{"openapi":"3.1.0","info":{"title":"SiteSignal x402 API","version":"1.0.0","description":"Pay-per-call web utilities for AI agents: email-auth (SPF/DKIM/DMARC) audit, page to Markdown, SEO + llms.txt audit.","x-guidance":"Call any GET endpoint with its query parameter. Unpaid requests return 402 with an x402 v2 challenge (exact scheme, USDC on Base eip155:8453). Pay with any x402 client and retry. Inputs: domain=example.com or url=https://example.com.","contact":{"email":"alphaops@mail.grokbot.com","url":"https://sitesignal-api.vercel.app"}},"servers":[{"url":"https://sitesignal-api.vercel.app"}],"x-discovery":{"ownershipProofs":[]},"paths":{"/v1/email-security":{"get":{"operationId":"emailSecurity","summary":"Email-auth & deliverability audit for a domain","description":"Email-auth & deliverability audit for a domain: MX/provider, SPF (lookup count, all-qualifier), DMARC policy, DKIM on 18 common selectors, MTA-STS, TLS-RPT, BIMI, CAA. Returns A–F grade, score and copy-paste DNS fixes.","tags":["email","dns","dmarc","spf","dkim","deliverability","domain","security"],"x-payment-info":{"protocols":[{"x402":{}}],"price":{"mode":"fixed","currency":"USD","amount":"0.005"}},"parameters":[{"name":"domain","in":"query","required":true,"schema":{"type":"string"},"description":"Domain or URL, e.g. example.com"}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"domain":"stripe.com","grade":"A","score":95,"mailProvider":"Google Workspace","dmarc":{"policy":"reject"},"issues":[{"severity":"low","area":"mta-sts","message":"No MTA-STS policy.","fix":"Publish _mta-sts TXT…"}]}}}},"400":{"description":"Invalid input"},"402":{"description":"Payment Required (x402, USDC on Base)"}}}},"/v1/page-extract":{"get":{"operationId":"pageExtract","summary":"Fetch any public web page and return clean Markdown plus title, meta description, Open Graph, headings outline, JSON-LD types and link summary. Built for LLM agents (max 20k chars).","description":"Fetch any public web page and return clean Markdown plus title, meta description, Open Graph, headings outline, JSON-LD types and link summary. Built for LLM agents (max 20k chars).","tags":["scrape","web","fetch","markdown","extract","metadata","reader"],"x-payment-info":{"protocols":[{"x402":{}}],"price":{"mode":"fixed","currency":"USD","amount":"0.003"}},"parameters":[{"name":"url","in":"query","required":true,"schema":{"type":"string"},"description":"Absolute http(s) URL"},{"name":"maxChars","in":"query","required":false,"schema":{"type":"string"},"description":"Optional cap 1000-50000 (default 20000)"}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"url":"https://example.com/","status":200,"title":"Example Domain","headings":[],"wordCount":25,"markdown":"This domain is for use in documentation examples…"}}}},"400":{"description":"Invalid input"},"402":{"description":"Payment Required (x402, USDC on Base)"}}}},"/v1/seo-audit":{"get":{"operationId":"seoAudit","summary":"On-page SEO + AI-readiness audit of a URL","description":"On-page SEO + AI-readiness audit of a URL: 17 weighted checks (title, meta description, H1, canonical, indexability, OG/Twitter, alt text, JSON-LD, content depth, speed, robots.txt, sitemap.xml, llms.txt). Returns 0–100 score, grade and top 5 fixes.","tags":["seo","audit","website","marketing","llms.txt","meta"],"x-payment-info":{"protocols":[{"x402":{}}],"price":{"mode":"fixed","currency":"USD","amount":"0.01"}},"parameters":[{"name":"url","in":"query","required":true,"schema":{"type":"string"},"description":"Absolute http(s) URL"}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"url":"https://example.com/","score":41,"grade":"D","topFixes":["Add a 120–160 char meta description…"]}}}},"400":{"description":"Invalid input"},"402":{"description":"Payment Required (x402, USDC on Base)"}}}}}}