emitting-api-events

# Emitting API Events ## Overview Build event-driven API architectures using outbound webhooks, Server-Sent Events (SSE), and message broker integration. Implement event emission from API mutations, event schema registry, subscriber management, delivery guarantees with retry logic, and event sourcing patterns for maintaining a complete audit log of API state changes. ## Prerequisites - Message broker: Redis Pub/Sub, RabbitMQ, Apache Kafka, or AWS SNS/SQS - Persistent storage for event log and subscriber registrations (PostgreSQL, MongoDB) - Webhook delivery infrastructure with retry queue (Bull, Celery, or managed service) - Event schema registry for versioned event type definitions - SSE-capable web framework for real-time event streaming to browser clients ## Instructions 1. Identify event-producing operations using Grep and Read, cataloging every API mutation (POST, PUT, PATCH, DELETE) that should emit events, with event type names following `resource.action` convention (e.g., `order.created`, `user.updated`). 2. Define event schemas for each event type with versioning: include `eventId` (UUID), `eventType`, `version`, `timestamp` (ISO 8601), `source` (service identifier), and `data` (type-specific payload). 3. Implement the event emitter service that publishes events to the message broker after successful API mutations, using the transactional outbox pattern to ensure events are not lost on application crash. 4. Build a webhook subscription management API: `POST /we...