AI CAD copilots: the assist pattern every vendor is chasing

Last Tuesday I was halfway through a surface patch in Fusion 360, the kind of repair job that happens when you import a STEP file from a supplier and discover the geometry has a gap the width of a human hair that the analysis tool insists is a canyon. The model was fine visually. The mesh preview was fine. But the moment I tried to shell it, the whole thing turned red and Fusion offered me an error message so vague it could have been a fortune cookie. So I opened Autodesk Assistant, typed "why is shell failing on this body," and waited.

The answer I got was a paragraph about shell operations in general. What they do, how they work, the kinds of geometry problems that cause them to fail. Perfectly accurate. Completely useless for my specific problem. I already knew what shell does. I needed the AI to look at my model, identify the bad face, and tell me where the issue was. It couldn't do that. None of them can, not yet. And that gap between what these copilots promise in the keynote and what they deliver at the desk is the story of AI CAD copilots in 2026.

The pattern everyone copied#

Every major CAD vendor has now shipped some version of the same idea: an AI assistant that lives inside the software, answers questions in natural language, and tries to help you work faster. The implementations vary, but the pattern is identical. A chat panel. A text input box. A system that pulls from documentation, training materials, and sometimes your model context. You ask a question, the AI answers, and occasionally it can trigger a command.

SolidWorks has AURA and LEO, introduced in the 2026 release as "virtual companions." Autodesk has Autodesk Assistant, available across Fusion 360 and other products. Onshape has AI Advisor. Siemens has Design Copilot in both NX and Solid Edge. PTC has the Creo AI Assistant, currently in beta. Even the second-tier and startup CAD tools are bolting on chat panels. The AI copilot has become table stakes, the feature no vendor wants to ship without, regardless of whether they've figured out what it's supposed to do.

The naming is all over the place, which tells you something. Assistant, Advisor, Companion, Copilot. Every vendor picked a word that implies the AI is helping, not doing. That's an accurate description of the current state, even if the marketing occasionally forgets to mention it.

What they can actually do#

Strip away the keynote demos and the launch blog posts, and the current generation of AI in CAD software copilots does roughly three things.

First, they answer how-to questions. "How do I create a loft between these two profiles?" "What's the difference between a shell and a thicken?" "How do I set up a static stress simulation?" The AI pulls from the vendor's documentation and training materials, packages the answer into a conversational format, and gives you links to the relevant help article. This is basically a better search engine for the help docs. And honestly, for a tool like SolidWorks or NX where the help documentation is vast and inconsistently organized, having an AI that can actually find the right article on the first try is genuinely useful. I've spent more time than I'll admit clicking through help menus that feel like they were organized by someone who lost interest halfway through.

Second, they can locate and sometimes launch commands. Autodesk Assistant can now execute Fusion commands if you describe what you want: "extrude this profile 10mm" or "add a 2mm fillet to the selected edges." SolidWorks LEO offers predictive command access based on what you're currently doing. Solid Edge's Design Copilot answers questions and provides guidance in natural language. This is the feature that feels closest to an actual productivity gain, because finding commands in a menu-heavy CAD tool is a real time sink, especially if you use the software intermittently and can't remember where Siemens hid the draft angle option this release.

Third, they provide design guidance. This is the vaguest category and the one vendors talk about most. AURA in SolidWorks is positioned as a "brainstorming partner" that connects you with enterprise knowledge and web resources. Onshape AI Advisor suggests best practices based on your conversation context. Creo AI Assistant helps with error troubleshooting by pulling from PTC's support knowledge base. The quality ranges from surprisingly helpful to aggressively generic, depending on how specific your question is and how well the vendor's knowledge base covers your problem.

What they can't do#

Here's the list that matters.

None of them can look at your model and understand what's wrong with it geometrically. They can tell you what kinds of problems cause a fillet to fail. They can't tell you which edge in your specific model is causing the failure and why.

None of them generate real geometry from scratch in the way text-to-CAD tools do. Autodesk has started moving in this direction with what they call "Neural CAD" in Assistant, where you can prompt for geometry creation, and it's available as a tech preview in Fusion as of March 2026. But the others are firmly in the "help you use the software" category rather than the "design things for you" category.

