The Hopi MCP server,
connected in one click.
Free UK calculators, converters and validators (tax, VAT, stamp duty, dates, units), read-only. Connect the official Hopi MCP server to Claude, ChatGPT, or Cursor through gate — one gateway URL, no config files, security-checked.
Free to start · No credit card · No hosting needed
Add Hopi to your AI in one minute
Pick your client. Copy, paste, done — or let gate handle sign-ins and policies for you.
claude mcp add --transport http hopi https://mcp.hopi.co.uk/mcpRun in your terminal, then restart Claude Code.
Hopi · https://mcp.hopi.co.uk/mcp
What your AI can do with Hopi
Real prompts you can type the moment it's connected — no setup, no docs to read.
“Use “hopi_add_working_days”: Add or subtract a number of working days (Monday to Friday) from a start date, optionally skipping England and Wales bank holidays. Dates us.”
“Use “hopi_age_calculator”: Work out an exact age from a date of birth, as of today or an optional 'as of' date. Dates use the YYYY-MM-DD format. Returns the age in yea.”
“Use “hopi_alcohol_unit_calculator”: Work out UK alcohol units in a drink from its ABV (percentage) and volume (millilitres), using units = ABV x ml / 1000. Optionally give the.”
“Use “hopi_alphabetical_order”: Sort the lines of a block of text into alphabetical order. Blank lines are dropped. Uses natural en-GB ordering so numbers within lines sort.”
How secure is the Hopi MCP server?
Every server in the gate directory has to pass the same four checks before your AI can touch it. Here's how Hopi holds up.
Security grade B
gate scanned 195 tools on Sep 23, 2026. A few things are worth a look before you connect.
- mediumhopi_env_to_json: References secrets or data exfiltration
Official endpoint
Operated by Hopi (co.uk) at its documented MCP endpoint — not a third-party mirror or community re-host.
No sign-in needed
This server only exposes public data — no account and no credentials are involved when you connect.
Scanned before it goes live
gate checks every tool for prompt injection, hidden instructions, data-exfiltration hints, and over-broad permissions before the server is available through your gateway.
Watched for drift
If Hopi adds or changes tools later, gate re-scans and alerts you — before your AI acts on the change.
Connected in three steps
Connect your gate
Add one gateway URL to Claude, ChatGPT, or any MCP client. One-time setup, about two minutes.
Pick Hopi
Choose Hopi in the gate directory. No sign-in needed.
Use it anywhere
Hopi's tools are live in every AI client you've connected — with rules and logging built in.
Free to start · No credit card · No hosting needed
The actual tools Hopi exposes
Fetched live from the official endpoint and re-checked daily by gate — not marketing copy.
hopi_add_working_days — Add or subtract a number of working days (Monday to Friday) from a start date, optionally skipping England and Wales bank holidays. Dates us
hopi_age_calculator — Work out an exact age from a date of birth, as of today or an optional 'as of' date. Dates use the YYYY-MM-DD format. Returns the age in yea
hopi_alcohol_unit_calculator — Work out UK alcohol units in a drink from its ABV (percentage) and volume (millilitres), using units = ABV x ml / 1000. Optionally give the
hopi_alphabetical_order — Sort the lines of a block of text into alphabetical order. Blank lines are dropped. Uses natural en-GB ordering so numbers within lines sort
hopi_angle_converter — Convert an angle from one unit to another. Units: deg (degrees), rad (radians), grad (gradians), turn (full turns). Source: https://hopi.co.
hopi_area_converter — Convert an area from one unit to another. Units: sqm (square metres), sqft (square feet), sqyd (square yards), acre (acres), ha (hectares),
hopi_aspect_ratio_calculator — Aspect ratio helper. In 'simplify' mode, give width and height to get the simplified W:H ratio, decimal ratio and nearest common ratio. In '
hopi_average_calculator — Work out the mean, median, mode, sum, count, minimum and maximum of a list of numbers. Provide the numbers separated by spaces, commas, semi
+ 187 more tools once connected
Who runs the Hopi MCP server?
The Hopi MCP server at a glance
https://mcp.hopi.co.uk/mcpQuestions, answered
Is there an official Hopi MCP server?
Yes — Hopi operates its own remote MCP server at mcp.hopi.co.uk. gate connects you to that official endpoint and adds security scanning, per-tool access rules, and an activity log on top.
How do I connect Hopi to Claude or ChatGPT?
Add gate's gateway URL to your AI client once, then pick Hopi in the directory. No account or sign-in is needed. From then on, Hopi's tools are available in every client you've connected to gate.
Do I need to host anything?
No. Hopi runs the server, and gate is fully managed. You just connect one URL — there's nothing to install, deploy, or maintain.
Is the Hopi MCP server safe to connect?
It's the vendor's official endpoint, and gate scans its tools for prompt injection and hidden instructions before it goes live, re-checks it whenever it changes, and lets you allow, block, or require approval for every single tool.
Is it free?
Yes — you can get started with gate for free and connect Hopi in minutes. No credit card required.
Connect more than just Hopi
Every server below works through the same gateway URL — connect once, add tools anytime.
Squarespace DomainsDesignView →Set up Hopi in: Claude · Claude Code · ChatGPT · Cursor · VS Code