Kai, your on-device assistant

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Kai
KaiOn device

Today

  1. remind me to renew the domain before it lapses

    9:41 AM

  2. Set for the 3rd, 9am. I'll nudge you.

    9:41 AM

    On device

  3. what did it cost last year?

    9:42 AM

  4. £38.40. That was on the Namecheap invoice in your inbox, which isn't on this machine, so I asked Google for it.

    9:42 AM

    Cloud

  5. add that to the reminder

    9:43 AM

Message Kai… (: for emoji)

Auto

Local by default. Honest about the rest.

Kai runs on your machine, and says so on every message. When something has to leave, like a bigger model or your inbox, it says that on the message too.

Every reply says where it ran

A line under each answer: on device, or the name of the service it reached. On the message, not in a settings page.

On deviceCloud

Every Kai has a face

An avatar is a seed string, not an image. The generator ships inside the app, so a face costs no network call and nothing is stored. Same for the twenty-seven drifting past below. They were drawn when this page was built, and not one was fetched.

Change the seed, change the face.

Background work asks first

Only tools you mark background-readable run unattended. Anything that sends, deletes or changes waits for you.

Bring your own model

Already pay for Claude or GPT? Add the key in the app. It stays in your system keychain.

The model is a file you own

Not a request to a server. Not a queue. The weights sit in your app-data folder, and you can delete them.

Works with no account

Install it and start talking. No sign-in, no key, no network. That is the whole app for as long as you want it to be.

It nudges you

Reminders, memory and scheduling run on device, so they work with the wifi off.

What an account changes

Signing in changes what Kai can do. It never changes what Kai does with a local turn.

Doing whatSigned outSigned in
Chat with a local modelOn deviceOn device
Reminders, memory, schedulingOn deviceOn device
Transcript and attachmentsOn deviceOn device
Bigger hosted models—Leaves your device
Email and calendar—Optional provider access, approved separately
Your own provider keyLeaves your deviceLeaves your device

How linking works

Connect your account once, then choose the services the native app may use.

  1. Step 1

    Install and start talking

    Kai downloads a small model and runs it locally. No account, no key, no network.

  2. Step 2

    Choose a provider

    Sign in to Kai first. Then separately choose which email and calendar provider Kai may access.

  3. Step 3

    Link the app to your account

    The app shows a code and opens this site. You approve it, and from then on it can reach everything you connected.

  4. Step 4

    Kai talks to them directly

    The native app calls the provider directly with a short-lived access token; messages and events do not pass through Kai's gateway.

The questions
worth asking

Including the two we come off worst on. Leaving them out is how a page like this stops being worth reading.

  • Will the local model actually be any good?

    For reminders, memory, drafting and questions about your own stuff, yes. That is what Kai is for. For long reasoning, code, or anything needing knowledge of the world, a 4B model on your laptop loses to a hosted one, and there is no honest way to say otherwise. That is why you can point Kai at a bigger model, and why it tells you when it has.

  • What do I need to run it?

    About 4 GB of disk for the default model, and 8 GB of RAM. Apple silicon, a recent Windows machine or any Linux box will run it. Older hardware will run it slowly. The model is a file in your app-data folder, so if it is not worth the space, delete it.

  • If I connect Gmail, does my email pass through your servers?

    The native app calls Google directly with an expiring access token, so message and event contents are not routed through Kai's gateway.

  • What happens if you shut down?

    The app keeps working. Chat, reminders, memory and transcripts never needed us, so they carry on with no account and no network. You would lose the connected services, because holding those is the only thing an account does.

Still here? It costs nothing to try.

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