diff --git a/docs/accounting/LineItem.md b/docs/accounting/LineItem.md
index 38b4e9dc..8d690d3c 100644
--- a/docs/accounting/LineItem.md
+++ b/docs/accounting/LineItem.md
@@ -14,10 +14,10 @@ Name | Type | Description | Notes
 **tax_type** | **String** | The tax type from TaxRates | [optional] 
 **tax_amount** | **BigDecimal** | The tax amount is auto calculated as a percentage of the line amount (see below) based on the tax rate. This value can be overriden if the calculated <TaxAmount> is not correct. | [optional] 
 **item** | [**LineItemItem**](LineItemItem.md) |  | [optional] 
-**line_amount** | **BigDecimal** | If you wish to omit either of the <Quantity> or <UnitAmount> you can provide a LineAmount and Xero will calculate the missing amount for you. The line amount reflects the discounted price if a DiscountRate has been used . i.e LineAmount = Quantity * Unit Amount * ((100 – DiscountRate)/100) | [optional] 
+**line_amount** | **BigDecimal** | If you wish to omit either the Quantity or UnitAmount you can provide a LineAmount and Xero will calculate the missing amount for you. The line amount reflects the discounted price if either a DiscountRate or DiscountAmount has been used i.e. LineAmount = Quantity * Unit Amount * ((100 - DiscountRate)/100) or LineAmount = (Quantity * UnitAmount) - DiscountAmount | [optional] 
 **tracking** | [**Array<LineItemTracking>**](LineItemTracking.md) | Optional Tracking Category – see Tracking.  Any LineItem can have a  maximum of 2 <TrackingCategory> elements. | [optional] 
 **discount_rate** | **BigDecimal** | Percentage discount being applied to a line item (only supported on  ACCREC invoices – ACC PAY invoices and credit notes in Xero do not support discounts | [optional] 
-**discount_amount** | **BigDecimal** | Discount amount being applied to a line item. Only supported on ACCREC invoices - ACCPAY invoices and credit notes in Xero do not support discounts. | [optional] 
+**discount_amount** | **BigDecimal** | Discount amount being applied to a line item. Only supported on ACCREC invoices and quotes. ACCPAY invoices and credit notes in Xero do not support discounts. | [optional] 
 **repeating_invoice_id** | **String** | The Xero identifier for a Repeating Invoice | [optional] 
 
 ## Code Sample
diff --git a/docs/accounting/index.html b/docs/accounting/index.html
index 49ec3474..e71cee26 100644
--- a/docs/accounting/index.html
+++ b/docs/accounting/index.html
@@ -3577,7 +3577,7 @@
     },
     "LineAmount" : {
       "type" : "number",
-      "description" : "If you wish to omit either of the <Quantity> or <UnitAmount> you can provide a LineAmount and Xero will calculate the missing amount for you. The line amount reflects the discounted price if a DiscountRate has been used . i.e LineAmount = Quantity * Unit Amount * ((100 – DiscountRate)/100)",
+      "description" : "If you wish to omit either the Quantity or UnitAmount you can provide a LineAmount and Xero will calculate the missing amount for you. The line amount reflects the discounted price if either a DiscountRate or DiscountAmount has been used i.e. LineAmount = Quantity * Unit Amount * ((100 - DiscountRate)/100) or LineAmount = (Quantity * UnitAmount) - DiscountAmount",
       "format" : "double",
       "x-is-money" : true
     },
@@ -3596,7 +3596,7 @@
     },
     "DiscountAmount" : {
       "type" : "number",
-      "description" : "Discount amount being applied to a line item. Only supported on ACCREC invoices - ACCPAY invoices and credit notes in Xero do not support discounts.",
+      "description" : "Discount amount being applied to a line item. Only supported on ACCREC invoices and quotes. ACCPAY invoices and credit notes in Xero do not support discounts.",
       "format" : "double",
       "x-is-money" : true
     },
@@ -6069,7 +6069,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="Accounting"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="Accounting"><strong>VSN: </strong>3.14.0</li>
+              <li class="nav-header" data-group="Accounting"><strong>VSN: </strong>3.15.0</li>
               <li class="nav-header" data-group="Accounting"><a href="#api-Accounting">Methods</a></li>
               <li data-group="Accounting" data-name="createAccount" class="">
                 <a href="#api-Accounting-createAccount">createAccount</a>
diff --git a/docs/app_store/AppStoreApi.md b/docs/app_store/AppStoreApi.md
index 8f757bca..09812e06 100644
--- a/docs/app_store/AppStoreApi.md
+++ b/docs/app_store/AppStoreApi.md
@@ -5,6 +5,9 @@ All URIs are relative to *https://api.xero.com/appstore/2.0*
 Method | HTTP request | Description
 ------------- | ------------- | -------------
 [**get_subscription**](AppStoreApi.md#get_subscription) | **GET** /subscriptions/{subscriptionId} | Retrieves a subscription for a given subscriptionId
+[**get_usage_records**](AppStoreApi.md#get_usage_records) | **GET** /subscriptions/{subscriptionId}/usage-records | Gets all usage records related to the subscription
+[**post_usage_records**](AppStoreApi.md#post_usage_records) | **POST** /subscriptions/{subscriptionId}/items/{subscriptionItemId}/usage-records | Send metered usage belonging to this subscription and subscription item
+[**put_usage_records**](AppStoreApi.md#put_usage_records) | **PUT** /subscriptions/{subscriptionId}/items/{subscriptionItemId}/usage-records/{usageRecordId} | Update and existing metered usage belonging to this subscription and subscription item
 
 
 
@@ -69,3 +72,199 @@ Name | Type | Description  | Notes
 - **Content-Type**: Not defined
 - **Accept**: application/json
 
+
+## get_usage_records
+
+> UsageRecordsList get_usage_records(subscription_id)
+
+Gets all usage records related to the subscription
+
+### Example
+
+```ruby
+# load the gem
+require 'xero-ruby'
+
+creds = {
+  client_id: ENV['CLIENT_ID'],
+  client_secret: ENV['CLIENT_SECRET'],
+  redirect_uri: ENV['REDIRECT_URI'],
+  scopes: ENV['SCOPES']
+}
+xero_client = XeroRuby::ApiClient.new(credentials: creds)
+
+token_set = fetch_valid_token_set(user) # example
+
+xero_client.refresh_token_set(token_set)
+
+# You need to namespace your api method call to one of the following api sets
+# [:accounting_api, :assets_api, :projects_api, :files_api, :payroll_au_api, :payroll_nz_api, :payroll_uk_api, :app_store_api]
+
+api_instance = xero_client.<api_set>
+
+
+
+subscription_id = '00000000-0000-0000-0000-000000000000' # String | Unique identifier for Subscription object
+begin
+  #Gets all usage records related to the subscription
+  result = api_instance.get_usage_records(subscription_id)
+  p result
+rescue XeroRuby::AppStore::ApiError => e
+  puts "Exception when calling AppStoreApi->get_usage_records: #{e}"
+end
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **subscription_id** | [**String**](.md)| Unique identifier for Subscription object | 
+
+### Return type
+
+[**UsageRecordsList**](UsageRecordsList.md)
+
+### Authorization
+
+[OAuth2](../README.md#OAuth2)
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/json
+
+
+## post_usage_records
+
+> UsageRecord post_usage_records(subscription_id, subscription_item_id, create_usage_record)
+
+Send metered usage belonging to this subscription and subscription item
+
+### Example
+
+```ruby
+# load the gem
+require 'xero-ruby'
+
+creds = {
+  client_id: ENV['CLIENT_ID'],
+  client_secret: ENV['CLIENT_SECRET'],
+  redirect_uri: ENV['REDIRECT_URI'],
+  scopes: ENV['SCOPES']
+}
+xero_client = XeroRuby::ApiClient.new(credentials: creds)
+
+token_set = fetch_valid_token_set(user) # example
+
+xero_client.refresh_token_set(token_set)
+
+# You need to namespace your api method call to one of the following api sets
+# [:accounting_api, :assets_api, :projects_api, :files_api, :payroll_au_api, :payroll_nz_api, :payroll_uk_api, :app_store_api]
+
+api_instance = xero_client.<api_set>
+
+
+
+subscription_id = '00000000-0000-0000-0000-000000000000' # String | Unique identifier for Subscription object
+subscription_item_id = '00000000-0000-0000-0000-000000000000' # String | The unique identifier of the subscriptionItem
+create_usage_record = { "timestamp": "2022-01-21T13:01:00Z", "quantity": 10 } # CreateUsageRecord | Contains the quantity for the usage record to create
+begin
+  #Send metered usage belonging to this subscription and subscription item
+  result = api_instance.post_usage_records(subscription_id, subscription_item_id, create_usage_record)
+  p result
+rescue XeroRuby::AppStore::ApiError => e
+  puts "Exception when calling AppStoreApi->post_usage_records: #{e}"
+end
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **subscription_id** | [**String**](.md)| Unique identifier for Subscription object | 
+ **subscription_item_id** | [**String**](.md)| The unique identifier of the subscriptionItem | 
+ **create_usage_record** | [**CreateUsageRecord**](CreateUsageRecord.md)| Contains the quantity for the usage record to create | 
+
+### Return type
+
+[**UsageRecord**](UsageRecord.md)
+
+### Authorization
+
+[OAuth2](../README.md#OAuth2)
+
+### HTTP request headers
+
+- **Content-Type**: application/json
+- **Accept**: application/json
+
+
+## put_usage_records
+
+> UsageRecord put_usage_records(subscription_id, subscription_item_id, usage_record_id, update_usage_record)
+
+Update and existing metered usage belonging to this subscription and subscription item
+
+### Example
+
+```ruby
+# load the gem
+require 'xero-ruby'
+
+creds = {
+  client_id: ENV['CLIENT_ID'],
+  client_secret: ENV['CLIENT_SECRET'],
+  redirect_uri: ENV['REDIRECT_URI'],
+  scopes: ENV['SCOPES']
+}
+xero_client = XeroRuby::ApiClient.new(credentials: creds)
+
+token_set = fetch_valid_token_set(user) # example
+
+xero_client.refresh_token_set(token_set)
+
+# You need to namespace your api method call to one of the following api sets
+# [:accounting_api, :assets_api, :projects_api, :files_api, :payroll_au_api, :payroll_nz_api, :payroll_uk_api, :app_store_api]
+
+api_instance = xero_client.<api_set>
+
+
+
+subscription_id = '00000000-0000-0000-0000-000000000000' # String | Unique identifier for Subscription object
+subscription_item_id = '00000000-0000-0000-0000-000000000000' # String | The unique identifier of the subscriptionItem
+usage_record_id = '00000000-0000-0000-0000-000000000000' # String | The unique identifier of the usage record
+update_usage_record = { "quantity": 10 } # UpdateUsageRecord | Contains the quantity for the usage record to update
+begin
+  #Update and existing metered usage belonging to this subscription and subscription item
+  result = api_instance.put_usage_records(subscription_id, subscription_item_id, usage_record_id, update_usage_record)
+  p result
+rescue XeroRuby::AppStore::ApiError => e
+  puts "Exception when calling AppStoreApi->put_usage_records: #{e}"
+end
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **subscription_id** | [**String**](.md)| Unique identifier for Subscription object | 
+ **subscription_item_id** | [**String**](.md)| The unique identifier of the subscriptionItem | 
+ **usage_record_id** | [**String**](.md)| The unique identifier of the usage record | 
+ **update_usage_record** | [**UpdateUsageRecord**](UpdateUsageRecord.md)| Contains the quantity for the usage record to update | 
+
+### Return type
+
+[**UsageRecord**](UsageRecord.md)
+
+### Authorization
+
+[OAuth2](../README.md#OAuth2)
+
+### HTTP request headers
+
+- **Content-Type**: application/json
