python-seedwork

DDD and Hexagonal Architecture building blocks for Python.

Goals

• Unify design patterns. Provide a shared vocabulary — entities, aggregates, value objects, domain events, CQRS buses — so every bounded context starts from the same foundation.
• Keep domain logic pure. The domain layer has zero framework or infrastructure imports. Business rules live in the domain; everything else lives in infrastructure.
• Clear layer boundaries. Protocols define contracts; implementations satisfy them structurally. The dependency direction is enforced: domain ← application ← infrastructure.

Components

Layer	Package	Components
Domain	seedwork.domain	Entity, AggregateRoot, ValueObject, DomainEvent, DomainEventRecord, DomainError, Repository, UnitOfWork
Application	seedwork.application	Command, Query[TResult], CommandHandler, QueryHandler, CommandBus, QueryBus, Result, DomainEventBusPublisher, DomainEventBusSubscriber, DomainEventBus, DomainEventHandler, BaseIntegrationEvent[TPayload], IntegrationEvent[TPayload], IntegrationEventPublisher, IntegrationEventHandler, BackgroundTask[TPayload], TaskScheduler
Infrastructure	seedwork.infrastructure	RegistryCommandBus, RegistryQueryBus, TransactionalCommandBus, DomainEventCoordinatorCommandBus, CommandBusBuilder, QueryBusBuilder, DeferredDomainEventBus, DomainEventPublishingRepository, InMemoryRepository

All components are also re-exported from the top-level seedwork package.

Installation

pip install python-seedwork

Requires Python 3.12+. Ships a py.typed marker (PEP 561) — mypy and pyright pick up the inline types automatically.

Documentation

Comprehensive guides are available in the docs/ directory:

• Getting Started
• Component Reference
• Coding Standards

A complete Bank Account example demonstrates all patterns end-to-end.

Requirements

Python 3.12+, uv

Built With

• Python 3.12+
• uv — dependency management and packaging
• Ruff — linting and formatting
• Pyright — strict static type checking
• pytest — testing with coverage gate
• python-semantic-release — automated versioning and changelog

Development

git clone https://github.com/aseguragonzalez/python-seedwork.git
cd python-seedwork
make install

Command	Description
make check	Lint, typecheck, and tests (what CI runs)
make lint	Run ruff linter
make format	Format and auto-fix with ruff
make typecheck	Run pyright
make test	Run tests with coverage (90% gate)
make test-no-cov	Run tests without coverage
make clean	Remove build artifacts and caches

Contributing

This project follows the Conventional Commits specification. The commit-msg pre-commit hook enforces the format; python-semantic-release derives versions and the changelog from commit prefixes automatically.

References

This package draws on the following literature and on the experience of building solid, scalable, and maintainable systems in different stacks (PHP, C#, Python, TypeScript).

• Eric Evans, Domain-Driven Design: Tackling Complexity in the Heart of Software 1
• Vaughn Vernon, Implementing Domain-Driven Design 2
• Robert C. Martin, Clean Architecture: A Craftsman's Guide to Software Structure and Design 3
• .NET Microservices: Architecture for Containerized .NET Applications 4
• Architecture Patterns with Python, Harry Percival & Bob Gregory 5

License

MIT