Hue Server

An MCP (Model Context Protocol) server that exposes HueClientRest functionality, allowing AI assistants to interact with Hadoop Hue for executing SQL queries and managing HDFS files.

What is This?

This server enables AI assistants (like GitHub Copilot, Claude Desktop, or other MCP-compatible clients) to:

• Execute SQL queries on Hadoop Hue using Hive, SparkSQL, or Impala
• Manage HDFS files (list, upload, download)
• Export query results to CSV files
• Browse and manage directory structures

The Model Context Protocol (MCP) is an open standard for connecting AI assistants to external tools and data sources, making them more powerful and context-aware.

Features

• SQL Query Execution: Execute queries using Hive, SparkSQL, or Impala dialects
• Result Export: Save query results to CSV files with automatic retry on large datasets
• HDFS Operations: List, upload, and download files from HDFS
• Directory Management: Check directory existence and browse file structures
• Robust Error Handling: Built-in retry mechanisms and detailed error reporting

Prerequisites

Before installing this MCP server, you need:

1. Python 3.10 or higher - Download Python
2. Astral uv - Fast Python package installer and environment manager
3. Visual Studio Code - For MCP integration with GitHub Copilot
4. GitHub Copilot subscription - Required for VS Code MCP integration
5. Access to a Hadoop Hue server - You'll need the host URL, username, and password

Dependencies

This project uses the following key dependencies:

• Astral uv - An extremely fast Python package and project manager, written in Rust. It's 10-100x faster than pip and handles dependency resolution much better.
• mcp[cli] - The official Python SDK for the Model Context Protocol, including CLI tools
• hueclientrest - Python client library for interacting with Hadoop Hue REST API
• pydantic - Data validation using Python type annotations

Installation

Step 1: Install Astral uv

uv is a modern, fast Python package manager that we use for dependency management.

On Windows (PowerShell):

powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"

On macOS/Linux:

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

After installation, restart your terminal or add uv to your PATH as instructed by the installer.

Verify installation:

uv --version

Step 2: Clone and Install the Project

# Clone the repository
git clone <your-repo-url>
cd hueclientrest-mpc

# Install dependencies and create virtual environment
uv sync

The uv sync command will:

• Create a virtual environment (.venv)
• Install all dependencies from pyproject.toml
• Set up the project for development

Alternative: Using pip

If you prefer pip over uv:

pip install -e .

However, uv is strongly recommended for better performance and dependency management.

Configuration

Environment Variables

The server requires the following environment variables to connect to your Hue server:

Variable	Required	Description
HUE_HOST	Yes	Hue server URL (e.g., https://hue.example.com)
HUE_USERNAME	Yes	Username for Hue authentication
HUE_PASSWORD	Yes	Password for Hue authentication
HUE_VERIFY_SSL	No	Verify SSL certificates (default: true)
HUE_SSL_WARNINGS	No	Show SSL warnings (default: false)

Setting Up Environment Variables

Option 1: Using .env file (Recommended for local development)

# Create a .env file in the project root
HUE_HOST=https://your-hue-server.com
HUE_USERNAME=your_username
HUE_PASSWORD=your_password
HUE_VERIFY_SSL=true
HUE_SSL_WARNINGS=false

Option 2: System environment variables

On Windows (PowerShell):

$env:HUE_HOST="https://your-hue-server.com"
$env:HUE_USERNAME="your_username"
$env:HUE_PASSWORD="your_password"

On macOS/Linux:

export HUE_HOST="https://your-hue-server.com"
export HUE_USERNAME="your_username"
export HUE_PASSWORD="your_password"

VS Code Integration with GitHub Copilot

Prerequisites for VS Code Integration

1. Visual Studio Code - Download VS Code
2. GitHub Copilot extension - Install from VS Code marketplace
3. GitHub Copilot subscription - Required for MCP support
4. This MCP server installed and configured

Step 1: Locate Your MCP Configuration File

The MCP configuration file location depends on your operating system:

• Windows: %APPDATA%\Code\User\mcp.json
  • Full path: C:\Users\<YourUsername>\AppData\Roaming\Code\User\mcp.json
• macOS: ~/Library/Application Support/Code/User/mcp.json
• Linux: ~/.config/Code/User/mcp.json

If the file doesn't exist, create it.

