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