debug_traceCall | Tempo

Tempo API method that traces the execution of a call without creating a transaction on the blockchain. Chainstack Tempo reference.

POST /

debug_traceCall

cURL

curl --request POST \
  --url https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/ \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "method": "debug_traceCall",
  "params": [
    {
      "to": "0x20c0000000000000000000000000000000000000",
      "data": "0x70a082310000000000000000000000009729187d9e8bbefa8295f39f5634ca454dd9d294"
    },
    "latest",
    {}
  ],
  "id": 1
}
'

import requests

url = "https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/"

payload = {
    "jsonrpc": "2.0",
    "method": "debug_traceCall",
    "params": [{
            "to": "0x20c0000000000000000000000000000000000000",
            "data": "0x70a082310000000000000000000000009729187d9e8bbefa8295f39f5634ca454dd9d294"
        }, "latest", {}],
    "id": 1
}
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    jsonrpc: '2.0',
    method: 'debug_traceCall',
    params: [
      {
        to: '0x20c0000000000000000000000000000000000000',
        data: '0x70a082310000000000000000000000009729187d9e8bbefa8295f39f5634ca454dd9d294'
      },
      'latest',
      {}
    ],
    id: 1
  })
};

fetch('https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'jsonrpc' => '2.0',
    'method' => 'debug_traceCall',
    'params' => [
        [
                'to' => '0x20c0000000000000000000000000000000000000',
                'data' => '0x70a082310000000000000000000000009729187d9e8bbefa8295f39f5634ca454dd9d294'
        ],
        'latest',
        [
                
        ]
    ],
    'id' => 1
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/"

	payload := strings.NewReader("{\n  \"jsonrpc\": \"2.0\",\n  \"method\": \"debug_traceCall\",\n  \"params\": [\n    {\n      \"to\": \"0x20c0000000000000000000000000000000000000\",\n      \"data\": \"0x70a082310000000000000000000000009729187d9e8bbefa8295f39f5634ca454dd9d294\"\n    },\n    \"latest\",\n    {}\n  ],\n  \"id\": 1\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/")
  .header("Content-Type", "application/json")
  .body("{\n  \"jsonrpc\": \"2.0\",\n  \"method\": \"debug_traceCall\",\n  \"params\": [\n    {\n      \"to\": \"0x20c0000000000000000000000000000000000000\",\n      \"data\": \"0x70a082310000000000000000000000009729187d9e8bbefa8295f39f5634ca454dd9d294\"\n    },\n    \"latest\",\n    {}\n  ],\n  \"id\": 1\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://tempo-mainnet.core.chainstack.com/c3ce2925b51f1ed18719fe8a23bbdccf/")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"jsonrpc\": \"2.0\",\n  \"method\": \"debug_traceCall\",\n  \"params\": [\n    {\n      \"to\": \"0x20c0000000000000000000000000000000000000\",\n      \"data\": \"0x70a082310000000000000000000000009729187d9e8bbefa8295f39f5634ca454dd9d294\"\n    },\n    \"latest\",\n    {}\n  ],\n  \"id\": 1\n}"

response = http.request(request)
puts response.read_body

200

{
  "jsonrpc": "<string>",
  "id": 123,
  "result": {}
}

Tempo API method that traces the execution of a call without creating a transaction on the blockchain. This is useful for debugging contract interactions before sending actual transactions.

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Parameters

• callObject — the call object:
  • from — (optional) sender address
  • to — recipient address
  • gas — (optional) gas limit
  • gasPrice — (optional) gas price
  • value — (optional) value to send
  • data — (optional) call data
• blockParameter — the block number (hex) or tag (latest, earliest, pending)
• tracerConfig — (optional) tracer configuration object:
  • tracer — tracer type (e.g., callTracer, prestateTracer)

Response

• result — the trace result object, format depends on the tracer used

For the default tracer:

• gas — gas used
• failed — whether the call failed
• returnValue — return data
• structLogs — array of execution steps

debug_traceCall code examples

The following example traces a balanceOf call on the pathUSD token:

ethers.js

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

// pathUSD token address
const PATHUSD = "0x20c0000000000000000000000000000000000000";
const TARGET_ADDRESS = "0x9729187D9E8Bbefa8295F39f5634cA454dd9d294";

// Encode balanceOf(address)
const iface = new ethers.Interface(["function balanceOf(address) view returns (uint256)"]);
const data = iface.encodeFunctionData("balanceOf", [TARGET_ADDRESS]);

const traceCall = async () => {
    // Using default tracer
    const trace = await provider.send("debug_traceCall", [
      {
        to: PATHUSD,
        data: data
      },
      "latest",
      {}
    ]);

    console.log("Gas used:", trace.gas);
    console.log("Failed:", trace.failed);
    console.log("Return value:", trace.returnValue);
    console.log("Execution steps:", trace.structLogs.length);
  };

traceCall();

from web3 import Web3

node_url = "CHAINSTACK_NODE_URL"
web3 = Web3(Web3.HTTPProvider(node_url))

# pathUSD token address
PATHUSD = "0x20c0000000000000000000000000000000000000"
TARGET_ADDRESS = "0x9729187D9E8Bbefa8295F39f5634cA454dd9d294"

# balanceOf(address) calldata
data = "0x70a08231000000000000000000000000" + TARGET_ADDRESS[2:].lower()

result = web3.provider.make_request("debug_traceCall", [
    {
        "to": PATHUSD,
        "data": data
    },
    "latest",
    {}
])

trace = result['result']
print(f"Gas used: {trace['gas']}")
print(f"Failed: {trace['failed']}")
print(f"Return value: {trace['returnValue']}")
print(f"Execution steps: {len(trace['structLogs'])}")

curl -X POST "CHAINSTACK_NODE_URL" \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "debug_traceCall",
    "params": [
      {
        "to": "0x20c0000000000000000000000000000000000000",
        "data": "0x70a082310000000000000000000000009729187d9e8bbefa8295f39f5634ca454dd9d294"
      },
      "latest",
      {}
    ],
    "id": 1
  }'

Body

application/json

jsonrpc · string · default: 2.0

method · string · default: debug_traceCall

params · any[]

Call object, block identifier, and optional tracer config

id · integer · default: 1

Response

200 - application/json

Call trace

jsonrpc · string

id · integer

result · object

Trace result object