# Crease

> Hinge angle, fold position and fold-aware layouts for Compose Multiplatform, on Android foldables and iPhone Duo.

## Docs

- [Introduction](https://crease-black.vercel.app/): Kotlin Multiplatform library for the hinge angle, fold position and fold-aware layouts in Compose Multiplatform, on Android foldables and iPhone Duo.
- [Getting started](https://crease-black.vercel.app/getting-started): Add Crease to a Compose Multiplatform project and read the fold state.
- [Examples](https://crease-black.vercel.app/examples): Two sample apps and a web demo that show Crease in use.
- [Why Crease](https://crease-black.vercel.app/prior-art): What exists for foldables and the iPhone Duo today, and the gap Crease fills.
- [Changelog](https://crease-black.vercel.app/changelog): Every release of Crease, newest first.

## Guides

- [Postures and the hinge](https://crease-black.vercel.app/guides/postures-and-hinge): Use the hinge angle for effects and the posture for layout.
- [Two-pane layouts](https://crease-black.vercel.app/guides/two-pane-layouts): Split content at the fold with FoldAwareTwoPane, and choose what happens on a device without one.
- [Tabletop mode](https://crease-black.vercel.app/guides/tabletop-mode): Put content above the fold and controls below it with TabletopLayout.
- [Avoiding the fold](https://crease-black.vercel.app/guides/avoiding-the-fold): Keep one element on one side of a separating fold with Modifier.avoidFold().
- [Observing the fold](https://crease-black.vercel.app/guides/observing-the-fold): Read the fold state in a view-model with rememberFoldStateFlow, react to posture changes, and animate between postures.
- [Previews and tests](https://crease-black.vercel.app/guides/previews-and-tests): Pretend to be any foldable with ProvideFoldState and the FoldState factories.
- [Cover display](https://crease-black.vercel.app/guides/cover-display): Show a composable on the outer display of a foldable with the crease-cover module, and what each platform needs for it.
- [iPhone Duo](https://crease-black.vercel.app/guides/iphone-duo): What Crease needs on iOS, how the data maps, and how to test with the Xcode simulator.
- [Android](https://crease-black.vercel.app/guides/android): How Crease reads folds and the hinge angle on Android, and how to test on an emulator.
- [Troubleshooting](https://crease-black.vercel.app/guides/troubleshooting): Common problems and what causes them.

## Reference

- [Types](https://crease-black.vercel.app/reference/types): HingeStatus, Hinge, FoldOrientation, Fold, Posture, FoldState and TwoPaneFallback.
- [Composables and modifiers](https://crease-black.vercel.app/reference/composables): rememberFoldState, rememberHinge, rememberFoldStateFlow, rememberPostureTransition, ProvideFoldState, FoldAwareTwoPane, TabletopLayout and Modifier.avoidFold.

## Agent skills

- [crease](https://crease-black.vercel.app/.well-known/agent-skills/crease/SKILL.md): Read the Crease docs instead of answering from memory. Hinge angle, fold position and fold-aware layouts for Compose Multiplatform, on Android foldables and iPhone Duo. Use when a task involves Crease: how it works, how to set it up or configure it, or its API.

## Agent resources

- [llms-full.txt](https://crease-black.vercel.app/llms-full.txt): The full Markdown of every page in one file.
- [Page Markdown](https://crease-black.vercel.app/index.md): Append `.md` to any page URL to fetch that page as raw Markdown.
- [JSON API](https://crease-black.vercel.app/api/docs/pages.json): Page index of the JSON docs API; each entry links the page's JSON and Markdown forms. Described by the OpenAPI document at https://crease-black.vercel.app/openapi.json.
- [Agent skills](https://crease-black.vercel.app/.well-known/agent-skills/index.json): Agent Skills discovery index of the skills this site publishes.
- [API catalog](https://crease-black.vercel.app/.well-known/api-catalog): RFC 9727 linkset of the APIs documented here.
- [AI catalog](https://crease-black.vercel.app/.well-known/ai-catalog.json): ARD manifest of the agent-facing resources on this site (MCP server, skills, APIs).
- [agent-readability.json](https://crease-black.vercel.app/agent-readability.json): Manifest of every agent-facing artifact on this site.
- [Sitemap](https://crease-black.vercel.app/sitemap.xml): Every indexable page URL with its last-modified date.