trace_call

Simulates a call and returns call traces, state differences, or both.

Erigon reference · All supported methods

Parameters

Parameters are positional, in the order below.

Parameter	Type	Required	Description
transaction	Transaction object	Yes	Call fields such as from, to, data, value, and gas.
traceTypes	Array of strings	Yes	trace, stateDiff, or both.
block	Block number or tag	No	State to execute against; defaults to latest.

Transaction fields

Field	Meaning
from	Sender address used during execution
to	Destination address; omit for contract creation where supported
data or input	Encoded call data or contract creation code; use one field
value	Value transferred in wei, as a hexadecimal quantity
gas	Gas allowance for the simulation, as a hexadecimal quantity
gasPrice	Legacy gas price in wei; use instead of EIP-1559 fee fields
maxFeePerGas, maxPriorityFeePerGas	EIP-1559 fee limits in wei, where applicable
accessList	Addresses and storage keys supplied for execution

Return value

Tracing output in the requested formats. Replay and simulation results include execution output and the requested call traces or state differences; multi-call and whole-block methods return one result per call or transaction.

Example

Replace <gateway-url> with your gateway base URL and <service-url> with the chain’s service path, such as service/ethereum.

curl -X POST "<gateway-url>/<service-url>" \
  -H "Content-Type: application/json" \
  --data '{"jsonrpc":"2.0","id":1,"method":"trace_call","params":[{"to":"0x2222222222222222222222222222222222222222","data":"0x"},["trace"],"latest"]}'

Illustrative response; values depend on the selected network and request:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "output": "0x",
    "stateDiff": null,
    "trace": [],
    "vmTrace": null
  }
}

Direct behavior

The gateway selects providers supporting the requested tracing group and format. Unsupported formats are rejected rather than replaced.

Supported output types are trace, stateDiff, or both. vmTrace is not supported. The gateway matches the requested combination automatically.

Historical simulations require archive state. Requests whose execution point is determined by latest follow the reference-block rules.

Limits

Simulations allow up to 30 million gas per call. Omitted gas uses that ceiling; an explicit higher allowance is rejected rather than silently reduced. State and block overrides are not included in the supported contract.

Reconstruction, internal splitting, and recovery share the gateway deadline; none gives the request an unlimited fresh budget.

For providers

Qualify for the entire applicable tracing group, including required formats and options. Historical combinations are verified separately; recent success alone does not establish historical coverage.

See provider qualification for checks and continued eligibility.