Smart Contract Event

Trigger Onchain

Triggers when a smart contract emits an on-chain event that matches your filter criteria. Advanced — requires an event ABI.

At a Glance

Field	Value
Trigger ID	evm-log
Category	Onchain
Tags	evm, blockchain, event, log, smart-contract, on-chain, ethereum, advanced

Trigger Configuration

Field	Type	Required	Description
chainId	integer	Yes	Chain ID to subscribe to (e.g., 1 for Ethereum, 42161 for Arbitrum)
contractAddress	string	No	Single contract address to filter events from. Mutually exclusive with contractAddresses. If both are omitted, events from all contracts on the chain are matched.
contractAddresses	array	No	List of contract addresses to watch (up to 20). Mutually exclusive with contractAddress.
eventAbi	object	Yes	Event ABI in Etherscan/Solidity JSON format. Must include 'name', 'type', and 'inputs' fields.
filter	object	No	Filter DSL to match event parameters. Top level MUST be $and or $or. Supports $eq, $ne, $gt, $gte, $lt, $lte, $in, $nin operators.
enrichments	array	No	Additional data to include with each event. Each enrichment adds an RPC call (and sometimes a price lookup) per trigger.
enrichmentFilter	object	No	Filter applied to enrichment results. Only fires when enriched data matches. Same syntax as event filter ($and/$or with $eq, $gt, $gte, $lt, $lte, $in, etc.).

Trigger Result

Field	Type	Required	Description
triggeredAt	string	Yes	Timestamp when the event was detected (UTC, RFC3339 format)
params	object	Yes	Decoded event parameters based on eventAbi. Field names and structure match the ABI definition.
raw	object	Yes	Raw log data including address, topics, data, blockNumber, transactionHash, etc.
enrichments	object	No	Additional data from opt-in enrichments. Only populated when the corresponding enrichment is enabled.

Workflow Root Example

json
{  "nodes": {    "root": {      "type": "evm-log",      "payload": {        "chainId": 8453,        "eventAbi": {          "_comment": "ERC20 Transfer event ABI (matches simple filter/params example)",          "anonymous": false,          "inputs": [            {              "indexed": true,              "internalType": "address",              "name": "from",              "type": "address"            },            {              "indexed": true,              "internalType": "address",              "name": "to",              "type": "address"            },            {              "indexed": false,              "internalType": "uint256",              "name": "value",              "type": "uint256"            }          ],          "name": "Transfer",          "type": "event"        }      },      "children": [        "log_event"      ]    },    "log_event": {      "type": "log",      "payload": {        "message": "Triggered at {{$trigger.triggeredAt}}"      },      "children": []    }  }}

Downstream nodes can use {{$trigger.triggeredAt}} and any result fields listed above. Event triggers usually expose the raw source payload under a field such as event, body, trade, or raw.