ext-apps/examples/system-monitor-server/README.md
Jonathan Hefner 4ca20f21c4
Smoothen the process of getting started (#103)
* Restructure threejs-server README to match marketing examples

- Update title format to "Example: Three.js App"
- Constrain screenshot width using table layout
- Add Features section with key capabilities
- Reorganize Running section with Tool Input subsection
- Add Architecture section describing server and app components
- Remove implementation-focused sections (WidgetProps, Creating a New Widget)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Add bun as devDependency to example packages

npm install now automatically installs bun, eliminating the need for
separate installation instructions. Removed manual bun install step
from customer-segmentation-server README.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Add start:http and start:stdio npm scripts to examples

For the 6 examples supporting --stdio transport, add explicit scripts:
- serve:http / serve:stdio for running the server
- start:http / start:stdio for build + serve
- start now aliases to start:http for backward compatibility

Update READMEs to document both transport options.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Default basic-host SERVERS to localhost:3001/mcp

- Change threejs-server default port from 3109 to 3001 for consistency
- Add default SERVERS value in basic-host serve.ts
- Document SERVERS env var in basic-host README

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Improve Examples section in README

Frame the three basic examples as foundational starting points and
add a link to the examples directory for additional demo apps.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
2025-12-09 16:15:32 +01:00

2.4 KiB

Example: System Monitor App

A demo MCP App that displays real-time OS metrics with a stacked area chart for per-core CPU usage and a bar gauge for memory.

Initial state CPU data accumulated Extended CPU history

Features

  • Per-Core CPU Monitoring: Stacked area chart showing individual CPU core utilization over a 1-minute sliding window
  • Memory Usage: Horizontal bar gauge with color-coded thresholds (green/yellow/red)
  • System Info: Hostname, platform, and uptime display
  • Auto-Polling: Automatically starts monitoring on load with 2-second refresh interval
  • Theme Support: Adapts to light/dark mode preferences

Running

  1. Install dependencies:

    npm install
    
  2. Build and start the server:

    npm run start:http  # for Streamable HTTP transport
    # OR
    npm run start:stdio  # for stdio transport
    
  3. View using the basic-host example or another MCP Apps-compatible host.

Architecture

Server (server.ts)

Exposes a single get-system-stats tool that returns:

  • Raw per-core CPU timing data (idle/total counters)
  • Memory usage (used/total/percentage)
  • System info (hostname, platform, uptime)

The tool is linked to a UI resource via _meta[RESOURCE_URI_META_KEY].

App (src/mcp-app.ts)

  • Uses Chart.js for the stacked area chart visualization
  • Polls the server tool every 2 seconds
  • Computes CPU usage percentages client-side from timing deltas
  • Maintains a 30-point history (1 minute at 2s intervals)
  • Updates all UI elements on each poll