SentryKit

SentryKit is a real-time monitoring and alerting layer for Amazon sellers. Instead of reporting on what happened last week, it watches the things that quietly break revenue between reports: Buy Box ownership changing hands, a listing getting suppressed, backend fields being overwritten, fee changes landing on an ASIN, and account health signals moving in the wrong direction. When something changes, you get an alert with the context you need to act, including Amazon's stated reason where Amazon provides one.

Pricing is built around storefronts rather than catalog size. Every plan includes unlimited ASINs, unlimited orders, and every marketplace you sell in, so monitoring 50 SKUs and monitoring 50,000 cost the same. Starter covers two storefronts from $19 a month, Pro starts at $49 a month with five storefronts and adds competitor seller profiles on Buy Box events (seller name, location, storefront size, feedback rating, and whether the same competitor keeps reappearing). Additional storefronts drop in price as you add them, and an agency tier with white-label alerts, consolidated invoicing, and an uptime SLA starts around $199 a month. An API Partner tier at $1,200 a month covers unmetered API usage and custom event types.

The REST API and outbound webhooks are included on every plan, not sold as an enterprise add-on, with 25,000 API calls per storefront per month and no overage billing. That makes SentryKit straightforward to wire into an existing stack: alerts can be pushed into Slack, a ticketing system, or your own dashboards. It pairs naturally with a profit analytics platform like Nova, which explains the financial impact of what happened, while SentryKit tells you the moment it happens. A 30-day free trial is available with no card required.