use model class for request body with additionalProperties (#16613)

* try out simple fix * add test case * generate samples
2023-09-23 07:07:53 +02:00
parent f99002a974
commit 2ca99bdf8e
415 changed files with 20517 additions and 1 deletions
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -7234,7 +7234,7 @@ public class DefaultCodegen implements CodegenConfig {
    }

    protected void updateRequestBodyForMap(CodegenParameter codegenParameter, Schema schema, String name, Set<String> imports, String bodyParameterName) {
-        if (ModelUtils.isGenerateAliasAsModel(schema) && StringUtils.isNotBlank(name)) {
+        if (StringUtils.isNotBlank(name)) {
            this.addBodyModelSchema(codegenParameter, name, schema, imports, bodyParameterName, true);
        } else {
            Schema inner = ModelUtils.getAdditionalProperties(schema);
--- a/modules/openapi-generator/src/test/resources/3_0/csharp-netcore/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/csharp-netcore/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
@@ -980,6 +980,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/csharp/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/csharp/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
@@ -977,6 +977,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/go/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/go/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
@@ -965,6 +965,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/java/native/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/java/native/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
@@ -963,6 +963,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-okhttp-gson.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-okhttp-gson.yaml
@@ -939,6 +939,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
@@ -943,6 +943,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/javascript/petstore-with-fake-endpoints-models-for-testing.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/javascript/petstore-with-fake-endpoints-models-for-testing.yaml
@@ -978,6 +978,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
@@ -959,6 +959,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
@@ -1014,6 +1014,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/nullable:
    post:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/php-nextgen/petstore-with-fake-endpoints-models-for-testing.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/php-nextgen/petstore-with-fake-endpoints-models-for-testing.yaml
@@ -1014,6 +1014,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/nullable:
    post:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/php/petstore-with-fake-endpoints-models-for-testing.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/php/petstore-with-fake-endpoints-models-for-testing.yaml
@@ -1014,6 +1014,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/powershell/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/powershell/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
@@ -944,6 +944,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/python-prior/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/python-prior/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
@@ -1066,6 +1066,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/python/petstore-with-fake-endpoints-models-for-testing.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/python/petstore-with-fake-endpoints-models-for-testing.yaml
@@ -1002,6 +1002,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/date-time-query-params:
    put:
      tags:
--- a/modules/openapi-generator/src/test/resources/3_0/ruby/petstore-with-fake-endpoints-models-for-testing.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/ruby/petstore-with-fake-endpoints-models-for-testing.yaml
@@ -1050,6 +1050,27 @@ paths:
                type: string
        description: request body
        required: true
+  /fake/inline-freeform-additionalProperties:
+    post:
+      tags:
+        - fake
+      summary: test inline free-form additionalProperties
+      description: ''
+      operationId: testInlineFreeformAdditionalProperties
+      responses:
+        '200':
+          description: successful operation
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                someProperty:
+                  type: string
+              additionalProperties: true
+        description: request body
+        required: true
  /fake/body-with-query-params:
    put:
      tags:
--- a/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/.openapi-generator/FILES
@@ -90,6 +90,7 @@ docs/StoreApi.md
 docs/Tag.md
 docs/TestCollectionEndingWithWordList.md
 docs/TestCollectionEndingWithWordListObject.md
+docs/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/Triangle.md
 docs/TriangleInterface.md
 docs/User.md
@@ -209,6 +210,7 @@ src/Org.OpenAPITools/Model/SpecialModelName.cs
 src/Org.OpenAPITools/Model/Tag.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs
+src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/Org.OpenAPITools/Model/Triangle.cs
 src/Org.OpenAPITools/Model/TriangleInterface.cs
 src/Org.OpenAPITools/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/README.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/README.md
@@ -122,6 +122,7 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**TestEnumParameters**](docs/FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters
 *FakeApi* | [**TestGroupParameters**](docs/FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional)
 *FakeApi* | [**TestInlineAdditionalProperties**](docs/FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties
+*FakeApi* | [**TestInlineFreeformAdditionalProperties**](docs/FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties
 *FakeApi* | [**TestJsonFormData**](docs/FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data
 *FakeApi* | [**TestQueryParameterCollectionFormat**](docs/FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters | 
 *FakeClassnameTags123Api* | [**TestClassname**](docs/FakeClassnameTags123Api.md#testclassname) | **PATCH** /fake_classname_test | To test class name in snake case
@@ -232,6 +233,7 @@ Class | Method | HTTP request | Description
 - [Model.Tag](docs/Tag.md)
 - [Model.TestCollectionEndingWithWordList](docs/TestCollectionEndingWithWordList.md)
 - [Model.TestCollectionEndingWithWordListObject](docs/TestCollectionEndingWithWordListObject.md)
+ - [Model.TestInlineFreeformAdditionalPropertiesRequest](docs/TestInlineFreeformAdditionalPropertiesRequest.md)
 - [Model.Triangle](docs/Triangle.md)
 - [Model.TriangleInterface](docs/TriangleInterface.md)
 - [Model.User](docs/User.md)
--- a/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/docs/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/docs/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1205,6 +1206,91 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            var apiInstance = new FakeApi(config);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/docs/TestInlineFreeformAdditionalPropertiesRequest.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/docs/TestInlineFreeformAdditionalPropertiesRequest.md
@@ -0,0 +1,10 @@
+# Org.OpenAPITools.Model.TestInlineFreeformAdditionalPropertiesRequest
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**SomeProperty** | **string** |  | [optional] 
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
--- a/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
@@ -0,0 +1,66 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using Xunit;
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using Org.OpenAPITools.Model;
+using Org.OpenAPITools.Client;
+using System.Reflection;
+using Newtonsoft.Json;
+
+namespace Org.OpenAPITools.Test.Model
+{
+    /// <summary>
+    ///  Class for testing TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class TestInlineFreeformAdditionalPropertiesRequestTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for TestInlineFreeformAdditionalPropertiesRequest
+        //private TestInlineFreeformAdditionalPropertiesRequest instance;
+
+        public TestInlineFreeformAdditionalPropertiesRequestTests()
+        {
+            // TODO uncomment below to create an instance of TestInlineFreeformAdditionalPropertiesRequest
+            //instance = new TestInlineFreeformAdditionalPropertiesRequest();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of TestInlineFreeformAdditionalPropertiesRequest
+        /// </summary>
+        [Fact]
+        public void TestInlineFreeformAdditionalPropertiesRequestInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" TestInlineFreeformAdditionalPropertiesRequest
+            //Assert.IsType<TestInlineFreeformAdditionalPropertiesRequest>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'SomeProperty'
+        /// </summary>
+        [Fact]
+        public void SomePropertyTest()
+        {
+            // TODO unit test for the property 'SomeProperty'
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Api/FakeApi.cs
@@ -365,6 +365,26 @@ namespace Org.OpenAPITools.Api
        /// <returns>ApiResponse of Object(void)</returns>
        ApiResponse<Object> TestInlineAdditionalPropertiesWithHttpInfo(Dictionary<string, string> requestBody, int operationIndex = 0);
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns></returns>
+        void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0);
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0);
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
@@ -810,6 +830,31 @@ namespace Org.OpenAPITools.Api
        /// <returns>Task of ApiResponse</returns>
        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineAdditionalPropertiesWithHttpInfoAsync(Dictionary<string, string> requestBody, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <remarks>
@@ -3093,6 +3138,148 @@ namespace Org.OpenAPITools.Api
            return localVarResponse;
        }

