# SecondDoor > SecondDoor scans a website twice, once as a human visitor and once as an AI agent, and scores how far each one gets through the funnel. The difference between the two scores is the Door Gap. Basic scans are free, and every report is public and permanent. Full methodology in one file: https://www.seconddoor.io/llms-full.txt ## Methodology - [How SecondDoor scores a site](https://www.seconddoor.io/methodology): the ten dimensions, the arithmetic, and what each band means. - [Machine discoverability](https://www.seconddoor.io/methodology/machine_discoverability): Whether a retrieval system can find and read you at all. - [Programmatic onboarding](https://www.seconddoor.io/methodology/programmatic_onboarding): Whether an agent can get working access without a human. - [Pricing legibility](https://www.seconddoor.io/methodology/pricing_legibility): Whether total cost can be computed from published numbers. - [Agent-aware instrumentation](https://www.seconddoor.io/methodology/agent_aware_instrumentation): Whether you publish anything built for machine callers. - [Machine-fetchable trust](https://www.seconddoor.io/methodology/machine_fetchable_trust): Whether terms, security and status are readable as text. - [Commercial rails](https://www.seconddoor.io/methodology/commercial_rails): Whether a purchase can complete without a sales call. - [Steps to first value](https://www.seconddoor.io/methodology/steps_to_first_value): How far a new visitor travels before something useful happens. - [Required fields](https://www.seconddoor.io/methodology/required_fields): How much you ask for before you give anything back. - [Verification walls](https://www.seconddoor.io/methodology/verification_walls): How many gates stand between intent and access. - [Error recovery](https://www.seconddoor.io/methodology/error_recovery): What happens when someone gets it wrong. ## Guides - [The agent readiness tools of 2026, compared](https://www.seconddoor.io/guides/agent-readiness-tools): Every scanner and monitor worth knowing about, free ones included, what each actually measures, and how to pick. SecondDoor is in the list on the same terms as everyone else. - [Should you block AI agents? A straight answer](https://www.seconddoor.io/guides/blocking-agents): Blocking automation stops scrapers and card testers. It also stops the buyers arriving from ChatGPT and Claude. How to keep one without losing the other. - [Agent checkout in 2026: what is real and what to publish](https://www.seconddoor.io/guides/agentic-checkout): UCP, ACP and AP2 explained without the hype, and the one file a scanner can actually verify today. - [Making products legible to a machine](https://www.seconddoor.io/guides/product-feeds-for-agents): Product and Offer markup, why feeds are the new storefront, and what an agent does when your prices are only pixels. - [llms.txt: worth writing, not worth believing in](https://www.seconddoor.io/guides/llms-txt): What belongs in an llms.txt, and the evidence on whether anything reads it. Cheap insurance, not a strategy. - [Pricing an AI agent can actually read](https://www.seconddoor.io/guides/agent-readable-pricing): Why prices that need JavaScript are invisible to buyers that do not run it, and what to publish instead. - [Signup flows an agent can complete without a human](https://www.seconddoor.io/guides/signup-for-agents): Verification walls, required fields, and what stops an autonomous buyer at the door. - [Making your product discoverable to AI agents](https://www.seconddoor.io/guides/mcp-discovery): MCP manifests, agent-aware robots rules, and what discoverable actually means to a machine. - [Trust signals a machine can actually fetch](https://www.seconddoor.io/guides/machine-fetchable-trust): security.txt, terms, and status pages that answer a fetch rather than a browser. ## Compare - [SecondDoor against the field](https://www.seconddoor.io/vs): feature matrix across agent readiness and AI visibility tools, with honest guidance on when to choose the other tool. - [SecondDoor and Ora / is-agentic.com](https://www.seconddoor.io/vs/ora-is-agentic): The largest free agent-readiness scanner, distributed by Vercel. - [SecondDoor and Cloudflare Agent Readiness](https://www.seconddoor.io/vs/cloudflare-agent-readiness): Free protocol checks from the company that fronts a fifth of the web. - [SecondDoor and Lighthouse Agentic Browsing](https://www.seconddoor.io/vs/lighthouse-agentic-browsing): Chrome's own agent-readiness checks, inside the audit tool developers already run. - [SecondDoor and Proven AgentFriendly](https://www.seconddoor.io/vs/proven-agentfriendly): A public agent-readiness ranking of B2B software vendors. - [SecondDoor and Verity Score](https://www.seconddoor.io/vs/verity-score): Shopify-native AI visibility and buyer simulation with applied fixes. - [SecondDoor and Profound](https://www.seconddoor.io/vs/profound): The enterprise standard for AI answer visibility. - [SecondDoor and Peec AI](https://www.seconddoor.io/vs/peec): Fast-growing AI search analytics, priced for marketing teams and agencies. - [SecondDoor and Otterly.AI](https://www.seconddoor.io/vs/otterly): The affordable entry point to AI search monitoring, with a static readiness audit. ## Research - [The Door Gap Index](https://www.seconddoor.io/research/door-gap-index): quarterly statistics from the scan corpus, with cohort sizes. Also at https://www.seconddoor.io/research/door-gap-index.md as markdown and https://www.seconddoor.io/research/door-gap-index.json as JSON. ## Reports - [The Door Gap leaderboard](https://www.seconddoor.io/scans): every site scanned, ranked by the gap between its human and agent funnels. - [Ranked by agent door strength](https://www.seconddoor.io/scans?order=agent): the same pool, strongest agent funnel first. - Class leaderboards at /scans/{class} for b2b_saas, ecommerce, hybrid, content, services. - Score badges at https://www.seconddoor.io/badge/{domain} as SVG, always showing the domain's latest scores. - Each report is at /r/{slug} as a page, /r/{slug}.md as markdown, and /api/reports/{slug} as JSON. ## API - [API documentation](https://www.seconddoor.io/docs) - [OpenAPI specification](https://www.seconddoor.io/openapi.json) - [MCP server](https://www.seconddoor.io/api/mcp): tools to fetch a report, run a scan, and read the methodology. - [MCP manifest](https://www.seconddoor.io/.well-known/mcp.json) ## Pricing - [Plans and prices](https://www.seconddoor.io/pricing): Free $0, Starter $29, Pro $99, Agency $249 a month, Dedicated agreed in conversation. - Paid plans are monthly subscriptions, billed in US dollars, renewing automatically until cancelled. No minimum term and no cancellation fee. - Cancel at any time and keep paid features until the end of the period already paid for. Subscription fees are not refunded. - [Refunds and cancellation policy](https://www.seconddoor.io/refunds) ## About - SecondDoor is operated by Growthfolio, LLC, 6 Orchard Street, Concord, NH 03301, United States. - Support: support@seconddoor.io. Billing: billing@seconddoor.io. - [The scanner](https://www.seconddoor.io/bot): what it fetches, how it identifies itself, how to block it. - [Support](https://www.seconddoor.io/support): common questions about scans, accounts, billing and cancelling. - [Contact](https://www.seconddoor.io/contact): every address, and the postal address of the company behind the product. - [Index policy](https://www.seconddoor.io/index-policy): who is in the Door Gap Index, how to correct a score, and how to leave. Also at https://www.seconddoor.io/index-policy.md. - [Claim a domain](https://www.seconddoor.io/claim): prove you control a site to correct, rescan or withdraw it. - [Terms of service](https://www.seconddoor.io/terms) - [Privacy policy](https://www.seconddoor.io/privacy) - [Refunds and cancellation](https://www.seconddoor.io/refunds) - [Status](https://www.seconddoor.io/status)