EventBridge

EventBridge is a serverless event bus service provided by Amazon Web Services (AWS) that enables event-driven architectures by routing events from producers to targets. Introduced as an evolution of CloudWatch Events, it broadens the scope of event routing to include custom events, SaaS partner events, and real-time processing workflows.

The core concepts of EventBridge are event buses, events, rules, and targets. Producers publish events to an event bus, and each event contains fields such as source, detail-type, and detail. Users create rules that define event patterns to match specific types of events; when a match occurs, the event is sent to one or more targets, which can include AWS Lambda functions, Step Functions state machines, Simple Queue Service (SQS) queues, Simple Notification Service (SNS) topics, Kinesis services, API destinations, or ECS tasks. EventBridge also supports scheduled events via cron or rate expressions, enabling time-based workflows. In addition, it provides multiple buses, including default, custom, and partner buses for SaaS integrations.

Key features include support for SaaS integrations through partner event buses, cross-account event sharing via resource-based policies, a schema registry and discovery service for event structure, and an archive and replay capability to retain and replay events for testing or recovery. EventBridge also offers Eco-system components such as EventBridge Pipes for connecting event streams to targets with transformation and filtering.

Usage patterns typically involve decoupled microservices, real-time data processing, and seamless integration with third-party SaaS applications. Pricing is generally based on the number of events published or matched, with a per-event cost and a data transfer component; events are limited in size to 256 KB.