+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns></returns>
+        public void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0)
+        {
+            TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        public Org.OpenAPITools.Client.ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0)
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+            {
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+            }
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+            }
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+            }
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+            localVarRequestOptions.Operation = "FakeApi.TestInlineFreeformAdditionalProperties";
+            localVarRequestOptions.OperationIndex = operationIndex;
+
+
+            // make the HTTP request
+            var localVarResponse = this.Client.Post<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration);
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null)
+                {
+                    throw _exception;
+                }
+            }
+
+            return localVarResponse;
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        public async System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            await TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(testInlineFreeformAdditionalPropertiesRequest, operationIndex, cancellationToken).ConfigureAwait(false);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        public async System.Threading.Tasks.Task<Org.OpenAPITools.Client.ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+            {
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+            }
+
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+            }
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+            }
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+            localVarRequestOptions.Operation = "FakeApi.TestInlineFreeformAdditionalProperties";
+            localVarRequestOptions.OperationIndex = operationIndex;
+
+
+            // make the HTTP request
+            var localVarResponse = await this.AsynchronousClient.PostAsync<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration, cancellationToken).ConfigureAwait(false);
+
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null)
+                {
+                    throw _exception;
+                }
+            }
+
+            return localVarResponse;
+        }
+
        /// <summary>
        /// test json serialization of form data 
        /// </summary>
--- a/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
@@ -0,0 +1,165 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Text.RegularExpressions;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+using Newtonsoft.Json.Linq;
+using System.ComponentModel.DataAnnotations;
+using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
+using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
+
+namespace Org.OpenAPITools.Model
+{
+    /// <summary>
+    /// TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    [DataContract(Name = "testInlineFreeformAdditionalProperties_request")]
+    public partial class TestInlineFreeformAdditionalPropertiesRequest : Dictionary<String, Object>, IEquatable<TestInlineFreeformAdditionalPropertiesRequest>, IValidatableObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestInlineFreeformAdditionalPropertiesRequest" /> class.
+        /// </summary>
+        /// <param name="someProperty">someProperty.</param>
+        public TestInlineFreeformAdditionalPropertiesRequest(string someProperty = default(string)) : base()
+        {
+            this._SomeProperty = someProperty;
+            if (this.SomeProperty != null)
+            {
+                this._flagSomeProperty = true;
+            }
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
+
+        /// <summary>
+        /// Gets or Sets SomeProperty
+        /// </summary>
+        [DataMember(Name = "someProperty", EmitDefaultValue = false)]
+        public string SomeProperty
+        {
+            get{ return _SomeProperty;}
+            set
+            {
+                _SomeProperty = value;
+                _flagSomeProperty = true;
+            }
+        }
+        private string _SomeProperty;
+        private bool _flagSomeProperty;
+
+        /// <summary>
+        /// Returns false as SomeProperty should not be serialized given that it's read-only.
+        /// </summary>
+        /// <returns>false (boolean)</returns>
+        public bool ShouldSerializeSomeProperty()
+        {
+            return _flagSomeProperty;
+        }
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class TestInlineFreeformAdditionalPropertiesRequest {\n");
+            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
+            sb.Append("  SomeProperty: ").Append(SomeProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return Newtonsoft.Json.JsonConvert.SerializeObject(this, Newtonsoft.Json.Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="input">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object input)
+        {
+            return OpenAPIClientUtils.compareLogic.Compare(this, input as TestInlineFreeformAdditionalPropertiesRequest).AreEqual;
+        }
+
+        /// <summary>
+        /// Returns true if TestInlineFreeformAdditionalPropertiesRequest instances are equal
+        /// </summary>
+        /// <param name="input">Instance of TestInlineFreeformAdditionalPropertiesRequest to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestInlineFreeformAdditionalPropertiesRequest input)
+        {
+            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                int hashCode = base.GetHashCode();
+                if (this.SomeProperty != null)
+                {
+                    hashCode = (hashCode * 59) + this.SomeProperty.GetHashCode();
+                }
+                if (this.AdditionalProperties != null)
+                {
+                    hashCode = (hashCode * 59) + this.AdditionalProperties.GetHashCode();
+                }
+                return hashCode;
+            }
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
+        {
+            return this.BaseValidate(validationContext);
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        protected IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> BaseValidate(ValidationContext validationContext)
+        {
+            yield break;
+        }
+    }
+
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/.openapi-generator/FILES
@@ -91,6 +91,7 @@ docs/models/SpecialModelName.md
 docs/models/Tag.md
 docs/models/TestCollectionEndingWithWordList.md
 docs/models/TestCollectionEndingWithWordListObject.md
+docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/models/Triangle.md
 docs/models/TriangleInterface.md
 docs/models/User.md
@@ -217,6 +218,7 @@ src/UseSourceGeneration/Model/SpecialModelName.cs
 src/UseSourceGeneration/Model/Tag.cs
 src/UseSourceGeneration/Model/TestCollectionEndingWithWordList.cs
 src/UseSourceGeneration/Model/TestCollectionEndingWithWordListObject.cs
+src/UseSourceGeneration/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/UseSourceGeneration/Model/Triangle.cs
 src/UseSourceGeneration/Model/TriangleInterface.cs
 src/UseSourceGeneration/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/docs/apis/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/docs/apis/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1205,6 +1206,91 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../../README.md#documentation-for-api-endpoints) [[Back to Model list]](../../README.md#documentation-for-models) [[Back to README]](../../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using UseSourceGeneration.Api;
+using UseSourceGeneration.Client;
+using UseSourceGeneration.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            var apiInstance = new FakeApi(config);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
@@ -0,0 +1,10 @@
+# UseSourceGeneration.Model.TestInlineFreeformAdditionalPropertiesRequest
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**SomeProperty** | **string** |  | [optional] 
+
+[[Back to Model list]](../../README.md#documentation-for-models) [[Back to API list]](../../README.md#documentation-for-api-endpoints) [[Back to README]](../../README.md)
+
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/src/UseSourceGeneration.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/src/UseSourceGeneration.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
@@ -0,0 +1,65 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using Xunit;
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using UseSourceGeneration.Model;
+using UseSourceGeneration.Client;
+using System.Reflection;
+
+namespace UseSourceGeneration.Test.Model
+{
+    /// <summary>
+    ///  Class for testing TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class TestInlineFreeformAdditionalPropertiesRequestTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for TestInlineFreeformAdditionalPropertiesRequest
+        //private TestInlineFreeformAdditionalPropertiesRequest instance;
+
+        public TestInlineFreeformAdditionalPropertiesRequestTests()
+        {
+            // TODO uncomment below to create an instance of TestInlineFreeformAdditionalPropertiesRequest
+            //instance = new TestInlineFreeformAdditionalPropertiesRequest();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of TestInlineFreeformAdditionalPropertiesRequest
+        /// </summary>
+        [Fact]
+        public void TestInlineFreeformAdditionalPropertiesRequestInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" TestInlineFreeformAdditionalPropertiesRequest
+            //Assert.IsType<TestInlineFreeformAdditionalPropertiesRequest>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'SomeProperty'
+        /// </summary>
+        [Fact]
+        public void SomePropertyTest()
+        {
+            // TODO unit test for the property 'SomeProperty'
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/src/UseSourceGeneration/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/src/UseSourceGeneration/Api/FakeApi.cs
@@ -384,6 +384,29 @@ namespace UseSourceGeneration.Api
        /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
        Task<ApiResponse<object>?> TestInlineAdditionalPropertiesOrDefaultAsync(Dictionary<string, string> requestBody, System.Threading.CancellationToken cancellationToken = default);

