# PolyLuthier

> Modal design for 3D-printed instruments, by Sunnyday Technologies LLC: calculated violin design studies and the Auxetivarius design preview.

## Free

- [PolyLuthier](https://polyluthier.com/): overview, the six calculated design studies as a table, method and limits.
- [Explorer](https://app.polyluthier.com/): the interactive mode viewer and 3D preview for people; the study runs and geometry load after a one-click human check.
- [Study summary](https://app.polyluthier.com/data/tradeoffs.json): trade-off summary of the six earlier-design studies (JSON).

## Paid: explore data for automated access

- PolyLuthier explore data, edition 2026-10-29-explore-r1. The six design-study runs, the summary and the Auxetivarius preview geometry as one zip (39.5 MB), 5.00 USDC on Base through x402. United States purchasers only.
- [Offer feed](https://polyluthier.com/agents.json): price, terms and checkout details for agents. Live status is confirmed at the gateway feed it names.
- [Purchase terms](https://polyluthier.com/terms/explore-data/2026-11-03/)
- License: CC BY-SA 4.0 (adaptations of Hovalin v5.1.0 and Printables model 104787). The payment covers automated delivery; it does not change the license.

Requests to app.polyluthier.com /data/ or /models/ without a human pass return HTTP 402 with the same offer.