Illustrative previewA build-to-order Business Central AL extension that lets your point of sale keep selling through internet
outages by caching transactions locally, then idempotently replaying and reconciling them to BC the moment connectivity returns.
What is Offline-First POS Sync Engine?
A build-to-order Business Central AL extension that lets your point of sale keep selling through internet outages by caching transactions locally, then idempotently replaying and reconciling them to BC the moment connectivity returns. Built to order by ECOSIRE for Dynamics 365 BC (build-to-order) — indicative price from $999.00 USD; request a quote for a scoped proposal.
Key Features
Built to order, done for you
No DIY setup — a working app, built, installed and supported by ECOSIRE.
- 1
You order
Start with a one-time build price. We scope it with you at kickoff.
- 2
We build & install
ECOSIRE builds, configures and installs it on your Dynamics 365 Business Central.
- 3
Go live + support
You go live in about one working week, with two weeks of go-live support. Defects in the code we deliver are fixed free of charge.
About this Product
Sell through the outage, reconcile when you're back
Most Business Central POS integrations assume a live connection. When the link drops, the register either freezes or — worse — staff fall back to paper and you reconcile by hand later. The Offline-First POS Sync Engine removes that failure mode. It is a build-to-order per-tenant AL extension that ECOSIRE designs, builds, installs and supports directly on your Business Central environment (online or on-prem) — not an instant AppSource download.
How it works
Each register holds a local transaction cache plus a point-in-time snapshot of item prices, active promotions and on-hand inventory pulled from BC. Checkout continues fully offline against that snapshot. The moment connectivity returns, a queued sync worker replays every offline transaction into Business Central through the BC REST/OData v4 API and posts the resulting sales documents.
Posting is idempotent: each offline transaction carries a client-generated unique key, and an AL event subscriber on the sales posting routine rejects any replay that has already landed — so a flaky connection that retries three times still produces exactly one sales entry, never duplicates.
Built into Business Central properly
We deliver real BC objects, not a bolt-on: table extensions for the offline queue and sync ledger, page extensions surfacing a per-device sync-status dashboard, a Job Queue entry that drains the replay queue on a schedule, dedicated permission sets, and event subscribers for conflict-free reconciliation. Optional Dataverse / Power Platform wiring lets you alert on stuck transactions from Power Automate.
ECOSIRE handles the AL development, the per-tenant install, UAT against your live catalog, and ongoing support and BC version-update compatibility. You get the source-aligned extension running in your own tenant — honestly scoped, honestly delivered.
What you get
- A per-tenant Business Central AL extension (.app) built to your catalog, register topology and posting setup, installed in your environment
- Table extensions for the offline queue and sync ledger, plus page extensions for the per-device sync-status dashboard
- Event subscribers implementing idempotent sales posting and conflict-safe reconciliation
- A configured Job Queue entry for scheduled, retry-aware replay of the offline queue
- Permission sets for cashier, store-manager and sync-administrator roles, assigned during install
- Optional Dataverse / Power Automate flow for stuck-transaction alerting, configured to your notification channel
- UAT against your live price, promotion and inventory data, with a documented sign-off checklist
- Admin runbook plus knowledge transfer covering monitoring, reprocessing stuck transactions and handling flagged conflicts
Who this is for
Multi-store retail operations manager
Runs several branches on Business Central where at least one site has unreliable broadband. Needs every till to keep selling during outages and to trust that the day's sales reconcile into BC exactly once, with a clear dashboard showing which registers are behind.
Pop-up and market vendor
Sells at fairs, markets and temporary locations where Wi-Fi and mobile signal are intermittent or absent for hours. Wants checkout that never stops, working off a local price and promo snapshot, then auto-syncs to BC the instant a connection appears.
Franchise IT / BC administrator
Owns the Business Central tenant across franchised stores and is accountable for clean financials. Needs idempotent posting, per-device permission control, an auditable sync ledger and stuck-transaction alerts rather than late-night manual reconciliation.
How Offline-First POS Sync Engine Compares
| Criterion | ECOSIRE | Custom Build | Competitor | Dynamics 365 Business Central Native |
|---|---|---|---|---|
| Continues selling fully offline during an internet outage | Included | Partial support | Partial support | Not included |
| Idempotent posting that prevents duplicate sales on retry | Included | Partial support | Partial support | Not included |
| Per-device sync-status dashboard and stuck-transaction alerts | Included | Partial support | Partial support | Not included |
| Built as native BC objects (AL extensions, event subscribers, Job Queue, permission sets) | Included | Included | Partial support | Included |
| Tailored to your exact catalog, register topology and conflict rules | Included | Included | Not included | Not included |
| Installed and supported on your tenant with BC version-update compatibility | Included | Partial support | Partial support | Included |
| Auditable sync ledger linking each offline sale to its BC document | Included | Partial support | Partial support | Not included |
| No in-house AL development team required to build or maintain it | Included | Not included | Included | Included |
Frequently Asked Questions about Offline-First POS Sync Engine
How long does delivery take, and what is the process?
This is a build-to-order extension, not an instant download. After a short scoping call we confirm your register topology, catalog size and BC version, then build and install the per-tenant AL extension. Typical delivery is one working week depending on how many register configurations and conflict rules you need. The flow is: scope and fixed quote, build, install into a sandbox, UAT against your live price/promo/inventory data, then promotion to production with sign-off.
How is ongoing support and Business Central compatibility handled?
Because we install the extension in your own tenant, ECOSIRE provides post-launch support and keeps it compatible across Business Central updates. Microsoft ships major BC releases twice a year; we test the extension against each relevant update and ship any required AL fixes under your support agreement. Support covers reprocessing stuck transactions, tuning the Job Queue cadence and offline caps, and adjusting conflict rules as your catalog evolves. Support terms and response times are agreed in writing before go-live.
Will offline replays ever create duplicate sales in Business Central?
No. Every offline transaction carries a client-generated unique key. An AL event subscriber on the sales posting routine checks that key against the sync ledger before posting, so a transaction that the connection retries multiple times still produces exactly one BC sales entry. Failed or partial replays are flagged in the dashboard for review, never silently re-posted.
What happens to inventory and pricing if they changed in BC while a register was offline?
Each register sells against a snapshot captured when it was last online. At replay time the engine detects drift — for example a price change or an item that went out of stock centrally — and flags those transactions for store-manager review rather than overwriting silently. You decide the conflict policy during scoping (accept-as-sold, adjust, or hold), and we encode it into the reconciliation event subscribers.
Does this run on Business Central online (SaaS) or on-premises?
Both. The extension is delivered as a per-tenant AL extension that installs into a BC SaaS environment or an on-premises deployment. It integrates through the standard BC REST/OData v4 API and standard BC objects (table/page extensions, event subscribers, Job Queue, permission sets), so it lives inside your environment under your governance rather than depending on external middleware.
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Offline-First POS Sync Engine
A build-to-order Business Central AL extension that lets your point of sale keep selling through internet outages by caching transactions locally, then idempotently replaying and reconciling them to BC the moment connectivity returns.
- Local transaction cache per register so checkout continues fully offline with zero blocked sales during an internet or VPN outage
- Offline price, promotion and on-hand inventory snapshot synced down from Business Central, refreshed automatically whenever the register is online
- Automatic conflict-free replay and reconciliation to BC the moment connectivity returns, draining the queue oldest-first
- Idempotent posting to Business Central via a client-generated unique transaction key enforced by an AL event subscriber on the sales posting routine — no duplicate sales entries on retries