rex — Reth Node Explorer

Use execution replay-tx to inspect the call tree produced by a transaction. The command calls debug_traceTransaction with the callTracer, flattens the nested calls, and prints gas, value, calldata size, and any call errors.

Command

rex execution replay-tx \
  --tx 0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Example Output

EXECUTION REPLAY TX

Tx:           0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
Calls:        3
Failed calls: 0
Max depth:    1

DEPTH TYPE         FROM                                       TO                                           VALUE        GAS   GAS USED IN BYTES OUT BYTES ERROR
    0 CALL         0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266 0x5fbdb2315678afecb367f032d93f642f64180aa3 0 wei     150000      48672       68         32 -
    1 STATICCALL   0x5fbdb2315678afecb367f032d93f642f64180aa3 0x0000000000000000000000000000000000000001 -          42112       3120        0         32 -

How It Works

debug_traceTransaction replays the transaction from the node’s stored chain state. The transaction must be available to the node, and the RPC endpoint must expose the debug namespace. Start a local Reth node with debug RPC enabled:

reth node \
  --dev \
  --http \
  --http.api eth,net,web3,debug \
  --datadir ./alice

Field Notes

Calls counts the flattened root call and all nested calls.
Failed calls counts call frames with an error field.
IN BYTES is calldata size for the call frame.
OUT BYTES is returndata size for the call frame.
VALUE is shown in wei or gwei using the same formatting as other Rex reports.