+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
+        Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default);
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
+        Task<ApiResponse<object>?> TestInlineFreeformAdditionalPropertiesOrDefaultAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default);
+
        /// <summary>
        /// test json serialization of form data
        /// </summary>
@@ -715,6 +738,26 @@ namespace UseSourceGeneration.Api
            OnErrorTestInlineAdditionalProperties?.Invoke(this, new ExceptionEventArgs(exception));
        }

+        /// <summary>
+        /// The event raised after the server response
+        /// </summary>
+        public event EventHandler<ApiResponseEventArgs<object>>? OnTestInlineFreeformAdditionalProperties;
+
+        /// <summary>
+        /// The event raised after an error querying the server
+        /// </summary>
+        public event EventHandler<ExceptionEventArgs>? OnErrorTestInlineFreeformAdditionalProperties;
+
+        internal void ExecuteOnTestInlineFreeformAdditionalProperties(ApiResponse<object> apiResponse)
+        {
+            OnTestInlineFreeformAdditionalProperties?.Invoke(this, new ApiResponseEventArgs<object>(apiResponse));
+        }
+
+        internal void ExecuteOnErrorTestInlineFreeformAdditionalProperties(Exception exception)
+        {
+            OnErrorTestInlineFreeformAdditionalProperties?.Invoke(this, new ExceptionEventArgs(exception));
+        }
+
        /// <summary>
        /// The event raised after the server response
        /// </summary>
@@ -2946,6 +2989,148 @@ namespace UseSourceGeneration.Api
            }
        }

+        partial void FormatTestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// Validates the request parameters
+        /// </summary>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <returns></returns>
+        private void ValidateTestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+                throw new ArgumentNullException(nameof(testInlineFreeformAdditionalPropertiesRequest));
+        }
+
+        /// <summary>
+        /// Processes the server response
+        /// </summary>
+        /// <param name="apiResponseLocalVar"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        private void AfterTestInlineFreeformAdditionalPropertiesDefaultImplementation(ApiResponse<object> apiResponseLocalVar, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            bool suppressDefaultLog = false;
+            AfterTestInlineFreeformAdditionalProperties(ref suppressDefaultLog, apiResponseLocalVar, testInlineFreeformAdditionalPropertiesRequest);
+            if (!suppressDefaultLog)
+                Logger.LogInformation("{0,-9} | {1} | {3}", (apiResponseLocalVar.DownloadedAt - apiResponseLocalVar.RequestedAt).TotalSeconds, apiResponseLocalVar.StatusCode, apiResponseLocalVar.Path);
+        }
+
+        /// <summary>
+        /// Processes the server response
+        /// </summary>
+        /// <param name="suppressDefaultLog"></param>
+        /// <param name="apiResponseLocalVar"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        partial void AfterTestInlineFreeformAdditionalProperties(ref bool suppressDefaultLog, ApiResponse<object> apiResponseLocalVar, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// Logs exceptions that occur while retrieving the server response
+        /// </summary>
+        /// <param name="exception"></param>
+        /// <param name="pathFormat"></param>
+        /// <param name="path"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        private void OnErrorTestInlineFreeformAdditionalPropertiesDefaultImplementation(Exception exception, string pathFormat, string path, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            bool suppressDefaultLog = false;
+            OnErrorTestInlineFreeformAdditionalProperties(ref suppressDefaultLog, exception, pathFormat, path, testInlineFreeformAdditionalPropertiesRequest);
+            if (!suppressDefaultLog)
+                Logger.LogError(exception, "An error occurred while sending the request to the server.");
+        }
+
+        /// <summary>
+        /// A partial method that gives developers a way to provide customized exception handling
+        /// </summary>
+        /// <param name="suppressDefaultLog"></param>
+        /// <param name="exception"></param>
+        /// <param name="pathFormat"></param>
+        /// <param name="path"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        partial void OnErrorTestInlineFreeformAdditionalProperties(ref bool suppressDefaultLog, Exception exception, string pathFormat, string path, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
+        public async Task<ApiResponse<object>?> TestInlineFreeformAdditionalPropertiesOrDefaultAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default)
+        {
+            try
+            {
+                return await TestInlineFreeformAdditionalPropertiesAsync(testInlineFreeformAdditionalPropertiesRequest, cancellationToken).ConfigureAwait(false);
+            }
+            catch (Exception)
+            {
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
+        public async Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default)
+        {
+            UriBuilder uriBuilderLocalVar = new UriBuilder();
+
+            try
+            {
+                ValidateTestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+
+                FormatTestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+
+                using (HttpRequestMessage httpRequestMessageLocalVar = new HttpRequestMessage())
+                {
+                    uriBuilderLocalVar.Host = HttpClient.BaseAddress!.Host;
+                    uriBuilderLocalVar.Port = HttpClient.BaseAddress.Port;
+                    uriBuilderLocalVar.Scheme = HttpClient.BaseAddress.Scheme;
+                    uriBuilderLocalVar.Path = ClientUtils.CONTEXT_PATH + "/fake/inline-freeform-additionalProperties";
+
+                    httpRequestMessageLocalVar.Content = (testInlineFreeformAdditionalPropertiesRequest as object) is System.IO.Stream stream
+                        ? httpRequestMessageLocalVar.Content = new StreamContent(stream)
+                        : httpRequestMessageLocalVar.Content = new StringContent(JsonSerializer.Serialize(testInlineFreeformAdditionalPropertiesRequest, _jsonSerializerOptions));
+
+                    httpRequestMessageLocalVar.RequestUri = uriBuilderLocalVar.Uri;
+
+                    string[] contentTypes = new string[] {
+                        "application/json"
+                    };
+
+                    string? contentTypeLocalVar = ClientUtils.SelectHeaderContentType(contentTypes);
+
+                    if (contentTypeLocalVar != null && httpRequestMessageLocalVar.Content != null)
+                        httpRequestMessageLocalVar.Content.Headers.ContentType = new MediaTypeHeaderValue(contentTypeLocalVar);
+
+                    httpRequestMessageLocalVar.Method = HttpMethod.Post;
+
+                    DateTime requestedAtLocalVar = DateTime.UtcNow;
+
+                    using (HttpResponseMessage httpResponseMessageLocalVar = await HttpClient.SendAsync(httpRequestMessageLocalVar, cancellationToken).ConfigureAwait(false))
+                    {
+                        string responseContentLocalVar = await httpResponseMessageLocalVar.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);
+
+                        ApiResponse<object> apiResponseLocalVar = new ApiResponse<object>(httpRequestMessageLocalVar, httpResponseMessageLocalVar, responseContentLocalVar, "/fake/inline-freeform-additionalProperties", requestedAtLocalVar, _jsonSerializerOptions);
+
+                        AfterTestInlineFreeformAdditionalPropertiesDefaultImplementation(apiResponseLocalVar, testInlineFreeformAdditionalPropertiesRequest);
+
+                        Events.ExecuteOnTestInlineFreeformAdditionalProperties(apiResponseLocalVar);
+
+                        return apiResponseLocalVar;
+                    }
+                }
+            }
+            catch(Exception e)
+            {
+                OnErrorTestInlineFreeformAdditionalPropertiesDefaultImplementation(e, "/fake/inline-freeform-additionalProperties", uriBuilderLocalVar.Path, testInlineFreeformAdditionalPropertiesRequest);
+                Events.ExecuteOnErrorTestInlineFreeformAdditionalProperties(e);
+                throw;
+            }
+        }
+
        partial void FormatTestJsonFormData(ref string param, ref string param2);

