DLL Inspector MCP Server

Version 2.1.0 - Improved parameter default value handling

A Model Context Protocol (MCP) server that analyzes .NET assembly DLLs and stores metadata in a SQLite database for efficient querying. Originally designed for exploring Autodesk Civil 3D and AutoCAD APIs, now supports multiple software products in a single database.

Overview

This MCP server provides a comprehensive database-driven solution for exploring .NET APIs. Instead of loading DLLs every time you query them, it analyzes assemblies once and stores all metadata (types, methods, properties, parameters, etc.) in a SQLite database for fast, powerful queries.

Key Features

• Software Differentiation (NEW in v2.0): Organize DLLs by software product (Civil 3D, Revit, Dynamo, etc.)
• Filtered Queries (NEW in v2.0): Query only DLLs from specific software without searching the entire database
• Automatic Migration: Seamlessly upgrades from v1 to v2 schema
• One-time analysis: Analyze DLLs once and query the database repeatedly without reloading
• Comprehensive metadata: Captures types, methods, properties, fields, events, parameters, inheritance, interfaces, and more
• Smart updates: Hash-based change detection only re-analyzes when DLLs change
• Powerful queries: Search by name, namespace, return type, inheritance, interface implementations
• Full-text search: Find members by documentation and descriptions
• Cross-platform: Automatically handles Windows path to WSL path conversion

MCP Tools

Database Management

analyze_dll

Analyzes a .NET DLL and stores all metadata in the database.

Parameters:

• dllPath (required): Path to the DLL file (Windows or WSL format)
• forceReAnalyze (optional): Force re-analysis even if already in database (default: false)
• softwareName (optional, NEW in v2.0): Software name to associate with this DLL (e.g., "AutoCAD Civil 3D 2024")
• softwareVersion (optional, NEW in v2.0): Software version

Example:

dllPath: "C:\Program Files\Autodesk\AutoCAD 2024\C3D\AeccDbMgd.dll"
softwareName: "AutoCAD Civil 3D"
softwareVersion: "2024"

list_assemblies

Lists all assemblies currently in the database with statistics.

Parameters:

• softwareName (optional, NEW in v2.0): Filter assemblies by software name

Returns: Assembly names, versions, software association, analysis dates, namespace counts, and type counts

list_software (NEW in v2.0)

Lists all software products in the database with assembly counts.

Returns: Software names, versions, descriptions, and number of associated assemblies

associate_assembly_with_software (NEW in v2.0)

Associates an existing assembly with a software product.

Parameters:

• assemblyName (required): Assembly name
• softwareName (required): Software name

Example:

assemblyName: "AeccDbMgd"
softwareName: "AutoCAD Civil 3D"

Type Discovery

list_namespaces

Lists all namespaces in the database.

Parameters:

• assemblyName (optional): Filter by specific assembly name

Example:

assemblyName: "AeccDbMgd"

search_types

Searches for types by name pattern. Supports SQL wildcards (%).

Parameters:

• searchPattern (required): Search pattern (e.g., "Alignment", "%Pipe%", "Surface%")
• namespaceName (optional): Filter by namespace
• typeKind (optional): Filter by type kind (Class, Interface, Enum, Struct)

Examples:

searchPattern: "%Alignment%"
namespaceName: "Autodesk.Civil.DatabaseServices"

searchPattern: "Pressure%"
typeKind: "Class"

get_type_details

Gets comprehensive information about a specific type including all members.

Parameters:

• typeName (required): Full type name

Example:

typeName: "Autodesk.Civil.DatabaseServices.Alignment"

Returns: Type information, base class, interfaces, constructors, properties, methods, fields, events with full signatures

Method Discovery

search_methods

Searches for methods by name pattern across all types.

Parameters:

• searchPattern (required): Method name pattern (e.g., "%Station%", "Get%")
• returnType (optional): Filter by return type

Examples:

searchPattern: "%Station%"

searchPattern: "Get%"
returnType: "%Surface%"

Advanced Queries

search_documentation

Full-text search across all type and member documentation.

Parameters:

• searchTerms (required): Search terms to find in documentation

Example:

searchTerms: "corridor surface"

get_inheritance_tree

Shows the inheritance hierarchy for a type (base classes and derived classes).

Parameters:

• typeName (required): Full type name

Example:

typeName: "Autodesk.Civil.DatabaseServices.Alignment"

find_implementations

Finds all types that implement a specific interface.

Parameters:

• interfaceName (required): Full interface name

Example:

interfaceName: "System.IDisposable"

Installation

Prerequisites

• .NET 9.0 SDK
• WSL2 (if running on Windows)

Build

cd /mnt/c/Users/jjhaddad/Documents/Work/zeroTouch/dll-inspector-mcp
dotnet build

The built executable will be located at:

bin/Debug/net9.0/DllInspectorMcp.dll

Configuration for Claude Code

Add this server to your Claude Code MCP settings file.

Location of settings file:

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

Configuration example:

{
  "mcpServers": {
    "civil3d-inspector": {
      "command": "dotnet",
      "args": [
        "exec",
        "/mnt/c/Users/jjhaddad/Documents/Work/zeroTouch/dll-inspector-mcp/bin/Debug/net9.0/DllInspectorMcp.dll"
      ]
    }
  }
}

Note: Adjust the path to match your installation location.

