debug_traceCall

debug_traceCall runs a call against a chosen block's state and hands back a full opcode-level trace, all without submitting a transaction or burning a single unit of gas. BNB Smart Chain (BSC) charges that gas in BNB and hosts the BEP-20 contracts behind protocols like PancakeSwap and Venus, so a dry run that costs nothing is genuinely useful here. Aim it at chain ID 56 via https://bsc.therpc.io/YOUR_API_KEY. The call object and block parameter are only the start: state and block overrides let you rehearse a contract interaction under hypothetical balances or an invented block context. Any block but the latest forces a reach back into historical state, which is heavy, so plan on a debug-enabled archive node.

Use cases

Debug a contract interaction before you broadcast it. The trace shows its exact path and the precise opcode where it would revert.
Replay how a call would have behaved at a past height, which leans on archive state for the block you target.
Profile the gas a prospective transaction would burn without spending a single BNB wei.
Test proposed contract logic against live state by injecting bytecode through state overrides.

Parameters

#	Name	Type	Required	Description
1	`transaction`	object	Yes	Call object — same fields as eth_call: `from?`, `to`, `gas?`, `gasPrice?`, `maxFeePerGas?`, `maxPriorityFeePerGas?`, `value?`, `data?`.
2	`blockParameter`	string	No	Block number or tag defining the state against which the call is simulated.Default: `latest`
3	`options`	object	No	Same tracer configuration object as debug_traceTransaction (tracer, tracerConfig, timeout, reexec, enableMemory, enableReturnData, disableStack, disableStorage, limit, debug).
4	`stateOverrides`	object	No	Optional map of address → { balance, nonce, code, state, stateDiff } overrides applied only for this call.
5	`blockOverrides`	object	No	Optional map of block-context fields to override (e.g. `number`, `time`, `gasLimit`, `coinbase`, `random`, `baseFee`) for the simulated call.

Response

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

Example request

1curl https://bsc.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 BNB Smart Chain playground.

Errors & troubleshooting

Code	Message	Cause
`-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 call runs against the block state you name, so results drift from real execution whenever the logic leans on block context such as coinbase or timestamp.
Reaching a historical block state requires an archive node. A pruned node holds only recent state.
Output balloons for an intricate contract. Pick a compact tracer like callTracer, or just switch off the stack and storage dumps. Heavy traces may get throttled on lower tiers.

Supported networks

Mainnet — Chain ID: 56
Testnet — Chain ID: 97