> 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/readme.md).

# January Developer Platform

Build food search, food analysis, meal, water, and weight logging, and glucose prediction into your product with January.

## Get started

* [**Documentation**](/docs/overview.md): the platform, how authentication works, and what you can build.
* [**Quickstart**](/docs/quickstart.md): your first REST API request in a few minutes.
* [**REST API reference**](/rest-api/api-overview.md): every endpoint, request field, and response.
* [**iOS SDK**](/client-sdks/ios-sdk/overview.md): Swift package and native food scanner.
* [**Android SDK**](/client-sdks/android-sdk/overview.md): Kotlin SDK and Compose food scanner.
* [**React Native SDK**](/client-sdks/react-native-sdk/overview.md): TypeScript API backed by the native iOS and Android SDKs.
* [**Web SDK**](/client-sdks/web-sdk/overview.md): TypeScript browser SDK and React example.

## Authentication boundary

Your backend authenticates with an `sk-…` API key. Apps never ship that key: your backend uses it to mint a short-lived `ct-…` client token for the signed-in end user, and the app calls January with that token. See [How authentication works](/docs/authentication.md).

Create and manage keys in the [January Developer Dashboard](https://dashboard.january.ai).