+- **Accept**: application/json
+
diff --git a/docs/app_store/CreateUsageRecord.md b/docs/app_store/CreateUsageRecord.md
new file mode 100644
index 00000000..0ae33a55
--- /dev/null
+++ b/docs/app_store/CreateUsageRecord.md
@@ -0,0 +1,19 @@
+# XeroRuby::AppStore::CreateUsageRecord
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**quantity** | **Integer** | The initial quantity for the usage record. Must be a whole number that is greater than or equal to 0 | 
+**timestamp** | **DateTime** | DateTime in UTC of when the the product was consumed/used | 
+
+## Code Sample
+
+```ruby
+require 'XeroRuby::AppStore'
+
+instance = XeroRuby::AppStore::CreateUsageRecord.new(quantity: null,
+                                 timestamp: null)
+```
+
+
diff --git a/docs/app_store/UpdateUsageRecord.md b/docs/app_store/UpdateUsageRecord.md
new file mode 100644
index 00000000..094ddb6f
--- /dev/null
+++ b/docs/app_store/UpdateUsageRecord.md
@@ -0,0 +1,17 @@
+# XeroRuby::AppStore::UpdateUsageRecord
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**quantity** | **Integer** | The new quantity for the usage record. Must be a whole number that is greater than or equal to 0 | 
+
+## Code Sample
+
+```ruby
+require 'XeroRuby::AppStore'
+
+instance = XeroRuby::AppStore::UpdateUsageRecord.new(quantity: null)
+```
+
+
diff --git a/docs/app_store/UsageRecord.md b/docs/app_store/UsageRecord.md
new file mode 100644
index 00000000..8a31f325
--- /dev/null
+++ b/docs/app_store/UsageRecord.md
@@ -0,0 +1,31 @@
+# XeroRuby::AppStore::UsageRecord
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**quantity** | **Integer** | The quantity recorded | 
+**subscription_id** | **String** | The unique identifier of the Subscription. | 
+**subscription_item_id** | **String** | The unique identifier of the SubscriptionItem. | 
+**test_mode** | **Boolean** | If the subscription is a test subscription | 
+**recorded_at** | **DateTime** | The time when this usage was recorded in UTC | 
+**usage_record_id** | **String** | The unique identifier of the usageRecord. | 
+**price_per_unit** | **Float** | The price per unit | 
+**product_id** | **String** | The unique identifier of the linked Product | 
+
+## Code Sample
+
+```ruby
+require 'XeroRuby::AppStore'
+
+instance = XeroRuby::AppStore::UsageRecord.new(quantity: null,
+                                 subscription_id: null,
+                                 subscription_item_id: null,
+                                 test_mode: null,
+                                 recorded_at: null,
+                                 usage_record_id: null,
+                                 price_per_unit: null,
+                                 product_id: null)
+```
+
+
diff --git a/docs/app_store/UsageRecordsList.md b/docs/app_store/UsageRecordsList.md
new file mode 100644
index 00000000..9d80bd0d
--- /dev/null
+++ b/docs/app_store/UsageRecordsList.md
@@ -0,0 +1,17 @@
+# XeroRuby::AppStore::UsageRecordsList
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**usage_records** | [**Array&lt;UsageRecord&gt;**](UsageRecord.md) | A collection of usage records | 
+
+## Code Sample
+
+```ruby
+require 'XeroRuby::AppStore'
+
+instance = XeroRuby::AppStore::UsageRecordsList.new(usage_records: null)
+```
+
+
diff --git a/docs/app_store/index.html b/docs/app_store/index.html
index c0e7b1a8..12c7593e 100644
--- a/docs/app_store/index.html
+++ b/docs/app_store/index.html
@@ -862,6 +862,24 @@
     <script>
       // Script section to load models into a JS Var
       var defs = {}
+      defs["CreateUsageRecord"] = {
+  "title" : "",
+  "required" : [ "quantity", "timestamp" ],
+  "type" : "object",
+  "properties" : {
+    "quantity" : {
+      "type" : "integer",
+      "description" : "The initial quantity for the usage record. Must be a whole number that is greater than or equal to 0",
+      "format" : "int32"
+    },
+    "timestamp" : {
+      "type" : "string",
+      "description" : "DateTime in UTC of when the the product was consumed/used",
+      "format" : "date-time"
+    }
+  },
+  "description" : "Data transfer object for public create usage end point"
+};
       defs["Plan"] = {
   "title" : "",
   "required" : [ "id", "name", "status", "subscriptionItems" ],
@@ -1058,6 +1076,81 @@
   },
   "description" : ""
 };
+      defs["UpdateUsageRecord"] = {
+  "title" : "",
+  "required" : [ "quantity" ],
+  "type" : "object",
+  "properties" : {
+    "quantity" : {
+      "type" : "integer",
+      "description" : "The new quantity for the usage record. Must be a whole number that is greater than or equal to 0",
+      "format" : "int32"
+    }
+  },
+  "description" : "Data transfer object for public update usage end point"
+};
+      defs["UsageRecord"] = {
+  "title" : "",
+  "required" : [ "pricePerUnit", "productId", "quantity", "recordedAt", "subscriptionId", "subscriptionItemId", "testMode", "usageRecordId" ],
+  "type" : "object",
+  "properties" : {
+    "quantity" : {
+      "type" : "integer",
+      "description" : "The quantity recorded",
+      "format" : "int32"
+    },
+    "subscriptionId" : {
+      "type" : "string",
+      "description" : "The unique identifier of the Subscription.",
+      "format" : "guid"
+    },
+    "subscriptionItemId" : {
+      "type" : "string",
+      "description" : "The unique identifier of the SubscriptionItem.",
+      "format" : "guid"
+    },
+    "testMode" : {
+      "type" : "boolean",
+      "description" : "If the subscription is a test subscription"
+    },
+    "recordedAt" : {
+      "type" : "string",
+      "description" : "The time when this usage was recorded in UTC",
+      "format" : "date-time"
+    },
+    "usageRecordId" : {
+      "type" : "string",
+      "description" : "The unique identifier of the usageRecord.",
+      "format" : "guid"
+    },
+    "pricePerUnit" : {
+      "type" : "number",
+      "description" : "The price per unit",
+      "format" : "decimal"
+    },
+    "productId" : {
+      "type" : "string",
+      "description" : "The unique identifier of the linked Product",
+      "format" : "guid"
+    }
+  },
+  "description" : ""
+};
+      defs["UsageRecordsList"] = {
+  "title" : "",
+  "required" : [ "usageRecords" ],
+  "type" : "object",
+  "properties" : {
+    "usageRecords" : {
+      "type" : "array",
+      "description" : "A collection of usage records",
+      "items" : {
+        "$ref" : "#/components/schemas/UsageRecord"
+      }
+    }
+  },
+  "description" : "Response to get usage record"
+};
       
       var errs = {};
       
@@ -1141,11 +1234,20 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="AppStore"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="AppStore"><strong>VSN: </strong>3.14.0</li>
+              <li class="nav-header" data-group="AppStore"><strong>VSN: </strong>3.15.0</li>
               <li class="nav-header" data-group="AppStore"><a href="#api-AppStore">Methods</a></li>
               <li data-group="AppStore" data-name="getSubscription" class="">
                 <a href="#api-AppStore-getSubscription">getSubscription</a>
               </li>
+              <li data-group="AppStore" data-name="getUsageRecords" class="">
+                <a href="#api-AppStore-getUsageRecords">getUsageRecords</a>
+              </li>
+              <li data-group="AppStore" data-name="postUsageRecords" class="">
+                <a href="#api-AppStore-postUsageRecords">postUsageRecords</a>
+              </li>
+              <li data-group="AppStore" data-name="putUsageRecords" class="">
+                <a href="#api-AppStore-putUsageRecords">putUsageRecords</a>
+              </li>
             </ul>
           </nav>
         </div>
@@ -1246,6 +1348,407 @@ <h2>Parameters</h2>
                 </article>
               </div>
               <hr>
+              <div id="api-AppStore-getUsageRecords">
+                <article id="api-AppStore-getUsageRecords-0" data-group="User" data-name="getUsageRecords" data-version="0">
+                  <div class="pull-left">
+                    <h1>getUsageRecords</h1>
+                    <p>Gets all usage records related to the subscription</p>
+                  </div>
+                  <div class="pull-right"></div>
+                  <div class="clearfix"></div>
+                  <p></p>
+                  <p class="marked"></p>
+                  <p></p>
+                  <br />
+                  <pre class="prettyprint language-html prettyprinted" data-type="get"><code><span class="pln">/subscriptions/{subscriptionId}/usage-records</span></code></pre>
+                  <p>
+                  <h3>Usage and SDK Samples</h3>
+                  </p>
+                  <ul class="nav nav-tabs nav-tabs-examples">
+                    <!-- *****REPLACE***** comment out the other languages <li> -->
+                    <li class=""><a href="#examples-AppStore-getUsageRecords-0-ruby">Ruby</a></li>
+                  </ul>
+                  <div class="tab-content">
+                    <!-- *****REPLACE***** comment out the other languages tab-pane -->
+                    <div class="tab-pane" id="examples-AppStore-getUsageRecords-0-ruby">
+                      <pre class="prettyprint"><code class="language-ruby">xero_client.set_token_set(user.token_set)
+
+subscription_id = '00000000-0000-0000-0000-000000000000'
+
+begin
+  response = xero_client.accounting_api.get_usage_records(subscription_id)
+  return response
+rescue XeroRuby::ApiError => e
+  puts "Exception when calling get_usage_records: #{e}"
+end
+</code></pre>
+                    </div>
+                  </div>
+                  <h2>Scopes</h2>
+                  <table>
+                    
+                    <tr>
+                      <td>marketplace.billing</td>
+                      <td>Grant read-only access to fixed assets</td>
+                    </tr>
+                    
+                  </table>
+                  <h2>Parameters</h2>
+                  <div class="methodsubtabletitle">Path parameters</div>
+                  <table id="methodsubtable">
+                    <tr>
+                      <th width="150px">Name</th>
+                      <th>Description</th>
+                    </tr>
+                    <tr><td style="width:150px;">subscriptionId<span style="color:red;">*</span></td>
+<td>
+
+
+    <div id="d2e199_getUsageRecords_subscriptionId">
+        <div class="json-schema-view">
+            <div class="primitive">
+                <span class="type">
+                    UUID
+                </span>
+                    <span class="format">
+                        (uuid)
+                    </span>
+
+                    <div class="inner description marked">
+Unique identifier for Subscription object
+                    </div>
+            </div>
+                <div class="inner required">
+                    Required
+                </div>
+        </div>
+    </div>
+</td>
+</tr>
+
+                  </table>
+                </article>
+              </div>
+              <hr>
+              <div id="api-AppStore-postUsageRecords">
+                <article id="api-AppStore-postUsageRecords-0" data-group="User" data-name="postUsageRecords" data-version="0">
+                  <div class="pull-left">
+                    <h1>postUsageRecords</h1>
+                    <p>Send metered usage belonging to this subscription and subscription item</p>
