---
id: react-native
title: Building a React Native Plugin
---

<div class="warning">

This tutorial requires React Native 0.62 or higher.

</div>

Once you have connected Flipper to a React Native application,
writing your own Flipper plugin can be done without reaching into the native world.

To expose Flipper to the JavaScript world, the React Native Native Module `react-native-flipper` needs to be installed in the hosting application by running `yarn add react-native-flipper`. If you are creating develop a plugin that is distributed as NPM package, make sure to add this to the installation instruction of your package as well!

Registering a new plugin is done by importing `addPlugin` from `"react-native-flipper"` and providing it an object that at least implements the method  `getId` (the plugin id that should be used in the desktop plugin as well to make the connection) and two event handlers for the `onConnect` and `onDisconnect` events.

These `onConnect` and `onDisconnect` events are triggered every time the plugin becomes (in)active in the Flipper desktop application.
If the plugin is a [background plugin](../extending/create-plugin.md#background-plugins), these events are triggered typically only once (they might be triggered never, if the Desktop user didn't enable the plugin, or multiple times if they enabled or disabled the plugin a few times).

The `onConnect` callback receive a `connection` which can be used to communicate with the backend:

```javascript
import {addPlugin} from "react-native-flipper"

addPlugin({
  getId() {
    return 'ReactNativeExamplePlugin';
  },
  onConnect(connection) {
    mammmals.forEach(({ title, pictureUrl }, index) => {
      connection.send('newRow', {
          id: index,
          title,
          url: pictureUrl
      })
    })
  },
  onDisconnect() {
  }
})
```

You might want to store the connection somewhere to be able to send more events as long as `onDisconnect` event hasn't been fired.

The `connection` object can also be used to listen to messages coming from the Desktop plugin. See [Client Plugin API](create-plugin) for details.

An example plugin to play a little Tic-Tac-Toe between the Flipper Desktop and a React Native app can be found inside this repository as well (run `yarn && yarn android` in `react-native/ReactNativeFlipperExample` to start the test project):

 * The React Native JavaScript based plugin implementation: [FlipperTicTacToe.js](https://github.com/facebook/flipper/tree/master/react-native/ReactNativeFlipperExample/FlipperTicTacToe.js)
 * The Flipper Desktop plugin implementation: [rn-tic-tac-toe/index.tsx](https://github.com/facebook/flipper/blob/master/desktop/plugins/rn-tic-tac-toe/index.tsx)