MCP X++ Server

A Model Context Protocol (MCP) server for Microsoft Dynamics 365 Finance & Operations development. This tool enables D365 object creation, modification, and analysis through the MCP standard, allowing integration with various development environments.

Date: September 18, 2025
Status: Functional with VS2022 service integration and enhanced form creation

Recent Updates ✨

September 19, 2025 - Safe Object Deletion Feature:

• 🗑️ NEW delete_xpp_object Tool: Safe D365 object deletion with dependency validation and cascade support

• 🛡️ Dependency Protection: Prevents deletion if other objects depend on target, avoiding breaking changes

• 🔄 Cache Consistency: Automatic search index updates after successful deletions

• ⚡ High Performance: Direct metadata provider integration with ISingleKeyedMetadataProvider.Delete

• 🌲 Cascade Deletion: Optional deletion of child objects (form parts, table relations, etc.)

• ✅ Comprehensive Testing: Full create/delete cycle validation across object types

September 18, 2025 - Array Modifications & Form Creation Enhancements:

• 🚀 NEW Array-Only Modifications: execute_object_modification now exclusively uses batch format for consistent operations

• 🔄 Enforced Bulk Processing: Single operations use array with one element - no more consecutive separate calls

• 📊 Enhanced Response Tracking: Per-operation success/failure reporting with detailed timing and error messages

• 📋 Best Practice Documentation: Clear guidance to group all modifications for same object into single call

• 🎯 NEW create_form Tool: Specialized form creation with pattern support and datasource integration

• 🔧 DetailsMaster Pattern Fixed: Resolved validation issues through intelligent field control creation

• 🗄️ Enhanced DataSource Support: Flexible datasource handling (arrays, strings, comma-separated)

• 📋 Pattern Discovery: 36 filtered form patterns with descriptions and requirements

• ✅ Pattern Validation: Automatic field control creation for patterns requiring them

Overview

This MCP server provides D365 F&O development capabilities including:

• Object Creation: Support for D365 classes, tables, forms, enums, and 544+ other object types

• Form Creation: ✨ Enhanced - Specialized form creation with pattern validation and datasource integration

• Object Deletion: ✨ NEW - Safe object deletion with dependency validation and cascade support

• Object Modification: Add methods, fields, and other components to existing objects

• Object Inspection: Analyze D365 objects and extract X++ source code

• Codebase Search: Browse and search through D365 codebases with pattern matching

• MCP Protocol: Compatible with Claude Desktop, VS Code, and other MCP clients

Architecture

The system consists of two main components communicating through Windows Named Pipes:

MCP X++ Server (Node.js/TypeScript)

• Implements the Model Context Protocol (STDIO)

• Handles object creation, modification, and search operations

• Provides file browsing and codebase indexing

• Compatible with MCP clients like Claude Desktop and VS Code

D365 Metadata Service (C# .NET 4.8)

• Integrates with Microsoft's D365 assemblies

• Handles object creation and modification through VS2022 APIs

• Provides dynamic reflection for runtime object discovery

• Communicates via Named Pipe: mcp-xpp-d365-service

The architecture enables D365 development from various MCP-compatible clients while maintaining compatibility with existing D365 development workflows.

Available Tools

The server provides 10 specialized tools for D365 development:

1. create_xpp_object - Create D365 objects (classes, tables, enums, etc.) - Note: Use create_form for forms

2. create_form - ✨ NEW - Specialized form creation with pattern support and datasource integration

3. delete_xpp_object - ✨ NEW - Safe D365 object deletion with dependency validation and cache consistency

4. execute_object_modification - ✨ ENHANCED - Array-based object modification with batch processing - BEST PRACTICE: Group all modifications for same object

5. discover_modification_capabilities - Explore available modification methods

6. find_xpp_object - Find specific objects by name/type

7. search_objects_pattern - Pattern search with wildcard support

8. inspect_xpp_object - Object analysis with X++ source code extraction

9. get_current_config - System configuration and status

10. build_object_index - Index management for search performance

Prerequisites

• Visual Studio 2022 (Community, Professional, or Enterprise)

• Dynamics 365 Development Tools for Visual Studio 2022

• Node.js (latest LTS version recommended)

• .NET Framework 4.8 (typically included with Windows)

Installation

1. Clone the repository

2. Install Node.js dependencies: npm install

3. Run setup to configure VS2022 integration: .\tools\build-and-run.ps1 -Action setup

4. Build the project: .\tools\build-and-run.ps1 -Action build

Usage

Starting the Server

Run the MCP server using:

The server automatically detects D365 paths from your VS2022 installation. For manual configuration, use:

MCP Client Configuration

VS Code

Configure in .vscode/mcp.json:

Claude Desktop

Add to Claude Desktop configuration file:

Tool Reference

Object Creation

create_xpp_object

Creates D365 F&O objects using VS2022 service integration.

