# Using external modules and plugings with Nuxt.js
## Configuration: `vendor`
> Nuxt.js allows you to add modules inside the `vendor.bundle.js` file generated to reduce the size of the app bundle. It's really useful when using external modules (like `axios` for example)
To add a module/file inside the vendor bundle, add the `vendor` key inside `nuxt.config.js`:
I want to use [vue-notifications](https://github.com/se-panfilov/vue-notifications) to validate the data in my inputs, I need to setup the plugin before launching the app.
I added `vue-notifications` in the `vendor` key to make sure that it won't be included in any other build if I call `require('vue-notifications')` in a component.
Some plugins might work only in the browser, for this, you can use the `process.BROWSER` variable to check if the plugin will run from the server or from the client.