domainlooker

A fast command-line suite and MCP server for inspecting domains — WHOIS, DNS, SSL, open ports, and subdomains — with CSV and JSON export.

Every lookup runs in parallel, WHOIS uses RDAP (HTTP/JSON) first with a port-43 fallback, and timeouts are tight, so a full report typically lands in ~1–2 seconds.

Documentation · npm · GitHub

Install

npm install -g domainlooker

Usage

Run a full report on a domain:

domainlooker example.com

Or use a single-aspect subcommand when you only need one thing:

domainlooker whois example.com
domainlooker dns example.com
domainlooker ssl example.com
domainlooker ports example.com
domainlooker subdomains example.com

Commands

| Command | Description | | --- | --- | | inspect <domains...> | Full report: WHOIS, DNS, SSL, ports, and advisories (this is the default, so domainlooker <domain> runs it) | | whois <domain> | Registration data | | dns <domain> | DNS records (A, AAAA, MX, NS, TXT, SOA) | | ssl <domain> | SSL certificate details and expiry | | ports <domain> | Scan common ports and identify services | | subdomains <domain> | Discover subdomains via certificate transparency and common-name checks | | propagation <domain> | Check DNS propagation across ~25 public resolvers worldwide (--type, --map) | | mcp | Run as an MCP server over stdio (see below) |

inspect options

-q, --quick              Skip the port scan
--subdomains             Also discover subdomains
-p, --parallel <number>  Domains to process in parallel (default: 3)
--export-csv <file>      Write results to a CSV file
--export-json <file>     Write results to a JSON file
-v, --verbose            Show underlying errors

Examples

# Inspect several domains at once
domainlooker google.com github.com microsoft.com

# Quick scan plus subdomain discovery
domainlooker example.com --quick --subdomains

# Export to CSV and JSON
domainlooker example.com --export-csv report.csv --export-json report.json

DNS propagation

domainlooker propagation <domain> queries a worldwide spread of ~25 public resolvers — regional ISP resolvers on every inhabited continent plus the global anycast providers — and reports which are already in sync with the majority answer. Useful after changing a record, or to spot GeoDNS differences.

domainlooker propagation example.com                 # table of resolver answers + % in sync
domainlooker propagation example.com --type AAAA     # any of A, AAAA, CNAME, MX, NS, TXT
domainlooker propagation example.com --map world.html  # + an interactive world-map report

--map writes a self-contained HTML page: a world map with each resolver plotted at its location, crosses flipping to ticks as regions come into sync, alongside a per-resolver list. Open it in a browser.

MCP server

domainlooker mcp runs an MCP server over stdio so AI agents can pull domain intelligence directly. inspect_domain results are cached for a few minutes, so repeat calls return instantly. Every tool refuses IP literals and hosts that resolve to private/loopback/link-local addresses, so an agent can't turn the server into an internal-network scanner.

Register it with any MCP client. For example:

{
  "mcpServers": {
    "domainlooker": {
      "command": "domainlooker",
      "args": ["mcp"]
    }
  }
}

Tools exposed:

| Tool | Description | | --- | --- | | inspect_domain | Full intelligence for a domain (WHOIS, DNS, SSL, ports, advisories) as one structured object. Args: domain, includePorts (default true), includeSubdomains (default false). | | whois_lookup | Registration data (RDAP with WHOIS fallback). | | dns_records | A, AAAA, MX, NS, TXT, SOA records. | | ssl_certificate | TLS certificate details and days until expiry. | | scan_ports | Open TCP ports and identified services. | | find_subdomains | Subdomains via certificate transparency and common names. | | dns_propagation | Per-resolver answers worldwide + an in-sync percentage (recordType optional). |

Example output

Report: example.com
═══════════════════

DNS records
───────────
┌───────────────┬───────────────────────────────┐
│ A             │ 93.184.216.34                 │
│ NS            │ a.iana-servers.net            │
│               │ b.iana-servers.net            │
└───────────────┴───────────────────────────────┘

SSL certificate
───────────────
┌────────────────────┬──────────────────────────┐
│ Subject            │ CN=example.com           │
│ Issuer             │ DigiCert Inc             │
│ Days until expiry  │ 180                      │
└────────────────────┴──────────────────────────┘

Advisories
──────────
No issues found.

JSON export

--export-json writes a structured document (schema described in docs/09-json-export-api.md) suitable for feeding into other tools or automation.

Requirements

• Node.js 18 or higher
• Internet access for lookups

License

MIT — see LICENSE.