ProofOS

Privacy-preserving crypto income and tax proofs for India

ProofOS turns wallet activity into verifiable financial claims without exposing your full transaction history.

Open Demo | Watch Video | Quick Start | Contracts

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Why this exists

Traditional reporting tools usually force a bad trade-off:

• Share full wallet dumps and lose privacy.
• Share summaries and lose credibility.

ProofOS removes that trade-off by combining deterministic Indian tax logic with on-chain verifiability.

Need	What ProofOS does
Loan eligibility proof	Prove threshold-based income claims without exposing raw ledger details
Visa or audit evidence	Produce tamper-evident tax and income certificates
Partner or investor trust	Offer cryptographic verification instead of spreadsheets

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What you can prove

• "My crypto income this year is above INR X"
• "My tax liability was computed as INR Y under encoded rules"
• "My net worth crossed INR Z"

All claims are generated from the same ledger commitment used for proof flow, then anchored for independent verification.

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Product flow

1) Connect wallet(s) on Base Sepolia
2) Ingest and normalize transfers
3) Compute tax using deterministic AY 2026-27 logic
4) Generate proof payload path on Starknet
5) Verify and anchor outcome to EVM verifier
6) Export certificate with verification metadata

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Core capabilities

• Privacy-first claim sharing (no raw wallet export required)
• India-focused tax engine with deterministic rule paths (Section 115BBH, Section 44ADA, rebate, surcharge, cess, marginal relief, and individual/HUF/corporate-compatible tracks)
• Multi-wallet workflows with ENS club integration
• Certificate generation with ledger commitment and verification references
• Optional decentralized publishing integrations (for configured environments)

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Architecture at a glance

flowchart LR
          A[Next.js Web App] --> B[API Routes]
          B --> C[Tax Engine in TypeScript]
          B --> D[Proof Job Flow]
          D --> E[Starknet Cairo Verifier]
          E --> F[Ethereum/Base-side Verification Record]
          F --> G[Certificate + Metadata Export]

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Stack

• Web: Next.js 16, React 18, Tailwind CSS 4
• Wallet and chain: RainbowKit, Wagmi, Starknet React
• Contracts: Solidity + Foundry, Cairo + Scarb
• Infra: Vercel, Alchemy, Starknet Sepolia, Base Sepolia

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Deployed contracts

Base Sepolia (chain id 84532)

These addresses are present in Foundry broadcast artifacts and return bytecode on Base Sepolia RPC.

• DemoToken: 0x121354bcaf7134f9477b61a0b45909db8a6b2807
• ProfitMachine: 0xabce611586bdb9eb18b79086d79dbea123dab6e0
• LossMachine: 0x1afb1765ea821c394d2459c4f40b267e3d86528b
• YieldFarm: 0x269127888e4adcaef8fb69ffd4bf5973b4c62de5
• TaxVerifier: 0x04c998dd105e444570ba1ecacb3f5524d5695aa0

Source artifact: contracts/broadcast/DeployBase.s.sol/84532/run-latest.json

Starknet and Ethereum Sepolia

• Starknet verifier and Ethereum verifier wiring are present in repo flow.
• Keep frontend env values aligned with the addresses you actively deploy.

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Quick start

Prerequisites

• Node.js 18+
• Foundry
• Scarb

1. Web app setup

cd apps/web
npm install
cp .env.local.example .env.local

PowerShell alternative:

Copy-Item .env.local.example .env.local

Fill required variables in .env.local:

NEXT_PUBLIC_WALLETCONNECT_PROJECT_ID=...
ALCHEMY_API_KEY=...
NEXT_PUBLIC_CAIRO_CONTRACT_ADDRESS=0x...
NEXT_PUBLIC_TAX_VERIFIER_ADDRESS=0x...

Run local app:

npm run dev

2. Contract environment setup

cd contracts
cp ../.env.example ../.env

PowerShell alternative:

Copy-Item ..\.env.example ..\.env

Then set values in .env as needed for deployment scripts.

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Deploy guide

EVM contracts (Foundry)

cd contracts
forge script script/DeployTaxVerifier.s.sol:DeployTaxVerifierScript \
     --rpc-url $SEPOLIA_RPC_URL \
     --broadcast

Cairo contracts (Scarb and Starkli)

cd contracts/starknet
scarb build
starkli declare target/dev/tax_verifier_TaxVerifier.contract_class.json
starkli deploy <class_hash>

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Repository map

ProofOS/
|- apps/
|  |- web/                  # Next.js UI + API routes
|- contracts/
|  |- src/                  # Solidity contracts
|  |- script/               # Foundry scripts
|  |- starknet/src/         # Cairo contracts
|- LICENSE
|- README.md

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Real-world scenarios

1. Home loan screening using privacy-preserving income proofs.
2. Visa and compliance packets with verifiable tax metadata.
3. Audit defense with deterministic recomputation trail.
4. Consolidated multi-wallet reporting for treasury or family office workflows.

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Security note

This is a hackathon-stage project and not legal or tax advice. Use with professional review before production or filing workflows.

Report sensitive issues privately instead of opening a public issue.

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License

MIT. See LICENSE.

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ProofOS

Because financial proof should be verifiable and private.