rvt-mcp

rvt-mcp is an open-source MCP server for Autodesk Revit published by the bimwright organization under the Apache-2.0 license. A .NET 8 server speaks MCP over stdio and connects to a thin add-in running inside Revit 2022–2027. The latest release listed is v1.2.0.

What It Is

rvt-mcp is a local bridge between an MCP client and a running Revit session. The server reaches the add-in over localhost TCP (Revit 2022–2024) or a named pipe (Revit 2025 and later). Per the README, nothing leaves the machine, and lengths are in millimetres at the tool boundary. Agents get a typed tool surface for common Revit work, plus a C# escape hatch (revit_send_code_to_revit) for tasks that no typed tool covers. Family Editor authoring is stated to be out of scope for now.

Tool Surface and Toolsets

The v1.2.0 release exposes 237 tools with all toolsets enabled, or 50 for a bare server (query, create, view, meta). Toolsets cover querying, creation, views and sheets, schedules, families, modification, annotation, export (PDF/DWG/IFC/NWC), MEP, graphics, materials, geometry, rooms, links, parameters, structural elements and composite workflows. A read-only mode filters out write-capable tools. Six MCP prompts guide the agent through getting started, drawing layout, change impact, model audit, pre-issue checks and stair creation.

Safety, Targets and ToolBaker

The server binds to a single Revit instance and requires explicit target and document confirmation before writes when several instances run. Controlled failure handling rolls back MCP warnings by default and records issues for review in the add-in History. An optional ToolBaker feature turns repeated patterns into personal tools; adaptive bake is off by default. The README warns that send_code runs arbitrary C# inside Revit and can be disabled.

Setup Path

Installation is Windows-focused. Users can have an AI agent follow AGENTS.md, or run the PowerShell installer, which registers the add-in for every detected Revit version and wires clients such as Claude Desktop or Claude Code. A Claude Desktop MCPB extension and a NuGet server package are also available. The add-in UI is offered in 15 languages.