{ "openapi": "3.1.1", "info": { "title": "DNS + Certificate Explorer API", "version": "1.0.0", "summary": "DNS records, e-mail security, CAA, live TLS certificate and CT history for a domain.", "description": "Every endpoint performs the same calculation as the human page and returns inputs, result, units, assumptions, sources, warnings and computedAt. MCP endpoint: /mcp." }, "servers": [ { "url": "https://dnscertificateexplorer.usefulweb.site" } ], "paths": { "/api/v1/calculate": { "post": { "operationId": "calculate", "summary": "DNS records, e-mail security, CAA, live TLS certificate and CT history for a domain.", "description": "Resolves A, AAAA, CNAME, MX, NS, TXT, CAA and SOA records, analyses e-mail spoofing protection (SPF lookups and \"all\" policy, DMARC policy and reporting, MTA-STS), fetches the live TLS certificate from the domain's public IP (issuer, SANs, expiry, key, chain, TLS version, browser trust) and lists recent certificates from Certificate Transparency logs via crt.sh.\n\nMethodology:\n- DNS queries via the server's resolver: A, AAAA, CNAME, MX, NS, TXT, CAA, SOA for the domain and TXT at _dmarc. and _mta-sts..\n- SPF (RFC 7208): one record allowed, max 10 DNS-querying mechanisms, policy from the \"all\" qualifier. DMARC (RFC 7489): p=, pct=, rua=.\n- TLS: one connection to the first public IPv4/IPv6 address on port 443 with SNI; the certificate is verified against Node's trusted root store and the hostname (private addresses are never contacted).\n- Certificate Transparency: crt.sh JSON for the exact domain, latest 25 entries (deduplicated by serial, precertificates included).", "tags": [ "infrastructure" ], "x-mcp-tool": "dns_certificate_explorer", "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/DnsCertificateExplorerInput" }, "examples": { "example1": { "summary": "example.com", "value": { "domain": "example.com", "certificateTransparency": false } } } } } }, "responses": { "200": { "description": "Calculation result envelope.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/DnsCertificateExplorerResult" } } } }, "400": { "description": "Malformed JSON body.", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "422": { "description": "Invalid input (see errors[]).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "429": { "description": "Rate limit exceeded (see Retry-After).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } } } } }, "/api/v1/tool": { "get": { "operationId": "getToolDefinition", "summary": "Inputs, output schema and examples for this tool", "responses": { "200": { "description": "Tool definition.", "content": { "application/json": { "schema": { "type": "object" } } } } } } } }, "components": { "schemas": { "Problem": { "type": "object", "description": "RFC 9457 problem details. 422 responses include per-field `errors`.", "required": [ "type", "title", "status", "detail" ], "properties": { "type": { "type": "string" }, "title": { "type": "string" }, "status": { "type": "integer" }, "detail": { "type": "string" }, "code": { "type": "string" }, "errors": { "type": "array", "items": { "type": "object", "required": [ "field", "message" ], "properties": { "field": { "type": "string" }, "message": { "type": "string" } } } } } }, "DnsCertificateExplorerInput": { "type": "object", "additionalProperties": false, "properties": { "domain": { "title": "Domain", "type": "string", "maxLength": 253 }, "certificateTransparency": { "title": "Include Certificate Transparency history (crt.sh, slower)", "type": "boolean", "default": true } }, "required": [ "domain" ] }, "DnsCertificateExplorerResult": { "type": "object", "additionalProperties": false, "required": [ "schemaVersion", "tool", "computedAt", "inputs", "summary", "result", "units", "assumptions", "sources", "warnings", "presentation", "links" ], "properties": { "schemaVersion": { "type": "string", "const": "1.0" }, "tool": { "type": "object", "additionalProperties": false, "required": [ "id", "name", "version" ], "properties": { "id": { "type": "string" }, "name": { "type": "string" }, "version": { "type": "string" } } }, "computedAt": { "type": "string", "format": "date-time" }, "inputs": { "type": "object", "description": "Normalised inputs actually used, including applied defaults." }, "summary": { "type": "string" }, "result": { "type": "object", "additionalProperties": false, "required": [ "domain", "records", "email", "caaIssuers", "certificate", "ctLog", "findings" ], "properties": { "domain": { "type": "string" }, "records": { "type": "object", "additionalProperties": { "type": "array", "items": { "type": "string" } } }, "email": { "type": "object", "additionalProperties": false, "required": [ "spf", "spfLookups", "dmarc", "dmarcPolicy", "mtaSts" ], "properties": { "spf": { "type": [ "string", "null" ] }, "spfLookups": { "type": "integer" }, "dmarc": { "type": [ "string", "null" ] }, "dmarcPolicy": { "type": [ "string", "null" ] }, "mtaSts": { "type": [ "string", "null" ] } } }, "caaIssuers": { "type": "array", "items": { "type": "string" } }, "certificate": { "type": [ "object", "null" ], "additionalProperties": false, "required": [ "subject", "issuer", "validFrom", "validTo", "daysLeft", "san", "keyType", "keyBits", "serialNumber", "fingerprint256", "chainLength", "hostnameMatches", "authorized", "authorizationError", "protocol", "servedFrom" ], "properties": { "subject": { "type": "string" }, "issuer": { "type": "string" }, "validFrom": { "type": "string" }, "validTo": { "type": "string" }, "daysLeft": { "type": "integer" }, "san": { "type": "array", "items": { "type": "string" } }, "keyType": { "type": [ "string", "null" ] }, "keyBits": { "type": [ "integer", "null" ] }, "serialNumber": { "type": "string" }, "fingerprint256": { "type": "string" }, "chainLength": { "type": "integer" }, "hostnameMatches": { "type": "boolean" }, "authorized": { "type": "boolean" }, "authorizationError": { "type": [ "string", "null" ] }, "protocol": { "type": [ "string", "null" ] }, "servedFrom": { "type": "string" } } }, "ctLog": { "type": [ "array", "null" ], "items": { "type": "object", "additionalProperties": false, "required": [ "id", "issuer", "names", "notBefore", "notAfter" ], "properties": { "id": { "type": "integer" }, "issuer": { "type": "string" }, "names": { "type": "array", "items": { "type": "string" } }, "notBefore": { "type": "string" }, "notAfter": { "type": "string" } } } }, "findings": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "severity", "area", "finding" ], "properties": { "severity": { "type": "string", "enum": [ "high", "medium", "low", "info" ] }, "area": { "type": "string" }, "finding": { "type": "string" } } } } } }, "units": { "type": "object", "additionalProperties": { "type": "string" } }, "assumptions": { "type": "array", "items": { "type": "string" } }, "sources": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "title" ], "properties": { "title": { "type": "string" }, "url": { "type": "string" }, "publisher": { "type": "string" }, "retrievedAt": { "type": "string" }, "note": { "type": "string" } } } }, "warnings": { "type": "array", "items": { "type": "string" } }, "presentation": { "type": "array", "items": { "type": "object" }, "description": "Display blocks used by the human page (same data)." }, "links": { "type": "object", "additionalProperties": false, "required": [ "human", "api", "openapi", "methodology" ], "properties": { "human": { "type": "string", "format": "uri" }, "api": { "type": "string", "format": "uri" }, "openapi": { "type": "string", "format": "uri" }, "methodology": { "type": "string", "format": "uri" } } } } } } } }