---
title: "Dependencies"
description: "Nuxt Kit provides utilities to check that optional dependencies are installed and to tell users how to install them."
canonical_url: "https://nuxt.com/docs/4.x/api/kit/dependencies"
---
# Dependencies

> Nuxt Kit provides utilities to check that optional dependencies are installed and to tell users how to install them.

Modules often depend on a package that only some projects need, or that the user is expected to install themselves. Rather than assuming the package is there, or printing an install command for a package manager the user does not use, Nuxt Kit can check whether a dependency is resolvable and offer to install it with the project's own package manager.

## `ensureDependencyInstalled`

Check that one or more dependencies are installed, prompting the user to install any that are missing.

### Usage

```ts twoslash
import { defineNuxtModule, ensureDependencyInstalled } from '@nuxt/kit'

export default defineNuxtModule({
  async setup () {
    if (!await ensureDependencyInstalled('sass')) {
      return
    }
  },
})
```

### Type

```ts
function ensureDependencyInstalled (names: string, options?: EnsureDependencyInstalledOptions): Promise<boolean>
function ensureDependencyInstalled (names: string[], options?: EnsureDependencyInstalledOptions): Promise<true | string[]>
```

### Parameters

**`names`**: One or more package names to check, and to install if they are missing.

**`options`**:

| Property      | Type       | Default                   | Description                                                                                                                                                                              |
| ------------- | ---------- | ------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `rootDir`     | `string`   | `nuxt.options.rootDir`    | Directory to resolve packages from and to install into.                                                                                                                                  |
| `searchPaths` | `string[]` | `nuxt.options.modulesDir` | Additional directories to resolve packages from.                                                                                                                                         |
| `from`        | `string`   | `undefined`               | An extra URL or path to resolve packages from, such as `import.meta.url`. Useful when your own package ships the dependency as a peer dependency.                                        |
| `prompt`      | `boolean`  | `undefined`               | Whether to prompt before installing. `true` always prompts, `false` never prompts (and installs automatically on StackBlitz), and leaving it unset prompts everywhere except StackBlitz. |

### Return Value

Passing a single package name returns `true` if it is available and `false` if it is not. Passing an array returns `true` if every package is available, or an array of the package names that are still missing (because the user declined, the install failed, or there was no interactive terminal).

::note
Nothing is installed in CI or when there is no interactive terminal. In that case the missing packages are reported as a diagnostic that includes the install command, and the function reports them as missing so your module can degrade gracefully.
::

## `getAddDependencyCommand`

Get the command a user should run to add dependencies to their project, using the package manager detected from `cwd` and falling back to `npm`. Use it whenever you print an install instruction, so the command matches the project's package manager.

### Usage

```ts twoslash
import { defineNuxtModule, getAddDependencyCommand, useLogger } from '@nuxt/kit'

export default defineNuxtModule({
  async setup (options, nuxt) {
    const logger = useLogger('my-module')
    const command = await getAddDependencyCommand('sass', nuxt.options.rootDir, { dev: true })

    logger.warn(`\`sass\` is required. Run \`${command}\` to install it.`)
  },
})
```

### Type

```ts
function getAddDependencyCommand (names: string | string[], cwd: string, options?: { dev?: boolean }): Promise<string>
```

### Parameters

**`names`**: One or more package names to install.

**`cwd`**: Directory to detect the package manager from.

**`options.dev`**: Whether the command should install the packages as dev dependencies.

---

- [Source](https://github.com/nuxt/nuxt/blob/main/packages/kit/src/dependency.ts)


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