Snipcart

Snipcart is a shopping cart platform for any website. Using simple HTML buy buttons and a flexible JavaScript shopping cart, you can enable e-commerce on your site in minutes. All of your e-commerce operations can then be managed in a comprehensive, hosted merchant dashboard. Testing if forever free, no credit card required. Snipcart is a flexible shopping cart developers can easily integrate into any website in minutes. After injecting a snippet of JS to your project, you can define products directly in your HTML.

All of your e-commerce logic can effectively be handled in the frontend, which makes it easy to integrate in web apps, static sites, or even old school CMS.