CSV to PostgreSQL MCP Server

An MCP (Model Context Protocol) server that loads CSV files into PostgreSQL databases with validation and progress tracking.

Features

• CSV Validation: Validates CSV structure and provides detailed error messages
• Efficient Loading: Uses PostgreSQL COPY command for fast bulk loading
• Progress Tracking: Shows progress bar for long-running imports
• Flexible Configuration: Optional database name (defaults to csvimports)
• Error Reporting: Exact line numbers and column information for validation errors

Installation

From PyPI

pip install csv-postgres-loader

Or using uv:

uv pip install csv-postgres-loader

From Source

Clone the repository and install with uv:

git clone https://github.com/raviramadoss/mcp-csv-postgres.git
cd mcp-csv-postgres
uv sync --all-extras

Usage

As MCP Server

Option 1: After installing from PyPI

Add to your Claude Desktop configuration file (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "csv-postgres-loader": {
      "command": "uv",
      "args": [
        "tool",
        "run",
        "--from",
        "csv-postgres-loader",
        "csv-postgres-loader"
      ]
    }
  }
}

Option 2: For local development

{
  "mcpServers": {
    "csv-postgres-loader": {
      "command": "uv",
      "args": [
        "tool",
        "run",
        "--from",
        "/path/to/mcp-csv-postgres",
        "--python",
        "3.10",
        "csv-postgres-loader"
      ]
    }
  }
}

Or run directly from command line:

csv-postgres-loader

Tool: load_csv_to_postgres

Loads a CSV file into PostgreSQL database.

Parameters:

• file_path (required): Path to the CSV file
• dbname (optional): Database name (default: csvimports)
• host (optional): PostgreSQL host (default: localhost)
• port (optional): PostgreSQL port (default: 5432)
• user (optional): PostgreSQL user (default: postgres)
• password (optional): PostgreSQL password
• table_name (optional): Table name (derived from filename if not provided)

Returns:

• Success message with database name, table name, and rows loaded
• Error message with detailed validation or database errors

Testing the Server

Quick Test

Run the test script to see the server in action:

uv run python test_server.py

This will:

1. Create sample CSV files
2. Test loading them into PostgreSQL
3. Test validation error reporting
4. Show detailed output

Manual Testing with Sample Data

A sample CSV file is provided in sample_data.csv. To test manually:

# In Python/IPython
import asyncio
from csv_postgres_loader.server import call_tool

result = asyncio.run(call_tool(
    "load_csv_to_postgres",
    {"file_path": "sample_data.csv"}
))
print(result[0].text)

Using with MCP Inspector

To test with the MCP Inspector tool:

npx @modelcontextprotocol/inspector uv run csv-postgres-loader

VS Code Launch Configurations

The .vscode/launch.json includes:

• Run MCP Server: Start the server in debug mode
• Test MCP Server with Sample CSV: Run the test script
• Run All Tests: Execute full test suite
• Run Specific Test: Debug a single test file

Development

Running Tests

uv run pytest

Code Coverage

uv run pytest --cov-report=html

Coverage report will be available in htmlcov/index.html.

Current coverage: >90%

Pre-commit Hooks

Pre-commit hooks are configured to run tests before each commit:

uv run pre-commit install
uv run pre-commit run --all-files

Architecture

Modules

• validator.py: CSV validation with detailed error reporting

  • File existence and readability checks
  • CSV structure validation
  • Row consistency validation
  • Automatic dialect detection

• database.py: PostgreSQL database operations

  • Connection management
  • Database creation
  • Table creation from CSV headers
  • Row counting

• loader.py: CSV loading using COPY command

  • Progress tracking with tqdm
  • Efficient bulk loading
  • Error handling and rollback

• server.py: MCP server implementation

  • stdio transport
  • Tool registration
  • Error handling

Error Handling

The server provides detailed error messages:

• Validation Errors: Exact line numbers and description of CSV issues
• Database Errors: Connection, permission, and SQL errors
• File Errors: Permission, encoding, and file not found errors

Examples

Loading a CSV file

{
  "tool": "load_csv_to_postgres",
  "arguments": {
    "file_path": "/path/to/data.csv"
  }
}

With custom database

{
  "tool": "load_csv_to_postgres",
  "arguments": {
    "file_path": "/path/to/data.csv",
    "dbname": "mydb",
    "table_name": "my_table"
  }
}

License

MIT