+                  </div>
+                  <div class="pull-right"></div>
+                  <div class="clearfix"></div>
+                  <p></p>
+                  <p class="marked"></p>
+                  <p></p>
+                  <br />
+                  <pre class="prettyprint language-html prettyprinted" data-type="post"><code><span class="pln">/subscriptions/{subscriptionId}/items/{subscriptionItemId}/usage-records</span></code></pre>
+                  <p>
+                  <h3>Usage and SDK Samples</h3>
+                  </p>
+                  <ul class="nav nav-tabs nav-tabs-examples">
+                    <!-- *****REPLACE***** comment out the other languages <li> -->
+                    <li class=""><a href="#examples-AppStore-postUsageRecords-0-ruby">Ruby</a></li>
+                  </ul>
+                  <div class="tab-content">
+                    <!-- *****REPLACE***** comment out the other languages tab-pane -->
+                    <div class="tab-pane" id="examples-AppStore-postUsageRecords-0-ruby">
+                      <pre class="prettyprint"><code class="language-ruby">xero_client.set_token_set(user.token_set)
+
+subscription_id = '00000000-0000-0000-0000-000000000000'
+subscription_item_id = '00000000-0000-0000-0000-000000000000'
+
+begin
+  response = xero_client.accounting_api.post_usage_records(subscription_id, subscription_item_id, createUsageRecord)
+  return response
+rescue XeroRuby::ApiError => e
+  puts "Exception when calling post_usage_records: #{e}"
+end
+</code></pre>
+                    </div>
+                  </div>
+                  <h2>Scopes</h2>
+                  <table>
+                    
+                    <tr>
+                      <td>marketplace.billing</td>
+                      <td>Grant read-only access to fixed assets</td>
+                    </tr>
+                    
+                  </table>
+                  <h2>Parameters</h2>
+                  <div class="methodsubtabletitle">Path parameters</div>
+                  <table id="methodsubtable">
+                    <tr>
+                      <th width="150px">Name</th>
+                      <th>Description</th>
+                    </tr>
+                    <tr><td style="width:150px;">subscriptionId<span style="color:red;">*</span></td>
+<td>
+
+
+    <div id="d2e199_postUsageRecords_subscriptionId">
+        <div class="json-schema-view">
+            <div class="primitive">
+                <span class="type">
+                    UUID
+                </span>
+                    <span class="format">
+                        (uuid)
+                    </span>
+
+                    <div class="inner description marked">
+Unique identifier for Subscription object
+                    </div>
+            </div>
+                <div class="inner required">
+                    Required
+                </div>
+        </div>
+    </div>
+</td>
+</tr>
+
+                    <tr><td style="width:150px;">subscriptionItemId<span style="color:red;">*</span></td>
+<td>
+
+
+    <div id="d2e199_postUsageRecords_subscriptionItemId">
+        <div class="json-schema-view">
+            <div class="primitive">
+                <span class="type">
+                    UUID
+                </span>
+                    <span class="format">
+                        (uuid)
+                    </span>
+
+                    <div class="inner description marked">
+The unique identifier of the subscriptionItem
+                    </div>
+            </div>
+                <div class="inner required">
+                    Required
+                </div>
+        </div>
+    </div>
+</td>
+</tr>
+
+                  </table>
+                  <div class="methodsubtabletitle">Body parameters</div>
+                  <table id="methodsubtable">
+                    <tr>
+                      <th width="150px">Name</th>
+                      <th>Description</th>
+                    </tr>
+                    <tr>
+  <td style="width:150px;">createUsageRecord <span style="color:red;">*</span></td>
+  <td>
+    <div class="json-schema-view">
+      <div class="primitive">
+        <span class="type">
+        CreateUsageRecord
+        </span>
+        <div class="inner description marked">
+          Contains the quantity for the usage record to create
+        </div>
+      </div>
+      <div class="inner required">
+        Required
+      </div>
+    </div>
+    <script type="application/ld+json">
+      {
+  "description" : "Contains the quantity for the usage record to create",
+  "content" : {
+    "application/json" : {
+      "schema" : {
+        "$ref" : "#/components/schemas/CreateUsageRecord"
+      },
+      "example" : "{ \"timestamp\": \"2022-01-21T13:01:00Z\", \"quantity\": 10 }"
+    }
+  },
+  "required" : true
+}
+    </script>
+                  </table>
+                </article>
+              </div>
+              <hr>
+              <div id="api-AppStore-putUsageRecords">
+                <article id="api-AppStore-putUsageRecords-0" data-group="User" data-name="putUsageRecords" data-version="0">
+                  <div class="pull-left">
+                    <h1>putUsageRecords</h1>
+                    <p>Update and existing metered usage belonging to this subscription and subscription item</p>
+                  </div>
+                  <div class="pull-right"></div>
+                  <div class="clearfix"></div>
+                  <p></p>
+                  <p class="marked"></p>
+                  <p></p>
+                  <br />
+                  <pre class="prettyprint language-html prettyprinted" data-type="put"><code><span class="pln">/subscriptions/{subscriptionId}/items/{subscriptionItemId}/usage-records/{usageRecordId}</span></code></pre>
+                  <p>
+                  <h3>Usage and SDK Samples</h3>
+                  </p>
+                  <ul class="nav nav-tabs nav-tabs-examples">
+                    <!-- *****REPLACE***** comment out the other languages <li> -->
+                    <li class=""><a href="#examples-AppStore-putUsageRecords-0-ruby">Ruby</a></li>
+                  </ul>
+                  <div class="tab-content">
+                    <!-- *****REPLACE***** comment out the other languages tab-pane -->
+                    <div class="tab-pane" id="examples-AppStore-putUsageRecords-0-ruby">
+                      <pre class="prettyprint"><code class="language-ruby">xero_client.set_token_set(user.token_set)
+
+subscription_id = '00000000-0000-0000-0000-000000000000'
+subscription_item_id = '00000000-0000-0000-0000-000000000000'
+usage_record_id = '00000000-0000-0000-0000-000000000000'
+
+begin
+  response = xero_client.accounting_api.put_usage_records(subscription_id, subscription_item_id, usage_record_id, updateUsageRecord)
+  return response
+rescue XeroRuby::ApiError => e
+  puts "Exception when calling put_usage_records: #{e}"
+end
+</code></pre>
+                    </div>
+                  </div>
+                  <h2>Scopes</h2>
+                  <table>
+                    
+                    <tr>
+                      <td>marketplace.billing</td>
+                      <td>Grant read-only access to fixed assets</td>
+                    </tr>
+                    
+                  </table>
+                  <h2>Parameters</h2>
+                  <div class="methodsubtabletitle">Path parameters</div>
+                  <table id="methodsubtable">
+                    <tr>
+                      <th width="150px">Name</th>
+                      <th>Description</th>
+                    </tr>
+                    <tr><td style="width:150px;">subscriptionId<span style="color:red;">*</span></td>
+<td>
+
+
+    <div id="d2e199_putUsageRecords_subscriptionId">
+        <div class="json-schema-view">
+            <div class="primitive">
+                <span class="type">
+                    UUID
+                </span>
+                    <span class="format">
+                        (uuid)
+                    </span>
+
+                    <div class="inner description marked">
+Unique identifier for Subscription object
+                    </div>
+            </div>
+                <div class="inner required">
+                    Required
+                </div>
+        </div>
+    </div>
+</td>
+</tr>
+
+                    <tr><td style="width:150px;">subscriptionItemId<span style="color:red;">*</span></td>
+<td>
+
+
+    <div id="d2e199_putUsageRecords_subscriptionItemId">
+        <div class="json-schema-view">
+            <div class="primitive">
+                <span class="type">
+                    UUID
+                </span>
+                    <span class="format">
+                        (uuid)
+                    </span>
+
+                    <div class="inner description marked">
+The unique identifier of the subscriptionItem
+                    </div>
+            </div>
+                <div class="inner required">
+                    Required
+                </div>
+        </div>
+    </div>
+</td>
+</tr>
+
+                    <tr><td style="width:150px;">usageRecordId<span style="color:red;">*</span></td>
+<td>
+
+
+    <div id="d2e199_putUsageRecords_usageRecordId">
+        <div class="json-schema-view">
+            <div class="primitive">
+                <span class="type">
+                    UUID
+                </span>
+                    <span class="format">
+                        (uuid)
+                    </span>
+
+                    <div class="inner description marked">
+The unique identifier of the usage record
+                    </div>
+            </div>
+                <div class="inner required">
+                    Required
+                </div>
+        </div>
+    </div>
+</td>
+</tr>
+
+                  </table>
+                  <div class="methodsubtabletitle">Body parameters</div>
+                  <table id="methodsubtable">
+                    <tr>
+                      <th width="150px">Name</th>
+                      <th>Description</th>
+                    </tr>
+                    <tr>
+  <td style="width:150px;">updateUsageRecord <span style="color:red;">*</span></td>
+  <td>
+    <div class="json-schema-view">
+      <div class="primitive">
+        <span class="type">
+        UpdateUsageRecord
+        </span>
+        <div class="inner description marked">
+          Contains the quantity for the usage record to update
+        </div>
+      </div>
+      <div class="inner required">
+        Required
+      </div>
+    </div>
+    <script type="application/ld+json">
+      {
+  "description" : "Contains the quantity for the usage record to update",
+  "content" : {
+    "application/json" : {
+      "schema" : {
+        "$ref" : "#/components/schemas/UpdateUsageRecord"
+      },
+      "example" : "{ \"quantity\": 10 }"
+    }
+  },
+  "required" : true
+}
+    </script>
+                  </table>
+                </article>
+              </div>
+              <hr>
             </section>
           </div>
           <div id="footer">
diff --git a/docs/assets/index.html b/docs/assets/index.html
index 9960f9bf..8825c7d8 100644
--- a/docs/assets/index.html
+++ b/docs/assets/index.html
