trace_call

Traces a call without creating a transaction on Base, returning the trace output.

Archive Node Required

This method requires an archive node. It is not available on full nodes.

Use Cases

• Call simulation - Preview internal calls before sending a transaction
• Contract interaction analysis - Understand how contracts interact
• Gas estimation - Analyze gas usage patterns for consumer dApps, SocialFi, NFT marketplaces, and merchant payment integrations

Parameters

Parameter	Type	Required	Description
callObject	Object	Yes	Transaction call object (from, to, gas, value, data)
traceTypes	Array	Yes	Trace types: ["trace"], ["vmTrace"], ["stateDiff"], or combinations
blockNumber	QUANTITY|TAG	No	Block number or tag (default: latest)

Request

{
  "jsonrpc": "2.0",
  "method": "trace_call",
  "params": [
    {
      "to": "0x4200000000000000000000000000000000000006",
      "data": "0x70a082310000000000000000000000004200000000000000000000000000000000000006"
    },
    ["trace"],
    "latest"
  ],
  "id": 1
}

Code Examples

cURL

curl -X POST https://api-base-mainnet-archive.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "trace_call",
    "params": [
      {"to": "0x4200000000000000000000000000000000000006", "data": "0x70a082310000000000000000000000004200000000000000000000000000000000000006"},
      ["trace"],
      "latest"
    ],
    "id": 1
  }'

JavaScript

import { JsonRpcProvider } from 'ethers';

const provider = new JsonRpcProvider('https://api-base-mainnet-archive.n.dwellir.com/YOUR_API_KEY');

const result = await provider.send('trace_call', [
  {
    to: '0x4200000000000000000000000000000000000006',
    data: '0x70a082310000000000000000000000004200000000000000000000000000000000000006'
  },
  ['trace'],
  'latest'
]);
console.log('Trace output:', result.trace);
console.log('VM trace:', result.vmTrace);

Python

from web3 import Web3

w3 = Web3(Web3.HTTPProvider('https://api-base-mainnet-archive.n.dwellir.com/YOUR_API_KEY'))

result = w3.provider.make_request('trace_call', [
    {
        'to': '0x4200000000000000000000000000000000000006',
        'data': '0x70a082310000000000000000000000004200000000000000000000000000000000000006'
    },
    ['trace'],
    'latest'
])
print(f'Trace: {result["result"]["trace"]}')

Related Methods

• trace_filter - Filter traces by criteria
• eth_call - Execute call without trace
• trace_transaction - Trace a specific transaction