Ask what you can't ask the cloud.
Bastion is AI chat that runs entirely on your iPhone. No server, no account, no logs — nothing exists to leak, breach, or subpoena. You hold your messenger to that standard. Your AI should meet it too.
No server · No account · No logs · Works offline · Free
Built for people with sources to protect.
Journalists working a story. Dissidents under surveillance. Lawyers, investigators, clinicians — anyone whose thinking carries a duty of confidentiality. The most revealing thing about you is what you ask. A cloud chatbot keeps that question on someone else's computer, tied to your account, governed by someone else's policy.
Bastion takes the other path — the one Signal proved: make the private thing the default thing, and make it just as good. The model runs on your iPhone's own silicon. The conversation is stored in your iPhone's encrypted storage. There is no second copy, no account linking you to a question, and no company that could comply with a request for your chats, because nothing exists to hand over.
We can't read your conversations. Can't — not won't.
No server to subpoena
There is no Bastion backend to breach, log, or compel. Your words are processed by your phone and go nowhere else.
No identity attached
You never sign in. Nothing links you to what you ask — there's no account to tie a question to.
Open models, your hardware
Apple Intelligence, or open-weight models you can look up — not a black-box API. Run locally with MLX.
Documents stay sensitive
Attach photos, PDFs, or files. Text extraction and OCR run on-device — question a leaked document without uploading it anywhere.
Works at 35,000 feet
No server means no dependency on the internet existing. Flights, field work, dead zones, hostile networks — download once, works everywhere.
Wipeable by design
Delete a chat, a model, or the app — everything it knew goes with it. Models free their gigabytes back in one tap.
Turn on airplane mode. Bastion keeps working.
Every claim on this page reduces to one you can verify in five seconds: cut the network entirely, and nothing changes. That's what "no server" means.
Honest limits, because you need them.
On-device models are smaller than data-center ones — capable for real writing and thinking, but they will sometimes be wrong; treat them like a sharp colleague, not an oracle. Your chats are exactly as safe as your iPhone: protected by its passcode and hardware encryption, existing nowhere else — Bastion cannot protect a device that's unlocked in someone else's hands. The AI reads text in images; it doesn't describe pictures. English interface for now. Free, no ads, no subscription — and this website has no cookies, no analytics, and no JavaScript.