Create payment via form

Integration through the 1Payment payment form is the simplest way to start accepting bank card payments.

The card payment process consists of four steps:

1. Initialization — your server sends a request with order parameters to the 1Payment endpoint.
2. Receive link — the system returns a unique URL for the payment page.
3. Payment — you redirect the user to the received address; there they enter card details and confirm the payment.
4. Notification (callback) — after the transaction completes, we send a payment status notification to your notify_url.

These fields are required to create the payment form correctly.

Allow you to configure form behavior and pass customer data.

Signature: MD5, lowercase (hex). General rules — API request format.

Formula:

MD5(init_form + <параметры_без_sign_в_алфавитном_порядке_через_&> + <API_KEY>)

Example string before hashing:

init_formamount=50&description=test_payment&partner_id=1234&project_id=5678secret_key

const crypto = require('crypto');
const axios = require('axios');

async function createCardForm(apiKey, params) {
  // 1. Сортируем параметры по алфавиту
  const sortedKeys = Object.keys(params).sort();
  const queryString = sortedKeys.map((key) => `${key}=${params[key]}`).join('&');

  // 2. Генерируем подпись с префиксом init_form
  const baseString = `init_form${queryString}${apiKey}`;
  params.sign = crypto.createHash('md5').update(baseString).digest('hex');

  // 3. Отправляем POST-запрос
  try {
    const response = await axios.post('https://api.1payment.com/init_form', params);
    return response.data; // в ответе поле url — ссылка на форму
  } catch (error) {
    console.error('Ошибка:', error.message);
  }
}

// Пример данных запроса
const mockApiKey = process.env.ONEPAYMENT_API_KEY;
const mockData = {
  partner_id: 1234,
  project_id: 5678,
  amount: '50.00',
  user_data: 'order_777',
  shop_url: 'https://test.com',
  description: 'test_payment',
};

createCardForm(mockApiKey, mockData).then(console.log);

Successful response (200):

{
  "url": "https://merchant.1payment.com/xZ5g7F"
}

The url field is the payment page address to which you must redirect the payer.

Request error (400):

{
  "error_code": 2
}

You can use the following data to test card payments:

After the transaction status changes, our server sends a POST request in JSON format to your notify_url.

Important: your server must return HTTP 200 OK. Otherwise, the system retries the callback once per minute for 10 minutes.

Callback signature verification: MD5 of all parameters in alphabetical order joined with & + API_KEY (without the init_form prefix). For details, see API request format.

• Create subscription payment
• Create host2host (GATE) payment
• Payment statuses
• Payment refunds
• Transaction statuses
• Error codes (API)
• Error codes (declines)