FernTool MCP Server

About FernTool

Hosted remote MCP server (streamable HTTP, JSON responses) from ferntool.com. No sign-up, no API key, free to use; please stay under about 40 network lookups per minute.

18 tools: get_my_ip, lookup_ip, batch_lookup_ip (up to 100 IPs, with Tor/VPN/datacenter flags), validate_ip, whois_lookup (RDAP for domains, IPs and ASNs), dns_lookup, reverse_dns, subnet_calc (IPv4/IPv6), get_current_time, convert_timestamp, date_calc (days between dates, add/subtract, working days), convert_timezone (DST aware), random_number and pick_random (cryptographically secure), make_qr_code (static SVG), count_words, estimate_ai_cost and ai_service_status.

The same functions are available as a plain JSON API with an OpenAPI spec at https://www.ferntool.com/openapi.json.

FernTool tools (23)

Read from the live server on Oct 26, 2026. These are the tools your AI assistant can call once connected.

get_my_ip

Return the public IP address (and ISP, ASN, location, timezone) of the caller as seen by FernTool. Note: for remote agents this is the IP of the machine calling the MCP server.

lookup_ip

Validate an IPv4/IPv6 address and return its version, scope (public/private/loopback/...), country, ASN and network owner (DB-IP Lite + IPtoASN data).

validate_ip

Check whether a string is a valid IPv4 or IPv6 address and classify it.

batch_lookup_ip

Look up 1-100 IPv4/IPv6 addresses at once. Each result has version, scope, country, timezone, ASN, network owner and flags (is_tor, is_datacenter, provider).

whois_lookup

WHOIS via RDAP for a domain (registrar, created/expiry dates, status, nameservers, DNSSEC), an IP address (network name, range, owner org, country, abuse contact) or an ASN like AS13335.

dns_lookup

Resolve DNS records for a domain via Cloudflare 1.1.1.1 DNS-over-HTTPS. Types: A, AAAA, MX, TXT, NS, CNAME, SOA (default: all).

reverse_dns

Reverse DNS (PTR) lookup for an IPv4/IPv6 address, with forward-confirmation check.

subnet_calc

IPv4/IPv6 CIDR subnet calculator: network, netmask, wildcard, broadcast, first/last usable host, total and usable addresses, block type.

estimate_ai_cost

Estimate token count and USD API cost of a text across major AI models (OpenAI GPT, Anthropic Claude, Google Gemini), and whether it fits each context window. Token counts are approximate. Pass text, or tokens directly.

make_qr_code

Create a static QR code (never expires) for a URL, Wi-Fi string (WIFI:T:WPA;S:name;P:pass;;), mailto:, tel: or any text up to 2000 characters. Returns an SVG string plus a ferntool.com image URL that renders the same code.

count_words

Exactly count words, characters (with and without spaces), sentences and paragraphs in a text, with reading/speaking time and the most repeated words. Use this instead of estimating counts yourself.

get_current_time

Get the exact current date and time (you cannot know it otherwise). Returns Unix seconds and milliseconds, ISO 8601 in UTC and in the requested IANA time zone, weekday, ISO week and day of year.

convert_timestamp

Convert a Unix timestamp (seconds, milliseconds, microseconds or nanoseconds, auto-detected) to a readable date, or a date/time string (e.g. 2026-12-25 09:00, read in the given time zone unless it has its own offset) to a Unix timestamp. Al

date_calc

Exact calendar maths. With end: days between two dates (plus weeks, months+days, weekdays Mon-Fri, weekend days). With add_days/add_weeks/add_months/add_years (negative to subtract): the resulting date and weekday; business_days=true skips

convert_timezone

Convert a time between time zones with daylight saving applied (you cannot do this reliably yourself). from/to accept IANA zones (Africa/Johannesburg), common abbreviations (SAST, EST, PST, GMT, CET, IST=India, CST=US Central) or big cities

random_number

Fair, cryptographically secure random integers (you cannot produce real randomness yourself). min and max are inclusive. unique=true for no repeats (raffles, lotto, picking winners). For a coin flip use min 0, max 1; for dice use min 1, max

pick_random

Fairly pick random winners from a list, shuffle a list, or split people into random even teams, using a cryptographically secure generator (you cannot choose fairly at random yourself). Use for giveaways, raffles, "who goes first", random o

check_dns_propagation

Check whether a DNS change has spread: asks the domain's own authoritative name server (when reachable) and 8 big public resolvers (Cloudflare, Google, OpenDNS, AdGuard, NextDNS, Control D, CleanBrowsing, AliDNS) over DoH, marks which are u

check_email_security

Can someone fake (spoof) email from a domain? Reads SPF (counts the 10 DNS-lookup limit, follows includes), DMARC (policy, pct, reports, inherited from the parent domain) and DKIM keys (common selectors, or the one given), detects the email

check_website_status

Is a website down? Resolves its DNS and loads the URL once (10 s timeout) from FernTool's Cloudflare edge, then returns verdict (up/down), reason (ok, blocked_bot, page_not_found, server_error, timeout, tls, dns_nxdomain...), HTTP status, r

trace_redirects

Where does a link really go? Follows a URL (short links like bit.ly, tracking links, QR code links) hop by hop without a browser: every redirect with status code (301/302/307/308/meta refresh), final URL and page title, plus warning signs (

check_website_legit

Is this website legit or a scam? Follows the URL (redirects included) and returns plain-language warning signs: domain age from RDAP (scam shops are usually days or weeks old), look-alike brand names (banks, SARS, couriers, Takealot, PayPal

ai_service_status

Live status of AI services (ChatGPT/OpenAI, Claude, Gemini API, GitHub Copilot, Perplexity, Cohere) read from their official status pages, cached ~60s. level is up, degraded, down or unknown.

How to connect FernTool to Claude, Cursor or VS Code

FernTool runs as a hosted remote MCP server at https://www.ferntool.com/mcp. Add that URL to your MCP client's config (Claude Code, Cursor, Windsurf or VS Code) and the tools appear immediately, no install required.

{
  "mcpServers": {
    "ferntool": {
      "url": "https://www.ferntool.com/mcp"
    }
  }
}

Claude Code: claude mcp add --transport http ferntool https://www.ferntool.com/mcp. Servers that require OAuth or an API key will prompt on first use.