Options

Configure @kubb/plugin-faker by passing these options to pluginFaker(), all of them optional.

Option	Type	Default	Description
output	Output	{ path: 'mocks' }	Where the generated files are written and exported
group	Group	—	Split output into per-tag or per-path folders
dateParser	'faker' | 'dayjs' | 'moment' | string	'faker'	Library that formats string date and time fields
regexGenerator	'faker' | 'randexp'	'faker'	Library that turns a regex pattern into a string
locale	string	'en'	Faker locale code for the generated values
seed	number | number[]	—	Value passed to faker.seed(...) for deterministic output
include	Array<Include>	—	Keep only operations that match
exclude	Array<Exclude>	—	Skip operations that match
override	Array<Override>	—	Apply different options per pattern
resolver	ResolverPatch<ResolverFaker>	—	Customize generated names and file paths
macros	Array<Macro>	—	Rewrite AST nodes before printing
printer	{ nodes?: PrinterFakerNodes }	—	Replace the handler for a schema type

output

Where the generated .ts files are written and how they are exported.

output.path

Folder where the plugin writes its files, resolved against the global output.path on defineConfig, and defaulting to 'mocks'. To write everything to one file, set output.mode: 'file' and give path a file name with its extension, such as 'mocks.ts'.

output.mode

How the plugin consolidates generated code. 'file' (the default) writes everything into a single file, where output.path must include the extension such as 'mocks.ts'. 'directory' writes one file per operation or schema under output.path.

IMPORTANT

group requires mode: 'directory'. Pairing group with mode: 'file' (or leaving mode unset) is invalid and fails with a KUBB_INVALID_PLUGIN_OPTIONS error.

output.barrel

Toggle the export style and depth to see the generated barrels.

• src/gen/
• models/
• Pet.ts
• User.ts
• clients/
• pet/
• getPetById.ts
• store/
• getInventory.ts

src/gen/index.ts

Controls how the generated index.ts (barrel) re-exports the output. Accepts { type: 'named' } or { type: 'all' }, optionally with nested: true (for example { type: 'named', nested: true }) to write an index.ts in every subdirectory, or false to skip the barrel entirely. Each generator plugin defaults output.barrel to { type: 'named' }; the root output.barrel on defineConfig defaults to false.

output.banner

Text added to the top of every generated file, such as a license header or @ts-nocheck directive. Pass a string, or a function (meta: BannerMeta) => string that receives the document info (title, description, version, baseURL) and per-file context (filePath, baseName, isBarrel, isAggregation), so a directive can skip barrel files.

output.footer

Text added to the bottom of every generated file (string or (meta: BannerMeta) => string), like banner but for closing comments. Pair banner: '/* eslint-disable */' with footer: '/* eslint-enable */' to scope a lint disable to the generated file.

group

Switch the mode to see where these operations land on disk.

clients/pet/

• getPetById
• addPet

clients/store/

• getInventory

clients/order/

• placeOrder
• getOrderById

clients/user/

• loginUser

group: { type: "tag" } splits the output by the operation tag, so placeOrder follows its order tag.

Splits generated files into subfolders by the operation's tag or URL path, each under {output.path}/{groupName}/. Without group, every file lands directly in output.path. It applies only to output.mode: 'directory'.

IMPORTANT

Combining group with output.mode: 'file' stops the build with a KUBB_INVALID_PLUGIN_OPTIONS error.

group.type

Property used to assign each operation to a group ('tag' | 'path'), required whenever group is set. An operation with no tag goes in the default group.

• 'tag' uses the operation's first tag.
• 'path' uses the first URL segment, such as pet for /pet/{petId}.

group.name

Function (context: { group: string }) => string that turns a group key into the subdirectory name and the suffix for aggregate files. It defaults to camelCase(group) for tag groups, and for type: 'path' groups uses the path segment as-is.

dateParser

Library used to format date and time fields represented as strings. Pick a value other than 'faker' when your project already uses a date library. Any library exporting a default function works, and Kubb adds the import for you.

