Most Common web3 Methods to interact with Metamask wallet

The below post highlights quick glimpse of most common method required to interact with Metamask wallet . The libraries provides an interface to invoke the corresponding JSON-RPC-API (Eth Network) which is essential to connect to metamask wallet from web browsers.

1. Check If Metamask exist in browser

?import Web3 from 'web3';
// Quick /Dirty way to find Metamask is installed 
if(window.ethereum)
? ? ? provider=window.ethereum;
? ? }
? ? else{
? ? ? console.log("Metamask not installed");
? ? }{        

2.Check if Metamask wallet is connected to required network (Sepholia,Mainnet etc.. )

onst deductprovider= async ()=>
? ? let provider;
? ? if(window.ethereum){
? ? ? const currentChainId = await window.ethereum.request({
? ? ? ? method: 'eth_chainId',
? ? ? });
? ? ? console.log(currentChainId);
? ? ? if(currentChainId=="0x1"){ // 0x1 is Mainnet , it could be any desired network {
? ? ? provider=window.ethereum;
? ? ? }
? ? ? else{
? ? ? ? console.log(" User wallet is not connected to required Eth Network")
? ? ? } ? ?
? ? }
? ? else{
? ? ? console.log("Metamask is required");
? ? }
? };        

3. Switch/Refresh to any Eth network

const switchNetwork = async () => 
  await window.ethereum.request({
    method: 'wallet_switchEthereumChain',
    params: [{ chainId: '0x01'}],
  });
  // refresh
  window.location.reload();
}        

The highlighted once are quite basic essential to connect/interact with metamask for further user communication with DAPP. It's a quick/common way to get started with interacting to Eth network from front-end.

References :

https://docs.metamask.io/wallet/reference/rpc-api/