An API designer agent defines, documents, and enforces the shape of your service interfaces before implementation begins. It writes OpenAPI specs, reviews proposed API changes for consistency, and flags breaking changes that would require a version bump or a migration period.
API design decisions are hard to reverse once consumers exist. A role-specific prompt encodes your API conventions: how resources are named, how errors are structured, what pagination contract you use, and how versioning is managed. Without this context, a generalist agent produces internally consistent but externally incompatible changes.