Products / MCP server

Free, open source

Check a site from inside Claude and Cursor

Two ways in. The remote server needs only a URL and gives five free tools, scoring a site on the same five areas as the free check. The local npm package runs four tools on your machine, including the sixteen gates. Free, no account.

In plain words

If you use Claude or Cursor, this teaches them to look at a website for you. You ask in ordinary words, "why does ChatGPT recommend my competitor and not me", and the assistant goes and reads the site, scores it out of 100 and tells you what is actually missing. It is free, there is no account, and nothing you check is stored.

Who it is for

What you actually do

  1. Paste one block into your Claude or Cursor settings
  2. Ask the assistant about a site in plain words
  3. Read what it found and change what it named

Free

MIT licence, no account, no key, nothing stored. Node 20 or newer

Copy the command →

What you need before you start

WhatCostWhy
Node.js 20 or newer Free The server runs on your own machine. Node.js is free software from nodejs.org, and most people who use Claude Desktop or Cursor already have it.
An MCP client Free Claude Desktop, Cursor, or anything else that speaks MCP. The server is not tied to any one of them.

What you get

How it works

  1. Add one block. Paste the server into claude_desktop_config.json or .cursor/mcp.json. Nothing to install: npx fetches it.
  2. Ask in words. Why does ChatGPT recommend my competitor? Is my llms.txt correct? The assistant picks the tool and reads the result.
  3. Act on it. Every finding names what was found on the page, so the next step is a change rather than a guess.

Install

npx -y @operstack/mcp

What it is not for

Can an AI read this site and quote it Eight technical signals per site, measured live Before 32% After 100% → 15 sites 13 of 15 sites served nothing but llms.txt Measured 11.09.2026 and 12.09.2026. Every signal is one curl request away. oper-stack.com
The same eight signals, measured live on 11 and 12 September 2026 on 15 of our sites: the 13 content sites plus oper-stack.com and oper-stack.ru. This is what the MCP server reads when your assistant asks it to check a site.

Why I share this

I sell property to international buyers. It is a niche where a single advertising lead costs more than most products on this page, and where the buyer reads for weeks before writing to anyone. For years the enquiries came from paid ads. Then I built content sites that answer the questions those buyers ask, and the enquiries started arriving on their own: from Google first, then, more and more, from ChatGPT and Perplexity, which quote the pages when someone asks.

The numbers are on the cases page, site by site: clicks from Google up 249 percent across thirteen sites in more than ten countries, the first 28 days of June against the 28 days to 25 September 2026, and a new site that went from 3 clicks in its first 28 days to 98. Every tool on this page is a piece of the pipeline behind those sites, stripped of my data and packaged so you can run it in your own niche: the method for finding what a market actually searches for, the page shapes that get quoted, and the checks that stop a bad page from going live.

I am not a software company. I am an operator who got tired of paying for every lead, and these are the tools I use every week. If they work for you the way they work for me, tell me; if they do not, the refund policy says exactly what comes back and when.

Maksim Shchegolev, founder of OperStack · the numbers behind this · refund policy

Frequently asked questions

Does it send my files anywhere?
No. The gates tool reads files on your own machine and reports back in the same conversation. The site tools fetch public pages, which is exactly what a search engine does.
Do I need an API key?
No. There is no account and no key. Every figure comes from what any stranger can read on a site for nothing.
Will the numbers match your paid report?
Yes, they run through the same package. A free tool that disagrees with the paid one is the fastest way to lose the reader.
What happens if I mistype the address?
It refuses. A site that did not answer gets a refusal rather than a page of findings about nothing.

Further reading

Other products

Work done for you, agreed in writing before payment: Fix · Foundation. See services on request.

What a finished report looks like: the sample report, a real paid audit, anonymised.