MetaMask is a mobile wallet that provides easy access to websites that use the Ethereum blockchain.

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To learn how to develop MetaMask-compatible applications, visit our Developer Docs.

The code is built using React-Native and running code locally requires a Mac or Linux OS.

• Install sentry-cli tools: brew install getsentry/tools/sentry-cli

• Install Node.js version 14 (latest stable) and yarn@1 (latest)

  • If you are using nvm (recommended) running nvm use will automatically choose the right node version for you.

• Install yarn

• Install the shared React Native dependencies (React Native CLI, not Expo CLI)

• Install cocoapods by running:

sudo gem install cocoapods

• Install the Android SDK, via Android Studio.
  • MetaMask Only: To create production builds, you need to install Google Play Licensing Library via the SDK Manager in Android Studio.
• Install the Android NDK, via Android Studio's SDK Manager.
  • In the SDK Manager, select the SDK Tools tab and install NDK version 21.4.7075529. You'll need to click "Show Package Details" in order to select the appropriate version.
• Linux only:
  • Ensure that you have the secret-tool binary on your machine.
    • Part of the libsecret-tools package on Debian/Ubuntu based distributions.
• Install the correct emulator
  • Follow the instructions at:
    • React Native Getting Started - Android (React Native CLI Quickstart -> [your OS] -> Android)
    • More details can be found on the Android Developer site
  • You should use the following:
    • Android OS Version: Latest, unless told otherwise
    • Device: Google Pixel 3
• Finally, start the emulator from Android Studio, and run:

• Install the iOS dependencies
  • React Native Getting Started - iOS (React Native CLI Quickstart -> [your OS] -> iOS)
    • You do not need CocoaPods
• Install the correct simulator
  • iOS OS Version: Latest, unless told otherwise
  • Device: iPhone 11 Pro

• Clone this repo:

git clone ...
cd metamask-mobile

• MetaMask Only: Rename the .*.env.example files (remove the .example) in the root of the project and fill in the appropriate values for each key. Get the values from another MetaMask Mobile developer.
• Non-MetaMask Only: In the project root folder run

  cp .ios.env.example .ios.env && \
  cp .android.env.example .android.env && \
  cp .js.env.example .js.env

• Non-MetaMask Only: Create an account and generate your own API key at Infura in order to connect to main and test nets. Fill MM_INFURA_PROJECT_ID in .js.env. (App will run without it, but will not be able to connect to actual network.)

• Install the app:

yarn setup # not the usual install command, this will run a lengthy postinstall flow
cd ios && pod install && cd .. # install pods for iOS

• Then, in one terminal, run:

yarn watch

yarn start:android

yarn start:ios

Unfortunately, the build system may fail to pick up local changes, such as installing new NPM packages or yarn linking a dependency. If the app is behaving strangely or not picking up your local changes, it may be due to build issues. To ensure that you're starting with a clean slate, close all emulators/simulators, stop the yarn watch process, and run:

yarn clean

# if you're going to `yarn link` any packages,
# do that here, before the next command

yarn watch:clean

# ...and then, in another terminal

yarn start:ios

# or

yarn start:android

If yarn link fails after going through these steps, try directly yarn adding the local files instead.

First, make sure you have the following running:

• yarn watch
• Your Android emulator or iOS simulator
• yarn start:android or yarn start:ios

Next, install the Flipper desktop app (verified working with v0.127.0)

• Once Flipper is installed, configure your system as follows:
  • Install react-devtools: npm i -g [email protected]
  • Update Android SDK location settings by accessing Flipper's settings via the Gear Icon -> Settings
    • Example SDK path: /Users/<USER_NAME>/Library/Android/sdk

Finally, check that the debugger is working:

• Open your emulator or simulator alongside the Flipper app
• Flipper should auto-detect the device and the application to debug
• You should now be able to access features such as Logs

• Debugging physical iOS devices requires idb to be installed, which consists of 2 parts
• Install the two idb parts:
  1. brew tap facebook/fb & brew install idb-companion
  2. pip3.9 install fb-idb (This step may require that you install python3 via python -m pip3 install --upgrade pip)

Android

• Run the app in debug mode (for example, in a simulator)
• Open Chrome on your desktop
• Go to chrome://inspect/#devices
• Look for the device and click inspect

iOS

• Run the app in debug mode (for example, in a simulator)
• Open Safari on your desktop
• Go to the menu Develop -> [Your device] -> [Website]

You should see the console for the website that is running inside the WebView

• Troubleshooting for React Native
• Flipper Documentation

yarn test:unit

First, follow the instructions here to install applesimutils. Then:

yarn test:e2e:ios

yarn test:e2e:android

Whenever you change dependencies (adding, removing, or updating, either in package.json or yarn.lock), there are various files that must be kept up-to-date.

• yarn.lock:
  • Run yarn setup again after your changes to ensure yarn.lock has been properly updated.
• The allow-scripts configuration in package.json
  • Run yarn allow-scripts auto to update the allow-scripts configuration automatically. This config determines whether the package's install/postinstall scripts are allowed to run. Review each new package to determine whether the install script needs to run or not, testing if necessary.
  • Unfortunately, yarn allow-scripts auto will behave inconsistently on different platforms. macOS and Windows users may see extraneous changes relating to optional dependencies.

To get a better understanding of the internal architecture of this app take a look at this diagram.

We have begun documenting our components using storybook please read the Documentation Guidelines to get up and running.