A Claude Code plugin that integrates Metals, the Scala Language Server.

• Code completions
• Go to definition / references
• Hover documentation
• Diagnostics (errors/warnings)
• Code formatting (via Scalafmt)
• Supports .scala, .sc, and .sbt files

Java 11 or later is required. Install via one of:

• SDKMAN (recommended): sdk install java 17.0.8-zulu
• Homebrew: brew install openjdk@17
• Nix: nix-env -iA nixpkgs.jdk17
• asdf: asdf plugin add java && asdf install java openjdk-17
• jabba: jabba install openjdk@17

# Install Coursier if needed
brew install coursier/formulas/coursier  # macOS
# or: curl -fL https://github.com/coursier/coursier/releases/latest/download/cs-x86_64-pc-linux.gz | gzip -d > cs && chmod +x cs && ./cs setup

# Install Metals
cs install metals

# Verify
metals --version

nix-env -iA nixpkgs.metals

Add to your ~/.claude/settings.json:

{
  "enabledPlugins": {
    "/path/to/scala-lsp": true
  }
}

Or clone and add:

git clone https://github.com/Veske/scala-lsp.git ~/.claude/plugins/scala-lsp

Then add "~/.claude/plugins/scala-lsp": true to enabledPlugins.

The LSP will auto-connect when you open Scala files.

The metals-launcher script automatically discovers:

• Java: SDKMAN, jabba, asdf, Homebrew, Nix, macOS java_home, system PATH
• Metals: Coursier bin directory, Nix profile, system PATH

Ensure Java 11+ is available:

java -version

If using a version manager, ensure it's initialized in your shell profile.

If installed via Coursier, add to your shell profile:

export PATH="$PATH:$HOME/.local/share/coursier/bin"
# or on macOS:
export PATH="$PATH:$HOME/Library/Application Support/Coursier/bin"

Metals works best with a build tool. Ensure your project has one of:

• build.sbt (sbt)
• build.sc (Mill)
• pom.xml (Maven)

• Metals Documentation
• Metals GitHub
• Coursier

Apache-2.0