SolidCraft: AI wrote a "free Fusion 360" that hit 14K stars in a month, promoted by makers on YouTube

SolidCraft is an open-source parametric 3D CAD written in pure Rust, aimed at Autodesk Fusion 360 and SolidWorks. It runs on desktop and in the browser, and ships with an MCP interface that lets AI model directly. The repo was created in Oct 7; by Nov 6 it had 14,095 stars and 1,869 forks. It rode the "AI clones paid big-company software" wave and was the first to take on the 3D mechanical CAD category. Below: what it is, where the stars came from, who it's competing with, and what you can learn from it if you want a project that gets stars too.

A 34k-subscriber channel's video, 840k views

2026 Oct 17, the maker channel Playduino posted a 13-minute video titled "First Adobe, Now Autodesk? SolidCraft Wants to Replace Fusion." The channel has only 33.8k subscribers. By Nov 6 the video had 840k views, 8,138 likes and 1,745 comments (YouTube, 11-06). The description contains only channel membership and gear affiliate links, with no sponsorship disclosure.

The most-liked comments weren't about how good the CAD is:

It's funny that the principle "we will replace you all with AI" can also work in the opposite direction. 1,704 likes. Autodesk deserves this more than anyone else. 1,169 likes. Companies are trying to use AI to replace humans. Now humans are using AI to replace companies. 814 likes

Others complained that Fusion is "a 10GB program, takes minutes to start, keeps forgetting my login, and forces updates" (599 likes). Another top comment with 239 likes read: "24 hours later: STEP import works now, and the icons all changed. They update too fast."

The day after the video went out, SolidCraft gained 829 stars in one day. The next three days were +1,291, +1,653, +1,246 (GitHub stars, day by day).

What it actually is

One line: an open-source, browser-based Fusion 360 that AI can operate directly.

• Parametric timeline. Sketch, add constraints, extrude, fillet, shell; every step is logged on the timeline, and changing one dimension rebuilds everything after it. The first thing in the README is a GIF: from a blank file, a Raspberry Pi 4 enclosure with holes, cooling slots and the text "Pi 4" carved in, then the height changes from 24mm to 32mm and the whole model rebuilds.
• Try it in seconds. Installers for Windows, macOS (signed and notarized) and Linux, plus a no-install web version.
• The UI and the AI use the same commands. Every action you take in the interface is a command with JSON parameters, so the same thing can run from the CLI, in scripts, or through the built-in MCP server to agents like Claude. Claude Code users add one config line to have AI draft parts for them.
• Calls itself "early." The README says "Early but usable for simple parts." Volume, area and centroid match for 76 of the public reference parts, 75 of them.

License is Apache-2.0. The author, bherbruck, initially published it under a personal account as SolveCraft, then created the Tangency Labs organization in Oct 16 and moved the library there. The code was mostly written by AI agents: 73 releases in one month and 3,513 merged PRs (GitHub, 11-06).

Where the stars came from

(GitHub stars; YouTube view count is 11-06.)

First, riding existing heat. In early October ArtCraft used AI to clone the Adobe suite. Tom's Hardware and How-To Geek covered it, "AI clones paid big-company software" became the tech topic of the month, and media and YouTubers were looking for the next installment. SolidCraft's name leans into the *Craft family, and the repo calls CADCraft a "sibling app." On Reddit's r/ArtCraftAI someone asked directly whether it would be merged into ArtCraft. Playduino's title, "First Adobe, Now Autodesk?", picks up that story directly.

Second, Show HN and trade press lit the fuse. In the HN comments someone recognized it uses the open-source kernel truck, and someone said "I tried FreeCAD's MCP and didn't like it at all." The Hackaday piece only covered what it can do and that it runs in the browser, with no mention of the AI-cloning angle. The top comment there was a cold splash of water: "Being written in Rust doesn't mean it can catch up with four decades of Parasolid." The second reply: "As long as it's more stable than SolidWorks, that's enough for me."

Third, YouTube was the main engine. The four days of fastest star growth (10-18 to 10-21) lined up with a cluster of more than a dozen review and tutorial videos. Most of these channels are maker channels for 3D printing, RC aircraft and CNC, whose viewers already use Fusion's free tier and have long complained about its subscriptions and logins. The videos could demo the product directly, the browser version let viewers follow along instantly, and viewers starred it after watching. None of the visible videos disclosed sponsorship; RB E-Motion specifically noted "no relationship with Autodesk or ArtCraft."

