modelcontextprotocol/ext-apps
Watch
1
0
Fork
You've already forked ext-apps
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
ext-apps/examples/system-monitor-server
History
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Jonathan Hefner 79670b4dcd
 Add safeAreaInsets support to all example apps (#202) 
Apply host-provided safe area insets as padding on main containers
across all examples. This ensures content doesn't render under
system UI elements like phone notches.

React apps use `useState` + `onhostcontextchanged` handler with
initial fetch via `getHostContext()` in `useEffect`. Vanilla JS
apps apply padding in the handler and invoke it after `connect()`.

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

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-08 18:03:13 +00:00
..
src Add safeAreaInsets support to all example apps (#202) 2026-01-08 18:03:13 +00:00
mcp-app.html Add color-scheme meta tag to all example apps 2025-12-15 11:42:18 -08:00
package.json Fix build errors in examples (#180) 2025-12-18 11:17:23 +00:00
README.md docs: add tool visibility and restructure _meta.ui (#131) 2025-12-16 21:47:40 +00:00
server.ts Clean up examples (#182) 2025-12-19 11:44:27 +00:00
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