MetaMask Browser Extension

Hey! We are hiring JavaScript Engineers! Apply here!

You can find the latest version of MetaMask on our official website. For help using MetaMask, visit our User Support Site.

For general questions, feature requests, or developer questions, visit our Community Forum.

MetaMask supports Firefox, Google Chrome, and Chromium-based browsers. We recommend using the latest available browser version.

For up to the minute news, follow our Twitter or Medium pages.

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

To learn how to contribute to the MetaMask project itself, visit our Internal Docs.

Building locally

• Install Node.js version 14
  • If you are using nvm (recommended) running nvm use will automatically choose the right node version for you.
• Install Yarn
• Install dependencies: yarn setup (not the usual install command)
• Copy the .metamaskrc.dist file to .metamaskrc
  • Replace the INFURA_PROJECT_ID value with your own personal Infura Project ID.
  • If debugging MetaMetrics, you'll need to add a value for SEGMENT_WRITE_KEY Segment write key.
• Build the project to the ./dist/ folder with yarn dist.
• Optionally, to start a development build (e.g. with logging and file watching) run yarn start instead.
  • To start the React DevTools and Redux DevTools Extension alongside the app, use yarn start:dev.
    • React DevTools will open in a separate window; no browser extension is required
    • Redux DevTools will need to be installed as a browser extension. Open the Redux Remote Devtools to access Redux state logs. This can be done by either right clicking within the web browser to bring up the context menu, expanding the Redux DevTools panel and clicking Open Remote DevTools OR clicking the Redux DevTools extension icon and clicking Open Remote DevTools.
      • You will also need to check the "Use custom (local) server" checkbox in the Remote DevTools Settings, using the default server configuration (host localhost, port 8000, secure connection checkbox unchecked)

Uncompressed builds can be found in /dist, compressed builds can be found in /builds once they're built.

Contributing

Running Tests

Run tests with yarn test.

You can also test with a continuously watching process, via yarn watch.

You can run the linter by itself with yarn lint.

Architecture

Development

yarn
yarn start

Build for Publishing

yarn dist

Other Docs

• How to add custom build to Chrome
• How to add custom build to Firefox
• How to add a new translation to MetaMask
• Publishing Guide
• How to use the TREZOR emulator
• How to generate a visualization of this repository's development