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

KNew on the Kotlin Blog: Evaluating Kotlin in Real Projects After experimenting in tests, many Java teams move to the next stage – using Kotlin in production. JetBrains-certified Kotlin Trainer @Peter Urs explains how to approach this safely, avoid common migration mistakes, and see Kotlin’s strengths in action. 👉 Read the second post in the Kotlin adoption series: kotl.in/adoption-guide-2-sl

Concurrent programming can be chaotic – subtle bugs, unpredictable behavior, and “impossible” results. Until now, there was no Kotlin-specific tool to catch these issues across platforms. kodee lost That’s why the JetBrains Research team created LitmusKt, a novel concurrency testing tool designed for Kotlin’s multiplatform environment (JVM, Native, and JavaScript). kodee happy LitmusKt systematically uncovers concurrency bugs that traditional tests miss, and it’s already making an impact. After helping fix Kotlin compiler issues, LitmusKt has been integrated into the Kotlin CI pipeline, ensuring every new compiler version benefits from automated concurrency testing. Discover how LitmusKt brings order to the mayhem of concurrent programming: 🔗 Finding Order in the Mayhem: A Novel Concurrency Testing Tool that Improved the Kotlin Compiler

Hey Kotlin developers! We’ve heard the “how do I get started with KMP?” question a lot. So we’ve launched the KMP Level Up journey — a free, 4-week guided path to help. Here’s the plan, week by week: • Week 1: The Map 🗺️*.* A curated Course Matrix with our notes on the best free and paid learning resources. • Week 2: The Deep Dive 🤿*.* A brand new, free 3-hour Compose Multiplatform crash course from Philipp Lackner. • Week 3: The Real World 🌍*.* Top KMP talks from KotlinConf to see it in action. • Week 4: The Career 💼*.* A live, free webinar on making KMP your next career move. Plus, for those who want to go deeper, we’ve also arranged some exclusive discounts on premium content. 🔗 Everything is centralized on one page. This is your starting point to master the skills you need for 2026.

⏳ There are just 3 weeks left to submit your talk for KotlinConf’26 The KotlinConf’26 Call for Papers closes soon — you’ve got just three weeks left to submit your idea! We’d love to hear your Kotlin story. kodee loving ✍️ Submit your proposal here: https://sessionize.com/kotlinconf-2026/ Slack Conversation

KNew on the Kotlin blog – Building AI Agents in Kotlin – Part 1: A Minimal Coding Agent. In our new blog series, we kick things off by building a minimal coding agent in Kotlin with Koog, and evolve it step by step into a complete one. Read the first part here: ➡️ kotl.in/ai-agent-tutorial

kodee excited Calling all Kotlin enthusiasts! We need your feedback. Do you think that Kotlin’s documentation could be even more helpful? Participate in an unmoderated study to help us enhance your developer experience. 🕒 Task time: Max. 10 minutes 🎁 Everyone who takes part can choose either a USD 30 Amazon Gift Card or a three-month JetBrains All Products Pack subscription. 🔗 You'll need a Chromium-based desktop browser to take part in the study. Check if you qualify to participate in our research: https://surveys.jetbrains.com/s3/kotlin-docs-slack

👋 Android devs – have you tried this yet? Compose Multiplatform for web (Beta) lets you run your Compose UI directly in the browser – powered by Wasm. We’d love to know how you’d use it 👇 ⚡️ Instant web trials Share your Compose app instantly in the browser. Let users or teammates try new features through a simple web link – no installs, no approvals, just Kotlin and Compose Multiplatform. 🛠️ Internal applications Build internal dashboards, admin panels, or tools using the Kotlin and Compose skills you already have. Compose Multiplatform for web lets your team ship secure and responsive internal apps without touching JavaScript. 🤝 An improved developer workflow Share your Compose components or design system on the web and get instant feedback. Let designers and stakeholders review your UI in the browser without needing builds or test releases. 💡 Something else? Tell us what you’d build – vote with an emoji or share your idea in 🧵. Learn more about these use cases and Compose Multiplatform for web*.*

kmp logo Hey everyone! We are officially in the second half of “KMP Level Up” — our 4-week guided journey designed to help Android devs get hands-on with Kotlin Multiplatform before 2026. We just launched Week 3, which means the hub is updated with new resources. Here is a breakdown of what is available right now: 📺 New this week: The Ultimate KMP Watchlist We curated the definitive “Top 10" talks from KotlinConf to show how KMP works in the real world. We selected best talks that cover the full spectrum of adoption: • Massive production case studies (Duolingo & McDonald’s). • Live coding sessions to see the stack in action. • Deep dives into how the technology works under the hood. 🎓 Also available: Free Compose Multiplatform Course If you missed it last week, Philipp Lackner released a free 5-hour crash course where you build a complete Meme Creator app for Android & iOS. It’s a practical, project-based course that walks through the full UI sharing workflow. 🔮 Coming Up: Expert Panel with Jake Wharton & Zac Sweers Registration is now open for our Week 4 finale. It will be a live career-focused panel on “From Android Dev to KMP Pro,” featuring @jw, @Zac Sweers, @russhwolf and other great guests. You can find the watchlist, the crash course, and the webinar registration all on the campaign hub.

Don’t miss the KotlinConf Black Friday! kodee ghost

kodee greetings We’ve made a big update to the Kotlin documentation! 🎉 Based on community feedback, Kotlin Multiplatform docs have officially moved to kotlinlang.org. Now you can easily switch between Kotlin and KMP docs in one place. After all, KMP is built on Kotlin! We’ve also refreshed the table of contents and introduced a new navigation to make exploring the Kotlin ecosystem smoother and more intuitive. This is just the beginning – we’ll continue to experiment and improve the experience, allowing you to find what you need faster and enjoy using the docs more. kodee surprised Check out the new setup 👉 https://kotlinlang.org/

amper intensifies Amper 0.9.0 is out! amper intensifies This release brings a bunch of features that we’re excited about: • An initial preview of Amper’s extensibility capabilities – you can finally try Amper plugins and let us know what you think! • Dependency resolution graph caching • Incremental compilation for Java • Maven-like layout support (for easier transitions) • Auto-sync in the IDE when using IntelliJ IDEA 2025.3 Beta Plus plenty of new diagnostics and quality-of-life improvements! 👉 Check out our blog post and GitHub release notes for more info. 👈

K🤖 New blog post: Building AI Agents in Kotlin – Part 2 The next part of the AI agent series is out. This one shows how to extend Koog agents with tools, using a shell execution tool as an example. It covers: • The anatomy of a Koog tool (name, description, args, result, execute logic). • How to build an

ExecuteShellCommandTool

. • Handling confirmation, sandboxing concerns, and Brave mode. • How timeouts work and why they matter for LLMs. • How the agent’s system prompts change to encourage test-driven behavior. • Benchmark results after adding execution capability. If you’re experimenting with agents, this post provides a good overview of how tool design works in Koog. ➡️ Read it here: https://kotl.in/koog-tutorial-2