Spec Driven Development
by formulahendry
MCP Server that facilitates spec-driven development workflows, not just Vibe Coding.
Runs on your computer★ 440MITUpdated 14 months ago
Install
Opencu
Overview
Description from the maker (original English)
Independent local computer-use engine and MCP server for macOS, Windows, Linux and Android
PopNx MCP’s three pillars
These three are never merged into one score: opinions, measurements and popularity are different things.
- User voiceiNo reviews yetReviews open together with accounts in a later step
- Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
- UsageiNot measured yet★ –
What you can do with it
We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.
- Connection: Runs on your computer
- Transport: stdio
- Category: Other
Install
Pick the AI app you use, then copy the settings.
Before you install
- Basic checks: 1 of 1 passed
- Runs on your computer with your user’s permissions (files, network, apps).
- The registry lists no key to fill in.
You need
- npmNode.js installed (for the npx command)
Which app do you use?
Pick your app above. We remember it, so next time the button says “Install in …”.
Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json
{
"mcpServers": {
"opencu": {
"command": "npx",
"args": [
"-y",
"@z10/opencu"
]
}
}
}Run this in your terminal
claude mcp add opencu -- npx -y @z10/opencuOr copy the settings yourself
Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json
{
"mcpServers": {
"opencu": {
"command": "npx",
"args": [
"-y",
"@z10/opencu"
]
}
}
}Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.
Or copy the settings yourself
Paste into .vscode/mcp.json in your project
{
"servers": {
"opencu": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@z10/opencu"
]
}
}
}Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.
This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.
Your choice stays on this device in a cookie; no account needed.
These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.
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 7, 2026
- ✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account Daily-AC, which owns the repo
- … Not checked yet
Still maintained
We have not read this repo from GitHub yet
- … Not checked yet
Has a licence
We have not read this repo from GitHub yet
- – 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
Compared with others in Otheri
- More stars than 0% of the other 32696 servers in this category
- Published to the registry more recently than 96% of the other 32696 servers in this category
- Basic checks equal to or better than 100% of the other 32696 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 Opencu safe?
It passed 1 of 1 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 –, and the latest version (0.9.1) reached the registry yesterday.
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: Spec Driven Development, Remote Desktop Commander, LexPact UK Contracts
Alternatives
Servers in the same category from other makers, sorted by stars.
Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi
Remote Desktop Commander
by desktop-commander
Remote Desktop Commander: use files, terminal and processes on your own computers from any AI app.
Runs in the cloud★ 211Updated 2 days ago
Install
LexPact UK Contracts
by Idadabhai
Generate UK-law contracts: NDA, service, freelance, recruiter terms of business, IR35.
Runs on your computerUpdated today
Install
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.
OpenCU
Computer use for any AI agent, on your own machine.
https://github.com/user-attachments/assets/5da04b21-47fe-44c4-9d3d-e2b3a2e9a9c6
Re-created in code from a real session.
OpenCU is an MCP server that lets Claude Code, Codex or any other MCP client read
and operate the apps on macOS, Windows, Linux and Android. It runs locally, needs no account
or model key, and the person at the keyboard can stop it at any time.
Install · Connect · Measured · Limitations · 简体中文
Why OpenCU
It works beside you. On macOS, input goes to the target app's process and window. Your cursor stays where it is and the app in front keeps the keyboard.
It can have a screen of its own. Start the agent desktop and the agent works on a virtual display (macOS) or in a separate session (Windows), which you watch in an ordinary window.
You stay in charge. You can always stop it: the Stop button on macOS, a physical Escape on Windows and Linux, three presses of volume-down on Android. On Windows, Linux and Android it will not take the foreground within 10 seconds of your last input. A stopped connection never restarts on its own.
It is measured. On Windows tasks that can only be done through the UI, the same agent passed 7 of 8 trials with OpenCU and 2 of 8 with a shell and screenshots. Details below.
It is yours. MIT licensed, with no account, no proprietary runtime and nothing hosted. The agent you already use brings the model.
Install
Windows · PowerShell, as your normal user, no administrator rights
irm https://github.com/Daily-AC/opencu/releases/latest/download/install.ps1 | iexLinux · x86_64 with glibc, X11 desktops
curl -fsSL https://github.com/Daily-AC/opencu/releases/latest/download/install.sh | shmacOS · Apple silicon, macOS 14 or later, Node.js 22+
npm install -g @z10/opencuopencu setup # grant Accessibility and Screen Recording
Android · preview, Android 14 or later, driven from a computer over adb (USB or wireless debugging)
npm install -g @z10/opencu # Apple silicon Macs, with adb; other computers build from source, see the Android guideopencu android doctor
To check an installation, run opencu doctor (on Windows and Linux, the command from the table below). Platform guides: macOS · Windows · Linux · Android. Connecting your own host to Android: Android integration.
Connect your agent
OpenCU is a stdio MCP server. The command to register is:
| Platform | Command |
|---|---|
| macOS | opencu |
| Windows | %LOCALAPPDATA%\OpenCU\bin\opencu.cmd |
| Linux | ~/.local/share/opencu/bin/opencu |
| Android | opencu android (one phone on adb, or set ANDROID_SERIAL) |
# Claude Codeclaude mcp add --scope user opencu -- opencu
Codex
codex mcp add opencu -- opencu
On Windows, Linux and Android, use the command from the table instead of opencu.
Any other MCP client (on Android, add "args": ["android"]):
{"mcpServers": { "opencu": { "command": "opencu" } } }
Then ask your agent to do something in an app. It starts by reading the app with get_app_state.
