ERPNext handles quotations, sales orders, and stock beautifully, but the moment a warehouse team needs a real UPS rate at pick-and-pack time, native ERPNext runs out of road. Out of the box there is no UPS OAuth connection, no negotiated-rate quote on the Delivery Note, no label to print, and no tracking status flowing back into the document. Teams end up re-keying addresses into UPS WorldShip or ups.com, copying tracking numbers back by hand, and reconciling shipping cost after the fact — slow, error-prone, and impossible to audit against the sales order.

We build a proper Frappe app (installed with bench get-app / bench install-app) that lives inside ERPNext rather than bolting on beside it. A UPS Settings single DocType holds your OAuth 2.0 client credentials, account number, and rate/label preferences, with the client secret stored encrypted in the site config. A whitelisted server method authenticates against the UPS OAuth API, caches the bearer token until expiry, and calls the Rating, Shipping, Track, and Pickup endpoints. Doc events registered in hooks.py extend the standard Delivery Note and Shipment DocTypes: on submit we request a live negotiated-rate quote for the parcel's weight, dimensions, and destination, then persist the returned service level, cost, and UPS tracking number onto custom fields.

Label generation is a one-click action. A client script adds a "Get UPS Label" button that calls the whitelisted method, receives the label in your chosen format (GIF, ZPL for thermal printers, or PDF), and attaches it to the document as a File. Paperless commercial invoice upload is supported for international shipments so customs documents ride along with the shipment request. A scheduler event (registered under scheduler_events in hooks.py) polls the UPS Track API on an interval and writes time-in-transit and delivery status back onto the Delivery Note, so ops and customer service see live status without leaving ERPNext. Void Shipment and Pickup Request are exposed as guarded server actions with their own role permissions.

Because this is build-to-order, nothing is a black box. We scope the exact services, DocTypes, and print formats you need on a short call, build against your UPS developer account and ERPNext version (Frappe/ERPNext v15 or v16), and validate everything on a staging site before go-live. Typical delivery is one working week from confirmed scope depending on how many services (rating, labels, tracking, void, pickup, paperless invoice) and print/ZPL formats you require. You receive the installable source, the git repository, documentation, and a post-go-live support window — this is not an instant Marketplace download, it is a system engineered to your shipping process and handed over to you.