Invoke a smart contract

Returns a result from EVM execution such as cost-free execution of read-only smart contract queries, gas estimation, and transient simulation of read-write operations. If the estimate field is set to true gas estimation is executed. This API can process calls against the latest block or specific historical blocks when a hexadecimal or decimal block number is provided in the block field.

POST /api/v1/contracts/call

Invoke a smart contract

cURL

curl --request POST \
  --url https://api.example.com/api/v1/contracts/call \
  --header 'Content-Type: application/json' \
  --data '
{
  "to": "0xd9d0c5c0ff85758bdf05a7636f8036d4d065f5b6",
  "block": "latest",
  "data": "0x47f1aae7",
  "estimate": true,
  "from": "00000000000000000000000000000000000004e2",
  "gas": 15000000,
  "gasPrice": 100000000,
  "value": 0
}
'

import requests

url = "https://api.example.com/api/v1/contracts/call"

payload = {
    "to": "0xd9d0c5c0ff85758bdf05a7636f8036d4d065f5b6",
    "block": "latest",
    "data": "0x47f1aae7",
    "estimate": True,
    "from": "00000000000000000000000000000000000004e2",
    "gas": 15000000,
    "gasPrice": 100000000,
    "value": 0
}
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({
    to: '0xd9d0c5c0ff85758bdf05a7636f8036d4d065f5b6',
    block: 'latest',
    data: '0x47f1aae7',
    estimate: true,
    from: '00000000000000000000000000000000000004e2',
    gas: 15000000,
    gasPrice: 100000000,
    value: 0
  })
};

fetch('https://api.example.com/api/v1/contracts/call', 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://api.example.com/api/v1/contracts/call",
  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([
    'to' => '0xd9d0c5c0ff85758bdf05a7636f8036d4d065f5b6',
    'block' => 'latest',
    'data' => '0x47f1aae7',
    'estimate' => true,
    'from' => '00000000000000000000000000000000000004e2',
    'gas' => 15000000,
    'gasPrice' => 100000000,
    'value' => 0
  ]),
  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://api.example.com/api/v1/contracts/call"

	payload := strings.NewReader("{\n  \"to\": \"0xd9d0c5c0ff85758bdf05a7636f8036d4d065f5b6\",\n  \"block\": \"latest\",\n  \"data\": \"0x47f1aae7\",\n  \"estimate\": true,\n  \"from\": \"00000000000000000000000000000000000004e2\",\n  \"gas\": 15000000,\n  \"gasPrice\": 100000000,\n  \"value\": 0\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://api.example.com/api/v1/contracts/call")
  .header("Content-Type", "application/json")
  .body("{\n  \"to\": \"0xd9d0c5c0ff85758bdf05a7636f8036d4d065f5b6\",\n  \"block\": \"latest\",\n  \"data\": \"0x47f1aae7\",\n  \"estimate\": true,\n  \"from\": \"00000000000000000000000000000000000004e2\",\n  \"gas\": 15000000,\n  \"gasPrice\": 100000000,\n  \"value\": 0\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.example.com/api/v1/contracts/call")

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  \"to\": \"0xd9d0c5c0ff85758bdf05a7636f8036d4d065f5b6\",\n  \"block\": \"latest\",\n  \"data\": \"0x47f1aae7\",\n  \"estimate\": true,\n  \"from\": \"00000000000000000000000000000000000004e2\",\n  \"gas\": 15000000,\n  \"gasPrice\": 100000000,\n  \"value\": 0\n}"

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

200

{
  "result": "0x0000000000006d8d"
}

{
  "_status": {
    "messages": [
      {
        "data": "0x3000",
        "detail": "Generic detailed error message",
        "message": "Generic error message"
      }
    ]
  }
}

{
  "_status": {
    "messages": [
      {
        "data": "0x3000",
        "detail": "Generic detailed error message",
        "message": "Generic error message"
      }
    ]
  }
}

{
  "_status": {
    "messages": [
      {
        "data": "0x3000",
        "detail": "Generic detailed error message",
        "message": "Generic error message"
      }
    ]
  }
}

{
  "_status": {
    "messages": [
      {
        "data": "0x3000",
        "detail": "Generic detailed error message",
        "message": "Generic error message"
      }
    ]
  }
}

{
  "_status": {
    "messages": [
      {
        "data": "0x3000",
        "detail": "Generic detailed error message",
        "message": "Generic error message"
      }
    ]
  }
}

{
  "_status": {
    "messages": [
      {
        "data": "0x3000",
        "detail": "Generic detailed error message",
        "message": "Generic error message"
      }
    ]
  }
}

Body

application/json

to · file · required

The 20-byte hexadecimal EVM address the transaction is directed to.

Required string length: 40 - 42

Pattern: ^(0x)?[A-Fa-f0-9]{40}$

block · string | null

Hexadecimal block number or the string "latest", "pending", "earliest". Defaults to "latest".

Pattern: ^((0x)?[0-9a-fA-F]+|(earliest|pending|latest))$

Example:

"latest"

data · file | null

Hexadecimal method signature and encoded parameters. Up to 131072 bytes as at most 262146 hexadecimal digits including optional leading 0x.

Maximum string length: 262146

Pattern: ^(0x)?[0-9a-fA-F]+$

estimate · boolean | null

Whether gas estimation is called. Defaults to false.

Example:

true

from · file | null

The 20-byte hexadecimal EVM address the transaction is sent from.

Required string length: 40 - 42

Pattern: ^(0x)?[A-Fa-f0-9]{40}$

gas · integer<int64> | null

Gas provided for the transaction execution. Defaults to 15000000.

Required range: x >= 0

Example:

15000000

gasPrice · integer<int64> | null

Gas price used for each paid gas.

Required range: x >= 0

Example:

100000000

value · integer<int64> | null

Value sent with this transaction. Defaults to 0.

Required range: x >= 0

Example:

0

Response

200

application/json

OK

result · file

Result in hexadecimal from executed contract call.

Pattern: ^0x[0-9a-fA-F]+$