A Compose Multiplatform code editor with VS Code's keys and Monaco's API shape: multiple cursors, incremental highlighting, folding, find and replace, diagnostics, completions, a minimap and sticky scroll. It runs on Android, desktop (JVM) and the browser (Wasm) from one codebase, and draws only the lines on screen, so a keystroke costs the same in a 5,000-line file as in a 50-line one.

Upgrading from 0.5? 0.6 replaces the text field underneath the editor, and the API changes with it. docs/MIGRATION_0.6.md has every change with a before and after.

Aardink publishes four artifacts on Maven Central:

• com.aardarch:aardink — the editor library: composables, state, theming, and the language-service interfaces.
• com.aardarch:aardink-languages — built-in language definitions (Kotlin, TypeScript, JSON, TOML, XML, HTML, CSS, Markdown, plain text).
• com.aardarch:aardink-languages-lsp — a bridge to an external Language Server over JSON-RPC (stream transport on JVM/Android, WebSocket in the browser).
• com.aardarch:aardink-editor-web — browser only: mounts the editor into a DOM element behind a small JavaScript-friendly API. See Using Aardink in a web app.

and one package on npm, @aardarch/aardink-web: the ready-built browser editor for any JavaScript app, with the same version number.

The editor module is intentionally language-agnostic. Pull in aardink-languages for the bundled definitions, or implement your own via LanguageDefinition + LanguageRegistry.

Each is a Kotlin Multiplatform publication: a Gradle Module Metadata root plus one artifact per target. Declaring com.aardarch:aardink resolves to aardink-android, aardink-jvm or aardink-wasm-js automatically, the same way kotlinx.coroutines works — you do not name the target yourself.

Kotlin with Compose Multiplatform (Material 3) on every target.

// settings.gradle.kts
dependencyResolutionManagement {
    repositories {
        mavenCentral()
    }
}

// app/build.gradle.kts
dependencies {
    // Use the current version from the Maven Central badge above.
    implementation("com.aardarch:aardink:<version>")
    implementation("com.aardarch:aardink-languages:<version>")
}

import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import com.aardarch.aardink.core.rememberCodeEditorState
import com.aardarch.aardink.languages.LanguageRegistry
import com.aardarch.aardink.ui.CodeEditorLayout
import com.aardarch.aardink.ui.EditorOptions
import com.aardarch.aardink.ui.EditorThemes
import com.aardarch.aardink.ui.LocalEditorTheme

@Composable
fun MyEditor() {
    val kotlinLanguage = LanguageRegistry.withBuiltIns().byId("kotlin")!!
    val state = rememberCodeEditorState(
        initialText = "fun main() = println(\"Hello, Aardink\")",
        tokenizer = kotlinLanguage.tokenizer,
    )

    CompositionLocalProvider(LocalEditorTheme provides EditorThemes.VsCodeDark) {
        CodeEditorLayout(
            state = state,
            languageService = kotlinLanguage.languageService,
            foldingProvider = kotlinLanguage.foldingProvider,
            options = EditorOptions(showMinimap = true, stickyScroll = true),
        )
    }
}

With a language service and no diagnostics argument, the editor collects the service's diagnostics itself. Read the text with state.text, the selections with state.selections, and edit with state.applyTextEdits(...); state.canUndo, undo() and redo() drive toolbar buttons. See the sample/ module for a runnable example.

The browser build is a WebAssembly module behind a Monaco-shaped API, published on npm as @aardarch/aardink-web with the built-in languages and themes:

pnpm add @aardarch/aardink-web

import { createEditor } from '@aardarch/aardink-web';

const editor = await createEditor(container, (text) => save(text), { value: source, language: 'xml' });

For a grammar or language service of your own written in Kotlin, build the module yourself instead: a small Gradle wasmJs module that depends on aardink-editor-web, with sample-web/ as the reference. docs/WEB_INTEGRATION.md covers both routes: the export template, npm packaging, Vite configuration, and a Monaco option mapping.

A language of your own can be registered from JavaScript as a Monarch grammar, with completions, hover and diagnostics answered by JavaScript functions, and a theme as Monaco's defineTheme data. docs/AARDFLEX_WEB_SWITCHOVER.md moves a real Monaco app over.

On the web: a keystroke settles in about 10 ms, and nearly always under 35 ms, whatever the size of the document (measured in docs/WEB_INTEGRATION.md). A disposed editor is not fully released until Compose Multiplatform 1.13, so reuse one editor rather than mounting a new one per view.

Themes are plain data classes. Wrap your editor in a CompositionLocalProvider(LocalEditorTheme provides …) to apply a theme, or pass one directly to CodeEditorLayout. The library ships a set of ready-made themes via EditorThemes (e.g. VsCodeDark, MidnightOcean). Custom themes are just EditorTheme(...) instances.

To add a new language, implement these interfaces from the editor module:

• IncrementalTokenizer — syntax highlighting, and commentSyntax for toggling comments
• FoldingProvider — code folding
• LanguageService (optional) — completions, diagnostics, hover, signature help, quick fixes, definitions, references and formatting

Bundle them as a LanguageDefinition and register with LanguageRegistry. The languages/ module is a working reference.

For highlighting alone, no tokenizer code is needed: DeclarativeTokenizer(DeclarativeGrammar.parse(json)) highlights from a Monarch grammar (Monaco's format) as JSON, a line at a time and incrementally. Its tokens are NamedTokenTypes named by the grammar, which an EditorTheme colours by the longest dotted prefix it has an entry for, as Monaco's themes do.

./gradlew :sample:installDebug                       # Android
./gradlew :sample-desktop:run                        # Desktop (JVM)
./gradlew :sample-web:wasmJsBrowserDevelopmentRun    # Browser

Each GitHub release also attaches the Android APK and a static build of the browser sample.

To render screenshots of the start screen and every sample page, in every bundled theme, into screenshots/ (no device or emulator needed):

./scripts/capture-screenshots.ps1

./gradlew :editor:jvmTest :languages:jvmTest :languages-lsp:jvmTest    # JVM unit tests
./gradlew :editor:wasmJsBrowserTest :editor-web:wasmJsBrowserTest    # Browser tests (needs Chrome)
./gradlew checkAbiAll                                                  # Public ABI check
./gradlew :editor:spotlessApply :languages:spotlessApply :languages-lsp:spotlessApply :editor-web:spotlessApply   # Auto-format
./gradlew publishToMavenLocal                                          # Publish all libraries to ~/.m2
./gradlew :sample-web:npmPackage                                       # Build the npm package

For the full build/test/release workflow — including the scripts/pre-push.ps1 end-to-end check — see AGENTS.md.

Contributions are welcome. Please read:

• CONTRIBUTING.md — how to propose changes
• CODE_OF_CONDUCT.md — community expectations
• SECURITY.md — reporting vulnerabilities

Aardink follows Semantic Versioning. Breaking public-API changes require a major version bump. Release notes live in CHANGELOG.md.

Aardink is licensed under the Apache License, Version 2.0.