        /// <summary>
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/src/UseSourceGeneration/Client/HostConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/src/UseSourceGeneration/Client/HostConfiguration.cs
@@ -128,6 +128,7 @@ namespace UseSourceGeneration.Client
            _jsonOptions.Converters.Add(new TagJsonConverter());
            _jsonOptions.Converters.Add(new TestCollectionEndingWithWordListJsonConverter());
            _jsonOptions.Converters.Add(new TestCollectionEndingWithWordListObjectJsonConverter());
+            _jsonOptions.Converters.Add(new TestInlineFreeformAdditionalPropertiesRequestJsonConverter());
            _jsonOptions.Converters.Add(new TriangleJsonConverter());
            _jsonOptions.Converters.Add(new TriangleInterfaceJsonConverter());
            _jsonOptions.Converters.Add(new UserJsonConverter());
@@ -221,6 +222,7 @@ namespace UseSourceGeneration.Client
                new TagSerializationContext(),
                new TestCollectionEndingWithWordListSerializationContext(),
                new TestCollectionEndingWithWordListObjectSerializationContext(),
+                new TestInlineFreeformAdditionalPropertiesRequestSerializationContext(),
                new TriangleSerializationContext(),
                new TriangleInterfaceSerializationContext(),
                new UserSerializationContext(),
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/src/UseSourceGeneration/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt-useSourceGeneration/src/UseSourceGeneration/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
@@ -0,0 +1,184 @@
+// <auto-generated>
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+#nullable enable
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.ComponentModel.DataAnnotations;
+using OpenAPIClientUtils = UseSourceGeneration.Client.ClientUtils;
+using System.Text.Json.Serialization.Metadata;
+using UseSourceGeneration.Client;
+
+namespace UseSourceGeneration.Model
+{
+    /// <summary>
+    /// TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    public partial class TestInlineFreeformAdditionalPropertiesRequest : Dictionary<String, Object>, IValidatableObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestInlineFreeformAdditionalPropertiesRequest" /> class.
+        /// </summary>
+        /// <param name="someProperty">someProperty</param>
+        [JsonConstructor]
+        public TestInlineFreeformAdditionalPropertiesRequest(string someProperty) : base()
+        {
+            SomeProperty = someProperty;
+            OnCreated();
+        }
+
+        partial void OnCreated();
+
+        /// <summary>
+        /// Gets or Sets SomeProperty
+        /// </summary>
+        [JsonPropertyName("someProperty")]
+        public string SomeProperty { get; set; }
+
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public Dictionary<string, JsonElement> AdditionalProperties { get; } = new Dictionary<string, JsonElement>();
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class TestInlineFreeformAdditionalPropertiesRequest {\n");
+            sb.Append("  ").Append(base.ToString()?.Replace("\n", "\n  ")).Append("\n");
+            sb.Append("  SomeProperty: ").Append(SomeProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
+        {
+            return this.BaseValidate(validationContext);
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        protected IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> BaseValidate(ValidationContext validationContext)
+        {
+            yield break;
+        }
+    }
+
+    /// <summary>
+    /// A Json converter for type <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+    /// </summary>
+    public class TestInlineFreeformAdditionalPropertiesRequestJsonConverter : JsonConverter<TestInlineFreeformAdditionalPropertiesRequest>
+    {
+        /// <summary>
+        /// Deserializes json to <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="utf8JsonReader"></param>
+        /// <param name="typeToConvert"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <returns></returns>
+        /// <exception cref="JsonException"></exception>
+        public override TestInlineFreeformAdditionalPropertiesRequest Read(ref Utf8JsonReader utf8JsonReader, Type typeToConvert, JsonSerializerOptions jsonSerializerOptions)
+        {
+            int currentDepth = utf8JsonReader.CurrentDepth;
+
+            if (utf8JsonReader.TokenType != JsonTokenType.StartObject && utf8JsonReader.TokenType != JsonTokenType.StartArray)
+                throw new JsonException();
+
+            JsonTokenType startingTokenType = utf8JsonReader.TokenType;
+
+            string? someProperty = default;
+
+            while (utf8JsonReader.Read())
+            {
+                if (startingTokenType == JsonTokenType.StartObject && utf8JsonReader.TokenType == JsonTokenType.EndObject && currentDepth == utf8JsonReader.CurrentDepth)
+                    break;
+
+                if (startingTokenType == JsonTokenType.StartArray && utf8JsonReader.TokenType == JsonTokenType.EndArray && currentDepth == utf8JsonReader.CurrentDepth)
+                    break;
+
+                if (utf8JsonReader.TokenType == JsonTokenType.PropertyName && currentDepth == utf8JsonReader.CurrentDepth - 1)
+                {
+                    string? localVarJsonPropertyName = utf8JsonReader.GetString();
+                    utf8JsonReader.Read();
+
+                    switch (localVarJsonPropertyName)
+                    {
+                        case "someProperty":
+                            someProperty = utf8JsonReader.GetString();
+                            break;
+                        default:
+                            break;
+                    }
+                }
+            }
+
+            if (someProperty == null)
+                throw new ArgumentNullException(nameof(someProperty), "Property is required for class TestInlineFreeformAdditionalPropertiesRequest.");
+
+            return new TestInlineFreeformAdditionalPropertiesRequest(someProperty);
+        }
+
+        /// <summary>
+        /// Serializes a <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <exception cref="NotImplementedException"></exception>
+        public override void Write(Utf8JsonWriter writer, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, JsonSerializerOptions jsonSerializerOptions)
+        {
+            writer.WriteStartObject();
+
+            WriteProperties(ref writer, testInlineFreeformAdditionalPropertiesRequest, jsonSerializerOptions);
+            writer.WriteEndObject();
+        }
+
+        /// <summary>
+        /// Serializes the properties of <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <exception cref="NotImplementedException"></exception>
+        public void WriteProperties(ref Utf8JsonWriter writer, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, JsonSerializerOptions jsonSerializerOptions)
+        {
+            writer.WriteString("someProperty", testInlineFreeformAdditionalPropertiesRequest.SomeProperty);
+        }
+    }
+
+    /// <summary>
+    /// The TestInlineFreeformAdditionalPropertiesRequestSerializationContext
+    /// </summary>
+    [JsonSourceGenerationOptions(WriteIndented = true, GenerationMode = JsonSourceGenerationMode.Metadata | JsonSourceGenerationMode.Serialization)]
+    [JsonSerializable(typeof(TestInlineFreeformAdditionalPropertiesRequest))]
+    public partial class TestInlineFreeformAdditionalPropertiesRequestSerializationContext : JsonSerializerContext { }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/.openapi-generator/FILES
@@ -91,6 +91,7 @@ docs/models/SpecialModelName.md
 docs/models/Tag.md
 docs/models/TestCollectionEndingWithWordList.md
 docs/models/TestCollectionEndingWithWordListObject.md
+docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/models/Triangle.md
 docs/models/TriangleInterface.md
 docs/models/User.md
@@ -217,6 +218,7 @@ src/Org.OpenAPITools/Model/SpecialModelName.cs
 src/Org.OpenAPITools/Model/Tag.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs
+src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/Org.OpenAPITools/Model/Triangle.cs
 src/Org.OpenAPITools/Model/TriangleInterface.cs
 src/Org.OpenAPITools/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/docs/apis/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/docs/apis/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1205,6 +1206,91 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../../README.md#documentation-for-api-endpoints) [[Back to Model list]](../../README.md#documentation-for-models) [[Back to README]](../../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            var apiInstance = new FakeApi(config);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
@@ -0,0 +1,10 @@
+# Org.OpenAPITools.Model.TestInlineFreeformAdditionalPropertiesRequest
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**SomeProperty** | **string** |  | [optional] 
+
+[[Back to Model list]](../../README.md#documentation-for-models) [[Back to API list]](../../README.md#documentation-for-api-endpoints) [[Back to README]](../../README.md)
+
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
@@ -0,0 +1,65 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using Xunit;
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using Org.OpenAPITools.Model;
+using Org.OpenAPITools.Client;
+using System.Reflection;
+
+namespace Org.OpenAPITools.Test.Model
+{
+    /// <summary>
+    ///  Class for testing TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class TestInlineFreeformAdditionalPropertiesRequestTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for TestInlineFreeformAdditionalPropertiesRequest
+        //private TestInlineFreeformAdditionalPropertiesRequest instance;
+
+        public TestInlineFreeformAdditionalPropertiesRequestTests()
+        {
+            // TODO uncomment below to create an instance of TestInlineFreeformAdditionalPropertiesRequest
+            //instance = new TestInlineFreeformAdditionalPropertiesRequest();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of TestInlineFreeformAdditionalPropertiesRequest
+        /// </summary>
+        [Fact]
+        public void TestInlineFreeformAdditionalPropertiesRequestInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" TestInlineFreeformAdditionalPropertiesRequest
+            //Assert.IsType<TestInlineFreeformAdditionalPropertiesRequest>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'SomeProperty'
+        /// </summary>
+        [Fact]
+        public void SomePropertyTest()
+        {
+            // TODO unit test for the property 'SomeProperty'
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Api/FakeApi.cs
@@ -384,6 +384,29 @@ namespace Org.OpenAPITools.Api
        /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
        Task<ApiResponse<object>?> TestInlineAdditionalPropertiesOrDefaultAsync(Dictionary<string, string> requestBody, System.Threading.CancellationToken cancellationToken = default);