⚠️ Important: For creating forms, use the dedicated create_form tool instead as it provides specialized pattern support and datasource integration.

Parameters:

• objectName (string) - Name of the D365 object

• objectType (string) - Object type (AxClass, AxTable, AxEnum, etc.) - Excludes AxForm

• layer (string, optional) - Application layer (usr, cus, var)

• outputPath (string, optional) - Output directory (default: "Models")

• publisher (string, optional) - Company name (default: "YourCompany")

• version (string, optional) - Version number (default: "1.0.0.0")

• dependencies (array, optional) - Model dependencies

• properties (object, optional) - Object-specific configuration

Example:

create_form ✨ NEW

Specialized tool for creating D365 forms with advanced pattern support and datasource integration. This tool combines form creation and pattern discovery in one interface.

Parameters:

• mode (string, required) - Operation mode:

  • "create" - Create a new form with patterns and datasources

  • "list_patterns" - Discover available D365 form patterns

• formName (string, optional) - Form name (required when mode='create')

• patternName (string, optional) - D365 form pattern to apply (e.g., 'SimpleListDetails', 'DetailsMaster', 'Dialog')

• patternVersion (string, optional) - Pattern version (default: 'UX7 1.0')

• dataSources (array|string, optional) - Table names for form datasources

• modelName (string, optional) - D365 model/package name (default: 'ApplicationSuite')

Key Features:

• 🎯 Pattern-Aware: Automatically adds field controls when patterns require them (e.g., DetailsMaster)

• 🗄️ Flexible DataSources: Supports arrays, single strings, or comma-separated strings

• 🔍 Pattern Discovery: Lists all 36+ available D365 form patterns with descriptions

• ✅ Enhanced Validation: Resolves pattern validation issues through intelligent field control creation

Examples:

Technical Notes:

• Patterns like DetailsMaster, SimpleListDetails, and ListPage automatically get enhanced with field controls (RecId, Name, Description, Code) when datasources are provided

• Pattern validation has been fixed - forms can be created with or without datasources depending on pattern requirements

• The tool uses direct VS2022 service integration for optimal D365 compatibility

delete_xpp_object ✨ NEW

Safely deletes D365 F&O objects with comprehensive dependency validation and cache consistency. This tool prevents breaking changes by validating dependencies before deletion.

Parameters:

• objectName (string, required) - Name of the D365 object to delete

• objectType (string, required) - D365 object type (AxClass, AxTable, AxForm, AxEnum, etc.)

• cascadeDelete (boolean, optional) - Delete dependent objects too (default: false)

Key Features:

• 🛡️ Dependency Validation: Prevents deletion if other objects depend on the target

• 🗑️ Safe Deletion: Uses D365's ISingleKeyedMetadataProvider.Delete for proper cleanup

• 🔄 Cache Consistency: Automatically updates search index after successful deletion

• ⚡ Fast Performance: Direct metadata provider integration for optimal speed

• 🌲 Cascade Support: Optional deletion of child objects (forms with parts/controls, etc.)

Examples:

Response Format:

⚠️ Safety Notes:

• HIGH RISK OPERATION: Deletion is permanent and cannot be undone

• Always verify dependencies with find_xpp_object before deletion

• Use cascadeDelete: false (default) for maximum safety

• Test deletions in development environments first

• Tool will fail safely if dependencies exist without cascade flag

• Cache updates ensure immediate search consistency after deletion

Common Object Types:

• AxClass - X++ classes and business logic

• AxTable - Data tables and schema

• AxForm - User interface forms

• AxEnum - Enumerations and value lists

• AxEdt - Extended data types

• AxView - Database views

• AxQuery - Data queries

• AxReport - SSRS reports

Object Discovery

find_xpp_object

Locates X++ objects by name with optional filtering.

Parameters:

• objectName (string, required) - Name of the X++ object

• objectType (string, optional) - Filter by object type

• model (string, optional) - Filter by D365 model/package name

search_objects_pattern

Searches D365 objects using wildcard patterns.

Parameters:

• pattern (string, required) - Search pattern with wildcards (*, ?)

• objectType (string, optional) - Filter by object type

• model (string, optional) - Filter by D365 model/package name

• limit (number, optional) - Maximum results (default: 50)

• format (string, optional) - Output format: 'text' or 'json'

inspect_xpp_object

Analyzes D365 objects with multiple inspection modes.

Parameters:

• objectName (string, required) - Name of the X++ object

• objectType (string, optional) - D365 object type

• inspectionMode (string, optional) - Inspection level:

  • summary - Fast overview with collection counts

  • properties - All object properties with descriptions

  • collection - Specific collection items (requires collectionName)

  • xppcode - Extract X++ source code (requires codeTarget)

• collectionName (string, optional) - Required when inspectionMode='collection'

• codeTarget (string, optional) - Required when inspectionMode='xppcode':

  • methods - Extract all method source code

  • specific-method - Single method (requires methodName)

  • event-handlers - Event handler methods only

• methodName (string, optional) - Required when codeTarget='specific-method'

• maxCodeLines (number, optional) - Limit lines of source code per method

• filterPattern (string, optional) - Wildcard filter for results

Examples:

Object Modification

execute_object_modification ✨ ENHANCED WITH BATCH PROCESSING

Executes modification methods on existing D365 objects with array-based batch processing. Always use array format - single operations use array with one element.