None of them reason about manufacturing constraints. You can ask how to set up a CAM toolpath, and the AI might walk you through the menus. You can't say "will this part be expensive to machine?" and get a useful answer based on your actual geometry.

None of them maintain real context across a session in a meaningful way. The context window is shallow and model-aware only in the most superficial sense. The AI knows you're in a Part environment or an Assembly environment. It doesn't know you've been fighting with the same tangent edge for twenty minutes.

And none of them reliably save time on the tasks where you actually need help. The easy questions, the ones the copilot answers well, are the ones you could have Googled in thirty seconds. The hard questions are precisely the ones the AI fumbles. That's the fundamental problem with the current copilot pattern: it's most capable when you need it least.

The vendor strategies diverge#

Despite the surface similarity, the vendors are making different bets.

Dassault Systèmes is going big with SolidWorks. AURA and LEO split the concept into two personas: AURA for knowledge exploration and creative guidance, LEO for practical design assistance like fixing broken references, automating assembly structures, and setting up simulations. LEO can detect problems and suggest fixes, which is closer to model-aware assistance than what most competitors offer. Both are available in the SolidWorks Labs beta as of the 2026 release.

Autodesk is pushing Autodesk Assistant the furthest toward actual geometry interaction. The text-to-command modeling feature, where you describe an operation in natural language and Assistant executes it in Fusion while preserving parametric history, is the most ambitious thing any vendor is shipping right now. It supports extrudes, fillets, chamfers, holes, shells, patterns, and revolves. It's also a tech preview, which in Autodesk language means "we think this works but please don't rely on it for Thursday's deadline."

PTC is taking the conservative route with Creo AI Assistant. The current beta focuses on error troubleshooting, pulling from PTC's support knowledge base to help you understand what went wrong. That's a narrower scope than what Dassault or Autodesk are attempting, but PTC's customer base skews toward large enterprises with regulated design processes, and those customers are more interested in reliability than flash. PTC's broader AI ambitions include natural language commands and predictive design recommendations in Creo 2026, but the current shipping product is modest.

Siemens splits its copilot across NX and Solid Edge. Design Copilot NX launched in mid-2025 with natural language query support and best-practice guidance. Solid Edge 2026 added its own Design Copilot built on RAG technology. Siemens also shipped AI features that aren't conversational: Magnetic Snap Assembly in Solid Edge uses AI to detect and apply mates automatically, and Select Similar Faces in NX uses AI to identify matching geometry across complex parts. These non-chatbot AI features are, in my experience, more immediately useful than the chat interfaces.

Onshape AI Advisor is the cleanest implementation from a usability standpoint. It's embedded in the workspace, pulls from Onshape's documentation and tutorial library, and focuses on helping users learn the tool. For people migrating from SolidWorks to Onshape, which is a common enough path these days, the AI Advisor is a genuinely useful guide. It doesn't try to be more than a smart documentation assistant, and because of that, it rarely disappoints.

The real competition isn't each other#

The thing about AI CAD copilots is that they're all competing with the same baseline: searching the help documentation yourself. And the help documentation, for most CAD tools, is actually pretty good. It's just badly organized and hard to search. A copilot that makes the existing docs more accessible is nice. It's not a revolution. It's a better index.

The tools that will actually change how people work are the ones that interact with the model, not just the menus. Autodesk is closest to this with the text-to-command features in Assistant. SolidWorks LEO's problem detection is another step in this direction. But until a copilot can look at my specific geometry, understand the design intent, and suggest a fix that accounts for the manufacturing process I'm targeting, the gap between the demo and the desk will remain.

For now, I use these copilots the way I use a pocket dictionary. Helpful when I've forgotten a word. Not helpful when I'm trying to write a novel. The real work still happens in the sketch, the feature tree, and the tolerance stack. The AI watches from the side panel, ready to explain things I already mostly know, while the problems I actually need solved sit there in red, waiting for a human.

Every vendor has an AI copilot now. Very few of them have figured out what it's for.