debug_traceCall

Tracer is required

On rpc.linea.build, the default tracer is not supported. You must specify a tracer in the options object. Supported tracers are callTracer and prestateTracer. flatCallTracer is not supported.

Simulates a call at a given block and returns the trace, without submitting a transaction. Useful for debugging contract interactions before sending them.

Parameters

• transaction: [required] Transaction call object (same fields as eth_call).
• blockParameter: [required] Hexadecimal block number, or latest, earliest, pending, finalized.
• options: [required] Object specifying the tracer:
  • tracer: [required] "callTracer" or "prestateTracer".

Returns

Same trace output as debug_traceTransaction, but for a simulated call.

Example: callTracer

This example simulates balanceOf(address) on the USDC contract.

Request

curl https://rpc.linea.build \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "debug_traceCall",
    "params": [
      {
        "to": "0x176211869ca2b568f2a7d4ee941e073a821ee1ff",
        "data": "0x70a08231000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045"
      },
      "latest",
      {"tracer": "callTracer"}
    ],
    "id": 1
  }'

Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "from": "0x0000000000000000000000000000000000000000",
    "to": "0x176211869ca2b568f2a7d4ee941e073a821ee1ff",
    "gas": "0x2faf080",
    "gasUsed": "0x79b6",
    "input": "0x70a08231000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045",
    "output": "0x000000000000000000000000000000000000000000000000000000000026009c",
    "calls": [
      {
        "from": "0x176211869ca2b568f2a7d4ee941e073a821ee1ff",
        "to": "0xab838fe7d492c621a5b1b23952af99cc37a2e0d3",
        "gas": "0x2ee96d1",
        "gasUsed": "0x9e1",
        "input": "0x70a08231000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045",
        "output": "0x000000000000000000000000000000000000000000000000000000000026009c",
        "value": "0x0",
        "type": "DELEGATECALL"
      }
    ],
    "value": "0x0",
    "type": "CALL"
  }
}

prestateTracer is also supported and returns the pre-execution state of every account the call would touch, identical in shape to the debug_traceTransaction prestateTracer response.