# Layered Architecture: The PayFi Stack

NEBULY’s design follows a six-layer vertical architecture, with each layer solving a specific pain point in real-world financial flows:

#### Transaction Layer

High-performance settlement

- Built on high-throughput L1s such as Solana, Stellar, and EVM-compatible chains for real-time execution
- Finality in under 1 second, sub-$0.001 fees
- Native support for recurring, multi-party, and tokenized payments

#### Currency Layer

Stable and programmable value

- Supports regulated stablecoins (e.g., USDC, PYUSD)
- Compatible with programmable stablecoin frameworks (e.g., Circle’s CCTP, PayPal's conditional disbursement model)
- Fiat-backed assets ensure price stability and off-chain interoperability

#### Custody Layer

Secure and decentralized asset management

- Employs multi-party computation (MPC) and smart contract escrow systems
- Integrates with providers like Fireblocks, Ledger, and protocol-native custody vaults
- Enables shared custody and multi-signer control without compromising transaction speed

#### Compliance Layer

Regulatory integration at the protocol level

- Embedded KYC/AML tools through Chainalysis, Polyflow, and identity bridges
- Support for soulbound tokens (SBTs) and decentralized identity (DID) standards (e.g., ERC-725, Verifiable Credentials)
- Enables jurisdiction-specific policy enforcement, blacklists, and sanctions compliance

#### Financing Layer

On-chain credit rails

- Automated underwriting using on-chain behavioral data, repayment history, and protocol-defined heuristics
- Credit scoring algorithms assign real-time risk tiers to income streams and borrowers
- Loan origination, distribution, and repayment fully governed by smart contracts
- Capital source-agnostic: retail LPs, DAOs, or institutional vaults

#### Application Layer

Modular Interfaces for Fintechs, DAOs, and Enterprise Finance

- Open APIs and SDKs to integrate NEBULY into fintech apps, DAOs, DePIN systems, and ERP platforms
- Supports modular UI components for invoicing, payroll, and embedded financing
- Enables seamless rollout of Web3-native financial products with compliance and infrastructure abstracted