Service companies run their scheduling, customers and invoicing in ERPNext, but the technician standing at a customer site has no good way to interact with it. The ERPNext desk is a heavy back-office UI that assumes a stable connection and a full-size screen; in a basement, a rural site or an underground car park there is often no signal at all. So dispatchers phone jobs through, technicians scribble notes and photograph work on their personal phones, and someone re-keys it into ERPNext hours or days later. Job status, proof-of-service photos, signed completion sheets and arrival/departure times all live outside the system until then, which delays invoicing and leaves disputes with no audit trail.

ECOSIRE builds a dedicated offline-first PWA that runs in the technician's mobile browser and installs to the home screen — no app-store submission, no separate native codebase to maintain. It ships as a proper Frappe app (field_service_pwa) with its own module, so it upgrades cleanly with bench and never patches ERPNext core. The front end is service-worker-backed: the app shell and each technician's assigned jobs are cached locally, form entries are written to IndexedDB while offline, and a background sync queue replays them to ERPNext the moment connectivity returns. We add conflict handling on the modified timestamp so a stale local copy never silently overwrites a dispatcher's change.

Under the hood the data model is real ERPNext. We add DocTypes such as Field Job, Job Visit Log and Job Attachment (or map onto your existing Maintenance Visit / Issue / Work Order flow where you already use it), linked to Customer, Item and Sales Invoice so a completed job can flow straight into billing. All reads and writes go over the Frappe REST API plus a small set of @frappe.whitelist() methods for the batched sync endpoint and the signed-completion write. Photos and the captured signature (a base64 PNG from a canvas) are stored as private File records against the job. GPS check-in/out writes a timestamped, geocoded Job Visit Log row; a hooks.py doc_events handler on submit stamps duration and flips the job status, and a scheduler event nightly flags visits that never checked out.

Access is governed by ERPNext permissions, not a bolt-on: technicians get a dedicated Role and Role Profile so a field user only ever sees their own assigned jobs and customer records, enforced by permission queries rather than UI hiding. Client scripts drive the on-device validation and the ERPNext-side kanban dispatch board, and every field action lands in the standard document timeline for a full audit trail. The whole app targets Frappe/ERPNext v15 and v16.

Because this is build-to-order, nothing is a pre-packaged download. We start with a short scoping call to map your exact dispatch workflow, the fields your technicians must capture and how completed jobs should hit invoicing. We build against that scope, deliver to a staging site for your UAT, then install on your production ERPNext with a rollback plan. Typical delivery is one working week from confirmed scope, and you receive the full source and git repository so nothing is locked to us.