v3-core-implementation

name	V3 Core Implementation
description	Core module implementation for Codex-flow v3. Implements DDD domains, clean architecture patterns, dependency injection, and modular TypeScript codebase with comprehensive testing.

V3 Core Implementation

What This Skill Does

Implements the core TypeScript modules for Codex-flow v3 following Domain-Driven Design principles, clean architecture patterns, and modern TypeScript best practices with comprehensive test coverage.

Quick Start

# Initialize core implementation
Task("Core foundation", "Set up DDD domain structure and base classes", "core-implementer")

# Domain implementation (parallel)
Task("Task domain", "Implement task management domain with entities and services", "core-implementer")
Task("Session domain", "Implement session management domain", "core-implementer")
Task("Health domain", "Implement health monitoring domain", "core-implementer")

Core Implementation Architecture

Domain Structure

src/
├── core/
│   ├── kernel/                     # Microkernel pattern
│   │   ├── Codex-flow-kernel.ts
│   │   ├── domain-registry.ts
│   │   └── plugin-loader.ts
│   │
│   ├── domains/                    # DDD Bounded Contexts
│   │   ├── task-management/
│   │   │   ├── entities/
│   │   │   ├── value-objects/
│   │   │   ├── services/
│   │   │   ├── repositories/
│   │   │   └── events/
│   │   │
│   │   ├── session-management/
│   │   ├── health-monitoring/
│   │   ├── lifecycle-management/
│   │   └── event-coordination/
│   │
│   ├── shared/                     # Shared kernel
│   │   ├── domain/
│   │   │   ├── entity.ts
│   │   │   ├── value-object.ts
│   │   │   ├── domain-event.ts
│   │   │   └── aggregate-root.ts
│   │   │
│   │   ├── infrastructure/
│   │   │   ├── event-bus.ts
│   │   │   ├── dependency-container.ts
│   │   │   └── logger.ts
│   │   │
│   │   └── types/
│   │       ├── common.ts
│   │       ├── errors.ts
│   │       └── interfaces.ts
│   │
│   └── application/                # Application services
│       ├── use-cases/
│       ├── commands/
│       ├── queries/
│       └── handlers/

Base Domain Classes

Entity Base Class

// src/core/shared/domain/entity.ts
export abstract class Entity<T> {
  protected readonly _id: T;
  private _domainEvents: DomainEvent[] = [];

  constructor(id: T) {
    this._id = id;
  }

  get id(): T {
    return this._id;
  }

  public equals(object?: Entity<T>): boolean {
    if (object == null || object == undefined) {
      return false;
    }

    if (this === object) {
      return true;
    }

    if (!(object instanceof Entity)) {
      return false;
    }

    return this._id === object._id;
  }

  protected addDomainEvent(domainEvent: DomainEvent): void {
    this._domainEvents.push(domainEvent);
  }

  public getUncommittedEvents(): DomainEvent[] {
    return this._domainEvents;
  }

  public markEventsAsCommitted(): void {
    this._domainEvents = [];
  }
}

Value Object Base Class

// src/core/shared/domain/value-object.ts
export abstract class ValueObject<T> {
  protected readonly props: T;

  constructor(props: T) {
    this.props = Object.freeze(props);
  }

  public equals(object?: ValueObject<T>): boolean {
    if (object == null || object == undefined) {
      return false;
    }

    if (this === object) {
      return true;
    }

    return JSON.stringify(this.props) === JSON.stringify(object.props);
  }

  get value(): T {
    return this.props;
  }
}

Aggregate Root

// src/core/shared/domain/aggregate-root.ts
export abstract class AggregateRoot<T> extends Entity<T> {
  private _version: number = 0;

  get version(): number {
    return this._version;
  }

  protected incrementVersion(): void {
    this._version++;
  }

  public applyEvent(event: DomainEvent): void {
    this.addDomainEvent(event);
    this.incrementVersion();
  }
}

