FastAPI DDD Template

A clean, production-ready Domain-Driven Design + Hexagonal Architecture template for FastAPI.

Built with modern best practices (2025):

• FastAPI (async)
• SQLAlchemy 2.0 + async session
• Pure DDD: Entities, Value Objects, Domain Events, Aggregates
• Hexagonal / Clean Architecture
• Unit of Work + Repository pattern
• Dependency inversion via Protocols
• Argon2id password hashing
• Explicit, type-safe, and fully testable structure

Designed to serve as:

• A learning reference for advanced backend architecture
• A solid foundation for microservices and long-lived projects
• A template you can clone and extend confidently

Project structure

app/
├── domain/          # Pure business logic (no framework imports)
├── application/     # Use cases, commands, handlers
├── infrastructure/  # Database, external adapters, implementations
└── presentation/    # FastAPI routers, DTOs, dependencies

Features

• 100% async
• Zero hidden magic
• Easy to test (no database in unit tests)
• Ready for gRPC, CQRS, Event Sourcing, Docker, etc.
• Follows patterns used in high-scale production systems

Status

Actively maintained · Work in progress · Continuously improved

Feel free to fork, study, and use as your personal architecture playground.

Contributions and stars are highly appreciated!

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Made with passion for clean, maintainable, and scalable code.