@@ -1392,7 +1392,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="Asset"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="Asset"><strong>VSN: </strong>3.14.0</li>
+              <li class="nav-header" data-group="Asset"><strong>VSN: </strong>3.15.0</li>
               <li class="nav-header" data-group="Asset"><a href="#api-Asset">Methods</a></li>
               <li data-group="Asset" data-name="createAsset" class="">
                 <a href="#api-Asset-createAsset">createAsset</a>
diff --git a/docs/files/index.html b/docs/files/index.html
index dec9b846..c31b56d0 100644
--- a/docs/files/index.html
+++ b/docs/files/index.html
@@ -1155,7 +1155,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="Files"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="Files"><strong>VSN: </strong>3.14.0</li>
+              <li class="nav-header" data-group="Files"><strong>VSN: </strong>3.15.0</li>
               <li class="nav-header" data-group="Files"><a href="#api-Files">Methods</a></li>
               <li data-group="Files" data-name="createFileAssociation" class="">
                 <a href="#api-Files-createFileAssociation">createFileAssociation</a>
diff --git a/docs/finance/index.html b/docs/finance/index.html
index d2c78027..21cf4da7 100644
--- a/docs/finance/index.html
+++ b/docs/finance/index.html
@@ -2718,7 +2718,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="Finance"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="Finance"><strong>VSN: </strong>3.14.0</li>
+              <li class="nav-header" data-group="Finance"><strong>VSN: </strong>3.15.0</li>
               <li class="nav-header" data-group="Finance"><a href="#api-Finance">Methods</a></li>
               <li data-group="Finance" data-name="getAccountingActivityAccountUsage" class="">
                 <a href="#api-Finance-getAccountingActivityAccountUsage">getAccountingActivityAccountUsage</a>
diff --git a/docs/payroll_au/index.html b/docs/payroll_au/index.html
index 02fcf1a4..b4f7b734 100644
--- a/docs/payroll_au/index.html
+++ b/docs/payroll_au/index.html
@@ -3344,7 +3344,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="PayrollAu"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="PayrollAu"><strong>VSN: </strong>3.14.0</li>
+              <li class="nav-header" data-group="PayrollAu"><strong>VSN: </strong>3.15.0</li>
               <li class="nav-header" data-group="PayrollAu"><a href="#api-PayrollAu">Methods</a></li>
               <li data-group="PayrollAu" data-name="createEmployee" class="">
                 <a href="#api-PayrollAu-createEmployee">createEmployee</a>
diff --git a/docs/payroll_nz/index.html b/docs/payroll_nz/index.html
index 1ffdc013..693632d0 100644
--- a/docs/payroll_nz/index.html
+++ b/docs/payroll_nz/index.html
@@ -3838,7 +3838,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="PayrollNz"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="PayrollNz"><strong>VSN: </strong>3.14.0</li>
+              <li class="nav-header" data-group="PayrollNz"><strong>VSN: </strong>3.15.0</li>
               <li class="nav-header" data-group="PayrollNz"><a href="#api-PayrollNz">Methods</a></li>
               <li data-group="PayrollNz" data-name="approveTimesheet" class="">
                 <a href="#api-PayrollNz-approveTimesheet">approveTimesheet</a>
diff --git a/docs/payroll_uk/index.html b/docs/payroll_uk/index.html
index 6bfc600b..f3cda025 100644
--- a/docs/payroll_uk/index.html
+++ b/docs/payroll_uk/index.html
@@ -3510,7 +3510,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="PayrollUk"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="PayrollUk"><strong>VSN: </strong>3.14.0</li>
+              <li class="nav-header" data-group="PayrollUk"><strong>VSN: </strong>3.15.0</li>
               <li class="nav-header" data-group="PayrollUk"><a href="#api-PayrollUk">Methods</a></li>
               <li data-group="PayrollUk" data-name="approveTimesheet" class="">
                 <a href="#api-PayrollUk-approveTimesheet">approveTimesheet</a>
diff --git a/docs/projects/index.html b/docs/projects/index.html
index 88014e98..83989b5b 100644
--- a/docs/projects/index.html
+++ b/docs/projects/index.html
@@ -1462,7 +1462,7 @@
           <nav id="scrollingNav">
             <ul class="sidenav nav nav-list">
               <li class="nav-header" data-group="Project"><strong>SDK: </strong><span id='sdk-name'></span></li>
-              <li class="nav-header" data-group="Project"><strong>VSN: </strong>3.14.0</li>
+              <li class="nav-header" data-group="Project"><strong>VSN: </strong>3.15.0</li>
               <li class="nav-header" data-group="Project"><a href="#api-Project">Methods</a></li>
               <li data-group="Project" data-name="createProject" class="">
                 <a href="#api-Project-createProject">createProject</a>
diff --git a/lib/xero-ruby.rb b/lib/xero-ruby.rb
index f078ee03..0149df47 100644
--- a/lib/xero-ruby.rb
+++ b/lib/xero-ruby.rb
@@ -72,12 +72,16 @@
 require 'xero-ruby/models/finance/trial_balance_response'
 require 'xero-ruby/models/finance/user_activities_response'
 require 'xero-ruby/models/finance/user_response'
+require 'xero-ruby/models/app_store/create_usage_record'
 require 'xero-ruby/models/app_store/plan'
 require 'xero-ruby/models/app_store/price'
 require 'xero-ruby/models/app_store/problem_details'
 require 'xero-ruby/models/app_store/product'
 require 'xero-ruby/models/app_store/subscription'
 require 'xero-ruby/models/app_store/subscription_item'
+require 'xero-ruby/models/app_store/update_usage_record'
+require 'xero-ruby/models/app_store/usage_record'
+require 'xero-ruby/models/app_store/usage_records_list'
 require 'xero-ruby/models/payroll_uk/account'
 require 'xero-ruby/models/payroll_uk/accounts'
 require 'xero-ruby/models/payroll_uk/address'
diff --git a/lib/xero-ruby/api/app_store_api.rb b/lib/xero-ruby/api/app_store_api.rb
index da928f6d..37588ea8 100644
--- a/lib/xero-ruby/api/app_store_api.rb
+++ b/lib/xero-ruby/api/app_store_api.rb
@@ -83,5 +83,243 @@ def get_subscription_with_http_info(subscription_id, options = {})
       end
       return data, status_code, headers
     end
+
+    # Gets all usage records related to the subscription
+    # @param subscription_id [String] Unique identifier for Subscription object
+    # @param [Hash] opts the optional parameters
+    # @return [UsageRecordsList]
+    def get_usage_records(subscription_id, opts = {})
+      data, _status_code, _headers = get_usage_records_with_http_info(subscription_id, opts)
+      data
+    end
+
+    # Gets all usage records related to the subscription
+    # @param subscription_id [String] Unique identifier for Subscription object
+    # @param [Hash] opts the optional parameters
+    # @return [Array<(UsageRecordsList, Integer, Hash)>] UsageRecordsList data, response status code and response headers
+    def get_usage_records_with_http_info(subscription_id, options = {})
+      opts = options.dup
+      if @api_client.config.debugging
+        @api_client.config.logger.debug 'Calling API: AppStoreApi.get_usage_records ...'
+      end
+      # verify the required parameter 'subscription_id' is set
+      if @api_client.config.client_side_validation && subscription_id.nil?
+        fail ArgumentError, "Missing the required parameter 'subscription_id' when calling AppStoreApi.get_usage_records"
+      end
+      # resource path
+      local_var_path = '/subscriptions/{subscriptionId}/usage-records'.sub('{' + 'subscriptionId' + '}', subscription_id.to_s)
+
+      # camelize keys of incoming `where` opts
+      opts[:'where'] = @api_client.parameterize_where(opts[:'where']) if !opts[:'where'].nil?
+
+      # query parameters
+      query_params = opts[:query_params] || {}
+      
+      # XeroAPI's `IDs` convention openapi-generator does not snake_case properly.. manual over-riding `i_ds` malformations:
+      query_params[:'IDs'] = @api_client.build_collection_param(opts[:'ids'], :csv) if !opts[:'ids'].nil?
+      query_params[:'ContactIDs'] = @api_client.build_collection_param(opts[:'contact_ids'], :csv) if !opts[:'contact_ids'].nil?
+
+      # header parameters
+      header_params = opts[:header_params] || {}
+      # HTTP header 'Accept' (if needed)
+      header_params['Accept'] = @api_client.select_header_accept(['application/json'])
+
+      # form parameters
+      form_params = opts[:form_params] || {}
+
+      # http body (model)
+      post_body = opts[:body] 
+
+      # return_type
+      return_type = opts[:return_type] || 'UsageRecordsList' 
+
+      # auth_names
+      auth_names = opts[:auth_names] || ['OAuth2']
+
+      new_options = opts.merge(
+        :header_params => header_params,
+        :query_params => query_params,
+        :form_params => form_params,
+        :body => post_body,
+        :auth_names => auth_names,
+        :return_type => return_type
+      )
+
+      data, status_code, headers = @api_client.call_api(:GET, local_var_path, "AppStoreApi", new_options)
+      if @api_client.config.debugging
+        @api_client.config.logger.debug "API called: AppStoreApi#get_usage_records\nData: #{data.inspect}\nStatus code: #{status_code}\nHeaders: #{headers}"
+      end
+      return data, status_code, headers
+    end
+
+    # Send metered usage belonging to this subscription and subscription item
+    # @param subscription_id [String] Unique identifier for Subscription object
+    # @param subscription_item_id [String] The unique identifier of the subscriptionItem
+    # @param create_usage_record [CreateUsageRecord] Contains the quantity for the usage record to create
+    # @param [Hash] opts the optional parameters
+    # @return [UsageRecord]
+    def post_usage_records(subscription_id, subscription_item_id, create_usage_record, opts = {})
+      data, _status_code, _headers = post_usage_records_with_http_info(subscription_id, subscription_item_id, create_usage_record, opts)
+      data
+    end
+
+    # Send metered usage belonging to this subscription and subscription item
+    # @param subscription_id [String] Unique identifier for Subscription object
+    # @param subscription_item_id [String] The unique identifier of the subscriptionItem
+    # @param create_usage_record [CreateUsageRecord] Contains the quantity for the usage record to create
+    # @param [Hash] opts the optional parameters
+    # @return [Array<(UsageRecord, Integer, Hash)>] UsageRecord data, response status code and response headers
+    def post_usage_records_with_http_info(subscription_id, subscription_item_id, create_usage_record, options = {})
+      opts = options.dup
+      if @api_client.config.debugging
+        @api_client.config.logger.debug 'Calling API: AppStoreApi.post_usage_records ...'
+      end
+      # verify the required parameter 'subscription_id' is set
+      if @api_client.config.client_side_validation && subscription_id.nil?
+        fail ArgumentError, "Missing the required parameter 'subscription_id' when calling AppStoreApi.post_usage_records"
+      end
+      # verify the required parameter 'subscription_item_id' is set
+      if @api_client.config.client_side_validation && subscription_item_id.nil?
+        fail ArgumentError, "Missing the required parameter 'subscription_item_id' when calling AppStoreApi.post_usage_records"
+      end
+      # verify the required parameter 'create_usage_record' is set
+      if @api_client.config.client_side_validation && create_usage_record.nil?
