{"ok":true,"kind":"lesson","integrity":{"knowledge":"free","capability":"paid_x402_optional","rule":"Every concept on a path is fully teachable without purchase. Skills are optional implementations, never required reading.","display":"Learn free. Buy only if you want a ready-to-run sealed pack."},"lesson":{"schema_version":"lvl-knowledge-lesson-v1","id":"path-ae-05-machine-entry-points","category":"path","path_ids":["understand-agent-economy"],"title":"Machine entry points agents actually use","summary":"catalog.json, llms.txt, MCP, A2A agent cards, and shop — how agents discover a market without scraping SPAs.","body":"## Do not scrape the SPA grid\n\nHuman marketplaces often render with JavaScript. Agents should hit **static machine surfaces** instead.\n\n## Primary doors\n\n| Surface | Use |\n|---------|-----|\n| `/api/shop` | Single entry: next actions, featured, proof |\n| `/catalog.json` | Full inventory |\n| `/api/catalog?q=` | Search |\n| `/llms.txt` | Curated AI-oriented site map |\n| `/api/mcp` | MCP tools (search, challenge, purchase) |\n| `/.well-known/agent.json` | A2A Agent Card |\n| `/api/proof` | Confirmed unlocks |\n| `/learn/paths.json` | Knowledge paths (this hub) |\n\n## Free evaluation pattern\n\nEvery skill should expose `/skills/{id}/outline.json` before pay. If it does not, treat the listing as incomplete.\n\n## Takeaway\n\nDiscovery is multi-protocol on purpose: whatever dialect an agent speaks, it should find the market natively.","concepts":["machine-discovery","llms-txt","mcp","a2a","catalog"],"related_skills_optional":[{"skill_id":"agent-readable-seo-kit","name":"Agent-Readable SEO Kit","price_usd":4.99,"price_label":"$4.99 / unlock","summary":"Structure catalog.json and agent.json so shopping agents can rank listings.","outline":"https://lvlltd.com/skills/agent-readable-seo-kit/outline.json","challenge":"https://lvlltd.com/api/pay?skill=agent-readable-seo-kit","listing":"https://lvlltd.com/listings/agent-readable-seo-kit/","available":true,"optional":true,"label":"optional_implementation"}],"sort_order":50,"estimated_minutes":9,"last_updated":"2026-07-22T12:00:00.000Z","freshness":{"last_updated_at":"2026-07-22T12:00:00.000Z","days_since_update":0,"band":"fresh","score_0_100":95,"label":"Fresh","display":"Fresh · updated 2026-07-22 (0d ago)"},"integrity":{"knowledge_free":true,"skills_optional":true,"note":"This lesson is complete without purchasing any skill."},"related_bundles_optional":[],"url":"https://lvlltd.com/learn/lessons/path-ae-05-machine-entry-points/","updated_at":"2026-07-22T21:10:40.587Z"},"note":"Knowledge free. related_skills_optional are implementations, not requirements."}