> For the complete documentation index, see [llms.txt](https://docs.january.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.january.ai/client-sdks/android-sdk/getting-started/example-app.md).

# Example app

The `demo` module of the [January Android SDK repository](https://github.com/January-ai/january-sdk-android) is a Jetpack Compose app that uses every resource: food search with full foods and servings, food analysis and the native scanner, restaurants, food logs, a Tracking tab with each day's food, water, and weight and week, month, and year charts, glucose prediction, and user and timezone settings. It creates a new client whenever you switch users, as [Client lifecycle](/client-sdks/android-sdk/concepts/client-lifecycle.md) describes.

Open the repository in Android Studio, or set `ANDROID_HOME` for command-line builds.

## 1. Start the token relay

The demo gets its tokens from the [token relay](/docs/authentication.md#develop-with-the-token-relay). Starting it walks you through creating an API key and switching on **Enable client tokens** in the Developer Dashboard. The key stays in the relay's `.env` file and never enters the app.

## 2. Point the demo at the relay

Add the relay's values to the repository's `local.properties`, which is untracked. Never commit it.

| Where the relay runs                                                                                 | `january.partnerTokenUrl`                       | `january.partnerSessionToken` |
| ---------------------------------------------------------------------------------------------------- | ----------------------------------------------- | ----------------------------- |
| This computer, used from the emulator                                                                | `http://10.0.2.2:8787/api/january/client-token` | Leave it out                  |
| Your Wi-Fi, used from a device (`HOST=0.0.0.0 ./start.sh`)                                           | The Wi-Fi URL the relay prints                  | The token the relay generates |
| Hosted ([Vercel guide](https://github.com/January-ai/january-token-relay#optional-deploy-to-vercel)) | The relay's HTTPS token URL                     | Its `RELAY_TOKEN`             |

```properties
january.partnerTokenUrl=http://10.0.2.2:8787/api/january/client-token
```

The demo sends a `POST` with the selected end-user ID in `January-End-User-ID`, plus `Authorization: Bearer <january.partnerSessionToken>` when that is set. Its debug build allows cleartext traffic, so the local `http://` URL works.

## 3. Build and run

```bash
./gradlew :demo:installDebug
```

Search for a food, open it, change its serving, and try the scanner. If the token URL is missing, the demo says so instead of choosing a default.

## Without the relay

For the quickest local test, leave out the token values and set `january.apiKey=sk-…` in `local.properties`. Debug builds use the key directly and show a warning. Never commit the key, share the APK, or distribute the build.

Next: [Client lifecycle](/client-sdks/android-sdk/concepts/client-lifecycle.md)