mcp-page-monitor

mcp-page-monitor

MCP server for monitoring web page changes. Uses Playwright to capture page content, SQLite for snapshot storage, and optional LLM integration for business impact analysis.

Available on npm and the MCPize marketplace.

Tools

monitor_page

Register a URL to watch for changes. Takes an initial snapshot immediately.

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | url | string | yes | URL to monitor | | label | string | no | Human-readable label | | selector | string | no | CSS selector to monitor a specific element | | check_interval_minutes | number | no | Check frequency (1–10080). Default: 60 |

check_changes

Browse a monitored URL with Playwright, capture current content, and diff against the stored snapshot.

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | url | string | yes | URL to check (must be registered first) |

Returns { changed, diff, timestamp } — diff includes added/removed line counts, changed sections, and a unified diff string.

analyze_change

Analyze a page diff using an LLM to summarize what changed and assess business impact.

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | url | string | yes | URL whose changes to analyze | | diff_text | string | no | Provide diff text directly instead of computing from snapshots |

Returns { summary, impact, severity } — severity is low | medium | high | critical.

Falls back to deterministic analysis (pattern matching for pricing changes, errors, policy updates, etc.) when no LLM endpoint is configured.

list_monitored_pages

List all URLs currently being monitored.

remove_monitored_page

Stop monitoring a URL.

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | url | string | yes | URL to stop monitoring |

Installation

npm install mcp-page-monitor

Or run directly:

npx mcp-page-monitor

Requirements

• Node.js 22+
• Chromium browser (Playwright uses it for page rendering)

Install Playwright browsers if needed:

npx playwright install chromium

Configuration

Claude Desktop / Cursor / MCP Client

Add to your MCP client config:

{
  "mcpServers": {
    "page-monitor": {
      "command": "npx",
      "args": ["mcp-page-monitor"],
      "env": {
        "PLAYWRIGHT_CHROMIUM_PATH": "/usr/bin/chromium-browser"
      }
    }
  }
}

Environment Variables

| Variable | Default | Description | |----------|---------|-------------| | PAGE_MONITOR_DB_PATH | ~/.mcp-page-monitor/page-monitor.db | SQLite database location | | PLAYWRIGHT_CHROMIUM_PATH | /usr/bin/chromium-browser | Path to Chromium executable | | CHROME_PATH | — | Fallback browser path | | PAGE_TIMEOUT_MS | 30000 | Page navigation timeout | | LLM_ENDPOINT | — | LLM API endpoint for analyze_change (e.g. OpenAI-compatible /v1/chat/completions) | | LLM_API_KEY | — | Bearer token for LLM endpoint | | LLM_MODEL_ID | gpt-4o-mini | Model to use for analysis | | LLM_SOURCE_SYSTEM | mcp-page-monitor | Source identifier sent to LLM |

How It Works

1. Register a page with monitor_page — takes an initial snapshot via headless Chromium
2. Check for changes with check_changes — fetches current content and computes a line-level diff (LCS-based) against the last snapshot
3. Analyze changes with analyze_change — sends the diff to an LLM for business impact assessment, or uses built-in heuristics (pricing detection, error detection, policy changes) when no LLM is available

All snapshots are stored in a local SQLite database with WAL mode enabled for concurrent access.

Development

git clone https://github.com/deialedin/mcp-page-monitor
cd mcp-page-monitor
npm install
npm run build       # Compile TypeScript
npm test            # Run 26 tests
npm run dev         # Watch mode with tsx

License

MIT