OpenAI Build Week

OpenAI Build Week · Education · 1st place

Mechanica

Built by Weiying Zhu, Yukun Li, Shan Wei

Four ancient Chinese machines presented as interactive, source-cited 3D reconstructions, with a museum-grounded docent. The mechanisms are kinematic models; our checks found geometry and citation-rendering limitations.

I also participated in this hackathon with Trajectory. This coverage was prepared independently after results were announced.

The idea worth stealing

Mechanica made uncertainty a column.

Every dimension in the museum is tagged text-attested, artifact-measured, or inferred, and that tag survives all the way down: the 3D model, the validator, and the AI docent all read the same record. Ask the docent how much Su Song’s clock tower weighed and it says the sources don’t say, then points to the number they do give. Most “grounded” AI bolts citations onto answers after the fact. Mechanica put doubt in the schema, and the honesty followed.

What we checked

Date checked: .

Submission code, deployed museum and targeted docent checks; geometry and citation limits are described below.

Labels apply to each finding and the evidence described, not to the project as a whole.

Not independently verified means the available evidence was insufficient to confirm a claim. It does not mean the claim is false.

  1. The docent stays inside the evidence

    Verified

    We asked the live docent for the tower’s weight in kilograms. It declined, offered the attested “36 wheel cells” with a source marker, and stopped. The server hands GPT-5.6 the current machine’s record and nothing else. Source

  2. The provenance is real, not decorative

    Verified

    The clock tower’s 87 parts carry 203 per-dimension source labels, 89 of them marked inferred, and every quoted passage has a snapshot with a SHA-256 of the page it came from. Source

  3. The live site is the code, and the tests pass

    Verified

    A local build of the submitted commit matches the deployment byte for byte, and all 267 unit tests pass. Source

Under the hood

Quote receipts
Every passage cited from the Book of the Later Han or the History of Song has a snapshot file: the URL, the fetch time, hashes of the page and of the quote, and the matched span. The validator re-checks that the quote still resolves.
Rival reconstructions are overlays
Each machine is a base parts list plus scheme files that add or override parts. The seismoscope ships Wang Zhenduo’s and Feng Rui’s internal mechanisms as two overlays, swapped in place, and the validator sweeps each one separately.

Nuance

“Physically simulated” means kinematically simulated: the escapement is a stateful fill-release-lock cycle, not fluid dynamics. The geometry validator’s own reports record a handful of collision failures, which the builder’s notes acknowledge, and the nightly CI has never finished a full sweep. And in English the docent wrote [Source:…] where the interface expects [来源:…], so that one citation rendered as plain text.

Sources

Last updated: . Editorial updates do not imply a new technical check.

Builder credits reviewed: , using the official announcement, submission, and any linked credit sources.

Names supplied in an editorial correction. The linked Devpost submission still lists Caleb0796 wei, yukunl Li, and O Z.

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