Ask Claude "why is my PC slow?" and get a real answer — not generic advice.

PCCheck is an MCP server that gives Claude read-only eyes into your computer: hardware specs, live CPU/GPU/RAM load, temperatures, disk space hogs, startup bloat, crash history, wifi quality, and a real speed test. Claude stops guessing and starts diagnosing.

🧑‍⚕️ "Your GPU is fine and your CPU is idling — but Chrome is holding 9GB of RAM, your C: drive is 96% full, and there's a 20GB VM image in Downloads you probably forgot about. Delete that and you'll feel the difference." — the kind of answer this unlocks

What you can ask

• 🔍 "Run a full checkup on my PC"

• 🐌 "Why is my computer so slow right now?"

• 📉 "My PC got slower lately — what changed?"

• 💾 "What's eating my disk space?"

• 🎮 "Can my PC run Cyberpunk 2077 at 1440p?" / "Why does my game stutter?"

• 💥 "Why did my PC crash yesterday?"

• 📶 "Is my wifi the problem, or my internet provider?"

• ⚡ "How fast is my internet actually?"

• 🔥 "Is my PC running too hot?"

• 🧹 "Roast my startup programs."

• 🔋 "Should I replace my laptop battery?"

What you need

The Claude Desktop app (Windows or Mac — the free plan works) or Claude Code. The claude.ai website and the mobile app can't run local extensions — they can't see your PC.

PCCheck is Windows-first (crash logs, antivirus status, startup toggles are Windows-only for now); specs, performance, disk, network, and speed checks also work on macOS and Linux.

Install

Option 1 — Claude Desktop, one click (recommended)

1. Download pccheck.mcpb from the latest release

2. Double-click it (or drag into Claude Desktop → Settings → Extensions)

3. Click Install. No terminal, no Node.js, nothing else.

Check it worked: ask Claude "run a full checkup on my PC." The first time, Claude will ask permission for each tool — click Allow. (PCCheck also adds one-click prompts to Claude Desktop's + menu: Full PC checkup, Why is my PC slow?, Free up disk space.)

Option 2 — Claude Code (one command)

claude mcp add pccheck -- npx -y pccheck-mcp

Option 3 — any MCP client (manual config)

{
  "mcpServers": {
    "pccheck": {
      "command": "npx",
      "args": ["-y", "pccheck-mcp"]
    }
  }
}

On Windows, if your client needs it: "command": "cmd", "args": ["/c", "npx", "-y", "pccheck-mcp"].

Note: npx install requires the package on npm — until pccheck-mcp is published there, use the .mcpb release file (Option 1) or clone + npm run build + point your config at dist/index.js.

What Claude sees (15 tools)

Privacy & safety — read this, it's honest

• Read-only by design. No tool can change, delete, install, or configure anything on your system. The worst PCCheck can do is look. The single exception to "writes nothing": what_changed keeps one snapshot file in ~/.pccheck so it can tell you what changed later — delete it anytime. (~1,500 lines of TypeScript, 3 runtime dependencies — auditable in one sitting.)

• PCCheck itself sends nothing about you anywhere. No telemetry, no accounts, no external APIs. Its only network activity: the latency test in network_check (standard pings to your router, 1.1.1.1, 8.8.8.8) and speed_test, which downloads throwaway data from Cloudflare's public speed endpoint — nothing is uploaded.

• But be clear about how MCP works: results Claude asks for become part of your Claude conversation, which is processed by Anthropic like anything else you type. Depending on what you ask, that can include:

  If Claude calls…	Your conversation will contain…
  system_overview	PC model, hostname, hardware specs
  scan_folder_sizes	folder/file names (incl. your Windows username in paths)
  installed_software	names of installed programs
  network_check	your wifi network name (SSID)
  crash_report	crash-log excerpts

  Don't want something seen? Don't ask about it — tools only run when Claude calls them for your request, and you can see every call in the chat.

• No admin rights needed. Everything works as a normal user (Windows hides CPU temperature from non-admin processes — GPU temp still works).

• File and program names on your disk are treated as data, not instructions — but as with anything an AI reads, weirdly-named files could try to influence the conversation. Read-only design caps the blast radius.

FAQ

Can it delete/change/"fix" things itself? No. Every tool is read-only by design — Claude diagnoses and tells you how to fix things yourself. That's a feature, not a limitation.

Does it work on claude.ai in my browser? No — local extensions need the Claude Desktop app or Claude Code.

Does the free Claude plan work? Yes.

Mac/Linux? Yes for specs, performance, disk, network, speed test, battery. Crash logs, antivirus, and startup-toggle detail are Windows-only right now.

How do I uninstall? Claude Desktop: Settings → Extensions → PCCheck → Remove. Claude Code: claude mcp remove pccheck.

Troubleshooting

• "CPU temperature unavailable" — Windows blocks this for non-admin processes; it's expected. GPU temperature (NVIDIA) still works.

• Claude doesn't show the tools — fully quit Claude Desktop (system tray → Quit) and reopen; extensions load at startup.

• npx install fails on Windows — use the cmd /c variant shown above, or the .mcpb file which needs no Node at all.

• A scan times out — every tool is time-boxed on purpose; ask Claude to try again with a smaller scope (a subfolder instead of all of C:\) or a longer time budget.

Development

git clone https://github.com/jjackk0k/pccheck-mcp
cd pccheck-mcp
npm install
npm run build
npm run smoke   # exercises all 15 tools over real stdio JSON-RPC

CI runs the same smoke suite on Windows and Linux runners for every push.

Roadmap

• Deeper macOS/Linux parity (startup items, installed apps with sizes)

• Optional LibreHardwareMonitor bridge for full sensor data (CPU temp without admin)

• "What changed since yesterday?" snapshot diffing

License

MIT — see LICENSE.

Built for the person whose family asks them to fix the computer. Now Claude can be that person.