajv Configuration

Expand for Standard Type Set Configuration

import { Type }   from '@sinclair/typebox'
import addFormats from 'ajv-formats'
import Ajv        from 'ajv'

export function createAjv() {
  return addFormats(new Ajv({}), [
    'date-time', 
    'time', 
    'date', 
    'email',  
    'hostname', 
    'ipv4', 
    'ipv6', 
    'uri', 
    'uri-reference', 
    'uuid',
    'uri-template', 
    'json-pointer', 
    'relative-json-pointer', 
    'regex'
  ])
}

const ajv = createAjv()

const R = ajv.validate(Type.Object({                 // const R = true
  x: Type.Number(),
  y: Type.Number(),
  z: Type.Number()
}), { x: 1, y: 2, z: 3 })     
Extended Ajv Configuration

Expand for Extended Type Set Configuration

import { TypeGuard } from '@sinclair/typebox/guard'
import { Value }     from '@sinclair/typebox/value'
import { Type }      from '@sinclair/typebox'
import addFormats    from 'ajv-formats'
import Ajv           from 'ajv'

function schemaOf(schemaOf: string, value: unknown, schema: unknown) {
  switch (schemaOf) {
    case 'Constructor':
      return TypeGuard.TConstructor(schema) && Value.Check(schema, value) // not supported
    case 'Function':
      return TypeGuard.TFunction(schema) && Value.Check(schema, value) // not supported
    case 'Date':
      return TypeGuard.TDate(schema) && Value.Check(schema, value)
    case 'Promise':
      return TypeGuard.TPromise(schema) && Value.Check(schema, value) // not supported
    case 'Uint8Array':
      return TypeGuard.TUint8Array(schema) && Value.Check(schema, value)
    case 'Undefined':
      return TypeGuard.TUndefined(schema) && Value.Check(schema, value) // not supported
    case 'Void':
      return TypeGuard.TVoid(schema) && Value.Check(schema, value)
    default:
      return false
  }
}

export function createAjv() {
  return addFormats(new Ajv({}), [
    'date-time', 
    'time', 
    'date', 
    'email',  
    'hostname', 
    'ipv4', 
    'ipv6', 
    'uri', 
    'uri-reference', 
    'uuid',
    'uri-template', 
    'json-pointer', 
    'relative-json-pointer', 
    'regex'
  ])
  .addKeyword({ type: 'object', keyword: 'instanceOf', validate: schemaOf })
  .addKeyword({ type: 'null', keyword: 'typeOf', validate: schemaOf })
  .addKeyword('exclusiveMinimumTimestamp')
  .addKeyword('exclusiveMaximumTimestamp')
  .addKeyword('minimumTimestamp')
  .addKeyword('maximumTimestamp')
  .addKeyword('minByteLength')
  .addKeyword('maxByteLength')
}

const ajv = createAjv()

const R = ajv.validate(Type.Object({                 // const R = true
  buffer: Type.Uint8Array(),
  date: Type.Date(),
  void: Type.Void()
}), {
  buffer: new Uint8Array(),
  date: new Date(),
  void: null
})

TypeCompiler

TypeBox provides an optional high performance just-in-time (JIT) compiler and type checker that can be used in applications that require extremely fast validation. Note that this compiler is optimized for TypeBox types only where the schematics are known in advance. If defining custom types with Type.Unsafe<T> please consider Ajv.

The compiler module is provided as an optional import.

import { TypeCompiler } from '@sinclair/typebox/compiler'

Use the Compile(...) function to compile a type.

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

Validation errors can be read with the Errors(...) function.

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 errors = [...C.Errors(value)]                  // const errors = [{
                                                     //   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'
                                                     // }]

Compiled routines can be inspected with the .Code() function.

const C = TypeCompiler.Compile(Type.String())        // const C: TypeCheck<TString>

console.log(C.Code())                                // return function check(value) {
                                                     //   return (
                                                     //     (typeof value === 'string')
                                                     //   )
                                                     // }

Formats

Use the format module to create user defined string formats. The format module is used by the Value and TypeCompiler modules only. If using Ajv, please refer to the official Ajv format documentation located here.

The format module is an optional import.

import { Format } from '@sinclair/typebox/format'

The following creates a palindrome string format.

Format.Set('palindrome', value => value === value.split('').reverse().join(''))

Once set, this format can then be used by the TypeCompiler and Value modules.

const T = Type.String({ format: 'palindrome' })

const A = TypeCompiler.Compile(T).Check('engine')    // const A = false

const B = Value.Check(T, 'kayak')                    // const B = true

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 8.11.0.

For additional comparative benchmarks, please refer to typescript-runtime-type-benchmarks.

Compile

This benchmark measures compilation performance for varying types. You can review this benchmark here.

