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Why MBC CQRS Serverless?

Building enterprise-grade serverless applications on AWS is hard. You need to handle:

• Event sourcing and CQRS patterns
• Multi-tenancy and data isolation
• DynamoDB to RDS synchronization
• Sequence number generation
• Async task processing
• ...and much more

MBC CQRS Serverless provides all of this out of the box, so you can focus on your business logic.

Key Benefits

Feature	What You Get
Zero to API in 5 minutes	CLI generates complete project structure with best practices
Built-in Multi-tenancy	Data isolation, tenant settings, and RBAC out of the box
Event Sourcing	Full audit trail with DynamoDB Streams and automatic RDS sync
Local Development	Complete offline mode with Docker - no AWS costs during development
Production Ready	Battle-tested in enterprise SaaS applications

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Quick Start

# Install CLI
npm install -g @mbc-cqrs-serverless/cli

# Create new project
mbc new my-saas-app

# Start development
cd my-saas-app
npm install
npm run build            # Build the project
npm run offline:docker   # Start local AWS services
npm run migrate          # Run database migrations
npm run offline:sls      # Start API server

That's it! Your API is running at http://localhost:4000

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See It in Action

Create a CRUD endpoint in 30 lines:

// todo.controller.ts
@Controller('api/todo')
export class TodoController {
  constructor(
    private readonly commandService: CommandService,
    private readonly dataService: DataService,
  ) {}

  @Post()
  async create(@Body() dto: CreateTodoDto, @IInvoke() invokeContext: IInvoke) {
    const command = new TodoCommandDto({
      pk: dto.pk,
      sk: dto.sk,
      tenantCode: invokeContext.tenantCode,
      name: dto.name,
      attributes: { description: dto.description },
    });
    return this.commandService.publishSync(command, { invokeContext });
  }

  @Get(':pk/:sk')
  async findOne(@Param('pk') pk: string, @Param('sk') sk: string) {
    return this.dataService.getItem({ pk, sk });
  }
}

What happens automatically:

• Command is validated and persisted to DynamoDB
• Event is emitted via DynamoDB Streams
• Data is synced to RDS for complex queries
• Full audit trail is maintained
• Multi-tenant isolation is enforced

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Architecture

┌─────────────────────────────────────────────────────────────────────┐
│                         Your Application                             │
├─────────────────────────────────────────────────────────────────────┤
│                                                                      │
│   Client Request                                                     │
│        │                                                             │
│        ▼                                                             │
│   ┌─────────┐    ┌─────────┐    ┌──────────────┐                    │
│   │   API   │───▶│ Service │───▶│ CommandService│                    │
│   │ Gateway │    │  Layer  │    │   (Write)    │                    │
│   └─────────┘    └─────────┘    └──────────────┘                    │
│                       │                │                             │
│                       │                ▼                             │
│                       │         ┌──────────────┐                    │
│                       │         │  DynamoDB    │──── Stream ───┐    │
│                       │         │  (Commands)  │               │    │
│                       │         └──────────────┘               ▼    │
│                       │                              ┌──────────────┐│
│                       ▼                              │Step Functions││
│                ┌──────────────┐                      └──────────────┘│
│                │ DataService  │                              │       │
│                │   (Read)     │                              ▼       │
│                └──────────────┘                      ┌──────────────┐│
│                       │                              │  DynamoDB    ││
│                       ▼                              │   (Data)     ││
│                ┌──────────────┐                      └──────────────┘│
│                │     RDS      │◀──── Sync ───────────────────┘       │
│                │   (Query)    │                                      │
│                └──────────────┘                                      │
│                                                                      │
└─────────────────────────────────────────────────────────────────────┘

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Packages

Package	Description	Version
@mbc-cqrs-serverless/core	Core CQRS framework with AWS integrations
@mbc-cqrs-serverless/cli	CLI tool for project scaffolding
@mbc-cqrs-serverless/tenant	Multi-tenancy support
@mbc-cqrs-serverless/master	Master data and hierarchical settings
@mbc-cqrs-serverless/sequence	Sequence number generation with rotation
@mbc-cqrs-serverless/task	Async task processing and queue management
@mbc-cqrs-serverless/import	Data import with CSV and REST support
@mbc-cqrs-serverless/ui-setting	UI configuration management

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Features

Core Framework

• CQRS Pattern - Clean separation of commands (writes) and queries (reads)
• Event Sourcing - Complete audit trail with immutable event log
• Optimistic Locking - Automatic conflict resolution for concurrent updates

AWS Integration

• Lambda - Serverless compute with automatic scaling
• DynamoDB - Event store and data persistence
• RDS/Aurora - Complex queries with Prisma ORM
• Cognito - Authentication and authorization
• Step Functions - Workflow orchestration
• SNS/SQS - Event-driven messaging

Enterprise Features

• Multi-tenancy - Built-in tenant isolation and settings hierarchy
• Sequence Generation - Auto-incrementing IDs with date rotation
• Master Data - Centralized configuration management
• Async Tasks - Background job processing with retries

Developer Experience

• Full TypeScript - Type-safe development with excellent IDE support
• NestJS Foundation - Familiar patterns and dependency injection
• Local Development - Complete offline mode with Docker
• CLI Tools - Project scaffolding and code generation

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Examples

Check out our sample repository for complete working examples:

Example	Description
step-01-setup	Environment setup
step-02-create	Create operations with CommandService
step-03-rds-sync	DynamoDB to RDS synchronization
step-04-read	Read operations with DataService
step-05-search	Search with Prisma/RDS
step-06-update-delete	Update and soft delete
step-07-sequence	Sequence number generation
complete/basic	Full CRUD implementation

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Documentation

Visit our documentation site for:

• Getting Started Guide
• Build a Todo App Tutorial
• API Reference
• Architecture Guide

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Installation

Latest Stable Release

npm install -g @mbc-cqrs-serverless/cli

Beta Release (Latest Features)

npm install -g @mbc-cqrs-serverless/cli@beta

Specific Version

npm install -g @mbc-cqrs-serverless/cli@1.0.17

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Contributing

We welcome contributions! Please see our Contributing Guide for details.

# Clone the repository
git clone https://github.com/mbc-net/mbc-cqrs-serverless.git

# Install dependencies
npm install

# Build all packages
npm run build

# Run tests
npm test

Development Workflow

1. Fork the repository
2. Create a feature branch from develop
3. Make your changes with tests
4. Submit a pull request

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Community

• GitHub Issues - Bug reports and feature requests
• GitHub Discussions - Questions and discussions
• Changelog - Release notes

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License

Copyright © 2024-2025, Murakami Business Consulting, Inc.

This project is licensed under the MIT License.

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