Monitoring Pending Transactions

Question

How would I go about monitoring pending transactions in real-time? Would I be able to monitor only one function?

I have a full node running and have a nodejs (express server) that I want to have this info available to.

I am guessing that a websocket would be the way to go, in which case what would I be listening for?

Answer 1

1. You can create a stream of pending transactions using web3.eth.subscribe('pendingTransactions' [, callback]);, which currently returns a transaction hash.
2. You can turn into the actual transaction object using web3.eth.getTransaction(transactionHash [, callback]), which will return a transaction object.
3. You can then filter the returned object by to and input to find only the transactions that are being sent to a specific contract address and are calling a specific function in that contract.

Answer 2

Bit late to the show, but to resolve the getTransaction you need to create a buffer, wait till it gets a few confirmations that way the data is more available.

I would suggest creating a batch call, adding them all then rotate through the batch call for the ones you need.