# Integration Architecture Specification

## Overview

This document defines the comprehensive integration architecture for the Gemini-Flow project, detailing how different components communicate, exchange data, and maintain consistency across module boundaries. The architecture supports the SPARC methodology requirements with emphasis on live API integration, scalability for 50K+ users, and robust error handling.

## Core Integration Principles

### 1. **Loose Coupling**
- Minimize direct dependencies between modules
- Use interfaces and contracts for communication
- Support independent deployment and scaling

### 2. **High Cohesion**
- Related functionality grouped within modules
- Clear separation of concerns
- Consistent error handling within module boundaries

### 3. **Event-Driven Communication**
- Asynchronous communication for scalability
- Event sourcing for auditability
- Publisher-subscriber patterns for loose coupling

### 4. **Contract-Based Integration**
- Explicit API contracts between modules
- Version management for interface evolution
- Comprehensive validation at boundaries

## Communication Patterns

### 1. **Synchronous Communication**

#### 1.1 Direct Method Calls
Used for high-performance, intra-process communication within the same service.

```typescript
// Example: Core service calling agent coordination
interface AgentService {
  coordinateAgents(request: CoordinationRequest): Promise<CoordinationResult>;
  getAgentStatus(agentId: string): Promise<AgentStatus>;
}
```

**Characteristics**:
- Low latency (<50ms)
- Direct coupling
- Immediate error handling
- Used within core business logic

#### 1.2 HTTP/REST API Calls
Used for cross-service communication and external integrations.

```typescript
interface RESTClient {
  post<T>(endpoint: string, data: any): Promise<T>;
  get<T>(endpoint: string): Promise<T>;
  put<T>(endpoint: string, data: any): Promise<T>;
  delete(endpoint: string): Promise<void>;
}
```

**Characteristics**:
- Standardized protocols
- Load balancing support
- Authentication/authorization
- Used for service-to-service communication

### 2. **Asynchronous Communication**

#### 2.1 Event-Driven Architecture
Primary pattern for inter-module communication and scalability.

```typescript
interface EventBus {
  publish(event: DomainEvent): Promise<void>;
  subscribe(eventType: string, handler: EventHandler): Subscription;
  unsubscribe(subscription: Subscription): Promise<void>;
}
```

**Event Types**:
- **Domain Events**: Business process state changes
- **Integration Events**: External system notifications
- **System Events**: Infrastructure and monitoring events

#### 2.2 Message Queue Pattern
Used for reliable, ordered message delivery between modules.

```typescript
interface MessageQueue {
  enqueue(queueName: string, message: Message): Promise<void>;
  dequeue(queueName: string): Promise<Message>;
  acknowledge(messageId: string): Promise<void>;
}
```

**Characteristics**:
- Guaranteed delivery
- Load leveling
- Failure isolation
- Used for high-throughput scenarios

### 3. **Streaming Communication**

#### 3.1 Real-time Data Streaming
Used for continuous data flow between components.

```typescript
interface StreamProcessor {
  processStream(stream: ReadableStream): AsyncIterable<ProcessedData>;
  createStream(data: any): ReadableStream;
  pipeStreams(source: ReadableStream, destination: WritableStream): Promise<void>;
}
```

**Characteristics**:
- Continuous data flow
- Low memory footprint
- Real-time processing
- Used for Google AI service integrations

## Protocol Integration Architecture

### 1. **Agent-to-Agent (A2A) Protocol Integration**

#### 1.1 A2A Message Flow
```
Agent Request → A2A Protocol Layer → Message Validation →
Routing → Agent Processing → Response → A2A Protocol Layer →
Response Delivery
```

#### 1.2 A2A Protocol Components

**Message Router**:
```typescript
interface A2AMessageRouter {
  routeMessage(message: A2AMessage): Promise<RoutingResult>;
  registerAgent(agentId: string, capabilities: AgentCapabilities): Promise<void>;
  unregisterAgent(agentId: string): Promise<void>;
  getRoutingTable(): RoutingTable;
}
```

**Message Format**:
```typescript
interface A2AMessage {
  id: string;
  sourceAgent: string;
  targetAgent: string;
  messageType: A2AMessageType;
  payload: any;
  metadata: MessageMetadata;
  security: SecurityContext;
  timestamp: number;
}
```

