Saudi businesses in the ZATCA integration phase have a hard problem that ERPNext core does not solve: every standard tax invoice must be cleared with ZATCA in real time before it is valid, and every simplified invoice must be reported within 24 hours — both as signed UBL 2.1 XML carrying a cryptographic stamp and a TLV-encoded QR code. Stock ERPNext prints a Sales Invoice and can compute VAT, but it has no concept of a CSID, no UBL generator, no XAdES signing, no PIH invoice-chaining, and no client that talks to the Fatoora clearance and reporting APIs. Teams that try to bolt this on with print formats and manual portal uploads end up with rejected invoices, broken invoice hash chains, and audit exposure.

ECOSIRE builds a dedicated Frappe app (its own hooks.py, module, and DocTypes) that plugs directly into your existing ERPNext Sales Invoice workflow. We add configuration DocTypes for your ZATCA credentials and CSID/device state, and a per-invoice ZATCA E-Invoice DocType that stores the generated XML, the invoice hash, the previous-invoice hash (PIH), the returned clearance UUID, and the ZATCA warning/error payload. A doc_events hook on Sales Invoice on_submit builds the UBL 2.1 document from your invoice, its items, and tax lines, signs it, and — depending on whether the invoice is standard (B2B) or simplified (B2C) — either calls the clearance endpoint synchronously or queues the invoice for reporting via a scheduler_events background job, so a slow ZATCA response never blocks your cashiers.

Technically, the app implements the full Phase-2 cryptographic chain: ECDSA key generation, CSR creation, compliance CSID and production CSID onboarding against ZATCA's APIs, XAdES-B enveloped signing of the UBL invoice, the SHA-256 invoice hash, the PIH linkage that chains each invoice to the last, and the base64 TLV QR code embedded in your A4 and thermal print formats. Communication uses ERPNext's server-side request layer with retries and full logging; whitelisted methods (exposed over the Frappe REST API) let you re-trigger clearance, fetch status, and re-onboard a device. Role profiles and DocType permissions keep credential and CSID management restricted to a ZATCA Manager role while accounts users simply submit invoices as they always have.

Because this is build-to-order, we start from your real ERPNext data — your company tax registration, invoice volume, B2B vs B2C mix, and existing customizations — and tailor the app to it rather than shipping a one-size-fits-all connector. After a short scoping call we confirm scope, then build, test on a staging clone of your site, run UAT with your finance team against ZATCA's sandbox, and cut over to production with a rollback plan. Typical delivery is one working week from confirmed scope. You receive the full source code and git repository, so you are never locked to us; we hand it over and back it with a post-go-live support window on Frappe/ERPNext v15 and v16.