Inventory that agrees with itself.
Keep stock in perfect sync across all your Shopify stores — B2C, B2B, regional, multi-location — so the oversells, wipes, and duplicate catalogs from other sync apps can't happen to you.
Read-only to start · every write logged · nothing ever deleted
Request early access Free during beta · founder-run support · no card requiredLive demo
Click through it — it's interactive, not a video.
Retail → B2B Dry run
Try the sync
Then change stock on the Products tab and watch what the current mode does — in the Activity log and the Drift report.
Change stock on Retail below. A matched SKU is copied to B2B — instantly in Live mode, or held back (shown in red) in Dry-run and Paused.
Run matching first (Matches tab) so changes can sync.
| Product | SKU | Retail | B2B |
|---|
SKU matcher
Pairs variants by SKU and flags duplicates — which are never synced. Matching is about which SKUs line up between stores, not their quantities; quantity differences show on the Drift page.
No matches yet — run matching to build the report.
| SKU | Status |
|---|
→ Next: Matching is a one-time setup — this report only changes when your catalog does, not when you edit stock. To watch a sync happen, open Products, change a quantity, then check Activity and Drift.
Check drift
Compares "available" inventory on both stores for every matched SKU and flags any difference.
Result
Every sync decision — real or dry-run — is written here. Both stores read the same log; nothing happens silently.
| Time | SKU | Change | Result |
|---|
No sync activity yet. Change stock on the Products tab to see events here.
The idea
One quantity. Two stores. Always the same number.
A sale on one store, a restock on the other — and the count on both never disagrees, never goes negative.
The failure stories
If you run multiple stores, you know these stories
The three most repeated disasters across every multi-store sync app's one-star reviews:
A stock update races a sale, quantities go to −2, and you're emailing customers about orders you can't fill.
One ambiguous SKU match, and your catalog becomes a cleanup project measured in days.
Everything looks green until a customer orders something that sold out on the other store yesterday.
Paraphrased from public Shopify App Store reviews of leading sync apps, 2019–2026.
The guarantees
The three guarantees StockUnison is built on
Not features — invariants. Each one exists because a category of one-star review has to become impossible.
Atomic updates
A restock can never race a sale into negative inventory. Every quantity change lands whole, or not at all.
No silent drift
Every sync run is logged and verifiable. A drift report shows any mismatch — you see problems before your customers do.
Never destructive
No duplicate creation — and it never deletes anything, period. New connections start in dry-run, and disconnecting leaves both stores intact.
The mechanism
One-way, and it can't loop back
You pick one store as the source; the other copies it. Every change travels a single guarded path from source to destination — Store A to Store B below — and never the other way.
How it works
Three steps from two disagreeing catalogs to one verifiable truth
Connect your stores
Pair two stores with a one-time code. StockUnison maps SKUs and shows you exactly what matches — and what doesn't — before anything syncs.
Watch the dry run
Every would-be change appears in the activity log while nothing is written. Duplicate SKUs are never synced — ever. Flip to live when the plan matches reality.
Stay in unison
Real-time atomic sync from then on, with a live log and drift report proving your stores agree.
The proof
Printed proof of every write
Real or dry-run, every decision the sync makes is written to a log both stores can read. Nothing happens silently.
- 09:41:07HAT-00111 → 30APPLIED
- 09:41:07HAT-00130 → 29APPLIED
- restock met a live sale — serialized, landed wholeATOMIC
- 09:44:12MUG-10452 → 51APPLIED
- 09:47:58TEE-009duplicate SKUSKIPPED
- never synced — nothing deleted
- 09:52:33BAG-2017 → 6APPLIED
- 09:55:00DRIFT12/12 SKUs agreeVERIFIED
-
entries 6applied 4skipped 1lost 0nothing deleted · nothing silent
Built by the person who answers your email
A note from the founder. I'm Dmytro Yalanskyi, an independent developer. Before writing a line of StockUnison I read 2,603 reviews of every multi-store sync app on the Shopify App Store — including 163 detailed one-, two- and three-star stories of overselling, duplicated catalogs and wiped inventory.
StockUnison is the answer to those specific failures — and the first version is running today, syncing real stores with every decision logged and verifiable. Early access is free, and you'll be talking directly to the person who writes the code.
Questions you should ask a brand-new app
When can I actually use it?
The app is working today and heading into Shopify's app review; hand-onboarding of the first stores starts in August, and a few pilots can start sooner via direct install links. Requesting early access puts you in line — I onboard personally, in order, and you'll get a real date from a real person, not a waitlist autoresponder.
What does it cost?
Free during beta. After launch: flat, public pricing — the plan you start on is the plan you keep. No per-store creep, no feature ransoms, and beta merchants keep a lifetime discount.
What exactly does it sync?
Shopify to Shopify only, by design: inventory today, with products and prices next on the roadmap under the same guarantees. No marketplaces, no POS feeds — depth over breadth.
Why trust a new app with inventory?
Because it's built assuming you shouldn't. Connections start read-only, every write is previewed and logged, nothing is ever deleted without confirmation, and the drift report lets you verify — not trust — that your stores agree.
Two stores. One truth.
Join the early-access group and help decide what gets built first — with a free beta and a founder on the other end of every email.
Request early accessMail app didn't open? Just write to dmytro@stockunison.com