+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
+        Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default);
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
+        Task<ApiResponse<object>?> TestInlineFreeformAdditionalPropertiesOrDefaultAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default);
+
        /// <summary>
        /// test json serialization of form data
        /// </summary>
@@ -715,6 +738,26 @@ namespace Org.OpenAPITools.Api
            OnErrorTestInlineAdditionalProperties?.Invoke(this, new ExceptionEventArgs(exception));
        }

+        /// <summary>
+        /// The event raised after the server response
+        /// </summary>
+        public event EventHandler<ApiResponseEventArgs<object>>? OnTestInlineFreeformAdditionalProperties;
+
+        /// <summary>
+        /// The event raised after an error querying the server
+        /// </summary>
+        public event EventHandler<ExceptionEventArgs>? OnErrorTestInlineFreeformAdditionalProperties;
+
+        internal void ExecuteOnTestInlineFreeformAdditionalProperties(ApiResponse<object> apiResponse)
+        {
+            OnTestInlineFreeformAdditionalProperties?.Invoke(this, new ApiResponseEventArgs<object>(apiResponse));
+        }
+
+        internal void ExecuteOnErrorTestInlineFreeformAdditionalProperties(Exception exception)
+        {
+            OnErrorTestInlineFreeformAdditionalProperties?.Invoke(this, new ExceptionEventArgs(exception));
+        }
+
        /// <summary>
        /// The event raised after the server response
        /// </summary>
@@ -2946,6 +2989,148 @@ namespace Org.OpenAPITools.Api
            }
        }