Task Management Domain Implementation

Task Entity

// src/core/domains/task-management/entities/task.entity.ts
import { AggregateRoot } from '../../../shared/domain/aggregate-root';
import { TaskId } from '../value-objects/task-id.vo';
import { TaskStatus } from '../value-objects/task-status.vo';
import { Priority } from '../value-objects/priority.vo';
import { TaskAssignedEvent } from '../events/task-assigned.event';

interface TaskProps {
  id: TaskId;
  description: string;
  priority: Priority;
  status: TaskStatus;
  assignedAgentId?: string;
  createdAt: Date;
  updatedAt: Date;
}

export class Task extends AggregateRoot<TaskId> {
  private props: TaskProps;

  private constructor(props: TaskProps) {
    super(props.id);
    this.props = props;
  }

  static create(description: string, priority: Priority): Task {
    const task = new Task({
      id: TaskId.create(),
      description,
      priority,
      status: TaskStatus.pending(),
      createdAt: new Date(),
      updatedAt: new Date()
    });

    return task;
  }

  static reconstitute(props: TaskProps): Task {
    return new Task(props);
  }

  public assignTo(agentId: string): void {
    if (this.props.status.equals(TaskStatus.completed())) {
      throw new Error('Cannot assign completed task');
    }

    this.props.assignedAgentId = agentId;
    this.props.status = TaskStatus.assigned();
    this.props.updatedAt = new Date();

    this.applyEvent(new TaskAssignedEvent(
      this.id.value,
      agentId,
      this.props.priority
    ));
  }

  public complete(result: TaskResult): void {
    if (!this.props.assignedAgentId) {
      throw new Error('Cannot complete unassigned task');
    }

    this.props.status = TaskStatus.completed();
    this.props.updatedAt = new Date();

    this.applyEvent(new TaskCompletedEvent(
      this.id.value,
      result,
      this.calculateDuration()
    ));
  }

  // Getters
  get description(): string { return this.props.description; }
  get priority(): Priority { return this.props.priority; }
  get status(): TaskStatus { return this.props.status; }
  get assignedAgentId(): string | undefined { return this.props.assignedAgentId; }
  get createdAt(): Date { return this.props.createdAt; }
  get updatedAt(): Date { return this.props.updatedAt; }

  private calculateDuration(): number {
    return this.props.updatedAt.getTime() - this.props.createdAt.getTime();
  }
}

Task Value Objects

// src/core/domains/task-management/value-objects/task-id.vo.ts
export class TaskId extends ValueObject<string> {
  private constructor(value: string) {
    super({ value });
  }

  static create(): TaskId {
    return new TaskId(crypto.randomUUID());
  }

  static fromString(id: string): TaskId {
    if (!id || id.length === 0) {
      throw new Error('TaskId cannot be empty');
    }
    return new TaskId(id);
  }

  get value(): string {
    return this.props.value;
  }
}

// src/core/domains/task-management/value-objects/task-status.vo.ts
type TaskStatusType = 'pending' | 'assigned' | 'in_progress' | 'completed' | 'failed';

export class TaskStatus extends ValueObject<TaskStatusType> {
  private constructor(status: TaskStatusType) {
    super({ value: status });
  }

  static pending(): TaskStatus { return new TaskStatus('pending'); }
  static assigned(): TaskStatus { return new TaskStatus('assigned'); }
  static inProgress(): TaskStatus { return new TaskStatus('in_progress'); }
  static completed(): TaskStatus { return new TaskStatus('completed'); }
  static failed(): TaskStatus { return new TaskStatus('failed'); }

  get value(): TaskStatusType {
    return this.props.value;
  }

  public isPending(): boolean { return this.value === 'pending'; }
  public isAssigned(): boolean { return this.value === 'assigned'; }
  public isInProgress(): boolean { return this.value === 'in_progress'; }
  public isCompleted(): boolean { return this.value === 'completed'; }
  public isFailed(): boolean { return this.value === 'failed'; }
}

// src/core/domains/task-management/value-objects/priority.vo.ts
type PriorityLevel = 'low' | 'medium' | 'high' | 'critical';

export class Priority extends ValueObject<PriorityLevel> {
  private constructor(level: PriorityLevel) {
    super({ value: level });
  }

  static low(): Priority { return new Priority('low'); }
  static medium(): Priority { return new Priority('medium'); }
  static high(): Priority { return new Priority('high'); }
  static critical(): Priority { return new Priority('critical'); }

  get value(): PriorityLevel {
    return this.props.value;
  }

  public getNumericValue(): number {
    const priorities = { low: 1, medium: 2, high: 3, critical: 4 };
    return priorities[this.value];
  }
}