Step 2: Configure the MCP Server in VS Code

Add the following configuration to your mcp.json file:

{
  "mcpServers": {
    "hue": {
      "command": "uv",
      "args": [
        "run",
        "--directory",
        "C:\\Projects\\hueclientrest-mpc",
        "hue-mcp-server"
      ],
      "env": {
        "HUE_HOST": "https://your-hue-server.com",
        "HUE_USERNAME": "your_username",
        "HUE_PASSWORD": "your_password",
        "HUE_VERIFY_SSL": "true",
        "HUE_SSL_WARNINGS": "false"
      }
    }
  }
}

Important Notes:

• Replace C:\\Projects\\hueclientrest-mpc with the actual path to your project
• On Windows, use double backslashes (\\) or forward slashes (/) in paths
• Replace the environment variable values with your actual Hue credentials
• The command is uv which will use the uv package manager to run the server

Step 3: Verify the Configuration

1. Restart VS Code completely (close all windows)
2. Open GitHub Copilot Chat (Ctrl+Shift+I or Cmd+Shift+I)
3. Check for the Hue MCP tools: Type @workspace and look for Hue-related capabilities
4. Test the connection: Ask Copilot to "list files in HDFS directory /user"

Step 4: Using the MCP Server with Copilot

Once configured, you can ask GitHub Copilot to interact with your Hue server:

Example queries:

• "Execute a Hive query to show tables"
• "List files in HDFS directory /user/data"
• "Download the file /user/data/results.csv from HDFS"
• "Execute this SQL query and save results to CSV: SELECT * FROM my_table LIMIT 100"

Troubleshooting VS Code Integration

Issue: MCP server not appearing in Copilot

• Verify the mcp.json path is correct
• Check that uv is installed and in your PATH
• Restart VS Code completely
• Check VS Code's Output panel (View > Output) and select "GitHub Copilot" from the dropdown

Issue: Authentication errors

• Verify your HUE_HOST, HUE_USERNAME, and HUE_PASSWORD are correct
• Test connectivity to your Hue server directly
• Check if SSL verification is causing issues (try setting HUE_VERIFY_SSL to false for testing)

Issue: Command not found

• Ensure uv is installed: run uv --version in terminal
• Verify the project path in mcp.json is correct and uses proper escaping
• Make sure you ran uv sync in the project directory

Alternative: Using Absolute Python Path

If uv is not working or not in your PATH, you can use the absolute path to the Python interpreter:

Windows example:

{
  "mcpServers": {
    "hue": {
      "command": "C:\\Projects\\hueclientrest-mpc\\.venv\\Scripts\\python.exe",
      "args": ["-m", "hue_mcp_server.server"],
      "env": {
        "HUE_HOST": "https://your-hue-server.com",
        "HUE_USERNAME": "your_username",
        "HUE_PASSWORD": "your_password"
      }
    }
  }
}

macOS/Linux example:

{
  "mcpServers": {
    "hue": {
      "command": "/full/path/to/hueclientrest-mpc/.venv/bin/python",
      "args": ["-m", "hue_mcp_server.server"],
      "env": {
        "HUE_HOST": "https://your-hue-server.com",
        "HUE_USERNAME": "your_username",
        "HUE_PASSWORD": "your_password"
      }
    }
  }
}

Other Usage Methods

Claude Desktop Integration

If you're using Claude Desktop instead of VS Code, add this to your Claude config (~/.config/claude/claude_desktop_config.json on Mac/Linux or %APPDATA%\Claude\claude_desktop_config.json on Windows):

{
  "mcpServers": {
    "hue": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/hueclientrest-mpc", "hue-mcp-server"],
      "env": {
        "HUE_HOST": "https://your-hue-server.com",
        "HUE_USERNAME": "your_username",
        "HUE_PASSWORD": "your_password"
      }
    }
  }
}

Development Mode

Test the server interactively using the MCP inspector:

uv run mcp dev src/hue_mcp_server/server.py

This opens an interactive interface where you can test tools and see requests/responses in real-time.

Direct Command Line Execution

You can also run the server directly:

# Using the installed script (after uv sync)
uv run hue-mcp-server

# Or via Python module
uv run python -m hue_mcp_server.server

Available Tools

SQL Query Tools

hue_execute_query

Execute a SQL query and return results directly.

