ProseMirror Compose

A Kotlin Multiplatform rich-text editor library for Compose Multiplatform, built on ProseMirror through its Kotlin port (com.atlassian.prosemirror).

The ProseMirror document model is the single source of truth — Compose renders a flattened projection of the immutable tree, and every edit flows back through a diff → transaction pipeline.

Platforms: Android · Desktop (JVM) · iOS · Web (scaffolding only)

• ProseMirror document model — immutable Node tree as source of truth, with AnnotatedString + span styles as the flat rendering projection
• Formatting — bold, italic, underline, strikethrough, inline code, links, headings, text color/size; collapsed-selection staging (type, then format)
• Lists — bullet and ordered lists with wrap / lift / split, Enter/Tab handling, indent gutters, ordered numbers derived at render time
• Undo / redo via the ProseMirror history plugin
• HTML clipboard — copy and paste rich HTML through the ProseMirror Slice pipeline
• Markdown import / export — setMarkdown, insertMarkdown, toMarkdown (JetBrains markdown/GFM parser → HTML → ProseMirror DOM parser)
• Trigger system — @mention-style triggers with token nodes inserted into the document
• Inline images as atomic nodes, loaded via a pluggable ImageLoader
• Material 3 components — ProseMirrorEditor (filled), OutlinedProseMirrorEditor, read-only ProseMirrorText, expandable variants
• Stability markers — @ExperimentalProseMirrorApi / @InternalProseMirrorApi on the public API surface

Following the recommended Kotlin Multiplatform structure:

androidApp ─┐
desktopApp ─┼──▶ composeApp ──▶ prosemirror-compose
iosApp ─────┘
webApp ──────┘   (once web targets are enabled)

prosemirror-compose-coil3 ──▶ prosemirror-compose

The editor keeps an immutable ProseMirror document tree as its state of truth. Compose never renders the tree directly:

• ProseMirrorState holds the PMEditorState, the derived flat AnnotatedString, and the BasicTextField state.
• PositionCoordinateMap maps between ProseMirror structural positions and flat Compose text indices, in both directions.
• Typing goes TextField → diff → ProseMirror Transaction → plugins/steps → rebuilt AnnotatedString; selection moves and IME composition take the inverse path.

See CLAUDE.md for the full detail on the edit pipeline and its invariants.

androidApp, desktopApp, iosApp and webApp all run the same demo App() composable from composeApp, ported from the upstream compose-rich-editor sample: Home, rich editor, HTML editor, Markdown editor, Slack, Mentions, Undo/Redo, Lists config, real examples, Links, Images, GitHub, Notion, Headings, Claude, and Expandable text.

Requirements: JDK 17+, Android SDK (Android targets only).

# Android debug APK
./gradlew :androidApp:assembleDebug

# Desktop app
./gradlew :desktopApp:run             # standard run
./gradlew :desktopApp:hotRun --auto   # hot reload

# Web (placeholder UI only)
./gradlew :webApp:wasmJsBrowserDevelopmentRun
./gradlew :webApp:jsBrowserDevelopmentRun

# iOS — open iosApp/ in Xcode and run from there (iOS targets build on macOS only)

Tests:

./gradlew :prosemirror-compose:jvmTest               # primary suite (Desktop/JVM)
./gradlew :prosemirror-compose:testAndroidHostTest   # Android host
./gradlew :prosemirror-compose:iosSimulatorArm64Test # iOS simulator (macOS only)

The library modules are published to Maven Central under the io.github.woods-marshes group:

// In a Kotlin Multiplatform commonMain source set
dependencies {
    implementation("io.github.woods-marshes:prosemirror-compose:0.1.0")
    implementation("io.github.woods-marshes:prosemirror-compose-coil3:0.1.0") // optional Coil3 images
}

Gradle module metadata is published for the kotlinMultiplatform artifact, so Android / JVM / iOS variants are resolved automatically from the same coordinates.

Publishing is driven by GitHub Actions through the Maven Central Portal:

• Push to main → publishes 0.1.0-SNAPSHOT to the Central Portal snapshot repository.
• Push a v* tag (for example v0.1.0) → uploads 0.1.0 to the Central Portal and automatically publishes it after validation.

Required GitHub Actions secrets:

Local publishing for smoke-testing:

./gradlew :prosemirror-compose:publishToMavenLocal :prosemirror-compose-coil3:publishToMavenLocal

Apache License 2.0 — see LICENSE.

This project is adapted from compose-rich-editor (Apache-2.0, © Mohamed Rejeb) and builds on the Kotlin port of ProseMirror, prosemirror-kotlin / com.atlassian.prosemirror:* (v1.1.20, Apache-2.0, © Atlassian Pty Ltd). The editor is re-packaged under com.github.wood.prosemirror.compose.