Amazon Reverse ASIN API for Competitor Keywords

Send any Amazon ASIN and get the keywords it ranks and advertises for, with search volume, purchase rate, organic and sponsored positions and traffic share, as JSON.

Oct 14, 2026

What this API returns

A reverse ASIN lookup starts from a product instead of a keyword. You send an ASIN, and the endpoint returns the search terms that product appears for on Amazon — where it ranks organically, where its ads show, and how much of its traffic each term brings.

A real request for one cat water fountain in the US (ASIN B08NCDBT7Q), latest 30 days, returned 1,980 keywords. The top row:

Field	What it tells you	Value from the request above
`keyword`	The search term	`cat water fountain`
`searches`	Estimated monthly searches on Amazon	`724105`
`purchases`	Estimated purchases after that search	`30991`
`purchaseRate`	`purchases` ÷ `searches`	`0.0428`
`products`	Products competing for the term	`5702`
`trafficPercentage`	Share of this ASIN's exposure that comes from the term	`0.178`
`rankPosition.position`	Organic position on the results page	`16`
`adPosition.position`	Sponsored position	`3`
`naturalRatio` / `adRatio`	Organic versus sponsored share of the term's traffic	`0.809` / `0.191`
`bid` (`bidMin`–`bidMax`)	Suggested sponsored-products bid and range	`1.11` (`0.86`–`1.65`)
`badges`	How the ASIN appears: organic, Amazon's Choice, ads, …	`naturalSearching`, `amazonChoice`, `ads`

The arithmetic checks out: 30,991 ÷ 724,105 = 0.0428. Read together, the row says this product gets almost 18% of its exposure from one term, ranks 16th organically on it and pays to sit at position 3 as well. The full field list is in the reverse lookup reference.

Request example

curl --request POST \
  --url https://ecommercedataapi.com/v1/amazon/traffic/keyword \
  --header "Content-Type: application/json" \
  --header "X-API-Key: ${ECOMMERCE_DATA_API_KEY}" \
  --data '{
    "marketplace": "US",
    "asin": "B08NCDBT7Q",
    "month": "nearly",
    "page": 1,
    "size": 100
  }'

asin is required; marketplace defaults to US. Supported codes: US, UK, DE, FR, IT, ES, MX, CA, AU, JP, IN, AE, BR.
month takes nearly for the latest 30 days or yyyyMM for a past month.
size goes up to 100 rows per page. total tells you how many keywords there are in all; 1,980 above means 20 pages.
Results are sorted by traffic share, so the first page is usually the part that matters.

Reading the list

A reverse ASIN list is long, and not every term on it is worth acting on. In the same response:

cat brought 5% of the product's exposure, but its purchaseRate was 0.0031 — broad browsing, not buying.
A competitor's brand name appeared with 146,365 searches and a purchaseRate of 0.0031. Brand terms belong in your negative list, not your listing.
cat water fountain stainless steel had a purchaseRate of 0.0515, higher than the head term, and the product had no ad on it.

That last pattern is the usual reason to run a reverse lookup: a converting term where the competitor ranks organically but does not advertise, or the reverse. Filter on purchaseRate, trafficPercentage and whether adPosition is empty.

The response also includes stats, a count of the words that recur across the keywords on the page (fountain 6, water 6, cat 5 above), which is a quick read on how the product's traffic is described.

Common workflows

Map a competitor's traffic. Run the top three listings in a niche, merge the keywords and see which terms all of them depend on. Competitor analysis covers how to turn the difference into actions.
Find keyword gaps. Compare a competitor's list with your own ASIN's list. Terms they rank for and you do not are candidates for your listing and campaigns.
Build a keyword library. Combine reverse lookups with keyword research and deduplicate. See building a keyword library.
Summarise traffic sources. The traffic sources endpoint counts an ASIN's keywords by type (organic, Amazon's Choice, ads, video, brand) in one call.

Limits worth knowing

searches, purchases and bids are estimates, not Amazon figures. Positions are observed snapshots with an updatedTime; they move during the day.
The list covers terms where the product appeared in the first three result pages. A term where it ranks on page five is not there.
Different tools find different keyword sets for the same ASIN. Choosing a reverse ASIN tool gives a test you can run against any of them, including this one.
Each successful call consumes one billing unit per page.

FAQ

Does Amazon provide a reverse ASIN API? No. Amazon's own reports show search terms for your own brand only (Brand Analytics, Search Query Performance). Keywords for any other ASIN can only come from observed search results.

How is this different from keyword research? Keyword research starts from a term and tells you about demand. Reverse ASIN starts from a product and tells you which terms it actually wins. ASIN reverse keyword lookup explains what one request does and does not cover.

Can an AI agent use it? Yes. The endpoint is a tool on the remote MCP server, so an assistant can pull and summarise a competitor's keywords in one step.