+        fail ArgumentError, "Missing the required parameter 'create_usage_record' when calling AppStoreApi.post_usage_records"
+      end
+      # resource path
+      local_var_path = '/subscriptions/{subscriptionId}/items/{subscriptionItemId}/usage-records'.sub('{' + 'subscriptionId' + '}', subscription_id.to_s).sub('{' + 'subscriptionItemId' + '}', subscription_item_id.to_s)
+
+      # camelize keys of incoming `where` opts
+      opts[:'where'] = @api_client.parameterize_where(opts[:'where']) if !opts[:'where'].nil?
+
+      # query parameters
+      query_params = opts[:query_params] || {}
+      
+      # XeroAPI's `IDs` convention openapi-generator does not snake_case properly.. manual over-riding `i_ds` malformations:
+      query_params[:'IDs'] = @api_client.build_collection_param(opts[:'ids'], :csv) if !opts[:'ids'].nil?
+      query_params[:'ContactIDs'] = @api_client.build_collection_param(opts[:'contact_ids'], :csv) if !opts[:'contact_ids'].nil?
+
+      # header parameters
+      header_params = opts[:header_params] || {}
+      # HTTP header 'Accept' (if needed)
+      header_params['Accept'] = @api_client.select_header_accept(['application/json'])
+      # HTTP header 'Content-Type'
+      header_params['Content-Type'] = @api_client.select_header_content_type(['application/json'])
+
+      # form parameters
+      form_params = opts[:form_params] || {}
+
+      # http body (model)
+      post_body = opts[:body] || @api_client.object_to_http_body(create_usage_record) 
+
+      # return_type
+      return_type = opts[:return_type] || 'UsageRecord' 
+
+      # auth_names
+      auth_names = opts[:auth_names] || ['OAuth2']
+
+      new_options = opts.merge(
+        :header_params => header_params,
+        :query_params => query_params,
+        :form_params => form_params,
+        :body => post_body,
+        :auth_names => auth_names,
+        :return_type => return_type
+      )
+
+      data, status_code, headers = @api_client.call_api(:POST, local_var_path, "AppStoreApi", new_options)
+      if @api_client.config.debugging
+        @api_client.config.logger.debug "API called: AppStoreApi#post_usage_records\nData: #{data.inspect}\nStatus code: #{status_code}\nHeaders: #{headers}"
+      end
+      return data, status_code, headers
+    end
+
+    # Update and existing metered usage belonging to this subscription and subscription item
+    # @param subscription_id [String] Unique identifier for Subscription object
+    # @param subscription_item_id [String] The unique identifier of the subscriptionItem
+    # @param usage_record_id [String] The unique identifier of the usage record
+    # @param update_usage_record [UpdateUsageRecord] Contains the quantity for the usage record to update
+    # @param [Hash] opts the optional parameters
+    # @return [UsageRecord]
+    def put_usage_records(subscription_id, subscription_item_id, usage_record_id, update_usage_record, opts = {})
+      data, _status_code, _headers = put_usage_records_with_http_info(subscription_id, subscription_item_id, usage_record_id, update_usage_record, opts)
+      data
+    end
+
+    # Update and existing metered usage belonging to this subscription and subscription item
+    # @param subscription_id [String] Unique identifier for Subscription object
+    # @param subscription_item_id [String] The unique identifier of the subscriptionItem
+    # @param usage_record_id [String] The unique identifier of the usage record
+    # @param update_usage_record [UpdateUsageRecord] Contains the quantity for the usage record to update
+    # @param [Hash] opts the optional parameters
+    # @return [Array<(UsageRecord, Integer, Hash)>] UsageRecord data, response status code and response headers
+    def put_usage_records_with_http_info(subscription_id, subscription_item_id, usage_record_id, update_usage_record, options = {})
+      opts = options.dup
+      if @api_client.config.debugging
+        @api_client.config.logger.debug 'Calling API: AppStoreApi.put_usage_records ...'
+      end
+      # verify the required parameter 'subscription_id' is set
+      if @api_client.config.client_side_validation && subscription_id.nil?
+        fail ArgumentError, "Missing the required parameter 'subscription_id' when calling AppStoreApi.put_usage_records"
+      end
+      # verify the required parameter 'subscription_item_id' is set
+      if @api_client.config.client_side_validation && subscription_item_id.nil?
+        fail ArgumentError, "Missing the required parameter 'subscription_item_id' when calling AppStoreApi.put_usage_records"
+      end
+      # verify the required parameter 'usage_record_id' is set
+      if @api_client.config.client_side_validation && usage_record_id.nil?
+        fail ArgumentError, "Missing the required parameter 'usage_record_id' when calling AppStoreApi.put_usage_records"
+      end
+      # verify the required parameter 'update_usage_record' is set
+      if @api_client.config.client_side_validation && update_usage_record.nil?
+        fail ArgumentError, "Missing the required parameter 'update_usage_record' when calling AppStoreApi.put_usage_records"
+      end
+      # resource path
+      local_var_path = '/subscriptions/{subscriptionId}/items/{subscriptionItemId}/usage-records/{usageRecordId}'.sub('{' + 'subscriptionId' + '}', subscription_id.to_s).sub('{' + 'subscriptionItemId' + '}', subscription_item_id.to_s).sub('{' + 'usageRecordId' + '}', usage_record_id.to_s)
+
+      # camelize keys of incoming `where` opts
+      opts[:'where'] = @api_client.parameterize_where(opts[:'where']) if !opts[:'where'].nil?
+
+      # query parameters
+      query_params = opts[:query_params] || {}
+      
+      # XeroAPI's `IDs` convention openapi-generator does not snake_case properly.. manual over-riding `i_ds` malformations:
+      query_params[:'IDs'] = @api_client.build_collection_param(opts[:'ids'], :csv) if !opts[:'ids'].nil?
+      query_params[:'ContactIDs'] = @api_client.build_collection_param(opts[:'contact_ids'], :csv) if !opts[:'contact_ids'].nil?
+
+      # header parameters
+      header_params = opts[:header_params] || {}
+      # HTTP header 'Accept' (if needed)
+      header_params['Accept'] = @api_client.select_header_accept(['application/json'])
+      # HTTP header 'Content-Type'
+      header_params['Content-Type'] = @api_client.select_header_content_type(['application/json'])
+
+      # form parameters
+      form_params = opts[:form_params] || {}
+
+      # http body (model)
+      post_body = opts[:body] || @api_client.object_to_http_body(update_usage_record) 
+
+      # return_type
+      return_type = opts[:return_type] || 'UsageRecord' 
+
+      # auth_names
+      auth_names = opts[:auth_names] || ['OAuth2']
+
+      new_options = opts.merge(
+        :header_params => header_params,
+        :query_params => query_params,
+        :form_params => form_params,
+        :body => post_body,
+        :auth_names => auth_names,
+        :return_type => return_type
+      )
+
+      data, status_code, headers = @api_client.call_api(:PUT, local_var_path, "AppStoreApi", new_options)
+      if @api_client.config.debugging
+        @api_client.config.logger.debug "API called: AppStoreApi#put_usage_records\nData: #{data.inspect}\nStatus code: #{status_code}\nHeaders: #{headers}"
+      end
+      return data, status_code, headers
+    end
   end
 end
diff --git a/lib/xero-ruby/models/accounting/line_item.rb b/lib/xero-ruby/models/accounting/line_item.rb
index 0fe16318..e86407cf 100644
--- a/lib/xero-ruby/models/accounting/line_item.rb
+++ b/lib/xero-ruby/models/accounting/line_item.rb
@@ -46,7 +46,7 @@ class LineItem
 
     attr_accessor :item
     
-    # If you wish to omit either of the <Quantity> or <UnitAmount> you can provide a LineAmount and Xero will calculate the missing amount for you. The line amount reflects the discounted price if a DiscountRate has been used . i.e LineAmount = Quantity * Unit Amount * ((100 – DiscountRate)/100)
+    # If you wish to omit either the Quantity or UnitAmount you can provide a LineAmount and Xero will calculate the missing amount for you. The line amount reflects the discounted price if either a DiscountRate or DiscountAmount has been used i.e. LineAmount = Quantity * Unit Amount * ((100 - DiscountRate)/100) or LineAmount = (Quantity * UnitAmount) - DiscountAmount
     attr_accessor :line_amount
     
     # Optional Tracking Category – see Tracking.  Any LineItem can have a  maximum of 2 <TrackingCategory> elements.
@@ -55,7 +55,7 @@ class LineItem
     # Percentage discount being applied to a line item (only supported on  ACCREC invoices – ACC PAY invoices and credit notes in Xero do not support discounts
     attr_accessor :discount_rate
     
-    # Discount amount being applied to a line item. Only supported on ACCREC invoices - ACCPAY invoices and credit notes in Xero do not support discounts.
+    # Discount amount being applied to a line item. Only supported on ACCREC invoices and quotes. ACCPAY invoices and credit notes in Xero do not support discounts.
     attr_accessor :discount_amount
     
     # The Xero identifier for a Repeating Invoice
diff --git a/lib/xero-ruby/models/app_store/create_usage_record.rb b/lib/xero-ruby/models/app_store/create_usage_record.rb
new file mode 100644
index 00000000..c30c9348
--- /dev/null
+++ b/lib/xero-ruby/models/app_store/create_usage_record.rb
@@ -0,0 +1,243 @@
+=begin
+#Xero AppStore API
+
+#These endpoints are for Xero Partners to interact with the App Store Billing platform
+
+Contact: api@xero.com
+Generated by: https://openapi-generator.tech
+OpenAPI Generator version: 4.3.1
+
+=end
+
+require 'time'
+require 'date'
+
+module XeroRuby::AppStore
+  # Data transfer object for public create usage end point
+  require 'bigdecimal'
+
+  class CreateUsageRecord
+    # The initial quantity for the usage record. Must be a whole number that is greater than or equal to 0
+    attr_accessor :quantity
+    
+    # DateTime in UTC of when the the product was consumed/used
+    attr_accessor :timestamp
+    
+    # Attribute mapping from ruby-style variable name to JSON key.
+    def self.attribute_map
+      {
+        :'quantity' => :'quantity',
+        :'timestamp' => :'timestamp'
+      }
+    end
+
+    # Attribute type mapping.
+    def self.openapi_types
+      {
+        :'quantity' => :'Integer',
+        :'timestamp' => :'DateTime'
+      }
+    end
+
+    # Initializes the object
+    # @param [Hash] attributes Model attributes in the form of hash
+    def initialize(attributes = {})
+      if (!attributes.is_a?(Hash))
+        fail ArgumentError, "The input argument (attributes) must be a hash in `XeroRuby::AppStore::CreateUsageRecord` initialize method"
+      end
+
+      # check to see if the attribute exists and convert string to symbol for hash key
+      attributes = attributes.each_with_object({}) { |(k, v), h|
+        if (!self.class.attribute_map.key?(k.to_sym))
+          fail ArgumentError, "`#{k}` is not a valid attribute in `XeroRuby::AppStore::CreateUsageRecord`. Please check the name to make sure it's valid. List of attributes: " + self.class.attribute_map.keys.inspect
+        end
+        h[k.to_sym] = v
+      }
+
+      if attributes.key?(:'quantity')
+        self.quantity = attributes[:'quantity']
+      end
+
+      if attributes.key?(:'timestamp')
+        self.timestamp = attributes[:'timestamp']
+      end
+    end
+
+    # Show invalid properties with the reasons. Usually used together with valid?