#### 1.3 A2A Integration Points

**Core Services Integration**:
- Agent coordination service
- Protocol translation layer
- Security enforcement layer

**External Systems Integration**:
- MCP server bridge
- Google AI services adapter
- Storage layer integration

### 2. **Model Context Protocol (MCP) Integration**

#### 2.1 MCP Server Architecture
```
Client Request → MCP Client → Protocol Translation →
MCP Server → Tool Execution → Response → Protocol Translation →
Client Response
```

#### 2.2 MCP Integration Components

**MCP Client**:
```typescript
interface MCPClient {
  connect(serverConfig: MCPServerConfig): Promise<Connection>;
  disconnect(): Promise<void>;
  callTool(toolName: string, parameters: any): Promise<ToolResult>;
  listAvailableTools(): Promise<ToolInfo[]>;
}
```

**MCP Server**:
```typescript
interface MCPServer {
  start(config: ServerConfig): Promise<void>;
  stop(): Promise<void>;
  registerTool(tool: ToolDefinition): Promise<void>;
  handleRequest(request: MCPRequest): Promise<MCPResponse>;
}
```

#### 2.3 MCP Integration Points

**Tool Integration**:
- Google AI service tools
- File system operations
- Database operations
- Network utilities

**Context Management**:
- Session management
- State persistence
- Context sharing

### 3. **Google AI Services Integration**

#### 3.1 Service Integration Architecture
```
Request → Service Router → Authentication → Rate Limiting →
Service Client → Google AI API → Response Processing →
Response → Client
```

#### 3.2 Integration Components

**Service Client**:
```typescript
interface GoogleAIServiceClient {
  generateText(request: TextGenerationRequest): Promise<TextGenerationResult>;
  generateImage(request: ImageGenerationRequest): Promise<ImageGenerationResult>;
  generateVideo(request: VideoGenerationRequest): Promise<VideoGenerationResult>;
  streamContent(request: StreamingRequest): AsyncIterable<StreamingResult>;
}
```

**Authentication Handler**:
```typescript
interface GoogleAIAuthHandler {
  authenticate(credentials: GoogleAICredentials): Promise<AuthToken>;
  refreshToken(token: AuthToken): Promise<AuthToken>;
  validateToken(token: AuthToken): Promise<TokenValidationResult>;
}
```

## Data Flow Architecture

### 1. **Request-Response Data Flow**

#### 1.1 Internal Request Flow
```
CLI/API Request → Input Validation → Service Orchestration →
Domain Logic → External Service → Response Processing →
Formatted Response → Client
```

#### 1.2 External Service Integration Flow
```
Service Request → Protocol Translation → Authentication →
External API Call → Response Translation → Data Mapping →
Domain Response → Client
```

### 2. **Event-Driven Data Flow**

#### 2.1 Event Publishing Flow
```
Business Event → Event Creation → Event Enrichment →
Event Publishing → Event Bus → Event Routing → Event Handler
```

#### 2.2 Event Processing Flow
```
Event Reception → Event Validation → Event Processing →
Side Effects → Event Acknowledgment → Monitoring
```

### 3. **Streaming Data Flow**

#### 3.1 Continuous Data Streaming
```
Data Source → Stream Creation → Data Transformation →
Stream Processing → Result Streaming → Client Consumption
```

#### 3.2 Batch Processing Flow
```
Data Collection → Batch Formation → Processing Pipeline →
Result Aggregation → Output Delivery
```

## Integration Testing Architecture

### 1. **Testing Strategy Overview**

**Live API Testing Requirement**: All integration tests must use real external services and APIs, no mocks allowed.

#### 1.1 Test Environment Architecture
```
Test Environment → Service Instances → External APIs →
Database → Message Queue → Monitoring → Test Orchestrator
```

#### 1.2 Integration Test Categories

**Component Integration Tests**:
- Test individual component interactions
- Validate API contracts
- Ensure data consistency

**System Integration Tests**:
- Test end-to-end workflows
- Validate cross-module communication
- Ensure system reliability

**Performance Integration Tests**:
- Test under realistic load conditions
- Validate scalability characteristics
- Ensure performance SLAs

### 2. **Test Data Management**

#### 2.1 Live Data Strategy
```typescript
interface LiveTestDataManager {
  createTestData(data: TestDataSpec): Promise<TestData>;
  cleanupTestData(dataId: string): Promise<void>;
  validateTestData(data: TestData): Promise<ValidationResult>;
}
```

#### 2.2 Data Isolation
- Separate test environments for each test suite
- Unique identifiers for all test data
- Automatic cleanup after test completion
- Data validation before and after tests

