jarp-mcp

Java Archive Reader Protocol— Give AI agents X-ray vision into compiled Java code

Add this to your AI editor's MCP configuration:

{ "mcpServers": { "jarp-mcp": { "command": "npx", "args": ["-y", "jarp-mcp"] } } }

That's it.No installation. No configuration. CFR decompiler bundled.

What this enables:Your AI agent (Claude, Cursor, Windsurf, Cline, etc.) can now:

- Decompile any Java class from your dependencies
- Analyze class structure, methods, and fields
- Read actual source code instead of guessing

Restart your AI editor and try:"Show me the source code for JpaRepository"

AI agents like Claude, GPT-4, and Cursorcannot read compiled Java code. When working with Spring Boot, Maven, or any Java project:

"Show me how JpaRepository.saveAll() works"→ Agenthallucinatesthe method signature

"What parameters does this internal library function take?"→ Agentguesseswrong

"Why does this dependency throw this exception?"→ Agentcannot seethe source

Developers spend 5-10 minutes per classmanually decompiling with JD-GUI, copying source, and pasting into chat.

JARP-MCPgives AI agents instant access to decompiled Java source code from your Maven & Gradle dependencies.

┌─────────────┐ ┌──────────────────┐ ┌─────────────────┐ │ LLM Agent │ ───▶ │ JARP-MCP │ ───▶ │ Maven/Gradle │ │ (Claude/ │ │ (MCP Server) │ │ + .m2 Repo │ │ Cursor) │ │ │ │ │ └─────────────┘ └──────────────────┘ └─────────────────┘ │ ▼ ┌──────────────┐ │ CFR 0.152 │ │ Decompiler │ └──────────────┘

// In your AI assistant chat: "Scan my Spring Boot project and decompile JpaRepository"

- Scan all dependencies inpom.xml
- Find the JAR containingJpaRepository
- Decompile it using CFR
- Return the actual source code

Result:Accurate answers based on real code, not guesses.

JARP-MCP ├── Language: TypeScript 5.7 ├── Runtime: Node.js 16+ ├── Protocol: Model Context Protocol (MCP) ├── Decompiler: CFR 0.152 (bundled) ├── Build: tsc ├── Package: npm (zero-setup with npx) └── License: Apache-2.0

- Zero external dependencies— CFR decompiler bundled (2.2MB JAR)
- Smart path resolution— Works withnpx,npm install -g, local dev
- Maven & Gradle support— Parsespom.xmlandbuild.gradle
- Intelligent caching— First decompile ~2s, subsequent <100ms
- Auto-indexing— Builds class index on-demand if missing

No installation required. Everything is bundled.

git clone https://github.com/tersePrompts/jarp-mcp.git cd jarp-mcp npm install npm run build

Quick Setup— Works with any MCP-compatible AI editor:

{ "mcpServers": { "jarp-mcp": { "command": "npx", "args": ["-y", "jarp-mcp"] } } }

Create.claude/mcp-config.jsonin your Java project root:

{ "mcpServers": { "jarp-mcp": { "command": "npx", "args": ["-y", "jarp-mcp"] } } }

macOS:~/Library/Application Support/Claude/claude_desktop_config.json

Windows:%APPDATA%\Claude\claude_desktop_config.json

{ "mcpServers": { "jarp-mcp": { "command": "npx", "args": ["-y", "jarp-mcp"] } } }

{ "mcpServers": { "jarp-mcp": { "command": "npx", "args": ["-y", "jarp-mcp"] } } }

{ "mcpServers": { "jarp-mcp": { "command": "npx", "args": ["-y", "jarp-mcp"] } } }

- Open Postman → Settings → MCP Servers
- Add new server:

{ "name": "jarp-mcp", "command": "npx", "args": ["-y", "jarp-mcp"] }

{ "mcpServers": { "jarp-mcp": { "command": "npx", "args": ["-y", "jarp-mcp"] } } }

{ "mcpServers": { "jarp-mcp": { "command": "npx", "args": ["-y", "jarp-mcp"] } } }

Real-world:Spring Boot project with 156 dependencies, 12,458 classes

- Initial scan: 45 seconds
- Each class: ~1.5s first time, instant thereafter

- npm:https://www.npmjs.com/package/jarp-mcp
- GitHub:https://github.com/tersePrompts/jarp-mcp
- MCP Protocol:https://modelcontextprotocol.io

- handsomestWei— Originaljava-class-analyzer-mcp-server
- Lee Benfield— CFR Decompiler
- Anthropic— Claude & MCP ecosystem

Access real-time Maven Central intelligence for fast and accurate dependency information.