SentryKit

SentryKit is a real-time monitoring tool for Amazon sellers that tracks changes across listings on over 20 Amazon marketplaces. It solves the problem of sellers being unaware of critical listing changes—such as Buy Box losses, hijackers, listing suppressions, backend field edits, or fee increases—that can directly impact sales and margins. The service provides alerts with before-and-after values and context on whether a change affects profitability.

The platform monitors over 50 signals per listing, covering Buy Box and pricing, hijackers and competitors, listing health and suppression (including Amazon's stated reason), product content and backend fields, FBA fees, account health, and inventory velocity. It includes a COGS entry and floor-price calculator, a full REST API and outbound webhooks, and supports alerts in the marketplace's native language and currency. Pro plans add competitor seller profiles, margin-threshold alerts, and Buy Box history.

SentryKit is designed for private label sellers, agencies, and brands. Pricing is based on the number of connected storefronts (Amazon seller accounts), not on ASINs or marketplaces, which are unlimited on every plan. A 14-day free trial is available with no credit card required. Plans start with a Starter tier for one or two storefronts, a Pro tier for up to five storefronts with volume discounts for additional ones, and an API Partner tier for teams with custom pipelines. Annual billing offers a 20% discount.