Northline WebKit

Free. Lists every WebKit tool with its price, required inputs and an example, plus how x402 payment works. Call this first.

{
  "type": "object",
  "properties": {}
}

Fetch any public web page and return clean, readable Markdown (main content only: no scripts, nav or footer) plus title, word count and final URL. Ideal for feeding pages to an LLM. Costs $0.003 USDC on Base per call via x402 (unpaid calls return the x402 PaymentRequired; any x402 MCP client pays automatically).

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "description": "Public http(s) URL (scheme optional)",
      "minLength": 3
    },
    "maxChars": {
      "type": "string",
      "description": "Max markdown characters (1000-50000, default 20000)"
    }
  },
  "required": [
    "url"
  ]
}

Link preview and SEO metadata for any URL: title, description, canonical, language, Open Graph and Twitter card, favicon, RSS/Atom feeds and JSON-LD types, after following redirects. Costs $0.002 USDC on Base per call via x402 (unpaid calls return the x402 PaymentRequired; any x402 MCP client pays automatically).

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "description": "Public http(s) URL (scheme optional)",
      "minLength": 3
    }
  },
  "required": [
    "url"
  ]
}

Every unique outgoing link on a web page (absolute URLs, anchor text, internal vs external), up to 500. Use it to crawl a site or find related pages. Costs $0.002 USDC on Base per call via x402 (unpaid calls return the x402 PaymentRequired; any x402 MCP client pays automatically).

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "description": "Public http(s) URL (scheme optional)",
      "minLength": 3
    },
    "external": {
      "type": "string",
      "enum": [
        "only",
        "exclude"
      ],
      "description": "Filter to only or exclude external links"
    }
  },
  "required": [
    "url"
  ]
}

Is this URL up? HTTP status, full redirect chain, final URL, response time, content type, server/CDN and a security-headers grade (HSTS, CSP, X-Frame-Options...). Costs $0.001 USDC on Base per call via x402 (unpaid calls return the x402 PaymentRequired; any x402 MCP client pays automatically).

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "description": "Public http(s) URL (scheme optional)",
      "minLength": 3
    }
  },
  "required": [
    "url"
  ]
}

DNS records for a domain over DNS-over-HTTPS: A, AAAA, CNAME, MX, TXT, NS, SOA, CAA, SRV, PTR or HTTPS, with TTLs and DNSSEC validation flag. Costs $0.001 USDC on Base per call via x402 (unpaid calls return the x402 PaymentRequired; any x402 MCP client pays automatically).

{
  "type": "object",
  "properties": {
    "domain": {
      "type": "string",
      "description": "Domain name, e.g. example.com",
      "minLength": 3
    },
    "type": {
      "type": "string",
      "enum": [
        "A",
        "AAAA",
        "CNAME",
        "MX",
        "TXT",
        "NS",
        "SOA",
        "CAA",
        "SRV",
        "PTR",
        "HTTPS"
      ],
      "default": "A"
    }
  },
  "required": [
    "domain"
  ]
}

Check an email address or domain before you send: syntax, MX servers, accepts mail?, disposable or free provider, mail provider (Google, Microsoft...), SPF and DMARC policy, with risk flags. Costs $0.002 USDC on Base per call via x402 (unpaid calls return the x402 PaymentRequired; any x402 MCP client pays automatically).

{
  "type": "object",
  "properties": {
    "email": {
      "type": "string",
      "description": "Email address or bare domain"
    }
  },
  "required": [
    "email"
  ]
}

WHOIS for a domain via official RDAP: registered?, registrar, creation/expiry dates, domain age in days, status codes, nameservers, DNSSEC and abuse contact. Spot newly registered (phishing) domains. Costs $0.002 USDC on Base per call via x402 (unpaid calls return the x402 PaymentRequired; any x402 MCP client pays automatically).

{
  "type": "object",
  "properties": {
    "domain": {
      "type": "string",
      "description": "Domain name, e.g. example.com",
      "minLength": 3
    }
  },
  "required": [
    "domain"
  ]
}

May I crawl this URL? Parses robots.txt and answers allowed true/false for your user agent and path, the matching rule, sitemaps, and whether 14 AI crawlers (GPTBot, ClaudeBot, PerplexityBot...) are allowed. Costs $0.001 USDC on Base per call via x402 (unpaid calls return the x402 PaymentRequired; any x402 MCP client pays automatically).

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "description": "Public http(s) URL (scheme optional)",
      "minLength": 3
    },
    "userAgent": {
      "type": "string",
      "default": "*"
    }
  },
  "required": [
    "url"
  ]
}

One-call domain due diligence: RDAP registration (age, registrar, expiry), DNS (A/AAAA/NS/CAA, DNSSEC), email setup (MX/SPF/DMARC), HTTPS reachability with security-headers grade, and risk flags such as newly_registered_lt_30d. Costs $0.005 USDC on Base per call via x402 (unpaid calls return the x402 PaymentRequired; any x402 MCP client pays automatically).

{
  "type": "object",
  "properties": {
    "domain": {
      "type": "string",
      "description": "Domain name, e.g. example.com",
      "minLength": 3
    }
  },
  "required": [
    "domain"
  ]
}