<!-- TIER:1 -- Building APIs An API is a RESTful endpoint that exposes integration logic for external consumption. External systems call the API over HTTP; the API processes the request through lookups and imports, then returns a structured response. Concerns when building an API: - Mode selection -- builder (visual configuration) vs script (full JavaScript control) - Request definition -- HTTP method, URI path, parameters, body schema, request transformation - Processing pipeline -- routers and page processors (lookups + imports) that execute business logic - Response routing -- directing pr…