298e884ec3* chore: add stable spec release 2026-01-26 - Use git mv to copy specification from draft to specification/2026-01-26/apps.mdx (preserves history) - Update status from 'Draft' to 'Stable (2026-01-26)' - Add specification version table to README - Update Resources section with links to both stable and draft specs * chore: bump version to 1.0.0 - Update main package version from 0.4.2 to 1.0.0 - Update all example package versions to 1.0.0 - Regenerate package-lock.json * prettier * chore: align protocol version with spec release 2026-01-26 - Add 'Protocol Version: 2026-01-26' to spec header - Update LATEST_PROTOCOL_VERSION from '2025-11-21' to '2026-01-26' - Update spec examples to use '2026-01-26' protocol version - Add '2025-11-21' to SUPPORTED_PROTOCOL_VERSIONS for backwards compatibility * chore: update spec references to stable 2026-01-26 - Update typedoc.config.mjs navigation link - Update docs/overview.md spec links (10 occurrences) - Update plugins/mcp-apps/skills/create-mcp-app/SKILL.md spec link - Update src/spec.types.ts @see links - Update AGENTS.md spec path - Regenerate src/generated/schema.ts with updated links * chore: simplify versioning - first stable release - Remove backwards compatibility version (2025-11-21) - this is the first stable release - Remove redundant 'Protocol Version' header - spec version IS the protocol version * chore: add history reference comment to stable spec
96 lines
3.1 KiB
Markdown
96 lines
3.1 KiB
Markdown
# Example: System Monitor App
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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.
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<table>
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<tr>
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<td><a href="https://modelcontextprotocol.github.io/ext-apps/screenshots/system-monitor-server/01-initial-state.png"><img src="https://modelcontextprotocol.github.io/ext-apps/screenshots/system-monitor-server/01-initial-state.png" alt="Initial state" width="100%"></a></td>
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<td><a href="https://modelcontextprotocol.github.io/ext-apps/screenshots/system-monitor-server/02-cpu-data-accumulated.png"><img src="https://modelcontextprotocol.github.io/ext-apps/screenshots/system-monitor-server/02-cpu-data-accumulated.png" alt="CPU data accumulated" width="100%"></a></td>
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<td><a href="https://modelcontextprotocol.github.io/ext-apps/screenshots/system-monitor-server/03-extended-cpu-history.png"><img src="https://modelcontextprotocol.github.io/ext-apps/screenshots/system-monitor-server/03-extended-cpu-history.png" alt="Extended CPU history" width="100%"></a></td>
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</tr>
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</table>
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## MCP Client Configuration
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Add to your MCP client configuration (stdio transport):
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```json
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{
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"mcpServers": {
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"system-monitor": {
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"command": "npx",
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"args": [
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"-y",
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"--silent",
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"--registry=https://registry.npmjs.org/",
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"@modelcontextprotocol/server-system-monitor",
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"--stdio"
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]
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}
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}
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}
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```
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### Local Development
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To test local modifications, use this configuration (replace `~/code/ext-apps` with your clone path):
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```json
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{
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"mcpServers": {
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"system-monitor": {
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"command": "bash",
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"args": [
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"-c",
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"cd ~/code/ext-apps/examples/system-monitor-server && npm run build >&2 && node dist/index.js --stdio"
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]
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}
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}
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}
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```
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## Features
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- **Per-Core CPU Monitoring**: Stacked area chart showing individual CPU core utilization over a 1-minute sliding window
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- **Memory Usage**: Horizontal bar gauge with color-coded thresholds (green/yellow/red)
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- **System Info**: Hostname, platform, and uptime display
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- **Auto-Polling**: Automatically starts monitoring on load with 2-second refresh interval
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- **Theme Support**: Adapts to light/dark mode preferences
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## Running
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1. Install dependencies:
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```bash
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npm install
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```
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2. Build and start the server:
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```bash
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npm run start:http # for Streamable HTTP transport
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# OR
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npm run start:stdio # for stdio transport
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```
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3. View using the [`basic-host`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/basic-host) example or another MCP Apps-compatible host.
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## Architecture
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### Server (`server.ts`)
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Exposes a single `get-system-stats` tool that returns:
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- Raw per-core CPU timing data (idle/total counters)
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- Memory usage (used/total/percentage)
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- System info (hostname, platform, uptime)
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The tool is linked to a UI resource via `_meta.ui.resourceUri`.
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### App (`src/mcp-app.ts`)
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- Uses Chart.js for the stacked area chart visualization
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- Polls the server tool every 2 seconds
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- Computes CPU usage percentages client-side from timing deltas
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- Maintains a 30-point history (1 minute at 2s intervals)
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- Updates all UI elements on each poll
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