MinIO MCP Server

A Model Context Protocol (MCP) server that provides a bridge between MCP-compatible clients and MinIO object storage. This server exposes MinIO operations as MCP tools for seamless bucket management and object operations.

Features

• 7 MCP Tools organized by domain for comprehensive MinIO operations:

Bucket Management

• list_buckets: List all available buckets with creation dates
• get_bucket_info: Get detailed bucket information (metadata, policies, object count, total size, encryption)
• create_bucket: Create new buckets with name validation and existence checks
• delete_bucket: Delete buckets (empty only) or force delete with all contents

Object Management

• list_objects: List objects with filtering (prefix, recursive) and configurable limits (default 25)
• get_object_info: Get detailed object metadata (size, content-type, etag, version info, custom metadata)
• delete_object: Delete objects from buckets with optional version support for versioned objects

Key Features

• FastMCP Integration: Built on FastMCP framework for robust MCP protocol support
• Comprehensive Validation: Input validation, error handling with appropriate HTTP status codes (400, 404, 409, 500)
• Async Architecture: Full async/await support for MCP protocol compliance
• Modular Design: Separated concerns with BucketTools and ObjectTools classes
• Extensive Testing: 100% test coverage with advanced mocking techniques
• Standardized Responses: Consistent error handling via TextContent entity

Quick Start

Prerequisites

• Python 3.11 or higher
• MinIO server (local or remote)
• UV package manager (recommended)

Installation

# Clone the repository
git clone <repository-url>
cd minio-mcp-server

# Install dependencies
uv sync

# Install in development mode
uv pip install -e .

Configuration

1. Copy the example environment file:

cp .env.example .env

2. Configure your MinIO connection in .env:

MINIO_ENDPOINT=localhost:9000
MINIO_ACCESS_KEY=minioadmin
MINIO_SECRET_KEY=minioadmin
MINIO_SECURE=false
MINIO_LOG_LEVEL=INFO

Running the Server

# Start the MCP server (stdio transport for Claude Desktop)
uv run python src/minio_mcp/server.py

# Test with MCP Inspector (interactive testing)
uv run mcp src/minio_mcp/server.py

# Alternative: Direct python execution
cd src/minio_mcp
python server.py

Using with Claude Desktop

To connect this MCP server with Claude Desktop:

1. Configure Claude Desktop

Edit your Claude Desktop configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%/Claude/claude_desktop_config.json

Add this configuration (adjust paths for your system):

{
  "mcpServers": {
    "minio-mcp-server": {
      "command": "/Users/your_username/.local/bin/uv",
      "args": [
        "--directory",
        "/path/to/your/minio-mcp-server",
        "run",
        "python",
        "src/minio_mcp/server.py"
      ],
      "env": {
        "MINIO_ENDPOINT": "localhost:9000",
        "MINIO_ACCESS_KEY": "minioadmin",
        "MINIO_SECRET_KEY": "minioadmin",
        "MINIO_SECURE": "false"
      }
    }
  }
}

2. Restart Claude Desktop

After saving the configuration, completely restart Claude Desktop.

3. Test the Connection

Try commands like:

• "List all buckets in MinIO"
• "Show me information about the 'my-bucket' bucket"
• "List the first 10 objects in 'my-bucket'"
• "Get information about 'file.txt' in 'my-bucket'"
• "Delete 'old-file.txt' from 'my-bucket'"

Architecture

Core Components

• FastMCP Server (server.py): Main MCP protocol handler using FastMCP framework
• MinioClient (infrastructure/minio_client.py): Infrastructure layer with MinIO client management and configuration
• BucketTools (tools/bucket_tools.py): Business logic for bucket operations with validation and error handling
• ObjectTools (tools/object_tools.py): Business logic for object operations with comprehensive metadata extraction
• TextContent (tools/entities.py): Standardized response entity for consistent error handling

Data Flow

MCP Client → FastMCP Server → BucketTools/ObjectTools → MinioClient → MinIO Server

Configuration Options

Environment Variable	Description	Default
MINIO_ENDPOINT	MinIO server endpoint	Required
MINIO_ACCESS_KEY	Access key for authentication	Required
MINIO_SECRET_KEY	Secret key for authentication	Required
MINIO_SECURE	Use HTTPS (true/false)	true
MINIO_LOG_LEVEL	Logging level (DEBUG/INFO/WARNING/ERROR)	INFO
MINIO_MAX_OBJECTS_LIST	Maximum objects per list operation	25

Development

Setting up a Test MinIO Server

docker run -p 9000:9000 -p 9001:9001 \
  --name minio-test \
  -e "MINIO_ROOT_USER=minioadmin" \
  -e "MINIO_ROOT_PASSWORD=minioadmin" \
  quay.io/minio/minio server /data --console-address ":9001"

Running Tests

# Run all tests
uv run pytest

# Run with coverage report
uv run pytest --cov=src/minio_mcp --cov-report=html

# Run specific test files
uv run pytest tests/tools/test_bucket_tools.py -v
uv run pytest tests/tools/test_object_tools.py -v
uv run pytest tests/infrastructure/test_minio_client.py -v

# Test specific functionality
uv run pytest -k "test_create_bucket" -v

Code Quality

# Lint and format check
uv run ruff check src tests

# Auto-format code
uv run ruff format src tests

# Type checking
uv run mypy src

License

[Add your license here]

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests for new functionality
5. Ensure all tests pass and code quality checks succeed
6. Submit a pull request

Support

For issues and questions, please check the documentation or open an issue in the repository.