# SANDSphere Tire Lifecycle Certificates (specimen)

> Demonstration service for the SANDSphere demo at democustomer.ai. Issues a "State of New York Tire Lifecycle Certificate" (specimen, Form TLC-1; not issued by or affiliated with New York State) as a TODA file, and moves it along a fixed custody chain between TODAQ twins. Each step is one Qatom catalog item at 0.010 USD-TDN, paid by the party releasing the certificate. Buy with agent_checkout.

Last updated: generated by the service on request.

## Chain
1. issue: created in sandsphere.certificatemint. Inputs: dot_tin (required, e.g. "DOT U2LL LMLR 4325"), size, tire_class, casing_grade (optional).
2. transfer mint-to-truckowner: certificatemint -> truckowner. Input: certificate (e.g. "NY-TLC-2026-000148").
3. transfer truckowner-to-retreader: truckowner -> retreader. Input: certificate (e.g. "NY-TLC-2026-000148").
4. transfer retreader-to-truckowner: retreader -> truckowner. Input: certificate (e.g. "NY-TLC-2026-000148").
5. transfer truckowner-to-recycler: truckowner -> recycler. Input: certificate (e.g. "NY-TLC-2026-000148").

Steps must run in order; the certificate closes at the recycler.

## Free
- https://certs.democustomer.ai/cert/{number}: the certificate page with its custody record.
- https://certs.democustomer.ai/cert/{number}.json: holder, step completed, next step, TODA file hash, every twist and Qatom transaction.

## Errors (answered as 200 with ok:false)
certificate_required, certificate_not_found, out_of_sequence (names the next item), not_holder, certificate_closed, busy, unknown_parameter, bad_value, twin_* (the twin refused; fee refundable).