Research a list of items

For each item, send an eBay sold listings, Poshmark sold listings or Mercari sold listings search with specific keywords. Give each search its own Idempotency-Key, and reuse that key only when you retry the same search.

curl -G https://api.soldgraph.com/v1/ebay/sold \  -H "Authorization: Bearer $SOLDGRAPH_KEY" \  --data-urlencode "q=sony wh-1000xm5" \  -d page=1

Keep only a few searches pending at a time. Each account has a cap on pending searches, and going over it returns 429 too_many_pending. Long-poll each job with ?wait=20 and send the next search when one finishes. The client in Rate limits does this for one search.

Store result.data with collected_at and each row's link. Any median, range or valuation is your own calculation, not an API field. One page isn't a full history, and displayed prices can differ from what the buyer paid.

To turn the rows into a suggested price in your app, see eBay pricing API for your app. To work in a spreadsheet instead, see Google Sheets.