{
  "markdown": "# Deliverability Doctor\nRemote MCP server: **\"Can my domain be email-spoofed?\"** answered from public DNS,\ngraded, with concrete fixes. Connectable to Claude (custom connector) and ChatGPT\n(Apps SDK / MCP connector) — both speak MCP, one server serves both.\n\n## Tools\n- `check_email_security(domain)` — SPF (incl. RFC 7208 multiple-record permerror\n  and `redirect=` handling), DMARC (policy, rua, pct), MX, DKIM at 7 common\n  selectors. Graded A–F report, fixes per finding, upsell line only when problems\n  exist. Accepts bare domain, URL, or email address.\n- `compare_email_security(domains[2..5])` — comparison table with grades.\n\n## Design decisions\n- **Authless**: reads public DNS only, stores nothing, takes nothing but a domain.\n  Lowest possible connect friction; nothing sensitive to protect.\n- **DNS-over-HTTPS** (Cloudflare → Google fallback): identical code runs on local\n  Node and on Cloudflare Workers — no `dns` module dependency.\n- **Stateless streamable HTTP**: fresh transport per request, no sessions; safe to\n  scale, trivial for clients.\n- **NXDOMAIN is refused, not graded** — \"domain doesn't exist\" ≠ \"spoofable\".\n- Verified against known postures before first run: gmail.com (`redirect=` must\n  not be flagged), n8n.io (must grade A on `p=reject`), missing-everything domain\n  (must grade F), NXDOMAIN (must refuse).\n\n## Run\n```bash\nnpm install\nnode server.js          # :8787/mcp\n```\nQuick public demo: `cloudflared tunnel --url http://localhost:8787` → use\n`https://<random>.trycloudflare.com/mcp` as the connector URL.\n\n## Status 2026-08-23\n- Local: end-to-end MCP verified (initialize / tools/list / tools/call).\n- Public: live via quick tunnel, initialize verified from the public URL.\n- Durable hosting: **pending** — Cloudflare Workers deploy needs Kacper's account\n  (~5 min). Tunnel URL dies with the process/PC.\n- Directory submissions (Anthropic connector directory, ChatGPT apps): need the\n  durable URL first, then Kacper's developer accounts.\n\n## Monetization path\nFree tool = distribution. Report links the $99 written audit\n(niekonieczny.gumroad.com/l/vscjt) only when problems are found.\nNOTE: Gumroad payouts currently frozen on Stripe KYC — unfreeze before promoting.\n",
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  "repo_slug": "integrity-os/deliverability-doctor",
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  "api": "https://agentalog.com/api/listings/mcp_io_github_integrity_os_deliverability_do_94f5603a/readme"
}