Why Cadre is free (and what an email unlocks)

Cadre is free. Not a trial, not a teaser with the good parts behind a paywall. You can open it in your browser, model a part, import an STL or OBJ, cut and combine geometry, check that a model is watertight, and watch the AI review tear into a sample design, all without an account.

Here is the honest version of where the line sits.

Free, no account

Open the editor and you get the whole modeling toolkit: parametric primitives, a 2D sketcher you can extrude or revolve, boolean operations, STL and OBJ import and export, version history you can roll back, and the printability checks the kernel computes right there in your tab. None of it is gated, and your file is never uploaded unless you ask it to be.

What an email unlocks

A few things genuinely need an account, and the account is a magic link sent to your email. No password, no credit card:

• The AI review on your own designs. Anyone can watch it review a built-in sample for free. Running it on the part you just modeled needs sign-in, because I pay for the inference and gate that one piece behind a real email.
• Cloud projects. Save a design to your account and pick it back up on another machine.
• Sharing and review. Generate a link so someone can open your model in their browser, turn it over, and leave suggestions that come back to you as parameter changes you accept or reject.

That is the whole deal. Free to build; an email when you want the AI on your own work, your projects saved, or a second set of eyes.

Why give the core away

Because the thing I am betting on is simple: once the review catches a wall you would have found only after a four-hour failed print, you will want it on everything. I would rather you find that out for free than read me claim it. Go model something and run the review on it. If you want the longer pitch first, here is how the review catches print failures before you slice.