### 3. **Test Orchestration**

#### 3.1 Test Execution Framework
```typescript
interface IntegrationTestOrchestrator {
  setupTestEnvironment(config: TestConfig): Promise<TestEnvironment>;
  executeTestSuite(suite: TestSuite): Promise<TestResult>;
  teardownTestEnvironment(): Promise<void>;
  collectTestMetrics(): Promise<TestMetrics>;
}
```

#### 3.2 Test Reporting
- Real-time test execution monitoring
- Comprehensive test result reporting
- Performance metrics collection
- Failure analysis and debugging support

## API Contract Management

### 1. **Contract Definition**

#### 1.1 Interface Contracts
```typescript
interface APIContract {
  name: string;
  version: string;
  description: string;
  endpoints: EndpointDefinition[];
  dataTypes: DataTypeDefinition[];
  errorCodes: ErrorCodeDefinition[];
}
```

#### 1.2 Contract Validation
```typescript
interface ContractValidator {
  validateImplementation(contract: APIContract): Promise<ValidationResult>;
  validateCompatibility(contract1: APIContract, contract2: APIContract): Promise<CompatibilityResult>;
  generateContractDocumentation(contract: APIContract): Promise<Documentation>;
}
```

### 2. **Version Management**

#### 2.1 Versioning Strategy
- Semantic versioning for all APIs
- Backward compatibility requirements
- Deprecation policies
- Migration support

#### 2.2 Version Negotiation
```typescript
interface VersionNegotiator {
  negotiateVersion(clientVersion: string, serverVersion: string): Promise<VersionAgreement>;
  validateVersionCompatibility(clientVersion: string, serverVersion: string): Promise<boolean>;
  getVersionMigrationPath(fromVersion: string, toVersion: string): Promise<MigrationPath>;
}
```

## Cross-Cutting Concerns Integration

### 1. **Security Integration**

#### 1.1 Authentication Integration
- Single sign-on across all modules
- Token-based authentication
- Session management
- Access control enforcement

#### 1.2 Authorization Integration
- Role-based access control
- Attribute-based access control
- Policy enforcement points
- Audit logging

### 2. **Monitoring Integration**

#### 2.1 Metrics Collection
- Standardized metrics format
- Centralized metrics aggregation
- Real-time monitoring
- Alert generation

#### 2.2 Logging Integration
- Structured logging across modules
- Centralized log aggregation
- Log correlation across services
- Performance impact monitoring

### 3. **Tracing Integration**

#### 3.1 Distributed Tracing
- Request correlation across modules
- Performance bottleneck identification
- Error tracking and analysis
- Service dependency mapping

## Error Handling Architecture

### 1. **Error Classification**

#### 1.1 Error Types
```typescript
enum ErrorType {
  VALIDATION_ERROR = 'VALIDATION_ERROR',
  AUTHENTICATION_ERROR = 'AUTHENTICATION_ERROR',
  AUTHORIZATION_ERROR = 'AUTHORIZATION_ERROR',
  BUSINESS_LOGIC_ERROR = 'BUSINESS_LOGIC_ERROR',
  EXTERNAL_SERVICE_ERROR = 'EXTERNAL_SERVICE_ERROR',
  INFRASTRUCTURE_ERROR = 'INFRASTRUCTURE_ERROR',
  TIMEOUT_ERROR = 'TIMEOUT_ERROR'
}
```

#### 1.2 Error Context
```typescript
interface ErrorContext {
  module: string;
  operation: string;
  timestamp: Date;
  userId?: string;
  sessionId?: string;
  requestId?: string;
  correlationId?: string;
  metadata: Map<string, any>;
}
```

### 2. **Error Propagation Strategy**

#### 2.1 Module-Level Error Handling
```typescript
interface ModuleErrorHandler {
  handleError(error: Error, context: ErrorContext): Promise<ErrorResult>;
  isRetryable(error: Error): boolean;
  getErrorRecoveryStrategy(error: Error): ErrorRecoveryStrategy;
}
```

#### 2.2 Cross-Module Error Handling
- Error translation between modules
- Context preservation across boundaries
- Standardized error response format
- Error correlation and tracking

### 3. **Recovery Mechanisms**

#### 3.1 Retry Strategies
```typescript
interface RetryStrategy {
  shouldRetry(error: Error, attemptCount: number): boolean;
  getNextRetryDelay(attemptCount: number): number;
  getMaxRetryAttempts(): number;
}
```