Domain Services

Task Scheduling Service

// src/core/domains/task-management/services/task-scheduling.service.ts
import { Injectable } from '../../../shared/infrastructure/dependency-container';
import { Task } from '../entities/task.entity';
import { Priority } from '../value-objects/priority.vo';

@Injectable()
export class TaskSchedulingService {
  public prioritizeTasks(tasks: Task[]): Task[] {
    return tasks.sort((a, b) =>
      b.priority.getNumericValue() - a.priority.getNumericValue()
    );
  }

  public canSchedule(task: Task, agentCapacity: number): boolean {
    if (agentCapacity <= 0) return false;

    // Critical tasks always schedulable
    if (task.priority.equals(Priority.critical())) return true;

    // Other logic based on capacity
    return true;
  }

  public calculateEstimatedDuration(task: Task): number {
    // Simple heuristic - would use ML in real implementation
    const baseTime = 300000; // 5 minutes
    const priorityMultiplier = {
      low: 0.5,
      medium: 1.0,
      high: 1.5,
      critical: 2.0
    };

    return baseTime * priorityMultiplier[task.priority.value];
  }
}

Repository Interfaces & Implementations

Task Repository Interface

// src/core/domains/task-management/repositories/task.repository.ts
export interface ITaskRepository {
  save(task: Task): Promise<void>;
  findById(id: TaskId): Promise<Task | null>;
  findByAgentId(agentId: string): Promise<Task[]>;
  findByStatus(status: TaskStatus): Promise<Task[]>;
  findPendingTasks(): Promise<Task[]>;
  delete(id: TaskId): Promise<void>;
}

SQLite Implementation

// src/core/domains/task-management/repositories/sqlite-task.repository.ts
@Injectable()
export class SqliteTaskRepository implements ITaskRepository {
  constructor(
    @Inject('Database') private db: Database,
    @Inject('Logger') private logger: ILogger
  ) {}

  async save(task: Task): Promise<void> {
    const sql = `
      INSERT OR REPLACE INTO tasks (
        id, description, priority, status, assigned_agent_id, created_at, updated_at
      ) VALUES (?, ?, ?, ?, ?, ?, ?)
    `;

    await this.db.run(sql, [
      task.id.value,
      task.description,
      task.priority.value,
      task.status.value,
      task.assignedAgentId,
      task.createdAt.toISOString(),
      task.updatedAt.toISOString()
    ]);

    this.logger.debug(`Task saved: ${task.id.value}`);
  }

  async findById(id: TaskId): Promise<Task | null> {
    const sql = 'SELECT * FROM tasks WHERE id = ?';
    const row = await this.db.get(sql, [id.value]);

    return row ? this.mapRowToTask(row) : null;
  }

  async findPendingTasks(): Promise<Task[]> {
    const sql = 'SELECT * FROM tasks WHERE status = ? ORDER BY priority DESC, created_at ASC';
    const rows = await this.db.all(sql, ['pending']);

    return rows.map(row => this.mapRowToTask(row));
  }

  private mapRowToTask(row: any): Task {
    return Task.reconstitute({
      id: TaskId.fromString(row.id),
      description: row.description,
      priority: Priority.fromString(row.priority),
      status: TaskStatus.fromString(row.status),
      assignedAgentId: row.assigned_agent_id,
      createdAt: new Date(row.created_at),
      updatedAt: new Date(row.updated_at)
    });
  }
}

Application Layer

Use Case Implementation

// src/core/application/use-cases/assign-task.use-case.ts
@Injectable()
export class AssignTaskUseCase {
  constructor(
    @Inject('TaskRepository') private taskRepository: ITaskRepository,
    @Inject('AgentRepository') private agentRepository: IAgentRepository,
    @Inject('DomainEventBus') private eventBus: DomainEventBus,
    @Inject('Logger') private logger: ILogger
  ) {}

  async execute(command: AssignTaskCommand): Promise<AssignTaskResult> {
    try {
      // 1. Validate command
      await this.validateCommand(command);

