This page will help you install and build your first React Native app. If you already have React Native installed, you can skip ahead to the [Tutorial](docs/tutorial.html).
[Create React Native App](https://github.com/react-community/create-react-native-app) is the easiest way to start building a new React Native application. It allows you to start a project without installing or configuring any tools to build native code - no Xcode or Android Studio installation required (see [Caveats](docs/getting-started.html#caveats)).
Assuming that you have [Node](https://nodejs.org/en/download/) installed, you can use npm to install the `create-react-native-app` command line utility:
Install the [Expo](https://expo.io) client app on your iOS or Android phone and connect to the same wireless network as your computer. Using the Expo app, scan the QR code from your terminal to open your project.
Now that you have successfully run the app, let's modify it. Open `App.js` in your text editor of choice and edit some lines. The application should reload automatically once you save your changes.
- Create React Native App also has a [user guide](https://github.com/react-community/create-react-native-app/blob/master/react-native-scripts/template/README.md) you can reference if you have questions specific to the tool.
- If you can't get this to work, see the [Troubleshooting](https://github.com/react-community/create-react-native-app/blob/master/react-native-scripts/template/README.md#troubleshooting) section in the README for Create React Native App.
If you're curious to learn more about React Native, continue on
to the [Tutorial](docs/tutorial.html).
### Running your app on a simulator or virtual device
Create React Native App makes it really easy to run your React Native app on a physical device without setting up a development environment. If you want to run your app on the iOS Simulator or an Android Virtual Device, please refer to the instructions for building projects with native code to learn how to install Xcode and set up your Android development environment.
Once you've set these up, you can launch your app on on an Android Virtual Device by running `npm run android`, or on the iOS Simulator by running `npm run ios` (macOS only).
Because you don't build any native code when using Create React Native App to create a project, it's not possible to include custom native modules beyond the React Native APIs and components that are available in the Expo client app.
If you know that you'll eventually need to include your own native code, Create React Native App is still a good way to get started. In that case you'll just need to "[eject](https://github.com/react-community/create-react-native-app/blob/master/react-native-scripts/template/README.md#ejecting-from-create-react-native-app)" eventually to create your own native builds. If you do eject, the "Building Projects with Native Code" instructions will be required to continue working on your project.
Create React Native App configures your project to use the most recent React Native version that is supported by the Expo client app. The Expo client app usually gains support for a given React Native version about a week after the React Native version is released as stable. You can check [this document](https://github.com/react-community/create-react-native-app/blob/master/VERSIONS.md) to find out what versions are supported.
If you're integrating React Native into an existing project, you'll want to skip Create React Native App and go directly to setting up the native build environment. Select "Building Projects with Native Code" above for instructions on configuring a native build environment for React Native.
<blockclass="native mac windows linux ios android"/>
<p>Follow these instructions if you need to build native code in your project. For example, if you are integrating React Native into an existing application, or if you "ejected" from <ahref="docs/getting-started.html"onclick="displayTab('guide', 'quickstart')">Create React Native App</a>, you'll need this section.</p>
The instructions are a bit different depending on your development operating system, and whether you want to start developing for iOS or Android. If you want to develop for both iOS and Android, that's fine - you just have to pick
<blockquote><p>A Mac is required to build projects with native code for iOS. You can follow the <ahref="docs/getting-started.html"onclick="displayTab('guide', 'quickstart')">Quick Start</a> to learn how to build your app using Create React Native App instead.</p></blockquote>
While you can use any editor of your choice to develop your app, you will need to install Xcode in order to set up the necessary tooling to build your React Native app for iOS.
While you can use any editor of your choice to develop your app, you will need to install Android Studio in order to set up the necessary tooling to build your React Native app for Android.
If you have already installed Node on your system, make sure it is version 4 or newer.
[Watchman](https://facebook.github.io/watchman) is a tool by Facebook for watching changes in the filesystem. It is highly recommended you install it for better performance.
React Native also requires a recent version of the [Java SE Development Kit (JDK)](http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html), as well as Python 2. Both can be installed using Chocolatey.
If you have already installed Node on your system, make sure it is version 4 or newer. If you already have a JDK on your system, make sure it is version 8 or newer.
The easiest way to install Xcode is via the [Mac App Store](https://itunes.apple.com/us/app/xcode/id497799835?mt=12). Installing Xcode will also install the iOS Simulator and all the necessary tools to build your iOS app.
If you have already installed Xcode on your system, make sure it is version 8 or higher.
You will also need to install the Xcode Command Line Tools. Open Xcode, then choose "Preferences..." from the Xcode menu. Go to the Locations panel and install the tools by selecting the most recent version in the Command Line Tools dropdown.
React Native requires a recent version of the Java SE Development Kit (JDK). [Download and install JDK 8 or newer](http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html) if needed.
