Feature Overview

RevitDevTool v3.0 is a development platform for .NET-based CAD/BIM applications. It supports Revit and AutoCAD-family hosts (2022–2027) and is designed to extend to any .NET-capable host. Iterate on automation code without rebuilding, reinstalling, or restarting the host.

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Four Pillars

Pillar	What it covers	Key entry points
Execution	CPython, IronPython, C# / F# scripts, .NET assemblies	Run Code Overview, Modern Python Scripting
Testing	pytest bridge + MTP TestAdapter for in-host tests	Testing Overview, pytest, NUnit, TUnit, MSTest
AI Tool Integration	Local MCP v2 clients via DevTools.Daemon.exe --stdio	MCP .NET, MCP Python
Logging	Log level, Monitor, File, and HTTP output + Revit geometry visualization	Log Level, Log Output, Geometry Visualization

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Claimed Hosts

RevitDevTool markets two host products. AutoCAD-family verticals (Architecture, MEP, Electrical, Mechanical, Map 3D, Civil 3D, Plant 3D, …) load the same AcadDevTool add-in — they are not separate product lines in this documentation.

Host	Versions	Status
Revit	2022–2027	Primary experience — full four pillars including geometry visualization
AutoCAD-family	2022–2027	Full execution, testing, MCP, and logging; no geometry visualization

Runtime callout — Plant 3D: the only current host with an embedded CPython runtime. PEP 723 dependencies install via a uv sidecar instead of Pixi. This is a Python backend exception, not a separate RevitDevTool product.

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Pillar Highlights

Execution

• CPython 3.14 via Pixi (default) with PEP 723 auto-install
• IronPython scripts and tests; on Revit, pyRevit engine preferred (default IronPython 2.7.12) — no debugger
• CPython debugpy + .NET IDE attach for compiled add-ins and Roslyn scripts
• C# / F# scripts via Roslyn; .NET assembly hot-reload

Testing

• PyTest bridge — CPython pytest and IronPython unittest run inside the selected host
• MTP TestAdapter — NUnit 5.0.0, TUnit 1.72.10, or MSTest 4.4.1 inside live hosts via RevitDevTool.TestAdapter 0.1.2
• --host revit, --host autocad, and other AutoCAD-family names; --force-launch, --per-test-timeout

AI Tool Integration

• Any local MCP v2 client (from 28 July 2026): Cursor, Claude Desktop, VS Code Copilot, ChatGPT Desktop, …
• Daemon entry: DevTools.Daemon.exe --stdio (replaces legacy MCPServer.exe)
• Built-in discovery tools + search_dynamic / invoke_dynamic for host-registered capabilities
• Custom Python and C# toolsets in Settings → MCP

Logging

• Three log sinks: Monitor (Trace Panel), file, HTTP
• Color keywords, pretty JSON, Python stack trace formatting
• Revit-only DirectContext3D geometry visualization (curves, faces, solids, meshes, points)

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What Changed From v2.x

• Four-pillar platform: shared DevTools.* libraries — execution, testing, MCP, and observability are not Revit-specific
• Two claimed hosts: Revit + AutoCAD-family (2022–2027); Revit 2027 adds .NET 10 target
• Python backends: Pixi-owned CPython 3.14 is the default; Plant 3D attaches to the host interpreter with a uv sidecar — v2's UV-only model is gone
• Unified state: sys.__devtool__ replaces host-specific attributes
• Daemon MCP server: DevTools.Daemon.exe --stdio with multi-host pipe discovery
• Testing as first-class pillar: pytest bridge + MTP TestAdapter, not buried under execution docs

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Best Starting Points

• New to the tool: Install And First Run
• Running Python: Modern Python Scripting
• Running compiled add-ins: Run .NET Add-ins
• Testing options: Testing Overview
• Connecting AI tools: MCP .NET or MCP Python
• Logs and geometry: Log Level
• AutoCAD-family workflows: AutoCAD Features
• Upgrading from v2.x: Migration To v3.0