Harvest

A loyalty coalition protocol on Cardano. Multiple businesses form a coalition, each issuing voucher certificates to customers. Customers spend vouchers at any coalition member using zero-knowledge proofs.

One wallet, every loyalty program.

Why a coalition?

New members get instant foot traffic on day one — existing coalition users walk in and spend vouchers before the new member has issued a single certificate. Every redemption is a real sale. The coalition is the growth flywheel.

How it works

graph LR
    subgraph "Off-chain"
        U[User Phone] -->|ZK proof| R[Reificator]
        R -->|cap certificate| U
    end
    subgraph "On-chain"
        R -->|settlement tx| T[Trie Root UTXO]
        R -->|redemption tx| T
    end
    subgraph "Physical"
        U -->|certificate| R2[Reificator at Shop]
        R2 -->|discount| C[Casher]
        C -->|topup| R2
    end

Earning is off-chain (a signed certificate). Spending is on-chain (a Groth16 proof). Redeeming is physical (a screen lights up). Three domains, one protocol.

Documentation

• Semantics — precise definitions of every term in the protocol
• Actors — who participates and what they control
• Lifecycle — step-by-step protocol walkthrough with diagrams
• Security — threat model, cryptographic guarantees, attack analysis
• On-Chain State — three tries, UTXO structure, transaction types
• Cryptography — when signatures suffice, when ZK is needed
• Economics — who pays for what