Polariton Try the prompt

An AI computer in your pocket

Polariton is an AI coding agent for Android. It builds apps, sites and scripts on your phone, and does tasks for you, with your own AI tokens. Everything runs on the phone, where you can watch it.

Watch it build Try the prompt

7-day free trial, no credit card. Sign in with Google. Android 8 or newer, sideloaded APK.

9:415G
your-model

What shall we build?

Make an app, a site or a script. It runs on this phone.

    Working

    Watch every step it takes

    The work stays on screen: a road of steps, a diff for every change, and the app it is testing. The little one hops along as each step finishes.

    Ask in plain words

    Say what you want the way you would tell a friend. Drop in a screenshot, a file or a voice note if that is easier.

    Make a snake game I can play on my phone

    It plans before it types

    The plan becomes the road. Each item is a stop, so you always know where it is and what comes next.

    • Create an Expo project
    • Draw the board and the snake
    • Add swipe controls
    • Keep score between games

    Every change is a diff

    Read exactly what changed in each file. Accept it, ask for a fix, or step back to any earlier point.

    App.tsx
-  const speed = 200;
+  const speed = Math.max(80, 200 - score * 6);
+  useSwipe(dir => setHeading(dir));

    It checks its own work

    With Shizuku, the agent opens your app in Expo Go, takes a screenshot, reads the screen and the logs, and taps through it after every edit.

    screenshot  1080 × 2400, board visible
ui_tree     Score: 0, Restart button found
tap         swipe right, snake turned
logcat      no errors

    You get a working app

    It runs on the phone in your hand. Keep chatting to change it, or switch on Show code and edit it yourself.

    Build real apps on your phone

    Expo apps with a live preview, full-stack sites on localhost and Python scripts, each in its own folder. No laptop. Flip one switch to see the code behind the result.

    Snake game
    Running in Expo Go Score 7. Swipe to turn. The preview reloads by itself after each change. 
    export default function App() {
  const [snake, setSnake] = useState(START);
  const speed = Math.max(80, 200 - score * 6);
  useSwipe(dir => setHeading(dir));
  useInterval(step, speed);
  return <Board snake={snake} food={food} />;
}
    › npx expo start
Metro waiting on exp://127.0.0.1:8081

    • Expo apps

      Metro runs on the phone and your app opens in Expo Go. No APK build, no laptop.

    • Websites

      Full-stack sites served on localhost, with a built-in browser to try them.

    • Python scripts

      Run a script with one tap and read its output right next to the chat.

    Hand anything to the Assistant

    It works on the web, in your files and on your phone, once or on a schedule. It shows you the screen it controls and stops to ask before anything that matters.

    • Answer the support chat on this site and tell me what they say
    • Rename last week's screenshots by what is in them
    • Check this page every morning and tell me if the price drops

    Open this page?

    The Assistant wants to visit a site it has not used before.

    https://shop.example.com/kettle

    Nothing happens until you choose.

    Bring your own tokens

    Bring your own API keys. Point Polariton at the provider you already pay for, or run your own model router on the phone. Pick the coding agent you like.

    OpenCodeDefaultThe agent loop for Build and the Assistant, talking to your local router.
    Claude CodeOptionalDownloaded on first run. Uses your own Anthropic API key.
    CodexOptionalOpenAI's coding agent as a third harness, on your own key.
    9routerOn deviceAn open-source AI gateway on port 20128. Add any provider key once and every agent can use it.
    ANTHROPIC_BASE_URL=http://127.0.0.1:20128

    A real Linux box inside

    Linux on Android, without root: a Debian arm64 userland runs in the app through proot. No root, no cloud machine, and your files never leave the phone.

    polariton:~/snake$ uname -m
aarch64
polariton:~/snake$ node -v && python3 -V
v22.12.0
Python 3.12.8
polariton:~/snake$ cat assets/board.png | wc -c
48213
    Drag a file from the panel into the terminal or the prompt

    One folder per conversationEvery chat, task and build keeps its own files, so nothing gets mixed up.

    Native, not a web pageThe editor, terminal and file panel are Android views made for thumbs.

    Works while you sleepLong jobs keep going in a foreground service and report back when done.

    Questions, answered

    The short version of what people ask before they install.

    Can I build an Android app on my phone without a computer?

    Yes. Polariton runs Metro on the phone and opens your Expo app in Expo Go, so there is no laptop and no APK build. It also builds full-stack websites on localhost and Python scripts.

    Which AI coding agents and models does Polariton use?

    OpenCode is the default agent. Claude Code and Codex are optional. All of them talk to your own provider through 9router, an open-source AI gateway that runs on the phone, so you bring your own API keys.

    Do I need to root my phone?

    No. Polariton runs a Debian arm64 Linux userland inside the app through proot. No root and no cloud machine. You need Android 8 or newer.

    How much does Polariton cost?

    Polariton starts with a 7-day free trial. No credit card is needed; you sign in with Google. You pay your AI provider directly for the tokens you use.

    Is Polariton on Google Play?

    Not yet. Polariton is in internal testing and is installed by sideloading the APK while signing and verification are finished.

    Do my files leave the phone?

    Your projects and files stay on the phone. Only the prompts and code context the agent sends go to the AI provider you chose.