diff --git a/README.md b/README.md
index 60808c5..97a7b49 100644
--- a/README.md
+++ b/README.md
@@ -185,10 +185,10 @@ To create a file using the SDK, you need to have the file on disk:
 
 ```php
 // create a file from a local disk
-$moltin->files->create(['public' => 'true'], '/path/to/file.jpg');
+$moltin->files->create(['public' => 'true', 'file' => '/path/to/file.jpg']);
 
 // create a file from a URL (note: this will download the file to your local disk then upload)
-$moltin->files->create(['public' => 'true'], 'https://placeholdit.imgix.net/~text?&w=350&h=150');
+$moltin->files->create(['public' => 'true', 'file' => 'https://placeholdit.imgix.net/~text?&w=350&h=150']);
 ```
 
 ### Integrations
diff --git a/src/Resource.php b/src/Resource.php
index aa6f786..ac8b29f 100644
--- a/src/Resource.php
+++ b/src/Resource.php
@@ -16,15 +16,16 @@ class Resource
     protected $relationshipTypeMap = [
         'brands' => 'brand',
         'categories' => 'category',
-        'children' => 'category',
         'collections' => 'collection',
+        'children' => 'category',
         'files' => 'file',
+        'main-image' => 'main_image',
+        'options' => 'variation-option',
         'parent' => 'category',
         'products' => 'product',
+        'product-modifiers' => 'product-modifier',
         'variations' => 'variation',
-        'variation-options' => 'variation-option',
-        'options' => 'variation-option',
-        'product-modifiers' => 'product-modifier'
+        'variation-options' => 'variation-option'
     ];
 
     // the \Moltin\Client