What problem does it solve? Standard REST calls must return within 1-2 seconds, but operations like PDF generation or data export take longer. This Skill provides proven patterns to handle long-running operations without blocking HTTP threads or degrading API responsiveness. ## Core Features & Use Cases - Submit-Poll-Result Pattern: Return 202 Accepted with a jobId and Location header, expose a status endpoint with a clear state machine (PENDING, PROCESSING, COMPLETED, FAILED), and support long polling via Wait-For headers. - Webhook Notifications: Let clients provide a callbackUrl, sign payloads with HMAC-SHA256, and retry failed callbacks with exponential backoff before moving to a Dead Letter Queue. - Server-Sent Events: Push real-time status updates to UI clients over a single HTTP connection using Spring Boot SseEmitter. - Use Case: A client requests a large data export. The API returns 202 with a jobId, the client polls the status endpoint or receives a signed webhook when done, then downloads the artifact from a separate URL. Old jobs are cleaned up automatically via TTL. ## Quick Start Apply the async-api-patterns skill to design an asynchronous endpoint for my long-running report generation operation.
