What is Dax Formatter Mcp

dax-formatter-mcp is an MCP Server that utilizes SQLBI’s DAX Formatter service to provide advanced DAX (Data Analysis Expressions) formatting capabilities for AI assistants and other MCP clients.

Use cases

Use cases include formatting DAX expressions for Power BI reports, optimizing DAX code for performance, and integrating DAX formatting capabilities into AI-driven analytics applications.

How to use

To use dax-formatter-mcp, install the .NET 8.0 Runtime, ensure an internet connection, and set up an MCP-compatible client. You can either download the latest release or build from source using the provided commands.

Key features

Key features include single DAX expression formatting, batch processing of multiple expressions, comprehensive formatting options, robust error handling, fallback mechanisms for failed batch processing, and support for database context.

Where to use

dax-formatter-mcp can be used in data analysis, business intelligence applications, and any environment where DAX expressions are utilized, particularly in conjunction with AI tools.

DAX Formatter MCP Server

A Model Context Protocol (MCP) server that provides DAX (Data Analysis Expressions) formatting capabilities to AI assistants and other MCP clients. This server integrates with the official DAX Formatter service by SQLBI to deliver professional-grade DAX code formatting.

🚀 Features

• Single DAX Expression Formatting: Format individual DAX expressions with professional standards
• Batch Processing: Format multiple DAX expressions in a single efficient request
• Comprehensive Formatting Options: Control line length, spacing, separators, and more
• Error Handling: Robust error handling with detailed error messages
• Fallback Mechanisms: Automatic fallback to individual formatting if batch processing fails
• Database Context: Support for database and server context (anonymized for privacy)

📋 Prerequisites

• .NET 8.0 Runtime or higher
• Internet connection (communicates with daxformatter.com)
• MCP-compatible client (Claude Desktop, Continue, or custom MCP client)

🛠️ Installation

Option 1: Download Release (Recommended)

1. Download the latest release from the Releases page
2. Extract the archive to your preferred location
3. Note the path to the executable for configuration

Option 2: Build from Source

# Clone the repository
git clone https://github.com/EmanueleMeazzo/dax-formatter-mcp.git
cd dax-formatter-mcp

# Build the project
dotnet build --configuration Release

# The executable will be in bin/Release/net8.0/

⚙️ Configuration

Claude Desktop

Add the following to your Claude Desktop configuration file:

Windows: %APPDATA%\Claude\claude_desktop_config.json
macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Linux: ~/.config/claude/claude_desktop_config.json

{
  "mcpServers": {
    "dax-formatter": {
      "command": "path/to/dax-formatter-mcp.exe",
      "args": []
    }
  }
}

Continue IDE Extension

Add to your Continue configuration:

{
  "mcpServers": [
    {
      "name": "dax-formatter",
      "command": "path/to/dax-formatter-mcp.exe",
      "args": []
    }
  ]
}

Generic MCP Client

For any MCP client supporting the MCP 2024-11-05 protocol:

{
  "servers": [
    {
      "name": "dax-formatter",
      "transport": {
        "type": "stdio",
        "command": "path/to/dax-formatter-mcp.exe",
        "args": []
      }
    }
  ]
}

Using with .NET Runtime

If you prefer to use the DLL with the .NET runtime:

{
  "mcpServers": {
    "dax-formatter": {
      "command": "dotnet",
      "args": [
        "path/to/dax-formatter-mcp.dll"
      ]
    }
  }
}

📖 Usage

Once configured, you can use the DAX formatter through your MCP client:

Basic Usage

Format this DAX expression:
CALCULATE(SUM(Sales[Amount]),FILTER(Products,Products[Category]="Electronics"))

Multiple Expressions

Format these DAX measures:
1. [Total Sales] := SUM(Sales[Amount])
2. [Electronics Sales] := CALCULATE(SUM(Sales[Amount]),Products[Category]="Electronics")
3. [Sales YTD] := TOTALYTD(SUM(Sales[Amount]),'Calendar'[Date])

With Formatting Options

Format this DAX with short lines and specific separators:
CALCULATE(SUM(Sales[Amount]),FILTER(Products,Products[Category]="Electronics"))

Options:
- Line length: ShortLine
- List separator: ;
- Decimal separator: ,

🔧 Available Tools

format_dax

Formats a single DAX expression.

