Privacy Policy

Last updated October 21, 2026

Sentinel is a desktop app made by Off By 1 LLC (“we”). It runs on your computer, and most of what it knows stays there. This page explains exactly what leaves your computer, where it goes, and why.

The short version

• Your product list, history, store logins and card details stay on your computer.
• Sentinel has no analytics, tracking or advertising, and no account to sign up for.
• It contacts our servers to check for updates and download store plugins, and, if you activate a license, to check that license.
• If you connect Discord direct messages, our relay stores your Discord user ID until you disconnect.
• We don’t sell or share your information for advertising.

On your computer

Sentinel keeps its data in a folder on your computer:

• macOS: ~/Library/Application Support/Sentinel/
• Windows: %APPDATA%\Sentinel

That folder holds the products you watch, your settings and alert channels, the prices and stock levels Sentinel has seen, and logs. Sentinel prunes old records on its own: check history after 30 days, its activity log after 14 days, and its network log after 2 hours unless you choose a longer period (up to 24 hours) in Settings.

Sensitive details go in your computer’s keychain (Keychain on macOS, Credential Manager on Windows), not in that folder. That includes store logins, card details and billing addresses, proxy passwords, your license key, and your Discord connection. Exports and backups made from Settings never include them.

Discord webhook addresses you add are stored in Sentinel’s local database, because Sentinel needs them to send alerts. Anyone with access to your computer account could read them. Turn on Share-safe when exporting to leave them out.

We can’t see any of this. It never reaches our servers.

What leaves your computer

The stores you watch

To check a product, Sentinel visits its page at the store, the same way your browser would, either directly from your internet connection or through proxies you set up. If you use automatic checkout, Sentinel signs in and places orders with your store account. The store’s own privacy policy covers what it collects from those visits.

Updates and store plugins

When it starts and every 6 hours after that, Sentinel asks our update server whether a new version exists. It also downloads the list of available store plugins and the plugins you install. These requests carry no personal information. If you have a license, plugin downloads include your license token, which identifies your license and device but not you.

Licensing (only if you activate a license)

When you activate a license, and about every 6 hours afterward, Sentinel sends our licensing service:

• your license key, and
• a device fingerprint: a one-way scrambled code made from your computer’s network adapter address, computer name and processor type. The original values are never sent and can’t be recovered from the code.

We use these to confirm your license is valid and to enforce the number of devices it covers. We store only a scrambled form of your license key. If you buy a license, we also keep the email address and name you gave at checkout, encrypted, so we can send your key and help you recover it.

Discord direct messages (only if you connect)

When you click Connect Discord DM, Discord shares your Discord user ID and username with our relay service, which stores them along with the ID of the direct-message channel it uses to reach you. We keep this until you click Disconnect Discord. When an alert fires, Sentinel sends the product name, link, image, store and price to the relay, which passes it to Discord. The relay doesn’t store or log the message.

Alert channels you set up

Alerts sent to a Discord webhook go straight from your computer to Discord. If you configure other channels in Sentinel’s settings file (such as email, Telegram, ntfy, Pushover, Gotify, Slack or your own webhook), alerts go directly to those services. Their privacy policies apply.

Optional features that contact other services

• Testing a proxy asks api.ipify.org which address the proxy appears to come from.
• Free-proxy fallback, off by default, downloads lists of public proxies from third-party sites and sends store visits through proxies run by people we don’t know. Don’t turn it on if that concerns you.

What Sentinel never sends

No analytics, usage tracking, crash reports or advertising identifiers. Your product list, store logins and card details never reach us. You can see every request Sentinel makes on its Network page.

This website

sentineldrops.com uses no cookies, analytics or tracking. Our hosting provider keeps standard request logs, such as IP address, page and time, to run and protect the site. The site’s fonts load from Google Fonts, so Google receives your IP address when you visit. If you buy a license, payment is handled by Stripe on Stripe’s own pages. We never see your full card number.

Who we work with

We use a few companies to run Sentinel. They handle data only to provide their service to us:

We may share information if the law requires it, or to protect our rights or the safety of others. If Off By 1 is ever sold or merged, this information would transfer under this same policy.

How long we keep things

• Discord connection: until you disconnect.
• License records (scrambled key, device fingerprints, purchase email): for as long as your license exists, and afterward as long as we need them for accounting and legal reasons.
• Server request logs and backups: up to 90 days.

Your choices

• Delete everything on your computer: uninstall Sentinel and delete the data folder listed above. Remove any “Sentinel” entries from your keychain.
• Disconnect Discord: click Disconnect Discord in Settings. We delete your Discord link right away.
• See, correct or delete what we hold: contact us through offby1.tech. We’ll respond within 30 days. Depending on where you live, you may have legal rights to access, correct, delete or move your information. We honor these requests from anyone.

Everything else

Children. Sentinel isn’t meant for children under 13, and we don’t knowingly collect their information.

Where data is processed. Our servers are in the United States. If you use Sentinel from elsewhere, your information is processed there.

Security. We encrypt stored emails and names, keep only scrambled license keys, and keep sensitive details on your computer in its keychain. No system is perfectly secure, and we’ll tell affected users promptly if we learn of a breach.

Changes. If we change this policy, we’ll update the date at the top. For significant changes, we’ll also say so in the app’s update notes.

Contact. Off By 1 LLC, Washington, USA. offby1.tech