Send ETH using ethersjs without private key

Question

Most tutorials I googled need wallet's private key to send ETH, such as this. How can we send ETH without knowing the private key using ethersjs? So, that user can just call their MetaMask and send.

Answer 1

You can use the Signer#sendTransaction method after getting the signer of the MetaMask provider:

async function sendEth (receiver, weiAmount) { 
  const provider = new ethers.providers.Web3Provider(window.ethereum)
  const signer = provider.getSigner()
  const tx = await signer.sendTransaction({
      to: receiver,
      value: weiAmount
  })
  return tx.hash
}

await sendEth('0x12345...', ethers.utils.parseEther('0.12345'))

Answer 2

I am not sure I understand what you mean by user can just call their MetaMask and send.

However, in any case, it is not possible at all to send a transaction without having the private key of the sender.

Compare it to real life scenario: Would you think it is secured to be able to use a credit card without knowing its four digit code ? (yes, I am looking at you contactless payment, heresy)