Revit MCP Server

A Model Context Protocol (MCP) server that connects Autodesk Revit 2025+ to AI assistants like Claude. Query elements, create views, manage sheets, and modify parameters — all through natural language.

How It Works

The system has two halves that communicate over a named pipe:

Claude Desktop / VS Code
        │
        │ stdio (JSON-RPC)
        ▼
┌─────────────────┐          Named Pipe           ┌──────────────────┐
│  RevitMcp.Server │  ◄──── "revit-mcp-bridge" ──► │  RevitMcp.Addin  │
│  (Console App)   │     length-prefixed JSON      │  (Revit Add-in)  │
└─────────────────┘                                └──────────────────┘
                                                           │
                                                    Revit API calls
                                                    (main thread only)

RevitMcp.Server is a standalone console app that speaks MCP over stdio. Claude Desktop launches it automatically.

RevitMcp.Addin loads inside Revit, runs a named-pipe listener on a background thread, and marshals all Revit API calls to the main thread via ExternalEvent.

RevitMcp.Core contains the shared contracts, command names, and handler implementations used by both sides.

Available Tools

Elements

Tool	Description
get_elements	Retrieve elements, optionally filtered by category (default limit: 100)
get_element_by_id	Get detailed info for a single element including bounding box and location
get_element_parameters	List all parameters and values for an element
get_selected_elements	Get currently selected elements in the active view
set_parameter	Set a parameter value on an element
delete_elements	Delete elements with preview mode (set confirm=true to execute)

Views

Tool	Description
open_view	Open a view by ID or name
create_plan_view	Create a floor plan or ceiling plan for a level
create_elevation_view	Create an elevation at a location and direction
create_section_view	Create a section defined by origin, direction, and dimensions
create_schedule_view	Create a schedule for a category with optional field selection

Sheets

Tool	Description
create_sheet	Create a new sheet with a title block
add_view_to_sheet	Place a view on a sheet as a viewport

Model & Project

Tool	Description
get_project_info	Get project metadata (name, number, client, address, etc.)
analyze_model_statistics	Get element counts by category, family, type, and level
get_current_view_info	Get active view details (type, scale, detail level, etc.)
export_room_data	Extract rooms with area, volume, perimeter, and department data

Prerequisites

• Autodesk Revit 2025 (or newer)
• .NET 8 SDK — download here
• Claude Desktop or another MCP-compatible client

Building

Build the entire solution:

dotnet build RevitMcpServer.sln -c "Debug R25"

Build the server only:

dotnet build src/RevitMcp.Server/RevitMcp.Server.csproj

Publish the server for deployment:

dotnet publish src/RevitMcp.Server -c Release -o ./publish

The add-in's post-build step automatically copies the DLL and .addin manifest to Revit's add-in folder.

Setup

1. Install the Revit Add-in

Build the RevitMcp.Addin project with a Revit 2025 configuration (Debug R25 or Release R25). The post-build event copies the output to:

%APPDATA%\Autodesk\REVIT\Addins\2025\RevitMcp.Addin\

2. Configure Claude Desktop

Add the server to your Claude Desktop config (claude_desktop_config.json):

{
  "mcpServers": {
    "revit-mcp": {
      "command": "dotnet",
      "args": ["run", "--project", "C:\\path\\to\\src\\RevitMcp.Server\\RevitMcp.Server.csproj"]
    }
  }
}

Or if you've published the server:

{
  "mcpServers": {
    "revit-mcp": {
      "command": "C:\\path\\to\\publish\\RevitMcp.Server.exe"
    }
  }
}

3. Launch

1. Open Revit — the add-in loads automatically and starts the pipe server
2. Open Claude Desktop — it spawns the MCP server process on first tool call
3. The MCP Status button on the ribbon turns green when connected

Ribbon Buttons

The add-in creates a Revit MCP ribbon panel with four buttons:

Button	Action
MCP Status	Shows connection state, uptime, tool call stats, and last error
Restart Connection	Restarts the pipe server (fixes dropped connections or stuck requests)
Kill Server	Terminates the MCP server process (Claude Desktop respawns it automatically)
Open Claude	Launches Claude Desktop or brings it to the foreground

The MCP Status icon changes color based on connection state: green (connected), yellow (waiting), red (error).

Solution Structure

RevitMcpServer.sln
├── RevitMcp.Core/           Shared library (no MCP SDK or Revit UI dependency)
│   ├── Commands/            Command name constants
│   ├── Handlers/            ICommandHandler implementations (one per tool)
│   └── Messages/            BridgeRequest / BridgeResponse records
│
├── RevitMcp.Server/         MCP server (stdio transport, console app)
│   ├── Bridge/              Named pipe client (RevitBridgeClient)
│   └── Tools/               [McpServerToolType] tool definitions
│
└── RevitMcp.Addin/          Revit add-in (named pipe server, ribbon UI)
    ├── Bridge/              PipeServer, RequestChannel, ExternalEventExecutor
    ├── Status/              McpStatusTracker (connection state singleton)
    └── UI/                  Ribbon button commands

Adding a New Tool

1. Add the command name to RevitMcp.Core/Commands/CommandNames.cs
2. Create an ICommandHandler in RevitMcp.Core/Handlers/
3. Create or update a [McpServerToolType] class in RevitMcp.Server/Tools/
4. Register the handler in RevitMcp.Addin/App.cs

Key Design Decisions

• Named pipe bridge — The MCP server and Revit run in separate processes. A named pipe (revit-mcp-bridge) with 4-byte length-prefixed JSON framing connects them.
• ExternalEvent threading — All Revit API calls must run on Revit's main thread. Requests queue through a Channel<PendingRequest> and execute via ExternalEvent.
• System.Text.Json — Used everywhere for serialization. No Newtonsoft.Json dependency.
• Preview-mode deletes — delete_elements defaults to dry-run. The AI must explicitly set confirm=true to mutate the model.

License

All rights reserved.