To get started building your own snaps, you must install the MetaMask Flask browser extension.
Install the MetaMask Flask browser extension
MetaMask Flask is an experimental playground that provides developers access to upcoming MetaMask features. It is available as a browser extension.
While a small set of audited snaps are allowlisted in the stable version of the MetaMask browser extension, MetaMask Flask is intended for developers building and testing snaps locally or from npm. Also, new Snaps API features are enabled in Flask for testing and developer feedback before they're enabled in MetaMask stable.
Install the Metamask Flask browser extension in a new browser profile, or disable any existing installed versions of MetaMask before installing Flask. Running multiple instances of MetaMask in the same browser profile breaks dapp interactions.