K🧪 Breaking to Build: Fuzzing the Kotlin Compiler How do you find bugs in a compiler? Sometimes, you just have to break it. We use fuzzing to uncover bugs in the Kotlin compiler by throwing random inputs at it. In our new post, you’ll learn all about: 🐛 Issues we found in K2 🧠 A new approach we developed with TU Delft Curious what happens when you push a compiler to its limits? 👉 Read more: kotl.in/compiler-fuzzing

K*The Kotlin Library Grants Program is open again for 2025!* Whether your library already supports Kotlin Multiplatform, is set to go Multiplatform in the future, or unlocks capabilities in areas like AI or large language models, this opportunity is for you. Grants include financial support, promotion through Kotlin channels, and other perks. 📆 Submit your application by July 31: https://kotlinfoundation.org/grants/

🎉 KotlinConf 2026 is happening in Munich on May 20–22! Early Bird tickets are still available (but they’re going fast). If you haven’t grabbed yours at the best price yet, now’s the perfect time. We can’t wait to welcome you in Munich, whether it’s your first KotlinConf or you’re coming back for more. Oh, and don’t miss Kodee’s electrifying new look for 2026! kodee electrified 👉 https://kotlinconf.com/

Hey everyone! kodee welcoming Some huge news we’re incredibly excited to share: We’re officially Gold Sponsors for RevenueCat Shipaton 2025 - the biggest mobile hackathon of the year! But here’s the best part for our community: we’ve launched our own prize category, and it’s all about showing the world what KMP can do. Introducing: > 🏆 The Kotlin Multiplatform Reach Award > For the team that ships the best, uncompromising app on both iOS and Android with Kotlin Multiplatform and/or Compose Multiplatform. Bonus points will be awarded for teams that also share their development journey with the community. For the team that ships the best, uncompromising app on both iOS and Android with Kotlin and Compose Multiplatform. Bonus points will be awarded for teams that also share their development journey with the community. This is your chance to build an amazing app with Kotlin and Compose Multiplatform and compete for a share of the $55,000 prize pool! We wrote a blog post with ALL the details, links to resources to get you started, and info on how to apply for the exclusive “Ship with Junie” program. Check it out here. Let’s show them what the Kotlin community can build! 🔥

📣

Gradle 9.0.0

is out! 🔧 Configuration Cache is now the recommended execution mode ☕ Gradle requires Java 17+ to run, but you can still build with older Java versions 💼 Updated to Kotlin 2.2 and Groovy 4.0. It means new language features in the DSLs ⚡ Improved Kotlin DSL build script compilation avoidance What’s new in Gradle 9? https://gradle.org/whats-new/gradle-9/ Release video: Full changelog: https://docs.gradle.org/9.0.0/release-notes.html Please report any issue on GitHub - https://github.com/gradle/gradle/issues ! Slack Conversation

📣 Join our Koog livestream series on August 12 and 18. Whether you’re a Kotlin developer or simply curious about building intelligent systems, this series will guide you from the basics to advanced use cases. Learn directly from the creators of Koog and share your feedback. 🔗 Register here.

🤖 GPT-5 is out, and of course it writes great Kotlin code! We're putting it to the test in JetBrains Junie and AI Assistant. 📅 Join today at 18:15 CET as Sebastian Aigner and Simon Vergauwen build with the latest OpenAI model!

🚀 Big news from the Kotlin Foundation! We’re excited to welcome Sergei Rybalkin, Senior Staff Software Engineer at Meta and longtime Kotlin champion, to the board! 🎉 With his technical leadership and community insight, Sergei will help shape the future of Kotlin across platforms, industries, and teams. Let’s give him a warm welcome! 👏 kodee welcoming 🔗 Read the news 🔗

📣 Kotlin devs, we want to hear from you! We're running a survey to understand the challenges and experiences you face with Kotlin – whether it's the language, the tools, or the IDEs. Your feedback is essential in helping us improve the usability of Kotlin. It only takes 10 minutes! 🙌 Share your thoughts with us here: Kotlin Developer Survey kodee loving

