Caty — Private messenger you host yourself

01 · The problem

Everyone promises privacy.
Nobody can prove it.

Signal

Claims to store nothing. Servers are in the US. A 2022 Twilio breach exposed that data you didn't know existed could be collected anyway. You're trusting them — not math.

End-to-end encryption of content, yes. But Meta openly admits storing the metadata — who, when, where, how often. That's 90% of what anyone actually needs to profile your life.

Closed-source servers. End-to-end encryption only in "Secret Chats" — one-on-one, on one device. Your groups, channels, and regular chats sit on their servers in readable form. Whoever controls those servers controls your history.

You have to trust someone with your private conversations.
Why not yourself?

02 · How Caty is different

You're not our user.
You're your own host.

Buy the client once. Set up your own server in 30 to 60 minutes with our AI concierge. Talk to whoever you want. We don't see your messages. We don't even know your server exists.

01

Your domain

From $1/year at any registrar. Your Caty ID becomes simply @you — short, clean, yours.

02

Your server

From $10/month for chat. $20-30/month if you want voice and video calls. Pick the country, pick the provider. We never see it.

03

Our AI concierge

Walks you through setup in plain language. If you get stuck, the agent can take over and finish for you.

04

Yours, forever

We have no access, no backdoor, no way in. If we disappear tomorrow, you don't notice.

05

Proven cryptography

We didn't invent the encryption — we packaged it. Caty runs on Matrix protocol with Olm/Megolm — the same stack used by Bundeswehr, French government, and NATO. Audited by NCC Group and Least Authority.

03 · How it works

Built with you, not for you.

Buy a domain and a server in your own name. Our AI walks you through the setup — command by command, in plain language. In well under an hour, you sign in to your own messenger and start writing.

root@caty-server: ~ ×

+ ▾

− □ ×

Caty AI

Get domain
Buy a server
AI sets it up
Install the app
Start messaging

Caty in your stack

How many messengers do you already have?
Add the one that's actually yours.

Look at your phone. WhatsApp. Telegram. Signal. iMessage. Maybe Viber, Line, WeChat, or that new app a friend insisted on. Most people carry 5 to 12 messengers — switching between them all day. None of them are yours.

Caty isn't trying to replace any of them. Caty is the messenger you set up for the conversations that have to stay yours — your team, your family, your clients, your deals, your sources. The ones that, if leaked, change your life.

You buy once. You install your server. You invite people you trust — they download the client free, register on your server free, and the only place those messages exist is on a server you control. No mass adoption needed. No "but my friends aren't on it" problem. Your circle. Your infrastructure. Done.

You're not promoting Caty. You're promoting yourself as someone whose conversations don't leak. The most expensive thing you can give the people who matter is privacy by default.

04 · Get Caty

Founding access.
First 1,000 customers only.

Founding access

€99 €49

One-time payment. No subscription. Yours forever.

Caty for Android — live on Google Play
Caty for iOS — free for you when released
AI assistant guides you through server setup (50 messages or 14 days)
One year of updates included
End-to-end encrypted — your server, your keys
Duress PIN — wipe everything if forced to unlock
Caty client (AGPL) — duress PIN, simplified UX, optimized for self-hosting. Built on Element X.

Get Caty for €49 →

30-day money-back guarantee · Pay by card or Apple Pay · No recurring charges

After the first 1,000 customers, regular price is €99. Higher tiers with full source code and managed setup will be available soon.

05 · Who it's for

If any of this sounds like you — Caty was built for you.

Lawyers

Client confidentiality as a professional requirement. Not a marketing claim.

Investigative journalists

Protecting sources in places where press freedom isn't guaranteed. No trail, no leaks.

Family offices

Sensitive wealth and investment discussions that never should appear anywhere else.

Crypto teams

Coordinating without leaks. Keys and conversations under your own roof.

Human rights defenders

Working in authoritarian regimes where communication itself can be a crime.

Everyone tired of Big Tech

You don't have to be a target to want the mail in your house to stay in your house.

06 · Features that actually matter

Not a feature list. A point of view.

Open-source client (AGPL)

Caty is a fork of Element X under AGPL — fully open-source. Read every line, build it yourself, fork it. No "trust us" required — we give you the tools to verify what's running on your phone.

Duress PIN

Enter your real PIN twice — you're in. Enter a fake PIN twice — everything wipes. Device and server. No one can prove there was anything there.

AI assistant

Walks you through setup step by step in plain language. Generates the commands, explains what they do, helps when something doesn't work. Get your server up and running in well under an hour, even without prior server experience.

Your server, anywhere

You pick where your server lives. We don't. Your messages aren't in our data center, in our country, under our jurisdiction.

Audited cryptography

Olm/Megolm — the encryption protocols Caty uses — were independently audited by NCC Group (2016) and Least Authority (2020). The same encryption protects messaging for the Bundeswehr, French government, and NATO. We didn't invent it. We packaged it.

Server runs Synapse

Your server runs Synapse — the reference Matrix homeserver from the Matrix Foundation, licensed Apache 2.0. We don't add closed binaries. The configs are plain text, you can read every one. Even if Catyonic disappears, your server keeps running.

07 · Why we don't ask for trust

Every privacy product tells you "trust us, we're different."

