DataDaddy

Verify your data. Mint proof. Lease it. Get paid.

DataDaddy is a privacy-first, on-chain data leasing protocol built on Base Sepolia. Users prove ownership of credentials (on-chain activity, ZK identity proofs, AI-verified documents) and lease time-bounded access to those credentials to buyers via escrow-based smart contracts with revocable access.

How it works

1. Verify — Users verify attributes about themselves via three tiers:

   • Tier 1 (on-chain, confidence 1.0): wallet activity scanned via Alchemy — defi_user, asset_holder, active_wallet, long_term_holder, nft_holder
   • Tier 2 (ZK, confidence 1.0): Anon Aadhaar zero-knowledge proof — age_range, state_of_residence
   • Tier 3 (AI document, confidence ≤0.99): GPT-4o scans an uploaded document for any custom attribute

2. Mint — Each verified attribute triggers minting of an ERC-5192 soulbound certificate on-chain (CertificateRegistry)

3. Match — Buyers post lease requests with attribute requirements and ETH escrow. Users with matching verified attributes see the requests on their dashboard.

4. Lease — Users approve matched requests on-chain (approveLease). ETH is held in escrow until the lease expires.

5. Settle — On expiry, settleLease releases ETH to the user. Permissionless — anyone can call it. Auto-settle runs on lease page load.

6. Revoke — Users can revoke any time, forfeiting their escrow payment.

Monorepo Structure

data-daddy/
├── packages/
│   ├── frontend/          # Next.js 16 — user & buyer UI (port 3001)
│   ├── backend/           # Next.js 16 API routes — verification, matching, delivery (port 3000)
│   └── contracts/         # Solidity 0.8.28 — CertificateRegistry + LeaseManager (Hardhat)
├── docs/                  # Architecture, decisions, env vars, done log
└── CLAUDE.md              # AI code-gen instructions (authoritative)

Quick Start

# Install all dependencies from repo root
pnpm install

# Terminal 1 — backend (port 3000)
cd packages/backend && pnpm dev

# Terminal 2 — frontend (port 3001)
cd packages/frontend && pnpm dev

Set up env vars in both packages/frontend/.env.local and packages/backend/.env.local. See docs/ENV_VARS.md.

Pages

Route	Description
/	Dashboard — verify wallet on-chain, see matched lease requests, approve
/leases	Lease history — active, settled, revoked; revoke/settle actions
/verify	ZK verification (Anon Aadhaar) + AI document verification
/buyer	Post lease requests on-chain, view approved users, access verified wallets
/stats	Personal stats — verified attributes, earnings breakdown, lease summary

Deployed Contracts (Base Sepolia)

Contract	Address
CertificateRegistry	0xBcF8f15E2c981663A08Db3878B994d65ddd84944
LeaseManager	0x1dEcC3fBa8fbc2eb04394Ac5cC6A9497BF9E7a00
AnonAadhaarZKVerifier	0xA205f7DED9430ac03b7F0CD3eA1b22C54C1A1453
MockAnonAadhaar	0x68AACB01AaeD9cAC1D46aD248F35cBd2F554F7D0

Chain ID: 84532 (Base Sepolia)

Docs

File	Purpose
docs/ARCHITECTURE.md	Full system design, API routes, data flow, trust boundaries
docs/CONTRACT_SPEC.md	Contract ABIs, events, function signatures, test checklist
docs/DECISIONS.md	Numbered architectural decision log (D-01 to D-27)
docs/ENV_VARS.md	All environment variables with source and setup instructions
docs/DONE.md	Completed feature log with commit references

Hi, Rashul here I did a ton of work on this project from Sthita's laptop. Just want credit here thanks <3