PassLayer

PassLayer is a universal on-chain trust infrastructure that bridges asset issuers and investors in a unified compliant environment. We have built a Trust Layer that allows any business to tokenize assets, undergo verification (KYB + Asset Attestation), and instantly tap into a global pool of pre-verified users.
How it Works for Businesses (The "Single Window" Concept)
For any company issuing a Real-World Asset (RWA), PassLayer serves as a unified entry point:

1. KYB & Asset Attestation (Entry): A business completes a one-time verification via our KycSessionBroker. The Chainlink CRE worker validates the company's legal standing (KYB) and confirms the existence/value of the underlying asset.
2. Transparent Registry (AssetRegistry): Once verified, both the business and the asset are recorded in a unified, trusted registry. This provides an on-chain "seal of approval" that other protocols and investors can rely on.
3. Frictionless Market Access: Businesses no longer need to build their own siloed compliance systems. They simply check for existing "flags" in the PassRegistry to identify eligible investors across the entire ecosystem.
   The Problems PassLayer Solves
4. Dissolving Liquidity Walls
   The Problem: Today’s RWA market is a collection of "fragmented islands." A user verified on Platform A cannot buy an asset on Platform B without repeating the entire KYC process. This locks liquidity within individual platforms. The Solution: PassLayer removes these barriers. Thanks to portable attestations, users from different platforms can interact with any asset in the ecosystem. We turn fragmented markets into a unified liquidity pool.
5. Automating Issuer Trust
   The Problem: Investors are often hesitant to buy tokens from unfamiliar companies. Manual due diligence on an issuer is expensive, slow, and prone to error. The Solution: PassLayer automates institutional trust. If a business is listed in our registry, it means their KYB and asset data have been independently verified by the decentralized Chainlink network and our CRE worker.
6. Eliminating Compliance Friction
   The Problem: Businesses face massive operational overhead when storing sensitive personal data (PII) and navigating global regulations like GDPR. The Solution: We offload that burden. A business never has to see or store a user's passport. They simply query a smart contract to check for a bitflag. This provides Compliance-as-a-Service without the data liability.
   Key Summary Points:

• For Businesses: A single, trusted point of entry for asset listing and KYB verification.
• For Liquidity: Elimination of "islands" in the RWA market. Verified once, eligible everywhere.
• For the Ecosystem: A unified standard of trust where assets, issuers, and buyers are verified using the same transparent methodology.
• Technical Efficiency: Using bitflag structs allows for sub-second, low-gas compliance checks for both users and businesses in a single transaction.

PassLayer is built as a modular, on-chain compliance framework consisting of three logical layers, powered by a high-performance TypeScript/Solidity stack and Chainlink’s decentralized infrastructure.

1. The Logic: A Three-Layer Architecture
   We designed the system to dissolve "Liquidity Walls" by verifying three critical dimensions of trust without storing a single byte of PII (Personally Identifiable Information) on-chain.

• The User Layer: Focuses on removing barriers to entry. We support multi-provider verification (Sumsub, World ID/Proof-of-Humanhood, Persona). Instead of repeating KYC, a user is granted a "Portable Identity Flag."
• The Asset Layer: A unified Asset Registry that acts as a decentralized marketplace. It tracks the attestation status of tokenized assets, ensuring they are real, audited, and compliant.
• The Business Layer: A KYB (Know Your Business) Registry. This allows issuers to prove their legal standing and compliance status once, making them instantly "trustable" by the entire ecosystem.
  Privacy Note: We do not store verification data on the blockchain. Instead, we issue Bitflags (on-chain markers) that indicate a user, business, or asset has passed specific checks.

2. The Technical Stack (Implementation)
   PassLayer is organized as an NPM Workspaces monorepo, ensuring seamless interaction between our contracts, off-chain engine, and UI.
   Smart Contracts (The Backbone)

• PassRegistry.sol: The heart of the system. It stores on-chain attestations as composable bitflag structs. Using bitwise logic, we can record multiple verification levels (KYC, KYB, World ID) in a single, gas-efficient storage slot.
• KycSessionBroker.sol: Coordinates the verification lifecycle. It emits on-chain events that trigger the off-chain verification flow and tracks session ownership.
• AssetRegistry.sol: A gated marketplace where listing assets requires specific compliance flags. It enforces tiered access (e.g., Level 1 vs. Level 2 Access Pass).

Chainlink CRE Worker (The Engine)
Built in TypeScript with ethers.js v6, this worker is the "Trust Bridge":

1. Read: It polls the blockchain for KycRequested or AssetVerificationRequested events.
2. Compute: It orchestrates off-chain APIs (Sumsub/World ID). It handles secure key exchange using NaCl box (tweetnacl) to deliver encrypted SDK tokens to the frontend.
3. Write: Once verification is complete, it calls attestV2 on-chain to flip the compliance flags for the user or business.
   Frontend (The Interface)

• Tech: React 18 + Vite + wagmi/viem.
• UX: Uses WalletConnect (Reown AppKit) for a smooth connection. It features an embedded Sumsub WebSDK and World ID IDKit, allowing users to complete verification without ever leaving the app.

3. The Workflow (Putting it Together)
4. Interaction: A user or business initiates a request on the Frontend.
5. Trigger: KycSessionBroker emits an event on-chain.
6. Validation: The CRE Worker detects the event, validates the request via off-chain providers, and verifies the "Proof-of-Personhood."
7. Confirmation: The CRE Worker writes a signed attestation back to the PassRegistry.
8. Access: The user now holds a PassLayer Flag, granting them instant access to any asset in the AssetRegistry that matches their compliance level.

Build benefits:

• Gas Efficiency: Bitflags allow for sub-second, low-cost compliance checks.
• Zero Vendor Lock-in: The "Pluggable" nature means any new verification provider can be added to the CRE worker without changing the core on-chain logic.
• Scalability: By using Chainlink CRE, the system can handle thousands of concurrent verification sessions across multiple chains.