+    # @return Array for valid properties with the reasons
+    def list_invalid_properties
+      invalid_properties = Array.new
+      if @quantity.nil?
+        invalid_properties.push('invalid value for "quantity", quantity cannot be nil.')
+      end
+
+      if @timestamp.nil?
+        invalid_properties.push('invalid value for "timestamp", timestamp cannot be nil.')
+      end
+
+      invalid_properties
+    end
+
+    # Check to see if the all the properties in the model are valid
+    # @return true if the model is valid
+    def valid?
+      return false if @quantity.nil?
+      return false if @timestamp.nil?
+      true
+    end
+
+    # Checks equality by comparing each attribute.
+    # @param [Object] Object to be compared
+    def ==(o)
+      return true if self.equal?(o)
+      self.class == o.class &&
+          quantity == o.quantity &&
+          timestamp == o.timestamp
+    end
+
+    # @see the `==` method
+    # @param [Object] Object to be compared
+    def eql?(o)
+      self == o
+    end
+
+    # Calculates hash code according to all attributes.
+    # @return [Integer] Hash code
+    def hash
+      [quantity, timestamp].hash
+    end
+
+    # Builds the object from hash
+    # @param [Hash] attributes Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    def self.build_from_hash(attributes)
+      new.build_from_hash(attributes)
+    end
+
+    # Builds the object from hash
+    # @param [Hash] attributes Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    def build_from_hash(attributes)
+      return nil unless attributes.is_a?(Hash)
+      self.class.openapi_types.each_pair do |key, type|
+        if type =~ /\AArray<(.*)>/i
+          # check to ensure the input is an array given that the attribute
+          # is documented as an array but the input is not
+          if attributes[self.class.attribute_map[key]].is_a?(Array)
+            self.send("#{key}=", attributes[self.class.attribute_map[key]].map { |v| _deserialize($1, v) })
+          end
+        elsif !attributes[self.class.attribute_map[key]].nil?
+          self.send("#{key}=", _deserialize(type, attributes[self.class.attribute_map[key]]))
+        end # or else data not found in attributes(hash), not an issue as the data can be optional
+      end
+
+      self
+    end
+
+    # Deserializes the data based on type
+    # @param string type Data type
+    # @param string value Value to be deserialized
+    # @return [Object] Deserialized data
+    def _deserialize(type, value)
+      case type.to_sym
+      when :DateTime
+        DateTime.parse(parse_date(value))
+      when :Date
+        Date.parse(parse_date(value))
+      when :String
+        value.to_s
+      when :Integer
+        value.to_i
+      when :Float
+        value.to_f
+      when :BigDecimal
+        BigDecimal(value.to_s)
+      when :Boolean
+        if value.to_s =~ /\A(true|t|yes|y|1)\z/i
+          true
+        else
+          false
+        end
+      when :Object
+        # generic object (usually a Hash), return directly
+        value
+      when /\AArray<(?<inner_type>.+)>\z/
+        inner_type = Regexp.last_match[:inner_type]
+        value.map { |v| _deserialize(inner_type, v) }
+      when /\AHash<(?<k_type>.+?), (?<v_type>.+)>\z/
+        k_type = Regexp.last_match[:k_type]
+        v_type = Regexp.last_match[:v_type]
+        {}.tap do |hash|
+          value.each do |k, v|
+            hash[_deserialize(k_type, k)] = _deserialize(v_type, v)
+          end
+        end
+      else # model
+        XeroRuby::AppStore.const_get(type).build_from_hash(value)
+      end
+    end
+
+    # Returns the string representation of the object
+    # @return [String] String presentation of the object
+    def to_s
+      to_hash.to_s
+    end
+
+    # to_body is an alias to to_hash (backward compatibility)
+    # @return [Hash] Returns the object in the form of hash
+    def to_body
+      to_hash
+    end
+
+    # Returns the object in the form of hash
+    # @return [Hash] Returns the object in the form of hash
+    def to_hash(downcase: false)
+      hash = {}
+      self.class.attribute_map.each_pair do |attr, param|
+        value = self.send(attr)
+        next if value.nil?
+        key = downcase ? attr : param
+        hash[key] = _to_hash(value, downcase: downcase)
+      end
+      hash
+    end
+
+    # Returns the object in the form of hash with snake_case
+    def to_attributes
+      to_hash(downcase: true)
+    end
+
+    # Outputs non-array value in the form of hash
+    # For object, use to_hash. Otherwise, just return the value
+    # @param [Object] value Any valid value
+    # @return [Hash] Returns the value in the form of hash
+    def _to_hash(value, downcase: false)
+      if value.is_a?(Array)
+        value.map do |v|
+          v.to_hash(downcase: downcase)
+        end
+      elsif value.is_a?(Hash)
+        {}.tap do |hash|
+          value.map { |k, v| hash[k] = _to_hash(v, downcase: downcase) }
+        end
+      elsif value.respond_to? :to_hash
+        value.to_hash(downcase: downcase)
+      else
+        value
+      end
+    end
+
+    def parse_date(datestring)
+      if datestring.include?('Date')
+        date_pattern = /\/Date\((-?\d+)(\+\d+)?\)\//
+        original, date, timezone = *date_pattern.match(datestring)
+        date = (date.to_i / 1000)
+        Time.at(date).utc.strftime('%Y-%m-%dT%H:%M:%S%z').to_s
+      elsif /(\d\d\d\d)-(\d\d)/.match(datestring) # handles dates w/out Days: YYYY-MM*-DD
+        Time.parse(datestring + '-01').strftime('%Y-%m-%dT%H:%M:%S').to_s
+      else # handle date 'types' for small subset of payroll API's
+        Time.parse(datestring).strftime('%Y-%m-%dT%H:%M:%S').to_s
+      end
+    end
+  end
+end
diff --git a/lib/xero-ruby/models/app_store/update_usage_record.rb b/lib/xero-ruby/models/app_store/update_usage_record.rb
new file mode 100644
index 00000000..8bf410ea
--- /dev/null
+++ b/lib/xero-ruby/models/app_store/update_usage_record.rb
@@ -0,0 +1,228 @@
+=begin
+#Xero AppStore API
+
+#These endpoints are for Xero Partners to interact with the App Store Billing platform
+
+Contact: api@xero.com
+Generated by: https://openapi-generator.tech
+OpenAPI Generator version: 4.3.1
+
+=end
+
+require 'time'
+require 'date'
+
+module XeroRuby::AppStore
+  # Data transfer object for public update usage end point
+  require 'bigdecimal'
+
+  class UpdateUsageRecord
+    # The new quantity for the usage record. Must be a whole number that is greater than or equal to 0
+    attr_accessor :quantity
+    
+    # Attribute mapping from ruby-style variable name to JSON key.
+    def self.attribute_map
+      {
+        :'quantity' => :'quantity'
+      }
+    end
+
+    # Attribute type mapping.
+    def self.openapi_types
+      {
+        :'quantity' => :'Integer'
+      }
+    end
+
+    # Initializes the object
+    # @param [Hash] attributes Model attributes in the form of hash
+    def initialize(attributes = {})
+      if (!attributes.is_a?(Hash))
+        fail ArgumentError, "The input argument (attributes) must be a hash in `XeroRuby::AppStore::UpdateUsageRecord` initialize method"
+      end
+
+      # check to see if the attribute exists and convert string to symbol for hash key
+      attributes = attributes.each_with_object({}) { |(k, v), h|
+        if (!self.class.attribute_map.key?(k.to_sym))
+          fail ArgumentError, "`#{k}` is not a valid attribute in `XeroRuby::AppStore::UpdateUsageRecord`. Please check the name to make sure it's valid. List of attributes: " + self.class.attribute_map.keys.inspect
+        end
+        h[k.to_sym] = v
+      }
+
+      if attributes.key?(:'quantity')
+        self.quantity = attributes[:'quantity']
+      end
+    end
+
+    # Show invalid properties with the reasons. Usually used together with valid?
+    # @return Array for valid properties with the reasons
+    def list_invalid_properties
+      invalid_properties = Array.new
+      if @quantity.nil?
+        invalid_properties.push('invalid value for "quantity", quantity cannot be nil.')
+      end
+
+      invalid_properties
+    end
+
+    # Check to see if the all the properties in the model are valid
+    # @return true if the model is valid
+    def valid?
+      return false if @quantity.nil?
+      true
+    end
+
+    # Checks equality by comparing each attribute.
+    # @param [Object] Object to be compared
+    def ==(o)
+      return true if self.equal?(o)
+      self.class == o.class &&
+          quantity == o.quantity
+    end
+
+    # @see the `==` method
+    # @param [Object] Object to be compared
+    def eql?(o)
+      self == o
+    end
+
+    # Calculates hash code according to all attributes.
+    # @return [Integer] Hash code
+    def hash
+      [quantity].hash
+    end
+
+    # Builds the object from hash
+    # @param [Hash] attributes Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    def self.build_from_hash(attributes)
+      new.build_from_hash(attributes)
+    end
+
+    # Builds the object from hash
+    # @param [Hash] attributes Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    def build_from_hash(attributes)
+      return nil unless attributes.is_a?(Hash)
+      self.class.openapi_types.each_pair do |key, type|
+        if type =~ /\AArray<(.*)>/i
+          # check to ensure the input is an array given that the attribute
+          # is documented as an array but the input is not
+          if attributes[self.class.attribute_map[key]].is_a?(Array)
+            self.send("#{key}=", attributes[self.class.attribute_map[key]].map { |v| _deserialize($1, v) })
+          end
+        elsif !attributes[self.class.attribute_map[key]].nil?
+          self.send("#{key}=", _deserialize(type, attributes[self.class.attribute_map[key]]))
+        end # or else data not found in attributes(hash), not an issue as the data can be optional
+      end
+
+      self
+    end
+
+    # Deserializes the data based on type
+    # @param string type Data type
+    # @param string value Value to be deserialized
+    # @return [Object] Deserialized data
+    def _deserialize(type, value)
+      case type.to_sym
+      when :DateTime
+        DateTime.parse(parse_date(value))
+      when :Date
+        Date.parse(parse_date(value))
+      when :String
+        value.to_s
+      when :Integer
+        value.to_i
+      when :Float
+        value.to_f
+      when :BigDecimal
+        BigDecimal(value.to_s)
+      when :Boolean
+        if value.to_s =~ /\A(true|t|yes|y|1)\z/i
+          true
+        else
+          false
+        end
+      when :Object
+        # generic object (usually a Hash), return directly
+        value
+      when /\AArray<(?<inner_type>.+)>\z/
+        inner_type = Regexp.last_match[:inner_type]
+        value.map { |v| _deserialize(inner_type, v) }
+      when /\AHash<(?<k_type>.+?), (?<v_type>.+)>\z/
+        k_type = Regexp.last_match[:k_type]
+        v_type = Regexp.last_match[:v_type]
+        {}.tap do |hash|
+          value.each do |k, v|
+            hash[_deserialize(k_type, k)] = _deserialize(v_type, v)
+          end
+        end
+      else # model
+        XeroRuby::AppStore.const_get(type).build_from_hash(value)
+      end
+    end
+
+    # Returns the string representation of the object
+    # @return [String] String presentation of the object
+    def to_s
+      to_hash.to_s
+    end
+
+    # to_body is an alias to to_hash (backward compatibility)
+    # @return [Hash] Returns the object in the form of hash
+    def to_body
+      to_hash
+    end
+
+    # Returns the object in the form of hash
+    # @return [Hash] Returns the object in the form of hash
+    def to_hash(downcase: false)
+      hash = {}
+      self.class.attribute_map.each_pair do |attr, param|
+        value = self.send(attr)
+        next if value.nil?
