Cardano L1 Blockchain Publisher

The Cardano L1 Blockchain Publisher is a specialized component of the Reeve platform that handles the publishing of financial transactions and reports to the Cardano blockchain. It ensures that all financial data is recorded immutably and transparently, leveraging the security and decentralization features of the Cardano network.

Overview

The Cardano L1 Publisher transforms validated financial transactions and reports from the Accounting Core module into a standardized on-chain format and publishes them to the Cardano blockchain. This ensures:

• Immutability: Financial records cannot be altered once recorded
• Transparency: All stakeholders can verify financial data independently
• Auditability: Complete audit trail of all transactions on the blockchain
• Decentralization: Records are stored across the Cardano network without single points of failure

On-Chain Format

Financial transactions and reports are published to the Cardano blockchain according to a standardized format that optimizes for both readability and blockchain storage efficiency.

For detailed specifications on the on-chain data format, field structures, and encoding specifications, please refer to the official documentation:

📖 On-Chain Format Documentation 

This document includes:

• Detailed schema definitions
• Transaction structure specifications
• Report encoding formats
• Data validation rules
• Examples of published transactions

Data Conversion & Optimization

The Cardano L1 Publisher applies several important transformations to financial data before publishing to the blockchain:

Cost Center Anonymization

To balance transparency with privacy requirements, the publisher replaces individual cost centers with their parent cost centers. This approach:

• Maintains visibility of higher-level organizational structure
• Prevents direct exposure of sensitive departmental/operational details on-chain
• Allows stakeholders to verify financial flows at the appropriate aggregation level
• Preserves full detailed data within the Reeve system for authorized access

Transaction Item Aggregation

To optimize blockchain storage and reduce transaction fees, transaction items are aggregated within the publisher when all fields are equal except the amount. In such cases:

• Multiple transaction items with identical accounts, cost centers, projects, and other attributes are combined
• The amounts are summed into a single aggregated transaction item
• This reduces on-chain data footprint without losing critical financial information
• The original granular data remains available within Reeve’s database for detailed reporting

Example Aggregation Scenario

Input Items:
├── Item 1: Debit 1001, Credit 2000, Cost Center A, Amount: 100
├── Item 2: Debit 1001, Credit 2000, Cost Center A, Amount: 50
└── Item 3: Debit 1001, Credit 2000, Cost Center A, Amount: 25

Aggregated Output:
└── Item: Debit 1001, Credit 2000, Cost Center A, Amount: 175

Publishing Process

The publishing process follows these steps:

1. Validation: Transactions are validated by the Accounting Core module
2. Transformation: Data is transformed according to the on-chain format specifications
3. Aggregation: Transaction items are aggregated where applicable
4. Serialization: Data is serialized for blockchain submission
5. Signing: Transactions are cryptographically signed
6. Submission: Signed transactions are submitted to the Cardano blockchain
7. Confirmation: Publishing status is tracked and updated as transactions are confirmed

Integration Points

The Cardano L1 Publisher receives validated transactions from:

• Accounting Core Module: Approved transactions ready for publishing
• Transaction Ledger Updates: Status updates of previously published transactions

The publisher emits events for:

• Publication Status: Notification of successful or failed publication attempts
• Transaction Confirmation: Updates when transactions are confirmed on-chain
• Batch Processing Status: Progress of batch publication operations

Security Considerations

• All transactions are cryptographically signed before submission
• Network communication uses secure protocols (HTTPS/TLS)
• Private keys for signing are managed securely
• Only validated and approved transactions are published

For more details on security implementation and best practices, refer to the architecture documentation.