PayWay REST API - Python

• Store customers, their card and bank account in PayWay
• Take payment using a stored credit card or bank account
• Process and Capture a pre-authorisation
• Lookup or poll transactions
• Refund transactions
• Void transactions
• Update a customer's payment setup in PayWay

Install

Requires Python 3.11 or later.

pip install python-payway

Take payment using a stored credit card

Create a Client class with your PayWay API credentials

from payway.client import Client

client = Client(merchant_id='<your_payway_merchant_id>',
                bank_account_id='<your_payway_bank_account_id>',
                publishable_api_key='<your_payway_publishable_api_key>',
                secret_api_key='<your_payway_secret_api_key>')

Create a PayWayCustomer class with your customer's details

customer = PayWayCustomer(custom_id='c981a',
                          customer_name='John Smith',
                          email_address='johnsmith@example.com',
                          send_email_receipts=False,  # not available in sandbox
                          phone_number='0343232323',
                          street='1 Test Street',
                          street2='2 Test Street',
                          city_name='Sydney',
                          state='NSW',
                          postal_code='2000')

Create a PayWayCard class with your customer's card details

card = PayWayCard(card_number='',
                  cvn='',
                  card_holder_name='',
                  expiry_date_month='',
                  expiry_date_year='')

Create a token from your card and create a customer in PayWay

token_response, errors = client.create_card_token(card)
token = token_response.token        
customer.token = token
payway_customer, customer_errors = client.create_customer(customer)

Note the 'payway_customer' object contains the full customer response fields from PayWay.

Create a Payment class with the payment details and process the transaction

customer_number = payway_customer.customer_number
payment = PayWayPayment(customer_number=customer_number,
                        transaction_type='payment',
                        amount='',
                        currency='aud',
                        order_number='',
                        ip_address='')
transaction, errors = client.process_payment(payment)

Check the transaction for the result

if not errors and transaction.status == 'approved':
    # process successful response

Take payment using a credit card token only

client = Client(merchant_id='',
                bank_account_id='',
                publishable_api_key='',
                secret_api_key='')
card = PayWayCard(card_number='',
                  cvn='',
                  card_holder_name='',
                  expiry_date_month='',
                  expiry_date_year='')
token_response, errors = client.create_card_token(card)
# your customer reference number or a stored PayWay customer number
customer_number = ''    
payment = PayWayPayment(customer_number=customer_number,
                        transaction_type='payment',
                        amount='',
                        currency='aud',
                        order_number='',
                        ip_address='',
                        token=token_response.token,
                        merchant_id=client.merchant_id)
transaction, errors = client.process_payment(payment)

Retries

Retries are off by default. Opt in with max_retries (and optionally retry_delay, the base wait in seconds between attempts):

client = Client(merchant_id='<your_payway_merchant_id>',
                bank_account_id='<your_payway_bank_account_id>',
                publishable_api_key='<your_payway_publishable_api_key>',
                secret_api_key='<your_payway_secret_api_key>',
                max_retries=2,
                retry_delay=1.0)

This follows PayWay's retry guidance (https://www.payway.com.au/docs/rest.html#network-errors):

• Requests are resent on connection errors, timeouts and HTTP 429/503 responses, waiting retry_delay seconds between attempts (linear backoff, or the response's Retry-After header when present). PayWay suggests a 20 second wait; keep retry_delay small for synchronous checkout flows.
• POSTs are only retried when an idempotency_key was supplied — the same Idempotency-Key is resent so PayWay replays the original response instead of processing a duplicate payment. POSTs without a key (and PUTs) are never retried. GETs are always safe to retry.
• Other errors (including HTTP 500/502/504) are never retried, per PayWay's advice.

transaction, errors = client.process_payment(payment, idempotency_key=str(uuid.uuid4()))

Handling errors

Documented errors (such as 422 Unprocessable entity) are parsed into an PaymentError class that you can use in an customer error message. For more info, visit https://www.payway.com.au/docs/rest.html#http-response-codes

if errors:
    for error in errors: 
        print(error.field_name)
        print(error.message) 
        print(error.field_name)
    # or use a method
    PaymentError().list_to_message(errors) 

Direct Debit

Direct debit transactions are possible by creating a token from a bank account:

bank_account = BankAccount(account_name='Test', bsb='000-000', account_number=123456)
token_response, errors = client.create_bank_account_token(bank_account)
token = token_response.token

Store the token with a customer in PayWay using the same process as the card outlined above.

Note: direct debit transactions take days to process so they must be polled regularly for the latest transaction status from the customer's bank.

Lookup transaction

Poll a transaction using the get_transaction method.

transaction, errors = client.get_transaction(transaction.transaction_id)

Process and capture a pre-authorisation

To process a credit card pre-authorisation using a credit card stored against a customer use preAuth as the transaction_type along with the customer's PayWay number, amount and currency.

pre_auth_payment = PayWayPayment(customer_number='',
                                 transaction_type='preAuth',
                                 amount='',
                                 currency='aud',
                                 order_number='',
                                 ip_address='')
transaction, errors = client.process_payment(pre_auth_payment)

To capture the pre-authorisation supply a pre-authorisation transaction ID, capture as the transaction_type along with an amount to capture.

capture_payment = PayWayPayment(transaction_type='capture',
                                parent_transaction_id='',
                                amount='',
                                order_number='',
                                ip_address='')
transaction, errors = client.process_payment(capture_payment)

Refunds

Refund a transaction by supplying a PayWay transaction ID and the refund amount.

refund, errors = client.refund_transaction(
    transaction_id=transaction.transaction_id,
    amount=transaction.principal_amount,
)

Voiding a transaction

Void a transaction by supplying a PayWay transaction ID.

void_transaction, errors = client.void_transaction(transaction.transaction_id)

Update Payment Setup

Update a customer's payment setup with a new credit card or bank account in PayWay. Supply the new token and an existing PayWay customer number.

payment_setup, errors = client.update_payment_setup(new_token, payway_customer.customer_number)

Additional notes

PayWay API documentation https://www.payway.com.au/docs/rest.html

It is recommended to use PayWay's Trusted Frame https://www.payway.com.au/docs/rest.html#trusted-frame when creating a single use token of a card or bank account so your PCI-compliance scope is reduced.

Fraud

Please follow PayWay's advice about reducing your risk of fraudulent transactions. https://www.payway.com.au/docs/card-testing.html#card-testing

Running the project

uv sync

uv provisions a suitable Python (3.11+) and installs the dev dependencies automatically.

Testing

uv run pytest tests/ -v