TLaaS (LEX) — License Metadata & Schema Registry Architecture

1. Purpose

Define a robust metadata and schema registry framework for TLaaS (LEX) licenses, enabling standardized, version-controlled, and machine-readable license data. Ensure compatibility with TLAAS (DLA) for compliance enforcement and DAL for governance-driven schema evolution.

2. Design Principles

• Interoperability: Metadata must be compatible with Web3 indexing protocols (e.g., The Graph) and off-chain systems.
• Version Control: Each schema update is recorded, signed, and linked to governance proposals.
• Extensibility: Support for custom fields without breaking core validation.
• Data Integrity: All metadata stored with cryptographic hashes for immutability.

3. Core Metadata Fields

{
  "licenseId": "0x123...",
  "licenseType": "broadcasting",
  "issuedAt": 1720560000,
  "expiresAt": 1752096000,
  "issuer": "0xABC...",
  "status": "Issued",
  "jurisdiction": "US-CA",
  "complianceRulesetVersion": "v1.2.0",
  "custom": {
    "field1": "value1",
    "field2": "value2"
  }
}

4. Schema Registry Contract (Solidity)

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract LicenseSchemaRegistry {
    struct Schema {
        string version;
        string ipfsHash; // IPFS CID for schema JSON
        uint256 registeredAt;
        address registeredBy;
    }

    mapping(string => Schema) public schemas; // key: licenseType

    event SchemaRegistered(string licenseType, string version, string ipfsHash);

    function registerSchema(string calldata licenseType, string calldata version, string calldata ipfsHash) external {
        schemas[licenseType] = Schema(version, ipfsHash, block.timestamp, msg.sender);
        emit SchemaRegistered(licenseType, version, ipfsHash);
    }

    function getSchema(string calldata licenseType) external view returns (Schema memory) {
        return schemas[licenseType];
    }
}

5. Off-Chain Storage & Hash Verification

• Store full schema JSON in IPFS or Arweave.
• Maintain SHA-256 or Keccak-256 hash in registry for verification.
• Validate schema before license issuance or renewal.

6. Schema Update Process

1. Proposal submitted via DAL.
2. Governance vote approves schema change.
3. Updated schema uploaded to IPFS/Arweave.
4. Registry contract updated with new CID and version.

7. Integration with TLAAS & DAL

• TLAAS (DLA): Uses schema to validate incoming license data.
• DAL: Controls schema lifecycle and approves new field additions.

8. Operational Runbook

• Validate schema format using JSON Schema validators.
• Regularly audit IPFS/Arweave pinning to ensure data persistence.
• Keep migration scripts for backward compatibility.

9. Acceptance Criteria

• 100% of licenses reference a valid schema version.
• All schema changes linked to governance decisions.
• Zero data integrity failures during validation.

Next Article: License Cryptographic Proof Anchoring & Audit Trail Mechanism