SENTINEL is a lightweight, zero-dependency macOS session protection utility designed for professionals who run long operations — overnight renders, ML training, large transfers, CI pipelines, DJ sets, or any workflow where your machine sleeping means lost work.

With one click, SENTINEL prevents idle sleep, monitors system health in real time, manages timed sessions, and gives you a live dashboard — all without opening Terminal or babysitting caffeinate commands.

SENTINEL offers three launch methods. All resolve to the same daemon — choose based on your preference.

What Happens at Launch

SENTINEL operates in four modes. Transitions are controlled via the dashboard buttons.

Session Presets are one-click session profiles that combine a protection mode, optional duration, and optional reminder into a single action. Click a preset and SENTINEL configures everything for you.

Built-In Presets

Using Presets

Presets appear as a horizontal bar at the top of the dashboard during standby. Click any preset to instantly activate that session profile. Pro-locked presets display a lock icon on the Free tier. Presets are also available in the menu bar dropdown under Quick Start.

Custom Presets (Pro)

Pro users can create unlimited custom presets. In the dashboard settings area, click Manage Presets to create, edit, or delete custom profiles. Each custom preset lets you configure a name, icon, duration, reminder, and auto-away behavior. Custom presets are saved to ~/.sentinel/presets.json and persist across sessions.

API Commands

The SENTINEL dashboard is a single-page web interface served by the local daemon. It polls the daemon every 3–5 seconds for real-time data and requires no internet connection.

Dashboard Indicators

Dashboard Controls

Session Stats

Below the main controls, five stat cards display cumulative session analytics: total sessions, total hours, sessions this week, average duration, and longest session. These stats update every 30 seconds from the daemon's session history.

Session History (Pro)

Click View Session History to expand a scrollable log of recent sessions. Each entry shows date/time, duration, mode, preset used, session name (if set), and how the session ended. Pro users can view the full list and name active sessions using the pencil icon. Free users see the stats bar only — the full session list requires Pro.

About Panel

At the bottom of the dashboard, a compact info bar shows the current version, license tier, and company name. Click it to expand a detail panel with the daemon PID, config path, session count, and links to the Operations Guide, gotsentinel.com, and issue reporting.

First-Launch Welcome

When you open SENTINEL for the first time, a welcome overlay introduces the product with three quick-start steps. Click Get Started to dismiss it. The overlay never shows again after dismissal.

SENTINEL continuously monitors your Mac's vital signs. Stats update every 3 seconds during active sessions and every 10 seconds in standby.

SENTINEL sends native macOS notifications for key session events. Notifications appear in Notification Center and play the Glass sound (configurable). Enable or disable notifications via the notifications_enabled config key.

Notification Events

Configuration

SENTINEL can optionally monitor local services (development servers, databases, AI backends) to give you visibility into what's running alongside your protected session.

Adding a Service

Edit ~/.sentinel/config.json and add entries to the connected_services array:

{
  "connected_services": [
    {
      "name": "Ollama",
      "url": "http://localhost:11434",
      "health_path": "/"
    },
    {
      "name": "FastAPI Backend",
      "url": "http://localhost:8000",
      "health_path": "/health"
    }
  ]
}

SENTINEL polls each service every 10–15 seconds and displays its status (online/offline) in the dashboard's services panel.

SENTINEL stores its runtime configuration at ~/.sentinel/config.json. This file is created automatically on first run with safe defaults.

Update Checker

SENTINEL checks gotsentinel.com once every 24 hours for new versions. If an update is available, a banner appears in the dashboard and menu bar with a download link. The first check runs 30 seconds after daemon startup.

This check fetches a single static JSON file — zero user data is transmitted. No user agent, no cookies, no query parameters, no identifying information of any kind. If you are offline, the check is silently skipped.

To disable update checks entirely, set check_for_updates to false in ~/.sentinel/config.json.

SENTINEL uses a freemium model. The Free tier includes full session protection, system monitoring, timed sessions, away mode, Quick Protect preset, 2 connected services, auto-start on login, and macOS notifications. Pro unlocks Time Guardian reminders, session presets, menu bar quick-toggle, unlimited connected services, custom presets, and auto-protect rules.