A string date field renders differently per parser:

'faker' (default)

faker.date.anytime().toISOString().substring(0, 10)

'dayjs'

dayjs(faker.date.anytime()).format('YYYY-MM-DD')

'moment'

moment(faker.date.anytime()).format('YYYY-MM-DD')

regexGenerator

Library used to generate strings that satisfy a regex pattern keyword in the spec. The default 'faker' emits faker.helpers.fromRegExp(pattern) and needs no extra dependency. 'randexp' emits new RandExp(pattern).gen(), which supports a wider regex grammar but adds the randexp runtime dependency.

locale

Faker locale code. It switches the named import to fakerXX from @faker-js/faker, so generated values reflect the target region. The default 'en' imports fakerEN, 'de' imports fakerDE, and 'de_AT' imports fakerDE_AT. See Faker.js localization for all locale codes.

seed

Value passed to faker.seed(...) and emitted at the top of each generated factory, giving deterministic output across runs for snapshot tests and reproducible local data. Pass a single number or an array of numbers.

include

Generates only the operations and schemas that match at least one entry, and skips the rest. Each entry filters by tag, operationId, path, method, contentType, or schemaName, with a pattern that can be a string or a RegExp, both matched as a regular expression against the value. A string pattern is compiled with new RegExp(pattern), so it is not an exact match: pattern: 'pet' also matches 'petType' or 'superpet'.

Type definition

export type Include = {
  type: 'tag' | 'operationId' | 'path' | 'method' | 'contentType' | 'schemaName'
  pattern: string | RegExp
}

exclude

Skips any operation or schema that matches at least one entry, the opposite of include. Entries use the same type and pattern fields as include, and when both options match an item, exclude wins.

override

Applies different plugin options to operations that match a pattern. Each entry takes the same type and pattern as include, plus an options object that accepts any plugin option except override, so rules cannot nest. The first matching entry merges onto the plugin defaults, and later entries do not stack.

Type definition

export type Override = {
  type: 'tag' | 'operationId' | 'path' | 'method' | 'contentType' | 'schemaName'
  pattern: string | RegExp
  options: Omit<Partial<Options>, 'override'>
}

resolver

Changes how the plugin names generated files and symbols. Pass a partial patch: override only the members you want, and anything you omit keeps resolverFaker. See Override a resolver for the this context and how a patch layers over the default.

TIP

Inside a method this is the full resolver, so this.default.name(name) reuses the built-in casing.

Partial override

type ResolverFakerPatch = {
  name?(name: string): string
  file?: {
    baseName?(params: { name: string; extname: string }): string
    path?(params: { baseName: string; output: Output }): string
  }
  param?: {
    name?(node: OperationNode, param: ParameterNode): string    // → 'showPetByIdPathPetId'
    path?(node: OperationNode, param: ParameterNode): string     // → 'createShowPetByIdPath'
    query?(node: OperationNode, param: ParameterNode): string    // → 'createListPetsQuery'
    headers?(node: OperationNode, param: ParameterNode): string  // → 'createDeletePetHeaders'
  }
  response?: {
    status?(node: OperationNode, statusCode: StatusCode): string // → 'listPetsStatus200'
    body?(node: OperationNode): string                           // → 'createPetsBody'
    response?(node: OperationNode): string                       // → 'listPetsResponse'
    responses?(node: OperationNode): string                      // → 'listPetsResponses'
  }
}

macros

Rewrites AST nodes before they are printed, without forking the generator. Each macro callback (such as schema or operation) receives the node and a context object, and returns a replacement or undefined to leave it as is. Omitted callbacks keep their defaults, and macros run in order, so a later one sees the output of an earlier one.

printer

Replaces the Faker node handler for a specific schema type, such as 'integer', 'date', or 'string'. Each handler returns the Faker expression as a string. Use this.transform to recurse into nested nodes and this.options to read printer options. The printer guide covers how overrides compose with macros.

Map integer schemas to a float

import { pluginFaker } from '@kubb/plugin-faker'

pluginFaker({
  printer: {
    nodes: {
      integer() {
        return 'faker.number.float()'
      },
    },
  },
})