Enterprise Integration Patterns

Enterprise Integration Patterns is a catalog of reusable, messaging-based design patterns for connecting applications across an enterprise, cataloged by Gregor Hohpe and Bobby Woolf in their 2003 book of the same name. Rather than a single specification, it is a shared vocabulary — message channels, routers, translators, endpoints — for the recurring problems that show up whenever systems have to exchange data reliably and asynchronously.

• A pattern language, not a product - Sixty-five named patterns that describe the moving parts of asynchronous integration in vendor-neutral terms.
• Messaging as the backbone - Channels, messages, and endpoints frame integration as loosely-coupled systems passing messages rather than tightly-coupled calls.
• Composable building blocks - Content-based routers, message translators, aggregators, and splitters combine into pipelines that solve real integration flows.
• A durable common language - The icons and terminology are baked into integration frameworks like Apache Camel, Spring Integration, and MuleSoft.

In API operations, Enterprise Integration Patterns is the conceptual layer beneath much of what happens once APIs stop being called one at a time and start being wired together. The patterns describe how events move through queues, how payloads get transformed between systems, and how integrations stay resilient under failure — the same concerns that resurface in Event-driven Architecture and modern message brokers. As integration shifts toward agents orchestrating many APIs at once, this decades-old vocabulary remains the clearest way to reason about routing, transformation, and reliability.