Access cutting-edge innovation and features

MetaMask Flask is a developer-focused distribution of the MetaMask extension where we test and validate experimental features before rolling them out to the stable MetaMask applications. The first feature to be released through Flask is Snaps. Snaps allows web3 developers to expand the functionality of MetaMask at runtime, without our involvement. Since MetaMask is the first wallet to offer extensibility to users, Snaps is poised to accelerate the rate of innovation in not just Ethereum, but the entire web3 ecosystem. You can read more about Snaps here.

Please remember that Flask is a developer tool; its features and APIs are not stable, its UX is not as polished, and we do not guarantee the same level of support as for the stable extension or mobile app. Flask gives you access to our most cutting edge features, but you use it at your own risk!

MetaMask is the most popular non-custodial Ethereum wallet in the world. It allows users to manage their Ethereum assets and access web3. Its features and UX are stable and have gone through extensive testing.

MetaMask Flask is the experimental proving ground for our most cutting-edge and innovative features. Flask does not offer the same API or UX stability guarantees as the stable MetaMask applications, and participation is at your own risk.

If you’re not a developer, we recommend you only use the stable MetaMask applications and do not use MetaMask Flask. If you’re a web3 developer and feel adventurous, then MetaMask Flask is for you.

We take the security of MetaMask Flask as seriously as any other MetaMask application, but just like a construction site is less safe than a finished building, there are more risks when using Flask than when using the stable MetaMask applications. For example, Flask’s UX is not as polished, and it allows you to take greater risks than on the stable applications. In addition, because of its experimental nature, its APIs are unstable, and things that worked in one release may be permanently broken in the next.

In short, you can use Flask safely, but it’s easier to use it unsafely. Participation is at your own risk and intended for developers only.

Every asset and network that’s available on the stable MetaMask applications, and whatever developers enable by building snaps! Already, our friends at Protocol Labs and ChainSafe have built a Filecoin snap.

Yes, MetaMask Flask is free to use.

MetaMask Flask is currently only available as a desktop browser extension for Chrome and Firefox.

Snaps is the first feature to be released through Flask.

Snaps allows developers to expand the functionality of MetaMask at runtime, without our involvement. That’s right—you can add your own features and make them available to users, without any involvement from the MetaMask team!

To learn more about Snaps and how to make use of this feature, read our technical documentation.

You can file bugs here. This link is also found in-product in case you run into any bugs while building. Thanks for your support to make our product better.

You can submit feedback about Snaps here. Thank you for helping us make our product better!

MetaMask may develop some snaps, but most snaps are made by the community. For example, our friends at Protocol Labs and ChainSafe have built a Filecoin snap.

You can find everything you need in our technical documentation.

Not yet. For now, you need MetaMask Flask to run snaps.