Web Monitor#

Track web pages for changes. Stores snapshots, computes diffs, supports CSS selectors.

Triggers#

Activate this skill when the user wants to:

• Watch a website for content changes
• Track price changes, new posts, or updated content on a page
• Set up page change alerts or notifications
• Check if a site has been updated since last visit
• Monitor a specific section of a page (with CSS selector)

NOT For#

• Real-time alerting on dynamic topics — use the topic-monitor skill for news/topic monitoring with importance scoring
• Full page archival — this tracks diffs, not full crawl archives
• JavaScript-heavy SPAs — the monitor fetches raw HTML; dynamic content rendered by JS may not be captured accurately
• Monitoring APIs or webhooks — use cron + exec for structured data endpoints

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Quick Start#

bash

# Add a URL to watch
uv run --with beautifulsoup4 python scripts/monitor.py add "https://example.com" --name "Example"

# Add with CSS selector (monitor specific section)
uv run --with beautifulsoup4 python scripts/monitor.py add "https://example.com/pricing" -n "Pricing" -s ".pricing-table"

# Check all watched URLs for changes
uv run --with beautifulsoup4 python scripts/monitor.py check

# Check one specific URL
uv run --with beautifulsoup4 python scripts/monitor.py check "Example"

# List watched URLs
uv run --with beautifulsoup4 python scripts/monitor.py list

# View last diff
uv run --with beautifulsoup4 python scripts/monitor.py diff "Example"

# View current snapshot
uv run --with beautifulsoup4 python scripts/monitor.py snapshot "Example" --lines 50

# Remove
uv run --with beautifulsoup4 python scripts/monitor.py remove "Example"

Commands#

CommandArgsDescriptionadd``<url> [-n name] [-s selector]Add URL to watch, take initial snapshotremove``<url-or-name>Stop watching a URLlist``[-f json]List all watched URLs with statscheck``[url-or-name] [-f json]Check for changes (all or one)diff``<url-or-name>Show last recorded diffsnapshot``<url-or-name> [-l lines]Show current snapshot

Output Symbols#

• 🔔 CHANGED — page content changed (shows diff preview)
• ✅ No changes
• 📸 Initial snapshot taken
• ❌ Error fetching

Data#

Stored in ~/.web-monitor/ (override with WEB_MONITOR_DIR env var). For OpenClaw workspace integration, set WEB_MONITOR_DIR=$WORKSPACE/data/web-monitor (where $WORKSPACE is your agent workspace path).

• watches.json — watch list config
• snapshots/ — stored page content + diffs

Tips#

• Use --selector to monitor specific elements (prices, article lists, etc.)
• Use --format json for programmatic checking (heartbeat integration)
• CSS selectors require beautifulsoup4 (included via --with flag)
• Text is normalized to reduce noise from timestamps, whitespace, ads