debug_traceCall | Arbitrum

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Parameters

• object — the transaction call object:
  • from — (optional) the address used to send the transaction.
  • to — the address to which the transaction is directed, a wallet or a smart contract.
  • gas — (optional) the maximum amount of gas that can be used by the transaction.
  • gasPrice — (optional) the amount of gas price the sender is willing to pay for each gas unit in Wei.
  • value — (optional) the value sent with this transaction, encoded as hexadecimal.
  • data — (optional) additional data to be sent with the call, usually used to invoke functions from smart contracts.
• quantity or tag — the block number in hex format or block tag (latest, earliest, pending, safe, finalized).
• object — (optional) an object identifying the type of tracer and its configuration:
  • 4byteTracer — tracer that captures the function signatures and call data sizes.
  • callTracer — tracer that captures information on all call frames executed during a transaction.
  • prestateTracer — tracer with two modes: prestate and diff.

• disableStorage — when enabled, prevents tracing of storage changes.
• disableStack — when enabled, skips tracing of stack changes.
• enableMemory — when false, prevents tracing of memory changes.
• enableReturnData — when false, prevents tracing of return data.
• timeout — timeout period for JavaScript-based tracing calls. Default is 5s.

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Response types

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callTracer response

• object — the callTracer traces object:
  • from — the address of the sender who initiated the transaction.
  • gas — the units of gas included in the transaction by the sender.
  • gasUsed — the total used gas by the call, encoded as hexadecimal.
  • to — the address of the recipient of the transaction. For contract creation transactions, this field is null.
  • input — the optional input data sent with the transaction.
  • output — the return value of the call, encoded as a hexadecimal string.
  • error — an error message in case the execution failed.
  • revertReason — the reason why the transaction was reverted, returned by the smart contract if any.
  • calls — a list of sub-calls made by the contract during the call, each represented as a nested call frame object.

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4byteTracer response

• object — the 4byteTracer traces object:
  • result — a map of the function signature, the call data size, and how many times the function was called.

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prestateTracer response

• object — the prestateTracer traces object:
  • smart contract address — the address of the smart contract associated with the result.
    • balance — the balance of the contract, expressed in Wei and encoded as a hexadecimal string.
    • code — the bytecode of the contract, encoded as a hexadecimal string.
    • nonce — the nonce of the account associated with the contract, represented as an unsigned integer.
    • storage — a map of key-value pairs representing the storage slots of the contract.

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debug_traceCall code examples

const ethers = require('ethers');
const NODE_URL = "YOUR_CHAINSTACK_ENDPOINT";
const provider = new ethers.JsonRpcProvider(NODE_URL);

const traceCall = async () => {
  const call = {
    to: "0xfd086bc7cd5c481dcc9c85ebe478a1c0b69fcbb9",
    data: "0x70a08231000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045"
  };

  const block = "latest";
  const tracer = { tracer: "callTracer" };
  const traces = await provider.send("debug_traceCall", [call, block, tracer]);
  console.log(traces);
};

traceCall();

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Use case