{
    "ok": true,
    "domain": "stepik.org",
    "generated_at": "2026-08-10T10:31:02-05:00",
    "cache": {
        "hit": true,
        "ttl": 0
    },
    "score": {
        "total": 75,
        "label": "Good",
        "categories": {
            "dns": 70,
            "mail": 90,
            "security": 69,
            "network": 20,
            "availability": 100
        },
        "category_weights": {
            "dns": 25,
            "mail": 20,
            "security": 25,
            "network": 10,
            "availability": 20
        },
        "items": [
            {
                "category": "dns",
                "title": "IPv4 (A)",
                "max_points": 30,
                "earned_points": 30,
                "lost_points": 0,
                "detail": "1 IPv4 address(es) detected."
            },
            {
                "category": "dns",
                "title": "IPv6 (AAAA)",
                "max_points": 10,
                "earned_points": 0,
                "lost_points": 10,
                "detail": "0 IPv6 address(es) detected."
            },
            {
                "category": "dns",
                "title": "Name server redundancy",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0,
                "detail": "2 NS record(s); 2 or more required."
            },
            {
                "category": "dns",
                "title": "SOA record",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0,
                "detail": "Authoritative zone record."
            },
            {
                "category": "dns",
                "title": "DNSSEC chain",
                "max_points": 15,
                "earned_points": 0,
                "lost_points": 15,
                "detail": "Both DS and DNSKEY are required."
            },
            {
                "category": "dns",
                "title": "CAA policy",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5,
                "detail": "Certificate authority restriction."
            },
            {
                "category": "dns",
                "title": "DNS propagation",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0,
                "detail": "Agreement between public resolvers."
            },
            {
                "category": "mail",
                "title": "MX records",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0,
                "detail": "1 MX record(s)."
            },
            {
                "category": "mail",
                "title": "SPF",
                "max_points": 25,
                "earned_points": 25,
                "lost_points": 0,
                "detail": "SPF policy published."
            },
            {
                "category": "mail",
                "title": "DMARC",
                "max_points": 25,
                "earned_points": 25,
                "lost_points": 0,
                "detail": "DMARC policy published."
            },
            {
                "category": "mail",
                "title": "DKIM",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0,
                "detail": "A DKIM selector was verified."
            },
            {
                "category": "mail",
                "title": "MTA-STS",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5,
                "detail": "Mail transport policy."
            },
            {
                "category": "mail",
                "title": "TLS-RPT",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5,
                "detail": "TLS reporting policy."
            },
            {
                "category": "security",
                "title": "Valid TLS certificate",
                "max_points": 55,
                "earned_points": 55,
                "lost_points": 0,
                "detail": "73 day(s) remaining."
            },
            {
                "category": "security",
                "title": "Certificate lifetime",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0,
                "detail": "Full points require at least 30 days remaining."
            },
            {
                "category": "security",
                "title": "HTTP security headers",
                "max_points": 35,
                "earned_points": 4,
                "lost_points": 31,
                "detail": "1 of 9 evaluated headers detected."
            },
            {
                "category": "network",
                "title": "PTR reverse DNS",
                "max_points": 30,
                "earned_points": 0,
                "lost_points": 30,
                "detail": "PTR not detected."
            },
            {
                "category": "network",
                "title": "IPv4 diversity",
                "max_points": 35,
                "earned_points": 20,
                "lost_points": 15,
                "detail": "Two or more IPv4 addresses receive full points."
            },
            {
                "category": "network",
                "title": "IPv6 connectivity",
                "max_points": 35,
                "earned_points": 0,
                "lost_points": 35,
                "detail": "AAAA availability."
            },
            {
                "category": "availability",
                "title": "DNS resolution",
                "max_points": 40,
                "earned_points": 40,
                "lost_points": 0,
                "detail": "At least one address family must resolve."
            },
            {
                "category": "availability",
                "title": "HTTP response",
                "max_points": 40,
                "earned_points": 40,
                "lost_points": 0,
                "detail": "HTTP/2 200 "
            },
            {
                "category": "availability",
                "title": "HTTPS final URL",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0,
                "detail": "Final URL uses HTTPS."
