Custom MCP Database

🚀 MCP Database Server

This project offers a Middleware/Control Plane (MCP) server. It enables code agents (such as Gemini, Claude Desktop, and Claude Code) to securely execute queries on various databases (PostgreSQL, MySQL, MongoDB, Oracle) without directly exposing credentials. Database connection configurations are managed in an SQLite database (mcp_config.sqlite3).

🚀 Quick Start

Prerequisites

Before you start, make sure you have the necessary environment and tools installed, such as git, Python, and make.

Installation

To set up the project, follow these steps:

1. Clone the repository (if you haven't already):

   git clone <repository_url>
   cd custom-mcp-database
   

2. Install dependencies: This project uses a venv (virtual environment) to manage dependencies. Run the following command to create the virtual environment and install the required Python packages:

   make install
   

   This will create a venv/ directory and install everything listed in requirements.txt.

Running the MCP Server

To start the MCP server, use the make run command:

make run

The server will start and listen for incoming requests from your code agents.

✨ Features

• Secure Query Execution: Allows code agents to execute queries on multiple databases without exposing credentials.
• Multiple Database Support: Supports PostgreSQL, MySQL, MongoDB, and Oracle.
• Easy Configuration Management: Manages database connections in an SQLite database.

📦 Installation

Cloning the Repository

git clone <repository_url>
cd custom-mcp-database

Installing Dependencies

make install

💻 Usage Examples

Database Configuration

Adding a Database Connection

General Syntax (Global Command - Recommended):

mcp-db add-db --alias <alias> --type <type> [connection_parameters]

Alternative (Local Command):

python main.py add-db --alias <alias> --type <type> [connection_parameters]

Examples (Global Command):

• PostgreSQL:

  mcp-db add-db --alias pg_dev --type postgres --host localhost --port 5432 --user myuser --password mypassword --dbname mydb
  

• MySQL:

  mcp-db add-db --alias mysql_prod --type mysql --host 192.168.1.10 --port 3306 --user root --password secret --dbname production_db
  

• Oracle:

  mcp-db add-db --alias oracle_test --type oracle --host oracle.example.com --port 1521 --user system --password oraclepass --dbname ORCLPDB1
  

• MongoDB:

  mcp-db add-db --alias mongo_cluster --type mongo --uri "mongodb+srv://user:pass@cluster.mongodb.net/" --dbname myapp_db
  

Removing a Database Connection

Global Command:

mcp-db remove-db --alias <alias>

Local Command:

python main.py remove-db --alias <alias>

Example:

mcp-db remove-db --alias pg_dev

Getting Help

mcp-db --help
mcp-db execute-query --help

Integration with Code Agents

Gemini

Once the MCP server is running (make run), Gemini will automatically discover and make the following tools available for interacting with your configured databases:

• list_aliases(): Lists all configured database aliases.
• add_database(...): Adds a new database connection.
• remove_database(...): Removes a database connection.
• execute_query(database_alias, query, params, schema): Executes a query against a configured database.

Gemini Usage Examples:

• List aliases:

  list_aliases()
  

• Execute a SQL query (PostgreSQL/MySQL/Oracle):

  execute_query(database_alias="pg_dev", query="SELECT * FROM users WHERE id = %s;", params={"id": 1})
  

• Execute a MongoDB query:

  execute_query(database_alias="mongo_cluster", query='''{"name": "John Doe"}''', params={"collection": "users"})
  

Claude Desktop

To integrate with Claude Desktop, you need to configure its claude_desktop_config.json file to point to your MCP server. Create or modify this file (usually located in your Claude Desktop configuration directory) with an entry similar to this:

{
  "mcpServers": {
    "Custom DB Server": {
      "command": "/your-path-to/custom-mcp-database/venv/bin/python",
      "args": [
        "/your-path-to/custom-mcp-database/main.py"
      ],
      "workingDirectory": "/your-path-to/custom-mcp-database"
    }
  }
}

Important: Replace /your-path-to/custom-mcp-database with the actual absolute path to your custom-mcp-database directory.

After configuring, restart Claude Desktop. The MCP tools will then be available for use within Claude Desktop.

Tool Configuration for AI Agents

To enable AI agents like Claude Code and Gemini to automatically discover and utilize the MCP server's tools, you need to configure them to launch or connect to the MCP server. This typically involves providing the path to the main.py script and specifying the working directory.

Here are examples of how you might configure your AI agent's mcpServers section:

For Claude Code

{
  "mcpServers": {
    "Custom DB Server": {
      "command": "/your-path-to/custom-mcp-database/venv/bin/python",
      "args": [
        "/your-path-to/custom-mcp-database/main.py"
      ],
      "workingDirectory": "/your-path-to/custom-mcp-database"
    }
  }
}

For Gemini

{
  "mcpServers": {
    "Custom DB Server": {
      "command": "/your-path-to/custom-mcp-database/venv/bin/python",
      "args": [
        "/your-path-to/custom-mcp-database/main.py"
      ],
      "workingDirectory": "/your-path-to/custom-mcp-database"
    }
  }
}

Important: Replace /your-path-to/custom-mcp-database with the actual absolute path to your custom-mcp-database directory.

Refer to your specific AI agent's official documentation for the most accurate and up-to-date instructions on configuring external MCP servers.

📚 Documentation

Database Configuration

• Adding a Database Connection: Use the add-db command with the appropriate parameters for each database type.
• Removing a Database Connection: Use the remove-db command with the alias of the connection you want to remove.
• Getting Help: Use the --help option for detailed information.

Integration with Code Agents

• Gemini: Automatically discovers the MCP server and provides tools for database interaction.
• Claude Desktop: Configure the claude_desktop_config.json file to point to the MCP server.
• AI Agents: Configure the mcpServers section in the agent's configuration file.

🔧 Technical Details

• Middleware/Control Plane (MCP) Server: Manages database connections and query execution.
• SQLite Database: Stores database connection configurations.
• Code Agents: Interact with the MCP server to execute queries on databases.

📄 License

No license information is provided in the original README. If there is a license, it should be added here.