DechoNet

Check whether a domain is ready to launch or migrate — a go/no-go verdict over five essentials: DNS resolves to an IP, has propagated consistently across global resolvers, SSL/TLS is ready, the site is reachable over HTTPS, and the domain registration is not about to expire. Use this right before flipping DNS to a new server, or to confirm a migration has landed. It answers "can I switch over yet?"; use security_scan for a security posture grade or the individual tools for depth. Any failing essential yields not_ready; only cautions yields caution; all clear yields ready. Read-only (a passive multi-probe, though it does resolve and fetch the domain); requires no API key; rate-limited. Returns the verdict, per-check statuses, and a shareable report link.

golive_check

Follow a URL's HTTP redirect chain and audit response security headers (CSP, HSTS, X-Frame-Options, COOP, CORP, COEP, Permissions-Policy), grading A+ to F on the six core headers (CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy; COOP/CORP/COEP are reported but not graded) and flagging information leaks such as server-version disclosure. Use this for HTTP-layer/header posture. Use ssl_check instead for certificate or TLS-handshake issues, or security_scan for a full domain report. Read-only (an HTTP GET-style probe that sends no payload); requires no API key; rate-limited. Returns a text report: grade, header findings, redirect trace, issues, and actions.

http_security

Compute IPv4 subnet details from CIDR notation entirely locally — no network call: network and broadcast addresses, usable host range, total usable hosts, subnet mask, and wildcard mask. /31 and /32 are handled per RFC 3021 (point-to-point / single host). Use this for IPv4 address planning. It does not query DNS or contact any host, so it is purely computational. Requires no API key and is NOT rate-limited (computed in-process). Returns the calculated fields as text.

subnet_calc

Show how a domain's (or IPv4 address's) infrastructure has changed over time from DechoNet's stored observations: nameservers, A/AAAA, MX, CNAME, certificate issuer, registrar, RDAP nameservers and status, and for an IP its ASN and PTR — each value with when it was first and last seen. Use this when the question is about the past ("when did the nameservers change?", "which IPs has it used?"); use dns_lookup or rdap_lookup for the current state. Coverage: only what DechoNet itself observed (lookups, watches, own discovery, and a daily re-resolution of the Korean-brand and phishing names it tracks) — not full passive DNS. Read-only; requires no API key; rate-limited. Returns per-kind value timelines and a coverage note.

domain_history

Generate the typosquat/lookalike variants of a domain that phishers actually register — homoglyph swaps (l→1, o→0, rn→m), TLD swaps (.com→.co), character omissions, transpositions, repetitions, hyphenations — and check which of them are currently registered (live NS delegation via DoH). Use this to assess brand-impersonation and phishing exposure for a domain the user is responsible for. A registered variant is NOT proof of abuse (it may be an unrelated legitimate site) — follow up with whois_lookup on each hit for its owner and registration date. Read-only; requires no API key; rate-limited. Returns generated/checked counts and the registered variants with the technique that produced each.

lookalike_domains

Assess a domain's OWASP posture from EXTERNAL OBSERVATION only: the OWASP Secure Headers Project plus the externally observable OWASP Top 10:2025 subset — A04 Cryptographic Failures (TLS/cert), A02 Security Misconfiguration (header/info leaks), and A03 Software Supply Chain Failures (outdated components via version disclosure) — returning an A+ to F grade. Scope: A01 (Access Control, incl. SSRF), A05 (Injection), A06 (Insecure Design), A07 (Authentication), A08, A09 and A10 (Exceptional Conditions) are not checked — they need authenticated access or active/injection testing, so the result lists them as out-of-scope rather than "pass". The result is an external-posture check, not a full OWASP Top 10 assessment. Unlike security_scan this is PASSIVE (a normal HTTPS request, the TLS certificate and a public CT-log lookup; no port scan, no path probing), so it is suitable for domains you do not own. The sensitive-file check (.env, .git, server-status) runs only for the verified domain owner on the web report (DNS TXT), never through this tool. Use http_security or ssl_check for depth on one layer. Read-only; requires no API key; rate-limited. Returns a text report: grade, per-category findings, the out-of-scope list, and a shareable report link.

