Revit MCP Project

This repository scaffolds an integration that keeps all Autodesk Revit API code inside a normal Revit add-in and exposes tools through a local MCP server.

The outer server speaks MCP over Streamable HTTP. The bridge and Revit-side handlers remain separate so the Revit API only executes inside Revit.

What Is In The Repo

src/
  RevitMcp.Contracts/
    BridgeRequest.cs
    BridgeResponse.cs

  RevitMcp.Core/
    Services/
      DocumentService.cs
      WallService.cs
      DuctPressureDropService.cs

  RevitMcp.RevitAddin/
    App.cs
    CommandDispatcher.cs
    Bridge/
      BridgeExternalEventHandler.cs
      BridgeRequestBroker.cs
      LocalHttpBridge.cs
    Handlers/
      IRevitCommandHandler.cs
      PingHandler.cs
      GetActiveDocumentHandler.cs
      ListWallsHandler.cs
      ColorizeDuctPressureDropHandler.cs
    Manifest/
      RevitMcp.RevitAddin.addin

  RevitMcp.Server/
    Program.cs
    BridgeClient.cs
    Tools/
      RevitTools.cs

Why The Shape Looks Like This

Revit API code must run inside the Revit process and on Revit-controlled execution.

Because of that:

• RevitMcp.RevitAddin owns every Revit API call.
• RevitMcp.Server stays outside Revit and exposes MCP tools only.
• BridgeRequestBroker marshals incoming bridge calls through Revit ExternalEvent instead of calling the API directly from the listener thread.

That last point matters. A naive HTTP listener thread cannot safely read or modify the active Revit document.

Supported Revit Versions

This project supports:

• Revit 2024 (.NET Framework 4.8)
• Revit 2025 (.NET 8)
• Revit 2026 (.NET 8)

The project files automatically select the correct target framework based on the RevitVersion build parameter. Revit 2025+ uses the modern .NET 8 runtime, while Revit 2024 uses .NET Framework 4.8.

Prerequisites

You need these on the machine where you will compile and run the add-in:

• Windows 10 or Windows 11
• Autodesk Revit 2024, 2025, or 2026
• .NET 10 SDK for the current server project target
• Visual Studio 2022 or another MSBuild-capable environment
• .NET Framework 4.8 Developer Pack (only required for Revit 2024 builds)

Revit References Required To Compile

The Revit projects use direct assembly references from the local Revit installation.

For RevitMcp.RevitAddin:

• RevitAPI.dll
• RevitAPIUI.dll

For RevitMcp.Core:

• RevitAPI.dll

Typical install folders:

C:\Program Files\Autodesk\Revit 2024\
C:\Program Files\Autodesk\Revit 2025\
C:\Program Files\Autodesk\Revit 2026\

The .csproj files already support either of these approaches:

1. Build by version:

dotnet build .\RevitMcp.sln /p:RevitVersion=2024
dotnet build .\RevitMcp.sln /p:RevitVersion=2025
dotnet build .\RevitMcp.sln /p:RevitVersion=2026

2. Build by explicit install folder:

dotnet build .\RevitMcp.sln /p:RevitInstallDir="C:\Program Files\Autodesk\Revit 2024"

If the DLLs are not found, the Revit projects fail early with a clear MSBuild error.

Where Dependencies Are Declared

Yes. The dependencies are written in the project files already.

• RevitMcp.sln only lists which projects belong to the solution and how they build together.
• .csproj files contain the real dependency declarations.

Current dependency shape:

• RevitMcp.RevitAddin.csproj
  • ProjectReference to RevitMcp.Contracts
  • ProjectReference to RevitMcp.Core
  • direct Reference to RevitAPI.dll
  • direct Reference to RevitAPIUI.dll
• RevitMcp.Core.csproj
  • direct Reference to RevitAPI.dll
• RevitMcp.Server.csproj
  • ProjectReference to RevitMcp.Contracts
  • PackageReference to ModelContextProtocol
  • PackageReference to ModelContextProtocol.AspNetCore
• RevitMcp.Contracts.csproj
  • PackageReference to System.Text.Json

The Revit projects still use direct DLL references from the local Revit i

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