Is app necessary for shopify integration?? by James

Hi,

I'm new in the e commerce integration.

I have studied documents regarding API and Oauth2 protocol. But the problem is, I have to integrate my web application with shopify, but I don't want to create any public or private app for this. So that, is there any possible way to achieve the shopify integration with my web app with out creating an app?? 

Thanks !!