---
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

```tstwoslash
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**:

<table>
<thead>
  <tr>
    <th>
      Property
    </th>
    
    <th>
      Type
    </th>
    
    <th>
      Default
    </th>
    
    <th>
      Description
    </th>
  </tr>
</thead>

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

### 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.

</note>

## `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

```tstwoslash
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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