I'm trying to create a Step Function to call LEX to get intents from text. Is it possible to call LEX using step functions or I need to use lambdas?
The documentation doesn't list LEX as a supported service, but I want to be 100% sure before committing to use lambdas.
Currently, it is not possible to invoke a Lex bot directly from Step Functions.
As you mentioned, if you have to do it, invoke a Lambda function from your Step Function. The Lambda function can then further use the Lex runtime API operations to invoke the Lex bot: https://docs.aws.amazon.com/lex/latest/dg/API_Operations_Amazon_Lex_Runtime_Service.html