Hexagonal Architecture Implementation¶

Overview¶

Anya Core implements a comprehensive hexagonal architecture pattern, emphasizing clean separation of concerns, domain-driven design, and modularity. This document details the implementation of the hexagonal architecture across the system, with a focus on Bitcoin Layer 2 integrations.

Core Architecture¶

Domain Layer¶

The domain layer contains the core business logic and rules, independent of external concerns:

// Core domain models
pub struct Transaction {
    id: TransactionId,
    inputs: Vec<Input>,
    outputs: Vec<Output>,
    witnesses: Vec<Witness>,
    metadata: TransactionMetadata
}

// Domain services
pub trait TransactionService {
    async fn validate(&self, tx: &Transaction) -> Result<ValidationResult>;
    async fn process(&self, tx: &Transaction) -> Result<ProcessingResult>;
    async fn verify(&self, tx: &Transaction) -> Result<VerificationResult>;
}

Application Layer (Ports)¶

The application layer defines the interfaces (ports) that the domain layer uses to interact with external systems:

// Input ports (primary/driving)
pub trait TransactionPort {
    async fn submit_transaction(&self, tx: Transaction) -> Result<TransactionId>;
    async fn get_transaction(&self, id: TransactionId) -> Result<Transaction>;
    async fn validate_transaction(&self, tx: &Transaction) -> Result<ValidationResult>;
}

// Output ports (secondary/driven)
pub trait BlockchainPort {
    async fn broadcast_transaction(&self, tx: &Transaction) -> Result<BroadcastResult>;
    async fn get_block(&self, hash: BlockHash) -> Result<Block>;
    async fn verify_proof(&self, proof: &Proof) -> Result<VerificationResult>;
}

Infrastructure Layer (Adapters)¶

The infrastructure layer implements the ports defined in the application layer:

// Bitcoin adapter implementation
pub struct BitcoinAdapter {
    rpc_client: BitcoinRpcClient,
    network: Network,
    config: BitcoinConfig
}

impl BlockchainPort for BitcoinAdapter {
    async fn broadcast_transaction(&self, tx: &Transaction) -> Result<BroadcastResult> {
        // Implementation
    }

    async fn get_block(&self, hash: BlockHash) -> Result<Block> {
        // Implementation
    }

    async fn verify_proof(&self, proof: &Proof) -> Result<VerificationResult> {
        // Implementation
    }
}

Layer 2 Protocol Integration¶

Protocol Adapters¶

Each Layer 2 protocol has its own adapter implementation:

// Protocol adapter trait
pub trait ProtocolAdapter {
    async fn submit_transaction(&self, tx: ProtocolTransaction) -> Result<TransactionId>;
    async fn verify_state(&self, state: &ProtocolState) -> Result<VerificationResult>;
    async fn sync_state(&self) -> Result<SyncResult>;
}

// BOB Protocol adapter
pub struct BobAdapter {
    rpc_client: BobRpcClient,
    state_manager: BobStateManager,
    verification: BobVerification
}

// RGB Protocol adapter
pub struct RgbAdapter {
    taproot_client: TaprootClient,
    asset_manager: RgbAssetManager,
    state_tracker: RgbStateTracker
}

// RSK Protocol adapter
pub struct RskAdapter {
    sidechain_client: RskClient,
    bridge_manager: RskBridgeManager,
    verification: RskVerification
}

Protocol Ports¶

Protocol-specific ports define the interfaces for each Layer 2 protocol:

// Protocol ports
pub trait ProtocolPort {
    async fn submit_protocol_tx(&self, tx: ProtocolTransaction) -> Result<TransactionId>;
    async fn verify_protocol_state(&self, state: &ProtocolState) -> Result<VerificationResult>;
    async fn sync_protocol_state(&self) -> Result<SyncResult>;
}

// Asset management ports
pub trait AssetPort {
    async fn issue_asset(&self, params: AssetParams) -> Result<AssetId>;
    async fn transfer_asset(&self, transfer: AssetTransfer) -> Result<TransferResult>;
    async fn get_asset_state(&self, asset_id: AssetId) -> Result<AssetState>;
}

Dependency Injection¶

The system uses dependency injection to wire up the hexagonal architecture:

