Five layers, each scored 0–20, ordered "from DNS on down" — a site can't be understood by an AI model if crawlers can't reach it or are told to stay out.
L1DNS & transport
DNS resolution, HTTPS availability, TLS certificate validity, redirect chains, and canonical host handling.
L2Crawler policy
robots.txt parsing against 13 tracked AI crawlers (GPTBot, ClaudeBot, PerplexityBot, OAI-SearchBot…), blanket disallows, X-Robots-Tag headers.
L3Discovery
llms.txt, XML sitemap discovery and parsing, feeds, and other machine-readable maps.
L4Comprehension
JSON-LD structured data, Open Graph metadata, semantic HTML, and detection of empty JavaScript shells that crawlers can't read.
L5Agent-commerce readiness
Emerging, optional signals: agent manifests, machine-readable catalogs, and crawlable purchase paths. Informational only — absence is normal today.
Free vs FullTwo scan depths
The free Quick Scan covers L1–L2 (reachability + AI-crawler policy). The Full Deep Scan runs all five layers and costs 100 credits.