ERC-3643 tokenised fund infrastructure: smart contracts, identity, NAV oracles, mint/redeem flows, multi-chain deployment, and security model.
ERC-3643, also known as the T-REX (Token for Regulated EXchanges) Protocol, is a permissioned ERC-20 token standard with a built-in identity layer. It extends the standard ERC-20 interface to enforce transfer restrictions at the protocol level — every token transfer is validated against an on-chain compliance module before execution.
The standard was developed by Tokeny Solutions and became the first security token standard to receive ISO recognition. It is formally referenced in the ISO/TR 23455:2024 framework for blockchain-based securities.
| Standard | Permissioned | On-Chain ID | DeFi Compatible | Multi-Chain | Institutional Adoption |
|---|---|---|---|---|---|
| ERC-20 | No | No | Yes | Yes | Low |
| ERC-1400 | Yes | No | Limited | Limited | Medium |
| ERC-3643 | Yes | Yes (ONCHAINID) | Yes | Yes | High (BlackRock, Securitize) |
| ERC-3525 | No | No | Yes | Limited | Low |
transfer() and transferFrom() hooks that check the compliance module before every transfer executes.Each AQ segregated portfolio deploys its own token contract with shared identity infrastructure. The contract hierarchy below represents a complete deployment for a single fund token (e.g. AQ-YIELD).
ONCHAINID is the on-chain identity standard used by ERC-3643. Each investor deploys a lightweight identity proxy contract (ERC-735/ERC-734) that stores cryptographic attestations (claims) about their identity. Claims are signed by trusted issuers — the investor never reveals raw PII on-chain, only cryptographic proofs that they passed verification.
The ComplianceModule evaluates every transfer() and transferFrom() call. If any rule fails, the transaction reverts.
| Rule | Description | Enforcement |
|---|---|---|
| KYC Verification | Both sender and receiver must have valid KYC claims in the Identity Registry | On-chain — IdentityRegistry.isVerified() |
| Jurisdiction Whitelist | Transfers blocked to/from wallets linked to OFAC-sanctioned or restricted jurisdictions | On-chain — CountryModule |
| Accreditation Check | US investors must hold accredited investor claim (Reg D 506(c)). Non-US investors exempt under Reg S. | On-chain — ClaimTopics verification |
| Max Holder Count | Configurable limit on total unique holders per token (e.g. 99 for Reg D, 2000 for Reg A+) | On-chain — MaxHolderModule |
| Lock-Up Period | Tokens cannot be transferred within the lock-up window post-mint (e.g. 12 months for Reg D) | On-chain — TimeLockModule |
| AML Monitoring | Ongoing transaction monitoring with Chainalysis/Elliptic. Suspicious wallets can be frozen by ComplianceAgent. | Hybrid — off-chain monitoring, on-chain freeze |
| Component | Technology | Role |
|---|---|---|
| Smart Contracts | Solidity 0.8.x, ERC-3643 | Token issuance, compliance enforcement, NAV-based mint/redeem |
| Security Audit | Trail of Bits + Consensys Diligence | Dual audit — manual review (ToB) + automated + manual (Consensys) |
| Frontend | React / Next.js, wagmi, RainbowKit | AQ Portal — investor dashboard, KYC flow, subscription/redemption UI |
| Backend | Python (FastAPI) + Node.js | Subscription management, reporting, NAV ingestion, webhook handlers |
| KYC / AML | Sumsub | Identity verification, document checks, liveness detection, ongoing monitoring |
| On-Chain Identity | ONCHAINID (ERC-735 / ERC-734) | Wallet-level identity attestations, claim storage, trusted issuer verification |
| NAV Oracle | Chainlink Custom Feed | On-chain NAV publication, staleness protection, anomaly detection |
| Custody | Fireblocks / BitGo | Institutional-grade asset custody, MPC wallet infrastructure, policy engine |
| Transfer Agent | Securitize | Record keeping, ATS (Alternative Trading System) for secondary market, cap table |
| Fund Admin | Citco / NAV Consulting | Daily NAV calculation, investor record keeping, regulatory reporting |
| Monitoring | OpenZeppelin Defender | Contract monitoring, automated incident response, admin action proposals |
| Deployment | Hardhat + Safe (multi-sig) | Deterministic deployment, upgrade proposals, multi-sig admin operations |
| Role | Permissions | Holder |
|---|---|---|
| Owner | Upgrade contracts, grant/revoke roles, pause system, update registries | 3-of-5 Safe multi-sig |
| ComplianceAgent | Freeze wallets, update compliance modules, manage country lists, force transfers (recovery) | AQ Compliance Officer + Legal |
| NAVUpdater | Publish NAV updates (requires 2-of-3 multi-sig within the role) | Fund Admin + AQ Ops + Trustee |
| TransferAgent | Mint/burn tokens, process subscriptions/redemptions, manage investor records | Securitize platform + AQ Ops |
| Mechanism | Trigger | Action |
|---|---|---|
| NAV Circuit Breaker | NAV change exceeds ±5% from previous publication | Auto-pause mints/redeems. Require 3-of-5 override to resume. |
| Oracle Staleness | Latest NAV publication older than 48 hours | Auto-pause mints/redeems until fresh NAV published. |
| Rate Limiting | Single address exceeds mint/redeem threshold per period | Queue excess requests. ComplianceAgent manually reviews. |
| Emergency Pause | Any 1-of-5 multi-sig signer triggers emergency pause | All token transfers, mints, and redeems halted immediately. |
| Wallet Freeze | AML alert or sanctions match on a specific wallet | ComplianceAgent freezes wallet. Frozen tokens cannot be transferred. |