Arguments:
  - statement: SQL statement to execute
  - dialect: 'hive', 'sparksql', or 'impala' (default: 'hive')
  - timeout: Max wait time in seconds (default: 300)
  - batch_size: Rows per batch (default: 1000)

hue_run_query_to_csv

Execute a query and save results to a CSV file.

Arguments:
  - statement: SQL statement to execute
  - filename: Output CSV filename (default: 'results.csv')
  - dialect: SQL dialect (default: 'hive')
  - batch_size: Rows per batch (default: 1000)

hue_export_and_download

Execute INSERT OVERWRITE DIRECTORY and download resulting files.

Arguments:
  - statement: SQL with INSERT OVERWRITE DIRECTORY
  - hdfs_directory: HDFS output directory
  - local_directory: Local download directory (default: '.')
  - dialect: SQL dialect (default: 'hive')
  - file_pattern: Regex to filter files (optional)
  - timeout: Max wait time (default: 300)

HDFS File Tools

hue_list_directory

List contents of an HDFS directory.

Arguments:
  - directory_path: HDFS path (e.g., '/user/data')
  - page_size: Max items to return (default: 1000)

hue_check_directory_exists

Check if an HDFS directory exists.

Arguments:
  - directory_path: HDFS path to check

hue_download_file

Download a single file from HDFS.

Arguments:
  - remote_path: Full HDFS file path
  - local_filename: Local filename (optional)

hue_download_directory

Download all files from an HDFS directory.

Arguments:
  - directory_path: HDFS directory path
  - local_directory: Local directory (default: '.')
  - file_pattern: Regex to filter files (optional)

hue_upload_file

Upload a local file to HDFS.

Arguments:
  - local_file_path: Path to local file
  - hdfs_destination: HDFS destination directory

How It Works

The Model Context Protocol (MCP)

MCP is an open protocol that standardizes how AI assistants communicate with external tools and data sources. Think of it as a universal adapter that lets AI assistants "plug into" different services.

Key components:

• MCP Server (this project): Exposes tools and capabilities
• MCP Client (VS Code/Claude Desktop): Consumes tools and presents them to the AI
• Protocol: Defines how they communicate

Architecture Flow

┌─────────────────┐        ┌──────────────────┐        ┌─────────────────┐
│   GitHub        │  MCP   │   Hue MCP        │  REST  │   Hadoop Hue    │
│   Copilot       │◄──────►│   Server         │◄──────►│   Server        │
│   (VS Code)     │Protocol│   (This Project) │  API   │                 │
└─────────────────┘        └──────────────────┘        └─────────────────┘
                                     │
                                     ▼
                           ┌──────────────────┐
                           │  HueClientRest   │
                           │  Library         │
                           └──────────────────┘

1. User asks Copilot to query Hue data
2. Copilot recognizes the request requires Hue MCP tools
3. MCP Server receives the request and translates it to Hue REST API calls
4. HueClientRest library handles authentication and API communication
5. Results flow back through the chain to the user

Dependency Details

Astral uv (Package Manager)

What it is: A next-generation Python package and project manager written in Rust.

Why we use it:

• Speed: 10-100x faster than pip
• Better dependency resolution: Handles complex dependencies more reliably
• Unified tool: Combines pip, pip-tools, pipx, poetry, pyenv functionality
• Reproducible environments: Lock files ensure consistent installs
• Cross-platform: Works seamlessly on Windows, macOS, and Linux

Key commands:

• uv sync - Install/update dependencies
• uv add <package> - Add a new dependency
• uv run <command> - Run commands in the virtual environment
• uv pip install <package> - Use like pip if needed

Learn more: https://docs.astral.sh/uv/

mcp[cli] (Python SDK)

What it is: The official Python SDK for building MCP servers.

Key features:

• FastMCP framework: Simplified server creation with decorators
• Type validation: Pydantic integration for request/response validation
• CLI tools: mcp dev for testing, mcp install for setup
• Async support: Built on asyncio for efficient I/O
• SSE transport: Server-sent events for real-time communication

In this project:

from mcp.server.fastmcp import FastMCP

mcp = FastMCP("Hue MCP Server")

@mcp.tool()
def hue_execute_query(statement: str, dialect: str = "hive"):
    """Execute SQL query on Hue"""
    # Implementation

hueclientrest (Hue Client Library)

What it is: Python client for Hadoop Hue REST API.

