Here is an article on how to get the private key from Metamask when sending a transaction using web3:
Get the private key from Metamask for Ethereum transactions
When working with Ethereum Smart Contracts using the Web3 bookshop, you probably want to sign transactions using the private key. However, not all users can have their private keys promptly available or accessible via the Metamask portfolio. This is where Metamask is useful.
SIGN A transaction using web3s and the private key
When creating an account with Metamask, you are supplied with two main types of keys:
Accounting keys (or paper wallets) and
Web3 keys (or Metamask keys) . To sign transactions using the private key from Metamask, follow the steps of the thesis:
Step 1: Get the web3 key
If you have already set up a web3 account with Metamask, go to the Dashboard Metamask where you can view the web3 keys. You should see a list of keys available in Json format.
`Json
[
{
"Address": "0x ...",
"Privatekey": "...",
"Publickey": "...",
"Name": "Your name"
},
...
"
In this example, we will call the first Key1 key. The address (0x ...) and the private key (`) are what you will use to sign transactions.
Step 2: Sign a transaction using web3
To sign a transaction using the web3 button, use the following code fragment:
`Javascript
Const Web3 = Requirement (‘Web3’).
// Replace “Yourprivatekey” with the actual private key
Countertemy = “0x …”;
Const TX = {
From: ‘0x …’, // the address of the contract to which you want to send a transaction.
A: ‘0x …’, // the address of the recipient of the transaction.
Value: 100, // the amount of the ether that will be sent to this transaction.
Data: “Your transaction message”. // a description of what the transaction is for.
};
Web3.eth.acounts.signransation (TX, Privatekey, (Error, Firmedtx) => {{{{{
If (error) console.error (error);
Other {
Web3.eth.endssignedtransazion (signadtx.ramransation) .then ((result) => {{{{{{{
Console.log (result);
}).
console.error (error);
});
}
});
`
Example of use case:
Suppose you are trying to send a transaction from your Metamask wallet. You created an account with the metamask dashboard and set a web3 button for that address.
Javascript
Const Web3 = Requirement (‘Web3’).
// Replace “Yourprivatekey” and “0x …” with the private key and the contractual address.
Countertemy = “0x …”; // Replace it with the actual private key.
Constitute address = “0x …”; // Replace this with the address of the intelligent contract to which you want to send a transaction.
Web3.eth.acauts.signransation ({{
From: ‘0x …’, // the address of the contract to which you want to send a transaction.
To: contractual address, // the address of the recipient of the transaction.
Value: 100, // the amount of the ether that will be sent to this transaction.
Data: “Your transaction message”. // a description of what the transaction is for.
}, Privatekey, (Error, signadtx) => {
If (error) console.error (error);
Other {
Web3.eth.endssignedtransazion (signadtx.ramransation) .then ((result) => {{{{{{{
Console.log (result);
}).
console.error (error);
});
}
});
`
In this example, we are signing a transaction using our private key from the Metamask wallet and sending it to the contract address. The signed transaction will be sent to Ethereum in exchange for the specific ether in theValue` field.
I hope this helps! Let me know if you have questions or you need further assistance.