Cross-Origin Resource Sharing

Outcome: Complete the task with Cross-Origin Resource Sharing (CORS). User context: Un panel en app.example.com llama a api.example.net. La API revisa el preflight antes de las escrituras autenticadas y solo permite el origen de producción. Technical concept or control: Cross-Origin Resource Sharing (CORS). Why it fits: Configure CORS en el servidor o gateway cuando el código del navegador deba leer otro origen. Do not use it when: No uses orígenes con comodín junto con credenciales ni devuelvas orígenes desconocidos. CORS no reemplaza la autenticación ni la protección CSRF. Engineering requirements: Define inputs, outputs, contracts, and rules that must always hold. Set authorization and input checks. Define failures, timeouts, retries, one-time effects, data moves, and compatibility limits. Operations: Add useful signals and logs that hide sensitive data. Set capacity limits and write an operator guide. Test recovery and rollback. Acceptance criteria: Contract and failure-path tests pass. Data and authorization rules still hold during retries and partial failures. Check performance limits, monitoring, recovery, and rollback. Evidence and limits (evidence boundary): El estándar cubre únicamente el alcance listado. No elige el estilo visual, la decisión del producto ni el ejemplo de Vibulary. Unknowns to confirm: Where the code runs, data stores, traffic shape, consistency needs, and the security boundary. Also confirm the compatibility period, service goals, and rollback limits.