Yes, it is possible to add to the shopping cart an entire project or even just a part of the products that are in it. This applies to both private and public projects (the whole procedure takes place within the project tab).

To add the whole project to the cart just click on the button "Add Project to Cart" which is located at the bottom right at the end of the list of products.

If instead you want to add to cart only certain products, select them by checking the box at the top left of each product line. Once you have selected the products, click on the "Multiple selection" dropdown menu at the top of the product list - next to the project description, and select "Add to cart selected". If your project contains many products, take advantage of Multiple Selection.

If you don't see the products added right away from the cart preview, try reloading the page.