Check out our example on github https://github.com/awslabs/aws-serverless-express/tree/maste.... The lambda wrapper is very thin (4 LOC). So you have two options: run/test your express app locally as you always would, or use the provided `npm run local` command which simulates the API Gateway+Lambda part (you can modify the `api-gateway-event.json` to change the "request" from API Gateway). This is primarily an example and starting point, and there is much more you could do to improve this process.