title: Kotlin description: "Configure Kotlin language support in Zed, including language servers, formatting, and debugging."

Kotlin

Kotlin language support in Zed is provided by the community-maintained Kotlin extension. Report issues to: https://github.com/zed-extensions/kotlin/issues

• Tree-sitter: fwcd/tree-sitter-kotlin
• Language Server: kotlin/kotlin-lsp
• Alternate Language Server: fwcd/kotlin-language-server

Kotlin LSP

Kotlin LSP is the official language server for Kotlin, built by JetBrains. It is used by default.

It is downloaded and updated automatically. If you want to use a manually installed version instead, set the path to the kotlin-lsp.sh script from the release assets in your settings.json:

{
  "lsp": {
    "kotlin-lsp": {
      "binary": {
        "path": "path/to/kotlin-lsp.sh",
        "arguments": ["--stdio"]
      }
    }
  }
}

Note that the kotlin-lsp.sh script expects to be run from within the unzipped release zip file, and should not be moved elsewhere.

Kotlin Language Server

The community-maintained Kotlin Language Server can be used instead of Kotlin LSP by explicitly enabling it in your settings.json:

{
  "languages": {
    "Kotlin": {
      "language_servers": ["kotlin-language-server", "!kotlin-lsp", "..."]
    }
  }
}

Configuration

Workspace configuration options can be passed to the language server via lsp settings in settings.json.

The full list of lsp settings can be found here under class Configuration and initialization_options under class InitializationOptions.

JVM Target

The following example changes the JVM target from default (which is 1.8) to 17:

{
  "lsp": {
    "kotlin-language-server": {
      "settings": {
        "compiler": {
          "jvm": {
            "target": "17"
          }
        }
      }
    }
  }
}

JAVA_HOME

To use a specific java installation, just specify the JAVA_HOME environment variable with:

{
  "lsp": {
    "kotlin-language-server": {
      "binary": {
        "env": {
          "JAVA_HOME": "/Users/whatever/Applications/Work/Android Studio.app/Contents/jbr/Contents/Home"
        }
      }
    }
  }
}