#### 3.2 Circuit Breaker Integration
```typescript
interface CircuitBreakerIntegration {
  recordSuccess(): void;
  recordFailure(error: Error): void;
  getState(): CircuitBreakerState;
  executeWithCircuitBreaker<T>(operation: () => Promise<T>): Promise<T>;
}
```

## Scalability Integration Patterns

### 1. **Load Balancing Integration**

#### 1.1 Service Load Balancing
```typescript
interface LoadBalancer {
  selectServiceInstance(serviceName: string): Promise<ServiceInstance>;
  reportServiceHealth(instanceId: string, health: ServiceHealth): Promise<void>;
  getServiceInstances(serviceName: string): Promise<ServiceInstance[]>;
}
```

#### 1.2 Database Load Balancing
- Read/write splitting
- Connection pooling
- Query optimization
- Caching integration

### 2. **Caching Integration**

#### 2.1 Multi-Level Caching
```typescript
interface CacheHierarchy {
  getFromCache(key: string): Promise<any>;
  setInCache(key: string, value: any, ttl?: number): Promise<void>;
  invalidateCache(key: string): Promise<void>;
  getCacheStats(): Promise<CacheStatistics>;
}
```

#### 2.2 Cache Consistency
- Cache invalidation strategies
- Cache warming mechanisms
- Distributed cache synchronization
- Performance monitoring

### 3. **Asynchronous Processing Integration**

#### 3.1 Queue-Based Processing
```typescript
interface AsyncProcessor {
  enqueueTask(task: AsyncTask): Promise<TaskId>;
  processTask(taskId: TaskId): Promise<TaskResult>;
  getTaskStatus(taskId: TaskId): Promise<TaskStatus>;
  cancelTask(taskId: TaskId): Promise<void>;
}
```

#### 3.2 Batch Processing
- Batch formation strategies
- Batch processing pipelines
- Error handling in batches
- Result aggregation

## Integration Monitoring and Observability

### 1. **Integration Health Monitoring**

#### 1.1 Health Check Integration
```typescript
interface IntegrationHealthMonitor {
  checkModuleHealth(moduleName: string): Promise<HealthStatus>;
  checkExternalServiceHealth(serviceName: string): Promise<HealthStatus>;
  getOverallSystemHealth(): Promise<SystemHealth>;
}
```

#### 1.2 Performance Monitoring
- Response time tracking
- Throughput measurement
- Error rate monitoring
- Resource utilization tracking

### 2. **Integration Observability**

#### 2.1 Metrics Collection
```typescript
interface IntegrationMetricsCollector {
  recordRequestMetrics(endpoint: string, method: string, duration: number): void;
  recordErrorMetrics(errorType: string, endpoint: string): void;
  recordBusinessMetrics(metricName: string, value: number): void;
  getMetricsSummary(): Promise<MetricsSummary>;
}
```

#### 2.2 Distributed Tracing
- Request correlation across integrations
- Performance bottleneck identification
- Service dependency mapping
- End-to-end transaction tracking

## Security Integration

### 1. **Authentication Integration**

#### 1.1 Single Sign-On (SSO)
- Centralized authentication service
- Token-based session management
- Multi-factor authentication support
- Session timeout handling

#### 1.2 Authorization Integration
- Role-based access control (RBAC)
- Attribute-based access control (ABAC)
- Policy enforcement points
- Access logging and auditing

### 2. **Data Protection Integration**

#### 2.1 Encryption Integration
```typescript
interface DataEncryptionService {
  encrypt(data: any, encryptionKey: string): Promise<EncryptedData>;
  decrypt(encryptedData: EncryptedData, decryptionKey: string): Promise<any>;
  generateEncryptionKey(): Promise<string>;
  rotateEncryptionKey(oldKey: string, newKey: string): Promise<void>;
}
```

#### 2.2 Data Validation Integration
- Input sanitization
- Output validation
- Data integrity checks
- Schema validation

### 3. **Audit Integration**

#### 3.1 Audit Logging
```typescript
interface AuditLogger {
  logAccess(request: AccessRequest): Promise<void>;
  logDataChange(change: DataChange): Promise<void>;
  logSecurityEvent(event: SecurityEvent): Promise<void>;
  queryAuditLog(criteria: AuditQueryCriteria): Promise<AuditEntry[]>;
}
```

#### 3.2 Compliance Monitoring
- Regulatory compliance tracking
- Data retention policy enforcement
- Privacy protection measures
- Security incident response

