diff --git a/shopify-buy/shopify-buy-tests.ts b/shopify-buy/shopify-buy-tests.ts
index 3d8d1f5988..23dd7b3c68 100644
--- a/shopify-buy/shopify-buy-tests.ts
+++ b/shopify-buy/shopify-buy-tests.ts
@@ -5,7 +5,7 @@
 ============================================================ */
 let client = ShopifyBuy.buildClient({
     apiKey: 'bf081e860bc9dc1ce0654fdfbc20892d',
-    myShopifyDomain: 'embeds',
+    domain: 'embeds',
     appId: '6'
 });
 
@@ -34,7 +34,7 @@ client.fetchProduct('3614436099').then(function (fetchedProduct : ShopifyBuy.Sho
     product = fetchedProduct;
     var selectedVariant : ShopifyBuy.Shopify.ProductVariantModel = product.selectedVariant;
     var selectedVariantImage : any = product.selectedVariantImage;
-    var currentOptions : ShopifyBuy.Shopify.Option[] = product.options;
+    var currentOptions : ShopifyBuy.Shopify.ProductOptionModel[] = product.options;
 
     var variantSelectors = generateSelectors(product);
     $('.variant-selectors').html(""+variantSelectors);
@@ -51,7 +51,7 @@ client.fetchProduct('3614436099').then(function (fetchedProduct : ShopifyBuy.Sho
 /* Generate DOM elements for variant selectors
 ============================================================ */
 function generateSelectors(product : ShopifyBuy.Shopify.ProductModel) {
-    var elements = product.options.map(function(option : ShopifyBuy.Shopify.Option) {
+    var elements = product.options.map(function(option : ShopifyBuy.Shopify.ProductOptionModel) {
         var optionsHtml = option.values.map(function(value : any) {
             return '<option value="' + value + '">' + value + '</option>';
         });
@@ -127,7 +127,7 @@ function attachOnVariantSelectListeners(product : ShopifyBuy.Shopify.ProductMode
         var $element : any = $(event.target);
         var name : string = $element.attr('name');
         var value : string = $element.val();
-        product.options.filter(function(option : ShopifyBuy.Shopify.Option) {
+        product.options.filter(function(option : ShopifyBuy.Shopify.ProductOptionModel) {
             return option.name === name;
         })[0].selected = value;
 
@@ -172,7 +172,7 @@ function buyButtonClickHandler(evt : any) {
     evt.preventDefault();
     var id : string | number = product.selectedVariant.id;
     var quantity : number;
-    var cartLineItem : ShopifyBuy.Shopify.CartLineItem = findCartItemByVariantId(id);
+    var cartLineItem : ShopifyBuy.Shopify.CartLineItemModel = findCartItemByVariantId(id);
 
     quantity = cartLineItem ? cartLineItem.quantity + 1 : 1;
 
@@ -188,7 +188,7 @@ function updateQuantity(fn : Function, variantId : string | number) {
         return (variant.id === variantId);
     })[0];
     var quantity : number;
-    var cartLineItem : ShopifyBuy.Shopify.CartLineItem = findCartItemByVariantId(variant.id);
+    var cartLineItem : ShopifyBuy.Shopify.CartLineItemModel = findCartItemByVariantId(variant.id);
     if (cartLineItem) {
         quantity = fn(cartLineItem.quantity);
         updateVariantInCart(cartLineItem, quantity);
@@ -218,7 +218,7 @@ function fieldQuantityHandler(evt : any) {
     var variant : ShopifyBuy.Shopify.ProductVariantModel = product.variants.filter(function (variant : ShopifyBuy.Shopify.ProductVariantModel) {
         return (variant.id === variantId);
     })[0];
-    var cartLineItem : ShopifyBuy.Shopify.CartLineItem = findCartItemByVariantId(variant.id);
+    var cartLineItem : ShopifyBuy.Shopify.CartLineItemModel = findCartItemByVariantId(variant.id);
     var quantity : number = evt.target.value;
     if (cartLineItem) {
         updateVariantInCart(cartLineItem, quantity);
@@ -267,7 +267,7 @@ function findCartItemByVariantId(variantId : string | number) {
 ============================================================ */
 function addOrUpdateVariant(variant : ShopifyBuy.Shopify.ProductVariantModel, quantity : number) {
     openCart();
-    var cartLineItem : ShopifyBuy.Shopify.CartLineItem = findCartItemByVariantId(variant.id);
+    var cartLineItem : ShopifyBuy.Shopify.CartLineItemModel = findCartItemByVariantId(variant.id);
 
     if (cartLineItem) {
         updateVariantInCart(cartLineItem, quantity);
@@ -280,7 +280,7 @@ function addOrUpdateVariant(variant : ShopifyBuy.Shopify.ProductVariantModel, qu
 