Fourth, fights broke out on Reddit. r/linux: "Linux gets another free powerful CAD"; r/FreeCAD: "SolidCraft is going to kill FreeCAD"; r/Fusion360: one side asking "Have you seen SolidCraft?" and the other saying "SolidCraft is hilariously bad." The arguing was itself exposure.

X was not the main channel. No meaningful spread on X was seen (unverified).

Who it's competing with

Open-source parametric 3D CAD used to mean FreeCAD alone, and it had a poor reputation. The position of "Fusion-style UI, free and open source, runs in the browser, AI can drive it" was empty before SolidCraft; now it holds it.

One more number is worth noting: CADCraft, which launched the same day with the same playbook, got only half the stars. The difference is audience: 3D modeling speaks directly to makers and 3D printing folks, while the 2D drafting audience is an order of magnitude smaller (inference).

What it still gets wrong

• How many people actually use it is unknown. In one month there were 7,564 issues, 4,213 still open, and many of them carry templated titles like "EXTRUDE: operation failed," which look like auto-reported errors from the app. Cumulative installer downloads are about 1.1M, but that includes auto-updates and isn't a user count.
• Many came for the buzz. Plenty of reviews say "hilariously bad" or "vibe coded so it's garbage," and the Hackaday comments question the kernel. The author is porting NVIDIA's SMLib kernel to Rust themselves (solidcore, 325 stars), which is a long road.
• Name squatters have already arrived. Sites like solidcraft.pro, solidcraft.online and solidcraftcad.com are competing for search traffic on the word "SolidCraft."
• The family is expanding. The same organization already has fieldcraft (simulation) and pcbcraft (circuit board design). The *Craft name is claiming the "AI clones industrial software" slots one by one.

If it were you

Bottom line: Don't build another open-source Fusion; that slot is now SolidCraft's. What's worth learning is the formula: pick a paid big-company tool that people complain about, where the open-source alternatives are hard to use; have an agent produce a demo-able full version in a few weeks; ship it while the topic is hot, and let vertical YouTube creators distribute it for you. The formula works, but it demands a lot in engineering effort and timing.

Who it fits: Developers who understand a specific professional tool and can judge "how complete does it have to be before users will try it"; people who can keep agents producing at high intensity for weeks and ship releases daily.

Who it doesn't fit: People who just want to rename and clone Fusion, AutoCAD or Photoshop once more; people who can't build a demo-able full version and only want to ship a half-finished product to ride the buzz. Things like B-rep modeling are, as one HN commenter put it, "a huge amount of work": SolidCraft merged over three thousand PRs in a month to reach "simple parts usable."

How to do it:

1. Pick a paid tool that hasn't been cloned yet. Search GitHub for "open source alternative to X," confirm there's no similar project with thousands of stars, then check whether the *Craft family has already claimed it. Good candidates are software with a large user base, high subscription costs, loud complaints, and a group of vertical video creators, such as building BIM, music production or engineering calculation tools (which niche is still open you'll have to check yourself; inference).
2. Fill the gap SolidCraft left. Its selling point is that AI can drive it, but nobody has yet clearly shown how well "one sentence produces a part" works. You could build an agent skill pack or part library dedicated to it (and to FreeCAD and OpenSCAD): parametric templates for common enclosures, brackets and gears, with a screen recording of "Claude makes a printable box in ten seconds." The hotter the host, the more readers you get.
3. Change the audience. Apply the same "free alternative + AI-driven" story to tools for a particular community (such as laser cutting, embroidery machines or small PCB workshops). The audience is smaller, but both creators and viewers are more concentrated (inference).

How to get stars: Put a GIF in the first screen of the README that goes from zero to a finished part and then rebuilds everything after one parameter change, and offer a no-install web version. Title it plainly as "A free open-source alternative to X" and tie it to the story everyone is discussing. After the Show HN, send the link directly to YouTube creators with tens of thousands of subscribers in that field. Playduino's 34k subscribers drew 840k views, which shows that this kind of audience eats up "kill the paid software" titles. Then ship every day, so the second wave of videos has a "fixed in 24 hours" story to tell.

When to move on: The "AI clones big-company software" wave started in October, and SolidCraft's daily star gains have already dropped from 1,653 to around 500. Your next category should launch this year. Once the buzz cools, the title just reads "yet another open-source alternative."

Signs you misread it: the software you picked already has open-source alternatives with a thousand stars; or your Show HN gets under 50 points, creators don't respond to outreach, and first-week stars stall in the hundreds. That means the software's users aren't angry enough, or your product isn't complete enough to make people click and want to try it. Time to switch categories.