---
title: Configuration
description: Configure `build/flecks.yml` and your application.
---

import InstallPackage from '@site/helpers/install-package';

# Configuration

You have a flecks application! ...but it doesn't do much. This is because a flecks application is
composed of individual flecks and by default, your application will have only two flecks:
`@flecks/core` and `@flecks/server`. Your `build/flecks.yml` file will look like this:

```yml
'@flecks/core': {}
'@flecks/server': {}
```

Each fleck may have configuration that can be set through `build/flecks.yml`.
For a deep dive of configurable core flecks, see
[the generated configuration page](/docs/flecks/@flecks/dox/config).

## `build/flecks.yml`

A good first configuration step is to set the ID of your application.

Your `build/flecks.yml` will look like this after you generate your application:

```yml
'@flecks/core': {}
'@flecks/server': {}
```

Your application's ID is configured at the `id` key of `@flecks/core`'s configuration. To set your
application's ID to `hello_world`, update your `build/flecks.yml` to look like this:

```yml
// highlight-start
'@flecks/core':
  id: 'hello_world'
// highlight-end
'@flecks/server': {}
```

## Adding more

If you were studious enough to take a peek at [the generated configuration page](/docs/flecks/@flecks/dox/config)
above, you may have noticed that there were a lot more flecks there than just the two in our
application.

For instance, there is a `@flecks/web` fleck that turns your little old server application into one
that can build and serve a webpage. You can add it to your application in two steps.

1. Add the package to your project using your favorite package manager:

<InstallPackage pkg="@flecks/web" />

2. Add the fleck to your `build/flecks.yml`:

```yml
'@flecks/core':
  id: 'hello_world'
'@flecks/server': {}
// highlight-next-line
'@flecks/web': {}
```

Now, if you run `npm start`, you'll see a line in the output:

```
  @flecks/web/server/http HTTP server up @ 0.0.0.0:32340!
```

## Finally... a white page?

If you visit `localhost:32340` in your browser, you should now see... a blank white page! Don't fret
though; if you open the devtools in your browser, you will see a little messaging from your
application that will look something like:

```
[webpack-dev-server] Server started: Hot Module Replacement enabled, Live Reloading enabled, Progress disabled, Overlay enabled.
[HMR] Waiting for update signal from WDS...
flecks client v2.0.3 loading runtime...
```

This is a good sign! This means we successfully added a web server with HMR enabled by default.
Oh, the possibilities...

## Proceed with the hooking

How does flecks know to start the web server when the application starts? Great question! This is
accomplished through the use of [hooks](#todo).

Next, we'll learn how to create our own fleck and do a little hooking of our own. Take that, dad!