owasp_check

Probe a host for a fixed set of common TCP ports (HTTP, HTTPS, SSH, FTP, SMTP, DNS, and common databases) and report which are open, the service name, and the response time. BEHAVIOR: this makes an ACTIVE TCP connection to the target. It is non-intrusive — a connect probe only; it does not authenticate, send exploits, or transfer data — and changes nothing on the target (read-only), but the connection is visible in the target's logs, so only scan hosts you own or are explicitly authorized to test. Use this to confirm which services are exposed. Use ssl_check or http_security instead to assess a specific service's configuration. Requires no API key; rate-limited. Returns a per-port open/closed list with service names.

port_scan

Check the links in a suspicious text message (smishing) or e-mail before anyone taps them. Paste the whole message or a single URL: every link is extracted, followed through URL shorteners to its real destination, and judged on observable signals — domain age from RDAP, impersonation of Korean banks/couriers/telecoms/portals and global brands incl. AI services such as ChatGPT/Claude/Gemini (brand keyword, lookalike spelling, or the brand domain worn as a subdomain), ClickFix pages (a fake "verify you are human" check that has the visitor paste a command into Win+R/PowerShell), Android APK downloads, punycode, public phishing/malware feeds, and DechoNet's own impersonation tracking. Use this when a user asks whether a link or message is a scam. Verdicts: danger, suspicious, unreachable, official (lands on the brand's own domain), no_signals (no warning signs found; this is not a finding that the link is safe). Reads landing-page HTML; inconclusive links may also run page scripts in isolated Chromium under the shared daily cap. DechoNet does not click, enter values or submit forms. The message text is not stored; requires no API key; rate-limited. Returns per-link verdicts with reasons and a shareable report link.

phishing_link_check

Check whether a website's public TLS endpoint is ready for post-quantum cryptography: does it complete a TLS 1.3 handshake that offers only the hybrid X25519MLKEM768 key exchange (ML-KEM), and does the organisation's own server provide it or a CDN edge in front of it. Also reports what the certificate chain is signed with (tracked, not scored: public CAs do not issue post-quantum certificates yet). Verdicts: ready (the origin server supports it), partial (a CDN edge provides it; the CDN-to-origin leg is invisible), not_ready (the hybrid-only handshake was refused), unknown (inconclusive — not the same as "no"). Scope: only the public endpoint on port 443. Internal systems, VPNs, code, and Korean PQC algorithms (no standard TLS codepoints yet) are not observable, so the result is an external indicator of migration progress, not a full PQC audit. Read-only; requires no API key; rate-limited. Returns the verdict, a 0-100 readiness score and grade, per-check statuses, and a shareable report link.

pqc_readiness

Report a page to DechoNet: phishing or brand impersonation, a fake payment window (card fields where a payment provider should be), hidden instructions aimed at AI agents, a malicious download, a DechoNet verdict that looks wrong (false_positive) or a danger it missed (missed), an MCP server whose tool descriptions steer agents (malicious_mcp — url is the MCP endpoint), or a network anomaly (network_anomaly — the certificate serial/issuer or addresses you saw for the host, in observed). Kept for 90 days: the host and the kind, with an anonymous reporter hash used to count independent reports; for malicious_mcp the endpoint path, for network_anomaly the observed values and the country of the connection. No query, page text or free text. A report changes no verdict by itself: DechoNet opens the page itself and only what it observes counts; pages reported by several independent sources are looked at first. Not read-only (it records the report); rate-limited.

report_page

Resolve the PTR (reverse DNS) record for an IPv4 or IPv6 address and verify forward-confirmed reverse DNS (FCrDNS) by checking that the PTR hostname resolves back to the same IP. Infers the hosting provider from PTR naming patterns. Use this to validate mail-server rDNS or identify a single IP's host. Use asn_lookup instead for network/BGP ownership of the IP. Read-only; requires no API key; rate-limited. Returns the PTR hostname, FCrDNS pass/fail, and a provider guess.