What the agent can do
| Tool | What it does |
|---|---|
list_apps | List running and launchable apps |
get_app_state | Read a window's accessibility tree, with a screenshot on request; launches the app if needed |
click · drag · scroll | Act on an element by its index, or on screenshot coordinates |
type_text · paste · press_key | Type Unicode text, paste, send keys and shortcuts |
set_value · select_text · perform_secondary_action | Change values and use an element's own actions |
activate_app | Bring an app to the front when a step needs it |
run_actions | Run up to 16 actions in one call and return one final state |
agent_desktop | Start, check or stop the agent desktop |
select_text is macOS and Linux only. Linux has no agent_desktop.
Input requires a fresh observation of the same app, and every error starts with a stable code such as STOPPED_BY_PERSON. Details are in Tools and the engine contract.
Measured
With and without OpenCU. The same agent and model, with a shell and screenshots alone or with OpenCU added:
| Platform | Tasks | Shell and screenshots | With OpenCU |
|---|---|---|---|
| Windows 11 VM | 4 tasks that need the UI: a form, an installer, Save As, an interrupting popup | 2/8 | 7/8 |
| Windows 11 VM | 3 Office and OBS tasks that can be scripted around | 6/6 | 3/6 |
| Linux XFCE container | 5 desktop tasks | 10/10 | 10/10, 40–65% faster inside app windows |
On the scriptable tasks the shell-only agent wrote LibreOffice and OBS scripts instead of using the UI; two of OpenCU's three failures there were a modal-dialog defect fixed in 0.3.2. Evidence: Windows, Linux.
Against open-computer-use. The same agents, models and tasks with OpenCU and with iFurySt/open-computer-use 1.1.2 at its default settings:
| Platform | Tasks | OpenCU | open-computer-use |
|---|---|---|---|
| Linux | 5 desktop tasks, 2 trials each | 10/10 | 9/10 |
| Windows 11 VM | 4 UI-only tasks, 2 trials each | 7/8 | 4/8 |
| macOS VM (MacArena subset) | 10 tasks, 1 trial each | 4/10 | 4/10, the same tasks |
- Linux: the two Firefox tasks took OpenCU 244 and 96 seconds (median) and open-computer-use 872 and 552. open-computer-use did not list Firefox until the agent turned on the AT-SPI bus itself, and in one trial its
set_valueandtype_textleft the Firefox entries empty without an error. - Windows: in all eight open-computer-use trials the agent also wrote its own Win32 input code, and its four passes completed input that way. It wrote none with OpenCU. open-computer-use ran behind a bridge on the VM (1.5 to 7 seconds per call), so its Windows timings are not comparable.
- macOS: both passed the same four tasks. On those, the agent took 544 seconds in total with OpenCU and 1,498 with open-computer-use; median click time was 292 ms against 2,029 ms. The OpenCU build in that VM was 0.2.0.
The samples are small and each platform used one model. We did not test open-computer-use's locked-screen mode, its background input on covered Chrome windows, or its global pointer setting (evidence).
Platforms
| macOS | Windows | Linux | Android | |
|---|---|---|---|---|
| Install | npm, Apple silicon | Prebuilt x64, unsigned | Prebuilt x64 | npm on Apple silicon Macs, otherwise build from source; runs over adb |
| Input | Background, to the target app only | Foreground, after 10 s without your input | Foreground, after 10 s without your input | Foreground, after 10 s without your input |
| Agent desktop | Virtual display with a watch-only preview | Separate session in a window | Not available | Virtual display; watch-only preview with the optional phone app |
| Screen locked | Refused; the agent desktop pauses | Refused; the agent desktop keeps indexed clicks and values | Refused | Refused |
Stopping it
- macOS: the V in the menu bar has Stop. In agent desktop mode, the preview's Stop button does the same.
- Windows and Linux: a physical Escape stops input for the rest of the connection, and your own input during an action stops that action. The Windows agent desktop also has a Stop button.
- Android: press volume-down three times within 1.5 seconds. While the agent works on its background screen, the optional phone app's status island also has Stop. Touching the main screen during an action there stops that action.
- A person's stop is final for the connection. Agents must never reconnect around it.
OpenCU is a person-facing brake, not a sandbox: the agent's apps share your account and files, and any local process that can run opencu uses its permissions.
Limitations
- macOS: Apple silicon only. The package is signed with OpenCU's own certificate and is not notarized, so install it with npm, not a browser download. macOS asks about once a month whether OpenCU may keep capturing the screen. It cannot operate a locked Mac.
- Windows: the package is unsigned, so SmartScreen or Defender may warn. Outside the agent desktop, input uses the foreground.
- Linux: X11 only; Wayland is refused. Input uses the foreground.
- Android: a preview, tested on one phone (OPPO PGBM10, Android 14). It runs from a computer over adb; the npm package installs only on Apple silicon Macs, and other computers build from source. The phone app is optional and only shows status, a preview and Stop.
- Custom-drawn apps such as Blender, and windows in the Stage Manager strip, need the foreground.
The full list, with measurements, is in Limitations.
Documentation
- Platform guides: macOS, Windows, Linux, Android
- Tools and the engine contract, with the Windows and Linux contracts
- Host integration, for programs that start OpenCU on an agent's behalf
- Limitations and measured behavior
Development
npm testpython3 scripts/test-native.py node scripts/verify-gui.mjs
verify-gui.mjs builds two disposable AppKit fixtures, keeps one in the foreground and operates the other in the background through the MCP server. On Windows, node scripts/verify-gui-win.mjs uses disposable WinForms and Chrome fixtures and takes the foreground.
python3 scripts/package-opencu.py builds a self-contained archive with Node and the MCP dependencies for your own Macs, signed with your local identity, and python3 scripts/verify-release.py checks it offline.
License
Original OpenCU code is available under the MIT License. Bundled open source dependencies retain their own licenses. No license for proprietary third party software is included or implied.