Parameters:

• dax (required): The DAX expression to format
• options (optional): Formatting options object

Example:

{
  "dax": "CALCULATE(SUM(Sales[Amount]),FILTER(Products,Products[Category]=\"Electronics\"))",
  "options": {
    "maxLineLength": "LongLine",
    "skipSpaceAfterFunctionName": "BestPractice"
  }
}

format_dax_multiple

Formats multiple DAX expressions in a single request.

Parameters:

• expressions (required): Array of DAX expressions to format
• options (optional): Formatting options object

Example:

{
  "expressions": [
    "CALCULATE(SUM(Sales[Amount]),FILTER(Products,Products[Category]=\"Electronics\"))",
    "[Total Sales] := SUM(Sales[Amount])"
  ],
  "options": {
    "maxLineLength": "LongLine",
    "databaseName": "SalesDB",
    "serverName": "ProductionServer"
  }
}

🎛️ Formatting Options

All formatting options are optional and have sensible defaults:

Option	Values	Default	Description
maxLineLength	ShortLine, LongLine, VeryLongLine	LongLine	Maximum line length for formatted code
skipSpaceAfterFunctionName	BestPractice, False	BestPractice	Spacing after function names
listSeparator	Any character	,	Character used as list separator
decimalSeparator	Any character	.	Character used as decimal separator
databaseName	String	-	Database name for context (anonymized)
serverName	String	-	Server name for context (anonymized)

📝 Example DAX Expressions

Here are some example DAX expressions you can test with:

Basic Measures

[Total Sales] := SUM(Sales[Amount])

Complex Calculations

CALCULATE(SUM(Sales[Amount]),FILTER(ALL(Products),Products[Category]="Electronics"),USERELATIONSHIP(Sales[OrderDate],'Calendar'[Date]))

Time Intelligence

[Sales YTD] := TOTALYTD(SUM(Sales[Amount]),'Calendar'[Date])

Table Expressions

EVALUATE FILTER(Customer, Customer[Country] = "USA")

🔍 Troubleshooting

Common Issues

Server fails to start:

• Ensure .NET 8.0 runtime is installed
• Check that the executable path is correct in your configuration
• Verify you have internet connectivity (required for DAX Formatter service)

Formatting requests fail:

• Check your internet connection
• Verify the DAX syntax is valid
• Try with simpler expressions first

MCP client doesn’t recognize the server:

• Restart your MCP client after adding the configuration
• Check the JSON configuration syntax
• Verify the executable path is absolute and correct

Debug Mode

To enable debug logging, you can run the server manually to see detailed logs:

# Run the server directly to see debug output
./dax-formatter-mcp.exe

Then send JSON-RPC messages manually to test functionality.

🏗️ Architecture

The MCP server is built with:

• .NET 9.0: Modern, cross-platform runtime
• DAX Formatter Client: Official NuGet package from SQLBI
• JSON-RPC 2.0: Standard protocol for MCP communication
• Async/Await: Non-blocking I/O for better performance

Flow Diagram

MCP Client → JSON-RPC → DAX Formatter MCP Server → DAX Formatter API → Formatted DAX

🤝 Contributing

Contributions are welcome! Please follow these steps:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Make your changes
4. Add tests if applicable
5. Commit your changes (git commit -m 'Add amazing feature')
6. Push to the branch (git push origin feature/amazing-feature)
7. Open a Pull Request

Development Setup

# Clone the repository
git clone https://github.com/EmanueleMeazzo/dax-formatter-mcp.git
cd dax-formatter-mcp

# Restore dependencies
dotnet restore

# Build the project
dotnet build

# Run tests
dotnet test

🔒 Privacy & Security

• All DAX expressions are sent to the official DAX Formatter service at daxformatter.com
• Database and server names are anonymized by the DAX Formatter client
• No DAX expressions are stored locally
• No personal information is collected or transmitted

📜 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• SQLBI for the excellent DAX Formatter service
• Anthropic for the Model Context Protocol specification
• Microsoft for the DAX language

📚 Related Resources

• DAX Formatter Website
• DAX Code Formatting Rules
• Model Context Protocol
• DAX Language Reference