OpenMEP duct sizing

Name: OpenMEP duct sizing
Author: samarmstrong

by samarmstrongversion 0.2.0i★ 0iRuns on your computer

Registry nameio.github.samarmstrong/openmep

How to install

What it does

Deterministic HVAC duct sizing at a fixed or Manual D friction rate; grades existing ducts.

Connects Runs on your computer
Account or key No key needed
Category Other

Install

Pick the AI app you use, then copy the settings.

Passed 3/3 checks · Runs on your computer · ✓ Commands checked Nov 14, 2026

First: which AI do you use?

ClaudeWeb · app · phoneChatGPTWebClaude CodeTerminalCursorCode editorVS CodeCode editorOtherOther apps

Pick your app and the steps appear below.

Works with Claude, with some setup first

Install Node.js on your computer first (one time) · Only the Claude desktop app (Windows or Mac), not the web or phone

Let AI install it

Copy this message into a Claude chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server OpenMEP duct sizing for Claude on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): { "mcpServers": { "openmep": { "command": "npx", "args": [ "-y", "@openmep/mcp" ] } } } 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) No key is needed. 5) Do what we agreed, then check that the OpenMEP duct sizing tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Open the Claude desktop app’s settings file
SettingsDeveloperEdit Config
Done

Paste these settings and save the file

{
  "mcpServers": {
    "openmep": {
      "command": "npx",
      "args": [
        "-y",
        "@openmep/mcp"
      ]
    }
  }
}

Done

Quit Claude and open it again
Done
Try it
Use OpenMEP duct sizing and tell me what you can do for me, then show me one thing
✓ If Claude says it is using OpenMEP duct sizing or shows a OpenMEP duct sizing tool in the answer, you are connected

Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version

ChatGPT cannot connect OpenMEP duct sizing yet

OpenMEP duct sizing runs on your computer, but ChatGPT can only connect servers that run on the web

What you can do instead

A · Use an app that can connect OpenMEP duct sizing

Steps for Claude →Install Node.js on your computer first (one time) · Only the Claude desktop app (Windows or Mac), not the web or phone
Steps for Claude Code →Install Node.js on your computer first (one time)
Steps for Cursor →Install Node.js on your computer first (one time)
Steps for VS Code →Install Node.js on your computer first (one time)

B · Others in Other that work with ChatGPT

Picked from the most used in the same category, only ones that connect by address with no key

Hostinger✓ ChatGPT
World Monitor✓ ChatGPT
Svelte MCP✓ ChatGPT

Works with Claude Code, with some setup first

Install Node.js on your computer first (one time)

Let AI install it

Copy this message into a Claude Code chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server OpenMEP duct sizing for Claude Code on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): claude mcp add --scope user openmep -- npx -y @openmep/mcp 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) No key is needed. 5) Do what we agreed, then check that the OpenMEP duct sizing tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Open Terminal
Mac: press Command+Space and type Terminal · Windows: open PowerShell
Done

Paste this command and press Enter

claude mcp add --scope user openmep -- npx -y @openmep/mcp

Done

Type /mcp in Claude Code
You should see OpenMEP duct sizing listed as connected
Done
Try it
Use OpenMEP duct sizing and tell me what you can do for me, then show me one thing
✓ If Claude Code says it is using OpenMEP duct sizing or shows a OpenMEP duct sizing tool in the answer, you are connected

Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with Cursor, with some setup first

Install Node.js on your computer first (one time)

Let AI install it

Copy this message into a Cursor chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server OpenMEP duct sizing for Cursor on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): { "mcpServers": { "openmep": { "command": "npx", "args": [ "-y", "@openmep/mcp" ] } } } 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) No key is needed. 5) Do what we agreed, then check that the OpenMEP duct sizing tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Click this button to open Cursor
Open in Cursor
Cursor asks you to confirm; click Install
Done
Open the AI chat in Cursor in Agent mode
Done
Try it
Use OpenMEP duct sizing and tell me what you can do for me, then show me one thing
✓ If Cursor says it is using OpenMEP duct sizing or shows a OpenMEP duct sizing tool in the answer, you are connected

Menu names checked against Cursor’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with VS Code, with some setup first

Install Node.js on your computer first (one time)

