Call Tracer

Capture the nested CALL/CREATE tree with gas usage, return data, and log events.

The call tracer records the nested tree of CALL, STATICCALL, DELEGATECALL, CALLCODE, and CREATE operations. It shows which contracts called which, with gas usage and return data at each level.

Usage

mega-evme run 0x... --trace --tracer call

Options

Flag	Default	Description
--trace.call.only-top-call	false	Only trace the top-level call — omit nested internal calls
--trace.call.with-log	false	Include LOG events in the call trace output

Output Format

The call tracer emits a Geth-compatible nested JSON structure.

Schema

Each call node contains:

Field	Type	Description
type	string	Call type: CALL, STATICCALL, DELEGATECALL, CALLCODE, CREATE, CREATE2
from	address	Caller address
to	address	Callee address
gas	hex number	Gas provided to the call
gasUsed	hex number	Gas consumed by the call
input	hex bytes	Calldata
output	hex bytes	Return data (present on success)
value	hex number	ETH value transferred (if any)
error	string	Revert reason (present on failure)
calls	array	Nested child call nodes (recursive)
logs	array	LOG events (only with --trace.call.with-log)

Each log entry (when --trace.call.with-log is set):

Field	Type	Description
address	address	Contract that emitted the log
topics	array	Log topics as hex strings
data	hex bytes	Log data
position	hex number	Position in the transaction

Example Output

Running WETH.name() against MegaETH mainnet with --tracer call shows the nested call tree — WETH delegates to L1Block to resolve the chain name:

{
  "from": "0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266",
  "gas": "0x97a960",
  "gasUsed": "0x1130f",
  "to": "0x4200000000000000000000000000000000000006",
  "input": "0x06fdde03",
  "output": "0x00000000000000000000000000000000000000000000000000...5772617070656420457468657200...",
  "calls": [
    {
      "from": "0x4200000000000000000000000000000000000006",
      "gas": "0x949600",
      "gasUsed": "0x15c4",
      "to": "0x4200000000000000000000000000000000000015",
      "input": "0xd8444715",
      "output": "0x00000000000000000000000000000000000000000000000000...4574686572...",
      "calls": [
        {
          "from": "0x4200000000000000000000000000000000000015",
          "gas": "0x918a50",
          "gasUsed": "0x247",
          "to": "0xc0d3c0d3c0d3c0d3c0d3c0d3c0d3c0d3c0d30015",
          "input": "0xd8444715",
          "output": "0x00000000000000000000000000000000000000000000000000...4574686572...",
          "value": "0x0",
          "type": "DELEGATECALL"
        }
      ],
      "type": "STATICCALL"
    }
  ],
  "value": "0x0",
  "type": "CALL"
}

With --trace.call.with-log, WETH.deposit() shows the emitted Deposit event:

{
  "from": "0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266",
  "gas": "0x97a960",
  "gasUsed": "0x171a8",
  "to": "0x4200000000000000000000000000000000000006",
  "input": "0xd0e30db0",
  "logs": [
    {
      "address": "0x4200000000000000000000000000000000000006",
      "topics": [
        "0xe1fffcc4923d04b559f4d29a8bfc6cda04eb5b0d3c460751c2402c5c5cc9109c",
        "0x000000000000000000000000f39fd6e51aad88f6f4ce6ab8827279cfffb92266"
      ],
      "data": "0x00000000000000000000000000000000000000000000000000038d7ea4c68000",
      "position": "0x0"
    }
  ],
  "value": "0x38d7ea4c68000",
  "type": "CALL"
}

Examples

Full call tree:

# Trace a WETH.balanceOf call against live mainnet state
mega-evme tx \
  --fork --fork.rpc https://mainnet.megaeth.com/rpc \
  --sender.balance 1ether \
  --receiver 0x4200000000000000000000000000000000000006 \
  --input 0x70a08231000000000000000000000000f39fd6e51aad88f6f4ce6ab8827279cfffb92266 \
  --trace --tracer call

Top-level call only (useful for simple gas analysis):

mega-evme tx \
  --receiver 0x4200000000000000000000000000000000000006 \
  --input 0x06fdde03 \
  --trace --tracer call \
  --trace.call.only-top-call

Include log events:

# WETH.deposit() emits a Transfer event — use --with-log to capture it
mega-evme tx \
  --fork --fork.rpc https://mainnet.megaeth.com/rpc \
  --sender.balance 1ether \
  --receiver 0x4200000000000000000000000000000000000006 \
  --input 0xd0e30db0 \
  --value 1000000000000000 \
  --trace --tracer call \
  --trace.call.with-log