Corobate · Attestation layer

Battery Digital Product Passport — from spec sheet to sealed receipt

A real input → receipt → transmit → reconstitute walkthrough. Everything runs in your browser; nothing is uploaded.

Step 1 — Open the field entry

This is the intake form for one product batch. Each row is a claim from the manufacturer's spec sheet. The passport is only as trustworthy as its weakest sufficiency-critical claim, so every row must declare where its evidence came from.

Product
VoltCore LFP-54 EV traction battery
Batch
LFP-2026-Q2-7741
Regime
EU Battery Regulation 2023/1542 — Digital Product Passport
Question
Can this battery's passport claims be attested as compliance-grade?

Step 2 — Input the field values

Prefilled from the datasheet. Change anything — a value, a provenance grade, a reliability, or whether a field is critical — then compute the receipt. Try setting a critical field to MISSING, or downgrading a VERIFIED claim to SELLER-ASSERTED, and watch the verdict move.

Field (claim)ValueProvenanceSource of evidenceReliab.Critical

Reliability is the calibrated trust in that kind of source. MISSING forces it to 0. The engine gates on the minimum reliability across the critical rows — the weakest link.

Step 3 — View the receipt

The engine graded every claim, gated on the weakest critical one, and sealed the result. This is the receipt — reproducible by anyone, tamper-evident.

Receipt JSON


    

Step 4 — Transmit or attach the receipt

The receipt travels with the product record. Download it, attach it to an email, or POST it to a registry / transparency log. The external RFC 3161 time anchor is added at issue time server-side; the content and chain you can verify anywhere, offline.

In production the same bytes are anchored to an RFC 3161 timestamp authority (freeTSA / DigiCert) and, optionally, appended to a public transparency log so a third party can prove the receipt existed at issue time.

Step 5 — Rebuild the receipt (prove it was kept intact)

Months later, pull the stored receipt and re-derive it from the retained fields. If the bytes were kept faithfully, the recomputed hashes match to the character — that is the proof of retention. Flip one byte and the seal breaks.

Want to check it against the standalone verifier? Open the receipt verifier → and paste the receipt from Step 3 — it runs the same five checks.

Worked illustration on a synthetic batch. It shows how EU Battery Regulation / Digital Product Passport claims are graded and sealed; it does not establish conformity for any real product. Not legal, financial, or compliance advice.