K The Kotlin 2.2.10 release is out! This version includes performance improvements and bug fixes for Kotlin 2.2.0. Check out the changelog for more details: https://github.com/JetBrains/kotlin/releases/tag/v2.2.10

kodee happy The last six months have been huge for Kotlin! kodee happy From major feature releases to stability milestones, here’s what we’ve achieved together: ✅ Kotlin Language Server Protocol is now in Preview ✅ Compose Multiplatform for iOS is now Stable ✅ We’ve released a new Kotlin Multiplatform plugin for IntelliJ IDEA and Android Studio ✅ The Kotlin Rich Errors feature is in development ✅ The Kotlin 'Unused return value checker' will be available in Kotlin 2.3 ✅ Kotlin Notebook is now bundled in IntelliJ IDEA ✅ Junie, the AI coding agent by JetBrains, is now available for Android Studio 🚀 And the next six months are looking even more exciting! Check out our updated Kotlin roadmap to see what’s coming next. 👉 KOTLIN ROADMAP UPDATE 👈

Kkotlin notebook New on the Kotlin blog – Exploring Data Science With Kotlin: A Powerlifting Case Study! In this quest post, @Adele Carpenter uses a real-world powerlifting dataset to explore: 📊 Analyzing data with Kotlin Notebooks + DataFrame + Kandy 🗄️ Pulling and transforming data from PostgreSQL 📈 Plotting results with just a few lines of code 👉 Read it here: https://kotl.in/powerlifting-case-study Many thanks to Adele for sharing her experience with the Kotlin community!

Koog 0.4.0 is out! It brings practical upgrades for building production-ready agents in Kotlin: ✔️ Full observability with OpenTelemetry support for Langfuse and W&B Weave ✔️ Drop-in Ktor integration ✔️ Native structured output with fallbacks and fixing strategies ✔️ iOS support via Kotlin Multiplatform ✔️ GPT-5 and custom tuning params ✔️ Production-grade retry logic Learn more: https://kotl.in/koog-0-4-0-release

K🤖 Want to build AI into your Kotlin backend? Spring AI is a toolkit that connects your Kotlin app to large language models (LLMs), vector databases, and backend tools – with minimal setup and full flexibility. With Spring AI and Kotlin, you can: ✅ Generate text using LLMs (OpenAI, HuggingFace, and local models) ✅ Stream responses to the UI ✅ Build RAG pipelines with semantic search ✅ Call backend tools from natural language ✅ Generate images or audio from text ✅ Produce structured, type-safe outputs And the best part? We’ve published runnable Kotlin notebooks showing exactly how to do each of these. 📚 Explore the tutorials

🚀 What’s Next for Kotlin Multiplatform and Compose Multiplatform 🚀 We’ve recently published a new blog post outlining our priorities and the direction for Kotlin Multiplatform and Compose Multiplatform. Explore our plans for the next six to twelve months and see where the journey is headed. 👉 Read the full blog post 👈

🚀 A new series of educational articles about Koog has launched! @Vadim Briliantov, the tech lead for Koog at JetBrains, has started publishing a series that will cover fault tolerance, cost optimization of AI agents, observability and debugging AI applications with Langfuse and W&B Weave, building AI agents for mobile (iOS & Android), and more. 💡 Share in the thread what else you’d like to learn about building production-ready AI (or what you think might be missing in the Koog framework), Vadim will be following the discussion and may cover your suggestions in upcoming articles. 👉 The first three articles are already out, check them out on Medium: https://medium.com/@vadim.briliantov

kodee greetings We’re looking for your feedback! kodee greetings We're testing a landing page and need honest reactions from developers and the tech-savvy community. 🎁 Everyone who completes the task with meaningful input gets a reward (a USD 50 Amazon Gift Card OR a 6-month JetBrains All Products Pack subscription!) 🎥 You’ll need to record your screen and voice (desktop only) 👉 Start with a quick eligibility survey 👈 Note: For this study, we’re looking for participants without Kotlin Multiplatform experience.

K The Kotlin 2.2.20 release is out and brings important changes for web development! Kotlin/Wasm is now Beta, with improvements to exception handling in JavaScript interop, npm dependency management, built-in browser debugging support, and a new shared source set for js and wasmJs targets. Additionally, here are some main highlights: ✅ Language: Improved overload resolution when passing lambdas to overloads with suspend function types. ✅ Kotlin Multiplatform: Swift export available by default, stable cross-platform compilation for Kotlin libraries, and a new approach for declaring common dependencies. ✅ Kotlin/Native: Support for stack canaries in binaries and smaller binary size for release binaries. ✅ Kotlin/JS: Long values compiled into JavaScript BigInt. Learn more: http://kotl.in/2.2.20

📣 KotlinConf'26 is calling for speakers! kotlinconf2026 Got a Kotlin story to tell? Submit your talk idea and be part of shaping this year’s event!

