debug_traceCall - BSC

Example code for the debug_traceCall JSON RPC method. Сomplete guide on how to use debug_traceCall JSON RPC in GetBlock Web3 documentation.

The debug_traceCall method lets you run eth_call with tracing on the BNB Smart Chain. This is useful for simulating and debugging contract calls without sending a transaction.

Parameters

Parameter	Type	Required	Description
transaction	object	Yes	Transaction call object
blockNumber	string	Yes	Block number or "latest"
options	object	No	Tracer options

Request Example

cURL

cURL

curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "debug_traceCall",
    "params": [{
        "to": "0x55d398326f99059fF775485246999027B3197955",
        "data": "0x70a08231000000000000000000000000742d35cc6634c0532925a3b844bc9e7595f8bb45"
    }, "latest", {"tracer": "callTracer"}],
    "id": "getblock.io"
}'

JavaScript (Axios)

request.js

const axios = require('axios');

const url = 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/';

const payload = {
    jsonrpc: '2.0',
    method: 'debug_traceCall',
    params: [{
        to: '0x55d398326f99059fF775485246999027B3197955',
        data: '0x70a08231000000000000000000000000742d35cc6634c0532925a3b844bc9e7595f8bb45'
    }, 'latest', { tracer: 'callTracer' }],
    id: 'getblock.io'
};

axios.post(url, payload, {
    headers: { 'Content-Type': 'application/json' }
})
.then(response => console.log(JSON.stringify(response.data, null, 2)))
.catch(error => console.error(error));

Python

request.py

import requests

url = "https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/"

payload = {
    "jsonrpc": "2.0",
    "method": "debug_traceCall",
    "params": [{
        "to": "0x55d398326f99059fF775485246999027B3197955",
        "data": "0x70a08231000000000000000000000000742d35cc6634c0532925a3b844bc9e7595f8bb45"
    }, "latest", {"tracer": "callTracer"}],
    "id": "getblock.io"
}

response = requests.post(url, headers={"Content-Type": "application/json"}, json=payload)
print(response.json())

Rust

main.rs

use reqwest::Client;
use serde_json::json;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();
    
    let payload = json!({
        "jsonrpc": "2.0",
        "method": "debug_traceCall",
        "params": [{
            "to": "0x55d398326f99059fF775485246999027B3197955",
            "data": "0x70a08231..."
        }, "latest", {"tracer": "callTracer"}],
        "id": "getblock.io"
    });

    let response = client
        .post("https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&payload)
        .send()
        .await?;

    let result: serde_json::Value = response.json().await?;
    println!("{:#?}", result);
    
    Ok(())
}

Response Example

response.json

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": {
        "from": "0x0000000000000000000000000000000000000000",
        "gas": "0x17d7840",
        "gasUsed": "0x5d9b",
        "to": "0x55d398326f99059ff775485246999027b3197955",
        "input": "0x70a08231000000000000000000000000742d35cc6634c0532925a3b844bc9e7595f8bb45",
        "output": "0x0000000000000000000000000000000000000000000000000000000000000000",
        "value": "0x0",
        "type": "CALL"
    }
}

Response Parameters

Parameter	Type	Description
type	string	Call type
gasUsed	string	Gas consumed
output	string	Return data

Use Cases

• Simulate contract calls

• Debug before sending transactions

• Analyze call traces

• Test contract interactions

Error Handling

Error Code	Description
-32602	Invalid params
-32603	Internal error

SDK Integration

Ethers.js

ethers.js

const { ethers } = require('ethers');

const provider = new ethers.JsonRpcProvider('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/');

const trace = await provider.send('debug_traceCall', [{
    to: '0x55d398326f99059fF775485246999027B3197955',
    data: '0x70a08231...'
}, 'latest', { tracer: 'callTracer' }]);
console.log(trace);

Viem

viem.js

import { createPublicClient, http } from 'viem';
import { bsc } from 'viem/chains';

const client = createPublicClient({
    chain: bsc,
    transport: http('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/')
});

const trace = await client.request({
    method: 'debug_traceCall',
    params: [{ to: '0x55d398...', data: '0x70a08231...' }, 'latest', { tracer: 'callTracer' }]
});