BuyWhere vs OLX Poland

BuyWhere runs a live product-search API backed by a real, large product catalog spanning merchants across seven Southeast Asian and North American markets, purpose-built for AI shopping agents. Access is gated by a Bearer API key with a published free/Starter/Pro/Enterprise pricing ladder rather than an open, unauthenticated feed. Its CORS policy only serves an Access-Control-Allow-Origin header to allow-listed origins, so arbitrary browser-side callers get no such header even though the API answers preflight requests.

OLX Poland's Partner API lets approved integrators create and manage classified-ad listings and handle buyer/seller messaging programmatically. Access runs on an OAuth2 client-credentials flow, confirmed live by an invalid_client error from the real token endpoint, and the older v1 REST resource has been explicitly deprecated in favor of this OAuth-secured surface. Developer access comes through an application and approval process rather than a published self-serve fee.