CORS is a mechanism that allows a web application running at one domain (origin) to access selected resources from a different server. Without CORS, the server will respond with a status code of 403 in such cases. We will create an API gateway service similar to what we did in Chapter 2, Building Serverless REST APIs with API Gateway, but will also enable CORS on the API.
We will first get familiar with the CodePen website and will test our API by invoking it using JavaScript SDK code from within the CodePen website. This will also be a revision of the API Gateway concepts that we learned in Chapter 2, Building Serverless REST APIs with API Gateway, but with the additional support for CORS. We will only discuss new concepts here; for theory on already discussed topics, you may refer to the recipes of Chapter 2, Building Serverless...