This plugin allows a librarian to accept patron payments via Comprise SmartPAY card readers
The SmartPAY password and API key are encrypted at rest using Koha's own encryption, which needs an
encryption_key in koha-conf.xml. Koha does not generate one for you — a fresh instance ships
the placeholder __ENCRYPTION_KEY__, and Koha reports this on the About page.
<encryption_key>a random string of at least 32 bytes</encryption_key>pwgen 32 1 produces a suitable value. Restart Koha after adding it.
If no key is configured the plugin still works, but the credentials stay in cleartext and the configuration page shows a warning. Once a key is set, the stored credentials are encrypted automatically the next time the plugin is upgraded or its configuration page is opened.
Changing encryption_key after the credentials have been encrypted makes them unrecoverable.
Payments will fail with a clear error until they are re-entered on the configuration page.