┌──────────────────┬────────────┬──────────────┬──────────────┬──────────────┐
     (index)       Iterations      Ajv       TypeCompiler  Performance  
├──────────────────┼────────────┼──────────────┼──────────────┼──────────────┤
           Number     2000     '    421 ms'  '     11 ms'  '   38.27 x' 
           String     2000     '    332 ms'  '     11 ms'  '   30.18 x' 
          Boolean     2000     '    291 ms'  '     12 ms'  '   24.25 x' 
             Null     2000     '    266 ms'  '      9 ms'  '   29.56 x' 
            RegEx     2000     '    486 ms'  '     17 ms'  '   28.59 x' 
          ObjectA     2000     '   2791 ms'  '     50 ms'  '   55.82 x' 
          ObjectB     2000     '   2896 ms'  '     37 ms'  '   78.27 x' 
            Tuple     2000     '   1244 ms'  '     21 ms'  '   59.24 x' 
            Union     2000     '   1258 ms'  '     25 ms'  '   50.32 x' 
          Vector4     2000     '   1513 ms'  '     21 ms'  '   72.05 x' 
          Matrix4     2000     '    850 ms'  '     11 ms'  '   77.27 x' 
   Literal_String     2000     '    335 ms'  '      7 ms'  '   47.86 x' 
   Literal_Number     2000     '    358 ms'  '      7 ms'  '   51.14 x' 
  Literal_Boolean     2000     '    356 ms'  '      7 ms'  '   50.86 x' 
     Array_Number     2000     '    689 ms'  '      9 ms'  '   76.56 x' 
     Array_String     2000     '    728 ms'  '     12 ms'  '   60.67 x' 
    Array_Boolean     2000     '    726 ms'  '      7 ms'  '  103.71 x' 
    Array_ObjectA     2000     '   3631 ms'  '     35 ms'  '  103.74 x' 
    Array_ObjectB     2000     '   3636 ms'  '     40 ms'  '   90.90 x' 
      Array_Tuple     2000     '   2119 ms'  '     31 ms'  '   68.35 x' 
      Array_Union     2000     '   1550 ms'  '     23 ms'  '   67.39 x' 
    Array_Vector4     2000     '   2200 ms'  '     18 ms'  '  122.22 x' 
    Array_Matrix4     2000     '   1494 ms'  '     14 ms'  '  106.71 x' 
└──────────────────┴────────────┴──────────────┴──────────────┴──────────────┘

Validate

This benchmark measures validation performance for varying types. You can review this benchmark here.

┌──────────────────┬────────────┬──────────────┬──────────────┬──────────────┬──────────────┐
     (index)       Iterations   ValueCheck       Ajv       TypeCompiler  Performance  
├──────────────────┼────────────┼──────────────┼──────────────┼──────────────┼──────────────┤
           Number   1000000    '     28 ms'  '      6 ms'  '      6 ms'  '    1.00 x' 
           String   1000000    '     25 ms'  '     20 ms'  '     11 ms'  '    1.82 x' 
          Boolean   1000000    '     34 ms'  '     22 ms'  '     13 ms'  '    1.69 x' 
             Null   1000000    '     37 ms'  '     28 ms'  '     10 ms'  '    2.80 x' 
            RegEx   1000000    '    162 ms'  '     50 ms'  '     37 ms'  '    1.35 x' 
          ObjectA   1000000    '    550 ms'  '     38 ms'  '     22 ms'  '    1.73 x' 
          ObjectB   1000000    '   1033 ms'  '     58 ms'  '     38 ms'  '    1.53 x' 
            Tuple   1000000    '    126 ms'  '     24 ms'  '     14 ms'  '    1.71 x' 
            Union   1000000    '    326 ms'  '     25 ms'  '     16 ms'  '    1.56 x' 
        Recursive   1000000    '   3089 ms'  '    436 ms'  '    101 ms'  '    4.32 x' 
          Vector4   1000000    '    155 ms'  '     24 ms'  '     12 ms'  '    2.00 x' 
          Matrix4   1000000    '    579 ms'  '     41 ms'  '     28 ms'  '    1.46 x' 
   Literal_String   1000000    '     50 ms'  '     21 ms'  '     13 ms'  '    1.62 x' 
   Literal_Number   1000000    '     46 ms'  '     22 ms'  '     11 ms'  '    2.00 x' 
  Literal_Boolean   1000000    '     48 ms'  '     20 ms'  '     10 ms'  '    2.00 x' 
     Array_Number   1000000    '    424 ms'  '     32 ms'  '     19 ms'  '    1.68 x' 
     Array_String   1000000    '    483 ms'  '     34 ms'  '     28 ms'  '    1.21 x' 
    Array_Boolean   1000000    '    432 ms'  '     35 ms'  '     26 ms'  '    1.35 x' 
    Array_ObjectA   1000000    '  13895 ms'  '   2440 ms'  '   1495 ms'  '    1.63 x' 
    Array_ObjectB   1000000    '  16261 ms'  '   2633 ms'  '   2011 ms'  '    1.31 x' 
      Array_Tuple   1000000    '   1741 ms'  '     98 ms'  '     66 ms'  '    1.48 x' 
      Array_Union   1000000    '   4825 ms'  '    232 ms'  '     87 ms'  '    2.67 x' 
  Array_Recursive   1000000    '  54158 ms'  '   6966 ms'  '   1173 ms'  '    5.94 x' 
    Array_Vector4   1000000    '   2577 ms'  '     99 ms'  '     48 ms'  '    2.06 x' 
    Array_Matrix4   1000000    '  12648 ms'  '    397 ms'  '    249 ms'  '    1.59 x' 
└──────────────────┴────────────┴──────────────┴──────────────┴──────────────┴──────────────┘

Compression

The following table lists esbuild compiled and minified sizes for each TypeBox module.

┌──────────────────────┬────────────┬────────────┬─────────────┐
       (index)          Compiled    Minified   Compression 
├──────────────────────┼────────────┼────────────┼─────────────┤
 typebox/compiler      '   54 kb'  '   27 kb'   '1.97 x'   
 typebox/conditional   '   44 kb'  '   17 kb'   '2.45 x'   
 typebox/format        '    0 kb'  '    0 kb'   '2.66 x'   
 typebox/guard         '   22 kb'  '   11 kb'   '2.05 x'   
 typebox/value         '   78 kb'  '   36 kb'   '2.13 x'   
 typebox               '   12 kb'  '    6 kb'   '1.89 x'   
└──────────────────────┴────────────┴────────────┴─────────────┘

Contribute

TypeBox is open to community contribution. Please ensure you submit an open issue before submitting your pull request. The TypeBox project preferences open community discussion prior to accepting new features.