      // 2. Load aggregates
      const task = await this.taskRepository.findById(command.taskId);
      if (!task) {
        throw new TaskNotFoundError(command.taskId);
      }

      const agent = await this.agentRepository.findById(command.agentId);
      if (!agent) {
        throw new AgentNotFoundError(command.agentId);
      }

      // 3. Business logic
      if (!agent.canAcceptTask(task)) {
        throw new AgentCannotAcceptTaskError(command.agentId, command.taskId);
      }

      task.assignTo(command.agentId);
      agent.acceptTask(task.id);

      // 4. Persist changes
      await Promise.all([
        this.taskRepository.save(task),
        this.agentRepository.save(agent)
      ]);

      // 5. Publish domain events
      const events = [
        ...task.getUncommittedEvents(),
        ...agent.getUncommittedEvents()
      ];

      for (const event of events) {
        await this.eventBus.publish(event);
      }

      task.markEventsAsCommitted();
      agent.markEventsAsCommitted();

      // 6. Return result
      this.logger.info(`Task ${command.taskId.value} assigned to agent ${command.agentId}`);

      return AssignTaskResult.success({
        taskId: task.id,
        agentId: command.agentId,
        assignedAt: new Date()
      });

    } catch (error) {
      this.logger.error(`Failed to assign task ${command.taskId.value}:`, error);
      return AssignTaskResult.failure(error);
    }
  }

  private async validateCommand(command: AssignTaskCommand): Promise<void> {
    if (!command.taskId) {
      throw new ValidationError('Task ID is required');
    }
    if (!command.agentId) {
      throw new ValidationError('Agent ID is required');
    }
  }
}

Dependency Injection Setup

Container Configuration

// src/core/shared/infrastructure/dependency-container.ts
import { Container } from 'inversify';
import { TYPES } from './types';

export class DependencyContainer {
  private container: Container;

  constructor() {
    this.container = new Container();
    this.setupBindings();
  }

  private setupBindings(): void {
    // Repositories
    this.container.bind<ITaskRepository>(TYPES.TaskRepository)
      .to(SqliteTaskRepository)
      .inSingletonScope();

    this.container.bind<IAgentRepository>(TYPES.AgentRepository)
      .to(SqliteAgentRepository)
      .inSingletonScope();

    // Services
    this.container.bind<TaskSchedulingService>(TYPES.TaskSchedulingService)
      .to(TaskSchedulingService)
      .inSingletonScope();

    // Use Cases
    this.container.bind<AssignTaskUseCase>(TYPES.AssignTaskUseCase)
      .to(AssignTaskUseCase)
      .inSingletonScope();

    // Infrastructure
    this.container.bind<ILogger>(TYPES.Logger)
      .to(ConsoleLogger)
      .inSingletonScope();

    this.container.bind<DomainEventBus>(TYPES.DomainEventBus)
      .to(InMemoryDomainEventBus)
      .inSingletonScope();
  }

  get<T>(serviceIdentifier: symbol): T {
    return this.container.get<T>(serviceIdentifier);
  }

  bind<T>(serviceIdentifier: symbol): BindingToSyntax<T> {
    return this.container.bind<T>(serviceIdentifier);
  }
}

Modern TypeScript Configuration

Strict TypeScript Setup

// tsconfig.json
{
  "compilerOptions": {
    "target": "ES2022",
    "lib": ["ES2022"],
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "declaration": true,
    "outDir": "./dist",
    "strict": true,
    "exactOptionalPropertyTypes": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    "noUncheckedIndexedAccess": true,
    "noImplicitOverride": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "resolveJsonModule": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "baseUrl": ".",
    "paths": {
      "@/*": ["src/*"],
      "@core/*": ["src/core/*"],
      "@shared/*": ["src/core/shared/*"],
      "@domains/*": ["src/core/domains/*"]
    }
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "dist", "**/*.test.ts", "**/*.spec.ts"]
}

