Estimate fee

Calculates the fees required to send a message. Provide the destination address and message body. For new contract deployments, also include init_code and init_data. Set ignore_chksig to true when estimating before signing. Returns a breakdown of storage, gas, and forwarding fees.

POST /api/v2/estimateFee

Estimate fee

cURL

curl --request POST \
  --url https://toncenter.com/api/v2/estimateFee \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "address": "<string>",
  "body": "<string>",
  "init_code": "<string>",
  "init_data": "<string>",
  "ignore_chksig": true
}
'

import requests

url = "https://toncenter.com/api/v2/estimateFee"

payload = {
    "address": "<string>",
    "body": "<string>",
    "init_code": "<string>",
    "init_data": "<string>",
    "ignore_chksig": True
}
headers = {
    "X-API-Key": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'X-API-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    address: '<string>',
    body: JSON.stringify('<string>'),
    init_code: '<string>',
    init_data: '<string>',
    ignore_chksig: true
  })
};

fetch('https://toncenter.com/api/v2/estimateFee', 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://toncenter.com/api/v2/estimateFee",
  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([
    'address' => '<string>',
    'body' => '<string>',
    'init_code' => '<string>',
    'init_data' => '<string>',
    'ignore_chksig' => true
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-API-Key: <api-key>"
  ],
]);

$response = curl_exec($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://toncenter.com/api/v2/estimateFee"

	payload := strings.NewReader("{\n  \"address\": \"<string>\",\n  \"body\": \"<string>\",\n  \"init_code\": \"<string>\",\n  \"init_data\": \"<string>\",\n  \"ignore_chksig\": true\n}")

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

	req.Header.Add("X-API-Key", "<api-key>")
	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://toncenter.com/api/v2/estimateFee")
  .header("X-API-Key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"address\": \"<string>\",\n  \"body\": \"<string>\",\n  \"init_code\": \"<string>\",\n  \"init_data\": \"<string>\",\n  \"ignore_chksig\": true\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://toncenter.com/api/v2/estimateFee")

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

request = Net::HTTP::Post.new(url)
request["X-API-Key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"address\": \"<string>\",\n  \"body\": \"<string>\",\n  \"init_code\": \"<string>\",\n  \"init_data\": \"<string>\",\n  \"ignore_chksig\": true\n}"

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

200

{
  "ok": true,
  "result": {
    "@type": "query.fees",
    "source_fees": {
      "@type": "fees",
      "in_fwd_fee": 123,
      "storage_fee": 123,
      "gas_fee": 123,
      "fwd_fee": 123
    },
    "destination_fees": [
      {
        "@type": "fees",
        "in_fwd_fee": 123,
        "storage_fee": 123,
        "gas_fee": 123,
        "fwd_fee": 123
      }
    ]
  },
  "@extra": "<string>"
}

{
  "ok": false,
  "code": 401,
  "error": "API key does not exist"
}

{
  "ok": false,
  "code": 403,
  "error": "Network not allowed"
}

{
  "ok": false,
  "code": 422,
  "error": "Stack should be array"
}

{
  "ok": false,
  "code": 429,
  "error": "Ratelimit exceeded"
}

{
  "ok": false,
  "code": 500,
  "error": "Exit code <N> != 0"
}

{
  "ok": false,
  "code": 504,
  "error": "LITE_SERVER_NETWORK timeout"
}

Authorizations

APIKeyHeaderAPIKeyQuery

X-API-Key · string · header · required

API key header of the form X-API-Key: <token>, where <token> is the API key. Requests without a key are limited to 1 RPS. Refer to the authentication guide for details.

Body

application/json

Request to estimate transaction fees. Include the target address, message body, and optionally init code/data for contract deployment.

address · string · required

Account address in raw format (e.g., 0:ca6e321c...) or user-friendly format (e.g., EQDKbjIcfM...). All formats are automatically detected.

body · string · required

Message body in BoC format, base64 encoded.

init_code · string

Contract code for deployment messages, BoC format, base64 encoded. Omit for regular transfers.

init_data · string

Initial contract storage for deployment, BoC format, base64 encoded. Omit for regular transfers.

ignore_chksig · boolean · default: true

Set to true to skip signature verification during fee estimation; otherwise false. Useful when a real signature is not yet available.

Response

200

application/json

Returns the estimated fees (gas, storage, forwarding) for the specified message.

ok · boolean · default: true · required

Returns true if the request succeeded; otherwise false. See the error field for details.

result · object · required

Response data. Present only when ok is true.

Show child attributes

@extra · string

Optional request ID that can be passed in the request and received back in the response. Useful for matching async responses.