// Dependency container
pub struct Container {
    bitcoin_adapter: Arc<BitcoinAdapter>,
    bob_adapter: Arc<BobAdapter>,
    rgb_adapter: Arc<RgbAdapter>,
    rsk_adapter: Arc<RskAdapter>
}

impl Container {
    pub fn new(config: Config) -> Self {
        // Initialize adapters
        let bitcoin_adapter = Arc::new(BitcoinAdapter::new(config.bitcoin.clone()));
        let bob_adapter = Arc::new(BobAdapter::new(config.bob.clone()));
        let rgb_adapter = Arc::new(RgbAdapter::new(config.rgb.clone()));
        let rsk_adapter = Arc::new(RskAdapter::new(config.rsk.clone()));

        Self {
            bitcoin_adapter,
            bob_adapter,
            rgb_adapter,
            rsk_adapter
        }
    }
}

Testing Strategy¶

The hexagonal architecture enables comprehensive testing at each layer:

#[cfg(test)]
mod tests {
    use super::*;

    // Domain layer tests
    #[tokio::test]
    async fn test_transaction_validation() {
        // Test implementation
    }

    // Port tests
    #[tokio::test]
    async fn test_protocol_port() {
        // Test implementation
    }

    // Adapter tests
    #[tokio::test]
    async fn test_bitcoin_adapter() {
        // Test implementation
    }
}

Monitoring and Metrics¶

The system includes comprehensive monitoring and metrics collection:

// Metrics collection
pub struct MetricsCollector {
    prometheus_client: PrometheusClient,
    metrics: Arc<RwLock<Metrics>>,
}

impl MetricsCollector {
    pub fn record_transaction(&self, tx: &Transaction) {
        // Record transaction metrics
    }

    pub fn record_protocol_state(&self, protocol: &str, state: &ProtocolState) {
        // Record protocol state metrics
    }
}

Error Handling¶

Error handling is implemented consistently across all layers:

// Error types
#[derive(Debug, Error)]
pub enum HexagonalError {
    #[error("Domain error: {0}")]
    Domain(String),

    #[error("Protocol error: {0}")]
    Protocol(String),

    #[error("Infrastructure error: {0}")]
    Infrastructure(String),
}

// Error context
pub struct ErrorContext {
    error: HexagonalError,
    severity: ErrorSeverity,
    trace_id: Option<String>,
    retry_count: u32,
    metrics: ErrorMetrics
}

Security Considerations¶

The hexagonal architecture ensures security at each layer:

1. Domain Layer
2. Business rule validation
3. State transition verification

4. Access control enforcement

5. Application Layer

6. Input validation
7. Output sanitization

8. Rate limiting

9. Infrastructure Layer

10. Secure communication
11. Authentication
12. Authorization

Performance Optimization¶

Performance optimizations are implemented at each layer:

1. Domain Layer
2. Efficient data structures
3. Caching strategies

4. Batch processing

5. Application Layer

6. Connection pooling
7. Request batching

8. Response caching

9. Infrastructure Layer

10. Load balancing
11. Circuit breaking
12. Retry strategies

Future Extensions¶

The hexagonal architecture supports easy extension for new protocols and features:

1. New Protocol Integration
2. Implement ProtocolPort
3. Create ProtocolAdapter

4. Add to dependency container

5. New Feature Addition

6. Define domain models
7. Create ports

8. Implement adapters

9. System Evolution

10. Version ports
11. Migrate adapters
12. Update dependencies

Bitcoin Layer 2 Integration¶

Protocol Compliance¶

The hexagonal architecture ensures compliance with Bitcoin standards and protocols:

// BIP compliance validation
pub trait BipCompliance {
    async fn validate_bip341(&self, tx: &Transaction) -> Result<ValidationResult>;
    async fn validate_bip342(&self, tx: &Transaction) -> Result<ValidationResult>;
    async fn validate_bip174(&self, psbt: &PartiallySignedTransaction) -> Result<ValidationResult>;
}

// Miniscript support
pub trait MiniscriptSupport {
    async fn compile_script(&self, policy: &Policy) -> Result<Script>;
    async fn analyze_script(&self, script: &Script) -> Result<ScriptAnalysis>;
}

Layer 2 Protocol Integration¶

Each Layer 2 protocol is integrated through dedicated adapters:

// BOB Protocol
impl ProtocolAdapter for BobAdapter {
    async fn submit_transaction(&self, tx: ProtocolTransaction) -> Result<TransactionId> {
        // Validate against BIP standards
        self.validate_bip341(&tx).await?;
        self.validate_bip342(&tx).await?;

