MetaMask
MetaMask is a mobile wallet that provides easy access to websites that use the Ethereum blockchain.
For up to the minute news, follow our Twitter or Medium pages.
To learn how to develop MetaMask-compatible applications, visit our Developer Docs.
MetaMask Mobile
Environment Setup
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.
- If you are using nvm (recommended) running
-
Install yarn
-
Install the shared React Native dependencies (
React Native CLI
, notExpo CLI
) -
Install cocoapods by running:
sudo gem install cocoapods
Device Environment Setup
Android
- Install Java. To check if Java is already installed, run:
java -version
- 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 (version
21.4.7075529
), via Android Studio's SDK Manager.- Go to Preferences > Appearance & Behavior > System Settings > Android SDK
- Shortcut: Selecting
More Actions
>SDK Manager
from the "Welcome to Android Studio" page will also bring you here.
- Shortcut: Selecting
- Select
SDK Tools
tab - Locate
NDK (Side-by-side)
option in the tools list - Check
Show Package Details
option below the tools list to show available versions - Check NDK version
21.4.7075529
- Click "Apply" or "OK" to download
- Go to Preferences > Appearance & Behavior > System Settings > Android SDK
- Linux only:
- Ensure that you have the
secret-tool
binary on your machine.- Part of the libsecret-tools package on Debian/Ubuntu based distributions.
- Ensure that you have the
- 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
- Follow the instructions at:
- Finally, start the emulator from Android Studio:
- Open "Virtual Device Manager"
- Launch emulator for "Pixel 3 <relevant API version mentioned in React Native Getting Started>"
iOS
- Install the iOS dependencies
- React Native Getting Started - iOS (React Native CLI Quickstart -> [your OS] -> iOS)
- You do not need CocoaPods
- React Native Getting Started - iOS (React Native CLI Quickstart -> [your OS] -> iOS)
- Install the correct simulator
- iOS OS Version: Latest, unless told otherwise
- Device: iPhone 11 Pro
Building Locally
- 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
Android
yarn start:android
iOS
yarn start:ios
Build Troubleshooting
Unfortunately, the build system may fail to pick up local changes, such as installing new NPM packages or yarn link
ing 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 add
ing the local files instead.
Debugging
First, make sure you have the following running:
yarn watch
- Your Android emulator or iOS simulator
yarn start:android
oryarn 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
- Example SDK path:
- Install react-devtools:
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
- Debugging physical iOS devices requires
idb
to be installed, which consists of 2 parts - Install the two idb parts:
brew tap facebook/fb
&brew install idb-companion
pip3.9 install fb-idb
(This step may require that you install python3 viapython -m pip3 install --upgrade pip
)
Debug a website inside the WebView (in-app browser)
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
Miscellaneous
Running Tests
Unit Tests
yarn test:unit
E2E Tests (iOS)
First, follow the instructions here to install applesimutils
. Then:
yarn test:e2e:ios
E2E Tests (Android)
yarn test:e2e:android
Changing dependencies
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 ensureyarn.lock
has been properly updated.
- Run
- The
allow-scripts
configuration inpackage.json
- Run
yarn allow-scripts auto
to update theallow-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.
- Run
Architecture
To get a better understanding of the internal architecture of this app take a look at this diagram.
Storybook
We have begun documenting our components using storybook please read the Documentation Guidelines to get up and running.