How it works

1. The customer chooses The Pay. pretix creates a ThePay payment and redirects the customer.

2. The state is always read from ThePay over the authenticated API, never taken from the request. Three things trigger that read:

   • the customer returning,

   • ThePay’s notifications,

   • a periodic task.

   The periodic task covers notifications ThePay gave up on, since it retries them for only 2 days.

3. A bank transfer can arrive a working day or more later. The payment stays pending and is confirmed by the notification. ThePay accepts the payment until the order’s payment term plus a configurable number of days. After that, ThePay returns a late transfer to the payer automatically.

4. Refunds, including customers cancelling their own orders, are sent to ThePay. pretix shows a refund as done only once ThePay reports it as returned. A refund ThePay declines becomes failed and is logged. Refunds made in the ThePay administration appear in pretix as external refunds.

Requirements

• pretix 2025.1 or later, Python 3.11 or later

• A ThePay project (merchant ID, project ID, API password)

Installation

pip install pretix-thepay

In production we bake it into the pretix image, see https://github.com/KrisIsNew/hellpretix. Enable the plugin per event, then configure it under Settings → Payment → The Pay.

Configuration

Operational requirements:

• IP whitelist: add the public IP of the pretix server in ThePay administration → Implementation.

• Clock: ThePay rejects requests whose SignatureDate is more than 20 s off, so run NTP.

• Periodic task: pretix’s runperiodic must run (the standalone image does this). The plugin re-checks open payments and refunds at most every 10 minutes.

• Refund balance: ThePay pays refunds from your ThePay balance. Without enough balance it waits 10 days and then declines the refund.

Cancellations and automatic refunds

Event → Settings → Cancellation:

• Allow customers to cancel paid orders.

• Choose to refund automatically to the original payment method.

pretix refunds automatically only when ThePay can. Otherwise it creates a manual refund for you. ThePay cannot refund automatically:

• card payments older than 6 months,

• bank transfers whose payer account ThePay does not know (e.g. cash deposits),

• methods without the returnable tag.

Development

pip install -e ".[test]"
pytest
flake8 pretix_thepay tests && isort --check-only pretix_thepay tests

The tests run against a real pretix (pretix.testutils.settings, SQLite) with the ThePay API mocked by responses. Releasing: see RELEASING.md.

References

• ThePay API: https://docs.thepay.eu/

• pretix payment provider API: https://docs.pretix.eu/dev/development/api/payment.html

License

Apache License 2.0