DNS Doctor

Use this when the user asks who can send email as their domain through SPF includes, or wants an SPF supply-chain or third-party sender audit. Audit a domain's SPF supply chain: walks every include and redirect it delegates to, and reports who can transitively send as it. Returns the resolved tree, per-node lookup attribution, the total authorized IPv4 address count, and typed findings — include_broken (a target that no longer publishes SPF, a PermError today), include_registrable (a delegated-to domain that does not exist, so a stranger who registers it becomes an authorized sender), include_expiring (registration lapsing within 30 days), pass_all_nested (a +all deep in the chain) and spf_record_unusable (the audited domain's OWN record is missing or does not parse, so there is no chain to walk). A domain we could not verify is reported as unverified and NEVER as available — never tell anyone a name is free on this tool's say-so unless the finding is include_registrable AND carries registry_confirmed: true. A registry_confirmed: false finding rests on DNS alone, which cannot tell an unsold name from one in redemption or on clientHold: report the mechanism as broken and the takeover risk as possible, but never as an available domain. Findings are risk analysis, not instructions: no SPF fix record exists here or anywhere else in DNS Doctor, because dropping a mechanism can silently de-authorize a real sender — relay the findings and let the domain's owner decide. Use count_spf_lookups instead when the question is only the 10-lookup limit.

Use this when the user asks how to move DMARC on from p=none, whether it is safe to tighten DMARC, or what the next DMARC policy step is for a domain (a scan can justify quarantine at most; reject needs monitoring evidence). Return a validated DMARC enforcement-upgrade record for a domain. A scan can justify p=quarantine at MOST: the alignment signal (valid aligned SPF and a DKIM selector) is derived server-side — a caller can never assert it — and p=reject is unlocked only by aggregate-report evidence over a full reporting window (monitoring), never by a scan. `record` is null when there is no honest upgrade to offer (the domain does not exist; the DMARC lookup itself hit NXDOMAIN while the existence probe did not resolve; the DMARC lookup temp-failed; no alignment signal was observed at all, so a non-enforcing domain is told to publish rua= reporting first and an enforcing one is left alone; or the domain already applies a policy at least as strong as this scan justifies): a null record is the ANSWER, not a fault — relay `rationale` and never compose a record to fill the gap. A returned record also carries np=reject (the DMARCbis tag covering non-existent subdomains, which can have no legitimate aligned mail) unless the domain already publishes an np tag, which is preserved as-is. Present a returned record verbatim; a human must approve before publishing.

Use this when the user asks whether DKIM is set up for a sending platform, whether a specific selector exists, or why DKIM fails. Check ONE specific DKIM selector on a domain — the exact selector the sending platform uses (e.g. `google`, `s1`), which a full scan's common-selector sweep may miss. Returns the verdict, its explanation, and the published key record when one resolves. No fix record is returned: a DKIM key is generated by the sending platform, so the fix is always to publish what that platform gives the owner.

Use this when the user asks whether a DNS change has propagated globally, or why a record shows in one place and not another. Check whether a DNS change has propagated GLOBALLY: six vantage points (five owner-run probes across four continents plus this server's own resolver) each read the same name through several resolvers, and the grid plus a deterministic verdict comes back. Call it after the human publishes a record — you have ONE network vantage point, and a record that resolves for you can still be missing elsewhere. `name` is the exact name (www. is not stripped, _dmarc.example.com works), `record_type` is A|AAAA|CNAME|MX|TXT|NS, and the optional `expected_value` turns each cell into match or mismatch instead of agreement-only. Observation only: no record is ever composed here. A cell that did not answer is `unavailable`, which is NOT a negative result, and when fewer than three vantage points were reached the verdict downgrades to `unknown` — report vantage_reached of vantage_total rather than calling a name converged on partial coverage.

