Switch Metamask Network to chain 1 (Ethereum Mainnet)

Question

This past week Metamask introduced a new function called "wallet_addEthereumChain" which allows the user to automatically add a new Etheruem RPC to their wallet when prompted. This function also allows the user to change the network they are connected to, for example, if I already have Binance Smart Chain connected to metamask, calling wallet_addEthereumChain changes the active network to BSC. However, when trying this for the Ethereum chain, it gives an error that you cannot add mainnet RPC. I have used the following code to change to change from Ethereum Mainnet to Binance Smart Chain, and it works fine: switchToBinance: async function () {

        let ethereum = window.ethereum;
        const data = [{
            chainId: '0x38',
            chainName: 'Binance Smart Chain',
            nativeCurrency:
                {
                    name: 'BNB',
                    symbol: 'BNB',
                    decimals: 18
                },
            rpcUrls: ['https://bsc-dataseed.binance.org/'],
            blockExplorerUrls: ['https://bscscan.com/'],
        }]
        /* eslint-disable */
        const tx = await ethereum.request({method: 'wallet_addEthereumChain', params:data}).catch()
        if (tx) {
            console.log(tx)
        }
    },

However when I try the Exact thing, metamask throws an exception saying I cannot add a mainnet RPC: switchToEthereum: async function () {

        let ethereum = window.ethereum;
        const data = [{
      chainId: '0x1',
      chainName: 'Ethereum',
      nativeCurrency: {
        name: 'Ethereum',
        symbol: 'ETH',
        decimals: 18,
      },
      rpcUrls: ['https://mainnet.infura.io/v3/undefined'],
      blockExplorerUrls: ['https://etherscan.io'],
    }]
        /* eslint-disable */
        const tx = await ethereum.request({method: 'wallet_addEthereumChain', params:data}).catch()
        if (tx) {
            console.log(tx)
        }
    },

However, the request for adding a new RPC connection, and changing the active RPC connection is the same. So is there a way to change the active Ethereum provider from a custom chain to Mainnet (chain ID-1)

Answer 1

as this issue comment point, for security reason wallet_addEthereumChain not support mainnet. But there a new EIP to resolve this issue, follow EIP-3326 to find release info, and this discuss to see draft progrss.

Answer 2

chainId: '0x38' // error because await not decimal 

Number('0x38').toString(10) //56 - chain ID of BSC

Right:

chainId: `0x${Number(56).toString(16)}`

OR:

chainId: `0x86`

Answer 3

Simply you have to prefix 0x with the chainId.

Example:

 await ethereum.request({
    method: 'wallet_switchEthereumChain',
    params: [{ chainId: '0x1' }],
 })