JetWhale

JetWhale is a next-generation, extensible debugging tool inspired by Flipper.

It is built with Kotlin and Jetpack Compose, making it especially familiar and approachable for Kotlin / Android developers. Thanks to its Kotlin-first design, JetWhale can be introduced with a minimal learning curve.

Note

This project is under active development. We welcome feedback as we work toward a stable release. Please note that the Plugin SDK APIs are not yet finalized and may change in the future.

📖 Documentation: https://kitakkun.github.io/JetWhale/

Features

• 🐳 Powerful Debugging Platform

  • Provides a modern and rich debugging experience powered by Kotlin and Jetpack Compose
  • Supports debugging multiple sessions simultaneously
  • Debugging tools are implemented as plugins, which can be dynamically loaded at runtime as JAR files

• ⚙️ Easy Integration and Customization

  • DSL-based APIs allow you to quickly set up and configure JetWhale in your application
  • Customize the debugging experience by creating your own plugins using familiar Kotlin and Jetpack Compose paradigms

• 🛜 Type-safe Communication with kotlinx.serialization

  • Leverages kotlinx.serialization to enable type-safe communication between the debugger and debuggees

• ✅ Multiplatform Support

  • Supports Android, Desktop(JVM), iOS (Simulator & physical devices over the local network), and Web (Js, WasmJs) debuggees

• 🤖 MCP Server Support (Experimental)

  • JetWhale exposes a built-in MCP (Model Context Protocol) HTTP+SSE server, allowing AI agents (e.g. Claude) to interact with debuggee apps directly
  • Built-in tools include screenshot, click, type, scroll, drag, and getAccessibilityTree
  • Plugins can expose their own custom MCP tools by implementing JetWhaleMcpCapablePlugin

• 🔥 Hot-Reloadable Plugin Development

  • Build your own plugins in your own repository against the published SDK — no fork needed
  • runJetWhale downloads a real JetWhale host and launches it with your plugin loaded; edit your plugin, re-stage, and the host hot-reloads it — no restart
  • See Developing plugins

Developing plugins

JetWhale's debugging tools are plugins, and you can build your own in your own repository with a fast, hot-reload dev loop:

• Apply the published com.kitakkun.jetwhale.host Gradle plugin and compile against the published SDK.
• Run a real host with ./gradlew :myPlugin:runJetWhale (it downloads the host for your OS — no manual install).
• Re-stage on save with ./gradlew :myPlugin:stageDevPlugin -t; the host reloads your plugin without a restart — keeping its state for simple (method-body) edits, and recreating it for structural changes (see the limitations).

See Developing plugins for the full guide.