## Deployment Integration

### 1. **Container Integration**

#### 1.1 Service Containerization
```typescript
interface ContainerOrchestrator {
  deployService(serviceName: string, image: string, config: ServiceConfig): Promise<DeploymentResult>;
  scaleService(serviceName: string, instanceCount: number): Promise<void>;
  updateService(serviceName: string, image: string): Promise<void>;
  getServiceStatus(serviceName: string): Promise<ServiceStatus>;
}
```

#### 1.2 Service Mesh Integration
- Service discovery
- Load balancing
- Security policies
- Observability

### 2. **Configuration Integration**

#### 2.1 Dynamic Configuration
```typescript
interface ConfigurationManager {
  getConfiguration(key: string): Promise<any>;
  updateConfiguration(key: string, value: any): Promise<void>;
  watchConfiguration(key: string, callback: ConfigurationChangeCallback): Subscription;
  validateConfiguration(config: any): Promise<ValidationResult>;
}
```

#### 2.2 Environment-Specific Configuration
- Development environment settings
- Staging environment configurations
- Production environment settings
- Feature flag management

## Integration Testing Framework

### 1. **Test Environment Setup**

#### 1.1 Environment Provisioning
```typescript
interface TestEnvironmentProvisioner {
  createTestEnvironment(config: TestEnvironmentConfig): Promise<TestEnvironment>;
  configureExternalServices(environment: TestEnvironment): Promise<void>;
  setupTestData(environment: TestEnvironment, dataSpec: TestDataSpec): Promise<void>;
  teardownTestEnvironment(environmentId: string): Promise<void>;
}
```

#### 1.2 Service Dependencies
- Real Google AI services
- Live MCP servers
- Actual database instances
- Real message queues

### 2. **Integration Test Execution**

#### 2.1 Test Orchestration
```typescript
interface IntegrationTestOrchestrator {
  executeTestSuite(suite: IntegrationTestSuite): Promise<TestSuiteResult>;
  executePerformanceTest(test: PerformanceTest): Promise<PerformanceTestResult>;
  executeLoadTest(test: LoadTest): Promise<LoadTestResult>;
  generateTestReport(results: TestResult[]): Promise<TestReport>;
}
```

#### 2.2 Test Data Management
- Live data generation
- Data isolation between tests
- Automatic cleanup procedures
- Data validation and verification

### 3. **Test Validation and Reporting**

#### 3.1 Result Validation
```typescript
interface TestResultValidator {
  validateTestResult(result: TestResult): Promise<ValidationResult>;
  compareWithBaseline(result: TestResult, baseline: Baseline): Promise<ComparisonResult>;
  generateValidationReport(results: TestResult[]): Promise<ValidationReport>;
}
```

#### 3.2 Performance Benchmarking
- Response time measurements
- Throughput calculations
- Resource utilization tracking
- Scalability validation

## Integration Patterns Summary

| Pattern | Use Case | Implementation |
|---------|----------|----------------|
| **Direct Call** | High-performance internal calls | Interface-based method calls |
| **HTTP/REST** | Service-to-service communication | RESTful API with OpenAPI spec |
| **Event-Driven** | Asynchronous processing | Event bus with pub/sub |
| **Message Queue** | Reliable ordered delivery | Queue-based message processing |
| **Streaming** | Continuous data flow | Reactive streams |
| **Circuit Breaker** | Failure isolation | Resilience patterns |
| **Load Balancer** | Service scaling | Intelligent routing |
| **Cache Hierarchy** | Performance optimization | Multi-level caching |

## Best Practices

### 1. **Interface Design**
- Keep interfaces minimal and focused
- Use clear naming conventions
- Include comprehensive documentation
- Version interfaces explicitly

### 2. **Error Handling**
- Handle errors at appropriate boundaries
- Provide meaningful error messages
- Implement retry mechanisms
- Use circuit breakers for external calls

### 3. **Data Consistency**
- Validate data at integration points
- Use transactions for related operations
- Implement idempotency where appropriate
- Maintain audit trails

### 4. **Performance Optimization**
- Use caching strategically
- Implement connection pooling
- Optimize data serialization
- Monitor performance metrics

### 5. **Security**
- Encrypt sensitive data in transit
- Validate all inputs
- Implement proper authentication
- Audit all access

---

**Next Steps**: Review this integration architecture specification and provide feedback on communication patterns, error handling strategies, or testing approaches before proceeding to configuration management architecture.