SDK for Python

SDK for Python is a software development kit for development of web services which are capable of integrating with the Benker payment solutions to perform purchase by using Payment Page. This section describes how to use SDK for Python to build purchase experience from inside of your web service.

SDK for Python is compatible with Python version 3.5 or higher.

What can I do with SDK for Python?

SDK for Python allows you to do the following:

Calculate signature and generate an URL for opening the Payment Page.
Check callback signature and extract payment details from callbacks.

What's inside?

SDK for Python contains the libraries for development and automated testing, as well as the service files.

Using SDK for Python

To start using SDK for Python you need to complete the following tasks:

Make sure you have you have ready your merchant ID and secret key obtained from Benker:
1. If your company has never obtained any ID or secret key from Benker, you need to submit an application for connecting to the Benker payment platform.
2. If your company already has an ID and a secret key to sign messages obtained from Benker, you need to notify the Benker technical support that you want to use SDK for Python and consult the customer support on how to arrange a test run.
Integrate the Benker payment solution in your web service:
1. Install the SDK for Python libraries.
2. Import the libraries you need into your web service application.
Test and put your web service in production mode.

With any questions regarding the use of SDK for Python, contact Benker the technical support specialists at help@benker.io.

Installing and importing libraries

You can install the SDK for Python libraries manually or automatically with pip, a package-management system used to install and manage software packages written in Python.

The following steps describe how to install the SDK for Python libraries by using pip:

If you have not yet installed pip, you need to download, install and check settings. For more information, see https://pip.pypa.io/en/stable/.
Navigate into the web service directory in command line interface and run the following command:
```
pip install benker-sdk
```
Pip automatically downloads the SDK for Python libraries in the Scripts directory to enable you to use all the classes provided by the libraries.

Import the classes into your web service project:

from payment_page_sdk.gate import Gate
from payment_page_sdk.payment import Payment

Opening payment form

A URL for opening Payment Page consists of a set of parameters, which are signed to secure the data transmitted to the Benker payment platform. SDK for Python allows you to seamlessly sign parameters and generate URLs. To open the Payment Page payment form by using SDK for Python do the following:

Create an instance of the Payment class and specify payment details.

payment = Payment('186', 'TEST_1555943554067')
    // Project ID and payment ID and payment ID must be unique within your project scope
payment.payment_amount = 1001
    // Amount in minor currency units
payment.payment_currency = 'EUR'
    //  Currency in ISO-4217 alpha-3 format
payment.customer_id = 'customer_112'  
    // Customer ID
payment.payment_description = 'Test payment'
    // Payment description (optional)

All parameters in this example, except for the payment description, are mandatory for any purchase.

You can also use any other optional parameters available for Payment Page. For more information about the Payment Page invocation parameters, see Parameters for opening the payment form.

Create a gate instance and initiate it with the secret key you obtained from Benker. The secret key is required to sign parameters.
```
gate = Gate('<secret_key>')
    // Secret key you obtained from technical support service
```

Generate the URL for opening the payment form:

payment_url = gate.get_purchase_payment_page_url(payment)

The URL must contain payment parameters and signature (abbreviated):

https://paymentpage.benker.io/payment?signature=OEKRlLXQsa2..
               ..gWg%3D%3D&payment_id=pid_1555943554067...

Use the generated URL for opening the payment form (details).

Here is an example of generating a URL for opening a payment form in English. The payment method selection page includes detailed payment information including amount, currency, and short payment description.

Figure 1. Example of generating the URL for opening Payment Page

payment = Payment('186', 'TEST_1555943554067')
    // Project ID and payment ID and payment ID must be unique within your project scope
payment.payment_amount = 1001
payment.payment_currency = 'EUR'  
    // Amount in minor currency units and currency in ISO-4217 alpha-3 format
payment.customer_id = 'customer_112'  
    // Customer ID
payment.payment_description = 'Test payment'
    // Payment description
payment.language_code = 'en'
    // Language code to use in payment form
gate = Gate('<secret_key>')    
    // Secret key
payment_url = gate.get_purchase_payment_page_url(payment)
    // Complete request with signature

Using the test mode

When working with the SDK for Python, you can use the test mode. It allows you to check completeness and correctness of specified parameters and get information about errors if there were any.

Before using the test mode, make sure that the server of the web service can send the HTTP requests to sdk.benker.io. This allows you to specify various parameters to open the payment form as part of the testing activities (you will be able to use both test and production parameters) and to analyse error information. Use the following code:

payment = Payment(<project_id>, "<payment_id_in_your_service>")
payment.payment_amount = 1001
payment.payment_currency = 'EUR'
payment.payment_description = 'Test payment'
 
gate = Gate("<secret_key>")
 
try:  # Attempting to execute the code
    return gate.get_purchase_payment_page_url(payment)  
    # Receiving the URL to opent the payment form
except ValidationException as e:  # Validating possible exceptions
    print(e)  # Displaying error messages in the console
 
return null

Information about the errors that occurred in testing is provided in error messages as follows:

One or more parameters is not valid:
 
Customer_id:
    Must be not null // The id of the customer, required for this request, was not specified
Account_token:
    Invalid account token  // Incorrect token value was specified

If there are no errors, then the generated URL for opening Payment Page is correct.

Processing callbacks

The Benker payment platform sends payment results to the callback URL you specified when connecting to Benker. Callback is an HTTP POST request that contains response data in JSON format. To extract payment information from the JSON string do the following:

Create an instance of Gate with the secret key, if you did not it earlier.
```
gate = Gate('<secret_key>')
```
Create an instance of Callback by using the JSON string from the callback obtained from the Benker payment platform:
```
callback = gate.handle_callback(data)
```

Use the following methods for extracting callback information. You can get either full payment information or request specific payment parameters:

callback.get_payment_id()            // Getting payment ID
callback.get_payment_status()        // Getting payment status
callback.get_payment()               // Getting payment body

By using SDK for Python, you can automatically check validity of callback signature. Below, you will find an example of callback that includes signature and payment results.

Figure 2. Sample payment callback

POST /notify/success HTTP/1.1
Content-Length: 1237
User-Agent: GuzzleHttp/6.3.3 curl/7.47.0 PHP/7.0.32-0ubuntu0.16.04.1
Content-Type: application/json
Host: webservice.com

{
  "project_id": 200,
  "payment": {
    "id": "abc12345",
    "type": "purchase",
    "status": "success",
    "date": "2025-03-20T14:22:06+0000",
    "method": "Greek Banks",
    "sum": {
      "amount": 1000,
      "currency": "EUR"
    },
    "description": "Success"
  },
  "customer": {
    "id": "123"
  },
  "operation": {
    "id": 9529253065607,
    "type": "sale",
    "status": "success",
    "date": "2025-03-20T14:22:06+0000",
    "created_date": "2025-03-20T14:22:00+0000",
    "request_id": "f1de353331a01fd14163fe4226-00009530",
    "sum_initial": {
      "amount": 1000,
      "currency": "EUR"
    },
    "sum_converted": {
      "amount": 1000,
      "currency": "EUR"
    },
    "code": "0",
    "message": "Success",
    "provider": {
      "id": 1914,
      "payment_id": "",
      "auth_code": ""
    }
  },
  "signature": "OBjT3RaJnOWsDXOclvWoC6+CFSCtLprTo8VFbN6BYVQD2tVK/3d9k+RRA/7N9TV6OQqk+0uPUnx4/c8uaUurw=="
}