AWS API Gateway No 'Access-Control-Allow-Origin' header is present
Digitalkapitaen's answer is correct; here is the code to save someone the trouble of looking up how to set an HTTP response header in Lambda:
exports.handler = function(event, context, callback) {
callback(null, {
"statusCode": 200,
"headers": {
"Access-Control-Allow-Origin": "*"
}
});
};
The response for the GET request to the Lambda function must also contain the Access-Control-Allow-Origin
header.