What is the best way to listen to program emitted events in solana?

Question

I come from an EVM background and wonder how to listen to Solana events in my dapp such as token/nft deposits/withdrawals to/from a specific user account, creation of new pools, swaps etc.

I tried solanaConnection.onAccountChange() to catch balance changes. but for non-native token balances, I assume the changes are logged with the AccountInfo.data field but this is a hex buffer and I'm not sure how to convert to a meaningful json.

Another way I came across is https://docs.solana.com/api/websocket#accountsubscribe which seems similar to getAccountInfo() but again facing the conversion of data field from base58 encoding to meaningful json.

i have already tried JSON.parse(buf.toString());

Answer 1

so the easy way is using:

var tokenAccount = new PublicKey("9ursCuiPyhDtD6oNcxPjubev7iSABbqGhvJkMvjncrxE");
getAccount(connection, tokenAccount).then((result) => {
  console.log("getAccountResult: " + JSON.stringify(result));
});

Is you want to parse the data directly when you get it back from onAccountChange web socket connection you can do this:

import { unpackAccount, TOKEN_PROGRAM_ID } from "@solana/spl-token";

        var tokenAccount = new PublicKey("9ursCuiPyhDtD6oNcxPjubev7iSABbqGhvJkMvjncrxE");
connection.onAccountChange(tokenAccount, (account) => {
  var parsedAccount = unpackAccount(tokenAccount, account, TOKEN_PROGRAM_ID);
  console.log("ParsedTokenAccount: " + JSON.stringify(parsedAccount));
}, "confirmed")

This will be triggered every time the token account changes. So when the account increases or decreases for example