debug_traceCall

debug_traceCall executes a call against a chosen OP Mainnet block state and returns a full opcode-level trace — all without broadcasting a transaction or spending any ETH. It is the simulation counterpart to debug_traceTransaction: you describe a call (the same fields as eth_call), pick a block to run it against, and the node traces the result, optionally applying state and block overrides. On OP Mainnet — the OP Stack rollup with ETH gas, chain ID 10 (0xa) — point the request at https://optimism.therpc.io/YOUR_API_KEY to preview exactly how a contract interaction would behave before you commit to it.

Use cases

Debug an OP Mainnet contract interaction before broadcasting by tracing the exact execution path and any revert reason.
Simulate how a call would behave at a historical block height (past blocks require an archive node).
Profile the gas a prospective transaction would consume without spending any ETH.
Test proposed contract logic against live OP Mainnet state using state overrides, before deploying the change.

Parameters

#	الاسم	النوع	مطلوب	الوصف
1	`transaction`	object	نعم	Call object — same fields as eth_call: `from?`, `to`, `gas?`, `gasPrice?`, `maxFeePerGas?`, `maxPriorityFeePerGas?`, `value?`, `data?`.
2	`blockParameter`	string	لا	Block number or tag defining the state against which the call is simulated.الافتراضي: `latest`
3	`options`	object	لا	Same tracer configuration object as debug_traceTransaction (tracer, tracerConfig, timeout, reexec, enableMemory, enableReturnData, disableStack, disableStorage, limit, debug).
4	`stateOverrides`	object	لا	Optional map of address → { balance, nonce, code, state, stateDiff } overrides applied only for this call.
5	`blockOverrides`	object	لا	Optional map of block-context fields to override (e.g. `number`, `time`, `gasLimit`, `coinbase`, `random`, `baseFee`) for the simulated call.

Response

النوع	الوصف
object	Same shape as debug_traceTransaction: structLog array with default tracer, or tracer-specific object (callTracer, prestateTracer, etc.).

Example request

1curl https://optimism.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "debug_traceCall",
7    "params": [
8        {
9          "to": "0x0000000000000000000000000000000000000000",
10          "data": "0x"
11        },
12        "latest",
13        {},
14        {},
15        {}
16      ],
17    "id": 1
18  }'

Try it live in the Optimism playground.

Errors & troubleshooting

الكود	الرسالة	السبب
`-32601`	`Method not found`	debug namespace not enabled on the node.
`-32602`	`Invalid params`	Transaction object is missing required fields or blockParameter is unrecognized.
`-32000`	`execution reverted`	Simulated call reverted; trace is still returned up to the revert point.

Common pitfalls

The trace runs against the specified block's state, so results can differ from real execution if the call depends on block context such as coinbase, timestamp, or base fee — override these explicitly when it matters.
Simulating against a historical OP Mainnet block requires an archive node; a pruned node only has recent state.
Responses can be huge for complex contracts; use a compact tracer like callTracer or disable stack/memory/storage in the options to keep output small.

Supported networks

Mainnet — Chain ID: 10
Sepolia — Chain ID: 11155420

#	الاسم	النوع	مطلوب	الوصف
1	`transaction`	object	نعم	Call object — same fields as eth_call: `from?`, `to`, `gas?`, `gasPrice?`, `maxFeePerGas?`, `maxPriorityFeePerGas?`, `value?`, `data?`.
2	`blockParameter`	string	لا	Block number or tag defining the state against which the call is simulated.الافتراضي: `latest`
3	`options`	object	لا	Same tracer configuration object as debug_traceTransaction (tracer, tracerConfig, timeout, reexec, enableMemory, enableReturnData, disableStack, disableStorage, limit, debug).
4	`stateOverrides`	object	لا	Optional map of address → { balance, nonce, code, state, stateDiff } overrides applied only for this call.
5	`blockOverrides`	object	لا	Optional map of block-context fields to override (e.g. `number`, `time`, `gasLimit`, `coinbase`, `random`, `baseFee`) for the simulated call.

النوع

الوصف

object

Same shape as debug_traceTransaction: structLog array with default tracer, or tracer-specific object (callTracer, prestateTracer, etc.).

Example request

1curl https://optimism.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "debug_traceCall",
7    "params": [
8        {
9          "to": "0x0000000000000000000000000000000000000000",
10          "data": "0x"
11        },
12        "latest",
13        {},
14        {},
15        {}
16      ],
17    "id": 1
18  }'

الكود

الرسالة

السبب

-32601

Method not found

debug namespace not enabled on the node.

-32602

Invalid params

Transaction object is missing required fields or blockParameter is unrecognized.

-32000

execution reverted

Simulated call reverted; trace is still returned up to the revert point.

Common pitfalls

The trace runs against the specified block's state, so results can differ from real execution if the call depends on block context such as coinbase, timestamp, or base fee — override these explicitly when it matters.

Simulating against a historical OP Mainnet block requires an archive node; a pruned node only has recent state.

Responses can be huge for complex contracts; use a compact tracer like callTracer or disable stack/memory/storage in the options to keep output small.

debug_traceCall

Use cases

Parameters

Response

Example request

Errors & troubleshooting

Common pitfalls

Supported networks

See also

هل أنت مستعد لاستدعاء هذا في الإنتاج؟

debug_traceCall

Use cases

Parameters

Response

Example request

Errors & troubleshooting

Common pitfalls

Supported networks

See also