CHECKOUT · DELIVERY SCHEDULING
Delivery Slots for Magento 2 & Mage-OS with live capacity control, safe booking reservations, Hyvä Checkout support, REST & GraphQL APIs, postcode rules, delivery pricing and rescheduling built for real-world delivery operations.
Product details
Magento 2 & Mage-OS Delivery Slots Extension
A Magento 2 delivery date extension should do far more than put a calendar on the checkout. qoliber Delivery Slots runs delivery capacity like inventory — reserving slots before checkout, re-validating availability under a database lock when the order is placed, and automatically returning capacity when an order is canceled or fully refunded.
The result is a delivery scheduling system designed for stores where the date and time shown to the customer must remain operationally true — even when multiple customers race for the same slot, a checkout fails halfway through, or an existing delivery is rescheduled.
Tuesday, 11 August
The “2 left” is the line to look at: it counts confirmed orders plus every live 30-minute hold except your own. Capacity is then re-checked under a lock when the order is placed, so the slot count cannot silently drop below zero. The green pill represents the customer's active hold, prolonged while they continue shopping.
Almost every Magento delivery date extension can display a calendar and save a delivery date on the order. The architectural differences appear when real-world events collide: two checkouts racing for the final slot, an order placement crashing midway, or a canceled order continuing to consume delivery capacity.
Without it: the last slot sells twice.
The booking is recorded under a per-method-and-date database lock, with capacity re-validated inside it. An over-capacity slot aborts order placement instead of silently overbooking — and the lock fails closed.
Without it: ghost bookings eat real capacity.
A failure observer releases the booking unless the order actually committed, and an hourly reconciliation removes booking rows that no order accounts for — batched and split-database safe.
Without it: an abandoned browser holds a slot all day.
Holds slide — 30 minutes, prolonged on activity — but carry an absolute lifetime cap of 4× the window. Expired holds are purged by cron, while a customer's own hold never blocks their own checkout.
Without it: canceled orders still consume slots.
Canceling an order or fully refunding it frees the delivery slot immediately. Capacity goes straight back on sale, while partial refunds correctly leave the delivery booking in place.
Without it: “today” drifts in non-UTC stores.
Availability, delivery cut-offs, change policies and reminders all resolve in the store's own timezone and scope. No availability flicker around midnight and no delivery reminder sent on the wrong day.
Without it: a reschedule overbooks the target slot.
Customer and admin reschedules run in one transaction under the same lock, judged on net effect for same-day moves and gated by your cut-off policy. The delivery reminder automatically re-arms for the new date.
The pattern is the same everywhere: the calendar is the easy part. The real engineering is building a Magento delivery scheduling system whose slot count is still correct after concurrency, checkout failures, cancelations and rescheduling.
There are solid Magento delivery date and delivery scheduler extensions available. A checkout calendar, cut-off times, holiday lists and order-grid columns are now table stakes. The meaningful difference is what happens after the customer selects a date: capacity control, concurrent bookings, cancellation recovery, rescheduling and operational reliability.
| What can go wrong | qoliber | Competing modules |
|---|---|---|
| Two checkouts race for the last slot | Lock at placement per method + date, capacity re-checked inside, fail-closed |
Not published |
| Booking before checkout | 30-minute sliding hold header widget; live holds count against capacity |
Checkout-only |
| Capacity limits | Per slot, per date, per day peak-date overrides, e.g. Christmas Eve = 2 |
Premium tier only |
| Canceled or refunded order | Slot freed automatically cancel + full-refund observers, hourly reconciliation |
Not published |
| Public holidays | Computed, 11 countries fixed + Easter-derived, this year and next |
Manual date lists |
| Delivery pricing | Distance, fees, surcharges per-km (Google), base fee, minimum charge, free-above, slot premiums |
Flat surcharges at best |
| Customer moves the delivery | Self-service, capacity-safe same lock, one transaction, cut-off policy, reminder re-armed |
Sometimes; checks not published |
| Full-page cache | Safe by design no session data in markup, hydrates client-side |
Not published |
| Hyvä storefront + checkout | Native companions, included Alpine.js widget + Magewire picker |
Often a paid add-on |
| After the order | Reminder + .ics invite token-protected calendar link, manifest export, REST + GraphQL |
Reminders at best |
The “Competing modules” column reflects what nine competing Magento delivery extensions publish on their public feature pages, reviewed August 2026. “Not published” means it isn't advertised — not that it is absent. The qoliber column describes what the shipped code does, and every row is verifiable in the repository.
Built for agencies and technical teams delivering Magento and Mage-OS projects, qoliber Delivery Slots combines native storefront integrations with API access, cache-safe frontend behaviour and operational tooling for real delivery workflows.
Magento Open Source 2.4.x and Mage-OS.
8.1 – 8.5, PHPStan level 8, zero findings.
Luma, and Hyvä with Hyvä Checkout — Alpine.js and Magewire companions, verified end-to-end on Hyvä 1.5.
Typed REST availability endpoint, slot data on the order REST API, and GraphQL support.
No. The booking is recorded under a per-method-and-date database lock with capacity re-validated inside it, so the second order aborts with a clear message instead of overbooking. If the lock itself cannot be acquired, the system fails closed — a “try again in a moment”, never a double-booked van.
The hold slides — 30 minutes by default, prolonged while they keep shopping — but has an absolute lifetime cap of four times the window. Expired holds are purged by cron every 15 minutes, so nobody can park on a slot indefinitely, while a customer's own hold never blocks their own checkout.
Yes, natively and at no extra charge: an Alpine.js header widget for the Hyvä theme and a Magewire delivery slot picker for Hyvä Checkout, including the required-slot step gate. Both are companions to the same booking engine, so Luma and Hyvä storefronts cannot drift apart.
If you allow it. Reschedule and cancel are available from My Account while the order hasn't shipped, gated by a merchant-defined cut-off such as “no changes closer than N hours to the slot”. Every move re-checks capacity under the same lock, and the reminder re-arms for the new date. Admins get the same controls on the order view.
Yes. Availability is exposed through a typed REST endpoint described in the generated Swagger schema, the booked slot travels as checkout extension attributes validated server-side, and delivery information is exposed on the order REST API and GraphQL for ERPs, PWAs and custom storefronts.
No. The widget markup contains no session data, so pages remain fully cacheable. Reservation state hydrates client-side from a customer-data section, allowing full-page cache and the delivery booking widget to coexist by design.
Yes. The extension includes postcode zones alongside weight, size, cart-value and product-level eligibility controls, allowing delivery methods and slot availability to reflect the operational limits of your delivery service.
Distance-based pricing is optional. Without a Google key, methods price flat. With a key, a failed lookup fails closed for methods enforcing a maximum distance — the method hides rather than guessing — and degrades to flat pricing where no distance limit is configured.
WHAT IT FIXES
Almost any delivery date extension can show a calendar. qoliber Delivery Slots runs delivery capacity like inventory: it holds a slot before checkout, re-validates availability under a database lock when the order is placed and returns capacity when an order is canceled or fully refunded.
INSTALL · COMPOSER
Your license adds the package to your private qoliber repository. Add the repository once, then require the package like any other dependency — no ZIP files, no copying folders into app/code.
# Once per project: add your private qoliber repository # (the exact command is in your account → Composer & keys) composer require qoliber/delivery-slots php bin/magento setup:upgrade ✓ Installed. Updates arrive with composer update.