 /* Update details for item already in cart. Remove if necessary
 ============================================================ */
-function updateVariantInCart(cartLineItem : ShopifyBuy.Shopify.CartLineItem, quantity : number) {
+function updateVariantInCart(cartLineItem : ShopifyBuy.Shopify.CartLineItemModel, quantity : number) {
     var variantId : string | number = cartLineItem.variant_id;
     var cartLength : number = cart.lineItems.length;
     cart.updateLineItem(cartLineItem.id, quantity).then(function(updatedCart : ShopifyBuy.Shopify.CartModel) {
@@ -311,7 +311,7 @@ function addVariantToCart(variant : ShopifyBuy.Shopify.ProductVariantModel, quan
     openCart();
 
     cart.addVariants({ variant: variant, quantity: quantity }).then(function() {
-        var cartItem : ShopifyBuy.Shopify.CartLineItem = cart.lineItems.filter(function (item : ShopifyBuy.Shopify.CartLineItem ) {
+        var cartItem : ShopifyBuy.Shopify.CartLineItemModel = cart.lineItems.filter(function (item : ShopifyBuy.Shopify.CartLineItemModel ) {
             return (item.variant_id === variant.id);
         })[0];
         var $cartItem = renderCartItem(cartItem);
@@ -332,7 +332,7 @@ function addVariantToCart(variant : ShopifyBuy.Shopify.ProductVariantModel, quan
 
 /* Return required markup for single item rendering
 ============================================================ */
-function renderCartItem(lineItem : ShopifyBuy.Shopify.CartLineItem) {
+function renderCartItem(lineItem : ShopifyBuy.Shopify.CartLineItemModel) {
     var lineItemEmptyTemplate = $('#CartItemTemplate').html();
     var $lineItemTemplate = $(lineItemEmptyTemplate);
     var itemImage = lineItem.image.src;
@@ -401,6 +401,6 @@ function updateCartTabButton() {
 
 /* Set previously focused item for escape handler
 ============================================================ */
-function setPreviousFocusItem(item : ShopifyBuy.Shopify.CartLineItem) {
+function setPreviousFocusItem(item : ShopifyBuy.Shopify.CartLineItemModel) {
     previousFocusItem = item;
 }
diff --git a/shopify-buy/shopify-buy.d.ts b/shopify-buy/shopify-buy.d.ts
index 18c9358b3b..9de8249804 100644
--- a/shopify-buy/shopify-buy.d.ts
+++ b/shopify-buy/shopify-buy.d.ts
@@ -1,4 +1,4 @@
-// Type definitions for shopify-buy
+// Type definitions for shopify-buy 0.4.2
 // Project: http://shopify.github.io/js-buy-sdk/api/
 // Definitions by: Martin Köhn <https://github.com/openminder>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
@@ -7,39 +7,54 @@
  * The JS Buy SDK is a lightweight library that allows you to build ecommerce into any website.
  * It is based on Shopify’s API and provides the ability to retrieve products and collections from your shop,
  * add products to a cart, and checkout.
+ * It can render data on the client side or server. This will allow you to add ecommerce functionality to any
+ * website or javascript application. This is helpful if you already have a website and need to add ecommerce
+ * or only need a simple buy button on your site.
  */
 declare namespace ShopifyBuy {
     /**
      * Create a ShopClient. This is the main entry point to the SDK.
      */
-    export function buildClient(configAttrs : Shopify.Config) : Shopify.ShopClient
+    export function buildClient(configAttrs: Shopify.Config): Shopify.ShopClient
 
     /**
      * Internal Image description
      */
     interface Image {
-        id : string|number
-        src : string
-        position : number
-        product_id : string
-        variant_ids : Array<string>
-        created_at : string
-        updated_at : string
+        id: string | number
+        created_at: string
+        position: number
+        updated_at: string
+        product_id: string
+        src: string
+        variant_ids: Array<string>
+    }
+
+    interface ImageVariant {
+        name: string,
+        dimensions: string,
+        src: string
+    }
+
+    interface OptionValue {
+        name: string,
+        option_id: string | number,
+        value: any
     }
 
     /**
      * Internal BaseModel class
      */
     class BaseModel {
-        constructor( attrs: any, metaAttrs: any )
+        constructor(attrs: any, metaAttrs: any)
 
-        attrs : any
+        attrs: any
         serializer: any
         adapter: any
         shopClient: any
     }
 
