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

# Options

Options for `@kubb/plugin-mcp`, which generates an MCP server where each OpenAPI operation becomes a typed tool handler.

| Option | Type | Default | Description |
| ------ | ---- | ------- | ----------- |
| [`output`](#output) | `Output` | `{ path: 'mcp', barrel: { type: 'named' } }` | Where the generated handlers are written and exported |
| [`group`](#group) | `Group` | — | Split output into per-tag or per-path folders |
| [`client`](#client) | `'fetch' \| 'axios'` | — | Which registered client plugin the handlers call |
| [`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<ResolverMcp>` | — | Customize generated names and file paths |
| [`macros`](#macros) | `Array<Macro>` | — | Rewrite AST nodes before printing |

### output

Where the generated MCP handler 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 `mcp`. To write everything into a single file, set `output.mode: 'file'` and give `path` a file name with its extension, such as `mcp.ts`.

#### output.mode

How the plugin consolidates its generated code. `'file'` writes everything into a single file whose `output.path` must include the extension, and `'directory'` writes one file per operation under `output.path`. Leave it unset and Kubb reads `output.path`: a name with an extension means one file, anything else a directory.

#### 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 that turns a group key into the subdirectory name under `output.path`. It defaults to the camelCased tag for `tag` groups and the first URL segment as-is for `path` groups. The `server.ts` and `.mcp.json` files keep their fixed names at the root of `output.path`.

### client

Selects which registered client plugin the handlers call, `'fetch'` for `@kubb/plugin-fetch` or `'axios'` for `@kubb/plugin-axios`. Each handler calls that client's generated `<op>` for the operation, passing one grouped `{ path, query, headers, body }` object. A lone registered client plugin is auto-detected, so set this only to disambiguate when both are registered, and transport options such as `baseURL` live on the client plugin itself.

> \[!NOTE]
> The handlers call a client plugin's functions, so register `@kubb/plugin-fetch` or `@kubb/plugin-axios` alongside this one.

### 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

A partial patch changes how the plugin names generated files and symbols. Override only the members you want, and anything you omit keeps `resolverMcp`. 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 ResolverMcpPatch = {
  name?(name: string): string
  file?: {
    baseName?(params: { name: string; extname: string }): string
    path?(params: { baseName: string; output: Output }): string
  }
  handler?: {
    name?(node: OperationNode): string     // → 'showPetByIdHandler'
  }
}
```

### 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.