Saving an entity back to Drupal

Following is some sample jQuery code which illustrates the simplest use case for saving entity data back to Drupal.

jQuery.ajax({
    url: "http://mydrupalsite.com/api/v1.0/entity-endpoint-name",
    type: "POST",
    headers: {
        "Content-Type": "application/json",
    },
    contentType: "application/json",
    data: JSON.stringify({
        "property_one": "5",
        "property_two": "4",
        "etc": "abc"
    })
})
.done(function(data, textStatus, jqXHR) {
    console.log("HTTP Request Succeeded: " + jqXHR.status);
    console.log(data);
})
.fail(function(jqXHR, textStatus, errorThrown) {
    console.log("HTTP Request Failed");
})
.always(function() {
    /* ... */
});

The properties contained in the data element correspond with those you defined in your custom Drupal module's publicFields() function for this entity type.