MetaMask Browser Extension

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

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 10 and the latest available npm@6
  • If you are using nvm (recommended) running nvm use will automatically choose the right node version for you.
  • If you install Node.js manually, ensure you're using npm@6
    • Install npm@6 using npm install -g npm@6
• Install dependencies: npm ci
  • If you have issues with node-sass compilation, try npm rebuild node-sass
• Build the project to the ./dist/ folder with npm run dist.
• Optionally, to start a development build (e.g. with logging and file watching) run npm start instead.
  • To start the React DevTools and Redux DevTools Extension alongside the app, use npm run 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 (shown in the context menu and in the extension menu) to access Redux state logs.
      • 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

You can read our internal docs here.

You can re-generate the docs locally by running npm run doc, and contributors can update the hosted docs by running npm run publish-docs.

Running Tests

Run tests with npm test.

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

You can run the linter by itself with npm run lint.

Architecture

Development

npm install
npm start

Build for Publishing

npm run dist

Writing Browser Tests

To write tests that will be run in the browser using QUnit, add your test files to test/integration/lib.

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
• The MetaMask Team
• How to live reload on local dependency changes
• How to add new networks to the Provider Menu
• How to port MetaMask to a new platform
• How to use the TREZOR emulator
• How to generate a visualization of this repository's development