debug_traceCall

Traces a contract call without creating a transaction on Optimism Layer 2.

Parameters

1. Call Object

   • from - Sender address (optional)
   • to - Contract address
   • gas - Gas limit (optional)
   • gasPrice - Gas price (optional)
   • value - Value (optional)
   • data - Call data

2. Block Parameter - QUANTITY|TAG

3. Trace Configuration - OBJECT (optional)

Implementation Examples

cURL

curl -X POST https://api-optimism-mainnet-archive.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "debug_traceCall",
    "params": [
      {
        "to": "0x4200000000000000000000000000000000000006",
        "data": "0x70a08231000000000000000000000000742d35cc6634c0532925a3b844bc9e7595f0beb"
      },
      "latest",
      {"tracer": "callTracer"}
    ],
    "id": 1
  }'

JavaScript

// Trace WETH balanceOf call on Optimism
const response = await fetch('https://api-optimism-mainnet-archive.n.dwellir.com/YOUR_API_KEY', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    jsonrpc: '2.0',
    method: 'debug_traceCall',
    params: [
      {
        to: "0x4200000000000000000000000000000000000006", // WETH on Optimism
        data: "0x70a08231000000000000000000000000742d35cc6634c0532925a3b844bc9e7595f0beb"
      },
      "latest",
      {tracer: "callTracer"}
    ],
    id: 1
  })
});

const data = await response.json();
console.log('Call trace:', data.result);

Response Example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "type": "CALL",
    "from": "0x0000000000000000000000000000000000000000",
    "to": "0x4200000000000000000000000000000000000006",
    "gasUsed": "0x2329",
    "output": "0x0000000000000000000000000000000000000000000000000de0b6b3a7640000"
  }
}

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Need help? Contact our support team or check the Optimism documentation.