Maven Decoder

Name: Maven Decoder
Author: salitaba

by salitabaversion 1.3.2i★ –iRuns on your computer

Registry nameio.github.salitaba/maven-decoder-mcp

Install

Overview

Description from the maker (original English)

Lets AI agents read the real source of any Maven dependency, decompiled from ~/.m2 or Central.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Other
You need to fill in: MAVEN_REMOTE_PASSWORD

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
You fill in yourself: MAVEN_REPOSITORY, MAVEN_REMOTE_REPOS, MAVEN_REMOTE_USERNAME, MAVEN_REMOTE_PASSWORD, MAVEN_OFFLINE, MAVEN_AUTO_DOWNLOAD, MAVEN_DECODER_CACHE_DIR

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "maven-decoder": {
      "command": "npx",
      "args": [
        "-y",
        "maven-decoder-mcp"
      ],
      "env": {
        "MAVEN_REPOSITORY": "your-value",
        "MAVEN_REMOTE_REPOS": "your-value",
        "MAVEN_REMOTE_USERNAME": "your-value",
        "MAVEN_REMOTE_PASSWORD": "your-value",
        "MAVEN_OFFLINE": "your-value",
        "MAVEN_AUTO_DOWNLOAD": "your-value",
        "MAVEN_DECODER_CACHE_DIR": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add maven-decoder --env MAVEN_REPOSITORY=your-value --env MAVEN_REMOTE_REPOS=your-value --env MAVEN_REMOTE_USERNAME=your-value --env MAVEN_REMOTE_PASSWORD=your-value --env MAVEN_OFFLINE=your-value --env MAVEN_AUTO_DOWNLOAD=your-value --env MAVEN_DECODER_CACHE_DIR=your-value -- npx -y maven-decoder-mcp

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "maven-decoder": {
      "command": "npx",
      "args": [
        "-y",
        "maven-decoder-mcp"
      ],
      "env": {
        "MAVEN_REPOSITORY": "your-value",
        "MAVEN_REMOTE_REPOS": "your-value",
        "MAVEN_REMOTE_USERNAME": "your-value",
        "MAVEN_REMOTE_PASSWORD": "your-value",
        "MAVEN_OFFLINE": "your-value",
        "MAVEN_AUTO_DOWNLOAD": "your-value",
        "MAVEN_DECODER_CACHE_DIR": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "maven-decoder": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "maven-decoder-mcp"
      ],
      "env": {
        "MAVEN_REPOSITORY": "your-value",
        "MAVEN_REMOTE_REPOS": "your-value",
        "MAVEN_REMOTE_USERNAME": "your-value",
        "MAVEN_REMOTE_PASSWORD": "your-value",
        "MAVEN_OFFLINE": "your-value",
        "MAVEN_AUTO_DOWNLOAD": "your-value",
        "MAVEN_DECODER_CACHE_DIR": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

MAVEN_REPOSITORY env
Path to the local Maven repository. Defaults to ~/.m2/repository.
MAVEN_REMOTE_REPOS env
Comma or whitespace separated list of remote Maven repository base URLs.
MAVEN_REMOTE_USERNAME env
Username for authenticating against private remote Maven repositories.
MAVEN_REMOTE_PASSWORD secret env
Password or token for authenticating against private remote Maven repositories.
MAVEN_OFFLINE env
Set to true to disable all network access and use only the local repository.
MAVEN_AUTO_DOWNLOAD env
Whether to automatically download missing artifacts from remote repositories. Defaults to true.
MAVEN_DECODER_CACHE_DIR env
Override directory used for decompilation and metadata caches.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 6, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account salitaba, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Otheri

More stars than 0% of the other 32497 servers in this category
Published to the registry more recently than 36% of the other 32497 servers in this category
Basic checks equal to or better than 100% of the other 32497 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Maven Decoder safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: MAVEN_REMOTE_PASSWORD

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.3.2) reached the registry 2 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js, Python (uv) on your computer.