+        key = downcase ? attr : param
+        hash[key] = _to_hash(value, downcase: downcase)
+      end
+      hash
+    end
+
+    # Returns the object in the form of hash with snake_case
+    def to_attributes
+      to_hash(downcase: true)
+    end
+
+    # Outputs non-array value in the form of hash
+    # For object, use to_hash. Otherwise, just return the value
+    # @param [Object] value Any valid value
+    # @return [Hash] Returns the value in the form of hash
+    def _to_hash(value, downcase: false)
+      if value.is_a?(Array)
+        value.map do |v|
+          v.to_hash(downcase: downcase)
+        end
+      elsif value.is_a?(Hash)
+        {}.tap do |hash|
+          value.map { |k, v| hash[k] = _to_hash(v, downcase: downcase) }
+        end
+      elsif value.respond_to? :to_hash
+        value.to_hash(downcase: downcase)
+      else
+        value
+      end
+    end
+
+    def parse_date(datestring)
+      if datestring.include?('Date')
+        date_pattern = /\/Date\((-?\d+)(\+\d+)?\)\//
+        original, date, timezone = *date_pattern.match(datestring)
+        date = (date.to_i / 1000)
+        Time.at(date).utc.strftime('%Y-%m-%dT%H:%M:%S%z').to_s
+      elsif /(\d\d\d\d)-(\d\d)/.match(datestring) # handles dates w/out Days: YYYY-MM*-DD
+        Time.parse(datestring + '-01').strftime('%Y-%m-%dT%H:%M:%S').to_s
+      else # handle date 'types' for small subset of payroll API's
+        Time.parse(datestring).strftime('%Y-%m-%dT%H:%M:%S').to_s
+      end
+    end
+  end
+end
diff --git a/lib/xero-ruby/models/app_store/usage_record.rb b/lib/xero-ruby/models/app_store/usage_record.rb
new file mode 100644
index 00000000..8b5e1303
--- /dev/null
+++ b/lib/xero-ruby/models/app_store/usage_record.rb
@@ -0,0 +1,332 @@
+=begin
+#Xero AppStore API
+
+#These endpoints are for Xero Partners to interact with the App Store Billing platform
+
+Contact: api@xero.com
+Generated by: https://openapi-generator.tech
+OpenAPI Generator version: 4.3.1
+
+=end
+
+require 'time'
+require 'date'
+
+module XeroRuby::AppStore
+  require 'bigdecimal'
+
+  class UsageRecord
+    # The quantity recorded
+    attr_accessor :quantity
+    
+    # The unique identifier of the Subscription.
+    attr_accessor :subscription_id
+    
+    # The unique identifier of the SubscriptionItem.
+    attr_accessor :subscription_item_id
+    
+    # If the subscription is a test subscription
+    attr_accessor :test_mode
+    
+    # The time when this usage was recorded in UTC
+    attr_accessor :recorded_at
+    
+    # The unique identifier of the usageRecord.
+    attr_accessor :usage_record_id
+    
+    # The price per unit
+    attr_accessor :price_per_unit
+    
+    # The unique identifier of the linked Product
+    attr_accessor :product_id
+    
+    # Attribute mapping from ruby-style variable name to JSON key.
+    def self.attribute_map
+      {
+        :'quantity' => :'quantity',
+        :'subscription_id' => :'subscriptionId',
+        :'subscription_item_id' => :'subscriptionItemId',
+        :'test_mode' => :'testMode',
+        :'recorded_at' => :'recordedAt',
+        :'usage_record_id' => :'usageRecordId',
+        :'price_per_unit' => :'pricePerUnit',
+        :'product_id' => :'productId'
+      }
+    end
+
+    # Attribute type mapping.
+    def self.openapi_types
+      {
+        :'quantity' => :'Integer',
+        :'subscription_id' => :'String',
+        :'subscription_item_id' => :'String',
+        :'test_mode' => :'Boolean',
+        :'recorded_at' => :'DateTime',
+        :'usage_record_id' => :'String',
+        :'price_per_unit' => :'Float',
+        :'product_id' => :'String'
+      }
+    end
+
+    # Initializes the object
+    # @param [Hash] attributes Model attributes in the form of hash
+    def initialize(attributes = {})
+      if (!attributes.is_a?(Hash))
+        fail ArgumentError, "The input argument (attributes) must be a hash in `XeroRuby::AppStore::UsageRecord` initialize method"
+      end
+
+      # check to see if the attribute exists and convert string to symbol for hash key
+      attributes = attributes.each_with_object({}) { |(k, v), h|
+        if (!self.class.attribute_map.key?(k.to_sym))
+          fail ArgumentError, "`#{k}` is not a valid attribute in `XeroRuby::AppStore::UsageRecord`. Please check the name to make sure it's valid. List of attributes: " + self.class.attribute_map.keys.inspect
+        end
+        h[k.to_sym] = v
+      }
+
+      if attributes.key?(:'quantity')
+        self.quantity = attributes[:'quantity']
+      end
+
+      if attributes.key?(:'subscription_id')
+        self.subscription_id = attributes[:'subscription_id']
+      end
+
+      if attributes.key?(:'subscription_item_id')
+        self.subscription_item_id = attributes[:'subscription_item_id']
+      end
+
+      if attributes.key?(:'test_mode')
+        self.test_mode = attributes[:'test_mode']
+      end
+
+      if attributes.key?(:'recorded_at')
+        self.recorded_at = attributes[:'recorded_at']
+      end
+
+      if attributes.key?(:'usage_record_id')
+        self.usage_record_id = attributes[:'usage_record_id']
+      end
+
+      if attributes.key?(:'price_per_unit')
+        self.price_per_unit = attributes[:'price_per_unit']
+      end
+
+      if attributes.key?(:'product_id')
+        self.product_id = attributes[:'product_id']
+      end
+    end
+
+    # Show invalid properties with the reasons. Usually used together with valid?
+    # @return Array for valid properties with the reasons
+    def list_invalid_properties
+      invalid_properties = Array.new
+      if @quantity.nil?
+        invalid_properties.push('invalid value for "quantity", quantity cannot be nil.')
+      end
+
+      if @subscription_id.nil?
+        invalid_properties.push('invalid value for "subscription_id", subscription_id cannot be nil.')
+      end
+
+      if @subscription_item_id.nil?
+        invalid_properties.push('invalid value for "subscription_item_id", subscription_item_id cannot be nil.')
+      end
+
+      if @test_mode.nil?
+        invalid_properties.push('invalid value for "test_mode", test_mode cannot be nil.')
+      end
+
+      if @recorded_at.nil?
+        invalid_properties.push('invalid value for "recorded_at", recorded_at cannot be nil.')
+      end
+
+      if @usage_record_id.nil?
+        invalid_properties.push('invalid value for "usage_record_id", usage_record_id cannot be nil.')
+      end
+
+      if @price_per_unit.nil?
+        invalid_properties.push('invalid value for "price_per_unit", price_per_unit cannot be nil.')
+      end
+
+      if @product_id.nil?
+        invalid_properties.push('invalid value for "product_id", product_id cannot be nil.')
+      end
+
+      invalid_properties
+    end
+
+    # Check to see if the all the properties in the model are valid
+    # @return true if the model is valid
+    def valid?
+      return false if @quantity.nil?
+      return false if @subscription_id.nil?
+      return false if @subscription_item_id.nil?
+      return false if @test_mode.nil?
+      return false if @recorded_at.nil?
+      return false if @usage_record_id.nil?
+      return false if @price_per_unit.nil?
+      return false if @product_id.nil?
+      true
+    end
+
+    # Checks equality by comparing each attribute.
+    # @param [Object] Object to be compared
+    def ==(o)
+      return true if self.equal?(o)
+      self.class == o.class &&
+          quantity == o.quantity &&
+          subscription_id == o.subscription_id &&
+          subscription_item_id == o.subscription_item_id &&
+          test_mode == o.test_mode &&
+          recorded_at == o.recorded_at &&
+          usage_record_id == o.usage_record_id &&
+          price_per_unit == o.price_per_unit &&
+          product_id == o.product_id
+    end
+
+    # @see the `==` method
+    # @param [Object] Object to be compared
+    def eql?(o)
+      self == o
+    end
+
+    # Calculates hash code according to all attributes.
+    # @return [Integer] Hash code
+    def hash
+      [quantity, subscription_id, subscription_item_id, test_mode, recorded_at, usage_record_id, price_per_unit, product_id].hash
+    end
+
+    # Builds the object from hash
+    # @param [Hash] attributes Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    def self.build_from_hash(attributes)
+      new.build_from_hash(attributes)
+    end
+
+    # Builds the object from hash
+    # @param [Hash] attributes Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    def build_from_hash(attributes)
+      return nil unless attributes.is_a?(Hash)
+      self.class.openapi_types.each_pair do |key, type|
+        if type =~ /\AArray<(.*)>/i
+          # check to ensure the input is an array given that the attribute
+          # is documented as an array but the input is not
+          if attributes[self.class.attribute_map[key]].is_a?(Array)
+            self.send("#{key}=", attributes[self.class.attribute_map[key]].map { |v| _deserialize($1, v) })
+          end
+        elsif !attributes[self.class.attribute_map[key]].nil?
