Privacy
Last updated 4 November 2026.
This page covers both the desktop app and the website, periskopos.com.
The short version
Section titled “The short version”- The app sends nothing anywhere unless you ask it to. No telemetry, no account, and your keys stay on your computer.
- The site has no analytics, no tracking, no ads, and no cookies of ours.
- If you join the Watchtower waitlist, we keep your email address to send you one email when Watchtower opens, and nothing else. Ask, and it’s deleted.
- Nothing is sold or shared for marketing.
Who we are
Section titled “Who we are”Periskopos is made by Daniel Noam Tuby, who decides what happens to the information on this page. Write to hello@periskopos.com about anything here.
The desktop app
Section titled “The desktop app”This program will not transfer any information to other networked systems unless specifically requested by the user or the person installing or operating it. We never receive anything from it: there’s no server of ours for it to talk to. What that means in practice:
- What you connect. Periskopos talks to the providers whose keys you add (GitHub, Cloudflare, Vercel and the others), to the sites and domains you ask it to check, to the domain registry’s public lookup (RDAP) for an expiry date, and to the public status pages of the providers you use. It goes to each of them directly, from your computer, and only to read what you asked it to watch, or to run an action you approved.
- Alerts you turn on. Phone alerts go to the service you choose (ntfy, Telegram or email through Resend) only after you set it up, and are off until then.
- Updates. The installed app asks GitHub Releases whether there’s a new version, 30 seconds after it starts and every 6 hours, and downloads it from there. GitHub sees what any download shows it (your IP address, the app’s version and system) and nothing about your apps or accounts. Running Periskopos from its source instead of the installer checks nothing.
- Whether you’re online. When a site you watch gives no answer, and every 30 seconds while you’re offline, the app sends a bare HEAD request to github.com and www.cloudflare.com, so your dropped Wi-Fi isn’t reported as an outage. They see what any request shows them (your IP address) and nothing about your apps or accounts.
- Nothing else. No telemetry, no analytics, no crash reports sent anywhere, and no account. The bug button, or Help → Report an issue, copies diagnostics for you to read and paste into GitHub yourself; nothing is sent for you. They include how the World has run on your computer (frame times and your graphics card), never your apps’ names or addresses.
Your keys stay in a file on your computer, encrypted in the installed app (where it is). Each provider’s own privacy policy covers what it does with the requests your keys make.
Visiting the site
Section titled “Visiting the site”The pages are served by Cloudflare. Like any web host, it sees each request (your IP address, your browser, the page asked for) to deliver the page and keep the site safe from attacks. It keeps logs for that under its own policy; we can see traffic totals in its dashboard, not who you are.
The site loads nothing from anyone else: fonts, images and scripts all come from periskopos.com, and its security policy wouldn’t let a tracking script run if one were added.
Cookies and storage. We set no cookies. Cloudflare may set a strictly necessary security cookie if it suspects an attack. Your browser remembers whether you chose the light or dark theme (in its local storage, on your device only); clear it any time.
The Watchtower waitlist
Section titled “The Watchtower waitlist”If you leave your email on the Watchtower page, we keep:
- your email address,
- when you joined,
- which page the form was on.
Why: to email you once, when Watchtower opens. You asked for that by joining, and you can change your mind at any time.
Where: in a database at Cloudflare (D1), in our own account. Only we can read it.
How long: until that email has gone out, then the list is deleted. Sooner if you ask.
Mail to that address is forwarded by Cloudflare to an inbox at Google (Gmail). We keep it as long as it’s useful to answer you, and delete it on request.
Links to other sites
Section titled “Links to other sites”Downloads, the source code and Discussions are on GitHub, which handles what you do there under its own privacy statement. The same goes for any other site we link to.
Your rights
Section titled “Your rights”You can ask what we hold about you, have it corrected, or have it deleted: write to hello@periskopos.com and we’ll answer within 30 days. If you think we’ve got something wrong, you can also complain to your data protection authority (in Israel, the Privacy Protection Authority; in the EU and UK, your country’s).
Cloudflare and Google are US companies, so what they store may be held outside your country, under their own safeguards for that.
Changes
Section titled “Changes”If this page changes, the date at the top changes with it. If we ever want to use your address for something new, we’ll ask you first.