        // Process transaction
        let result = self.process_transaction(tx).await?;

        // Record metrics
        self.metrics.record_transaction(&result);

        Ok(result.id)
    }
}

// RGB Protocol
impl ProtocolAdapter for RgbAdapter {
    async fn submit_transaction(&self, tx: ProtocolTransaction) -> Result<TransactionId> {
        // Validate Taproot requirements
        self.validate_taproot(&tx).await?;

        // Process asset transaction
        let result = self.process_asset_tx(tx).await?;

        // Update asset state
        self.update_asset_state(&result).await?;

        Ok(result.id)
    }
}

// RSK Protocol
impl ProtocolAdapter for RskAdapter {
    async fn submit_transaction(&self, tx: ProtocolTransaction) -> Result<TransactionId> {
        // Verify Bitcoin-backed state
        self.verify_bitcoin_backing(&tx).await?;

        // Process sidechain transaction
        let result = self.process_sidechain_tx(tx).await?;

        // Update bridge state
        self.update_bridge_state(&result).await?;

        Ok(result.id)
    }
}

Cross-Layer State Management¶

The system maintains consistent state across layers:

// Cross-layer state manager
pub struct CrossLayerStateManager {
    bitcoin_state: Arc<BitcoinState>,
    l2_states: Arc<RwLock<HashMap<ProtocolId, ProtocolState>>>,
    bridge_states: Arc<RwLock<HashMap<BridgeId, BridgeState>>>
}

impl CrossLayerStateManager {
    pub async fn sync_states(&self) -> Result<SyncResult> {
        // Sync Bitcoin state
        let bitcoin_state = self.sync_bitcoin_state().await?;

        // Sync Layer 2 states
        for (protocol_id, state) in self.l2_states.read().await.iter() {
            self.sync_protocol_state(protocol_id, state).await?;
        }

        // Sync bridge states
        for (bridge_id, state) in self.bridge_states.read().await.iter() {
            self.sync_bridge_state(bridge_id, state).await?;
        }

        Ok(SyncResult::Success)
    }
}

Compliance Requirements¶

BIP Standards¶

The system implements comprehensive BIP compliance:

1. BIP 341/342 (Taproot)
2. Taproot key path spending
3. Taproot script path spending
4. Taproot key aggregation

5. Taproot script verification

6. BIP 174 (PSBT)

7. PSBT creation and modification
8. PSBT validation
9. PSBT signing

10. PSBT finalization

11. Miniscript

12. Policy compilation
13. Script analysis
14. Witness generation
15. Script verification

Security Requirements¶

Security is enforced at each layer:

1. Transaction Security
2. Input validation
3. Output verification
4. Witness validation

5. Script verification

6. State Security

7. State transition validation
8. State consistency checks
9. State recovery mechanisms

10. State backup procedures

11. Protocol Security

12. Protocol-specific validation
13. Cross-layer verification
14. Bridge security
15. Fraud proof handling

Performance Requirements¶

Performance is optimized across layers:

1. Transaction Processing
2. Batch processing
3. Parallel validation
4. Caching strategies

5. Rate limiting

6. State Management

7. Efficient state storage
8. State synchronization
9. State recovery

10. State pruning

11. Protocol Operations

12. Protocol-specific optimizations
13. Cross-layer batching
14. Resource management
15. Load balancing

Monitoring and Alerts¶

The system includes comprehensive monitoring:

1. Protocol Metrics
2. Transaction throughput
3. State synchronization time
4. Validation latency

5. Error rates

6. Security Metrics

7. Validation failures
8. Security incidents
9. Fraud attempts

10. State inconsistencies

11. Performance Metrics

12. Resource utilization
13. Operation latency
14. Queue depths
15. Cache hit rates

Future Extensions¶

The architecture supports future protocol additions:

1. New Protocol Integration
2. Implement ProtocolAdapter
3. Add protocol-specific ports
4. Update dependency container

5. Add monitoring

6. Protocol Evolution

7. Version protocol adapters
8. Update validation rules
9. Enhance security measures

10. Optimize performance

11. System Enhancement

12. Add new features
13. Improve monitoring
14. Enhance security
15. Optimize performance

Last updated: 2025-06-02