mcp-toolbelt

29 pay-per-call DNS, SEO, SSL, security, and dev tools for AI agents.

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What it can do

    What data it sees

    Do you need an account

    No: the server works without sign-in

    29 pay-per-call DNS, SEO, SSL, security, and dev tools for AI agents. x402, no API key.

    How to connect

    How to connect mcp-toolbelt to Claude

    The server address to paste into Claude settings:

    https://papacasper.com/mcp

    1. Open Claude (claude.ai or the desktop app).
    2. Go to Settings → Connectors.
    3. Click Add custom connector.
    4. Paste the server address copied below into Remote MCP server URL and click Add.
    5. In a chat, click + → Connectors and switch the new connector on.

    Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

    Authorization

    After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

    How to connect mcp-toolbelt to ChatGPT

    The server address to paste into ChatGPT settings:

    https://papacasper.com/mcp

    1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
    2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
    3. Open Settings → Connectors and click Create.
    4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
    5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
    6. In a new chat open + → Apps/Connectors and enable the connector.

    OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

    Authorization

    On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

    How to connect mcp-toolbelt to Cursor

    The server address to paste into Cursor settings:

    https://papacasper.com/mcp

    Fastest: click Open in Cursor below and confirm the prompt.

    Manually:

    1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
    2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
    3. Save the file. The server appears in the MCP list; authorize it there if asked.

    Authorization

    If the service needs sign-in, an authorize button appears next to the server in the MCP list.

    Server tool list (29)

    Raw names from tools/list. Only developers need these.