-    var NO_IMAGE_URI : string;
+    var NO_IMAGE_URI: string;
 
     /**
      * This namespace contains all globally accessible classes
@@ -49,89 +64,31 @@ declare namespace ShopifyBuy {
         /**
          * Base Shopify Client config object
          */
-        interface Config
-        {
+        interface Config {
             /**
-             *  Your api client's public token.
+             * An API Key for your store. Documentation how to get an API Key:
+             * https://help.shopify.com/api/sdks/js-buy-sdk/getting-started#api-key
              */
             apiKey: string
 
-            /** The app whose listings the client will be using.
-             * If you are just modifying a buy button, the buy-button's app id is.
-             * Otherwise, obtain the app id of the app you're modifying or extending.
+            /**
+             * Typically will be 6 which is the Buy Button App Id. For more info on App Id see:
+             * https://help.shopify.com/api/sdks/js-buy-sdk/getting-started#app-id
              */
             appId: string
 
-            /** You shop's myshopify.com domain. */
-            myShopifyDomain: string
+            /**
+             * Your shop's full myshopify.com domain. For example: embeds.myshopify.com
+             */
+            domain: string
         }
 
         /**
          * Cart item, that should be added to the card
          */
         interface CartModelItem {
-            variant : Shopify.ProductVariantModel
-            quantity : number
-        }
-
-        class CartLineItem extends BaseModel {
-          constructor()
-
-          /**
-           * Line item unique ID
-           */
-          id : string|number
-
-          /**
-           * Images associated with product.
-           */
-          image : Image
-
-          /**
-           * Product title
-           */
-          title: string
-
-          /**
-           * ID of selected variant
-           */
-          variant_id: string|number
-
-          /**
-           * Title of selected variant
-           */
-          variant_title: string
-
-          /**
-           * Number of selected items
-           */
-          quantity : number
-
-          /**
-           * Variant weight in grams
-           */
-          grams: number
-
-          /**
-           * ID of selected product
-           */
-          product_id: string|number
-
-          /**
-           * Price of variant, formatted as currency
-           */
-          price: string
-
-          /**
-           * Compare at price for variant formatted as currency.
-           */
-          compare_at_price: string
-
-          /**
-           * Calculated price for the number of variant in card
-           */
-          line_price: string
-
+            variant: Shopify.ProductVariantModel
+            quantity: number
         }
 
         /**
@@ -142,95 +99,53 @@ declare namespace ShopifyBuy {
             /**
              * Config data to be used throughout all API interaction
              */
-            constructor( config? : Config )
+            constructor(config?: Config)
             /**
-             * Creates a CartModel instance, optionally including attrs.
+             * Creates a CartModel instance.
              */
-            createCart(attrs? : any) : Promise<CartModel>
+            createCart(): Promise<CartModel>
 
             /**
-             * Updates an existing CartModel instance and persists it to localStorage.
+             * This function will return an Array of collections from your store
              */
-            updateCart(attrs? : any) : Promise<CartModel>
+            fetchAllCollections(): Promise<Array<any>>
+
+            /**
+             * This function will return an Array of products from your store
+             */
+            fetchAllProducts(): Promise<Array<ProductModel>>
 
             /**
              * Retrieve a previously created cart by its key.
              */
-            fetchCart(id : string) : Promise<CartModel>
+            fetchCart(id: string): Promise<CartModel>
 
             /**
              * Fetch one collection by its ID.
              */
-            fetchCollection(id : string|number) : Promise<any> //TODO: Find declaration for Collection
+            fetchCollection(id: string | number): Promise<any>
 
             /**
              * Fetch one product by its ID.
              */
-            fetchProduct(id: string|number) : Promise<ProductModel>
+            fetchProduct(id: string | number): Promise<ProductModel>
 
             /**
              * Fetches a list of collections matching a specified query.
              */
-            fetchQueryCollections(query? : any) : Promise<Array<any>>
+            fetchQueryCollections(query?: any): Promise<Array<any>>
 
             /**
              * Fetches a list of products matching a specified query.
              */
-            fetchQueryProducts(query? : any) : Promise<Array<ProductModel>>
-
-        }
-
-        /**
-         * Class for cart model
-         */
-        class CartModel extends BaseModel {
-
-            constructor()
+            fetchQueryProducts(query?: any): Promise<Array<ProductModel>>
 
