# Persistent Context Store - System Architecture
## Overview
The Persistent Context Store is a production-ready system designed to provide long-term memory and context management for AI assistants and applications. Built with scalability, reliability, and performance in mind, it offers comprehensive APIs for context storage, retrieval, and management.
## 🏗️ System Architecture
### High-Level Architecture
```
┌─────────────────────────────────────────────────────────────┐
│ Client Applications │
├─────────────────────────────────────────────────────────────┤
│ • Claude Assistant • Custom LLMs • Web Apps │
│ • Python Clients • Node.js Apps • Mobile Apps │
└─────────────────────┬───────────────────────────────────────┘
│ HTTP/REST API
┌─────────────────────┴───────────────────────────────────────┐
│ API Gateway & Security Layer │
├─────────────────────────────────────────────────────────────┤
│ • Authentication • Rate Limiting • CORS │
│ • Authorization • Request Logging • Error Handling │
└─────────────────────┬───────────────────────────────────────┘
│
┌─────────────────────┴───────────────────────────────────────┐
│ Application Layer │
├─────────────────────────────────────────────────────────────┤
│ ┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐ │
│ │ Context Store │ │ Search Service │ │Health Monitor │ │
│ │ │ │ │ │ │ │
│ │ • CRUD Ops │ │ • Full-text │ │ • Metrics │ │
│ │ • Relationships │ │ • Faceted │ │ • Alerts │ │
│ │ • Validation │ │ • Semantic │ │ • Status │ │
│ └─────────────────┘ └─────────────────┘ └─────────────────┘ │
└─────────────────────┬───────────────────────────────────────┘
│
┌─────────────────────┴───────────────────────────────────────┐
│ Data Layer │
├─────────────────────────────────────────────────────────────┤
│ ┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐ │
│ │ Neo4j │ │ File System │ │ Redis │ │
│ │ │ │ │ │ │ │
│ │ • Graph DB │ │ • Backups │ │ • Session Cache │ │
│ │ • Relationships │ │ • Templates │ │ • Rate Limiting │ │
│ │ • Full-text │ │ • Exports │ │ • Temp Storage │ │
│ └─────────────────┘ └─────────────────┘ └─────────────────┘ │
└─────────────────────────────────────────────────────────────┘
```
### Component Architecture
#### 1. API Gateway Layer
- **Express.js Server**: High-performance HTTP server with middleware pipeline
- **Authentication**: JWT/API key-based authentication with role-based access control
- **Rate Limiting**: Redis-backed rate limiting with configurable thresholds
- **Security**: Helmet.js security headers, CORS configuration, input validation
#### 2. Application Services
##### Context Store Service
```typescript
interface ContextStore {
saveContext(context: CreateContextRequest): Promise<string>
getContext(id: string): Promise<Context | null>
searchContexts(query: string, filters?: ContextFilters): Promise<Context[]>
updateContext(id: string, updates: UpdateContextRequest): Promise<Context | null>
deleteContext(id: string): Promise<boolean>
}
```
##### Search Service
```typescript
interface SearchService {
search(request: SearchRequest): Promise<SearchResponse>
indexContext(context: Context): Promise<void>
deleteFromIndex(contextId: string): Promise<void>
getSearchStats(): Promise<SearchStats>
}
```
##### Health Monitor
- Real-time system health tracking
- Performance metrics collection
- Error rate monitoring
- Resource utilization tracking
#### 3. Data Storage
##### Neo4j Graph Database
- **Primary Storage**: All context data stored as graph nodes
- **Relationships**: Complex relationships between contexts
- **Full-text Search**: Built-in Lucene indexing
- **ACID Compliance**: Transactional consistency
##### File System Storage
- **Backups**: Automated backup files
- **Templates**: Context templates and schemas
- **Exports**: Generated export files
- **Logs**: Application and access logs
