In a landscape flooded with opaque AI wrappers, a new project called Closed is attempting to crack the mechanical design space by prioritizing auditability over blind automation. Launched on Hacker News on November 12, 2026, Closed is an AI agent specifically engineered for mould design, addressing a critical pain point for engineers: the inability to trust AI-generated geometry. The project, identified by the handle @ironfisto on X, positions itself not as a replacement for the designer, but as a drafting assistant that refuses to make silent decisions.

The Anti-Black-Box Architecture

The core differentiator of Closed is its insistence on provenance. Unlike generative tools that hallucinate dimensions, Closed logs every stage of the design processβ€”parting, core and cavity layout, feed, side actions, and ejectionβ€”with explicit source tracking. The platform categorizes every number into six distinct origins: measured by the CAD kernel, derived from shop rules, pulled from standard part catalogues, calculated by solvers, sourced from customer drawings, or manually typed by the user. Crucially, the AI itself is never listed as a source for a dimension, forcing the system to justify every millimeter.

Human-in-the-Loop Decision Making

Closed operates on a strict 'stop when the decision is yours' protocol. When the agent encounters a conflict, such as a bore running too close to an ejector pin, it does not silently adjust the geometry to fit. Instead, it pauses, presents three calculated fixes, recommends one, and waits for user input. The interface explicitly separates 'Reject' from 'Approve' to prevent accidental acceptance of unverified changes. This design philosophy acknowledges that while AI can draft, it cannot yet be trusted to assume liability for mechanical tolerances without human sign-off.

Seamless Handoff Between Modes

The tool supports a fluid transition between autonomous agent mode and manual editing. Users can take over the model at any point, modify values, and watch the validation checks update in real-time. Once the manual adjustments are complete, the agent resumes operation from the user's latest edit. The viewport mimics the navigation controls of industry-standard software like NX, SOLIDWORKS, or Creo, reducing the friction of adoption for veteran engineers who are skeptical of new AI interfaces.

Key Takeaways

  • Closed enforces provenance by ensuring no dimension originates directly from the AI model, only from CAD kernels, rules, catalogues, solvers, or users.
  • The agent pauses for explicit human approval when conflicts arise, offering three fix options rather than auto-correcting silently.
  • The software is currently in a pre-release state with a waitlist for macOS, Windows, iOS, and Android builds, with no immediate download available.

The Bottom Line

Closed understands that in engineering, trust is the bottleneck, not drafting speed. By making the AI’s work visible and reversible, it offers a pragmatic path to automation that respects the engineer's authority.