            }
        ],
        "methodology": "Each category is normalized to 100. The total is the weighted sum: DNS 25%, Email 20%, Security 25%, Network 10%, Availability 20%.",
        "diagnostics": [
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                "level": "ok",
                "title": "IPv4 (A)",
                "detail": "1 IPv4 address(es) detected.",
                "category": "dns",
                "max_points": 30,
                "earned_points": 30,
                "lost_points": 0
            },
            {
                "level": "error",
                "title": "IPv6 (AAAA)",
                "detail": "0 IPv6 address(es) detected.",
                "category": "dns",
                "max_points": 10,
                "earned_points": 0,
                "lost_points": 10
            },
            {
                "level": "ok",
                "title": "Name server redundancy",
                "detail": "2 NS record(s); 2 or more required.",
                "category": "dns",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "SOA record",
                "detail": "Authoritative zone record.",
                "category": "dns",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0
            },
            {
                "level": "error",
                "title": "DNSSEC chain",
                "detail": "Both DS and DNSKEY are required.",
                "category": "dns",
                "max_points": 15,
                "earned_points": 0,
                "lost_points": 15
            },
            {
                "level": "error",
                "title": "CAA policy",
                "detail": "Certificate authority restriction.",
                "category": "dns",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5
            },
            {
                "level": "ok",
                "title": "DNS propagation",
                "detail": "Agreement between public resolvers.",
                "category": "dns",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "MX records",
                "detail": "1 MX record(s).",
                "category": "mail",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "SPF",
                "detail": "SPF policy published.",
                "category": "mail",
                "max_points": 25,
                "earned_points": 25,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "DMARC",
                "detail": "DMARC policy published.",
                "category": "mail",
                "max_points": 25,
                "earned_points": 25,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "DKIM",
                "detail": "A DKIM selector was verified.",
                "category": "mail",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0
            },
            {
                "level": "error",
                "title": "MTA-STS",
                "detail": "Mail transport policy.",
                "category": "mail",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5
            },
            {
                "level": "error",
                "title": "TLS-RPT",
                "detail": "TLS reporting policy.",
                "category": "mail",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5
            },
            {
                "level": "ok",
                "title": "Valid TLS certificate",
                "detail": "73 day(s) remaining.",
                "category": "security",
                "max_points": 55,
                "earned_points": 55,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "Certificate lifetime",
                "detail": "Full points require at least 30 days remaining.",
                "category": "security",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0
            },
            {
                "level": "warning",
                "title": "HTTP security headers",
                "detail": "1 of 9 evaluated headers detected.",
                "category": "security",
                "max_points": 35,
                "earned_points": 4,
                "lost_points": 31
            },
            {
                "level": "error",
                "title": "PTR reverse DNS",
                "detail": "PTR not detected.",
                "category": "network",
                "max_points": 30,
                "earned_points": 0,
                "lost_points": 30
            },
            {
                "level": "warning",
                "title": "IPv4 diversity",
                "detail": "Two or more IPv4 addresses receive full points.",
                "category": "network",
                "max_points": 35,
                "earned_points": 20,
                "lost_points": 15
            },
            {
                "level": "error",
                "title": "IPv6 connectivity",
                "detail": "AAAA availability.",
                "category": "network",
                "max_points": 35,
                "earned_points": 0,
                "lost_points": 35
            },
            {
                "level": "ok",
                "title": "DNS resolution",
                "detail": "At least one address family must resolve.",
                "category": "availability",
                "max_points": 40,
                "earned_points": 40,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "HTTP response",
                "detail": "HTTP/2 200 ",
                "category": "availability",
                "max_points": 40,
                "earned_points": 40,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "HTTPS final URL",
                "detail": "Final URL uses HTTPS.",
                "category": "availability",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0
            }
        ]
    },
    "dns": {
        "records": {
            "A": [
                "178.248.239.111"
            ],
            "AAAA": [],
            "CNAME": [],
            "MX": [
                "10 mx.yandex.net."
            ],
            "TXT": [
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                "\"yandex-verification: fa6a64e3034dc7b7\"",
                "\"yandex-verification: a4dbed4d96915f29\"",
                "\"v=spf1 mx ip4:40.113.130.203 ip4:51.250.53.246 ip4:40.119.132.203 ip4:104.47.158.169 include:mail.zendesk.com include:servers.mcsv.net include:_spf.google.com include:_spf.myjetbrains.com include:_spf.yandex.net ~all\"",
                "\"MS=ms61610138\""
            ],
            "NS": [
                "ns78.domaincontrol.com.",
                "ns77.domaincontrol.com."