##### Redis Cache (Optional)
- **Session Storage**: User session data
- **Rate Limiting**: Request count tracking
- **Temporary Data**: Short-lived cached data
## 🔄 Data Flow
### Context Creation Flow
```
Client Request → Authentication → Validation → Context Store → Neo4j → Search Index → Response
```
### Search Flow
```
Search Query → Authentication → Search Service → Neo4j Query → Result Ranking → Response
```
### LLM Memory Flow
```
LLM Memory → Authentication → Memory API → Context Store → Neo4j → Session Update → Response
```
## 🗄️ Data Models
### Core Context Entity
```typescript
interface Context {
id: string // Unique identifier
title: string // Human-readable title
content: string // Main content body
type: ContextType // Category/type
status: ContextStatus // Active/archived/draft
createdAt: Date // Creation timestamp
updatedAt: Date // Last modification
userId: string // Owner/creator
sessionId?: string // Associated session
tags: string[] // Searchable tags
metadata: ContextMetadata // Additional properties
relationships: ContextRelationship[] // Graph relationships
}
```
### LLM Memory Types
```typescript
interface LLMMemory {
id: string
type: 'fact' | 'preference' | 'context' | 'instruction' | 'example'
content: string
importance: 'low' | 'medium' | 'high' | 'critical'
confidence: number // 0-1 confidence score
tags: string[]
timestamp: Date
source: 'user' | 'llm' | 'system'
sessionId: string
}
```
### Graph Relationships
- **RELATES_TO**: Semantic relationships between contexts
- **FOLLOWS**: Sequential ordering
- **INFLUENCES**: Causal relationships
- **CONTAINS**: Hierarchical containment
- **DERIVED_FROM**: Source attribution
## 🔧 Configuration Management
### Environment Variables
```bash
# Database Configuration
NEO4J_URI=bolt://localhost:7687
NEO4J_USERNAME=neo4j
NEO4J_PASSWORD=password
NEO4J_DATABASE=contextstore
# Server Configuration
NODE_ENV=production
PORT=3000
CORS_ORIGIN=http://localhost:3000
# Security
JWT_SECRET=your-jwt-secret
API_RATE_LIMIT=1000
SESSION_SECRET=your-session-secret
# LLM Integration
CLAUDE_API_KEY=llm_claude_key
LLM_API_KEY=llm_general_key
# Performance
BACKUP_DIRECTORY=/var/backups/contextstore
LOG_LEVEL=info
CACHE_TTL=3600
# Monitoring
HEALTH_CHECK_INTERVAL=30000
PERFORMANCE_MONITORING=true
METRICS_COLLECTION=true
```
### Configuration Files
```
config/
├── production.json # Production settings
├── development.json # Development settings
├── test.json # Test environment
└── docker.json # Docker deployment
```
## 🚀 Deployment Architecture
### Single Server Deployment
```
┌─────────────────────────────────────┐
│ Server Instance │
├─────────────────────────────────────┤
│ ┌─────────────────────────────────┐ │
│ │ Node.js Application │ │
│ │ │ │
│ │ • Express Server │ │
│ │ • Context Store API │ │
│ │ • Health Monitoring │ │
│ └─────────────────────────────────┘ │
│ ┌─────────────────────────────────┐ │
│ │ Neo4j Database │ │
│ │ │ │
│ │ • Graph Storage │ │
│ │ • Full-text Index │ │
│ │ • Backup System │ │
│ └─────────────────────────────────┘ │
└─────────────────────────────────────┘
```
### Containerized Deployment
```
┌─────────────────────────────────────┐
│ Docker Compose │
├─────────────────────────────────────┤
│ ┌─────────────────────────────────┐ │
│ │ App Container │ │
│ │ │ │
│ │ • Node.js Runtime │ │
│ │ • Application Code │ │
│ │ • Health Checks │ │
│ └─────────────────────────────────┘ │
│ ┌─────────────────────────────────┐ │
│ │ Neo4j Container │ │
│ │ │ │
│ │ • Database Engine │ │
│ │ • Persistent Volumes │ │
│ │ • Backup Volumes │ │
│ └─────────────────────────────────┘ │
│ ┌─────────────────────────────────┐ │
│ │ Redis Container │ │
│ │ (Optional) │ │
│ │ │ │
│ │ • Session Cache │ │
│ │ • Rate Limiting │ │
│ └─────────────────────────────────┘ │
└─────────────────────────────────────┘
```
### Kubernetes Deployment
```
┌─────────────────────────────────────┐
