IntelliJ IDEA Goes LSP: Java and Kotlin Intelligence Comes to VS Code, Cursor, and Agentic Flows

Marco Behler

It’s no secret that agentic development is changing how developers build software. As agents take on more and more of the implementation work, developers spend less and less time manually editing code. 

For this manual work, they might only need a basic, narrow set of features that IDEs provide, like navigating to declarations, finding references, some simple code completion, or renaming.

These features are generally covered by the Language Server Protocol (LSP), which allows programming language support to be implemented once and then reused by any LSP-capable IDE or editor. 

Even agents can make use of LSP servers today, leading to faster and more deterministic results and, eventually, reduced token consumption. 

In response to these changes, we’ve been working hard at JetBrains to offer IntelliJ IDEA’s smart language features for Java and Kotlin in an LSP format.

Today, we’re happy to announce that IntelliJ IDEA’s Java and Kotlin intelligence is available in a preview extension for third-party editors, starting with VS Code and its forks (such as Cursor).

We have also been running internal trials and experiments with a select few external customers, and the results have shown that the same LSP functionality can significantly improve terminal-based agentic workflows, like with Claude Code or Codex. We will share the very promising results of these experiments soon.

Introducing the VS Code extension

The Java & Kotlin by IntelliJ IDEA extension is now available, powered by IntelliJ IDEA’s Java and Kotlin language technology. It brings a focused set of capabilities to VS Code-based editors, including:

• Java, Kotlin, and mixed-language project support.
• Smart code completion, navigation, and code analysis.
• Refactorings and editor assistance.
• Support for Maven, Gradle, and Bazel.
• Fast and reliable performance, even for large projects and monorepos.

You can find the full list of features in our documentation.

Getting started

You can install the Java & Kotlin by IntelliJ IDEA extension from the Visual Studio Marketplace and the Open VSX registry.

Install from Visual Studio Marketplace

Install from Open VSX registry

After installation, open your Java or Kotlin projects in VS Code or Cursor. 

The extension will start analyzing your projects, import the ones that have Maven, Gradle, or Bazel build files, and then enable Java and Kotlin language features in the editor for you.

Compatibility notice

Java & Kotlin by IntelliJ IDEA includes code analysis features and quick-fixes that overlap with Red Hat’s and Oracle’s extensions for Java. To avoid confusion, we recommend disabling those extensions while testing.

Licensing

During the preview phase, the extension is free to use. Each build is limited to 30 days.

After the preview  period, using the extension will require an IntelliJ IDEA Ultimate license. 

The same license will let you use IntelliJ IDEA’s Java and Kotlin capabilities whether you are working in the IntelliJ IDEA desktop IDE, in VS Code-based editors, or in other supported environments. You can review the pricing options here.

What’s next

The VS Code extension is just one milestone in a longer development journey to bring the intelligence of IntelliJ IDEA to our users wherever they are. 

We strongly believe the best way to do Java and Kotlin development is inside IntelliJ IDEA. At the same time, we recognize that teams may have practical reasons to work in other environments, with other editors and tools. Wherever you choose to work, we want you to benefit from IntelliJ IDEA’s Java and Kotlin intelligence.

To this end, we’re already working on supporting fully agentic, terminal-based workflows. In the near future, we’ll share our initial results (think: reduced token consumption), and we’ll give you a chance to try out our agent plugins when they’re ready.

Feedback and support

We are eager to hear what you think. 

Please share feedback with us about what works well, what doesn’t, and which capabilities you would like to see next.

You can leave a comment here or submit a request to us.

Your feedback during this preview phase will directly shape the extension as we move toward a stable 1.0 release.

Thank you!

Get the extension: Visual Studio Marketplace

Get the extension: Open VSX registry