Usage Workflow

1. Analyze DLLs (with Software Association)

First, analyze the assemblies you want to explore. New in v2.0: You can now associate DLLs with software products:

analyze_dll
  dllPath: "C:\Program Files\Autodesk\AutoCAD 2024\C3D\AeccDbMgd.dll"
  softwareName: "AutoCAD Civil 3D"
  softwareVersion: "2024"

You can analyze multiple software products in the same database:

analyze_dll
  dllPath: "C:\Program Files\Autodesk\Revit 2024\RevitAPI.dll"
  softwareName: "Revit"
  softwareVersion: "2024"

analyze_dll
  dllPath: "C:\Program Files\Dynamo\DynamoCore.dll"
  softwareName: "Dynamo"
  softwareVersion: "2.x"

The first analysis will take time, but subsequent queries will be instant!

Tip: Software association is optional. If you don't specify it, the DLL will still be analyzed and available for querying.

2. Explore the API

New in v2.0: View all software products and filter by software:

list_software

List assemblies from a specific software:

list_assemblies
  softwareName: "AutoCAD Civil 3D"

List available namespaces:

list_namespaces
  assemblyName: "AeccDbMgd"

Find types related to alignments:

search_types
  searchPattern: "%Alignment%"
  namespaceName: "Autodesk.Civil.DatabaseServices"

Get full details on a specific type:

get_type_details
  typeName: "Autodesk.Civil.DatabaseServices.Alignment"

Search for methods:

search_methods
  searchPattern: "%Station%"

Find inheritance relationships:

get_inheritance_tree
  typeName: "Autodesk.Civil.DatabaseServices.Corridor"

3. Updates

If you update Civil3D or the DLLs change, simply re-analyze:

analyze_dll
  dllPath: "C:\Program Files\Autodesk\AutoCAD 2024\C3D\AeccDbMgd.dll"
  forceReAnalyze: true

Database Location

The SQLite database is created at:

bin/Debug/net9.0/civil3d_api.db

You can inspect or query it directly using any SQLite client.

Database Schema

The database includes the following tables:

• Software (NEW in v2.0): Software product information
• Assemblies: DLL metadata and versions (now with optional SoftwareId)
• Namespaces: Namespace organization
• Types: Classes, interfaces, enums, structs
• Members: Methods, properties, fields, events, constructors
• Parameters: Method and constructor parameters
• TypeInterfaces: Interface implementations
• EnumValues: Enumeration values
• PropertyAccessors: Property getter/setter information
• MembersSearch: Full-text search index

See DatabaseSchema.sql for the complete v1 schema, or DatabaseSchema_v2.sql for v2 schema. See MIGRATION_V2.md for migration details.

Architecture

Components

• DatabaseManager.cs: SQLite database operations and management
• DllAnalyzer.cs: Extracts metadata from .NET assemblies using MetadataLoadContext
• DatabaseQueryTools.cs: MCP tools for querying the database
• DllLoader.cs: Assembly loading with dependency resolution and path conversion
• DatabaseSchema.sql: Complete database schema with indexes and views

Key Technologies

• SQLite: Lightweight, file-based database
• MetadataLoadContext: Reflection-only assembly loading
• FTS5: SQLite full-text search for documentation
• Model Context Protocol: Integration with Claude Code

Path Handling

The server automatically converts Windows paths to WSL paths when running in WSL:

• C:\path\to\file.dll → /mnt/c/path/to/file.dll
• Works with all drive letters (C:, D:, etc.)

You can use either format when calling the tools.

Performance

• First analysis: May take 30-60 seconds for large DLLs like AeccDbMgd.dll
• Subsequent queries: Milliseconds (database lookups)
• Re-analysis: Only when DLL file hash changes
• Database size: ~10-50 MB per analyzed assembly

Troubleshooting

Error: "Path is not an absolute path"

• Ensure the DLL path is correct
• Try using the full WSL path format: /mnt/c/...

Error: "Could not load file or assembly"

• The DLL may have dependencies in the same directory
• The server attempts to load dependencies automatically from the DLL's directory

Database not found or empty

• The database is created automatically on first use
• Use analyze_dll to populate it with your DLLs

Slow queries

• The first query after starting the server may initialize the database
• Subsequent queries should be very fast
• Consider re-analyzing if you suspect data corruption

Documentation

• CHANGELOG.md: Version history and changes
• FEATURE_SUMMARY.md: Summary of v2.0 software differentiation feature
• MIGRATION_V2.md: Database migration guide from v1 to v2
• CIVIL3D_API_STRUCTURE.md: Comprehensive documentation of the Civil3D API structure
• PROJECT_STATUS.md: Project development status and roadmap
• DatabaseSchema.sql: Complete v1 database schema with comments
• DatabaseSchema_v2.sql: Complete v2 database schema with Software table

Dependencies

• .NET 9.0
• Microsoft.Data.Sqlite (9.0.0)
• Microsoft.Extensions.Hosting (10.0.0)
• ModelContextProtocol (0.4.0-preview.3)
• System.Reflection.MetadataLoadContext (9.0.0)

Development

Build

dotnet build

Run

dotnet run

Clean Database

To start fresh, delete the database file:

rm bin/Debug/net9.0/civil3d_api.db

References

• Model Context Protocol Documentation
• Build a Model Context Protocol (MCP) server in C#
• MCP C# SDK GitHub
• Civil 3D .NET API Reference
• Autodesk Developer Documentation

License

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

Copyright (c) 2025 Jad Haddad