blockchain//wallet//Metamask

Metamask is a browser extension that injects an `ethereum` object into the DOM of every web page. Calling `ethereum.request({ method: 'eth_requestAccounts' })` triggers Metamask's approval popup.

Metamask is a browser extension that injects an ethereum object into the DOM of every web page. Calling ethereum.request({ method: 'eth_requestAccounts' }) triggers Metamask's approval popup.

Metamask is not a node. It is a light client that delegates blockchain queries to an RPC endpoint (Infura by default). The password encrypts the seed phrase in the browser's local storage; unlocking decrypts it, and the keys are then derived on the fly, so signing happens locally and the private key never leaves the extension. Switching networks means changing the RPC URL and the chainId, which tell Metamask where to send and which chain to sign for.