trace_call

POST

https://eth-archive.nownodes.io/

Authorizations

ApiKeyAuthApiKeyAuth

api-key string

NOWNodes API key passed in the api-key header.

Execute a new message call immediately without creating a transaction on the blockchain. This method allows debugging of contract calls by simulating execution and returning detailed trace information. It's particularly useful for testing and debugging smart contract interactions without spending gas.

Body

application/json

Request payload for trace_call.

jsonrpcstring2.0required

JSON-RPC version identifier

methodstringtrace_callrequired

The JSON-RPC method name

paramsArray<object | Array<string> | string>required

Parameters for the trace_call method

Show child attributes

Single JSON-RPC parameter value accepted by this method.

One of

fromstring

The address the transaction is sent from (20 bytes, hex encoded with 0x prefix). Optional for contract creation transactions.

tostring

The address the transaction is directed to (20 bytes, hex encoded with 0x prefix). Required for message calls, omitted for contract creation.

gasstring

The gas limit for the transaction (hex encoded). Maximum amount of gas units the call can consume.

gasPricestring

The gas price in wei (hex encoded). Amount of wei per gas unit.

valuestring

The value transferred in wei (hex encoded). Amount of ether to send with the call.

datastring

The compiled code of a contract OR hash of the invoked method signature and encoded parameters. Hex encoded data (function selector + ABI encoded arguments).

Array<string>tracevmTracestateDiff

The block number or block identifier. Can be "latest", "earliest", "pending", or a specific block number (hex encoded).

string

idintegerrequired

Request identifier used to match the response with the request.

Response

200OK

Successfully executed trace call and returned detailed trace information

400Bad Request

Bad request - invalid parameters

401Unauthorized

Unauthorized: API key is present but rejected by the NOWNodes gateway.

405Method Not Allowed

Method Not Allowed. Returned by the NOWNodes gateway for malformed or unsupported gateway-level requests.

422Unprocessable Entity

Missing API key. The NOWNodes gateway returns plain text for this error.

500Internal Server Error

Internal server error

trace_call

curl -X POST 'https://eth-archive.nownodes.io/' \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "method": "trace_call",
    "params": [
      {
        "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
        "to": "0x06af07097c9eeb7fd685c692751d5c66db49c215",
        "gas": "0x76c0",
        "gasPrice": "0x9184e72a000",
        "value": "0xde0b6b3a7640000",
        "data": "0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e0000000000000000000000000000000000000000000000000000000000000001"
      }
    ],
    "id": 1
  }'

import { JsonRpcProvider } from "ethers";

const provider = new JsonRpcProvider("https://eth-archive.nownodes.io/");
const result = await provider.send("trace_call", [
  {
    "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
    "to": "0x06af07097c9eeb7fd685c692751d5c66db49c215",
    "gas": "0x76c0",
    "gasPrice": "0x9184e72a000",
    "value": "0xde0b6b3a7640000",
    "data": "0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e0000000000000000000000000000000000000000000000000000000000000001"
  }
]);
console.log(result);

require 'eth'
require 'json'
require 'net/http'

uri = URI('https://eth-archive.nownodes.io/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
  "jsonrpc": "2.0",
  "method": "trace_call",
  "params": [
    {
      "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
      "to": "0x06af07097c9eeb7fd685c692751d5c66db49c215",
      "gas": "0x76c0",
      "gasPrice": "0x9184e72a000",
      "value": "0xde0b6b3a7640000",
      "data": "0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e0000000000000000000000000000000000000000000000000000000000000001"
    }
  ],
  "id": 1
}'

response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) do |http|
  http.request(request)
end

puts JSON.parse(response.body)

from web3 import Web3

w3 = Web3(Web3.HTTPProvider("https://eth-archive.nownodes.io/"))
response = w3.provider.make_request("trace_call", [
  {
    "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
    "to": "0x06af07097c9eeb7fd685c692751d5c66db49c215",
    "gas": "0x76c0",
    "gasPrice": "0x9184e72a000",
    "value": "0xde0b6b3a7640000",
    "data": "0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e0000000000000000000000000000000000000000000000000000000000000001"
  }
])
print(response)

import { createPublicClient, http } from "viem";

const client = createPublicClient({
  transport: http("https://eth-archive.nownodes.io/"),
});

const result = await client.request({
  method: "trace_call",
  params: [
  {
    "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
    "to": "0x06af07097c9eeb7fd685c692751d5c66db49c215",
    "gas": "0x76c0",
    "gasPrice": "0x9184e72a000",
    "value": "0xde0b6b3a7640000",
    "data": "0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e0000000000000000000000000000000000000000000000000000000000000001"
  }
],
});

console.log(result);

const endpoint = "https://eth-archive.nownodes.io/";
const apiKey = "YOUR_API_KEY";