Capabilities:

• SQL query execution (Hive, SparkSQL, Impala)
• HDFS file operations
• Session management
• Authentication handling
• Error handling and retries

In this project:

from hueclientrest import HueClientREST

client = HueClientREST(host, username, password)
client.login()
result = client.execute_query(statement, dialect)

pydantic (Data Validation)

What it is: Data validation library using Python type hints.

Why we use it:

• Type safety: Validates tool inputs/outputs at runtime
• Auto-documentation: Generates schemas from type hints
• Error messages: Clear validation errors for debugging
• JSON schema: Automatic schema generation for MCP

In this project:

from pydantic import BaseModel, Field

class QueryResult(BaseModel):
    rows: List[dict]
    columns: List[str]
    row_count: int

Example Usage Scenarios

Scenario 1: Execute a Hive Query

In VS Code with Copilot:

You: "Execute a Hive query to show the first 10 tables"
Copilot: [Uses hue_execute_query tool]
Result: Returns table list from your Hue server

Query executed:

SELECT database_name, table_name 
FROM information_schema.tables 
LIMIT 10

Scenario 2: List HDFS Files

In VS Code with Copilot:

You: "List all files in /user/hive/warehouse directory"
Copilot: [Uses hue_list_directory tool]
Result: Shows file names, sizes, and permissions

Scenario 3: Export Data to CSV

In VS Code with Copilot:

You: "Query the sales table for 2024 and save to CSV"
Copilot: [Uses hue_run_query_to_csv tool]
Result: Creates sales_2024.csv with query results

Query executed:

SELECT * FROM sales WHERE year = 2024

Scenario 4: Complex Data Pipeline

In VS Code with Copilot:

You: "Check if /user/data/processed exists, if not list /user/data, 
     then download all CSV files from there"
Copilot: 
  1. [Uses hue_check_directory_exists]
  2. [Uses hue_list_directory]
  3. [Uses hue_download_directory with file_pattern=".*\.csv$"]
Result: Downloads all CSV files to local directory

Development

Setting Up for Development

# Clone and install
git clone <your-repo-url>
cd hueclientrest-mpc
uv sync

# Install development dependencies
uv sync --dev

Running Tests

# Run all tests
uv run pytest

# Run with coverage
uv run pytest --cov=hue_mcp_server

# Run specific test file
uv run pytest tests/test_server.py

Adding New Tools

To add a new MCP tool:

1. Define the tool function in server.py:

@mcp.tool()
def hue_new_feature(param: str) -> dict:
    """Description of what this tool does."""
    client = get_client()
    result = client.some_operation(param)
    return {"status": "success", "data": result}

2. The @mcp.tool() decorator automatically:

   • Registers the tool with the MCP server
   • Generates JSON schema from type hints
   • Validates inputs using Pydantic
   • Handles errors and responses

3. Test your tool:

uv run mcp dev src/hue_mcp_server/server.py

Debugging

Enable verbose logging:

import logging
logging.basicConfig(level=logging.DEBUG)

Test MCP server directly:

# Interactive testing
uv run mcp dev src/hue_mcp_server/server.py

# Check server can start
uv run python -m hue_mcp_server.server

VS Code debugging:

1. Check Output panel: View > Output > GitHub Copilot
2. Look for MCP server connection messages
3. Check for authentication or network errors

Project Structure

hueclientrest-mpc/
├── .venv/                  # Virtual environment (created by uv)
├── pyproject.toml          # Project metadata and dependencies
├── README.md               # This comprehensive guide
├── .env.example            # Example environment variables
├── .gitignore              # Git ignore patterns
└── src/
    └── hue_mcp_server/
        ├── __init__.py     # Package initialization
        └── server.py       # MCP server implementation
            ├── Server setup and configuration
            ├── Tool definitions (@mcp.tool decorators)
            ├── Hue client wrapper functions
            └── Main entry point

Dependencies Management

View installed packages:

uv pip list

Add a new dependency:

uv add <package-name>

Update dependencies:

uv sync --upgrade

Remove a dependency:

uv remove <package-name>

Security Considerations

Credential Management

Best Practices:

1. Never commit credentials to version control
2. Use environment variables or secure vaults
3. Rotate passwords regularly
4. Use .env files for local development only
5. Use secrets management (Azure Key Vault, AWS Secrets Manager) in production

SSL/TLS Configuration

For production environments:

