LABSCO SUMMARY

It closes one specific gap: a model knows Spring and Guava, and knows nothing at all about com.yourcompany.

Point it at the local Maven and Gradle caches and the class, its method signatures and — where a sources jar exists — the real source come back, so the agent stops guessing at your private APIs. The author also ships a CLI-and-skill version and recommends it over this one for terminal coding agents, on the grounds that loading tool schemas costs more context than the lookups themselves.

What it is

An MCP server that indexes your local Maven repository and Gradle cache, then answers class, artifact and source lookups against them. It watches those directories and keeps the index current in the background.

What you get

Class search across the local jars for when an import such as com.company.util.Helper resolves to nothing in the workspace — one class or a batch of them
The source for a class, with the containing artifact identified: real source files where a sources jar exists, decompilation where it does not
Artifact search by groupId and artifactId coordinate, by keyword, or by class name, including which versions are built locally
Implementations of an interface or subclasses of a base class, found inside those jars — useful for tracking down SPI implementations
Non-class files inside jars by pattern: properties files, XML configuration, proto definitions
A manual re-scan of the repository when something new has just been installed

Requirements

Nothing to authorize — it reads directories on your own machine. Runs over stdio with npx -y maven-indexer-mcp@latest and auto-detects ~/.m2/repository and ~/.gradle/caches/modules-2/files-2.1. When they sit elsewhere, set MAVEN_REPO or GRADLE_REPO_PATH. INCLUDED_PACKAGES narrows what gets indexed to package patterns such as com.mycompany.* (default is everything), MAVEN_INDEXER_CFR_PATH points at your own CFR decompiler jar instead of the bundled one, and VERSION_RESOLUTION_STRATEGY picks between semver, latest-published and latest-used when several versions match.

Setup effort

One command — npx -y maven-indexer-mcp@latest

See installation options

USE CASES

01

Resolving an import the workspace cannot explain

Find the class in the local jars, then read its source or its decompiled form.

search_classesget_class_details

02

Finding who implements an internal interface

Search the caches for implementations or subclasses, then open the one you need.

search_implementationsget_class_details

03

Checking which version of an internal library is on this machine

Search by coordinate or keyword and see the versions built locally.

search_artifacts

04

Digging a config file out of a jar

Match non-class files by pattern — properties, XML or proto — without unzipping anything.

search_resources

05

Picking things up after a fresh local build

Trigger a re-scan so the newly installed artifacts are searchable.

refresh_index

6 tools

Counted once with only startup setup. Other versions, modes or optional credentials may expose a different list.

`get_class_details`

Retrieve the source code for a class from the local Maven/Gradle cache (containing internal company libraries). This tool identifies the containing artifact and returns the source code. It prefers actual source files but will fall back to decompilation if necessary. Use this primarily for internal company libraries that are not present in the current workspace. IMPORTANT: Even if the code compiles and imports work, the source code might not be in the current workspace (it comes from a compiled internal library). Use this tool to see the actual implementation of those internal libraries. Supports batch queries.

BEFORE YOU INSTALL

What to know first

Tools you get

6 tools when we connected. search_resources is registered but not documented anywhere.

Requires

your local Maven repository (~/.m2/repository) or Gradle cache (~/.gradle/caches/modules-2/files-2.1), found automatically — set MAVEN_REPO or GRADLE_REPO_PATH if yours is elsewhere

Where it runs

All 7 documented clients run the server on your machine.

CONTEXT COST

Light Standing cost

Rated by the size of the 6 tool definitions that ride along on every turn, not by how many there are

INSTALLATION

Connect your client

Server setup

TERMINAL

npx -y maven-indexer-mcp@latest

MCP Clients

Cline, Cursor, JetBrains IDEs, Kiro, Qoder, Trae, Windsurf

JSON

{
  "mcpServers": {
    "maven-indexer": {
      "command": "npx",
      "args": [
        "-y",
        "maven-indexer-mcp@latest"
      ]
    }
  }
}

Maven Indexer MCP Server

It closes one specific gap: a model knows Spring and Guava, and knows nothing at all about com.yourcompany.

What it is

What you get

Requirements

Setup effort

Resolving an import the workspace cannot explain

Finding who implements an internal interface

Checking which version of an internal library is on this machine

Digging a config file out of a jar

Picking things up after a fresh local build

6 tools

`get_class_details`

`refresh_index`

`search_artifacts`

`search_classes`

`search_implementations`

`search_resources`

What to know first

Tools you get

Requires

Where it runs

Light Standing cost

Connect your client

Server setup

MCP Clients

Cline, Cursor, JetBrains IDEs, Kiro, Qoder, Trae, Windsurf

Maven Indexer MCP Server

It closes one specific gap: a model knows Spring and Guava, and knows nothing at all about com.yourcompany.

What it is

What you get

Requirements

Setup effort

Resolving an import the workspace cannot explain

Finding who implements an internal interface

Checking which version of an internal library is on this machine

Digging a config file out of a jar

Picking things up after a fresh local build

6 tools

get_class_details

refresh_index

search_artifacts

search_classes

search_implementations

search_resources

What to know first

Tools you get

Requires

Where it runs

Light Standing cost

Connect your client

Server setup

MCP Clients

Cline, Cursor, JetBrains IDEs, Kiro, Qoder, Trae, Windsurf

Same category

JVM Source Lens

Jarp MCP

Fossick

TokRepo MCP Server

`get_class_details`

`refresh_index`

`search_artifacts`

`search_classes`

`search_implementations`

`search_resources`