Revit MCP Server

Control Autodesk Revit through natural language using Claude AI. This project implements a Model Context Protocol (MCP) server that bridges Claude Desktop and Revit 2023, enabling AI-driven BIM operations through 61 tools.

Ask Claude "list all walls", "create a sheet with building elevations", or "count doors by level" and it executes directly in your Revit model.

Architecture

Claude Desktop ──(stdio/MCP)──► TypeScript MCP Server ──(HTTP :8080)──► C# Revit Plugin ──► Revit API

Component	Language	Role
MCP Server	TypeScript / Node.js	Translates MCP tool calls from Claude Desktop into HTTP requests
Revit Plugin	C# / .NET Framework 4.8	Receives HTTP requests and executes Revit API operations on the main thread

The C# plugin uses the ExternalEvent pattern for thread-safe Revit API access. An HttpListener on localhost:8080 receives tool requests, queues them via ExternalEvent, and waits for the result.

Prerequisites

• Autodesk Revit 2023 (installed at default path C:\Program Files\Autodesk\Revit 2023\)
• Node.js v18+ (download)
• .NET Framework 4.8 Developer Pack (download)
• Claude Desktop (download)

Project Structure

revit-mcp-server/
├── RevitPlugin/                    # C# Revit Add-in
│   ├── App.cs                      # Plugin entry point (IExternalApplication)
│   ├── HttpServer.cs               # HTTP server on localhost:8080
│   ├── ExternalEventHandler.cs     # Thread-safe Revit API execution
│   ├── ToolRouter.cs               # Routes tool names to handlers
│   ├── RevitMcpPlugin.csproj       # .NET project file
│   ├── RevitMcpPlugin.addin        # Revit add-in manifest
│   ├── Tools/
│   │   ├── QueryTools.cs           # get_elements, find_elements, quantities
│   │   ├── ElementTools.cs         # create/delete/move/copy elements
│   │   ├── ParameterTools.cs       # get/set parameter values
│   │   ├── ViewTools.cs            # manage views, duplicate, filters
│   │   ├── SheetTools.cs           # create sheets, place viewports
│   │   ├── SelectionTools.cs       # select elements by criteria
│   │   ├── VisibilityTools.cs      # hide/isolate/unhide elements
│   │   ├── LevelGridTools.cs       # levels, grids, rename elements
│   │   ├── MEPTools.cs             # panel schedules, conduit QA, room contents
│   │   ├── AnnotationTools.cs      # tags, duplicate tag detection
│   │   └── ProjectTools.cs         # categories list, warnings
│   └── Helpers/
│       ├── CategoryHelper.cs       # Category name resolution (60+ aliases)
│       ├── UnitHelper.cs           # Unit conversions (mm/m/ft/in)
│       └── JsonHelper.cs           # Element-to-JSON serialization
│
├── mcp-server/                     # TypeScript MCP Server
│   ├── package.json
│   ├── tsconfig.json
│   ├── .env.example
│   └── src/
│       ├── index.ts                # Entry point
│       ├── server.ts               # MCP server setup + tool registration
│       ├── revit-client.ts         # HTTP client for Revit plugin
│       ├── types.ts                # TypeScript interfaces
│       └── tools/
│           ├── query-tools.ts      # Element query tools
│           ├── element-tools.ts    # Element creation/modification tools
│           ├── parameter-tools.ts  # Parameter tools
│           ├── view-tools.ts       # View management tools
│           ├── sheet-tools.ts      # Sheet management tools
│           ├── selection-tools.ts  # Selection tools
│           ├── visibility-tools.ts # Visibility tools
│           ├── level-grid-tools.ts # Level/grid tools
│           ├── mep-tools.ts        # MEP tools
│           ├── annotation-tools.ts # Annotation tools
│           └── project-tools.ts    # Project-wide tools
│
└── README.md

Setup Instructions

Step 1: Build the C# Revit Plugin

1. Open a terminal and navigate to the RevitPlugin folder:

cd RevitPlugin

2. Restore NuGet packages and build:

dotnet restore
dotnet build -c Release

Note: The .csproj references Revit API DLLs from C:\Program Files\Autodesk\Revit 2023\. If your Revit is installed elsewhere, update the <HintPath> entries in RevitMcpPlugin.csproj.

