Page Monitor

page-monitor-mcp-server

Deterministic web page change monitoring MCP server with SHA-256 snapshot evidence. Free single-page diff, no key required; 7x24 scheduled monitoring via a Cat1 API key from https://toplformater.click.

What it does

• Noise-filtered deterministic diff (cat1_diff_page): compares a target web page (or local HTML) against a baseline, stripping dynamic noise -- <script>/<style>, random nonce/request-id, dynamic counters, relative timestamps, and JSON indentation differences -- and returns the normalized text's SHA-256 hashes, a structured change summary, and a unified diff. Free, no key, no account, no card.
• SHA-256 cryptographic evidence chain: every cat1_diff_page call records baseline_sha256, target_sha256, diff_patch_sha256, structured_changes, and unified_diff, so any result can be independently re-fetched and hash-verified. No hallucinated changes.
• 7x24 scheduled monitoring gate (cat1_schedule_monitor): requests or validates a Cat1 API key for always-on scheduled monitoring. Without a key it returns directions to get one at https://toplformater.click (USD 29/month, 7-day free trial, no card required). With a key it only checks the key format locally (^cat1_(?:live|trial)_[A-Za-z0-9]{16,64}$); it never calls an external payment or verification endpoint, never fabricates a verification result, and never pretends to run the schedule locally. Actual 7x24 monitoring is performed by our own cloud service. The tool honestly reports local_scheduler_started: false and online_verified: false.

Tools

Tool	Key required	Purpose
cat1_diff_page	No	Free single-page noise-filtered diff + SHA-256 evidence. Inputs: target_url (required), baseline_source (optional), baseline_sha256 (optional).
cat1_schedule_monitor	Optional (gate)	Scheduled-monitoring key gate + directions. Inputs: target_url (required), interval_minutes (optional, default 15), alert_email (optional), api_key (optional, or CAT1_API_KEY env var).

Quickstart

Requirements

• Python 3.9+ (standard library only, zero third-party dependencies), or Docker for the OCI image.

Option A -- Run from source

git clone https://github.com/jhfg31410-ai/page-monitor-mcp-server.git
cd page-monitor-mcp-server
python3 server.py

Option B -- Run with Docker (after the image is published)

docker run -i --rm ghcr.io/jhfg31410-ai/page-monitor-mcp-server:0.1.0

Claude Desktop / Cursor configuration

Copy claude_desktop_config.example.json into your MCP client config and set the server path (or the Docker image). Example (source):

{
  "mcpServers": {
    "page-monitor-mcp-server": {
      "command": "python3",
      "args": ["/path/to/page-monitor-mcp-server/server.py"],
      "env": {
        "CAT1_API_KEY": "YOUR_CAT1_KEY_HERE_OPTIONAL"
      }
    }
  }
}

Pricing

• Single-page diff (cat1_diff_page): free, no key, no account, no card.
• 7x24 scheduled monitoring: USD 29/month, 7-day free trial, no card required. Get a formal API key at https://toplformater.click. All payments go through our own site (Paddle / PayPal); this server never handles payments.

Files

• server.py -- MCP stdio server (implements initialize, tools/list, tools/call, and the key gate).
• engine.py -- noise-filtering and semantic diff core (SHA-256, structured diff).
• server.json -- Official MCP Registry descriptor (public repo and Docker image not yet created/published).
• Dockerfile -- OCI image build (Python 3.12-slim, zero dependencies).
• requirements.txt -- package list (zero third-party dependencies, Python >= 3.9 stdlib only).
• claude_desktop_config.example.json -- Claude Desktop / Cursor mount example (placeholder key only).
• fixtures/t0_sample.html, fixtures/t1_sample.html -- local diff test HTML snapshots.

Local test commands

List tools (tools/list)

printf '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05"}}\n{"jsonrpc":"2.0","id":2,"method":"tools/list","params":{}}\n' | python3 server.py

Free diff test (cat1_diff_page, no key)

printf '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"cat1_diff_page","arguments":{"baseline_source":"fixtures/t0_sample.html","target_url":"fixtures/t1_sample.html"}}}\n' | python3 server.py

Key-gate test (cat1_schedule_monitor)

No key (returns directions):

printf '{"jsonrpc":"2.0","id":4,"method":"tools/call","params":{"name":"cat1_schedule_monitor","arguments":{"target_url":"https://news.ycombinator.com/","interval_minutes":5}}}\n' | python3 server.py

With a format-matching demo key (local format check only; no network verification, no local scheduling):

printf '{"jsonrpc":"2.0","id":5,"method":"tools/call","params":{"name":"cat1_schedule_monitor","arguments":{"target_url":"https://news.ycombinator.com/","interval_minutes":5,"api_key":"cat1_trial_DemoFormatCheckOnly9999"}}}\n' | python3 server.py

Status

• Version 0.1.0. Server name page-monitor-mcp-server.
• This repository is prepared for publication to the Official MCP Registry (server.json included) and for listing on Glama / PulseMCP. The public repository, Docker image, and registry submission are not yet published.
• License: MIT (see LICENSE).