Scotec.Revit 2027.4.0-dev.4

Scotec.Revit

Core library for building robust, testable, and maintainable Autodesk Revit add-ins with .NET.

Overview

Scotec.Revit provides the foundational abstractions and infrastructure for Revit add-in development. It simplifies command execution, application lifecycle management, and background-to-Revit-context communication, while promoting clean architecture through dependency injection and service separation.

Key Features

• RevitCommand — Base class for IExternalCommand with built-in transaction management, a per-execution DI scope, and structured failure handling. Supports transaction modes: None, Transaction, TransactionGroup, TransactionWithRollback, TransactionGroupWithRollback, and ReadOnly.
• RevitApp / RevitAppBase / RevitDbApp — Base classes for IExternalApplication and IExternalDBApplication that wire up an IHost (Microsoft.Extensions.Hosting) for the add-in lifecycle, enabling full IoC container support via Autofac.
• RevitTask — Enables safe execution of Revit API operations from any thread or async context using the IExternalEventHandler mechanism. Supports both result-returning and void tasks, with optional DI parameter resolution.
• RevitEventHandler — Generic base class for subscribing to Revit application events with a per-invocation DI scope. Pre-built concrete handler bases are provided for all common document, application, and UI events.
• RevitCommandAvailability — Base class for IExternalCommandAvailability with DI scope per availability check, enabling ribbon button state to be driven by injected services.
• RevitHostBuilder — Configures the hosted application and registers Revit-specific services.
• RevitUpdater — Base support for IUpdater (dynamic model update) implementations.
• RevitSpatialContainmentResolver — Resolves spatial containment (rooms, spaces, zones).
• RevitLinkGraphBuilder — Builds a graph of Revit link relationships for traversal and analysis.
• RevitBasicFileInfo — Reads Revit file metadata without opening the document.

One Add-in per Assembly Load Context

Each RevitAppBase-derived application must run in its own AssemblyLoadContext. The framework stores the root DI service provider in a static field scoped to the load context, which means only one application instance is supported per context. Attempting to load a second application into the same context would silently overwrite the service provider, causing unpredictable behavior.

In practice this is not a restriction: every properly isolated add-in already runs in its own context. Use Scotec.Revit.Isolation to generate the required load context infrastructure automatically at compile time.

Getting Started

Install the NuGet package:

dotnet add package Scotec.Revit

Your project must target net8.0-windows or net10.0-windows.

Related Packages

• Scotec.Revit.Isolation
• Scotec.Revit.Ui
• Scotec.Revit.Wpf

Documentation

• RevitCommand
• RevitEventHandler
• RevitTask
• Revit Add-in Isolation

License

MIT License — https://licenses.nuget.org/MIT