The world of blockchain and smart contracts is evolving at an unprecedented pace. CONTRACT_ADDRESS_LOG_EVENT notifications offer a powerful way to stay informed about specific smart contract events in real-time. By utilizing this feature, you can enhance security, streamline data analysis, improve user experience, and maintain flexibility in your monitoring approach. If you're a developer or business involved in the blockchain space, it's time to harness the power of these webhook notifications to optimize your dApp or service.

How to do it?

import { TatumSDK, Ethereum, Network } from '@tatumio/tatum'

(async () => {
    const tatum = await TatumSDK.init<Ethereum>({network: Network.ETHEREUM})
    
    const monitoredContractAddress = '0xF64E82131BE01618487Da5142fc9d289cbb60E9d'
    
    const monitoredEvent = '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef'
    
    const subscription = await tatum.notification.subscribe.contractAddressLogEvent({
        contractAddress: monitoredContractAddress,
        event: monitoredEvent,
        url: 'https://<YOUR_WEBHOOK_URL>' // replace with your handler URL
    })
    console.log(`Now you will be notified about all monitored event calls on ${monitoredContractAddress}`)
})()

curl -i -X POST \
  https://api.tatum.io/v4/subscription?type=mainnet \
  -H 'Content-Type: application/json' \
  -H 'x-api-key: <YOUR-API-KEY>' \
  -d '{
    "type": "CONTRACT_ADDRESS_LOG_EVENT",
    "attr": {
      "contractAddress": "0xF64E82131BE01618487Da5142fc9d289cbb60E9d",
      "chain": "ETH",
      "event": "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
      "url": "https://<YOUR_WEBHOOK_URL>"
    }
  }'

What does the fired webhook look like?

The fired notification webhook you will receive in your webhook listener will have the following format.

{
  "events": [
    {
      "txId": "0x7d3dda0430471fe460c07b1ecab35670ef4ce85b",
      "logIndex": 1,
      "timestamp": 1620914417,
      "address": "0x7D3Dda0430471Fe460C07b1ecaB35670eF4ce85b",
      "topic_0": "0x4e3275a5d28e4f6383a4f74592ac9e2f1d0331bde8f7f25cf47d4b15323a47b8",
      "topic_1": "0x000000000000000000000000f64e82131be01618487da5142fc9d289cbb60e9d",
      "topic_2": "0x000000000000000000000000690b9a9e9aa1c9db991c7721a92d351db4fac990",
      "data": "0x0000000000000000000000000000000000000000000000000000000000000064"
    }
  ],
  "blockNumber": 110827114,
  "chain": "ethereum-mainnet",
  "subscriptionType": "CONTRACT_ADDRESS_LOG_EVENT"
}

Which blockchain networks are supported?

Blockchain	Mainnet	Testnet
Ethereum	Network.ETHEREUM	Network.ETHEREUM_SEPOLIA, Network.ETHEREUM_HOLESKY
Polygon	Network.POLYGON	Network.POLYGON_MUMBAI
Binance Smart Chain	Network.BINANCE_SMART_CHAIN	Network.BINANCE_SMART_CHAIN_TESTNET
Flare	Network.FLARE	Network.FLARE_COSTON, Network.FLARE_COSTON_2, Network.FLARE_SONGBIRD
Celo	Network.CELO	Network.CELO_ALFAJORES
Klaytn	Network.KLAYTN	Network.KLATN_BAOBAB
Tezos	Network.Tezos	Network.TEZOS_TESTNET