Setting up your development environment can be somewhat tedious if you're new to Android development. If you're already familiar with Android development, there are a few things you may need to configure. In either case, please make sure to carefully follow the next few steps.
[Download and install Android Studio](https://developer.android.com/studio/index.html). Choose a "Custom" setup when prompted to select an installation type. Make sure the boxes next to all of the following are checked:
Android Studio installs the latest Android SDK by default. Building a React Native app with native code, however, requires the `Android 6.0 (Marshmallow)` SDK in particular. Additional Android SDKs can be installed through the SDK Manager in Android Studio.
> The SDK Manager can also be found within the Android Studio "Preferences" dialog, under **Appearance & Behavior** → **System Settings** → **Android SDK**.
Select the "SDK Platforms" tab from within the SDK Manager, then check the box next to "Show Package Details" in the bottom right corner. Look for and expand the `Android 6.0 (Marshmallow)` entry, then make sure the following items are all checked:
Next, select the "SDK Tools" tab and check the box next to "Show Package Details" here as well. Look for and expand the "Android SDK Build-Tools" entry, then make sure that `23.0.1` is selected.
Type `source $HOME/.bash_profile` to load the config into your current shell. Verify that ANDROID_HOME has been added to your path by running `echo $PATH`.
> Please make sure you use the correct Android SDK path. You can find the actual location of the SDK in the Android Studio "Preferences" dialog, under **Appearance & Behavior** → **System Settings** → **Android SDK**.
Open the System pane under **System and Security** in the Control Panel, then click on **Change settings...**. Open the **Advanced** tab and click on **Environment Variables...**. Click on **New...** to create a new `ANDROID_HOME` user variable that points to the path to your Android SDK:
You can find the actual location of the SDK in the Android Studio "Preferences" dialog, under **Appearance & Behavior** → **System Settings** → **Android SDK**.
Follow the [Watchman installation guide](https://facebook.github.io/watchman/docs/install.html#build-install) to compile and install Watchman from source.
> [Watchman](https://facebook.github.io/watchman/docs/install.html) is a tool by Facebook for watching
changes in the filesystem. It is highly recommended you install it for better performance, but it's alright to skip this if you find the process to be tedious.
This is not necessary if you are integrating React Native into an existing application, if you "ejected" from Create React Native App, or if you're adding iOS support to an existing React Native project (see [Platform Specific Code](docs/platform-specific-code.html)).
This is not necessary if you are integrating React Native into an existing application, if you "ejected" from Create React Native App, or if you're adding Android support to an existing React Native project (see [Platform Specific Code](docs/platform-specific-code.html)).
You will need an Android device to run your React Native Android app. This can be either a physical Android device, or more commonly, you can use an Android Virtual Device which allows you to emulate an Android device on your computer.
If you have a physical Android device, you can use it for development in place of an AVD by plugging it in to your computer using a USB cable and following the instructions [here](docs/running-on-device.html).
You can see the list of available Android Virtual Devices (AVDs) by opening the "AVD Manager" from within Android Studio. Look for an icon that looks like this:
If you have just installed Android Studio, you will likely need to [create a new AVD](https://developer.android.com/studio/run/managing-avds.html). Select "Create Virtual Device...", then pick any Phone from the list and click "Next".
> We recommend configuring [VM acceleration](https://developer.android.com/studio/run/emulator-acceleration.html#vm-linux) on your system to improve performance. Once you've followed those instructions, go back to the AVD Manager.
> If you don't have HAXM installed, click on "Install HAXM" or follow [these instructions](https://software.intel.com/en-us/android/articles/installation-instructions-for-intel-hardware-accelerated-execution-manager-windows) to set it up, then go back to the AVD Manager.
> If you don't have HAXM installed, follow [these instructions](https://software.intel.com/en-us/android/articles/installation-instructions-for-intel-hardware-accelerated-execution-manager-mac-os-x) to set it up, then go back to the AVD Manager.
Click "Next" then "Finish" to create your AVD. At this point you should be able to click on the green triangle button next to your AVD to launch it, then proceed to the next step.
> If you can't get this to work, see the [Troubleshooting](docs/troubleshooting.html#content) page.
### Running on a device
The above command will automatically run your app on the iOS Simulator by default. If you want to run the app on an actual physical iOS device, please follow the instructions [here](docs/running-on-device.html).
`react-native run-android` is just one way to run your app - you can also run it directly from within Android Studio or [Nuclide](https://nuclide.io/).
- Turn on [Live Reload](docs/debugging.html#reloading-javascript) in the Developer Menu. Your app will now reload automatically whenever you save any changes!
- If you want to add this new React Native code to an existing application, check out the [Integration guide](docs/integration-with-existing-apps.html).
- Turn on [Live Reload](docs/debugging.html#reloading-javascript) in the Developer Menu. Your app will now reload automatically whenever you save any changes!
- If you want to add this new React Native code to an existing application, check out the [Integration guide](docs/integration-with-existing-apps.html).
