debug_traceCall

debug_traceCall runs a call against a chosen block's state on the Avalanche C-Chain and returns a full opcode-level trace, all without ever submitting a transaction or spending any AVAX. The C-Chain is Avalanche's EVM chain, where gas is denominated in AVAX and Snowman consensus finalizes blocks in roughly one to two seconds. Because nothing is broadcast, you can probe how a call would behave — its execution path, revert reason, and gas profile — entirely off-chain. Send the request to https://avalanche.therpc.io/YOUR_API_KEY (chain ID 43114, hex 0xa86a), optionally with state and block overrides, and the response mirrors debug_traceTransaction for the tracer you pick.

Use cases

Debug a C-Chain contract interaction before broadcasting by tracing the exact execution path and capturing the revert reason.
Simulate how a call would have behaved at a historical Avalanche block height (past blocks require an archive node).
Profile the gas cost of a prospective transaction on a DeFi protocol like Aave or Trader Joe without spending any AVAX.
Test proposed contract-logic changes against live C-Chain state using stateOverrides to inject modified bytecode.

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://avalanche.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 Avalanche 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 call runs against the named block's state, so results can diverge from real execution when the logic depends on block context such as block.timestamp or the C-Chain coinbase — use blockOverrides to control these.
Historical block states require an archive node; a pruned Avalanche node only retains recent state.
The response can be very large for complex contracts; use a compact tracer like callTracer, or disable stack, memory, and storage capture in the options.

Supported networks

Mainnet — Chain ID: 43114
Fuji

#	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://avalanche.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 call runs against the named block's state, so results can diverge from real execution when the logic depends on block context such as block.timestamp or the C-Chain coinbase — use blockOverrides to control these.

Historical block states require an archive node; a pruned Avalanche node only retains recent state.

The response can be very large for complex contracts; use a compact tracer like callTracer, or disable stack, memory, and storage capture in the options.

debug_traceCall

Use cases

Parameters

Response

Example request

Errors & troubleshooting

Common pitfalls

Supported networks

See also

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debug_traceCall

Use cases

Parameters

Response

Example request

Errors & troubleshooting

Common pitfalls

Supported networks

See also