            ],
            "SOA": [
                "ns77.domaincontrol.com. dns.jomax.net. 2024101601 28800 7200 604800 600"
            ],
            "CAA": [],
            "DS": [],
            "DNSKEY": [],
            "RRSIG": [],
            "NSEC": [],
            "NSEC3": [],
            "SRV": [],
            "NAPTR": [],
            "TLSA": [],
            "SSHFP": []
        },
        "ipv4": [
            "178.248.239.111"
        ],
        "ipv6": []
    },
    "mail": {
        "spf": "v=spf1 mx ip4:40.113.130.203 ip4:51.250.53.246 ip4:40.119.132.203 ip4:104.47.158.169 include:mail.zendesk.com include:servers.mcsv.net include:_spf.google.com include:_spf.myjetbrains.com include:_spf.yandex.net ~all",
        "dmarc": "v=DMARC1;p=none;rua=mailto:dmarc@stepik.org",
        "dkim_selector": "google",
        "dkim_host": "google._domainkey.stepik.org",
        "dkim": "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAj/hoU9mOph+So8dUo/MrSmPh3qxieqs1D1IHCXFhOtbdOPxhkOn5gp0ReuCJh2DFiWB7gymp9SFXf0/jVnGNjyQ2QD4Rz+lN84NW3pokFce+CrPkmBSXM2ISfGqKEWL3+AAqd5E5OrlE0jeDK5dnUvgxOK2yUQ+QMuvVQHs0SYTL3EgP+ZRVrXjVKYoQoa1Ml01xyJTr26fawfbo39lBeIxQcHeBL0peNUStooRbD2f6eAuW/ZZgnu1Juxouqw2FswDfm7heo/znmVZJNTYg8o6x6U0naJS04FkeBNXYHw8u8t+Ilhb5aVVQZyZWfusvlp8YTaZ08gIhMcXyitYv6wIDAQAB",
        "spf_analysis": {
            "valid": true,
            "lookups": 6,
            "final": "~all",
            "message": "Within the estimated limit"
        },
        "dmarc_analysis": {
            "valid": true,
            "policy": "none"
        },
        "bimi": "",
        "mta_sts": "",
        "tls_rpt": ""
    },
    "advanced": {
        "ptr": "",
        "propagation": {
            "consistent": true,
            "results": [
                {
                    "provider": "Google",
                    "server": "8.8.8.8",
                    "result": [
                        "178.248.239.111"
                    ],
                    "time_ms": 111.74
                },
                {
                    "provider": "Cloudflare",
                    "server": "1.1.1.1",
                    "result": [
                        "178.248.239.111"
                    ],
                    "time_ms": 84.26
                },
                {
                    "provider": "Quad9",
                    "server": "9.9.9.9",
                    "result": [
                        "178.248.239.111"
                    ],
                    "time_ms": 89.32
                },
                {
                    "provider": "OpenDNS",
                    "server": "208.67.222.222",
                    "result": [
                        "178.248.239.111"
                    ],
                    "time_ms": 90.5
                },
                {
                    "provider": "AdGuard",
                    "server": "94.140.14.14",
                    "result": [
                        "178.248.239.111"
                    ],
                    "time_ms": 281.26
                }
            ]
        }
    },
    "ssl": {
        "available": true,
        "issuer": "Let's Encrypt",
        "subject": "stepik.org",
        "valid_from": "2026-07-24T16:03:56-05:00",
        "valid_to": "2026-10-22T16:03:55-05:00",
        "days_remaining": 73,
        "san": [
            "stepic.org",
            "stepik.org",
            "www.stepic.org",
            "www.stepik.org"
        ],
        "protocol": "TLSv1.3",
        "cipher": "TLS_AES_128_GCM_SHA256"
    },
    "http": {
        "url": "https://stepik.org/",
        "status": "HTTP/2 200 ",
        "http_version": "3",
        "headers": {
            "server": "QRATOR",
            "date": "Mon, 10 Aug 2026 15:30:53 GMT",
            "content-type": "text/html; charset=utf-8",
            "content-length": "48993",
            "strict-transport-security": "max-age=31536000; includeSubDomains",
            "set-cookie": "sessionid=cbh1sz0d3wcy0ltkpdvtldivj7114o7n; expires=Sun, 08-Nov-2026 15:30:53 GMT; HttpOnly; Max-Age=7776000; Path=/; SameSite=None; Secure",
            "vary": "Cookie, Authorization"
        },
        "security_checks": {
            "strict-transport-security": true,
            "content-security-policy": false,
            "x-content-type-options": false,
            "x-frame-options": false,
            "referrer-policy": false,
            "permissions-policy": false,
            "cross-origin-opener-policy": false,
            "cross-origin-embedder-policy": false,
            "cross-origin-resource-policy": false
        },
        "server": "QRATOR",
        "powered_by": ""
    },
    "webpage": {
        "url": "https://stepik.org/",
        "title": "Онлайн-курсы - Stepik",
        "description": "Образовательная платформа - Stepik Выберите подходящий вам онлайн-курс из более чем 20 тыс. и начните получать востребованные навыки.",
        "success": true,
        "error": "",
        "status": 200
    },
    "network": {
        "178.248.239.111": {
            "success": false,
            "country": "",
            "region": "",
            "city": "",
            "asn": "",
            "organization": "",
            "isp": ""
        }
    },
    "smtp": {
        "host": "mx.yandex.net",
        "ports": [
            {
                "port": 25,
                "open": false,
                "time_ms": 106.6,
                "banner": "",
                "error": "Network is unreachable"
            },
            {
                "port": 465,
                "open": false,
                "time_ms": 4126.2,
                "banner": "",
                "error": "Connection timed out"
            },
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                "port": 587,
                "open": false,
                "time_ms": 4021.1,
                "banner": "",
                "error": "Connection timed out"
            }
        ]
    },
    "visitor": {
        "ip": "216.73.217.62",
        "reverse": "",
        "country": "",
        "country_code": "",
        "region": "",
        "city": "",
        "latitude": null,
        "longitude": null,
        "isp": "",
        "organization": "",
        "asn": "",
        "timezone": "",
        "browser": "Other",
        "os": "Other",
        "language": "",
        "user_agent": "Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)",
        "is_bot": true,
        "cloudflare": false
    },
    "analysis_time_ms": 107.08
}