A published Odoo 18 payment provider for Pays.cz — secure redirect flow, signature verification, and no manual setup step to get wrong.

Odoo ships payment providers for the processors that dominate Western Europe and North America. In the Czech Republic, those are not the processors anyone uses — which left Czech merchants on Odoo 18 without a working option.

This is a full payment provider integrated into Odoo 18's e-commerce checkout, implementing Pays.cz's secure redirect flow. The return leg carries HMAC-MD5 signature verification, so a tampered callback cannot mark an unpaid order as paid — the failure mode that makes a payment integration worse than no integration.

It handles CZK, EUR and USD and localises into Czech, Slovak, English, Russian and Japanese. A post-init hook configures the payment method on install, removing the manual provider setup that is the most common way these integrations end up half-configured in production.

Published on the Odoo App Store, which means it passed a first-party marketplace review rather than being self-declared as finished.