Warehouse teams running ERPNext quickly hit the limits of manual data entry. Stock Entry, Purchase Receipt, and Delivery Note forms were designed for a desk, not for a picker walking aisles with a scan gun. Item codes get keyed wrong, Pick Lists are worked off printed paper and reconciled hours later, and cycle counts mean someone transcribing shelf tallies into a spreadsheet before a Stock Reconciliation is ever created. ERPNext core does support a barcode field and the built-in Point of Sale scan box, but there is no purpose-built mobile flow for receiving against a PO, picking against a Pick List, bin-to-bin transfers, or blind counts — and nothing that keeps working when the warehouse Wi-Fi drops behind a rack of steel shelving.

We build a proper Frappe app — its own module with custom DocTypes, hooks.py doc events, whitelisted API methods, and a mobile-first UI — installed on your own ERPNext bench. Scanning happens through the device camera (using a JS barcode decoder) or any Bluetooth/USB HID scan gun, and every scan resolves against your existing Item, Item Barcode, Batch, and Serial No records via whitelisted @frappe.whitelist() methods over the Frappe REST API, so there is no shadow inventory and no second source of truth. Scan-to-pick walks the operator through an ERPNext Pick List line by line, validating each scan against the expected item, quantity, and (where used) batch/serial. Scan receiving matches units against open Purchase Receipt / Purchase Order lines. Transfers and cycle counts post real Stock Entry and Stock Reconciliation documents through the standard submit workflow, so ledger entries, valuation, and audit trail stay exactly as ERPNext expects.

Reliability is designed in. Server-side hooks.py doc events enforce your posting rules, client scripts drive the on-device validation, and an offline queue buffers scans in local storage when connectivity drops and replays them through an idempotent sync endpoint once the device is back online — with conflict handling so a stale queue can't double-post. Permissions ride on ERPNext's own role and Role Profile model plus Warehouse-level restrictions, so a picker only ever touches the documents and stock locations they are entitled to, and every posted document carries the operator's user and timestamp. Optional scheduler events can reconcile the queue, flag stuck scans, or push a daily count-variance report. The app is built and tested against Frappe/ERPNext v15 and forward-compatible with v16.

Because this is build-to-order, nothing ships until we understand your warehouse. We start with a scoping call to map your receiving, picking, and counting flows, your scanner hardware, and whether you use batches, serials, or multi-warehouse bins. From confirmed scope, typical delivery is one working week: we build against a staging copy of your bench, run UAT with your operators on real documents, then install on production with a rollback plan. You receive the full source, the git repository, install and configuration docs, and a post-go-live support window — no black box, no lock-in.