+        partial void FormatTestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// Validates the request parameters
+        /// </summary>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <returns></returns>
+        private void ValidateTestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+                throw new ArgumentNullException(nameof(testInlineFreeformAdditionalPropertiesRequest));
+        }
+
+        /// <summary>
+        /// Processes the server response
+        /// </summary>
+        /// <param name="apiResponseLocalVar"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        private void AfterTestInlineFreeformAdditionalPropertiesDefaultImplementation(ApiResponse<object> apiResponseLocalVar, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            bool suppressDefaultLog = false;
+            AfterTestInlineFreeformAdditionalProperties(ref suppressDefaultLog, apiResponseLocalVar, testInlineFreeformAdditionalPropertiesRequest);
+            if (!suppressDefaultLog)
+                Logger.LogInformation("{0,-9} | {1} | {3}", (apiResponseLocalVar.DownloadedAt - apiResponseLocalVar.RequestedAt).TotalSeconds, apiResponseLocalVar.StatusCode, apiResponseLocalVar.Path);
+        }
+
+        /// <summary>
+        /// Processes the server response
+        /// </summary>
+        /// <param name="suppressDefaultLog"></param>
+        /// <param name="apiResponseLocalVar"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        partial void AfterTestInlineFreeformAdditionalProperties(ref bool suppressDefaultLog, ApiResponse<object> apiResponseLocalVar, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// Logs exceptions that occur while retrieving the server response
+        /// </summary>
+        /// <param name="exception"></param>
+        /// <param name="pathFormat"></param>
+        /// <param name="path"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        private void OnErrorTestInlineFreeformAdditionalPropertiesDefaultImplementation(Exception exception, string pathFormat, string path, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            bool suppressDefaultLog = false;
+            OnErrorTestInlineFreeformAdditionalProperties(ref suppressDefaultLog, exception, pathFormat, path, testInlineFreeformAdditionalPropertiesRequest);
+            if (!suppressDefaultLog)
+                Logger.LogError(exception, "An error occurred while sending the request to the server.");
+        }
+
+        /// <summary>
+        /// A partial method that gives developers a way to provide customized exception handling
+        /// </summary>
+        /// <param name="suppressDefaultLog"></param>
+        /// <param name="exception"></param>
+        /// <param name="pathFormat"></param>
+        /// <param name="path"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        partial void OnErrorTestInlineFreeformAdditionalProperties(ref bool suppressDefaultLog, Exception exception, string pathFormat, string path, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
+        public async Task<ApiResponse<object>?> TestInlineFreeformAdditionalPropertiesOrDefaultAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default)
+        {
+            try
+            {
+                return await TestInlineFreeformAdditionalPropertiesAsync(testInlineFreeformAdditionalPropertiesRequest, cancellationToken).ConfigureAwait(false);
+            }
+            catch (Exception)
+            {
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
+        public async Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default)
+        {
+            UriBuilder uriBuilderLocalVar = new UriBuilder();
+
+            try
+            {
+                ValidateTestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+
+                FormatTestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+
+                using (HttpRequestMessage httpRequestMessageLocalVar = new HttpRequestMessage())
+                {
+                    uriBuilderLocalVar.Host = HttpClient.BaseAddress!.Host;
+                    uriBuilderLocalVar.Port = HttpClient.BaseAddress.Port;
+                    uriBuilderLocalVar.Scheme = HttpClient.BaseAddress.Scheme;
+                    uriBuilderLocalVar.Path = ClientUtils.CONTEXT_PATH + "/fake/inline-freeform-additionalProperties";
+
+                    httpRequestMessageLocalVar.Content = (testInlineFreeformAdditionalPropertiesRequest as object) is System.IO.Stream stream
+                        ? httpRequestMessageLocalVar.Content = new StreamContent(stream)
+                        : httpRequestMessageLocalVar.Content = new StringContent(JsonSerializer.Serialize(testInlineFreeformAdditionalPropertiesRequest, _jsonSerializerOptions));
+
+                    httpRequestMessageLocalVar.RequestUri = uriBuilderLocalVar.Uri;
+
+                    string[] contentTypes = new string[] {
+                        "application/json"
+                    };
+
+                    string? contentTypeLocalVar = ClientUtils.SelectHeaderContentType(contentTypes);
+
+                    if (contentTypeLocalVar != null && httpRequestMessageLocalVar.Content != null)
+                        httpRequestMessageLocalVar.Content.Headers.ContentType = new MediaTypeHeaderValue(contentTypeLocalVar);
+
+                    httpRequestMessageLocalVar.Method = HttpMethod.Post;
+
+                    DateTime requestedAtLocalVar = DateTime.UtcNow;
+
+                    using (HttpResponseMessage httpResponseMessageLocalVar = await HttpClient.SendAsync(httpRequestMessageLocalVar, cancellationToken).ConfigureAwait(false))
+                    {
+                        string responseContentLocalVar = await httpResponseMessageLocalVar.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);
+
+                        ApiResponse<object> apiResponseLocalVar = new ApiResponse<object>(httpRequestMessageLocalVar, httpResponseMessageLocalVar, responseContentLocalVar, "/fake/inline-freeform-additionalProperties", requestedAtLocalVar, _jsonSerializerOptions);
+
+                        AfterTestInlineFreeformAdditionalPropertiesDefaultImplementation(apiResponseLocalVar, testInlineFreeformAdditionalPropertiesRequest);
+
+                        Events.ExecuteOnTestInlineFreeformAdditionalProperties(apiResponseLocalVar);
+
+                        return apiResponseLocalVar;
+                    }
+                }
+            }
+            catch(Exception e)
+            {
+                OnErrorTestInlineFreeformAdditionalPropertiesDefaultImplementation(e, "/fake/inline-freeform-additionalProperties", uriBuilderLocalVar.Path, testInlineFreeformAdditionalPropertiesRequest);
+                Events.ExecuteOnErrorTestInlineFreeformAdditionalProperties(e);
+                throw;
+            }
+        }
+
        partial void FormatTestJsonFormData(ref string param, ref string param2);