             /**
-             * Get checkout URL for current cart
+             * This method looks up a reference in localStorage to the most recent cart.
+             * If one is not found, creates one. If the cart the reference points to doesn't exist,
+             * create one and store the new reference.
              */
-            checkoutUrl : string
-
-            /**
-             * get ID for current cart
-             */
-            id : string|number
-
-            /**
-             * Get current line items for cart
-             */
-            lineItems : Array<CartLineItem>
-
-            /**
-             * Get current subtotal price for all line items
-             */
-            subtotal: string
-
-            /**
-             * Gets the sum quantity of each line item
-             */
-            lineItemCount : number
-
-            /**
-             * Add items to cart. Updates cart's lineItems
-             */
-            addVariants(item : CartModelItem, nextItem? : Array<CartModelItem>) : Promise<CartModel>
-
-            /**
-             * Remove all line items from cart
-             */
-            clearLineItems() : Promise<CartModel>
-
-            /**
-             * Remove line item from cart
-             */
-            removeLineItem(id : string|number) : Promise<CartModel>
-
-            /**
-             * Update line item quantity
-             */
-            updateLineItem(id : string|number, quantitiy : number ) : Promise<CartModel>
+            fetchRecentCart(): Promise<CartModel>
 
         }
 
@@ -241,20 +156,20 @@ declare namespace ShopifyBuy {
 
             constructor()
 
+            /**
+             * A product description.
+             */
+            description: string
+
             /**
              * Product unique ID
              */
-            id : string|number
+            id: string | number
 
             /**
-             * All images associated with product.
+             * An Array of Objects that contain meta data about an image including src of the images.
              */
-            images : Array<Image>
-
-            /**
-             * Product title
-             */
-            title: string
+            images: Array<Image>
 
             /**
              * All variants of a product.
@@ -262,24 +177,34 @@ declare namespace ShopifyBuy {
             variants: Array<ProductVariantModel>
 
             /**
-             * Get array of options with nested values. Useful for creating UI for selecting options.
+             * Get an array of ProductOptionModels. ProductOptionModels can be used to define
+             * the currently selectedVariant from which you can get a checkout url (ProductVariantModel.checkoutUrl)
+             * or can be added to a cart (CartModel.createLineItemsFromVariants).
              */
-            options : Array<Option>
+            options: Array<ProductOptionModel>
 
             /**
-             * Retrieve variant for currently selected options
+             * Retrieve variant for currently selected options. By default the first value in each option is selected
+             * which means selectedVariant will never be null. With a selectedVariant you can
+             * create checkout url (ProductVariantModel.checkoutUrl) or
+             * it can be added to a cart (CartModel.createLineItemsFromVariants).
              */
-            selectedVariant : ProductVariantModel
+            selectedVariant: ProductVariantModel
 
             /**
-             * Retrieve image for currently selected variantImage
+             * Retrieve image for currently selected variantImage.
              */
-            selectedVariantImage : Image
+            selectedVariantImage: Image
 
             /**
-             * Retrieve currently selected option values.
+             * A read only Array of Strings represented currently selected option values. eg. ["Large", "Red"]
              */
-            selections : Option
+            selections: Array<string>
+
+            /**
+             * The product title
+             */
+            title: string
         }
 
         /**
@@ -290,49 +215,67 @@ declare namespace ShopifyBuy {
             constructor()
 
             /*
-             * Checkout URL for purchasing variant with quantity.
+             * Get a checkout url for a specific product variant.
+             * You can optionally pass a quantity.
+             * If no quantity is passed then quantity will default to 1.
              */
-            checkoutUrl( quantitiy : number ) : string
+            checkoutUrl(quantitiy: number): string
 
             /**
-             * Compare at price for variant formatted as currency.
+             * Variant in stock. Always true if inventory tracking is disabled.
              */
-            compareAtPrice : string
+            available: boolean
 
             /**
-             * Variant weight in grams
+             * Compare at price for variant. The compareAtPrice would be the price of the
+             * product previously before the product went on sale.
              */
-            grams : number
+            compareAtPrice: string
+
+            /**
+             * Price of variant, formatted according to shop currency format string. For instance "$10.00"
+             */
+            formattedPrice: string
+
+            /**
+             * Variant weight in grams. If no weight is defined grams will be 0.
+             */
+            grams: number
 
             /**
              * Variant unique ID
              */
-            id : string|number
+            id: string | number
 
             /**
              * Image for variant
              */
-            image : Image
+            image: Image
+
+            /**
+             * Image variants available for a variant.
+             */
+            imageVariant: Array<ImageVariant>
 
             /**
              * Option values associated with this variant, ex {name: "color", value: "Blue"}
             */
-            optionValues : Array<Option>
+            optionValues: Array<OptionValue>
 
             /**
-             * Price of variant, formatted as currency
+             * Price of the variant. The price will be in the following form: "10.00"
              */
-            price : string
+            price: string
 