🎥 New livestream! Your Voice Belongs Here: Creating Compelling KotlinConf Proposals This supportive session is designed for people from underrepresented groups in tech who already have some speaking experience and want to take the next step. Join Pamela Hill and Cheuk Ting Ho as they share practical tips, encouragement, and a no-gatekeeping approach to crafting outstanding proposals. 💡 Let’s get your KotlinConf talk ready – because your voice belongs here! 🗓️ Save the date: https://info.jetbrains.com/kotlin-livestream-october14-2025.html

📢 Kotlin DataFrame 1.0.0-Beta3 is out — bringing us one step closer to 1.0! This update brings Parquet and DuckDB support, better compile-time schema tracking via the Compiler Plugin, and a big refresh of docs and examples — including examples of using DataFrame together with Android, Apache Spark, Hibernate, Exposed, and more. Here are the highlights: ✅ NEW: Read data directly from Parquet files ✅ NEW: Read data from DuckDB databases ✅ Docs: Major updates across the board — setup guides, plugin usage, data sources, FAQs, and more ✅ Examples of usage: Android, Apache Spark + Parquet, Hibernate, Exposed & more ✅ Improvements to format to HTML ✅ Compiler plugin improvements for better schema tracking at compile time Release notes: https://github.com/Kotlin/dataframe/releases/tag/v1.0.0-Beta3 📚 Learn more: https://kotlin.github.io/dataframe/ 🌟 Examples: https://github.com/Kotlin/dataframe/tree/master/examples

🎉 Compose Multiplatform for web goes Beta in the 1.9.0 release! kodee happy Now is the perfect time to bring your Compose code and skills to the browser with minimal effort. Extend your apps beyond mobile and desktop to the web. kodee walking Learn more in our latest blog post: https://kotl.in/cmp190-slk

K New on the Kotlin blog: The Kotlin AI Stack: Build AI Agents With Koog, Code Smarter With Junie, and More Learn about: • Koog for agent workflows • Junie in IntelliJ IDEA for end-to-end tasks • SDKs in Kotlin for model calls • Spring AI for higher-level wiring • The MCP for sharing tools across agents Check it out: https://kotl.in/vkbg7z

kmp logo The Kotlin Multiplatform plugin for IntelliJ IDEA is now on Linux and Windows! 🚀 Build for Android, desktop, and web – with all the latest web improvements included. kodee walking Install now: https://kotl.in/kmp-plugin P.S. Android Studio is coming soon, so stay tuned!

ktor new The Ktor roadmap for 2025–2026 is here! Here's what we'll be working on: • API docs (OpenAPI is already in preview) • WebRTC Client with a Multiplatform API • Integration with Koog • and more! 🔗* Explore what’s next for Ktor*

📢 kodee naughty Koog 0.5.0 is out! This release makes agents in Kotlin more connected, more reliable, and easier to customize. Here’s what’s new: ✔️ A2A Protocol support with a full multiplatform SDK. ✔️ Non-graph agent strategies – build flows with plain Kotlin. ✔️ Checkpoint rollbacks with side-effect cleanup. ✔️ subgraphWithTask now auto-generates finish tools by data types with no manual work required. ✔️ Simplified Tool API across JVM and multiplatform. ✔️ LLM-as-a-judge component. ✔️ Streaming API supports tool calls. Full release notes: https://github.com/JetBrains/koog/releases/tag/0.5.0

kodee happy This year’s Kotlin Multiplatform Contest for students and recent graduates is open. Build a project using KMP, and it could take you to KotlinConf 2026 in Munich, Germany!

🎤 Ready to share your Kotlin story on the big stage? The KotlinConf’26 Call for Papers is in full swing! Check out our blog post with insider tips to help your submission shine. ✨ Learn how to craft a standout proposal with guidance from veteran presenters, JetBrains speakers, and KotlinConf committee members. 👀 Read more: https://kotl.in/conf26-proposal-tips

kodee greetings We’re running our yearly Kotlin Multiplatform survey to understand how the ecosystem is growing, how our recent releases are performing, and where to focus our efforts next. Your experiences matter! kodee loving Take a few minutes to share your feedback 👉 Link to the survey 👈

K New on the Kotlin blog: Getting Started with Kotlin for Java Developers JetBrains-certified Kotlin Trainer @Peter Urs explains how teams begin their Kotlin journey – what sparks the first experiments, who drives the change, and why tests are often the safest place to start. 👉 Read the first part in the series about adopting Kotlin: https://kotl.in/kotlin-adoption-part-1