Firmware versions M-5.0 (Multi-Coin) or newer will allow you to use the MetaMask Extension (V10.8.0 or newer) with your Keystone and set the extension as a watch-only wallet on your Keystone Essential or Pro.
1. Firmware versions M-5.0 (Multi-Coin) or newer running on Keystone Essential or Pro.
2. Download the MetaMask browser extension (V10.8.0 or newer) from MetaMask's official website.
A wallet generated by MetaMask has its recovery phrase online. This means that this recovery phrase has been connected to the network(internet).
Therefore, even if you import this recovery phrase created by MetaMask into Keystone (or any other hardware wallets) to continue managing your digital assets, this recovery phrase might already be at the risk of being attacked by hackers.
In principle, we highly recommend creating a new recovery phrase (new wallet with a 24-word seed phrase) offline on a Keystone hardware wallet and then transferring your assets from your MetaMask wallet to the new one prior to using your Keystone to interact with MetaMask. This is the safest way to protect your assets.
III. Bind MetaMaskwith your Keystone Hardware Wallet
1. Set Up Your MetaMask
1) If you are running any fork of MetaMask other than the standard production fork, disable it now.
2) Run the “MetaMask Extension”. Click on [Get Started] to begin setting up your MetaMask.
3) Choose to either create a new MetaMask wallet or import one. Here we will create a new Secret Recovery Phrase as a demonstration.
4) Set up your password. Please try to set a strong password to maximize the security for your account.
5) Keep your secret recovery phrase somewhere safe.
6) Now you have successfully set up your MetaMask. Feel free to browse around the MetaMask mainpage to familiarize yourself with it.
2. Connect MetaMask to Your Keystone
1) Keystone: Tap the "Menu" icon > then Tap [Software Wallet] > then Select [MetaMask / Defi / Web3] and Tap [Confirm] on the Keystone device.
2) tap the icon on the top right corner of the toolbar > then select [Connect Software Wallet] > then choose the accounts that you are going to import and tap [Confirm].
3) MetaMask: Click on the "Menu" icon on the top right corner > then select [Connect Hardware Wallet].
4) Select [QR-based] and then click [Continue].
5) MetaMask uses your computer's camera to scan the QR code displayed on the Keystone hardware wallet.
6) Select the Account that you want to bind and click [Unlock].
7) MetaMask should now be successfully bound to your Keystone.
IV. Sending ETH (Mainnet) Using MetaMask Extension
1. Generate an ETH transaction with your MetaMask.
a. Click on [send], then enter the associated address in [send to address], don’t forget to also set your desired [amount], then click [Next].
b. You can adjust the transaction fee to the limit you’re comfortable with by selecting  > [Advanced Option].
Max priority fee (aka “miner tip”) goes directly to miners and incentivizes them to prioritize your transaction. You’ll often pay the maximum amount set.
The max fee is the total, global amount paid for your transaction (base fee + priority fee).
c. Click on [Confirm] after confirming all the transaction details, then get the unsigned transaction in QR code format.
2. Using your Keystone Hardware Wallet to Sign Transactions
a. In MM / Defi / Web3 mode, touch the “scan” icon on the top right of your Keystone hardware wallet’s main page, then scan the QR code displayed on the MetaMask interface.
b. After confirming the transaction information, press [Sign] and enter your password or fingerprint to sign the transaction to get the signed transaction information in QR code format.
3. Broadcasting the transaction with your MetaMask
a. Click on [Get Signature] on the MetaMask interface and scan the QR code displayed on your Keystone hardware wallet. Once the scan is completed, the transaction will be broadcasted directly onto the ETH blockchain.