        /// <summary>
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Client/HostConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Client/HostConfiguration.cs
@@ -128,6 +128,7 @@ namespace Org.OpenAPITools.Client
            _jsonOptions.Converters.Add(new TagJsonConverter());
            _jsonOptions.Converters.Add(new TestCollectionEndingWithWordListJsonConverter());
            _jsonOptions.Converters.Add(new TestCollectionEndingWithWordListObjectJsonConverter());
+            _jsonOptions.Converters.Add(new TestInlineFreeformAdditionalPropertiesRequestJsonConverter());
            _jsonOptions.Converters.Add(new TriangleJsonConverter());
            _jsonOptions.Converters.Add(new TriangleInterfaceJsonConverter());
            _jsonOptions.Converters.Add(new UserJsonConverter());
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
@@ -0,0 +1,175 @@
+// <auto-generated>
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+#nullable enable
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.ComponentModel.DataAnnotations;
+using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
+
+namespace Org.OpenAPITools.Model
+{
+    /// <summary>
+    /// TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    public partial class TestInlineFreeformAdditionalPropertiesRequest : Dictionary<String, Object>, IValidatableObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestInlineFreeformAdditionalPropertiesRequest" /> class.
+        /// </summary>
+        /// <param name="someProperty">someProperty</param>
+        [JsonConstructor]
+        public TestInlineFreeformAdditionalPropertiesRequest(string someProperty) : base()
+        {
+            SomeProperty = someProperty;
+            OnCreated();
+        }
+
+        partial void OnCreated();
+
+        /// <summary>
+        /// Gets or Sets SomeProperty
+        /// </summary>
+        [JsonPropertyName("someProperty")]
+        public string SomeProperty { get; set; }
+
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public Dictionary<string, JsonElement> AdditionalProperties { get; } = new Dictionary<string, JsonElement>();
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class TestInlineFreeformAdditionalPropertiesRequest {\n");
+            sb.Append("  ").Append(base.ToString()?.Replace("\n", "\n  ")).Append("\n");
+            sb.Append("  SomeProperty: ").Append(SomeProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
+        {
+            return this.BaseValidate(validationContext);
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        protected IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> BaseValidate(ValidationContext validationContext)
+        {
+            yield break;
+        }
+    }
+
+    /// <summary>
+    /// A Json converter for type <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+    /// </summary>
+    public class TestInlineFreeformAdditionalPropertiesRequestJsonConverter : JsonConverter<TestInlineFreeformAdditionalPropertiesRequest>
+    {
+        /// <summary>
+        /// Deserializes json to <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="utf8JsonReader"></param>
+        /// <param name="typeToConvert"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <returns></returns>
+        /// <exception cref="JsonException"></exception>
+        public override TestInlineFreeformAdditionalPropertiesRequest Read(ref Utf8JsonReader utf8JsonReader, Type typeToConvert, JsonSerializerOptions jsonSerializerOptions)
+        {
+            int currentDepth = utf8JsonReader.CurrentDepth;
+
+            if (utf8JsonReader.TokenType != JsonTokenType.StartObject && utf8JsonReader.TokenType != JsonTokenType.StartArray)
+                throw new JsonException();
+
+            JsonTokenType startingTokenType = utf8JsonReader.TokenType;
+
+            string? someProperty = default;
+
+            while (utf8JsonReader.Read())
+            {
+                if (startingTokenType == JsonTokenType.StartObject && utf8JsonReader.TokenType == JsonTokenType.EndObject && currentDepth == utf8JsonReader.CurrentDepth)
+                    break;
+
+                if (startingTokenType == JsonTokenType.StartArray && utf8JsonReader.TokenType == JsonTokenType.EndArray && currentDepth == utf8JsonReader.CurrentDepth)
+                    break;
+
+                if (utf8JsonReader.TokenType == JsonTokenType.PropertyName && currentDepth == utf8JsonReader.CurrentDepth - 1)
+                {
+                    string? localVarJsonPropertyName = utf8JsonReader.GetString();
+                    utf8JsonReader.Read();
+
+                    switch (localVarJsonPropertyName)
+                    {
+                        case "someProperty":
+                            someProperty = utf8JsonReader.GetString();
+                            break;
+                        default:
+                            break;
+                    }
+                }
+            }
+
+            if (someProperty == null)
+                throw new ArgumentNullException(nameof(someProperty), "Property is required for class TestInlineFreeformAdditionalPropertiesRequest.");
+
+            return new TestInlineFreeformAdditionalPropertiesRequest(someProperty);
+        }
+
+        /// <summary>
+        /// Serializes a <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <exception cref="NotImplementedException"></exception>
+        public override void Write(Utf8JsonWriter writer, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, JsonSerializerOptions jsonSerializerOptions)
+        {
+            writer.WriteStartObject();
+
+            WriteProperties(ref writer, testInlineFreeformAdditionalPropertiesRequest, jsonSerializerOptions);
+            writer.WriteEndObject();
+        }
+
+        /// <summary>
+        /// Serializes the properties of <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <exception cref="NotImplementedException"></exception>
+        public void WriteProperties(ref Utf8JsonWriter writer, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, JsonSerializerOptions jsonSerializerOptions)
+        {
+            writer.WriteString("someProperty", testInlineFreeformAdditionalPropertiesRequest.SomeProperty);
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/.openapi-generator/FILES
@@ -91,6 +91,7 @@ docs/models/SpecialModelName.md
 docs/models/Tag.md
 docs/models/TestCollectionEndingWithWordList.md
 docs/models/TestCollectionEndingWithWordListObject.md
+docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/models/Triangle.md
 docs/models/TriangleInterface.md
 docs/models/User.md
@@ -217,6 +218,7 @@ src/Org.OpenAPITools/Model/SpecialModelName.cs
 src/Org.OpenAPITools/Model/Tag.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs
+src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/Org.OpenAPITools/Model/Triangle.cs
 src/Org.OpenAPITools/Model/TriangleInterface.cs
 src/Org.OpenAPITools/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/docs/apis/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/docs/apis/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1205,6 +1206,91 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../../README.md#documentation-for-api-endpoints) [[Back to Model list]](../../README.md#documentation-for-models) [[Back to README]](../../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            var apiInstance = new FakeApi(config);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
@@ -0,0 +1,10 @@
+# Org.OpenAPITools.Model.TestInlineFreeformAdditionalPropertiesRequest
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**SomeProperty** | **string** |  | [optional] 
+
+[[Back to Model list]](../../README.md#documentation-for-models) [[Back to API list]](../../README.md#documentation-for-api-endpoints) [[Back to README]](../../README.md)
+
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
@@ -0,0 +1,65 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using Xunit;
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using Org.OpenAPITools.Model;
+using Org.OpenAPITools.Client;
+using System.Reflection;
+
+namespace Org.OpenAPITools.Test.Model
+{
+    /// <summary>
+    ///  Class for testing TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class TestInlineFreeformAdditionalPropertiesRequestTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for TestInlineFreeformAdditionalPropertiesRequest
+        //private TestInlineFreeformAdditionalPropertiesRequest instance;
+
+        public TestInlineFreeformAdditionalPropertiesRequestTests()
+        {
+            // TODO uncomment below to create an instance of TestInlineFreeformAdditionalPropertiesRequest
+            //instance = new TestInlineFreeformAdditionalPropertiesRequest();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of TestInlineFreeformAdditionalPropertiesRequest
+        /// </summary>
+        [Fact]
+        public void TestInlineFreeformAdditionalPropertiesRequestInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" TestInlineFreeformAdditionalPropertiesRequest
+            //Assert.IsType<TestInlineFreeformAdditionalPropertiesRequest>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'SomeProperty'
+        /// </summary>
+        [Fact]
+        public void SomePropertyTest()
+        {
+            // TODO unit test for the property 'SomeProperty'
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/src/Org.OpenAPITools/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/src/Org.OpenAPITools/Api/FakeApi.cs
@@ -382,6 +382,29 @@ namespace Org.OpenAPITools.Api
        /// <returns>Task&lt;ApiResponse&gt;object&gt;&gt;</returns>
        Task<ApiResponse<object>> TestInlineAdditionalPropertiesOrDefaultAsync(Dictionary<string, string> requestBody, System.Threading.CancellationToken cancellationToken = default);

+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
+        Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default);
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task&lt;ApiResponse&gt;object&gt;&gt;</returns>
+        Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesOrDefaultAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default);
+
        /// <summary>
        /// test json serialization of form data
        /// </summary>
@@ -713,6 +736,26 @@ namespace Org.OpenAPITools.Api
            OnErrorTestInlineAdditionalProperties?.Invoke(this, new ExceptionEventArgs(exception));
        }

+        /// <summary>
+        /// The event raised after the server response
+        /// </summary>
+        public event EventHandler<ApiResponseEventArgs<object>> OnTestInlineFreeformAdditionalProperties;
+
+        /// <summary>
+        /// The event raised after an error querying the server
+        /// </summary>
+        public event EventHandler<ExceptionEventArgs> OnErrorTestInlineFreeformAdditionalProperties;
+
+        internal void ExecuteOnTestInlineFreeformAdditionalProperties(ApiResponse<object> apiResponse)
+        {
+            OnTestInlineFreeformAdditionalProperties?.Invoke(this, new ApiResponseEventArgs<object>(apiResponse));
+        }
+
+        internal void ExecuteOnErrorTestInlineFreeformAdditionalProperties(Exception exception)
+        {
+            OnErrorTestInlineFreeformAdditionalProperties?.Invoke(this, new ExceptionEventArgs(exception));
+        }
+
        /// <summary>
        /// The event raised after the server response
        /// </summary>
@@ -2944,6 +2987,148 @@ namespace Org.OpenAPITools.Api
            }
        }

