Smart Contract Event Monitors

Monitor events from ERC standards and popular DeFi protocols. Get real-time alerts when critical on-chain events occur.

An event monitor watches a contract address on a supported EVM chain and fires when the event you named is emitted. Typical uses are Transfer on an ERC-20 or ERC-721, Swap on a DEX, or a protocol-specific log such as a liquidation. You pick the chain, the contract, and the event; Chainitor reads public logs and delivers the alert over email, Slack, Telegram, PagerDuty, or a webhook. No private key is required. Browse the standards and protocols below, then create the monitor in the app.

ERC Token Standards

Monitor standard events from widely-used token interfaces

ERC20 Token Standard

Standard interface for fungible tokens on Ethereum and EVM chains

Transfer Approval

ERC721 NFT Standard

Standard interface for non-fungible tokens (NFTs)

Transfer Approval ApprovalForAll

ERC1155 Multi-Token Standard

Standard interface for contracts managing multiple token types

TransferSingle TransferBatch ApprovalForAll

DeFi Protocols

Monitor events from leading decentralized finance protocols

Uniswap V2

Automated market maker (AMM) protocol for token swaps

Swap Mint Burn

Uniswap V3

Concentrated liquidity AMM protocol with improved capital efficiency

Swap Mint

Aave V3

Decentralized lending and borrowing protocol

Supply Borrow LiquidationCall

How an event monitor works

  1. Choose the chain and enter the contract address and event signature.
  2. Optionally add the event ABI and parameter filters: equals, not equals, greater or less than (or equal), and contains.
  3. At each check, Chainitor reads the contract's logs since the previous check and keeps the events that match.
  4. If any matched, you get one alert for that check, by email, Slack, Telegram, PagerDuty or webhook. It names the event signature and the contract and says how many matching events were found.

Example: large USDC transfers out of a treasury

Chain
Ethereum
Contract
0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 (USDC)
Event
Transfer(address,address,uint256)
Filters
from equals 0x1111111111111111111111111111111111111111 (placeholder); value greater than 1000000000000 (1,000,000 USDC at 6 decimals)

Frequently asked questions

What do I need to set up an event monitor?

The contract address, the chain, and the event signature, for example Transfer(address,address,uint256). To filter on the event's parameters, such as only transfers to one address or above an amount, also paste the event's ABI so Chainitor can decode them.

Does an event monitor catch events triggered through a multisig or another contract?

Yes. Events are read from the contract's logs, so it does not matter whether the call came directly from a wallet, through a Safe, a timelock or a router. This is the main difference from a function call monitor, which sees only transactions sent straight to the contract.

How often are alerts sent?

Every check that finds new matching events sends an alert summarising them. Checks run every 5 minutes on Starter and as often as every minute on Pro. Event monitors are on every plan.

Related monitors and guides

Start monitoring smart contract events

Set up event alerts in under 2 minutes. No code required.