RustFS MCP Server - Model Context Protocol

📖 Overview

RustFS MCP Server is a high-performance Model Context Protocol (MCP) server that provides AI/LLM tools with seamless access to S3-compatible object storage operations. Built with Rust for maximum performance and safety, it enables AI assistants like Claude Desktop to interact with cloud storage through a standardized protocol.

What is MCP?

The Model Context Protocol is an open standard that enables secure, controlled connections between AI applications and external systems. This server acts as a bridge between AI tools and S3-compatible storage services, providing structured access to file operations while maintaining security and observability.

✨ Features

Supported S3 Operations

• List Buckets: List all accessible S3 buckets
• List Objects: Browse bucket contents with optional prefix filtering
• Upload Files: Upload local files with automatic MIME type detection and cache control
• Get Objects: Retrieve objects from S3 storage with read or download modes
• Create Bucket: Create a new S3 bucket with the specified name
• Delete Bucket: Delete an existing, empty S3 bucket

🔧 Installation

Prerequisites

• Rust 1.85+ (for building from source, Rust edition 2024)
• AWS credentials configured (via environment variables, AWS CLI, or IAM roles)
• Access to S3-compatible storage service

Build from Source

# Clone the repository
git clone https://github.com/rustfs/rustfs.git
cd rustfs

# Build the MCP server
cargo build --release -p rustfs-mcp

# The binary will be available at
./target/release/rustfs-mcp

Optional: Enable io-uring

io-uring is enabled by default in this crate. Tokio requires unstable cfg for this mode:

RUSTFLAGS="--cfg tokio_unstable" cargo build --release -p rustfs-mcp

To explicitly disable it:

cargo build --release -p rustfs-mcp --no-default-features

⚙️ Configuration

Environment Variables

# AWS Credentials (required)
export AWS_ACCESS_KEY_ID=your_access_key
export AWS_SECRET_ACCESS_KEY=your_secret_key
export AWS_REGION=us-east-1  # Optional, defaults to us-east-1

# Optional: Custom S3 endpoint (for MinIO, etc.)
export AWS_ENDPOINT_URL=http://localhost:9000

# Logging level (optional)
export RUST_LOG=info

Command Line Options

rustfs-mcp --help

The server supports various command-line options for customizing behavior:

• --access-key-id: AWS Access Key ID for S3 authentication
• --secret-access-key: AWS Secret Access Key for S3 authentication
• --region: AWS region to use for S3 operations (default: us-east-1)
• --endpoint-url: Custom S3 endpoint URL (for MinIO, LocalStack, etc.)
• --force-path-style: Force path-style S3 addressing (automatically enabled for custom endpoints)
• --log-level: Log level configuration (default: rustfs_mcp_server=info)

🚀 Usage

Starting the Server

# Start the MCP server
rustfs-mcp

# Or with custom options
rustfs-mcp --log-level debug --region us-west-2

Integration with chat client

Option 1: Using Command Line Arguments

{
  "mcpServers": {
    "rustfs-mcp": {
      "command": "/path/to/rustfs-mcp",
      "args": [
        "--endpoint-url", "your_url",
        "--access-key-id", "your_access_key",
        "--secret-access-key", "your_secret_key",
        "--region", "us-west-2",
        "--log-level", "info"
      ]
    }
  }
}

Option 2: Using Environment Variables

{
  "mcpServers": {
    "rustfs-mcp": {
      "command": "/path/to/rustfs-mcp",
      "env": {
        "AWS_ENDPOINT_URL": "your_url",
        "AWS_ACCESS_KEY_ID": "your_access_key",
        "AWS_SECRET_ACCESS_KEY": "your_secret_key",
        "AWS_REGION": "us-east-1"
      }
    }
  }
}

Using MCP with Docker

Docker image build

Using MCP with docker will simplify the usage of rustfs mcp. Building the docker image with below command:

docker build -f Dockerfile -t rustfs/rustfs-mcp ../../

Alternatively, if you want to build the image from the rustfs codebase root directory, run the command:

docker build -f crates/mcp/Dockerfile -t rustfs/rustfs-mcp .

IDE Configuration

Adding the following content in IDE MCP settings:

{
  "mcpServers": {
    "rustfs-mcp": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "-e",
        "AWS_ACCESS_KEY_ID",
        "-e",
        "AWS_SECRET_ACCESS_KEY",
        "-e",
        "AWS_REGION",
        "-e",
        "AWS_ENDPOINT_URL",
        "rustfs/rustfs-mcp"
      ],
      "env": {
        "AWS_ACCESS_KEY_ID": "rustfs_access_key",
        "AWS_SECRET_ACCESS_KEY": "rustfs_secret_key",
        "AWS_REGION": "cn-east-1",
        "AWS_ENDPOINT_URL": "rustfs_instance_url"
      }
    }
  }
}

If success, MCP configure page will show the available tools.

🛠️ Available Tools

The MCP server exposes the following tools that AI assistants can use:

list_buckets

List all S3 buckets accessible with the configured credentials.

Parameters: None

list_objects

List objects in an S3 bucket with optional prefix filtering.

Parameters:

• bucket_name (string): Name of the S3 bucket
• prefix (string, optional): Prefix to filter objects

upload_file

Upload a local file to S3 with automatic MIME type detection.

Parameters:

• local_file_path (string): Path to the local file
• bucket_name (string): Target S3 bucket
• object_key (string): S3 object key (destination path)
• content_type (string, optional): Content type (auto-detected if not provided)
• storage_class (string, optional): S3 storage class
• cache_control (string, optional): Cache control header

get_object

Retrieve an object from S3 with two operation modes: read content directly or download to a file.

Parameters:

• bucket_name (string): Source S3 bucket
• object_key (string): S3 object key
• version_id (string, optional): Version ID for versioned objects
• mode (string, optional): Operation mode - "read" (default) returns content directly, "download" saves to local file
• local_path (string, optional): Local file path (required when mode is "download")
• max_content_size (number, optional): Maximum content size in bytes for read mode (default: 1MB)

create_bucket

Create a new S3 bucket with the specified name.

Parameters:

• bucket_name (string): Name of the S3 bucket to create

delete_bucket

Delete an existing S3 bucket with the specified name. If the bucket is not empty, the deletion will fail — delete all objects (and their versions) in the bucket before calling this tool.

WARNING: This operation will permanently delete the bucket!

Parameters:

• bucket_name (string): Name of the S3 bucket to delete

Architecture

The MCP server is built with a modular architecture:

rustfs-mcp/
├── src/
│   ├── main.rs          # Entry point, CLI parsing, and server initialization
│   ├── server.rs        # MCP server implementation and tool handlers
│   ├── s3_client.rs     # S3 client wrapper with async operations
│   ├── config.rs        # Configuration management and CLI options
│   └── lib.rs           # Library exports and public API
└── Cargo.toml           # Dependencies, metadata, and binary configuration