+          self.send("#{key}=", _deserialize(type, attributes[self.class.attribute_map[key]]))
+        end # or else data not found in attributes(hash), not an issue as the data can be optional
+      end
+
+      self
+    end
+
+    # Deserializes the data based on type
+    # @param string type Data type
+    # @param string value Value to be deserialized
+    # @return [Object] Deserialized data
+    def _deserialize(type, value)
+      case type.to_sym
+      when :DateTime
+        DateTime.parse(parse_date(value))
+      when :Date
+        Date.parse(parse_date(value))
+      when :String
+        value.to_s
+      when :Integer
+        value.to_i
+      when :Float
+        value.to_f
+      when :BigDecimal
+        BigDecimal(value.to_s)
+      when :Boolean
+        if value.to_s =~ /\A(true|t|yes|y|1)\z/i
+          true
+        else
+          false
+        end
+      when :Object
+        # generic object (usually a Hash), return directly
+        value
+      when /\AArray<(?<inner_type>.+)>\z/
+        inner_type = Regexp.last_match[:inner_type]
+        value.map { |v| _deserialize(inner_type, v) }
+      when /\AHash<(?<k_type>.+?), (?<v_type>.+)>\z/
+        k_type = Regexp.last_match[:k_type]
+        v_type = Regexp.last_match[:v_type]
+        {}.tap do |hash|
+          value.each do |k, v|
+            hash[_deserialize(k_type, k)] = _deserialize(v_type, v)
+          end
+        end
+      else # model
+        XeroRuby::AppStore.const_get(type).build_from_hash(value)
+      end
+    end
+
+    # Returns the string representation of the object
+    # @return [String] String presentation of the object
+    def to_s
+      to_hash.to_s
+    end
+
+    # to_body is an alias to to_hash (backward compatibility)
+    # @return [Hash] Returns the object in the form of hash
+    def to_body
+      to_hash
+    end
+
+    # Returns the object in the form of hash
+    # @return [Hash] Returns the object in the form of hash
+    def to_hash(downcase: false)
+      hash = {}
+      self.class.attribute_map.each_pair do |attr, param|
+        value = self.send(attr)
+        next if value.nil?
+        key = downcase ? attr : param
+        hash[key] = _to_hash(value, downcase: downcase)
+      end
+      hash
+    end
+
+    # Returns the object in the form of hash with snake_case
+    def to_attributes
+      to_hash(downcase: true)
+    end
+
+    # Outputs non-array value in the form of hash
+    # For object, use to_hash. Otherwise, just return the value
+    # @param [Object] value Any valid value
+    # @return [Hash] Returns the value in the form of hash
+    def _to_hash(value, downcase: false)
+      if value.is_a?(Array)
+        value.map do |v|
+          v.to_hash(downcase: downcase)
+        end
+      elsif value.is_a?(Hash)
+        {}.tap do |hash|
+          value.map { |k, v| hash[k] = _to_hash(v, downcase: downcase) }
+        end
+      elsif value.respond_to? :to_hash
+        value.to_hash(downcase: downcase)
+      else
+        value
+      end
+    end
+
+    def parse_date(datestring)
+      if datestring.include?('Date')
+        date_pattern = /\/Date\((-?\d+)(\+\d+)?\)\//
+        original, date, timezone = *date_pattern.match(datestring)
+        date = (date.to_i / 1000)
+        Time.at(date).utc.strftime('%Y-%m-%dT%H:%M:%S%z').to_s
+      elsif /(\d\d\d\d)-(\d\d)/.match(datestring) # handles dates w/out Days: YYYY-MM*-DD
+        Time.parse(datestring + '-01').strftime('%Y-%m-%dT%H:%M:%S').to_s
+      else # handle date 'types' for small subset of payroll API's
+        Time.parse(datestring).strftime('%Y-%m-%dT%H:%M:%S').to_s
+      end
+    end
+  end
+end
diff --git a/lib/xero-ruby/models/app_store/usage_records_list.rb b/lib/xero-ruby/models/app_store/usage_records_list.rb
new file mode 100644
index 00000000..fd07150b
--- /dev/null
+++ b/lib/xero-ruby/models/app_store/usage_records_list.rb
@@ -0,0 +1,230 @@
+=begin
+#Xero AppStore API
+
+#These endpoints are for Xero Partners to interact with the App Store Billing platform
+
+Contact: api@xero.com
+Generated by: https://openapi-generator.tech
+OpenAPI Generator version: 4.3.1
+
+=end
+
+require 'time'
+require 'date'
+
+module XeroRuby::AppStore
+  # Response to get usage record
+  require 'bigdecimal'
+
+  class UsageRecordsList
+    # A collection of usage records
+    attr_accessor :usage_records
+    
+    # Attribute mapping from ruby-style variable name to JSON key.
+    def self.attribute_map
+      {
+        :'usage_records' => :'usageRecords'
+      }
+    end
+
+    # Attribute type mapping.
+    def self.openapi_types
+      {
+        :'usage_records' => :'Array<UsageRecord>'
+      }
+    end
+
+    # Initializes the object
+    # @param [Hash] attributes Model attributes in the form of hash
+    def initialize(attributes = {})
+      if (!attributes.is_a?(Hash))
+        fail ArgumentError, "The input argument (attributes) must be a hash in `XeroRuby::AppStore::UsageRecordsList` initialize method"
+      end
+
+      # check to see if the attribute exists and convert string to symbol for hash key
+      attributes = attributes.each_with_object({}) { |(k, v), h|
+        if (!self.class.attribute_map.key?(k.to_sym))
+          fail ArgumentError, "`#{k}` is not a valid attribute in `XeroRuby::AppStore::UsageRecordsList`. Please check the name to make sure it's valid. List of attributes: " + self.class.attribute_map.keys.inspect
+        end
+        h[k.to_sym] = v
+      }
+
+      if attributes.key?(:'usage_records')
+        if (value = attributes[:'usage_records']).is_a?(Array)
+          self.usage_records = value
+        end
+      end
+    end
+
+    # Show invalid properties with the reasons. Usually used together with valid?
+    # @return Array for valid properties with the reasons
+    def list_invalid_properties
+      invalid_properties = Array.new
+      if @usage_records.nil?
+        invalid_properties.push('invalid value for "usage_records", usage_records cannot be nil.')
+      end
+
+      invalid_properties
+    end
+
+    # Check to see if the all the properties in the model are valid
+    # @return true if the model is valid
+    def valid?
+      return false if @usage_records.nil?
+      true
+    end
+
+    # Checks equality by comparing each attribute.
+    # @param [Object] Object to be compared
+    def ==(o)
+      return true if self.equal?(o)
+      self.class == o.class &&
+          usage_records == o.usage_records
+    end
+
+    # @see the `==` method
+    # @param [Object] Object to be compared
+    def eql?(o)
+      self == o
+    end
+
+    # Calculates hash code according to all attributes.
+    # @return [Integer] Hash code
+    def hash
+      [usage_records].hash
+    end
+
+    # Builds the object from hash
+    # @param [Hash] attributes Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    def self.build_from_hash(attributes)
+      new.build_from_hash(attributes)
+    end
+
+    # Builds the object from hash
+    # @param [Hash] attributes Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    def build_from_hash(attributes)
+      return nil unless attributes.is_a?(Hash)
+      self.class.openapi_types.each_pair do |key, type|
+        if type =~ /\AArray<(.*)>/i
+          # check to ensure the input is an array given that the attribute
+          # is documented as an array but the input is not
+          if attributes[self.class.attribute_map[key]].is_a?(Array)
+            self.send("#{key}=", attributes[self.class.attribute_map[key]].map { |v| _deserialize($1, v) })
+          end
+        elsif !attributes[self.class.attribute_map[key]].nil?
+          self.send("#{key}=", _deserialize(type, attributes[self.class.attribute_map[key]]))
+        end # or else data not found in attributes(hash), not an issue as the data can be optional
+      end
+
+      self
+    end
+
+    # Deserializes the data based on type
+    # @param string type Data type
+    # @param string value Value to be deserialized
+    # @return [Object] Deserialized data
+    def _deserialize(type, value)
+      case type.to_sym
+      when :DateTime
+        DateTime.parse(parse_date(value))
+      when :Date
+        Date.parse(parse_date(value))
+      when :String
+        value.to_s
+      when :Integer
+        value.to_i
+      when :Float
+        value.to_f
+      when :BigDecimal
+        BigDecimal(value.to_s)
+      when :Boolean
+        if value.to_s =~ /\A(true|t|yes|y|1)\z/i
+          true
+        else
+          false
+        end
+      when :Object
+        # generic object (usually a Hash), return directly
+        value
+      when /\AArray<(?<inner_type>.+)>\z/
+        inner_type = Regexp.last_match[:inner_type]
+        value.map { |v| _deserialize(inner_type, v) }
+      when /\AHash<(?<k_type>.+?), (?<v_type>.+)>\z/
+        k_type = Regexp.last_match[:k_type]
+        v_type = Regexp.last_match[:v_type]
+        {}.tap do |hash|
+          value.each do |k, v|
+            hash[_deserialize(k_type, k)] = _deserialize(v_type, v)
+          end
+        end
+      else # model
+        XeroRuby::AppStore.const_get(type).build_from_hash(value)
+      end
+    end
+
+    # Returns the string representation of the object
+    # @return [String] String presentation of the object
+    def to_s
+      to_hash.to_s
+    end
+
+    # to_body is an alias to to_hash (backward compatibility)
+    # @return [Hash] Returns the object in the form of hash
+    def to_body
+      to_hash
+    end
+
+    # Returns the object in the form of hash
+    # @return [Hash] Returns the object in the form of hash
+    def to_hash(downcase: false)
+      hash = {}
+      self.class.attribute_map.each_pair do |attr, param|
+        value = self.send(attr)
+        next if value.nil?
+        key = downcase ? attr : param
+        hash[key] = _to_hash(value, downcase: downcase)
+      end
+      hash
+    end
+
+    # Returns the object in the form of hash with snake_case
+    def to_attributes
+      to_hash(downcase: true)
+    end
+
+    # Outputs non-array value in the form of hash
+    # For object, use to_hash. Otherwise, just return the value
+    # @param [Object] value Any valid value
+    # @return [Hash] Returns the value in the form of hash
+    def _to_hash(value, downcase: false)
+      if value.is_a?(Array)
+        value.map do |v|
+          v.to_hash(downcase: downcase)
+        end
+      elsif value.is_a?(Hash)
+        {}.tap do |hash|
+          value.map { |k, v| hash[k] = _to_hash(v, downcase: downcase) }
+        end
+      elsif value.respond_to? :to_hash
+        value.to_hash(downcase: downcase)
+      else
+        value
+      end
+    end
+
+    def parse_date(datestring)
+      if datestring.include?('Date')
+        date_pattern = /\/Date\((-?\d+)(\+\d+)?\)\//
+        original, date, timezone = *date_pattern.match(datestring)
+        date = (date.to_i / 1000)
+        Time.at(date).utc.strftime('%Y-%m-%dT%H:%M:%S%z').to_s
+      elsif /(\d\d\d\d)-(\d\d)/.match(datestring) # handles dates w/out Days: YYYY-MM*-DD
+        Time.parse(datestring + '-01').strftime('%Y-%m-%dT%H:%M:%S').to_s
+      else # handle date 'types' for small subset of payroll API's
+        Time.parse(datestring).strftime('%Y-%m-%dT%H:%M:%S').to_s
+      end
+    end
+  end
+end
diff --git a/lib/xero-ruby/version.rb b/lib/xero-ruby/version.rb
index 61a2f8f1..068db37a 100644
--- a/lib/xero-ruby/version.rb
+++ b/lib/xero-ruby/version.rb
@@ -7,9 +7,9 @@
 Generated by: https://openapi-generator.tech
 OpenAPI Generator version: 4.3.1
 
-The version of the XeroOpenAPI document: 2.30.2
+The version of the XeroOpenAPI document: 2.31.0
 =end
 
 module XeroRuby
-  VERSION = '3.14.0'
+  VERSION = '3.15.0'
 end