async function nownodesRequest(payload) {
  const response = await fetch(endpoint, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "api-key": apiKey,
    },
    body: JSON.stringify(payload),
  });

  return response.json();
}

const result = await nownodesRequest({ jsonrpc: "2.0", method: "trace_call", params: [
  {
    "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
    "to": "0x06af07097c9eeb7fd685c692751d5c66db49c215",
    "gas": "0x76c0",
    "gasPrice": "0x9184e72a000",
    "value": "0xde0b6b3a7640000",
    "data": "0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e0000000000000000000000000000000000000000000000000000000000000001"
  }
], id: 1 });
console.log(result);

const response = await fetch('https://eth-archive.nownodes.io/', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
      "jsonrpc": "2.0",
      "method": "trace_call",
      "params": [
        {
          "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
          "to": "0x06af07097c9eeb7fd685c692751d5c66db49c215",
          "gas": "0x76c0",
          "gasPrice": "0x9184e72a000",
          "value": "0xde0b6b3a7640000",
          "data": "0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e0000000000000000000000000000000000000000000000000000000000000001"
        }
      ],
      "id": 1
    }),
});

const data = await response.json();

import requests

payload = {
  "jsonrpc": "2.0",
  "method": "trace_call",
  "params": [
    {
      "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
      "to": "0x06af07097c9eeb7fd685c692751d5c66db49c215",
      "gas": "0x76c0",
      "gasPrice": "0x9184e72a000",
      "value": "0xde0b6b3a7640000",
      "data": "0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e0000000000000000000000000000000000000000000000000000000000000001"
    }
  ],
  "id": 1
}

response = requests.post('https://eth-archive.nownodes.io/', json=payload)
data = response.json()

require 'net/http'
require 'json'

uri = URI('https://eth-archive.nownodes.io/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
    "jsonrpc": "2.0",
    "method": "trace_call",
    "params": [
      {
        "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
        "to": "0x06af07097c9eeb7fd685c692751d5c66db49c215",
        "gas": "0x76c0",
        "gasPrice": "0x9184e72a000",
        "value": "0xde0b6b3a7640000",
        "data": "0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e0000000000000000000000000000000000000000000000000000000000000001"
      }
    ],
    "id": 1
  }'

response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |http| http.request(request) }
data = JSON.parse(response.body)

Request Body

{
  "jsonrpc": "2.0",
  "method": "trace_call",
  "params": [
    {
      "from": "0x742d35cc6634c0532925a3b844bc454e4438f44e",
      "to": "0x06af07097c9eeb7fd685c692751d5c66db49c215",
      "gas": "0x76c0",
      "gasPrice": "0x9184e72a000",
      "value": "0xde0b6b3a7640000",
      "data": "0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e0000000000000000000000000000000000000000000000000000000000000001"
    }
  ],
  "id": 1
}

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "output": "0x",
    "stateDiff": null,
    "trace": [
      {
        "type": "call",
        "action": {
          "from": "0x0b6f2116323c12ee731de6818e41861561bcd44c",
          "callType": "call",
          "gas": "0xffffffffffffadf7",
          "input": "0x",
          "to": "0xe28cac160c2a79dfa1fbd2169ac5fa5d061cf186",
          "value": "0x0"
        },
        "error": "Reverted",
        "result": {
          "gasUsed": "0x1bfa",
          "output": "0x"
        },
        "subtraces": 1,
        "traceAddress": []
      },
      {
        "type": "call",
        "action": {
          "from": "0xe28cac160c2a79dfa1fbd2169ac5fa5d061cf186",
          "callType": "delegatecall",
          "gas": "0xfbffffffffff941c",
          "input": "0x",
          "to": "0x6cb28384f21b18924fa312aa2e10d4e813e66263",
          "value": "0x0"
        },
        "error": "Reverted",
        "result": {
          "gasUsed": "0x44",
          "output": "0x"
        },
        "subtraces": 0,
        "traceAddress": [
          0
        ]
      }
    ],
    "vmTrace": null
  }
}

{
  "jsonrpc": "2.0",
  "id": 1,
  "error": {
    "code": -32602,
    "message": "Invalid params",
    "data": "invalid type: string \"not-a-valid-param\", expected struct TransactionRequest at line 1 column 19"
  }
}

{
  "jsonrpc": "2.0",
  "id": 1,
  "error": {
    "code": -32602,
    "message": "Invalid params"
  }
}

Unknown API_key

Method Not Allowed

Missing API_key

{
  "jsonrpc": "2.0",
  "id": 1,
  "error": {
    "code": -32000,
    "message": "execution reverted"
  }
}

Documentation

How to migrate to NOWNodes

trace_call

Authorizations

Body

Response