What can I use instead?

In the same category: Spec Driven Development, Remote Desktop Commander, Zoo MCP

Alternatives

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Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

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README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

Maven Decoder MCP Server

Your agent guesses at library APIs it has never read. This makes it read them.

Lets AI agents read the actual source of any Maven dependency — decompiles jars from ~/.m2 or Maven Central, and diffs versions for breaking changes.

Ask an agent *"I'm upgrading org.jsoup:jsoup from 1.17.2 to 1.23.2 — what breaks?"* and without a way to read the jars it will answer from memory. With this server, compare_versions reads both jars and reports what actually changed:

	1.17.2 → 1.23.2
Breaking changes	45
Members removed	31
Members added	150
Classes with API changes	47 of 115 compared

Members are compared as declared, so one that moved to a supertype is reported as removed even though it may still be callable. The tool states this in its own output.

It works on artifacts that have no sources jar too: extract_class_info falls back to javap and returns parsed fields, methods, and bytecode version — which is exactly the case for the internal artifacts in a corporate Nexus.

Try it in one command

npx skills add https://github.com/salitaba/maven-decoder-mcp --skill maven-code-search

That installs the maven-code-search agent skill, which tells your agent when to reach for these tools. For a raw MCP server setup instead, see Installation.

🚀 Features

Core Functionality

Jar File Analysis: Deep inspection of jar files including metadata, manifests, and structure
Dependency Resolution: Complete dependency tree analysis with transitive dependencies
Source Code Extraction: Extract source code from source jars or decompile bytecode
Class Information: Detailed class signatures, methods, fields, and annotations
Search Capabilities: Find classes, methods, and dependencies across all artifacts
Version Management: Compare versions, find dependents, and track version conflicts

Online Maven Support

Maven Central Search: Find artifacts and classes that are not installed locally
Remote Version Listing: See every published version, not just the ones you have
On-Demand Download: Fetch any artifact (jar, sources, POM) into a local cache
Transparent Fallback: Every analysis tool automatically downloads a missing artifact, so decompiling a dependency you never installed just works
Mirror Friendly: Point it at a corporate Nexus/Artifactory, with optional credentials
Offline Mode: A single env var restores fully local, network-free behavior

Advanced Features

Decompilation Support: Integrated support for multiple Java decompilers (CFR, Fernflower, Procyon)
Conflict Analysis: Detect and analyze dependency version conflicts
Repository Navigation: Browse and explore the local Maven repository structure
Metadata Parsing: Extract and parse Maven POM files and metadata
Service Discovery: Find and analyze Java services and SPI implementations
Response Management: Intelligent pagination and summarization for large responses
Method Extraction: Extract specific methods from large Java classes
Integrity Checking: Downloads are verified against the repository's SHA-1 checksums

📦 Installation

Prerequisites

Java 8+ (for decompilation features)
Maven local repository (~/.m2/repository)
One of: Python 3.8+, Node.js 14+, or Docker

🚀 Quick Install

One-Line Install (Recommended)

curl -fsSL https://raw.githubusercontent.com/salitaba/maven-decoder-mcp/main/install.sh | bash

📋 Installation Methods

Method 1: uvx (Recommended)

# Install uv (if not installed)

curl -Ls https://astral.sh/uv/install.sh | sh

Ensure your shell PATH is updated (restart shell or eval as printed by installer)

Run the server via uvx (isolated, fast, no venv needed)

uvx maven-decoder-mcp

Optional: pick a specific Python

uvx --python 3.12 maven-decoder-mcp

Method 2: Node.js/npm

# Install globally

npm install -g maven-decoder-mcp

Or install locally

npm install maven-decoder-mcp

Run the server

maven-decoder-mcp

or if installed locally: npx maven-decoder-mcp

Method 3: Docker

# Pull and run

docker run --rm -it \ -v ~/.m2:/home/mcpuser/.m2 \ -v $(pwd):/workspace \ ali79taba/maven-decoder-mcp:latest

