Live Shipping Rates · API2Cart
Live Shipping Rates at Checkout
Plug your own real-time rate calculation into a merchant’s checkout — carrier APIs, custom logic, anything — without platform-specific shipping integrations.
Static shipping tables do not work for every business — freight carriers, regional rate cards, and weight-based pricing all need a live calculation at the moment of checkout.
API2Cart lets you register a callback service: when a shopper reaches checkout, the store requests a rate, your callback calculates it, and the result is returned in real time — the same way across every connected platform.
How Live Shipping Rates Works in API2Cart
- basket.live_shipping_service.create — register a rate callback for a store
- Your callback accepts a POST request with basket data and returns live rates
- basket.live_shipping_service.list / delete — manage active services
- order.preestimate_shipping.list — retrieve preestimated shipping methods for an order
Example request
{
"name": "Custom Carrier Rates",
"callback": "https://your-app.com/shipping/rates",
"store_id": "12345"
}
# Your callback receives basket data via POST
# and returns live rates back to checkout.
Use Cases for Live Shipping Rates
Freight & LTL Carriers
Quote real freight rates for oversized or palletized items.
Regional Rate Cards
Apply custom zone- or weight-based pricing your carrier API returns.
Multi-Carrier Comparison
Show the shopper live rates from several carriers at once.
Dynamic Promotions
Adjust shipping cost in real time based on cart contents or rules.
Frequently asked questions
The things people ask before using Live Shipping Rates.
How does the store get a live rate?
It calls your registered callback with basket data; your service returns the rate synchronously.
Can I register more than one rate service?
Yes — basket.live_shipping_service.list shows every active service per store.
What if my callback is slow or fails?
Design your callback to respond quickly — checkout is waiting on it synchronously, so treat it like any real-time API.
Is this available on every platform?
It works anywhere API2Cart supports baskets; coverage depends on the platform’s own checkout extensibility.
Bring your own shipping logic to checkout, on every platform you support.
Explore the full API2Cart API reference.
See the dedicated guide: Live Shipping Rates documentation.
How does the store get a live rate?
It calls your registered callback with basket data; your service returns the rate synchronously.
Can I register more than one rate service?
Yes — basket.live_shipping_service.list shows every active service per store.
What if my callback is slow or fails?
Design your callback to respond quickly — checkout is waiting on it synchronously.
Is this available on every platform?
It works anywhere API2Cart supports baskets; coverage depends on the platform’s own checkout extensibility.
