---
url: /plugins/plugin-faker/reference/options.md
description: Configuration options for @kubb/plugin-faker.
---

# Options

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

| Option | Type | Default | Description |
| ------ | ---- | ------- | ----------- |
| [`output`](#output) | `Output` | `{ path: 'mocks', barrel: { type: 'named' } }` | Where the generated files are written and exported |
| [`group`](#group) | `Group` | — | Split output into per-tag or per-path folders |
| [`dateParser`](#dateparser) | `'faker' \| 'dayjs' \| 'moment' \| string` | `'faker'` | Library that formats string date and time fields |
| [`regexGenerator`](#regexgenerator) | `'faker' \| 'randexp'` | `'faker'` | Library that turns a regex `pattern` into a string |
| [`locale`](#locale) | `string` | `'en'` | Faker locale code for the generated values |
| [`seed`](#seed) | `number \| number[]` | — | Value passed to `faker.seed(...)` for deterministic output |
| [`include`](#include) | `Array<Include>` | — | Keep only operations that match |
| [`exclude`](#exclude) | `Array<Exclude>` | `[]` | Skip operations that match |
| [`override`](#override) | `Array<Override>` | `[]` | Apply different options per pattern |
| [`resolver`](#resolver) | `ResolverPatch<ResolverFaker>` | — | Customize generated names and file paths |
| [`macros`](#macros) | `Array<Macro>` | — | Rewrite AST nodes before printing |
| [`printer`](#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'` 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`. Leave it unset and Kubb reads `output.path`: a name with an extension means one file, anything else a directory.

> \[!IMPORTANT]
> `group` works with the inferred directory mode, no `mode` needed. Set `mode: 'directory'` yourself only to override the inference, such as a directory name that carries a dot (`path: 'clients.v2'`). An explicit `mode: 'file'` still forbids `group` and stops the build with `KUBB_INVALID_PLUGIN_OPTIONS`, since a single file has nothing to group.

#### output.barrel

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

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. Kubb reads the plugin's own `output.barrel` first, falls back to `config.output.barrel` on `defineConfig`, and finally to `false`. Every generator plugin ships a default `output` that sets `barrel: { type: 'named' }`, but passing your own `output` replaces that object wholesale, so repeat `barrel` whenever you set `output` yourself.

#### 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.

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:

::: code-group

```typescript ['faker' (default)]
faker.date.anytime().toISOString().substring(0, 10)
```

```typescript ['dayjs']
dayjs(faker.date.anytime()).format('YYYY-MM-DD')
```

```typescript ['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](https://fakerjs.dev/api/localization.html) 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'`.

```typescript [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.

```typescript [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](/docs/5.x/guide/going-further/resolvers) 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.

```typescript [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](/docs/5.x/guide/going-further/macros) 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](/docs/5.x/guide/going-further/printers) covers how overrides compose with macros.

```typescript twoslash [Map integer schemas to a float]
import { pluginFaker } from '@kubb/plugin-faker'

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