We are using EventBridge fairly extensively, and our current architecture w/ Retool requires invoking a Lambda (either directly, or via API Gateway).
AWS EventBridge provides it's own API, that can be authenticated/authorized by IAM.
https://docs.aws.amazon.com/eventbridge/latest/APIReference/Welcome.html
Even further to the integration with EventBridge would be to integrate AWS Schema Registry, so that users are able to introspect the schema, and send correct payloads with relative ease. Right now we are using JSON.stringify({})
with our payload object which obviously has no typing.