Let AI install it

Copy this message into a VS Code chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server OpenMEP duct sizing for VS Code on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): { "servers": { "openmep": { "type": "stdio", "command": "npx", "args": [ "-y", "@openmep/mcp" ] } } } 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) No key is needed. 5) Do what we agreed, then check that the OpenMEP duct sizing tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Click this button to open VS Code
Open in VS Code
VS Code asks you to confirm; click Install
Done
Open the AI chat in VS Code in Agent mode
Done
Try it
Use OpenMEP duct sizing and tell me what you can do for me, then show me one thing
✓ If VS Code says it is using OpenMEP duct sizing or shows a OpenMEP duct sizing tool in the answer, you are connected

Menu names checked against VS Code’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Other apps that use MCP, such as Windsurf, Zed or Gemini CLI, each add servers differently. See how in the app list.

See every app that uses MCP →

JSON settings are under “For developers” below

Stuck? Ask people who use OpenMEP duct sizing💬 Discussion →

For developers: Terminal commands and JSON settings

Installed on your computer

Claude Code

claude mcp add --scope user openmep -- npx -y @openmep/mcp

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "openmep": {
      "command": "npx",
      "args": [
        "-y",
        "@openmep/mcp"
      ]
    }
  }
}

Cursor (~/.cursor/mcp.json)

{
  "mcpServers": {
    "openmep": {
      "command": "npx",
      "args": [
        "-y",
        "@openmep/mcp"
      ]
    }
  }
}

VS Code (mcp.json)

{
  "servers": {
    "openmep": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@openmep/mcp"
      ]
    }
  }
}

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

At a glance

GitHub stars i: 0
Downloads per weeki: 52/wk
Licence i: MIT
Connection: Runs on your computer
Transport: stdio
Latest versioni: 0.2.0
Categoryi: Other
Published to registryi: Oct 8, 2026
Code last changedi: Oct 8, 2026
Maker: samarmstrong
Packages: npm: @openmep/mcp
Repo: samarmstrong/openmep
Registry status: Active

Which apps can use it

Based on how this server connects and on each app’s own docs, checked Nov 10, 2026.

Run on your computer in

Claude Goose LM Studio Msty Studio Cherry Studio Cursor VS Code + GitHub Copilot Visual Studio Windsurf (Devin Desktop)Zed Kiro Cline Continue JetBrains AI Assistant Claude Code Codex CLI Gemini CLI OpenCode nodecode Warp LibreChat Raycast

All apps, with pros and cons →

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 15, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account samarmstrong, which owns the repo
✓ Pass
Still maintained
Code last changed 38 days ago
✓ Pass
Has a licence
Uses MIT
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Published vulnerabilities (OSV.dev)

Not checked yet

What we check → · JSON

Makers: ask for a re-check or report wrong info

Discussion

Ask, share a tip or report that it does not work. Sorted by what people marked helpful.

No posts yet. Be the first to ask or share.

Posts here are written by users, not the PopNx team.

User reviews

No reviews yet

Compared with others in Otheri

More stars than 0% of the other 19878 servers in this category
Published to the registry more recently than 54% of the other 19878 servers in this category
Basic checks equal to or better than 100% of the other 19878 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is OpenMEP duct sizing safe?

It passed 3 of 3 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed 38 days ago, and the latest version (0.2.0) reached the registry 38 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: World Monitor, openstatus, Oh My Posh Validator, Strata, Jitsu

Similar alternatives

Same category, other makers, commands already checked. Official ones first, then by stars.

Reading a card:↓ Downloads per weeki★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

World Monitor

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by koala73Widely used★ 90.6KUpdated yesterday

Runs in the cloud✓ service owner · worldmonitor.app

How to connect

openstatus

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Oh My Posh Validator

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by JanDeDobbeleerWidely used★ 23.8K Stars for the whole repoUpdated 26 days ago

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How to connect

Strata

MCP server for progressive tool usage at any scale (see https://klavis.ai)

by Klavis-AIGrowing★ 5.8KUpdated 14 months ago

Runs in the cloudRepo archived✓ klavis.ai

How to connect

Jitsu

Manage Jitsu data pipelines: destinations, streams, connections, functions, live events.

by jitsucomWidely used★ 5.1KUpdated 4 months ago

Runs in the cloud✓ service owner · jitsu.com

How to connect

World Monitor — Runs in the cloud, nothing to install · No key needed
openstatus — Runs in the cloud, nothing to install · No key needed
Oh My Posh Validator — Runs in the cloud, nothing to install · No key needed
Strata — Runs in the cloud, nothing to install · No key needed
Jitsu — Runs in the cloud, nothing to install · No key needed

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

@openmep/mcp

An MCP server that gives any agent OpenMEP's deterministic HVAC duct sizing. No editor, CAD host, account, or network access: the agent describes the ducts, the engine sizes them.

