9 Apr 2026

End of AutoCAD 2021 Engine, New AutoCAD 2027 Engine Released

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What's New

We are excited to announce the release of the AutoCAD 2027 engine (Autodesk.AutoCAD+26_0) for Autodesk Platform Services Automation API for AutoCAD. This latest engine brings significant technical updates:

  • .NET 10.0 Platform: Modern .NET runtime
  • Visual Studio 2026: Latest tooling support
  • VC++ 145.0 Toolset: Updated C++ compiler for native plugins
  • CRX Registry Changes: Series updated from R25.1 (AutoCAD 2026) to R26.0 (AutoCAD 2027)

Important: AutoCAD 2021 Engine Deprecation

The AutoCAD 2021 engine (Autodesk.AutoCAD+24_0) for Automation API for AutoCAD is deprecated and will be removed from the service. After its removal, all workitems depending on this engine will cease to function as per our Engine Lifecycle Policy.

To ensure uninterrupted service, please migrate your application to a supported engine as soon as possible. We strongly recommend migrating to at least AutoCAD 2025 (Autodesk.AutoCAD+25_0) or the latest available engine, AutoCAD 2027 (Autodesk.AutoCAD+26_0), to maximize future compatibility and support.

Supported Engines for Migration

Engine Alias Initial Release Date Deprecation Date Removal Date
Autodesk.AutoCAD.24_1 March 30, 2021 March 29, 2025 March 29, 2027
Autodesk.AutoCAD.24_2 March 30, 2022 March 29, 2026 March 29, 2028
Autodesk.AutoCAD.24_3 March 30, 2023 March 29, 2027 March 29, 2029
Autodesk.AutoCAD.25_0 March 30, 2024 March 29, 2028 March 29, 2030
Autodesk.AutoCAD.25_1 March 30, 2025 March 29, 2029 March 29, 2031
Autodesk.AutoCAD.26_0 March 30, 2026 March 29, 2030 March 29, 2032

.NET Framework Migration Details

Depending on the engine you choose, please be aware of the underlying framework changes:

Migrating to 25_0 or 25_1 (AutoCAD 2025/2026)

These engines require .NET 8. You must update the SeriesMin and SeriesMax in your PackageContents.xml.

Migrating to 26_0 (AutoCAD 2027)

This engine requires .NET 10. You must update the SeriesMin and SeriesMax in your PackageContents.xml.

Migrating to 24_1, 24_2, or 24_3

These engines still use .NET Framework 4.8. Updating PackageContents.xml is optional, but we highly recommend migrating to at least 25_0 to stay current with the modern .NET architecture.

Migration Steps

AppBundle
  1. Create a new AppBundle version using POST appbundles/:id/versions. Make sure it points to the available engine.
  2. (Optional) Update and rebuild your plugin with the target version, update the supported SeriesMin and SeriesMax in PackageContents.xml, regenerate and upload the AppBundle. (Note: This step is mandatory if migrating to 25_0 or later).
  3. Assign the working alias to the new AppBundle version using PATCH appbundles/:id/aliases/:aliasId.
Activity
  1. Create a new Activity version using POST activities/:id/versions. Make sure it points to the available engine.
  2. Assign the working alias to the new Activity version by PATCH activities/:id/aliases/:aliasId.

Agentic Migration Helper Repository

To help you migrate your AutoCAD plugins, we have created a reference repository with working examples across different plugin technologies:

GitHub Repository: AutomationApps - Automation API for AutoCAD Bundles

This repository takes an agentic approach to migration, providing real working samples that you can use as templates or references for your own migration projects.

What's Included
Bundle Technology Description
TextExtractApp AutoLISP Extracts all TEXT/MTEXT entities from a drawing to result.txt
DumpDwgApp C++ CRX Dumps drawing database metadata (layers, blocks, text styles, etc.) to result.txt
XrefTraverserApp .NET 10 Traverses and reports the complete XRef hierarchy to result.txt
BatchPublishApp .NET 10 Batch publishes multiple DWG files to a single multi-page PDF

All four bundles are built for Autodesk.AutoCAD+26_0 (AutoCAD 2027) and include:

  • Complete source code with proper PackageContents.xml configuration
  • Local testing scripts (Run-*.ps1) for testing with your AutoCAD installation
  • Deployment scripts for Automation API for AutoCAD
  • SKILLS.md file for AI coding assistants with engine lifecycle, PackageContents.xml patterns, and API pitfalls
Using with AI Coding Assistants

The repository is designed to work with AI coding assistants like Claude, Cursor, and GitHub Copilot. The SKILLS.md file contains comprehensive patterns for:

  • Engine lifecycle and version selection
  • PackageContents.xml patterns for AutoCAD, Revit, Inventor, and 3ds Max
  • Activity commandLine templates
  • Bundle zip packaging rules
  • .NET Framework to .NET Core migration guide
  • Common API pitfalls not obvious from official documentation
Key Features for Migration

Technology Coverage: Whether you're working with AutoLISP, C++ CRX, or .NET, you have a concrete working example.

Modern .NET 10: The .NET bundles demonstrate proper migration from .NET Framework 4.8 to .NET 10, including project file structure, dependency management, and runtime configuration.

C++ CRX Updates: The DumpDwg sample shows the updated Visual Studio 2026 toolset (v145) and proper CRX registry settings for R26.0.

AutoLISP Bundle Structure: TextExtractApp demonstrates the correct bundle structure for LISP files, which differs from compiled plugins.

Hardcoded Output Patterns: All samples use hardcoded output filenames clearly documented in PackageContents.xml metadata, making them easy to integrate with automated workflows and MCP servers.

Migration Resources

For detailed guidance on migrating to .NET Core, please refer to the following resources:

Getting Started

To get started with the migration repository:

  1. Clone the repository: git clone https://github.com/ADN-DevTech/autocad-automation-apps
  2. Install prerequisites:
    • .NET 10 SDK
    • PowerShell 7+
    • Visual Studio 2026 with MSVC v145 toolset (for C++ CRX)
    • ObjectARX SDK 2027 (for C++ CRX)
  3. Build the samples: dotnet build AutomationApp.sln -c Release
  4. Configure APS credentials and run deployment scripts in the aps-da folder

Support

If you have questions about migrating to the new engine or need assistance, please:

Summary

The release of AutoCAD 2027 engine (Autodesk.AutoCAD+26_0) brings modern .NET 10 support and updated tooling. With the deprecation of AutoCAD 2021 engine, now is the time to plan your migration. Use the provided repository as a reference to understand the changes across different plugin technologies, and follow the migration steps to ensure your Automation API for AutoCAD workitems continue running smoothly.

Migrate early to take advantage of the latest features and extended support lifecycle.

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