# dnsdoctor 🩺

**Will email from a domain reach the inbox — or the spam folder?** dnsdoctor does a live **SPF / DKIM / DMARC / MX** check for any domain and returns a `HEALTHY` / `NEEDS_ATTENTION` / `AT_RISK` verdict with the **exact DNS records to add or fix**.

It is both an **MCP server** (for Claude, Cursor and other AI agents) and a **pay-per-call x402 HTTP API**.

Why it exists: an AI agent setting up email, debugging "my mail goes to spam", or vetting a domain **cannot resolve live DNS by itself**. dnsdoctor does, and turns it into an actionable answer — including the Gmail/Yahoo 2024 bulk-sender requirements (DMARC).

## MCP server (free)

```json
{
  "mcpServers": {
    "dnsdoctor": { "command": "npx", "args": ["-y", "dnsdoctor-mcp"] }
  }
}
```

Tool: `check_email_deliverability(domain, deep?)`.

## Free HTTP API

```
GET https://dnsdoctor.vercel.app/check?domain=github.com
```

Returns SPF/DMARC/MX status, a deliverability score and concrete fixes. Rate-limited to 30/hour/IP.

## Pay-per-call (x402)

```
GET https://dnsdoctor.vercel.app/pro/check?domain=<domain>
```

Gated by [x402](https://x402.org): your agent pays **$0.02 USDC** (on Base) per call automatically — no sign-up, no API key. The deep tier also probes common **DKIM** selectors. The server holds no private key; payment settles on-chain to the operator wallet.

## What it checks

| Check | What & why |
|---|---|
| **SPF** | present? ends in `-all`/`~all`? dangerous `+all` that lets anyone spoof you |
| **DMARC** | present? policy `p=none/quarantine/reject` — the Gmail/Yahoo 2024 bulk-sender requirement |
| **DKIM** | probes common selectors for a published signing key (deep mode) |
| **MX** | can the domain receive mail at all, and where |

## Develop

```
npm install
npm run dev:http     # local HTTP API on :8080
npm test             # live engine tests
```

MIT.