SEO schema.org JSON-LD extraction and suggestion service for AI agents. Extracts or builds validated structured data from any URL. 200+ types (Product, LocalBusiness, Article, Event, etc). AI suggests the optimal schema type when site markup is sparse or missing. Fast-paths for 30+ publishers at zero LLM cost. x402 payments are non-refundable. Known-difficult domains (CAPTCHA, auth walls) are auto-rejected before payment. Call GET /check?url=TARGET first for a free difficulty assessment.