JURAKUEN

The checkout session is built per request: the Japanese catalogue prices in yen, the English one in dollars, with line items constructed dynamically rather than held as fixed price objects. One product, two markets, no duplicated catalogue.

Payment events are verified against the signing secret before anything is acted on, and both the immediate completion and the delayed success — convenience-store and bank transfer payments that settle days later — are handled. The receipt is sent from the webhook, so it arrives whether or not the customer ever returned to the success page.

Browser language detection is switched off and the locale is always in the path. A link shared by a Japanese customer opens in Japanese for the person they sent it to, instead of being redirected by that person's browser settings.

The sitemap carries both locales, and the transactional pages — cart, payment result — are kept out of it and out of the index, so search results point at products and articles rather than at a stranger's empty cart.