Feature Comparison

Activating a License

1. Purchase a Pro license from gotsentinel.com
2. Receive your license key via email or download
3. Open the SENTINEL dashboard
4. Scroll to the bottom and click Activate License
5. Paste your full license key into the activation field
6. All Pro features unlock immediately — no restart required

Trial Licenses

Trial keys provide full Pro access for a limited duration (typically 14 or 30 days). The dashboard displays a TRIAL badge with days remaining. When the trial expires, all features revert to the Free tier. You can upgrade to Pro at any time by purchasing and activating a permanent key.

Deactivating a License

To deactivate your license (for example, when moving to a new Mac), scroll to the license section in the dashboard and click Deactivate License. This removes the key from the current machine. You can reactivate on another machine using the same key.

SENTINEL can start automatically when you log into your Mac. This is a free-tier feature — no Pro license required. Once enabled, the daemon launches in the background at login and is ready to protect when you are.

Enabling Auto-Start

1. Open the SENTINEL dashboard
2. Find the Start on Login toggle in the settings area
3. Click to enable — SENTINEL creates a LaunchAgent at:
   ~/Library/LaunchAgents/com.risestudiolabs.sentinel.plist
4. On your next login, SENTINEL starts automatically

The toggle is also available in the menu bar dropdown (Pro).

Disabling Auto-Start

Click the toggle again to disable. SENTINEL removes the LaunchAgent plist automatically. You can also disable manually from Terminal:

launchctl unload ~/Library/LaunchAgents/com.risestudiolabs.sentinel.plist

Troubleshooting

ls ~/Library/LaunchAgents/com.risestudiolabs.sentinel.plist

curl -s http://127.0.0.1:8766/ping

API Commands

SENTINEL's daemon exposes a simple HTTP API on 127.0.0.1:8766. All responses are JSON. The API is designed for the dashboard but can be called by scripts, automations, or other local tools.

GET Endpoints

POST Commands

Example: Script-Based Activation

# Start a 4-hour protected session from Terminal
curl -X POST http://127.0.0.1:8766/cmd \
  -H "Content-Type: application/json" \
  -d '{"cmd": "PROTECT", "duration_s": 14400}'

# Check current status
curl -s http://127.0.0.1:8766/status | python3 -m json.tool

# Deactivate
curl -X POST http://127.0.0.1:8766/cmd \
  -H "Content-Type: application/json" \
  -d '{"cmd": "DEACTIVATE"}'

The Time Guardian is an optional reminder system that nudges you after a set duration — without stopping your session. It's designed for professionals who lose track of time during deep work.

How It Works

When a protected session is active, you can arm a reminder from the dashboard. When the timer fires, SENTINEL shows a prominent banner and sends a macOS native notification with sound. The session continues — nothing is interrupted.

Daemon Commands

Configuration

Optional keys in ~/.sentinel/config.json:

SENTINEL follows a single-daemon architecture. All entry points resolve to one Python process serving both the API and the dashboard.

SENTINEL is evolving from a personal utility into a professional macOS product. Below is the four-phase plan.

Phase A — Production Release (Target: Q2 2026)

• macOS code signing + notarization via Apple Developer Program
• Direct download distribution via gotsentinel.com
• DMG installer with drag-to-Applications flow
• Auto-update mechanism (Sparkle framework or custom)
• Privacy policy and terms of service

Phase B — Feature Expansion (Q3–Q4 2026)

• Native macOS menu bar integration (tray icon with quick controls) — ✓ Shipped v4.5.0
• Login item support (auto-launch on boot) — ✓ Shipped v5.0.0 (as Auto-Start on Login)
• Multi-session profiles (dev, render, meeting, etc.)
• Smart scheduling — auto-protect during calendar blocks
• Usage analytics dashboard (local-only, privacy-first) — ✓ Shipped v5.2.0 (as Session History + Activity Log)
• Webhook/Slack notifications for session events

Phase C — Native Swift Rewrite (2027)

• Full Swift/SwiftUI native app — no Python dependency
• Native Cocoa menu bar agent
• LaunchAgent daemon management
• Apple Silicon optimized
• Potential Mac App Store distribution

Phase D — Platform Expansion (2027+)

• Windows port (PowerShell daemon + native tray app)
• Linux port (systemd service + GTK/web dashboard)
• Team/enterprise tier — centralized dashboard, fleet management

Revenue Model