Data providers and API partners
Most KDP123 tools run entirely in your browser. A few need live data, such as Amazon category lists or keyword phrases. Those requests go through KDP123's own server to a named provider, and the tool shows a "Data from" line saying who answered and what was sent.
How requests are handled
- No account, no cookies. KDP123 strips cookies and login headers before forwarding, and drops any cookie the provider sends back. Providers never see your KDP123 session, because there is none.
- Only what the tool needs. Each endpoint below lists exactly what it sends, for example the phrase you typed. Your other inputs stay in your browser.
- Read-only and rate-limited. Only GET requests to listed paths are forwarded, with a per-IP limit at our server and the provider's own daily limit.
- Fails quietly. If a provider is down, the part of the tool that needs it hides; the rest keeps working.
Current providers
KDPTopSame team as KDP123
KDPTop crawls Amazon.com bestseller and new release lists daily for about 11,000 Books and Kindle Store categories. Added 2026-11-10. Terms.
| Endpoint | What it returns | Sends | Limit | Used by |
|---|---|---|---|---|
| GET /api/kdptop/placement/resolve | Categories for a book by ASIN, ISBN or Amazon link | The ASIN, ISBN or link you paste and the format | 10 lookups a day per visitor | Category finder |
| GET /api/kdptop/placement/recommend | Categories that match a description of a book | The description you type and the format | 30 lookups a day per visitor | Category finder |
| GET /api/kdptop/category/{node_id} | Latest snapshot of one Amazon category | The category number | 60 lookups a day per visitor | Category finder |
| GET /api/kdptop/keywords/suggest | Related search phrases from KDPTop's keyword library | The seed phrase you type | 30 lookups a day per visitor | Keyword builder |
| GET /api/kdptop/bsr-curve | The BSR-to-sales curve KDPTop uses | Nothing | Cached for an hour | BSR to sales |
| GET /api/kdptop/today | Today's breakout new book and list counts for the home page | Nothing | Cached for ten minutes | Home page "Today on KDP" strip |
Plugging in your API
If you run a KDP data service and want a free KDP123 tool to use it, the API has to meet all of these:
- Works without login. Visitors never sign up or connect an account to use the tool.
- No tracking of our visitors. No cookies, fingerprinting or resale of queries. We send only the query itself and a forwarded IP for your rate limit.
- Attribution and a link out are fine; a paywall is not. The tool shows your name and an "Open in" link to your site. The core answer has to be usable on KDP123.
- Free, and no effect on rankings. We do not pay for data and providers do not pay us. Providing data never changes how your own listing is ordered or described.
- Stated limits. Tell us the daily limit per visitor and the response cache time so the tool can say them.
- Sourced numbers. Explain how the data is collected, in a sentence we can show next to it.
Each provider gets a /api/p/<provider>/ path on our server, a data/providers/<provider>.yml entry and a forwarding rule; the templates are in the repository. Email hello@kdp123.com with your API docs.
Calling KDP123 itself
The directory is open data: tools.json and tools.csv (CC BY 4.0). Every calculator's formula and URL parameters are in calculators.json, so a link such as /free-tools/royalty-calculator/?price=12.99&pages=300 opens a filled-in result.