             /**
              * ID of product variant belongs to
              */
-            productId : string|number
+            productId: string | number
 
             /**
              * Title of product variant belongs to
              */
-            productTitle : string
+            productTitle: string
 
             /**
              * Title of variant
@@ -343,7 +286,7 @@ declare namespace ShopifyBuy {
         /**
          * Class for product option
          */
-        class Option extends BaseModel {
+        class ProductOptionModel extends BaseModel {
 
             constructor()
 
@@ -353,16 +296,149 @@ declare namespace ShopifyBuy {
             name: string
 
             /**
-             * get/set selected option value (ex. "Large").
-             * Setting this will update the selected value on the model.
-             * Throws {Error} if setting selected to value that does not exist for option
+             * get/set the currently selected option value with one of the values from the ProductOptionModel/values array.
+             * For instance if the option values array had the following ["Large", "Medium", "Small"] setting selected to be
+             * "Large", "Medium", or "Small" would be valid any other value would throw an Error.
              */
-            selected : string
+            selected: string
 
             /**
-             * possible values for selection
+             * an Array possible values for option. For instance if this option
+             * is a "Size" option an example value for values could be: ["Large", "Medium", "Small"]
              */
-            values : Array<any>
+            values: Array<any>
+
+        }
+
+        /**
+         * Class for cart model
+         */
+        class CartModel extends BaseModel {
+
+            constructor()
+
+            /**
+             * Remove all line items from cart
+             */
+            clearLineItems(): Promise<CartModel>
+
+            /**
+             * Add items to cart. Updates cart's lineItems
+             */
+            addVariants(item: CartModelItem, nextItem?: Array<CartModelItem>): Promise<CartModel>
+
+            /**
+             * Add items to the cart. Updates cart's lineItems based on variants passed in.
+             */
+            createLineItemsFromVariants(...items: CartModelItem[] ): Promise<CartModel>
+
+            /**
+             * Remove a line item from cart based on line item id
+             */
+            removeLineItem(id: string | number): Promise<CartModel>
+
+            /**
+             * Update a line item quantity based on line item id
+             */
+            updateLineItem(id: string | number, quantitiy: number): Promise<CartModel>
+
+            /**
+             * Force update of cart model on server. This function will only be used in advanced
+             * situations and does not need to be called explicitly to update line items.
+             * It is automatically called after createLineItemsFromVariants, updateLineItem,
+             * removeLineItem, and removeLineItem
+             */
+            updateModel(): Promise<CartModel>
+
+            /**
+             * Get checkout URL for current cart
+             */
+            checkoutUrl: string
+
+            /**
+             * get ID for current cart
+             */
+            id: string | number
+
+            /**
+             * Gets the total quantity of all line items. Example: you've added two variants
+             * with quantities 3 and 2. lineItemCount will be 5.
+             */
+            lineItemCount: number
+
+            /**
+             * Get an Array of CartLineItemModel's
+             */
+            lineItems: Array<CartLineItemModel>
+
+            /**
+             * Get current subtotal price for all line items.
+             * Example: two items have been added to the cart that cost $1.25 then the subtotal will be 2.50
+             */
+            subtotal: string
+
+        }
+
+        class CartLineItemModel extends BaseModel {
+            constructor()
+
+            /**
+             * Compare at price for variant. The compareAtPrice would be the price of the product
+             * previously before the product went on sale.
+             * If no compareAtPrice is set then this value will be null. An example value: "5.00".
+             */
+            compare_at_price: string
+
+            /**
+             * Variant's weight in grams. If no weight is set then 0 is returned.
+             */
+            grams: number
+
+            /**
+             * A line item ID.
+             */
+            id: string | number
+
+            /**
+             * Variant's image.
+             */
+            image: Image
+
+            /**
+             * The total price for this line item. For instance if the variant costs 1.50 and you have a
+             * quantity of 2 then line_price will be 3.00.
+             */
+            line_price: string
+
+            /**
+             * Price of the variant. For example: "5.00".
+             */
+            price: string
+
+            /**
+             * ID of variant's product.
+             */
+            product_id: string | number
+
+            /**
+             * Count of variants to order.
+             */
+            quantity: number
+
+            /**
+             * Product title of variant's parent product.
+             */
+            title: string
+
+            /**
+             * ID of line item variant.
+             */
+            variant_id: string | number
+
+            /**
+             * Title of variant.
+             */
+            variant_title: string
 
         }
 
@@ -370,6 +446,6 @@ declare namespace ShopifyBuy {
 
 }
 
-declare module "ShopifyBuy" {
+declare module "shopify-buy" {
     export = ShopifyBuy
 }