---
id: appregistry
title: AppRegistry
layout: docs
category: APIs
permalink: docs/appregistry.html
next: appstate
previous: animated
---

<div class="banner-crna-ejected">
  <h3>Project with Native Code Required</h3>
  <p>
    This API only works in projects made with <code>react-native init</code> or in those made with Create React Native App which have since ejected. For more information about ejecting, please see the <a href="https://github.com/react-community/create-react-native-app/blob/master/EJECTING.md" target="_blank">guide</a> on the Create React Native App repository.
  </p>
</div>

`AppRegistry` is the JavaScript entry point to running all React Native apps. App root components should register themselves with `AppRegistry.registerComponent()`, then the native system can load the bundle for the app and then actually run the app when it's ready by invoking `AppRegistry.runApplication()`.

To "stop" an application when a view should be destroyed, call `AppRegistry.unmountApplicationComponentAtRootTag()` with the tag that was passed into `runApplication()`. These should always be used as a pair.
 
`AppRegistry` should be `require`d early in the `require` sequence to make sure the JavaScript execution environment is set up before other modules are `require`d.

### Methods

- [`registerComponent`](docs/appregistry.html#registercomponent)
- [`runApplication`](docs/appregistry.html#runapplication)
- [`unmountApplicationComponentAtRootTag`](docs/appregistry.html#unmountapplicationcomponentatroottag)
- [`registerHeadlessTask`](docs/appregistry.html#registerheadlesstask)
- [`startHeadlessTask`](docs/appregistry.html#startheadlesstask)
- [`setWrapperComponentProvider`](docs/appregistry.html#setwrappercomponentprovider)
- [`registerConfig`](docs/appregistry.html#registerconfig)
- [`registerRunnable`](docs/appregistry.html#registerrunnable)
- [`registerSection`](docs/appregistry.html#registersection)
- [`getAppKeys`](docs/appregistry.html#getappkeys)
- [`getSectionKeys`](docs/appregistry.html#getsectionkeys)
- [`getSections`](docs/appregistry.html#getsections)
- [`getRunnable`](docs/appregistry.html#getrunnable)
- [`getRegistry`](docs/appregistry.html#getregistry)
- [`setComponentProviderInstrumentationHook`](docs/appregistry.html#setcomponentproviderinstrumentationhook)


---

# Reference

## Methods

### `registerComponent()`

```javascript
AppRegistry.registerComponent(appKey, componentProvider, [section])
```

Registers an app's root component.

**Parameters:**

| Name | Type | Required | Description |
| - | - | - | - |
| appKey | string | Yes | Application key. |
| componentProvider | function | Yes | A function that returns a React component or element. |
| section | boolean | No | Is this a section? |

---

### `runApplication()`

```javascript
AppRegistry.runApplication(appKey, appParameters)
```

Loads the JavaScript bundle and runs the app.

**Parameters:**

| Name | Type | Required | Description |
| - | - | - | - |
| appKey | string | Yes | Application key. |
| appParameters | any | Yes | Params. |

---

### `unmountApplicationComponentAtRootTag()`

```javascript
AppRegistry.unmountApplicationComponentAtRootTag(rootTag)
```

Stops an application when a view should be destroyed. The `rootTag` should match the tag that was passed into `runApplication()`. These should always be used as a pair.

**Parameters:**

| Name | Type | Required | Description |
| - | - | - | - |
| rootTag | number | Yes | React tag. |

---

### `registerHeadlessTask()`

```javascript
AppRegistry.registerHeadlessTask(taskKey, task)
```

Register a headless task. A headless task is a bit of code that runs without a UI.

**Parameters:**

| Name | Type | Required | Description |
| - | - | - | - |
| taskKey | string | No | The key associated with this task. |
| task | function | No | A promise returning function that takes some data passed from the native side as the only argument; when the promise is resolved or rejected the native side is notified of this event and it may decide to destroy the JS context. |


---

### `startHeadlessTask()`

```javascript
AppRegistry.startHeadlessTask(taskId, taskKey, data)
```

Only called from native code. Starts a headless task.

**Parameters:**

| Name | Type | Required | Description |
| - | - | - | - |
| taskId | number | No | The native id for this task instance to keep track of its execution. |
| taskKey | string | No | The key for the task to start. |
| data | any | No | The data to pass to the task. |


---


### `setWrapperComponentProvider()`

```javascript
AppRegistry.setWrapperComponentProvider(provider)
```



---

### `registerConfig()`

```javascript
AppRegistry.registerConfig(config)
```



---

### `registerRunnable()`

```javascript
AppRegistry.registerRunnable(appKey, run)
```



---

### `registerSection()`

```javascript
AppRegistry.registerSection(appKey, component)
```



---

### `getAppKeys()`

```javascript
AppRegistry.getAppKeys()
```



---

### `getSectionKeys()`

```javascript
AppRegistry.getSectionKeys()
```



---

### `getSections()`

```javascript
AppRegistry.getSections()
```



---

### `getRunnable()`

```javascript
AppRegistry.getRunnable(appKey)
```



---

### `getRegistry()`

```javascript
AppRegistry.getRegistry()
```



---

### `setComponentProviderInstrumentationHook()`

```javascript
AppRegistry.setComponentProviderInstrumentationHook(hook)
```