We won't. We've been there — built products, signed NDAs, watched companies get acquired, seen promises broken. The only privacy that survives is the privacy you control yourself.

So we didn't reinvent encryption. Matrix did, in 2014. It's been audited, deployed by armies, and runs on millions of devices. We didn't reinvent the client. Element X did, and we forked it under AGPL — every line readable, every line yours.

What we built is the bridge. The 60-minute setup. The AI that explains every command. The license you pay for once. The mobile app with duress PIN. The promise that if Catyonic disappears tomorrow, your server keeps running — because it's not ours, it's yours. Built on Synapse, an open Matrix server. No closed binaries on your side.

We're not asking you to trust us. We're giving you the tools to never need to.

08 · Research

We also publish what we find.
Quarterly. Free. With sources.

Privacy claims are everywhere. Verifiable facts are rare. Every quarter we publish a snapshot of the messaging industry — pulled from privacy policies, transparency reports, court records, and peer-reviewed research. No editorial. No ranking. Just what the platforms themselves disclose.

Latest issue · 2026 Q2 · Apr 27

Messenger Privacy Report

Twenty platforms. Twenty-four months. Forty-nine verified events. Four hundred seventy-eight primary sources.

20 platforms 49 events 478 sources

Read the report →

09 · Frequently asked

Questions we get most.

What protocol does Caty use?

Matrix, with end-to-end encryption via Olm and Megolm — the same protocols used by Element, the Bundeswehr, the French government's Tchap, and NATO unclassified communications. They've been independently audited (NCC Group 2016, Least Authority 2020) and have been deployed at scale for over a decade. We didn't invent the cryptography. We packaged it so you don't have to be a developer to run it.

Is Caty open-source?

The Caty mobile client is a fork of Element X under AGPL — fully open-source. You can read the code, build it yourself, fork it. The server runs Synapse from the Matrix Foundation, licensed Apache 2.0 — also open-source, no closed binaries from us. Our proprietary work is the wrapping: deployment scripts, the AI onboarding assistant, our visual identity. The cryptography and the client you use every day are open and verifiable.

Why pay €49 if Matrix is free?

Matrix is a protocol — like SMTP for email. You can run it yourself for free, and we encourage you to: install Synapse on a VPS, build Element X from source, configure certificates, set up TURN, learn the federation model, debug for three days. Or you pay €49 once, get our pre-built mobile app with extra features (duress PIN, simplified UX, AI onboarding), and run it in an hour. It's like Vercel and Next.js — the framework is free, the platform makes it easy. Same model.

I'm hosting Caty for my family — am I a telecom operator?

No. Self-hosting a messenger for yourself, your family, and your invited circle is private use — the same legal category as running a personal email server, a Nextcloud, or a home VPN. You're not offering a public service, you're not collecting subscribers, you're not handling third-party traffic commercially. In every jurisdiction where running a personal email server is legal, running Caty is legal. If you want to offer Caty as a public commercial service to strangers, that's a different setup — talk to a lawyer first.

What do I need to get started?

An Android phone (or wait for iOS). A VPS — chat-only fits in $10/month, voice and video calls need closer to $20-30/month. A domain name — from $1/year. The AI assistant guides you through obtaining both during setup. No prior server experience required.

What about iOS?

Android is available now on Google Play. iOS is in development and will be released as a free update for everyone who buys Caty now — no extra charge, no waiting. We don't announce a specific date because it depends on Apple's review timeline, but it's coming.

What does "founding access" actually mean?

The first 1,000 customers get Caty for €49 instead of €99. Same product, lower price — our way of thanking the people who trusted us early. After 1,000 customers, the price moves to €99 permanently.

What if it doesn't work for me?

30-day money-back guarantee. No questions asked. If you can't get your server running, or you simply don't like it, email us within 30 days and we refund in full.

How is this different from Signal or Telegram?

Signal stores nothing on your behalf — but you trust their servers, in their country. Telegram only encrypts "Secret Chats" end-to-end; everything else lives readable on their servers. Caty puts the server in your hands. Your messages live where you decide. Your encryption keys live on your devices. We never see anything.

Is this legal where I live?

Privacy software is legal in virtually all democratic jurisdictions — the EU, UK, US, Switzerland, and most of Asia and Latin America. We're registered in the EU as a software company. What you buy is a software license — same legal category as Microsoft Word or Photoshop.

What happens if your company disappears?

Your server keeps running. Your client keeps working. You own your data, forever. We're not in your infrastructure. Our disappearance doesn't affect you at all — which is exactly the point.

Can I use my own domain name?

Yes. In fact, you should — your domain is part of your identity. Your Caty ID will simply be @you, bound to your own domain under the hood. You pick the domain. We never see it.

Do you support group chats, voice, and video?

Yes — the same as Signal or Telegram. But all running on your server, with your keys.

How do I pay?

Card or Apple Pay through Stripe. We never see your card details — they go directly to Stripe, same payment processor used by Substack, Notion, Linear and most of the modern web. One-time payment — no recurring charges.

How often are there updates?

Major releases ship one to two times per year. Minor updates and security patches — continuously, automatically, free for the first year. After year one, an optional €49 keeps your client up to date for the next year.

10 · Get started

Ready to own your messenger?

One payment. One server. One messenger that nobody can shut down, seize, or hand over. Not even us.

€99 €49 Founding access · first 1,000 only