Best of JetBrains — March 2026

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   JetBrains·7w

   Core JavaScript and TypeScript Features Will Be Free in IntelliJ IDEA

   JetBrains is making core JavaScript, TypeScript, HTML, and CSS features free in IntelliJ IDEA starting with v2026.1. Previously restricted to Ultimate subscribers, the free tier will now include syntax highlighting, code completion, import management, basic React support, code navigation, refactorings, quality inspections, and integrated tooling for Prettier, ESLint, Vite, and NPM scripts. Advanced features like dedicated debuggers, test runners, and full framework support (Angular, Vue) remain part of the Ultimate subscription, which offers a 30-day free trial.

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   JetBrains·7w

   How We Taught AI Agents to See the Bigger Picture

   AI agents writing code for large legacy codebases tend to repeat outdated patterns because they mistake frequency for correctness. The JetBrains TeamCity team tackled this by building CommitAtlas, an internal tool that mines Git history to extract accepted patterns, naming conventions, and migration examples. Before writing code, agents query CommitAtlas for task-specific guidance derived from real, reviewed commits rather than raw codebase frequency. This approach reduced pull request rejections and helped agents produce code that fits the project's evolving standards rather than its historical defaults. The core insight: repository history is implicit documentation, and giving agents access to it bridges the gap between technically correct and genuinely acceptable code.

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   JetBrains·7w

   Java 26 in IntelliJ IDEA

   Java 26 was released on March 17, 2026, delivering ten JEPs with five finalized. There are no new stable language features, but notable additions include HTTP/3 support in the HTTP Client API, AOT cache improvements for any garbage collector (Project Leyden), G1 GC throughput improvements, warnings for deep reflection on final fields, and removal of the Applet API. Preview features include primitive types in patterns (fourth preview), lazy constants (formerly stable values), structured concurrency, and PEM encoding/decoding. The Vector API continues as an incubator feature. IntelliJ IDEA 2026.1 supports all Java 26 features from day one, including new inspections, debugger improvements for virtual threads in structured concurrency, and tooling for lazy constants. A JetBrains contributor also added min/max default methods to java.util.Comparator in the JDK.

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   JetBrains·7w

   IntelliJ IDEA 2025.3.4 is Out!

   IntelliJ IDEA 2025.3.4 has been released, bringing full support for Java 26 as the headline feature. The update also includes several bug fixes: a fix for HTTP requests accidentally triggering other requests in the same file, improved local changes refresh in large Perforce projects, and a correction for the Dependencies tab when using Analyze Cyclic Dependencies. The update is available via the IDE itself, Toolbox App, snaps, or direct download.

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   JetBrains·7w

   Koog Comes to Java: The Enterprise AI Agent Framework From JetBrains

   JetBrains has launched Koog for Java, bringing its AI agent framework to the JVM with a fully idiomatic Java API. The framework lets Java teams build AI agents directly in existing backends without Python microservices. Key features include multiple workflow strategies (functional, graph-based, and GOAP planning), Spring Boot integration, support for major LLM providers (OpenAI, Anthropic, Google, DeepSeek, Ollama), fault-tolerant persistence (Postgres, S3, disk) that resumes from the exact failure point, OpenTelemetry observability with Langfuse and W&B Weave support, history compression to manage token costs, and fine-grained Java thread pool control via ExecutorService configuration.

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