Your data is yours.
If you suspect that the app you use to send a message is doing more with your data than just sending it — you're right. Most of them are. Koaich is what changes when you decide your data is valuable enough to lock down.
You'd rather not have your day-to-day conversations sit in a database the platform can read.
Family logistics, medical updates, financial planning across spouses, the conversations that matter to you and shouldn't matter to anyone else. None of it needs to be in a tool whose business depends on being able to read it.
You think your data is valuable — and you'd rather you got the value, not the platform.
The data you create — what you talk about, who you talk to, what you care about, what you're planning — feeds a multi-billion-dollar advertising economy. None of that economy pays you. We don't use your data because we don't hold it readable. The math doesn't let us.
You suspect your messaging app is doing more than what's needed to actually deliver a message.
Delivering a message requires routing it from your phone to the recipient's. It does not require the platform to read it, store a readable copy, build a profile from the patterns, or tie it to your activity across other apps. Most messaging apps do all four anyway.
What "just sending a message" actually requires.
The technical minimum to route a message from your phone to someone else's is small: a recipient address, a delivery timestamp, an encrypted envelope of bytes. The recipient gets the envelope. Done.
Most of what your messaging app actually does is much more than that. Here's what most platforms keep readable, retained, and useful to them — none of which is needed to deliver your message.
A readable copy of the message itself. Stored indefinitely, often for the purpose of letting their AI features summarize it, their search index find it, or their support staff respond to a bug ticket. Not required to deliver.
Your full contact list, uploaded. Most messaging apps default to pulling your phone's address book into their servers — so they can show you "people you may know" and build a social graph. Not required to deliver.
Your patterns: who, when, how often, how long. Even if message content is encrypted, the social graph is signal. It feeds recommendation systems, advertising audiences, and the "people you may know" suggestions. Not required to deliver.
Cross-app linkage. Your messaging activity gets joined to your activity on the operator's other apps — Facebook, Instagram, LinkedIn, Search. Builds the ad-targeting profile they sell to advertisers. Not required to deliver.
Backups in cleartext. The convenience of restoring your message history on a new phone — by default, that history was stored somewhere the operator can read. End-to-end backups exist as opt-in on a few apps, but they aren't the default. Not required to deliver.
What changes when you hold the key.
Koaich was built backwards from the gap above. We start from what's actually needed to deliver a message — and stop there.
- · Read message content
- · Upload your full contact list
- · See who you message and when
- · Join messaging activity to your broader profile
- · Store cleartext backups by default
- · Use the data to power their advertising business
- · Hold ciphertext — we can't read content
- · Contact list encrypted on your device, never uploaded readable
- · Contact discovery via salted HMAC (we never see the email)
- · No advertising business; account isn't tied to a broader profile
- · Encrypted backups by default, not opt-in
- · Subscription-funded, so the math doesn't care about your data
The honest gap that's still on the roadmap: the address graph — who messages whom on routing — is still visible to our servers. Sealed-sender closes that gap and is being built. The day-1 launch posture is everything above plus sealed-sender shipping with the product.
People who've already thought, at least once, I shouldn't be putting this in this app.
- Family logistics— medical decisions about a parent, custody arrangements, immigration paperwork, financial planning across spouses. The stuff that sits in the family group chat that you wouldn't want indexed for ad targeting.
- Sensitive personal correspondence— therapy referrals, medical second opinions, financial advice from a friend who happens to be an accountant, candid discussions about work that you're not ready to make public.
- Photos that aren't for general circulation— kids, intimate moments, in-process creative work. Things you'd send to one person, not a platform that retains a readable copy.
- Professional outreach that's sensitive— salary negotiations, candidate strategy, leaving one job for another. Things you'd rather LinkedIn's recommendation system not have signal on.
- Anything you wouldn't volunteer to a market researcher. If you wouldn't hand it to a clipboard person on the street, it shouldn't sit in a database that funds itself by aggregating exactly that data.
Side-by-side with the apps you actually use: SMS, WhatsApp, Facebook Messenger, LinkedIn, Signal. Including the metadata rows that matter — business model, identity coupling, contact-list visibility, sealed-sender.
Compare Koaich to your messaging apps →Your data, your rules.
Get on the Koaich waitlist. Invites going out in waves.