Jason Judge

Allows access to custom meta fields on products through the API. 
In short, installing this plugin on your WooCommerce site, will extend the 
WooCommerce API so that custom metadata can be passed back and forth through 
that API.
See the main documentation here: https://github.com/judgej/wc-api-custom-meta

WC API Custom Meta

Awesome!

Allows access to custom meta fields on products through the API.

WP BackOffice

While WooCommerce’s REST Api (v2.1+) allows easy integration with your favorite 3rd party services, it also opens the doors for users to access all of your store details including:
<ul>
<li>Order Details</li>
<li>Customer Details</li>
<li>Product Information</li>
<li>Coupon Codes</li>
<li>Store Reports</li>
</ul>
WooCommerce API Lockdown allows you to restrict what is available through your API on a site wide or per user basis with an easy to use admin panel.
Usage
<ol>
<li>Once installed, in your WordPress backend navigate to to ‘WooCommerce’ -> ‘API Lockdown’</li>
<li>Select any site wide restrictions </li>
<li>Select any users specific restrictions</li>
<li>Click update that that’s it.</li>
</ol>
What Happens when a Restricted User Tries to Gain Access?
If a user tries to access a section they don’t have access to they will simply get a Authentication Error.
<a href="http://wpbackoffice.com/plugins/woocommerce-api-lockdown/" rel="nofollow ugc">Plugin’s Official Documentation and Support Page</a>

WooCommerce API Lockdown

Protect your data by restricting what is available through your WooCommerce REST API on a site wide or per user basis.

WC API Custom Meta vs WooCommerce API Lockdown