"mcpServers": { "openmep": { "command": "npx", "args": ["-y", "-p", "@openmep/mcp", "openmep-mcp"] } } }

Claude Code: claude mcp add openmep -- npx -y -p @openmep/mcp openmep-mcp. Requires Node.js 24+. Transport: stdio.

Tools

Tool	Input	Returns
`size_duct`	`cfm`, optional `role` (`main`/`branch`/`runout`), `airflowType` (`supply`/`return`/`exhaust`/`outside-air`), `existing` section (`{diameterIn}` or `{shape: rect\	oval, widthIn, heightIn}`)	Recommended standard round diameter, velocity, friction; for an existing section its circular equivalent and `ok`/`undersized`/`oversized`
`size_duct_network`	`items`: terminals with `requiredCfm`, segments (optionally with `existing` and `lengthFt`), fittings (optionally `equivalentLengthFt`), equipment, linked by `connectedItemRefs`; optional `fan` (`externalStaticInWg`, `componentLossesInWg`)	Every loaded segment's CFM, role, recommendation, and grade; with `fan`, the Manual D `design` (available static, total effective length, friction rate, governing paths); findings for missing CFM, disconnected terminals, dangling references, mixed systems, undersized and oversized runs, friction rate outside 0.06–0.18

Both tools are read-only and idempotent. Invalid input comes back as a tool error naming the field (NetworkInputError [invalid-item]: items[2].requiredCfm: ...) so the model can correct it.

Example prompt that works in a fresh Claude Code session with only this server:

I have a furnace feeding a supply trunk that tees into two runouts: bedroom 1

needs 120 CFM, bedroom 2 needs 90 CFM, and the living room is fed off the trunk

end at 200 CFM. All drawn as 6 inch round. One return grille in the hall at

410 CFM on a 10 inch drop. Is anything undersized?

The agent builds the network in one size_duct_network call and reports 7, 6, and 8 in runouts, an 11 in trunk, and a return drop just under size at 10 in.

Engineering basis and limits

Equal friction at 0.08 in. w.g./100 ft, or at the Manual D rate derived from the blower's available static pressure when fan and lengths are given, with role-based velocity caps per system, rounded up to standard round diameters; see @openmep/hvac-domain for the formula, sources, and what is excluded (fitting losses, static pressure summation, fan selection). Airflow is a design input the server never estimates. Treat results as preliminary sizing for an engineer to review.

The server uses the official MCP TypeScript SDK and speaks the initialize-handshake protocol revisions (through 2025-11-25), which current clients support.

Library

import { createOpenMepServer } from "@openmep/mcp";

await createOpenMepServer().connect(transport); // any MCP server transport

OpenMEP duct sizing

What it does

Install

Install Node.js (if you don’t have it)

Open the Claude desktop app’s settings file

Paste these settings and save the file

Quit Claude and open it again

Try it

What you can do instead

Install Node.js (if you don’t have it)

Open Terminal

Paste this command and press Enter

Type /mcp in Claude Code

Try it

Install Node.js (if you don’t have it)

Click this button to open Cursor

Open the AI chat in Cursor in Agent mode

Try it

Install Node.js (if you don’t have it)

Click this button to open VS Code

Open the AI chat in VS Code in Agent mode

Try it

Installed on your computer

At a glance

Which apps can use it

Related guides

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Published vulnerabilities (OSV.dev)

Discussion

User reviews

Compared with others in Otheri

Common questions

Similar alternatives

World Monitor

openstatus

Oh My Posh Validator

Strata

Jitsu

README from the maker

@openmep/mcp

Tools

Engineering basis and limits

Library