Note: If you cannot view the image, here is a summary: The diagram illustrates a payment flow: a Payment Intent is processed by a set of Aggregator nodes (which coordinate and route the transaction), which then interact with a network of Provision nodes (liquidity providers or processors). These nodes ultimately deliver funds to end users/recipients.
The Paycrest protocol is built on a modular, decentralized architecture that enables seamless stablecoin-to-fiat and fiat-to-stablecoin transactions. This section explains the core technical components and how they work together.
Core Components
Gateway Contract
The Gateway contract is the central entry point for all payment orders in the protocol.Key Functions
- Order Creation: Accepts payment orders from senders
- Order Validation: Validates order parameters and sender authorization
- Order Indexing: Emits events for aggregators to monitor
- Settlement Coordination: Manages onchain settlement processes
Order Lifecycle
1
Order Creation
Sender creates order via API or direct contract interaction
2
Liquidity Aggregation
Aggregator assigns order to suitable provider and coordinates liquidity
3
Fulfillment
Provider executes payment to recipient
4
Settlement
Onchain settlement and fee distribution
Aggregator Nodes
Aggregator nodes are high-availability services that coordinate the entire order routing process.Core Functions
- Order Monitoring: Monitor Gateway contract for new orders
- Provider Management: Maintain provider registry and ratings
- Order Matching: Match orders with optimal providers
- Settlement Coordination: Coordinate multi-provider settlements
- Compliance Verification: Verify KYC and regulatory compliance
Node Architecture
Blockchain Layer
- Event monitoring
- Transaction submission
- State synchronization
- Gas optimization
Business Logic Layer
- Order matching algorithms
- Provider selection logic
- Rate optimization
- Compliance checks
API Layer
- REST API endpoints
- WebSocket connections
- Webhook management
- Rate limiting
Data Layer
- Order database
- Provider registry
- Transaction logs
- Analytics data
Provision Nodes
Provision nodes handle the execution of payments to recipients.Components
- PSP Integration: Connect to local payment service providers
- Rate Management: Set and update competitive rates
- Order Processing: Execute assigned payment orders
- Settlement Reporting: Report successful settlements
- Compliance Monitoring: Monitor regulatory compliance
Integration Types
Bank APIs
- Direct bank integration
- SWIFT/SEPA transfers
- Real-time payments
- Batch processing
Mobile
- M-Pesa integration
- Airtel Money
- MTN Mobile Money
- Other mobile wallets
Crypto Exchanges
- OTC desk integration
- Exchange APIs
- Liquidity pools
- Automated trading
Payment Processors
- Stripe integration
- PayPal integration
- Local payment processors
- Digital wallets
Deployment Options
Provision Nodes can be deployed in two ways: Self-Hosted Deployment- Complete control over infrastructure
- Custom security configurations
- No dependency on third-party services
- Potential cost savings at scale
- Requires technical expertise for setup and maintenance
- One-click deployment through Blockops
- Automated scaling and monitoring
- Dedicated support and expertise
- Built-in security best practices
- Pay-as-you-use pricing model
- Recommended for most providers
Network Architecture
Multi-Chain Support
The protocol supports multiple blockchain networks for maximum flexibility.Supported Networks
- Base: Primary network for USDT/USDC transactions
- Polygon: Cost-effective transactions
- BNB Smart Chain: Binance ecosystem support
- Arbitrum One: High-performance L2 network
- Lisk: Alternative blockchain network
- Celo: Mobile-first blockchain
- Tron: USDT transactions
Network Selection
1
Sender Preference
Sender specifies preferred network
2
Provider Availability
Check provider support for network
3
Cost Optimization
Select network with lowest fees
4
Settlement Speed
Consider network confirmation times
Decentralized Infrastructure
The protocol operates on a decentralized infrastructure for reliability and censorship resistance.Node Distribution
- Geographic Distribution: Nodes distributed globally
- Provider Diversity: Multiple providers per region
- Redundancy: Multiple aggregators for reliability
- Failover: Automatic failover between nodes
Consensus Mechanism
- Order Assignment: Consensus on order provider assignment
- Rate Validation: Consensus on fair market rates
- Settlement Confirmation: Consensus on successful settlements
- Dispute Resolution: Consensus on dispute outcomes
Security Architecture
Smart Contract Security
The Gateway contract implements multiple security measures.Security Features
- Access Control: Role-based access control
- Rate Limiting: Prevent spam and abuse
- Emergency Pause: Ability to pause in emergencies
- Upgradeability: Controlled upgrade mechanism
- Audit Trail: Complete transaction audit trail
Vulnerability Mitigation
Reentrancy Protection
- Secure state management
- External call protection
- State validation
Overflow Protection
- Safe math operations
- Input validation
- Boundary checks
Access Control
- Role-based permissions
- Multi-signature support
- Time-locked operations
Data Integrity
- Hash verification
- Signature validation
- Merkle proof verification
Network Security
DDoS Protection
- Rate Limiting: API rate limiting per client
- Geographic Distribution: Global node distribution
- Load Balancing: Automatic load balancing
- Monitoring: Real-time attack detection
Data Protection
- Encryption: End-to-end encryption
- Privacy: Zero-knowledge proofs where applicable
- Compliance: GDPR and local privacy law compliance
- Audit: Regular security audits
Scalability Architecture
Horizontal Scaling
The protocol is designed for horizontal scaling across multiple dimensions.Scaling Dimensions
- Geographic Scaling: Add nodes in new regions
- Provider Scaling: Add more providers per region
- Network Scaling: Support additional blockchain networks
- Volume Scaling: Handle increased transaction volume
Performance Optimization
Database Optimization
- Read replicas
- Connection pooling
- Query optimization
- Caching layers
Network Optimization
- CDN distribution
- Edge computing
- Load balancing
- Caching strategies
Blockchain Optimization
- Gas optimization
- Batch processing
- Layer 2 scaling
- Cross-chain bridges
API Optimization
- GraphQL support
- Pagination
- Compression
- Caching headers
Integration Architecture
API Design
The protocol provides comprehensive APIs for all participant types.API Layers
1
Authentication Layer
API key management and validation
2
Rate Limiting Layer
Request throttling and quotas
3
Validation Layer
Input validation and sanitization
4
Business Logic Layer
Core business logic and rules
5
Data Layer
Database operations and caching
API Standards
- RESTful Design: Standard REST API conventions
- OpenAPI Specification: Complete API documentation
- Error Handling: Consistent error responses
- Versioning: API version management
- Deprecation: Graceful API deprecation
Monitoring and Observability
Metrics Collection
The protocol collects comprehensive metrics for monitoring and optimization.Key Metrics
- Transaction Volume: Orders per hour/day
- Success Rates: Order fulfillment success rates
- Latency: API response times and settlement times
- Error Rates: API error rates and types
- Provider Performance: Provider success rates and ratings
Monitoring Tools
- Application Monitoring: APM tools for performance tracking
- Infrastructure Monitoring: Server and network monitoring
- Business Metrics: Custom business intelligence dashboards
- Alerting: Proactive alerting for issues
Logging and Tracing
Logging Strategy
- Structured Logging: JSON-formatted logs
- Log Levels: Appropriate log level usage
- Log Aggregation: Centralized log collection
- Log Retention: Configurable log retention policies
Distributed Tracing
- Request Tracing: Track requests across services
- Performance Profiling: Identify performance bottlenecks
- Error Correlation: Correlate errors across services
- Dependency Mapping: Map service dependencies
Note: The Paycrest protocol architecture is designed for maximum reliability, scalability, and security while maintaining simplicity for developers and end users.