reverse_dns

Inspect a host's served TLS/SSL certificate and connection: expiry date, issuer, SAN list, chain integrity, revocation (OCSP, then CRL; unknown when neither answers — not graded unless revoked), TLS version, and HSTS, returning an A+ to F grade weighted by certificate validity (40%), TLS version (25%), chain trust (15%), and HSTS (20%). Use this to diagnose certificate or HTTPS-handshake problems for one host. Use http_security instead to audit response security headers, or security_scan for an all-in-one domain report. Read-only: it completes a TLS handshake but sends no application data; requires no API key; rate-limited. Returns a text report: grade, expiry/issuer KPIs, issues, and actions.

ssl_check

Record what a domain should show from outside and check it now — HSTS or another header present, DMARC enforcing, an issue key no longer reported, an HTTP or TLS grade at or above a level, a certificate with enough days left, a DNS record present, absent or containing a value, HTTPS answering. DechoNet reads the domain fresh (not from cache) with its public dns / ssl / http / email tools, from its own servers and the Seoul observation point, and then re-checks the set every day. Each result is pass, fail or unknown; unknown (a tool or part of it did not answer) is never a pass. Without an API key the set is anonymous: no alerts, kept 30 days after its last check, reachable by id and status page. With an API key (Authorization: Bearer dn_…) the set belongs to that key's account, and a set that held and stops holding is reported in the account's daily mail. Not read-only (it stores the set); public checks only, so any domain is accepted. Typical use: after changing DNS, TLS, headers or mail settings, to state the intended result and be told if it is ever reverted. Returns the set id, status page, per-check results with where to fix what does not hold (for the platform the site runs on), and signed observation receipts.

set_expectations

Enumerate the subdomains of a domain from Certificate Transparency logs — fully passive (no packets are sent to the target; CT logs are public records of every TLS certificate ever issued). Flags operational-looking names (dev, staging, admin, vpn, legacy) and wildcard certificates, because forgotten subdomains are a common takeover path. Use this as the first recon step to map a domain's attack surface. Use dns_lookup to check whether a discovered name still resolves, or lookalike_domains for typosquat variants of the domain name itself. Read-only; requires no API key; rate-limited. Returns the subdomain count, risky-name count, wildcard flag, and the hostname list.

subdomain_discovery

Check expectations from outside now, with fresh reads: either a stored set by id (from set_expectations — its state is updated and an anonymous set is kept another 30 days), or a domain plus a list of checks once, storing nothing. Same checks and outcomes as set_expectations (pass / fail / unknown, unknown is never a pass), each tool read once with a signed observation receipt. Typical use: right after a change, to see whether it is visible from outside yet — DNS and CDN changes can take minutes to hours to show. Rate-limited (a few checks per minute).

verify_expectations

Retrieve domain registration data via RDAP (with WHOIS fallback): registrar, creation/expiry/update dates, nameservers, and EPP status flags, highlighting risk states such as clientHold and pendingDelete. Use this for ownership, lifecycle, and expiry questions about a registered domain. Use dns_lookup instead for live DNS records, or reverse_dns/asn_lookup for IP-level ownership. Read-only; requires no API key; rate-limited. Returns registrar, key dates, nameservers, and status flags.

whois_lookup

Start (or reuse) a daily DechoNet watch on a domain so that changes are recorded over time — SSL grade/issuer/expiry, DNS records, HTTP security headers, domain registration, and optionally OWASP posture and impersonation exposure. Use this once when the user cares about a domain beyond a one-off check (their own domain, a client, a vendor, a target under investigation). After this, domain_changes answers "what changed since last time?" from real daily snapshots. Not read-only (it creates a watch record) but idempotent: watching an already-watched domain returns the existing watch. No account, no email, no PII — a watch is keyed by domain+tool and its history page is a public unguessable URL you can share with the user. Rate-limited (a few watches per minute).

watch_domain