Solana mainnet · SPL Memo · verifiable by anyone

The numbers can’t quietly change.

Every version of the methodology and of the code that computes the price per litre, the 3 layers and the recommendation becomes a SHA-256 hash. That hash is anchored on Solana. If anyone changes the rule later, the hash no longer matches.

This version

Methodology: docs/05-architecture/price-calculations.md6239423dcb2965f8e3a0620a5d12615bace6d39769bda8168de4b5d69189b01d
Calculation code: packages/domain/src/insights.ts + packages/domain/src/liquids.ts + packages/domain/src/burger.ts + packages/domain/src/volume.ts + packages/domain/src/text-readers.ts + packages/agent/src/menu-advisor.tsdf8627b2bda18ddc6391fbabae890f17161c5b04b893b9b3ca17dcc0462ede36
Commit: ed04cb0

# check it yourself, in the repository
sha256sum docs/05-architecture/price-calculations.md
cat packages/domain/src/insights.ts packages/domain/src/liquids.ts packages/domain/src/burger.ts packages/domain/src/volume.ts packages/domain/src/text-readers.ts packages/agent/src/menu-advisor.ts | sha256sum

Anchors on Solana

3NcV2SHo…1u5QaRaK · 11/10/2026 · commit 3d2843c · slot 455501588

Anchor this version

One SPL Memo transaction, signed by your wallet (Phantom) and sent through the site’s RPC. It moves no funds; it only costs the network fee (~0.000005 SOL).

UPAY3FOOD transparency v1 | methodology sha256:6239423dcb2965f8e3a0620a5d12615bace6d39769bda8168de4b5d69189b01d | engine sha256:df8627b2bda18ddc6391fbabae890f17161c5b04b893b9b3ca17dcc0462ede36 | commit ed04cb0

Why it matters

For users: the rule that says “the 700 ml is cheaper per litre” is public and cannot change behind their back.
For platforms: a comparison with objective, published criteria — what was missing in the Taxômetro case (99Food, 2026).
For regulators and researchers: future delivery price indexes can be verified batch by batch, the same way.

The anchor stores only hashes. No user price, address or personal data goes on-chain.