gpwebpay

A modern Python client for the GPWebPay payment gateway.

gpwebpay handles the RSA signing of outgoing payment requests and the verification of signed callbacks coming back from the gateway, so you can integrate GPWebPay into your Python webshop without dealing with the cryptography directly.

Installation

pip install gpwebpay
# or
uv add gpwebpay

Usage

import base64
import os

from gpwebpay import GpwebpayClient, InvalidSignatureError

client = GpwebpayClient(
    merchant_id=os.environ["GPWEBPAY_MERCHANT_ID"],
    private_key=base64.b64decode(os.environ["GPWEBPAY_MERCHANT_PRIVATE_KEY"]),
    private_key_password=os.environ.get("GPWEBPAY_MERCHANT_PRIVATE_KEY_PASSPHRASE"),
    gateway_public_key=base64.b64decode(os.environ["GPWEBPAY_PUBLIC_KEY"]),
    callback_url="https://shop.example.com/payment_callback",
    # gateway_url defaults to the test environment; pass the production URL when ready
)

# Send a signed payment request to the gateway. Amount is in cents.
response = client.request_payment(order_number="123456", amount=999)
# Redirect the user's browser to the URL the gateway responded with:
# return redirect(str(response.url))

# In your callback handler, verify the response:
try:
    result = client.parse_callback(callback_url)
    # result is a dict of fields, e.g. {"OPERATION": "...", "PRCODE": "0", ...}
except InvalidSignatureError:
    # The callback was tampered with — reject it.
    ...

Configuration

Argument	Required	Default	Description
merchant_id	yes	—	Your merchant ID issued by GPWebPay
private_key	yes	—	PEM-encoded RSA private key bytes
gateway_public_key	yes	—	PEM-encoded x509 certificate from GPWebPay
callback_url	yes	—	Where GPWebPay should redirect users after payment
gateway_url	no	test gateway	Production: https://3dsecure.gpwebpay.com/pgw/order.do
private_key_password	no	None	Passphrase for the private key
currency	no	"978" (EUR)	ISO 4217 numeric currency code
deposit_flag	no	"1"	"1" requests instant payment

Development

This project uses uv for dependency management.

uv sync               # install dependencies
uv run pytest         # run tests
uv run ruff check .   # lint
uv run ruff format .  # format
uv run mypy gpwebpay  # type check

License

MIT