Function Calls

Decode and store transaction calldata for specific function selectors.

Configuration

Add a [[contracts.calls]] block under any contract that has an ABI with function definitions.

sieve.toml

[[contracts]]
name = "USDC"
address = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"
abi = "abis/erc20.json"
start_block = 21_000_000

[[contracts.calls]]
name = "transfer"
table = "usdc_transfer_calls"
context = ["block_timestamp", "tx_from"]
columns = [
  { param = "to",    name = "to_address", type = "text" },
  { param = "value", name = "value",      type = "numeric" },
]

name · required function name from the ABI

table · required PostgreSQL table name

context · optional same context fields as events

columns · optional auto-generated from ABI function inputs if omitted

How it works

Sieve matches the first 4 bytes of each transaction's input data against the function selector derived from your ABI. When a match is found, the full calldata is decoded and written to your table.

▸ Only successful (non-reverted) transactions are indexed

▸ Columns map to function input parameters, not return values

▸ Can be combined with events on the same contract

Next steps

▸ Native Transfers track ETH transfers without an ABI

▸ Context fields reference all available metadata columns