Hexagonal Architecture

Hexagonal Architecture, also known as Ports and Adapters, emphasizes separation between core behavior and external systems.

This page shows how ForgingBlocks concepts can be projected onto a hexagonal arrangement.

Important

ForgingBlocks does not enforce Hexagonal Architecture.
This page presents it as an interpretation of responsibilities defined in the Reference section.

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Quick summary

Hexagonal Architecture (Ports and Adapters) emphasizes separation between core behavior and external systems. This page shows how ForgingBlocks concepts can be projected onto this arrangement — not enforced.

Mapping:
- Core — Domain (business rules) + Application (Use Cases, Handlers)
- Inbound Ports — Define how behavior is triggered (UseCase, MessageHandler)
- Outbound Ports — Define required external capabilities (RepositoryPort, MessageBusPort, UnitOfWorkPort)
- Adapters — Implement ports (Infrastructure: SQL repos, message brokers, HTTP clients)
- Dependencies point toward the core

Fits when: external systems change frequently; testing without infrastructure matters; inbound/outbound isolation needed.

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Conceptual mapping

• The core contains Domain and Application logic.
• Inbound ports define how behavior is triggered.
• Outbound ports define required external capabilities.
• Adapters implement those ports.
• Dependencies point toward the core.

The diagram below shows a canonical hexagonal view from the literature, independent of ForgingBlocks.

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title: Hexagonal Architecture
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graph LR
    InboundAdapters[Inbound Adapters<br/>HTTP, CLI, Events] -->|execute/handle| ApplicationCore[Application Core<br/>Use Cases & Handlers]
    ApplicationCore -->|dispatch/persist/notify| OutboundAdapters[Outbound Adapters<br/>Repositories, Message Bus]

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When this style fits

• External systems change frequently.
• Testing without infrastructure is important.
• Inbound and outbound interactions must be isolated.