3. The build output will be in RevitPlugin\bin\Release\:
   • RevitMcpPlugin.dll
   • Newtonsoft.Json.dll

Step 2: Deploy the Revit Plugin

Copy three files to the Revit 2023 add-ins folder:

# Create target folder variable
set ADDIN_DIR=%APPDATA%\Autodesk\Revit\Addins\2023

# Copy the add-in manifest
copy RevitPlugin\RevitMcpPlugin.addin "%ADDIN_DIR%\"

# Copy the built DLLs
copy RevitPlugin\bin\Release\RevitMcpPlugin.dll "%ADDIN_DIR%\"
copy RevitPlugin\bin\Release\Newtonsoft.Json.dll "%ADDIN_DIR%\"

After copying, the folder should contain:

%APPDATA%\Autodesk\Revit\Addins\2023\
├── RevitMcpPlugin.addin
├── RevitMcpPlugin.dll
└── Newtonsoft.Json.dll

Step 3: Install MCP Server Dependencies

cd mcp-server
npm install

Step 4: Build the MCP Server

cd mcp-server
npx tsc

This compiles TypeScript to JavaScript in the mcp-server/dist/ folder.

Step 5: Configure Claude Desktop

Open the Claude Desktop configuration file:

%APPDATA%\Claude\claude_desktop_config.json

Add the revit entry under mcpServers:

{
  "mcpServers": {
    "revit": {
      "command": "node",
      "args": [
        "C:\\FULL\\PATH\\TO\\github_revit_MCP_server\\mcp-server\\dist\\index.js"
      ],
      "env": {
        "REVIT_HOST": "localhost",
        "REVIT_PORT": "8080"
      }
    }
  }
}

Important: Replace C:\\FULL\\PATH\\TO\\ with the actual absolute path to your project folder. Use double backslashes \\ in JSON.

Step 6: Launch

1. Start Revit 2023 and open a project. The plugin will automatically load and start the HTTP server on port 8080. You should see a confirmation dialog.

2. Restart Claude Desktop so it picks up the new MCP server configuration.

3. Start chatting! Open a new conversation in Claude Desktop and try:

   • "List all walls in the model"
   • "Get project information"
   • "Count all doors grouped by type"
   • "Create a new sheet A-501 called Building Elevations"

Verify the Connection

You can verify each component independently:

Check the Revit Plugin HTTP server:

curl http://localhost:8080/health

Expected response:

{
  "success": true,
  "status": "running",
  "revitConnected": true,
  "documentName": "YourProject.rvt",
  "serverVersion": "1.0.0"
}

Test a tool call directly:

curl -X POST http://localhost:8080/execute -H "Content-Type: application/json" -d "{\"tool\": \"get_project_info\", \"parameters\": {}}"

Available Tools (61)

Query Tools (10)

Tool	Description
get_elements	Get elements by category with pagination
get_element_parameters	Get all parameters for an element
find_elements_by_parameter	Find elements matching a parameter value
calculate_quantities	Calculate area, length, volume takeoffs
count_elements_by_category	Count elements in one or all categories
count_elements_by_family	Count elements grouped by family and type
get_element_by_id	Get detailed info for a single element
get_element_room	Find which room contains an element
get_project_info	Get project metadata
export_schedule_data	Export Revit schedule as JSON

Element Tools (8)

Tool	Description
create_wall	Create a wall between two points
create_floor	Create a floor from boundary points
create_room	Create a room at a point on a level
create_family_instance	Place a family instance (door, window, furniture)
delete_elements	Delete elements by IDs
move_element	Move an element by a translation vector
rotate_element	Rotate an element by degrees
copy_element	Copy an element to a new location

Parameter Tools (4)

Tool	Description
get_parameter_value	Get a specific parameter value
set_parameter_value	Set a parameter value
get_parameter_names	List all parameters on an element
batch_set_parameters	Set same parameter on multiple elements

View Tools (6)

Tool	Description
get_views	List all views, filter by type
get_active_view	Get the currently active view
activate_view	Switch to a different view
duplicate_view	Duplicate a view
create_dependent_view	Create a dependent view
get_view_filters	List filters applied to a view

Sheet Tools (6)

Tool	Description
get_sheets	List all sheets with viewports
create_sheet	Create a new sheet
place_view_on_sheet	Place a view on a sheet
get_sheet_viewports	List viewports on a sheet
rename_sheet	Rename a sheet
duplicate_and_place_view	Duplicate a view and place it on a sheet in one step

Selection Tools (8)

