EVM: from a tx hash to the decoded call, logs and revert

⚠️ DANGEROUS: use at your own risk. Code that handles keys and signs transactions should always be read and audited by you before you trust it with real funds. Used incorrectly, it can destroy your money.

Task: you have a transaction hash. Fetch the transaction and its receipt, then decode the input, the logs and, if it failed, the reason. Part of the EVM contract recipes.

The fetch is plain curl to your node ($RPC). In CI, $ETH/<id> is a local mock on 127.0.0.1 that answers with the recorded mainnet response <id> from fixtures/evm-mainnet/ (requests and capture times in PROVENANCE.md); replace it with "$RPC". The live network path is UNTESTED here.

A successful USDC transfer

The transaction, decoded:

curl -s -X POST -H 'Content-Type: application/json' --data '{"jsonrpc":"2.0","id":1,"method":"eth_getTransactionByHash","params":["0xc0ee5b5618437369d0925560368ee87b84569ef1e6a2763983efa5fc437231ab"]}' $ETH/01a | abi-decode --sig 'transfer(address,uint256)'

Its receipt: did it succeed, and what did it emit?

curl -s -X POST -H 'Content-Type: application/json' --data '{"jsonrpc":"2.0","id":1,"method":"eth_getTransactionReceipt","params":["0xc0ee5b5618437369d0925560368ee87b84569ef1e6a2763983efa5fc437231ab"]}' $ETH/01b | jq -c '.result | {status, logs: (.logs | length)}'


curl -s -X POST -H 'Content-Type: application/json' --data '{"jsonrpc":"2.0","id":1,"method":"eth_getTransactionReceipt","params":["0xc0ee5b5618437369d0925560368ee87b84569ef1e6a2763983efa5fc437231ab"]}' $ETH/01b | log-decode --sig 'Transfer(address indexed from, address indexed to, uint256 value)'

A failed Universal Router swap

The receipt says it failed (status 0x0) and has no logs:

curl -s -X POST -H 'Content-Type: application/json' --data '{"jsonrpc":"2.0","id":1,"method":"eth_getTransactionReceipt","params":["0x61495cbde17c4adbbae9760b2bc94b485b782d9c3c8e11d94398815eff36bb14"]}' $ETH/04b | jq -c '.result | {status, logs: (.logs | length)}'

What it tried to do (nested inputs: evm-decode-multicall.md):

curl -s -X POST -H 'Content-Type: application/json' --data '{"jsonrpc":"2.0","id":1,"method":"eth_getTransactionByHash","params":["0x61495cbde17c4adbbae9760b2bc94b485b782d9c3c8e11d94398815eff36bb14"]}' $ETH/04a | jq -r .result.input | abi-decode --sig 'execute(bytes,bytes[],uint256)' | jq -c '{commands: .args[0].value, deadline: .args[2].value}'

A receipt carries no revert data. Replaying the call with eth_call at the parent block is the usual next step, but it runs against end-of-block state, not the state at the tx's position: for this tx the recorded replay (04c) succeeded with 0x, so it did not reproduce the revert:

curl -s -X POST -H 'Content-Type: application/json' --data '{"jsonrpc":"2.0","id":1,"method":"eth_call","params":[{"to":"0x66a9893cc07d91d95644aedd05d03f95e1dba8af","data":"0x…"},"0x190e925"]}' $ETH/04c | jq -c '{result}'

When a replay does revert, decode its error (here 04d, a USDC transferFrom without allowance; more in evm-decode-revert.md):

curl -s -X POST -H 'Content-Type: application/json' --data '{"jsonrpc":"2.0","id":1,"method":"eth_call","params":[{"from":"0x0000000000000000000000000000000000000001","to":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","data":"0x23b872dd000000000000000000000000000000000000000000000000000000000000dead00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000001"},"latest"]}' $ETH/04d | jq .error | abi-decode

NOT BUILT: tracing a mined transaction (debug_traceTransaction); contract-trace traces a call you describe (debug_traceCall), see evm-eth-call.md. The mock returns the recorded response whatever the request body says; the request bodies shown are the ones to send to a real node (the 04c data is elided here; the full request is in PROVENANCE.md).