Amazon Business Product Search API Restock Monitor

What I’m building I’m building an Amazon auto-checkout service. It is request-based: a browser is used once to sign in and hand over the session, and from then on everything runs as plain HTTP requests. Stock detection, add to cart, checkout and Place Order are all direct calls to Amazon’s own endpoints with a cookie jar and the browser’s identity. A headed browser only comes back when a human is needed, for a captcha, a sign-in challenge or a bank verification. What I need from you A better or cheaper stock signal than page polling. I want someone who has used the Amazon Business Product Search API in practice, or other sanctioned sources, and can say what onboarding, rate limits and data freshness really look like. A review of the add-to-cart and checkout pacing per account: where the current backoff leaves speed on the table, where it is about to get accounts flagged, and what to change. Every proposal gets tested in the harness and then measured on a real restock.