# Always verify SSL certificates
HUE_VERIFY_SSL=true
HUE_SSL_WARNINGS=false

For development/testing (self-signed certificates):

# Only for development!
HUE_VERIFY_SSL=false
HUE_SSL_WARNINGS=false

Network Security

• Ensure Hue server is accessible from your development machine
• Check firewall rules if connection fails
• Use VPN if required by your organization
• Keep authentication tokens secure

Troubleshooting Common Issues

Issue: uv command not found

Solution:

# Windows PowerShell
powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"

# Then restart terminal or add to PATH

Issue: Python version mismatch

Error: requires-python = ">=3.10" but you have Python 3.9

Solution:

# Install Python 3.10+ from python.org
# Or use uv to manage Python versions
uv python install 3.11
uv venv --python 3.11

Issue: MCP server not loading in VS Code

Checklist:

• uv is installed and in PATH (uv --version)
• Project dependencies installed (uv sync)
• mcp.json path is correct for your OS
• Project path in mcp.json uses proper escaping
• VS Code completely restarted (all windows closed)
• GitHub Copilot extension is enabled
• Active Copilot subscription

Issue: Authentication failures

Error: "Authentication failed" or "401 Unauthorized"

Solution:

1. Verify credentials are correct
2. Check if Hue server URL is accessible
3. Test login directly in browser
4. Check for special characters in password (may need escaping)
5. Verify user has necessary permissions in Hue

Issue: Query timeouts

Error: "Query execution timeout"

Solution:

# Increase timeout when calling tools
hue_execute_query(
    statement="SELECT * FROM large_table",
    timeout=600  # 10 minutes instead of default 5
)

Issue: HDFS file not found

Error: "File or directory not found"

Solution:

1. Verify path is absolute (starts with /)
2. Check permissions on HDFS
3. Use hue_list_directory to browse available paths
4. Verify user has read/write permissions

Performance Tips

Query Optimization

1. Use batch_size for large result sets:

hue_execute_query(statement="...", batch_size=5000)

2. Use LIMIT in queries when exploring:

SELECT * FROM large_table LIMIT 1000

3. Export large datasets directly to HDFS:

INSERT OVERWRITE DIRECTORY '/tmp/export'
SELECT * FROM large_table

Then use hue_export_and_download to retrieve files.

HDFS Operations

1. Download specific files with patterns:

hue_download_directory(
    directory_path="/user/data",
    file_pattern=".*\\.csv$"  # Only CSV files
)

2. Use streaming for large file transfers
3. Batch uploads when possible

FAQ

Q: Can I use this with Claude Desktop?

A: Yes! See the "Claude Desktop Integration" section for configuration details.

Q: Does this work on Windows?

A: Yes, fully supported on Windows, macOS, and Linux.

Q: What Hue versions are supported?

A: Any version with REST API support. Tested with Hue 4.x and newer.

Q: Can multiple users share one MCP server?

A: Each user should run their own MCP server instance with their own credentials.

Q: How do I update to the latest version?

A:

git pull
uv sync --upgrade

Q: Is my password secure?

A: Credentials are stored in environment variables or mcp.json. Keep these files secure and never commit them to version control.

Resources

Documentation

• Model Context Protocol Specification
• MCP Python SDK Documentation
• Astral uv Documentation
• HueClientRest Repository
• Pydantic Documentation

Community

• MCP Discord Server
• GitHub Discussions

Related Projects

• MCP Servers Collection
• Awesome MCP

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

Development Setup

git clone <your-repo-url>
cd hueclientrest-mpc
uv sync --dev

Running Tests

uv run pytest
uv run pytest --cov=hue_mcp_server

Code Style

This project uses:

• Black for code formatting
• isort for import sorting
• mypy for type checking

Changelog

v0.1.0 (Current)

• Initial release
• SQL query execution (Hive, SparkSQL, Impala)
• HDFS file operations
• CSV export functionality
• VS Code and Claude Desktop integration

License

MIT License - See LICENSE file for details

Credits

• HueClientRest - The underlying Python client for Hue REST API
• Model Context Protocol - Open standard for AI-tool integration
• Astral - Creators of uv package manager
• Anthropic - MCP specification and implementation

Support

For issues, questions, or feature requests:

1. Check the Troubleshooting section
2. Search existing GitHub issues
3. Create a new issue with detailed information

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Happy querying! 🚀