Method 4: From Source (Development)

# Clone repository

git clone https://github.com/salitaba/maven-decoder-mcp.git cd maven-decoder-mcp

Option A: Using Virtual Environment

python3 -m venv .venv source .venv/bin/activate # On Windows: .venv\Scripts\activate pip install -r requirements.txt pip install "git+https://github.com/modelcontextprotocol/python-sdk.git" ./setup_decompilers.sh

Option B: System-wide Installation (not recommended)

./setup_decompilers.sh

Windows

For a source checkout, use Python 3.10 or newer and a JDK on PATH. From the repository root, create and activate a virtual environment in PowerShell:

python -m venv .venv

.\.venv\Scripts\Activate.ps1 python -m pip install -e ".[dev]"

Point to your existing local Maven repository (drive-letter paths are supported)

$env:MAVEN_REPOSITORY = 'F:\data\repository' maven-decoder-mcp

In Command Prompt (cmd.exe), activate with .venv\Scripts\activate.bat and set the repository with set "MAVEN_REPOSITORY=F:\data\repository" instead. These environment settings apply to programs launched from that terminal; set them in your MCP client's environment when it launches the server separately.

Remote downloads use a separate cache, resolved in this order (empty values are skipped):

MAVEN_DECODER_CACHE_DIR: the complete cache directory; no subdirectory is appended.
XDG_CACHE_HOME: append maven-decoder-mcp\repository.
LOCALAPPDATA: append maven-decoder-mcp\repository.
Otherwise, ~/.cache/maven-decoder-mcp/repository under your home directory.

On Windows, this usually means %LOCALAPPDATA%\maven-decoder-mcp\repository; XDG_CACHE_HOME still takes precedence if set. The cache uses Maven's directory layout but stays separate from the real local repository so downloads do not interfere with Maven builds. Setting MAVEN_REPOSITORY does not change the cache location.

🔧 Configuration

For Cursor IDE

Add to your ~/.cursor/mcp_servers.json:

"maven-decoder": { "command": "uvx", "args": ["maven-decoder-mcp"] } }

For Other MCP Clients

The server runs as a standard MCP server and can be integrated with any MCP-compatible client.

🧠 AI Agent Skill

This repository includes a maven-code-search agent skill that tells AI coding agents when and how to use this MCP for searching installed Maven package code.

npx skills add https://github.com/salitaba/maven-decoder-mcp --skill maven-code-search

The skill is located at skills/maven-code-search and is ready for skills.sh indexing after the repository is pushed.

🛠️ Available Tools

Local Analysis

Tool	Description
`list_artifacts`	List artifacts in Maven repository with filtering
`analyze_jar`	Analyze jar file structure and contents
`extract_class_info`	Get detailed information about Java classes
`get_dependencies`	Retrieve Maven dependencies from POM files
`search_classes`	Search for classes across all jars, optionally filtered by annotation
`extract_source_code`	Decompile and extract Java source code
`extract_jar_resource`	Extract text resources such as `.proto` files, services, and metadata
`compare_versions`	Compare two versions, including a public API diff and breaking changes
`find_usage_examples`	Find classes that reference a given class or method
`get_dependency_tree`	Get complete dependency tree
`find_dependents`	Find artifacts that depend on a specific artifact
`get_version_info`	Get installed versions of an artifact (set `include_remote` to add published ones)
`analyze_jar_structure`	Analyze overall jar structure and metadata
`extract_method_info`	Extract specific method information from Java classes

Online (Maven Central)

Tool	Description
`search_maven_central`	Search Maven Central for artifacts by name, coordinates, or contained class
`get_remote_versions`	List every version published remotely, flagging which are installed
`download_artifact`	Download an artifact (jar/sources/POM) into the local cache; accepts `latest`

