Monitor an Ethereum Addresses with Python & .mp3 Alerts

There are many many interesting wallets on public blockchains. Think big trading firms, exchanges, hackers, NFT creators.. Being able to watch these wallets in real time, noticing their every move, is very powerful. Here we will make a short script to alert us of ethereum transactions coming from a particular account/address. With transaction alerts we can quickly decide whether to take actions such as: copy trading a good trader, shorting a coin that's about to get doomped, or buy NFTs similar to a collector's new purchase. This will provide a foundation for later on, where we try automated trading based on on-chain events. If you haven't already been interested in trawling through high value or perculiar transactions on etherscan, then this isnt for you.

There are two main ways to interact with Ethereum using python:

  1. web3 module connected to infura API
  2. etherscan API
Web3 Python module is far more versitile, giving us an interface to the Ethereum network (ability to make transactions etc). But for now, the Etherscan API is great for quickly smashing bits of code together quickly.


The idea is basic, we refresh the transactions of a wallet every x seconds. Whenever there is a new transaction, we play a sound or alert. Let's use the etherscan API to fetch the transactions of an address:

import requests

def get_txns(address, block):
    etherscan_url = f'{address}&startblock={block}&sort=asc&apikey={API_KEY}'
    resp = requests.get(etherscan_url).json()['result']
    return resp


Now, `get_txns(address, block)` will get any 'Normal' transactions since block. Note you can change this URL endpoint to fetch internal or token transactions if you so desire. Now to set up an alert for new transactions, let's put it in a loop:

import time

while True:
    txns = get_txns("0x5b5b487aed7d18ac677c73859270b0f6cf5bb69c", 0)


Here we are just checking out the transactions from some address "0x5b5b487aed7d18ac677c73859270b0f6cf5bb69c" since block 0, and display using pretty print so there isnt JSON spam everywhere (v useful).
Now we want to play an alert if there are no transactions since some block, ie `len(txns) == 0`. On UNIX can play an mp3 or sound (windows plebs) with something like:

def beep():
    # we play a file with a `mpg123` command, opening a subprocess, then closing it.
    cmd = "mpg123 ./alert.mp3"
    # we play the sound 3 times
    for i in range(3):
        p = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True)

import winsound
def winbeep():
    winsound.Beep(2500, 100)


Now we have:

while True:
    txns = get_txns("0x5b5b487aed7d18ac677c73859270b0f6cf5bb69c", 0)
    if len(txns) != 0:



That's it. Click here for full script.

Some difference included in script above:

  1. This code is using the Etherscan URL endpoint to watch for token transactions only, not all transactions.
  2. Filters transactions based on who was the sender. In many cases you don't really care if someone is a recipient of a transaction, you only care if they are the sender.
  3. Take the block height of most recent transaction, and then call `get_txns` from that block+1 onwards, so new transactions are only shown once. You could constantly run multiple instances of the program with different sounds alonside oneanother.
If you learnt something or this gets you some α, please support: BTC: bc1q64qjl9fs9fqutx5krmwsh0j78pfmzj4rxevapw XMR: 8BctFibTfaefTA71ZAJt27b6k58Egc4D2LQbGn18AtKT1sTo5jDu8nXeyA6bRV2NK3LRdRidrffDrZsYJnDCdRhbCnG97FS

usage: Watch ERC-20 send txs from an address and sound alarms [-h] -a ADDRESS [-b BLOCK]

optional arguments:
-h, --help            show this help message and exit
-a ADDRESS, --address ADDRESS
                Watch address
-b BLOCK, --block BLOCK
                Start block, send txs after this block height will sound the alarm.