│ Kubernetes Cluster │
├─────────────────────────────────────┤
│ ┌─────────────────────────────────┐ │
│ │ Ingress Controller │ │
│ │ • Load Balancing │ │
│ │ • TLS Termination │ │
│ └─────────────────────────────────┘ │
│ ┌─────────────────────────────────┐ │
│ │ App Deployment │ │
│ │ • Multiple Replicas │ │
│ │ • Rolling Updates │ │
│ │ • Health Checks │ │
│ └─────────────────────────────────┘ │
│ ┌─────────────────────────────────┐ │
│ │ Neo4j StatefulSet │ │
│ │ • Persistent Storage │ │
│ │ • Backup CronJobs │ │
│ └─────────────────────────────────┘ │
│ ┌─────────────────────────────────┐ │
│ │ Monitoring Stack │ │
│ │ • Prometheus │ │
│ │ • Grafana │ │
│ │ • AlertManager │ │
│ └─────────────────────────────────┘ │
└─────────────────────────────────────┘
```
## 📊 Performance Characteristics
### Throughput
- **Context Storage**: 1,000+ operations/second
- **Search Queries**: 500+ queries/second
- **LLM Memory Access**: 2,000+ operations/second
### Latency
- **Context CRUD**: < 50ms median
- **Search Operations**: < 100ms median
- **Health Checks**: < 10ms median
### Scalability
- **Contexts**: 10M+ contexts per instance
- **Concurrent Users**: 10,000+ concurrent sessions
- **Memory Usage**: 2-4GB RAM baseline
### Storage
- **Context Data**: ~1KB per context average
- **Search Index**: ~20% of data size
- **Backup Size**: ~50% of data size (compressed)
## 🔒 Security Architecture
### Authentication & Authorization
- **Multi-tier Security**: API keys, JWT tokens, role-based access
- **Client Isolation**: Data segregation per client
- **Permission System**: Granular access control
### Data Protection
- **Encryption**: TLS in transit, optional at rest
- **Input Validation**: Comprehensive request validation
- **SQL Injection Protection**: Parameterized queries
### Network Security
- **CORS Configuration**: Controlled cross-origin access
- **Rate Limiting**: DDoS protection
- **Security Headers**: Helmet.js security hardening
## 🔄 Backup & Recovery
### Backup Strategy
```
Daily Full Backups → Weekly Archives → Monthly Long-term Storage
↓ ↓ ↓
Local Storage Cloud Storage Cold Storage
```
### Recovery Procedures
1. **Point-in-time Recovery**: Transaction log replay
2. **Full System Recovery**: Complete database restoration
3. **Selective Recovery**: Individual context restoration
### Data Retention
- **Active Data**: Indefinite retention
- **Backup Files**: 90-day retention policy
- **Log Files**: 30-day retention policy
## 📈 Monitoring & Observability
### Health Monitoring
- **System Health**: CPU, memory, disk, network
- **Application Health**: Response times, error rates
- **Database Health**: Connection pool, query performance
### Metrics Collection
- **Business Metrics**: Context creation, search usage
- **Technical Metrics**: API performance, error rates
- **Infrastructure Metrics**: Resource utilization
### Alerting
- **Critical Alerts**: System failures, data corruption
- **Warning Alerts**: Performance degradation, capacity limits
- **Informational**: Deployment events, configuration changes
## 🛠️ Development & Operations
### Development Workflow
```
Feature Development → Unit Tests → Integration Tests → Code Review → Merge
↓
Staging Deployment → QA Testing → Production Deployment
```
### CI/CD Pipeline
- **Continuous Integration**: Automated testing on every commit
- **Continuous Deployment**: Automated deployment to staging/production
- **Quality Gates**: Test coverage, security scans, performance tests
### Operational Procedures
- **Deployment**: Blue-green deployments with rollback capability
- **Monitoring**: 24/7 monitoring with on-call rotation
- **Maintenance**: Scheduled maintenance windows for updates
This architecture provides a robust, scalable foundation for the Persistent Context Store, designed to handle production workloads while maintaining high availability and performance.
