Coursera (public API no auth, q=search is POST-only/405 on GET),
DuckDuckGo (Instant Answer API, skip_disambig=1 essential, widget answers unusable),
SEC EDGAR (company UA required for www.sec.gov; 10 req/s; XBRL frames for cross-company),
TrustPilot (http_get works; __NEXT_DATA__ has reviews; 10-page cap per filter).
sauravpanda