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Filename Latest commit message Latest commit date
Jonathan Hefner 996f028e7f Add missing refresh-stats tool to system-monitor-server 
The `mcp-app.ts` UI was calling a `refresh-stats` tool that didn't exist
on the server, causing the example to fail. This was introduced in
PR #131 when the squash merge included the client-side change but lost
the server-side tool registration.

Fixes #200

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-12 11:56:09 -06:00
..
src feat: use structuredContent with outputSchema in example servers (#220) 2026-01-12 14:25:16 +00:00
mcp-app.html Add color-scheme meta tag to all example apps 2025-12-15 11:42:18 -08:00
package.json chore: release 0.3.1 (#224) 2026-01-09 18:22:27 +00:00
README.md docs: add tool visibility and restructure _meta.ui (#131) 2025-12-16 21:47:40 +00:00
server-utils.ts fix: add error handling for server startup failures (#236) 2026-01-11 16:52:55 +00:00
server.ts Add missing refresh-stats tool to system-monitor-server 2026-01-12 11:56:09 -06:00
tsconfig.json Add system-monitor-server example 2025-12-04 14:32:41 -06:00
vite.config.ts Add system-monitor-server example 2025-12-04 14:32:41 -06:00

README.md

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.ui.resourceUri.

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