Amazon EventBridge vs Karapace

Amazon EventBridge is a serverless event broker for applications that respond to events from applications, SaaS services, and AWS services. Event buses route events across AWS accounts, and subscriptions can combine filters, targets, and retry policies. Buses support tens of thousands of subscribers, retention for up to 365 days, and JSON, Avro, Protobuf, and Cloud Events formats. EventBridge also supports ordered delivery and sharing a bus across accounts in an AWS Organization through AWS Resource Access Manager. Pipes connect endpoints point to point, with optional transformation, filtering, and enrichment. Supported SaaS sources can route events to AWS service targets; listed partners include Adobe, Datadog, MongoDB, Shopify, Stripe, and Snyk. API destinations send events from a bus or pipe to web applications on public or private networks. Monitoring uses CloudWatch metrics, with logging to CloudWatch Logs, S3, or Kinesis Data Firehose. IAM access controls, VPC endpoints, and TLS 1.2 encryption in transit are supported. AWS lists several compliance standards and HIPAA eligibility, while customers retain responsibility for their own compliance obligations.

Karapace is Aiven’s open-source Schema Registry and REST Proxy for Aiven for Apache Kafka. The registry stores and versions schemas, then checks compatibility before a changed schema is published. It accepts Avro, Protobuf, and JSON Schema, with references supported for Avro and Protobuf. Compatibility modes include NONE, BACKWARD, BACKWARD_TRANSITIVE, FORWARD, FORWARD_TRANSITIVE, FULL, and FULL_TRANSITIVE. The REST Proxy exposes HTTP endpoints for producing and consuming Kafka events, so scripts, curl, and HTTP services can work with events. OAuth 2.0/OIDC authentication is available for both components. Registry ACLs and OIDC role-based rules can limit operations, including by HTTP method. Example identity providers include Auth0, Okta, Google Identity Platform, and Azure. Deployment documentation covers Docker and installation from source with pip; the API is stated to support Schema Registry 6.1.1 operations. Karapace is available in Aiven’s Kafka free tier for learning, prototyping, and evaluation. The Free plan costs nothing, while Developer costs $35 a month.