> ## Documentation Index
> Fetch the complete documentation index at: https://bun.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Add an optional dependency

To add an npm package as an optional dependency, use the `--optional` flag.

```sh terminal icon="terminal" theme={"theme":{"light":"github-light","dark":"dracula"}}
bun add zod --optional
```

***

This will add the package to `optionalDependencies` in `package.json`.

```json package.json icon="file-json" theme={"theme":{"light":"github-light","dark":"dracula"}}
{
  "optionalDependencies": {
    "zod": "^3.0.0" // [!code ++]
  }
}
```

***

See [Docs > Package manager](/pm/cli/install) for complete documentation of Bun's package manager.