What is a best practice for exposing API endpoints to manage default addresses?

What is a best practice for exposing API endpoints to manage default addresses?

• A. Expose endpoints that require explicit defaults every time.
• B. Provide no endpoints to manage defaults; hard-code.
• C. Expose endpoints to set/update the default per user, and apply system default when not provided.
• D. Use only batch updates during nightly maintenance.

Answer: (C)

Exposing endpoints that let each user set or update their own default address, while using a system-wide default when none is provided, gives the right balance between customization and reliability. This approach lets users personalize their experience—shipping or billing can default to the address they actually use—without breaking in cases where a user hasn’t chosen one yet. It also keeps the system maintainable: defaults are managed through clear API calls, with real-time updates and proper auditing, rather than hard-coded values. Requiring a default every time would burden developers and users, making the API less friendly and flexible. Relying on nightly batch updates wouldn't reflect current user choices and could lead to mismatches or delays.