MetaMask supports Firefox, Google Chrome, and Chromium-based browsers. We recommend using the latest available browser version.
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.
nvm usewill automatically choose the right node version for you.
yarn setup(not the usual install command)
Uncompressed builds can be found in
/dist, compressed builds can be found in
/builds once they're built.
To start a development build (e.g. with logging and file watching) run
8000, secure connection checkbox unchecked)
Run unit tests and the linter with
To run just unit tests, run
yarn test:unit. To run unit tests continuously with a file watcher, run
You can run the linter by itself with
yarn lint, and you can automatically fix some lint problems with
yarn lint:fix. You can also run these two commands just on your local changes to save time with
yarn lint:changed and
yarn lint:changed:fix respectively.
Our e2e test suite can be run on either Firefox or Chrome. In either case, start by creating a test build by running
Firefox e2e tests can be run with
Chrome e2e tests can be run with
yarn test:e2e:chrome, but they will only work if you have Chrome v79 installed. Update the
chromedriver package to a version matching your local Chrome installation to run e2e tests on newer Chrome versions.
Whenever you change dependencies (adding, removing, or updating, either in
yarn.lock), there are various files that must be kept up-to-date.
yarn setupagain after your changes to ensure
yarn.lockhas been properly updated.
yarn allow-scripts autoto update the
allow-scriptsconfiguration 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.
yarn allow-scripts autowill behave inconsistently on different platforms. macOS and Windows users may see extraneous changes relating to optional dependencies.
yarn lavamoat:autoto re-generate this policy file. Review the changes to determine whether the access granted to each package seems appropriate.
yarn lavamoat:autowill behave inconsistently on different platforms. macOS and Windows users may see extraneous changes relating to optional dependencies.
yarn yarn start