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# 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](https://www.daxformatter.com/) service by SQLBI to deliver professional-grade DAX code formatting.
[](https://dotnet.microsoft.com/download/dotnet/8.0)
[](LICENSE)
[](https://modelcontextprotocol.io/)
## 🚀 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](https://dotnet.microsoft.com/download/dotnet/8.0) 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](https://github.com/EmanueleMeazzo/dax-formatter-mcp/releases) page
2. Extract the archive to your preferred location
3. Note the path to the executable for configuration
### Option 2: Build from Source
```bash
# 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`
```json
{
"mcpServers": {
"dax-formatter": {
"command": "path/to/dax-formatter-mcp.exe",
"args": []
}
}
}
```
### Continue IDE Extension
Add to your Continue configuration:
```json
{
"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:
```json
{
"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:
```json
{
"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:**
```json
{
"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:**
```json
{
"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
```dax
[Total Sales] := SUM(Sales[Amount])
```
### Complex Calculations
```dax
CALCULATE(SUM(Sales[Amount]),FILTER(ALL(Products),Products[Category]="Electronics"),USERELATIONSHIP(Sales[OrderDate],'Calendar'[Date]))
```
### Time Intelligence
```dax
[Sales YTD] := TOTALYTD(SUM(Sales[Amount]),'Calendar'[Date])
```
### Table Expressions
```dax
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:
```bash
# 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
```bash
# 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](LICENSE) file for details.
## 🙏 Acknowledgments
- [SQLBI](https://www.sqlbi.com/) for the excellent DAX Formatter service
- [Anthropic](https://www.anthropic.com/) for the Model Context Protocol specification
- [Microsoft](https://docs.microsoft.com/en-us/dax/) for the DAX language
## 📚 Related Resources
- [DAX Formatter Website](https://www.daxformatter.com/)
- [DAX Code Formatting Rules](https://www.sqlbi.com/articles/rules-for-dax-code-formatting/)
- [Model Context Protocol](https://modelcontextprotocol.io/)
- [DAX Language Reference](https://docs.microsoft.com/en-us/dax/)
