I have an use-case to process and aggregate real-time data using Kinesis data analytics.
Is it possible to publish data to kinesis streams directly from Appsync (without an intermediate lambda) ?
And also to trigger subscription back from kinesis streams ?
publishing to kinesis is possible using the HTTP data source in appsync. Here's their reference for how to set it up for internal aws services with auth: https://docs.aws.amazon.com/appsync/latest/devguide/tutorial-http-resolvers-js.html#invoking-aws-services-js
There isn't a way to get the message from kinesis into appsync without some intermediary step. The intermediary step (I would use a lambda) would need to listen to the kinesis stream and then send the payload as a mutation to the appsync api.