Tool	Description
get_current_selection	Get currently selected elements
select_elements_by_ids	Select elements by their IDs
select_all_by_category	Select all elements of a category
select_elements_by_level	Select elements on a specific level
select_by_parameter_value	Select elements matching a parameter
select_and_hide_category	Select and hide a category
select_and_isolate_category	Isolate a category
clear_selection	Clear the current selection

Visibility Tools (6)

Tool	Description
hide_elements_by_category	Hide all elements of a category
unhide_elements_by_category	Unhide a hidden category
isolate_elements_by_category	Temporarily isolate a category
isolate_elements_by_selection	Isolate the current selection
unhide_all	Reset all hide/isolate in active view
unisolate_all	Reset temporary isolation

Level & Grid Tools (4)

Tool	Description
get_levels	List all levels with elevations
get_grids	List all grids
create_level	Create a new level
rename_elements	Batch rename elements

MEP Tools (5)

Tool	Description
get_panel_schedules	Get electrical panel schedules
calculate_conduit_bends	Analyze conduit bend calculations
conduit_qa_check	QA check on conduit systems
analyze_wall_lengths_by_level	Wall lengths/areas grouped by level
get_elements_in_room	Find elements within a room

Annotation Tools (4)

Tool	Description
create_tag	Tag an element in the active view
tag_all_in_view	Auto-tag all untagged elements of a category
find_duplicate_tags	Find elements with multiple tags
get_element_orientation	Get facing direction of an element

Project Tools (2)

Tool	Description
get_all_categories	List all categories with element counts
get_warnings	Get all Revit warnings/errors

Adapting for Other Revit Versions

This project targets Revit 2023 (.NET Framework 4.8). To adapt for other versions:

Revit 2024+ (.NET Framework 4.8)

• Update <HintPath> in .csproj to point to Revit 2024 installation
• Deploy to %APPDATA%\Autodesk\Revit\Addins\2024\
• API should be mostly compatible

Revit 2025+ (.NET 8)

• Change <TargetFramework> in .csproj from net48 to net8.0-windows
• Update <HintPath> to Revit 2025 installation path
• Replace deprecated API calls (some SpecTypeId patterns may differ)
• Deploy to %APPDATA%\Autodesk\Revit\Addins\2025\

Troubleshooting

"Server disconnected" in Claude Desktop

1. Check the MCP log: Open %APPDATA%\Claude\logs\mcp-server-revit.log
2. Common fix: Make sure you built the TypeScript with npx tsc and the path in claude_desktop_config.json points to the dist/index.js file (not src/index.ts)
3. Path issue: The args array must contain the absolute path to dist/index.js with double backslashes

Revit plugin not loading

1. Verify all 3 files are in %APPDATA%\Autodesk\Revit\Addins\2023\:
   • RevitMcpPlugin.addin
   • RevitMcpPlugin.dll
   • Newtonsoft.Json.dll
2. Check that the .addin file is not blocked: right-click > Properties > Unblock
3. Restart Revit after deployment

"Tool execution timed out"

• Revit may be busy with another operation. Wait and retry.
• Large models may need more than the 30-second timeout

Health check returns revitConnected: false

• Make sure a Revit project document is open (not just the start screen)

How It Works

1. Claude Desktop sends an MCP tools/call request (e.g., get_elements with {category: "Walls"}) via stdio
2. The TypeScript MCP Server receives it, translates it to an HTTP POST to localhost:8080/execute
3. The C# Revit Plugin HttpServer receives the request, sets the tool + parameters on the ExternalEventHandler, and raises the ExternalEvent
4. Revit picks up the ExternalEvent on its main thread and executes the Revit API call
5. The result flows back: Revit API response -> JSON -> HTTP response -> MCP response -> Claude Desktop

The ExternalEvent + ManualResetEventSlim pattern ensures all Revit API calls happen on the main thread (required by Revit), while the HTTP server can handle requests from a background thread.

Rebuilding After Changes

If you modify any source files:

C# Plugin changes:

cd RevitPlugin
dotnet build -c Release
# Re-copy DLLs to Revit addins folder
copy bin\Release\RevitMcpPlugin.dll "%APPDATA%\Autodesk\Revit\Addins\2023\"
# Restart Revit

TypeScript MCP Server changes:

cd mcp-server
npx tsc
# Restart Claude Desktop

License

MIT License - see LICENSE for details.

Acknowledgments

• Model Context Protocol by Anthropic
• Revit API Documentation
• Inspired by archsalem101/revit-mcp-server