# Your first nook

> Register a view, customize the chrome, drive the lifecycle.

You depend on OpenNook as a package and customize it through public API -
you do **not** fork the framework. Four steps take you from empty target to
running notch app.

## 1. Register a view

Hand `NookApp.main` your expanded home view; the top bar, Settings, hotkey,
and compact pill all come for free:

```swift
import NookApp
import SwiftUI

NookApp.main { MyHomeView() }
```

Run it and press **⌥⌘;** (or use the menu-bar item) to expand the nook.

## 2. Customize via `NookConfiguration`

Use this when you need more than a home view - the compact slots, the
chrome theme, the top bar's leading label/icon, the chrome flags, lifecycle
hooks, and file drops:

```swift
var configuration = NookConfiguration()
configuration.setHome { MyHomeView() }
configuration.setCompactTrailing { MyGlyph() }
configuration.theme = { appState in MyPalette.resolve(appState) }

// Top bar - leading cluster identity and chrome flags live on `topBar`.
configuration.topBar.leadingTitle = { _ in "Today" }  // default: "Home"
configuration.topBar.leadingIcon = "house"            // nil = brand mark; SF Symbol overrides
configuration.topBar.showsTopBar = true               // false strips top bar + gear + lock
configuration.topBar.showsSettings = true             // false drops the gear (top bar stays)

// Lifecycle hooks.
configuration.onExpand    = { print("nook expanded") }
configuration.onCompact   = { /* user dismissed / hover-exit collapsed the nook */ }
configuration.onHide      = { /* nook went hidden */ }
configuration.onFileDrop  = { urls in /* accept/reject dropped files */ true }
configuration.onReady     = { coordinator in /* post-launch handle for components */ }

NookApp.main(configuration)
```

Your views read the resolved palette from the `\.nookResolvedTheme`
environment value and shared services from `\.appServices`.

## 3. Add your state and services

`AppState` (`Sources/NookKit/App/AppState.swift`) holds chrome state - add
product state alongside it. `AppServices`
(`Sources/NookKit/App/AppServices.swift`) is the dependency container
threaded into views.

## 4. Drive the chrome

`AppCoordinator` exposes the lifecycle vocabulary: `showNook()`,
`hideNook()`, `toggleNook()`, `toggleKeepNookOpen()`. The global hotkey and
menu-bar fallback already call into them.

Rename the product (`Nook` -> your app) by editing `project.yml`,
`App/Info.plist`, and the `Package.swift` product name when you're ready
to ship. See [Shipping](/guides/shipping/) for the full checklist.