# Kotlin & Java Library Sources MCP server

> Read the real sources, public API and KDoc of any Maven-published Kotlin or Java library from its sources jar.

- Listing: https://mcp.tc/i/kotlin-java-library-sources
- Connect: this is a local (stdio) server; install it on your machine (see Install). The listing link is a page, not an MCP endpoint.
- Type: local (stdio)
- Auth: no API key needed
- Category: [Developer Tools](https://mcp.tc/c/developer-tools)
- Vendor: aoreshkov
- Repository: <https://github.com/aoreshkov/kotlin-lib-mcp>
- Package: oci `ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0`

## About

Downloads the sources jar of a Maven or Gradle-published Kotlin or Java library, parses it with the Kotlin Analysis API, and returns type-resolved public API signatures, KDoc, dependencies, raw source and source search. Kotlin Multiplatform libraries are resolved per target. Results are cached on disk by group, artifact and version.

Runs locally over stdio from a Docker image (ghcr.io/aoreshkov/kotlin-lib-mcp) or from a release zip that needs Java 21 or newer. An HTTP transport is available and binds to loopback by default. No API key or sign-in is needed; Maven Central is the default repository.

## What it can do

- Fetch and cache a library's sources by group, artifact and version
- List packages and declarations of a library
- Get type-resolved API signatures
- Read KDoc for a declaration
- Read raw source and search it
- Diff two versions of a library
- List dependencies, versions and the latest version

## Example prompts

- "Fetch io.ktor:ktor-client-core:3.5.1 and list its public packages."
- "Show the API signature and KDoc for HttpClient in Ktor 3.5.1."
- "What changed in the public API between these two versions of this library?"
- "What is the latest version of kotlinx-coroutines-core?"

## Install

### Claude Code

1. Run this in a terminal, in your project folder:

```bash
claude mcp add --transport stdio kotlin-java-library-sources -- docker run -i --rm ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0
```

2. Start Claude Code and type `/mcp`. **kotlin-java-library-sources** should show as connected.

Add `--scope user` to make it available in every project.

### Claude Desktop

1. Open **Settings → Developer → Edit Config**. It opens `claude_desktop_config.json`. Add:

`claude_desktop_config.json`:

```json
{
  "mcpServers": {
    "kotlin-java-library-sources": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0"
      ]
    }
  }
}
```

2. Save the file and restart Claude Desktop.

Needs Docker on your computer. The file lives in `~/Library/Application Support/Claude/` on macOS and `%APPDATA%\Claude\` on Windows.

### Cursor

[Add to Cursor](<https://cursor.com/install-mcp?name=kotlin-java-library-sources&config=eyJjb21tYW5kIjoiZG9ja2VyIiwiYXJncyI6WyJydW4iLCItaSIsIi0tcm0iLCJnaGNyLmlvL2FvcmVzaGtvdi9rb3RsaW4tbGliLW1jcDowLjcuMCJdfQ%3D%3D>) (opens Cursor)

Or add it by hand to `~/.cursor/mcp.json` (all projects) or `.cursor/mcp.json` (this project):

`mcp.json`:

```json
{
  "mcpServers": {
    "kotlin-java-library-sources": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0"
      ]
    }
  }
}
```

Needs Docker on your computer.

### VS Code

[Install in VS Code](<https://vscode.dev/redirect/mcp/install?name=kotlin-java-library-sources&config=%7B%22type%22%3A%22stdio%22%2C%22command%22%3A%22docker%22%2C%22args%22%3A%5B%22run%22%2C%22-i%22%2C%22--rm%22%2C%22ghcr.io%2Faoreshkov%2Fkotlin-lib-mcp%3A0.7.0%22%5D%7D>) (opens VS Code)

Or from a terminal:

```bash
code --add-mcp '{"name":"kotlin-java-library-sources","type":"stdio","command":"docker","args":["run","-i","--rm","ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0"]}'
```

Or commit it to the repo in `.vscode/mcp.json`:

`.vscode/mcp.json`:

```json
{
  "servers": {
    "kotlin-java-library-sources": {
      "type": "stdio",
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0"
      ]
    }
  }
}
```

Needs Docker on your computer.

### Devin Desktop

1. Add it to `~/.config/devin/mcp_config.json` (macOS and Linux) or `%APPDATA%\devin\mcp_config.json` (Windows):

`mcp_config.json`:

```json
{
  "mcpServers": {
    "kotlin-java-library-sources": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0"
      ]
    }
  }
}
```

2. Refresh the MCP server list in Cascade.

Devin Desktop is the new name for Windsurf.

### Codex

```bash
codex mcp add kotlin-java-library-sources -- docker run -i --rm ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0
```

Or edit `~/.codex/config.toml` directly:

`config.toml`:

```toml
[mcp_servers.kotlin-java-library-sources]
command = "docker"
args = ["run", "-i", "--rm", "ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0"]
```

Needs Docker on your computer.

### Gemini CLI

```bash
gemini mcp add kotlin-java-library-sources docker -- run -i --rm ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0
```

This adds it to the current project. Add `-s user` to use it everywhere.

### Any client

Most clients that start local servers accept this shape:

```json
{
  "mcpServers": {
    "kotlin-java-library-sources": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "ghcr.io/aoreshkov/kotlin-lib-mcp:0.7.0"
      ]
    }
  }
}
```

Zed puts servers under `context_servers` in its settings, with the same `command`, `args` and `env` fields.

Needs Docker on your computer.

## Details

- Server version: 0.7.0
- Last checked: 2026-10-04
- Listed: 2026-10-04
- Updated: 2026-10-04

---
Source: https://mcp.tc/i/kotlin-java-library-sources (mcp.tc is an independent directory, not affiliated with this server's publisher). Corrections: https://mcp.tc/report