📋 BEST PRACTICE: Group ALL modifications for the same object into ONE call instead of making separate calls. This provides better performance, error handling, and transactional integrity.

Parameters:

• objectType (string, required) - D365 object type (e.g., 'AxTable', 'AxClass', 'AxForm')

• objectName (string, required) - Name of existing object to modify

• modifications (array, required) - Array of modification operations:

  • methodName (string, required) - Modification method to execute

  • parameters (object, required) - Method-specific parameters including:

    • concreteType (string, required) - Exact type from discover_modification_capabilities

    • Name (string) - Field/object name (use 'Name' not 'fieldName')

    • Other D365-specific parameters as required

✅ Features:

• Per-operation tracking: Each operation returns individual success/failure status

• Detailed error reporting: Clear validation messages for failed operations

• Sequential processing: Operations execute in order with timing information

• Batch efficiency: Multiple operations in single service call

Examples:

✅ Single field (array with one element):

⭐ Multiple fields in one batch (PREFERRED):

📊 Response Format: The tool returns detailed per-operation results:

💡 Tips:

• Use discover_modification_capabilities first to get exact parameter requirements

• All D365 table fields require parameters like SaveContents, Mandatory, etc.

• Group related modifications together for better performance

• Check individual operation results for debugging failed operations

discover_modification_capabilities

Discovers available modification methods for D365 object types.

Parameters:

• objectType (string, required) - D365 object type to analyze

System Management

get_current_config

Returns comprehensive server configuration and status information.

build_object_index

Builds or updates the searchable object index.

Parameters:

• objectType (string, optional) - Specific object type to index

• forceRebuild (boolean, optional) - Force complete rebuild

Supported Object Types

Common D365 object types supported:

• AxClass - X++ classes

• AxTable - Data tables

• AxForm - User interface forms

• AxEnum - Enumerations

• AxEdt - Extended data types

• AxView - Database views

• AxQuery - Data queries

• AxReport - SSRS reports

• AxMenuItemDisplay - Menu items

• AxDataEntityView - OData entities

The system supports 544+ object types total.

Build Scripts

The build-and-run.ps1 script provides unified project management:

Example Workflows

Creating a New Class

Searching and Analyzing Objects

Technical Details

Performance Characteristics

• Object indexing: Processes 70K+ objects in ~30 seconds

• Query response time: <50ms for most operations

• Search operations: Sub-second response for large codebases

• Memory usage: Optimized SQLite-based caching

File Type Support

• .xpp - X++ source files

• .xml - Metadata and configuration files

• .json - Configuration files

• Other D365 development files

Security

• Path validation prevents directory traversal

• Operations restricted to configured D365 codebase

• File size limits for resource management

• Input validation on all parameters

Troubleshooting

Common Issues

"VS2022 extension not found"

• Ensure Dynamics 365 Development Tools are installed in VS2022

• Run the setup script: .\tools\build-and-run.ps1 -Action setup

"Named pipe connection failed"

• Check that the C# service is running

• Verify Windows firewall settings

• Ensure .NET Framework 4.8 is installed

"Object not found" errors

• Build the object index: build_object_index

• Verify D365 codebase path configuration

• Check that the object exists in the specified model

"Pattern validation failed" for forms

• ✅ RESOLVED: This issue has been fixed in the latest version

• Forms with patterns like DetailsMaster now automatically include required field controls

• Use the create_form tool instead of create_xpp_object for better form creation

"Form creation without datasources fails"

• Most patterns work fine without datasources (e.g., DetailsMaster, Dialog patterns)

• Use create_form with "mode": "list_patterns" to see pattern requirements

• DataSources are optional for most patterns but enhance functionality when provided

Getting Help

• Check the logs/ folder for detailed error information

• Use get_current_config to verify system configuration

• Report issues on the GitHub repository

Contributing

This project welcomes contributions. Please:

1. Fork the repository

2. Create a feature branch

3. Make your changes with appropriate tests

4. Submit a pull request

Note that APIs may change as the project evolves.

License

MIT License - see LICENSE file for details.

Disclaimer

This software is provided "as is" without warranty. It is intended for research and development purposes only, not for production use.

Important Notes:

• Requires Visual Studio 2022 and D365 development tools

• Integration with Microsoft APIs is not officially supported

• Features may change or break between versions

• Use at your own risk in development environments only

Report issues or contribute improvements through the GitHub repository.