Here's a link to the Commerce service's README.txt which includes a bit more detail on what kind of abilities it brings out of the box.
The following grid indicates what callbacks have been defined so far
out of the current target set of resources:
Resource | Index | Retrieve | Create | Update | Delete
-----------------|-------|----------|--------|--------|--------
product-displays | Y | Y | - | - | -
products | N | N | - | - | -
carts | N | - | - | - | -
orders | N | N | N | N | N
The additional relationships and targeted actions are slated for
development:
product-displays: products products: add to cart carts: empty, convert
orders: payments
So then the question is: Can you do what you want with commerce_services?
Can you create a product? Not according to the README
Can you add a product to a cart? Not according to the README
Commerce Services Implementations
section here contain functioning examples related to JavaScript: github.com/signalpoint/commerce/blob/7.x-1.x/commerce.js – tyler.frankenstein Jul 24 '15 at 12:15