MULE ESB provides an API layer that offers a decoupled interface for interacting with applications in a common, language-agnostic way. An API layer is commonly used to connect to legacy applications that lack REST APIs or to publish partner-facing APIs. The Anypoint Platform enables API-led connectivity by helping users build, manage, and secure APIs from a single platform. It includes an API gateway for connecting to backends, an API manager for user management and monitoring, an API contract manager for access control, and an API policy manager for security policies.