Integrations
SellerAmp has no API we can use — Analyze with SAS opens a lookup in a tab (sign in there). ASIN→UPC is local-first (catalog cache, order/email harvest, upcitemdb trial) — run npm run ids:upc or job ids.asin_upc. Keepa is optional paid price history, not required.
ASIN → UPC (optional extras)
Primary path is free and local — no keys needed. Optional keys below are never required; leave blank. upcitemdb trial runs automatically when not rate-limited.
Amazon SP-API
eBay Sell APIs
App auth (hosting)
Set a password here, then run with EWS_REQUIRE_AUTH=1 and EWS_AUTH_TOKEN (see docs/hosting.md).