Your Buy Box lost to a competitor. A hijacker on your listing. Amazon changing your description. A listing search suppressed — with Amazon's reason. A fee that quietly went up. SentryKit catches it in real time and tells you which changes are actually costing you money.
14 days free, no card. Then $19/mo · unlimited ASINs · every marketplace · See pricing →
🇬🇧 🇩🇪 🇫🇷 🇮🇹 🇪🇸 Alerts in your language, prices in your currency — across 20+ Amazon marketplaces.
Selling in the UK and across Europe, or in North America? SentryKit monitors every listing in every marketplace you sell in — and speaks your sellers' language.
20+ marketplaces · more being added regularly
The best sellers don't react faster — they know first, and they know what they're looking at. SentryKit watches every signal on your listings in real time and delivers each one with context: what changed, who's on the listing, and what it means for your margin. A hijacker worth fighting, or a zero-feedback seller who'll be gone by the weekend. A real Buy Box loss, or a suppression carrying Amazon's own stated reason — which no price cut will clear. Half the competitors who undercut you aren't worth matching, and SentryKit tells you which half. You act on facts, the moment they matter — not days later, from the revenue.
Won, lost, or suppressed — with the exact price gap, competitor fulfillment type, and whether matching is above your floor.
New seller on your ASIN profiled instantly — feedback rating and count, FBA/FBM, Prime — so you know a real threat from noise.
Title edited, main image swapped, category changed, listing suppressed. When Amazon gives a reason, you see Amazon's own words and the exact field it named. When Amazon gives no reason, we say so rather than guess.
FBA stock tracked against your live sales velocity — including units in transit. Get alerted before stock depletion hits your Buy Box eligibility, not after.
The backend fields that change without anyone telling you — compliance and safety, country of origin, hazmat class, backend search terms, list price. In plain English, with the raw Amazon field name and the before and after.
Account Health Rating, Order Defect Rate, late shipment and valid tracking, policy violations and complaints — the metrics that decide whether you keep selling, not just whether you win a listing.
The precise dollar amount between your price and the Buy Box winner. Not an estimate — the exact number, so you know whether a $1.50 move wins it back or a $6 drop is needed.
Set your minimum based on landed cost. Every single alert shows whether matching to win the Buy Box is above your floor or below it. Intelligence, not autopilot.
FBA or FBM, feedback score, fulfillment type — for every competing offer. A zero-feedback FBM seller undercutting by $11 is a completely different situation from an established FBA brand $1.50 below you.
Every signal, one platform — the coverage your listings have been missing.
Most tools watch one or two signals. SentryKit is Amazon listing monitoring that covers everything which can quietly cost you — fees and margin, Buy Box and pricing, account health, suppression with Amazon's own stated reason, the backend listing record, product content, reviews, rank, inventory and hijackers — all at once, for every product in your portfolio.
What you need to watch depends on how you sell. Private-label brands face hijackers and listing tampering. Wholesale fights a crowded offer landscape. Online arbitrage runs thin margins at high velocity. Agencies juggle all of it across many accounts.
Your biggest threats are hijackers, unauthorised resellers, and listing changes you didn't make. When a hijacker appears on your ASIN, you need their feedback rating, feedback count, and fulfillment type in the same alert — not just that they're there.
You're competing on someone else's ASIN with sellers who know the listing as well as you do. Knowing their FBA status, account standing, and how their price compares to your floor changes your entire pricing strategy.
OA is high velocity with tight margins. Amazon inventory alerts that catch stock depletion early and sales velocity drops that signal a Buy Box problem before your payout report does.
Managing multiple seller accounts means listing health across all of them — not 15 separate dashboards. Every issue flagged before a client notices a revenue dip.
Start with 14 days free. Every plan includes all 50+ signals, unlimited ASINs, every marketplace, and the full API and webhooks. Your price is based on one simple thing — how many storefronts you run.
| Storefronts | Per storefront | Volume saving |
|---|---|---|
| 1–5 | included in base | — |
| 6–15 | +$19 each | — |
| 16–30 | +$14 each | ~26% lower |
| 31–60 | +$10 each | ~47% lower |
| 61+ | +$7 each | ~63% lower |
Managing many client accounts? Custom volume pricing with white-label alerts, consolidated invoicing, an uptime SLA, and a dedicated onboarding partner — from ~$199/mo.
No hard cutoffs, ever. Unlimited ASINs, orders and marketplaces on every plan — only storefronts affect your price. The API and webhooks are included on every plan, and there are no overage charges: if you pass your monthly call allowance we slow you down for the rest of the cycle, we never bill you. Your coverage keeps running through Q4 peaks and flash sales.
50+ signals on every listing. Full context on every alert, your price floor always visible. 14 days free, then $19/mo. Cancel anytime.
Start free — 14 days, no card →