What is a core characteristic of the Modern API?

A core characteristic of a Modern API is that it is designed first using an API specification for rapid feedback. This approach emphasizes the importance of planning and designing the API structure before implementation, which allows for early validation of requirements and ease of communication among stakeholders. By using an API specification, developers can create clear, documented interfaces that facilitate collaboration, reduce misunderstandings, and ensure that the API meets the needs of its consumers.

This design-first approach also aligns well with agile methodologies, as it enables iterative development and the incorporation of user feedback at various stages. Additionally, it encourages the use of tools and platforms that support automatic generation of documentation and client SDKs, further enhancing the API development lifecycle and user experience.

Other traits like API production speed or adherence to specific architectural styles like REST may be important, but they do not capture the essence of what makes an API "modern." The focus on specification and early feedback distinguishes this approach as foundational for building effective, user-centric APIs.