Use this when the user asks whether a DNS change has landed, wants a DNS record looked up, or wants to verify a record they just published. Check whether a DNS change has landed: reads the record from the domain's OWN nameservers (cache-free) and from two public caching resolvers, and reports whether they agree. `kind` is one of spf|dmarc|txt|mx|cname|a|aaaa — pass the kind, not a query name: `dmarc` reads TXT at _dmarc.<domain> and `spf` reads apex TXT, each filtered to the matching record. `host` prepends a label (txt, cname, a and aaaa only). Empty values mean the record is genuinely absent. When in_sync is false, max_wait_seconds is the largest remaining cached TTL — the wait before those resolvers refresh. This samples two resolvers, so never describe it as worldwide or as propagation coverage.

Use this when the user asks about reverse DNS, PTR records, or FCrDNS for a mail server IP. Check one sending IP's forward-confirmed reverse DNS (FCrDNS): reads the IP's PTR record, then resolves that hostname back and reports whether it returns to the same IP. `verdict` is confirmed (the pair agrees — what receivers want to see), ptr_missing (the IP publishes no reverse record), or mismatch (a PTR that does not resolve back). A PTR on its own proves nothing, because the IP's operator writes its own reverse zone — only the forward confirmation is evidence, so never report a bare PTR as verified. The fix is always made by whoever controls the IP (the hosting or mail provider), never in the sending domain's own DNS. Pass a public IPv4 or IPv6 address.

Use this when the user asks about SPF 'too many lookups', the 10-lookup limit, an SPF PermError, or whether an SPF record is valid. Validate an SPF record and count what it costs. Returns `record_valid` (the record parses as RFC 7208 SPF), `findings` (per-term diagnostics), `has_pass_all` (a `+all` that authorizes the whole internet to send as this domain), `multiple_all` (more than one `all`, which makes everything after the first unreachable), the parsed `terms`, and the lookup count against the limit of 10 with `over_limit`/`near_limit` and the `offending_mechanisms` that push it over. Pass EXACTLY ONE of `domain` (resolves the published record and counts recursively through nested includes) or `record` (parses a pasted record, its own terms only). This is the SPF validator — there is no separate one. Diagnose-only: no SPF fix record is ever returned, because removing a mechanism can silently de-authorize a real sender — relay the findings and let the domain's owner decide what to drop.

Build a DMARC record from scratch for a domain that has none, using a validating engine — never compose one yourself. `policy` is none|quarantine|reject; optional `rua_email` (aggregate-report destination), `subdomain_policy`, and `strict_alignment`. The generated record is re-validated before it is returned. Present it verbatim; a human must approve before publishing.

Use this when a signed-in operator asks what changed on a monitored domain, or what the monitoring has flagged. Read the monitoring alert log for the domains the caller's account monitors, newest first. Requires an API token. Each row carries id, domain, type, check, summary, a deterministic detail map, created_at, email_sent_at, acknowledged_at and delivery_class — a 'dashboard_only' row was deliberately kept out of the digest mail, so an agent watching only the inbox would never see it; this log is the complete picture. PAGE DOWN BEFORE ADVANCING `since`: next_before is non-null exactly when older rows remain, and a caller that ignores it, takes a full page and moves its watermark to the newest row it saw drops every row it did not receive. `since` is an INCLUSIVE floor, so rows repeat rather than go missing — de-duplicate on id. READ-ONLY by decision: there is no ack and no delete here, because acknowledging an alert is the human's own triage on their dashboard and an agent that acks on their behalf silences a row they have never seen. Report what the log says and let them clear it.

Use this when a signed-in operator asks whether a monitored domain is ready for the next DMARC step. Read the DMARC enforcement-readiness verdict for ONE domain the caller's account monitors, computed from its aggregate (RUA) report window. Requires an API token. Returns whether the domain is ready to step its policy up, the blockers that say why it is not, the window the verdict rests on, and next_record — the validated record for the next step, generated by the engine and null while blocked. THAT NULL IS AN ANSWER: relay the blockers and never compose a stronger record to fill the gap. Present a returned record verbatim; a human must approve it before it is published. Use this before proposing enforcement — a scan can show a domain's current policy, but only this evidence window can say whether tightening it would start rejecting real mail.