JLens MCP Server

A Model Context Protocol (MCP) server for inspecting Java classes and Maven dependencies.

Key Features

• Java Class Inspection: Inspect any Java class in your project or dependencies.
• JDK Visibility: Support for inspecting JDK classes with @since information (requires javaHome).
• Maven Integration: Deep resolution of Maven dependency graphs, including property placeholders.
• Granular Detail Levels: Support for skeleton, basic, and full detail levels in class inspection.
• Interface Support: Fully supports listing fields and methods for Java interfaces.

JDK Inspection with @since

To get accurate versioning information for JDK classes, provide the javaHome parameter to the inspect_java_class tool. JLens will automatically locate src.zip and extract Javadoc info.

Quick Execution

You can run JLens instantly using npx or uvx (requires Java 25+ installed):

# Using npx
npx -y @bhxch/jlens-mcp-server

# Using uvx
uvx jlens-mcp-server

Environment Variables

You can configure the server using environment variables:

• JLENS_JAVA_HOME: Path to Java installation (overrides JAVA_HOME)
• JLENS_ARGS: Additional JVM arguments or server options

# Example
JLENS_JAVA_HOME="/path/to/jdk-25" JLENS_ARGS="-Dfile.encoding=UTF-8" npx @bhxch/jlens-mcp-server

Agent Skills

Install specialized AI agent skills to help your agent use JLens more effectively (requires npx skills support):

# Install Chinese Version
npx skills install https://github.com/bhxch/jlens/tree/main/skills/jlens-mcp

# Install English Version
npx skills install https://github.com/bhxch/jlens/tree/main/skills/jlens-mcp-en

Documentation

• User Guide: docs/user-guide/
  • English README
  • 中文 README
  • Testing Guide
• Developer Docs: docs/developer-docs/
  • Project Summary
  • Integration Guide
  • Contributing Guide (中文版)
• Design Plans: docs/plans/

Quick Links

• Test Reports: docs/developer-docs/reports/ - Test results and reports
• Scripts: scripts/ - Test and automation scripts
• Configuration: config/ - MCP Inspector and other configs
• Logs: logs/ - Temporary logs and outputs

Build & Run

Build

# Recommended for JDK 25+ due to test engine compatibility
mvn clean package -DskipTests

This will create an executable JAR file: target/jlens-mcp-server-1.1.2.jar

License

MIT