PayShield

Compliance Middleware for Institutional Stablecoin Infrastructure

Think of PayShield as Stripe for regulatory compliance in DeFi. Drop in the SDK, wire up three hooks, and your protocol becomes instantly KYC-gated, transaction-monitored, AML-screened, and Travel Rule compliant — with all compliance receipts written on-chain for institutional audit.

Built for StableHacks 2026 — Tenity / AMINA Bank / Solana Foundation Track: Programmable Stablecoin Payments Demo Day: Zurich, April 8, 2026

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Architecture

payshield/
├── programs/                    # Solana Anchor programs (Rust)
│   ├── payshield_registry/      # KYC attestation store (PDA-based)
│   ├── payshield_gate/          # Transaction interceptor + compliance receipts
│   ├── payshield_audit/         # Immutable on-chain audit ledger
│   └── payshield_travel/        # VASP-to-VASP encrypted messaging
├── sdk/                         # TypeScript SDK (@payshield/solana)
│   └── src/
│       ├── kyc/                 # ZK identity proof verification
│       ├── kyt/                 # Real-time risk scoring (SIX Data API)
│       ├── aml/                 # Sanctions screening (OFAC/EU/UN/ChainPatrol)
│       └── travel-rule/         # FATF R.16 VASP messaging
├── dashboard/                   # Next.js compliance officer dashboard
└── demo/                        # Demo stablecoin payment app

Program IDs (Devnet)

Program	Address
payshield_registry	EhLH7HTooyBriCwz8GxFmCPc81fHmFqNqin81MnHbrar
payshield_gate	6o2E3EeK7rp7Zhpg15vD9M6evmaheb6CVWpGovLJrh8i
payshield_audit	86zhrrUTXf6ttctoSd5YA5xeJnBnhcxKhRv6rh7izUAM
payshield_travel	GRADVys4oCSh84eMethwXRQmhK9KNFnsczLkMi7TPugN

Quick Integration

import { PayShield } from "@payshield/solana";

const shield = new PayShield({
  network: "devnet",
  modules: ["kyc", "kyt", "aml", "travel_rule"]
});

// 1. Gate entry — verify KYC before any interaction
await shield.kyc.verify(userPublicKey);

// 2. Score transaction — KYT + AML check before settlement
const receipt = await shield.tx.screen(txDetails);

// 3. Attach receipt — Travel Rule metadata + on-chain audit record
await shield.tx.settle(transaction, receipt);

Compliance Coverage

Requirement	Implementation
KYC	ZK credential verification via payshield_registry; on-chain attestation with expiry and revocation
KYT	Pre-settlement risk scoring using SIX Data price feeds + on-chain velocity analysis
AML	Sanctions screening via ChainPatrol + OFAC/EU/UN; SAR flagging in audit trail
Travel Rule	Encrypted VASP-to-VASP messaging (FATF R.16) for transfers ≥ $1,000

Demo Scenario

Alice (Swiss resident) → Bob (German resident): 5,000 USDC

cd demo && npm run demo:alice-bob

Expected output:

[Step 1] KYC Verification — ZK identity proof check
  ✓ Alice KYC: VALID — Jurisdiction: CH, Tier: Enhanced
  ✓ Bob KYC: VALID — Jurisdiction: DE, Tier: Enhanced

[Step 3] KYT Risk Score
  ✓ Risk Score: 12/100 (LOW)

[Step 4] AML Screening
  ✓ OFAC SDN List: CLEAR
  ✓ EU Consolidated Sanctions: CLEAR
  ✓ UN Security Council Sanctions: CLEAR

[Step 5] Travel Rule (FATF R.16)
  ✓ Travel Rule applies (transfer ≥ $1,000)
  ✓ Encrypted VASP message sent: Alice-VASP → Bob-VASP

Verdict: ✓ APPROVED

Running Locally

Prerequisites

• Node.js 18+
• Rust + Cargo
• Anchor CLI 0.31+
• Solana CLI 1.18+

Build Solana Programs

# Generate lockfile with compatible cargo, then build
~/.cache/solana/v1.43/platform-tools/rust/bin/cargo generate-lockfile
# Downgrade lockfile version for SBF toolchain compatibility
python3 -c "
c = open('Cargo.lock').read().replace('version = 4','version = 3',1)
open('Cargo.lock','w').write(c)
"
cargo-build-sbf --tools-version v1.43 --workspace

Build SDK

cd sdk && npm install && npm run build

Run Dashboard

cd dashboard && npm install && npm run dev
# Open http://localhost:3000

Run Demo

cd demo && npm install && npm run demo

Privacy Architecture

• On-chain: Only credential hashes, compliance verdicts, and risk scores. No PII ever stored on-chain.
• Off-chain: KYC documents remain with the identity provider. PayShield receives only a signed ZK proof.
• Travel Rule: VASP-to-VASP messages are end-to-end encrypted (X25519 ECDH + AES-256-GCM).
• Audit trail: Compliance verdicts and timestamps only — sufficient for regulatory audit without exposing identity.

Success Metrics

• End-to-end compliance flow completes in < 3 seconds on Devnet
• KYC ZK proof verification costs < 10,000 compute units
• KYT risk score produced using live SIX Data FX feed (not mocked)
• Travel Rule VASP message encrypted and delivered within 1 block
• Compliance receipt visible in dashboard within 2 seconds
• Third-party protocol integrated using PayShield SDK in < 30 lines of code

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PayShield — Built for StableHacks 2026. The compliance primitive that Solana's stablecoin ecosystem is missing.