AWS API Gateway endpoint gives CORS error when POST from static site on S3

Question

I have created an API endpoint with Serverless(serverless.com) which I expose through API Gateway. I\'m getting following error though I have enabled CORS from the

Answer 1

I would start troubleshooting by inspecting your API in the AWS Console to make sure serverless registered everything the way you expect.

1. Load the AWS Console and navigate to the API Gateway service.
2. Click the API to open it up.
3. Find your /signup resource
4. Make sure you see the OPTIONS method under /signup

5. Click each resource including options and check the following:

   a. Click Integration Response, click the arrow in the first row of the table for 200 to open it up.

   b. Click the arrow to open Header Mappings

   c. Make sure you see Access-Control-Allow-Origin mapped to '*'

If you find this header missing from one of the methods a quick fix is to click back on the /signup Resource and click the Enable CORS button. AWS will build out OPTIONS and the header mappings on all methods for you. Of course you still need to figure out why serverless didn't set things up for you but this will at least get you going.

Another note about the Enable CORS button, if you add another method later you'll have to click it again to re-run the tool to setup your new method with CORS.