Create a post with categories

gocat.js

// Create a new post
var post = new wp.api.models.Posts({ title:'new test' } );
post.save();

// Get a collection of the post's categories
var postCategories = post.getCategories();

// The new post has an single Category: Uncategorized
postCategories.at( 0 ).get('name');
// response -> "Uncategorized"

// Get all the categories
var allCategories = new wp.api.collections.Categories();
allCategories.fetch();

var appleCategory = allCategories.findWhere( { slug: 'apples' } );

// Add the category to the postCategories collection
appleCategory.set( 'parent_post', post.get( 'id' ) );
postCategories.create( appleCategory.toJSON(), { type: 'POST' } );

// Remove the Uncategorized category
postCategories.at( 0 ).destroy();

// Check the results - refectch
postCategories = post.getCategories();

postCategories.at( 0 ).get('name');
// response -> "apples"