Context
Part of a long engagement on tintadlaplastykow.pl (custom CMS, 36k+ SKU, since 2022) — this thread: an InPost Pay checkout channel. Goal: a separate purchase path where the store cart connects to the InPost app, and payment plus delivery choice (parcel locker / courier) happen outside the CMS’s classic checkout. The order lands back in the store after the customer finishes in the app.
Period: August 2026
Scope
- Merchant Backend API — IZI endpoints for InPost (basket, binding, confirmation, events, order create/read) with signature verification.
- InPost Pay client — basket sync (products, prices, promotions, consents), browser-to-app binding and order-status events back to InPost.
- Storefront widget — “Pay with InPost” button (product page / cart), basket sync, order-status polling and a dedicated thank-you page.
- Separate checkout — full flow outside the store’s classic cart: APM + courier, pickup point or address, payment in the app.
- CMS persistence — creating the order in the store (line items, InPost Pay payment, shipping), finalizing after payment and syncing statuses to the app.
Result
- InPost Pay checkout is live: customers finish in the app, and the order appears in the store without manual re-entry.
- Widget and Merchant Backend pass InPost verification (delivery methods and thank-you page); statuses flow back to the app.