Tool parameters

Tool	Parameter	Type	Default	Description
`list_artifacts`	`group_id`	string	—	Filter by group ID (e.g., 'org.springframework')
`list_artifacts`	`artifact_id`	string	—	Filter by artifact ID (e.g., 'spring-core')
`list_artifacts`	`version`	string	—	Filter by version (e.g., '5.3.21')
`list_artifacts`	`sort_by`	string	name	Order results by: 'name' (group/artifact/version ascending, default), 'size' (largest jars first), or 'modified' (most recently modified first). Unknown values fall back to 'name'.
`list_artifacts`	`limit`	integer	50	Maximum number of artifacts to return
`list_artifacts`	`page`	integer	1	Page number for pagination
`list_artifacts`	`items_per_page`	integer	20	Items per page
`analyze_jar`	`group_id`*	string	—	Maven group ID
`analyze_jar`	`artifact_id`*	string	—	Maven artifact ID
`analyze_jar`	`version`*	string	—	Maven version
`analyze_jar`	`include_bytecode`	boolean	False	Include bytecode analysis
`analyze_jar`	`include_manifest`	boolean	True	Include JAR manifest
`analyze_jar`	`summarize_large_content`	boolean	True	Summarize large content automatically
`extract_class_info`	`group_id`*	string	—	Maven group ID
`extract_class_info`	`artifact_id`*	string	—	Maven artifact ID
`extract_class_info`	`version`*	string	—	Maven version
`extract_class_info`	`class_pattern`	string	—	Pattern to match class names (regex supported)
`extract_class_info`	`include_methods`	boolean	True	Include method signatures
`extract_class_info`	`include_fields`	boolean	True	Include field information
`extract_class_info`	`include_bytecode`	boolean	False	Include verbose javap bytecode output for matched classes
`extract_class_info`	`page`	integer	1	Page number for pagination
`extract_class_info`	`items_per_page`	integer	20	Items per page
`extract_class_info`	`summarize_large_content`	boolean	True	Summarize large content automatically
`get_dependencies`	`group_id`*	string	—	Maven group ID
`get_dependencies`	`artifact_id`*	string	—	Maven artifact ID
`get_dependencies`	`version`*	string	—	Maven version
`get_dependencies`	`include_transitive`	boolean	False	Include transitive dependencies
`get_dependencies`	`page`	integer	1	Page number for pagination
`get_dependencies`	`items_per_page`	integer	20	Items per page
`search_classes`	`class_name`	string	—	Class name to search for (supports wildcards)
`search_classes`	`package_pattern`	string	—	Package pattern to filter by
`search_classes`	`annotation`	string	—	Search for classes with specific annotation
`search_classes`	`case_sensitive`	boolean	True	Match class_name and package_pattern case-sensitively. Set false for a case-insensitive search (e.g. 'arraylist' matches 'ArrayList').

Only the beginning is shown; read the rest in the repo

Maven Decoder

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Otheri

Common questions

Alternatives

Spec Driven Development

Remote Desktop Commander

Zoo MCP

README from the maker

Maven Decoder MCP Server

Try it in one command

🚀 Features

Core Functionality

Online Maven Support

Advanced Features

📦 Installation

Prerequisites

🚀 Quick Install

One-Line Install (Recommended)

📋 Installation Methods

Method 1: uvx (Recommended)

Ensure your shell PATH is updated (restart shell or eval as printed by installer)

Run the server via uvx (isolated, fast, no venv needed)

Optional: pick a specific Python

uvx --python 3.12 maven-decoder-mcp

Method 2: Node.js/npm

Or install locally

Run the server

or if installed locally: npx maven-decoder-mcp

Method 3: Docker

Method 4: From Source (Development)

Option A: Using Virtual Environment

Option B: System-wide Installation (not recommended)

Windows

Point to your existing local Maven repository (drive-letter paths are supported)

🔧 Configuration

For Cursor IDE

For Other MCP Clients

🧠 AI Agent Skill

🛠️ Available Tools

Local Analysis

Online (Maven Central)

Tool parameters