    url_to_markdownFetch a URL and return its main text content as clean, readable plain text/markdown-ish output. Strips scripts, styles, and HTML tags.
    security_headers_auditFetch a URL and audit its response for security-relevant HTTP headers (HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy). Flags missing/misconfigured headers with a score.
    redirect_chain_checkFollow a URL through every HTTP redirect hop and report the full chain, final destination, and issues like redirect loops, too many hops, or HTTPS-to-HTTP downgrades.
    page_performance_checkFetch a URL and measure time-to-first-byte, total fetch time, and response size. Flags missing compression, missing Cache-Control, oversized payloads, and slow TTFB.
    cors_policy_checkSend a probe request with a foreign Origin header to a URL and report its CORS response headers. Flags wildcard-origin + credentials combinations and arbitrary-origin reflection, both common CORS misconfigurations.
    structured_data_extractFetch a URL and extract structured data deterministically: JSON-LD blocks, OpenGraph/meta tags, and optional caller-supplied CSS-selector fields (e.g. { price: '.product-price', title: 'h1' }). No LLM involved — pure HTML parsing via CSS selectors, so results are exact matches only, not summarized or inferred.
    tech_stack_fingerprintFetch a URL and fingerprint its likely tech stack from response headers (server, x-powered-by, x-generator) and HTML markers (generator meta tag, framework/CMS-specific script or class patterns). Best-effort — not exhaustive, no additional paths are probed.
    ai_crawler_policy_checkCheck a site's robots.txt for explicit directives targeting known AI crawlers (GPTBot, ClaudeBot, CCBot, PerplexityBot, Google-Extended, Bytespider, Amazonbot, and others used for LLM training or AI search/answer products), and check for an llms.txt file. Useful for publishers deciding whether their content policy toward AI crawlers matches their intent, or for auditing a competitor's stance.
    seo_auditFetch a URL and run an SEO audit: title/meta description length, canonical tag, Open Graph + Twitter Card tags, html lang attribute, viewport meta, heading structure, image alt-text coverage, internal/external link counts and generic-anchor-text detection, robots meta (noindex/nofollow), structured data (JSON-LD) presence, and robots.txt/sitemap.xml presence.
    check_robots_sitemapCheck whether a site has a valid robots.txt and sitemap.xml, and return their raw contents (truncated).
    broken_link_checkCrawl a site starting from a URL (same-origin pages only, bounded by maxPages) and check every linked URL for broken status codes. Returns broken links with the page(s) they were found on. Note: some external sites (e.g. social platforms) block automated HEAD/GET requests and may show up as false positives.
    favicon_manifest_checkCheck a site for favicon, apple-touch-icon, web app manifest, and theme-color presence — a quick completeness check for browser/OS chrome and PWA metadata.
    json_ld_schema_validatorFetch a URL, extract every JSON-LD (<script type="application/ld+json">) block, and validate basic structure — @context/@type presence plus required fields for common schema.org types (Article, Product, Organization, WebSite, LocalBusiness, BreadcrumbList, FAQPage). Reports per-block errors rather than failing the whole call on one bad block.
    sitemap_url_validatorParse a site's sitemap.xml (following one level of sitemap-index nesting) and check the HTTP status of every listed URL. Concurrency-limited, capped at 200 URLs checked per call. Reports broken/redirecting URLs found in the sitemap.
    domain_health_checkCheck a domain's registration expiry (via WHOIS) and DNS health: nameservers, A/AAAA, MX, SPF, and DMARC records. Flags common misconfigurations.
    dns_propagation_checkQuery a DNS record for a domain against several major public resolvers (Google, Cloudflare, Quad9, OpenDNS) in parallel and compare the answers. Flags mismatches, which usually mean propagation is still in progress after a DNS change.
    ip_geolocation_asn_lookupResolve a hostname to its IPv4 addresses and look up each one's ASN, network prefix, country code, and network owner via Team Cymru's DNS-based WHOIS service (no API key). Country-level only — not city/street geolocation.
    email_deliverability_checkDeep-dive email deliverability check for a domain: MX records + reverse-DNS (PTR) on each MX host, common DKIM selector probing, SPF lookup-count (RFC 7208 caps at 10), DMARC policy strength, and DNSBL blacklist lookups (Spamhaus Zen, SpamCop, Barracuda) on MX IPs. Note: public-resolver DNSBL queries are frequently rate-limited or blocked by Spamhaus, so a `listed: null` result means "unknown", not "clean" — treat null results as inconclusive, not as a clean bill of health.
    domain_availability_checkCheck whether a domain is registered, plus scan common typo-squat variants (adjacent-key substitution, letter omission/doubling, transposition) across popular TLDs (.com, .net, .org, .io, .co, .ai, .app, .dev) for brand-protection or domain-flipping research. WHOIS-based; capped at 40 variants checked per call for latency.
    ssl_cert_checkConnect to a host over TLS and report its certificate's expiry date, days remaining, issuer, and subject.
    check_open_portsTCP-connect scan a host for open ports. Defaults to a list of ~20 common service ports (SSH, HTTP/S, mail, DBs, etc.) if none are given. For checking your own infrastructure's exposure — capped at 100 ports per call.
    websocket_endpoint_checkTest a WebSocket endpoint (ws:// or wss://): attempts the handshake, reports success/failure, time-to-open in ms, and close code/reason. Useful for verifying a WebSocket server is reachable and completes its upgrade handshake before you wire real traffic to it.
    domain_reportBundle: runs seo_audit, domain_health_check (WHOIS + DNS: nameservers, A/AAAA, MX, SPF, DMARC), and email_deliverability_check (DKIM, SPF lookup-count, DMARC strength, DNSBL) against a domain in one call, one charge. Cheaper than calling the three tools separately. Each sub-check reports independently, so a failure in one doesn't void the others.
    safe_browsing_checkCheck a URL against Google Safe Browsing's malware/phishing/unwanted-software/PUA blocklists. Requires GOOGLE_SAFE_BROWSING_API_KEY to be configured server-side (free Google Cloud API key).
    ssl_labs_gradeFull SSL Labs-style TLS assessment: overall letter grade, protocol support (TLS 1.0-1.3), cipher strength, certificate chain issues, and known vulnerabilities (Heartbleed, POODLE, etc.) for each endpoint. Slower than ssl_cert_check (can take up to ~90s on a cold cache; SSL Labs caches results for 24h server-side).
    pagespeed_insightsRun Google's real PageSpeed Insights (Lighthouse + Chrome UX Report) against a URL: performance score, Core Web Vitals (LCP, CLS, INP/TBT), and real-user field data where available. Authoritative version of a local timing check — hits Google's own infrastructure. Works without an API key at low volume; set GOOGLE_PAGESPEED_API_KEY server-side for higher throughput.
    package_vulnerability_checkLook up a package (optionally pinned to a version) against OSV.dev's aggregated vulnerability database (GitHub Advisories, PyPA, RustSec, Go vuln DB, etc.) for known CVEs/advisories. Supports npm, PyPI, crates.io, RubyGems, Go, Maven, NuGet, and Packagist ecosystems. Useful before adding a dependency.
    github_repo_health_checkCheck a GitHub repository's health signals: stars, forks, open issues, license, archived/disabled status, and days since last push. Flags likely-abandoned or unlicensed repos. Useful before depending on a repo.
    email_address_validateValidate a single email address: RFC syntax check, MX record lookup on the domain, disposable/temporary-email-provider detection, and role-account detection (info@, admin@, etc.). Per-address check — different from email_deliverability_check, which audits a whole domain's sending reputation (SPF/DKIM/DMARC/PTR/DNSBL).