Testing Implementation

Domain Unit Tests

// src/core/domains/task-management/__tests__/entities/task.entity.test.ts
describe('Task Entity', () => {
  let task: Task;

  beforeEach(() => {
    task = Task.create('Test task', Priority.medium());
  });

  describe('creation', () => {
    it('should create task with pending status', () => {
      expect(task.status.isPending()).toBe(true);
      expect(task.description).toBe('Test task');
      expect(task.priority.equals(Priority.medium())).toBe(true);
    });

    it('should generate unique ID', () => {
      const task1 = Task.create('Task 1', Priority.low());
      const task2 = Task.create('Task 2', Priority.low());

      expect(task1.id.equals(task2.id)).toBe(false);
    });
  });

  describe('assignment', () => {
    it('should assign to agent and change status', () => {
      const agentId = 'agent-123';

      task.assignTo(agentId);

      expect(task.assignedAgentId).toBe(agentId);
      expect(task.status.isAssigned()).toBe(true);
    });

    it('should emit TaskAssignedEvent when assigned', () => {
      const agentId = 'agent-123';

      task.assignTo(agentId);

      const events = task.getUncommittedEvents();
      expect(events).toHaveLength(1);
      expect(events[0]).toBeInstanceOf(TaskAssignedEvent);
    });

    it('should not allow assignment of completed task', () => {
      task.assignTo('agent-123');
      task.complete(TaskResult.success('done'));

      expect(() => task.assignTo('agent-456'))
        .toThrow('Cannot assign completed task');
    });
  });
});

Integration Tests

// src/core/domains/task-management/__tests__/integration/task-repository.integration.test.ts
describe('TaskRepository Integration', () => {
  let repository: SqliteTaskRepository;
  let db: Database;

  beforeEach(async () => {
    db = new Database(':memory:');
    await setupTasksTable(db);
    repository = new SqliteTaskRepository(db, new ConsoleLogger());
  });

  afterEach(async () => {
    await db.close();
  });

  it('should save and retrieve task', async () => {
    const task = Task.create('Test task', Priority.high());

    await repository.save(task);
    const retrieved = await repository.findById(task.id);

    expect(retrieved).toBeDefined();
    expect(retrieved!.id.equals(task.id)).toBe(true);
    expect(retrieved!.description).toBe('Test task');
    expect(retrieved!.priority.equals(Priority.high())).toBe(true);
  });

  it('should find pending tasks ordered by priority', async () => {
    const lowTask = Task.create('Low priority', Priority.low());
    const highTask = Task.create('High priority', Priority.high());

    await repository.save(lowTask);
    await repository.save(highTask);

    const pending = await repository.findPendingTasks();

    expect(pending).toHaveLength(2);
    expect(pending[0].id.equals(highTask.id)).toBe(true); // High priority first
    expect(pending[1].id.equals(lowTask.id)).toBe(true);
  });
});

Performance Optimizations

Entity Caching

// src/core/shared/infrastructure/entity-cache.ts
@Injectable()
export class EntityCache<T extends Entity<any>> {
  private cache = new Map<string, { entity: T; timestamp: number }>();
  private readonly ttl: number = 300000; // 5 minutes

  set(id: string, entity: T): void {
    this.cache.set(id, { entity, timestamp: Date.now() });
  }

  get(id: string): T | null {
    const cached = this.cache.get(id);
    if (!cached) return null;

    // Check TTL
    if (Date.now() - cached.timestamp > this.ttl) {
      this.cache.delete(id);
      return null;
    }

    return cached.entity;
  }

  invalidate(id: string): void {
    this.cache.delete(id);
  }

  clear(): void {
    this.cache.clear();
  }
}

Success Metrics

• Domain Isolation: 100% clean dependency boundaries
• Test Coverage: >90% unit test coverage for domain logic
• Type Safety: Strict TypeScript compilation with zero any types
• Performance: <50ms average use case execution time
• Memory Efficiency: <100MB heap usage for core domains
• Plugin Architecture: Modular domain loading capability

Related V3 Skills

• v3-ddd-architecture - DDD architectural design
• v3-mcp-optimization - MCP server integration
• v3-memory-unification - AgentDB repository integration
• v3-swarm-coordination - Swarm domain implementation

Usage Examples

Complete Core Implementation

# Full core module implementation
Task("Core implementation",
     "Implement all core domains with DDD patterns and comprehensive testing",
     "core-implementer")

Domain-Specific Implementation

# Single domain implementation
Task("Task domain implementation",
     "Implement task management domain with entities, services, and repositories",
     "core-implementer")