Sentinel Web Monitor

Problem

When version numbers, status text, announcements, or configuration values change on a web page, manual refreshes are hard to track over time. Sentinel Web Monitor focuses on a narrower job: given one or more URLs, detect text-content changes and reduce noise from timestamps, ads, or fluctuating numbers.

How it works

It manages monitoring targets through scripts/web_monitor.py, with state stored by default in ~/.web_monitor/state.json. The normal workflow is to register URLs with --add URL, then run --check. The first check only captures a baseline snapshot; later checks report a unified diff, with context controlled by --context. Use --no-save for a read-only comparison that does not update the snapshot, or --reset to discard the baseline and recapture on the next check.

Content extraction removes non-text markup and keeps readable text. --filter accepts regex patterns to suppress volatile changed lines, which helps ignore timestamps or dynamic values. --label gives each target a descriptive name, making --list easier to scan across environments.

Boundaries

It is best suited for text-based page monitoring rather than authenticated sessions, complex client-side rendering, or API-backed data. If content is injected by front-end code, confirm that the monitor captures the rendered DOM text. SSL validation is skipped by default for self-signed or intranet environments, but production use should still consider access control and audit logging.