Component Model

Component Model describes an architectural approach in which software is composed from independent, reusable components that expose well-defined interfaces and hide their internals. Instead of one monolithic program, a system becomes an assembly of parts that can be developed, versioned, tested, and replaced on their own. The idea underpins everything from classic component frameworks to the modern WebAssembly Component Model.

• Well-defined interfaces - Each component publishes a contract, so consumers depend on the interface rather than the implementation.
• Encapsulation - Internal state and logic stay private, keeping components loosely coupled and independently changeable.
• Composability - Components combine into larger systems, and one can be swapped for another that honors the same contract.
• Independent lifecycle - Parts can be built, versioned, and deployed separately instead of moving as a single unit.

The component mindset maps almost directly onto how modern APIs are designed. An API is a contract over an encapsulated capability, and API-first teams treat each service as a swappable component behind a stable interface — the same discipline that lets OpenAPI-described services be composed, mocked, and governed independently. As agents begin assembling capabilities on the fly, clean component boundaries and honest interface contracts are what make that composition safe rather than brittle.