API Gateway schema

I’m new to serverless framework, but we were interested of implementing it in our development as it cuts out much of the manual work needed in AWS console. I am however still trying to search any examples or docs regarding API Gateway schema in serverless. I want to be able to create a schema so that our API Gateway handles the incoming request validation instead of validating anything in Lambda.

We currently have a swagger file we use to create a CloudFormation change-set with using SAM template. Swagger contains the documentation and required parameters with required types, responses for resources etc. Can this be done in serverless and where can I find docs for it?