Loyalty Rewards That Protect Customer Privacy

Run reward programs where customer data never leaves your servers. Eligibility is verified on the blockchain using cryptographic proofs — so no personal information is ever exposed.

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How It Works

01
Keep Your Data
Your loyalty database — purchases, points, tiers — stays on your own servers. Nothing sensitive is uploaded.
02
Publish a Fingerprint
A compact cryptographic fingerprint (Merkle root) of your data is confirmed on the blockchain by network validators — every block.
03
Customers Prove Eligibility
Customers present a small piece of math (a Merkle proof) that shows they qualify — without revealing any personal details.
04
Unlock Rewards
Digital collectibles, tokens, or discounts are released automatically. Rewards are portable — usable across apps and blockchains.

Features

Customer Data Stays Private

The blockchain only ever sees cryptographic fingerprints and proofs — never names, emails, or account balances. Your customers' data remains under your control.

Rewards That Travel

Offer digital collectibles, tokens, or discount codes. Because rewards live on-chain, customers can carry them across apps, wallets, and platforms.

Always Up to Date

Network validators confirm a fresh snapshot of your data every block — so customers can claim rewards in real time, not after batch processing.

No Middleman Required

A smart contract checks every claim automatically. No one decides who qualifies — the math verifies it, so the process is transparent and tamper-proof.

Grows With Your Data

When your loyalty data changes — new purchases, updated tiers — a fresh fingerprint is published. Customers can claim against any confirmed snapshot, past or present.

Works With Any Database

PostgreSQL, MySQL, or any schema you already use. HashMerchant connects to your existing data — no migration required.

Under the Hood

Data flows from your database through a cryptographic pipeline to the blockchain. Here is how the pieces connect.

Your Database
PostgreSQL, MySQL, etc.
hash
Fingerprint
Merkle root
publish
Terp Chain
hashmerchant
module
route
Smart Contract
Verifier — checks Merkle proofs automatically
check
Customer Claims
Rewards unlocked

What a Claim Looks Like

When a customer claims a reward, this is the message sent to the blockchain. The proof shows eligibility without revealing any personal data.

{
  "claim_rewards": {
    "leaf_hash": "a1b2c3...",
    "proof": [
      { "sibling": "d4e5f6...", "is_right": true }
    ],
    "root_index": 0
  }
}

Open by Design

No Permission Needed

Anyone can publish a Merkle root and create a reward program. There is no approval process, no gatekeeping, no platform fee to get started. If you have a database and customers, you can launch a loyalty system today.

No Trust Required

Customers don't have to trust the company — and companies don't have to trust each other. The blockchain and the smart contract are the only arbiters. Every claim is verified by math, not by a middleman's decision.

Rewards That Stack

A local coffee roaster, a neighborhood co-op, and a national brand can each run their own program — and a customer who shops at all three can qualify for rewards across every one of them. Programs overlap naturally because they share the same verification layer, not because anyone signed a partnership deal.

Communities Curate, Customers Benefit

Vendors, brands, and communities each decide what to reward and how. A surf shop can offer collectibles to loyal locals. A DAO can unlock perks for active members. Because every program lives on the same chain, customers carry one identity across all of them — and new reward combinations emerge that no single company could design alone.