+        partial void FormatTestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// Validates the request parameters
+        /// </summary>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <returns></returns>
+        private void ValidateTestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+                throw new ArgumentNullException(nameof(testInlineFreeformAdditionalPropertiesRequest));
+        }
+
+        /// <summary>
+        /// Processes the server response
+        /// </summary>
+        /// <param name="apiResponseLocalVar"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        private void AfterTestInlineFreeformAdditionalPropertiesDefaultImplementation(ApiResponse<object> apiResponseLocalVar, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            bool suppressDefaultLog = false;
+            AfterTestInlineFreeformAdditionalProperties(ref suppressDefaultLog, apiResponseLocalVar, testInlineFreeformAdditionalPropertiesRequest);
+            if (!suppressDefaultLog)
+                Logger.LogInformation("{0,-9} | {1} | {3}", (apiResponseLocalVar.DownloadedAt - apiResponseLocalVar.RequestedAt).TotalSeconds, apiResponseLocalVar.StatusCode, apiResponseLocalVar.Path);
+        }
+
+        /// <summary>
+        /// Processes the server response
+        /// </summary>
+        /// <param name="suppressDefaultLog"></param>
+        /// <param name="apiResponseLocalVar"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        partial void AfterTestInlineFreeformAdditionalProperties(ref bool suppressDefaultLog, ApiResponse<object> apiResponseLocalVar, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// Logs exceptions that occur while retrieving the server response
+        /// </summary>
+        /// <param name="exception"></param>
+        /// <param name="pathFormat"></param>
+        /// <param name="path"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        private void OnErrorTestInlineFreeformAdditionalPropertiesDefaultImplementation(Exception exception, string pathFormat, string path, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            bool suppressDefaultLog = false;
+            OnErrorTestInlineFreeformAdditionalProperties(ref suppressDefaultLog, exception, pathFormat, path, testInlineFreeformAdditionalPropertiesRequest);
+            if (!suppressDefaultLog)
+                Logger.LogError(exception, "An error occurred while sending the request to the server.");
+        }
+
+        /// <summary>
+        /// A partial method that gives developers a way to provide customized exception handling
+        /// </summary>
+        /// <param name="suppressDefaultLog"></param>
+        /// <param name="exception"></param>
+        /// <param name="pathFormat"></param>
+        /// <param name="path"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        partial void OnErrorTestInlineFreeformAdditionalProperties(ref bool suppressDefaultLog, Exception exception, string pathFormat, string path, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
+        public async Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesOrDefaultAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default)
+        {
+            try
+            {
+                return await TestInlineFreeformAdditionalPropertiesAsync(testInlineFreeformAdditionalPropertiesRequest, cancellationToken).ConfigureAwait(false);
+            }
+            catch (Exception)
+            {
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
+        public async Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default)
+        {
+            UriBuilder uriBuilderLocalVar = new UriBuilder();
+
+            try
+            {
+                ValidateTestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+
+                FormatTestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+
+                using (HttpRequestMessage httpRequestMessageLocalVar = new HttpRequestMessage())
+                {
+                    uriBuilderLocalVar.Host = HttpClient.BaseAddress.Host;
+                    uriBuilderLocalVar.Port = HttpClient.BaseAddress.Port;
+                    uriBuilderLocalVar.Scheme = HttpClient.BaseAddress.Scheme;
+                    uriBuilderLocalVar.Path = ClientUtils.CONTEXT_PATH + "/fake/inline-freeform-additionalProperties";
+
+                    httpRequestMessageLocalVar.Content = (testInlineFreeformAdditionalPropertiesRequest as object) is System.IO.Stream stream
+                        ? httpRequestMessageLocalVar.Content = new StreamContent(stream)
+                        : httpRequestMessageLocalVar.Content = new StringContent(JsonSerializer.Serialize(testInlineFreeformAdditionalPropertiesRequest, _jsonSerializerOptions));
+
+                    httpRequestMessageLocalVar.RequestUri = uriBuilderLocalVar.Uri;
+
+                    string[] contentTypes = new string[] {
+                        "application/json"
+                    };
+
+                    string contentTypeLocalVar = ClientUtils.SelectHeaderContentType(contentTypes);
+
+                    if (contentTypeLocalVar != null && httpRequestMessageLocalVar.Content != null)
+                        httpRequestMessageLocalVar.Content.Headers.ContentType = new MediaTypeHeaderValue(contentTypeLocalVar);
+
+                    httpRequestMessageLocalVar.Method = HttpMethod.Post;
+
+                    DateTime requestedAtLocalVar = DateTime.UtcNow;
+
+                    using (HttpResponseMessage httpResponseMessageLocalVar = await HttpClient.SendAsync(httpRequestMessageLocalVar, cancellationToken).ConfigureAwait(false))
+                    {
+                        string responseContentLocalVar = await httpResponseMessageLocalVar.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);
+
+                        ApiResponse<object> apiResponseLocalVar = new ApiResponse<object>(httpRequestMessageLocalVar, httpResponseMessageLocalVar, responseContentLocalVar, "/fake/inline-freeform-additionalProperties", requestedAtLocalVar, _jsonSerializerOptions);
+
+                        AfterTestInlineFreeformAdditionalPropertiesDefaultImplementation(apiResponseLocalVar, testInlineFreeformAdditionalPropertiesRequest);
+
+                        Events.ExecuteOnTestInlineFreeformAdditionalProperties(apiResponseLocalVar);
+
+                        return apiResponseLocalVar;
+                    }
+                }
+            }
+            catch(Exception e)
+            {
+                OnErrorTestInlineFreeformAdditionalPropertiesDefaultImplementation(e, "/fake/inline-freeform-additionalProperties", uriBuilderLocalVar.Path, testInlineFreeformAdditionalPropertiesRequest);
+                Events.ExecuteOnErrorTestInlineFreeformAdditionalProperties(e);
+                throw;
+            }
+        }
+
        partial void FormatTestJsonFormData(ref string param, ref string param2);

        /// <summary>
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/src/Org.OpenAPITools/Client/HostConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/src/Org.OpenAPITools/Client/HostConfiguration.cs
@@ -126,6 +126,7 @@ namespace Org.OpenAPITools.Client
            _jsonOptions.Converters.Add(new TagJsonConverter());
            _jsonOptions.Converters.Add(new TestCollectionEndingWithWordListJsonConverter());
            _jsonOptions.Converters.Add(new TestCollectionEndingWithWordListObjectJsonConverter());
+            _jsonOptions.Converters.Add(new TestInlineFreeformAdditionalPropertiesRequestJsonConverter());
            _jsonOptions.Converters.Add(new TriangleJsonConverter());
            _jsonOptions.Converters.Add(new TriangleInterfaceJsonConverter());
            _jsonOptions.Converters.Add(new UserJsonConverter());
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-net6.0/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
@@ -0,0 +1,173 @@
+// <auto-generated>
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.ComponentModel.DataAnnotations;
+using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
+
+namespace Org.OpenAPITools.Model
+{
+    /// <summary>
+    /// TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    public partial class TestInlineFreeformAdditionalPropertiesRequest : Dictionary<String, Object>, IValidatableObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestInlineFreeformAdditionalPropertiesRequest" /> class.
+        /// </summary>
+        /// <param name="someProperty">someProperty</param>
+        [JsonConstructor]
+        public TestInlineFreeformAdditionalPropertiesRequest(string someProperty) : base()
+        {
+            SomeProperty = someProperty;
+            OnCreated();
+        }
+
+        partial void OnCreated();
+
+        /// <summary>
+        /// Gets or Sets SomeProperty
+        /// </summary>
+        [JsonPropertyName("someProperty")]
+        public string SomeProperty { get; set; }
+
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public Dictionary<string, JsonElement> AdditionalProperties { get; } = new Dictionary<string, JsonElement>();
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class TestInlineFreeformAdditionalPropertiesRequest {\n");
+            sb.Append("  ").Append(base.ToString()?.Replace("\n", "\n  ")).Append("\n");
+            sb.Append("  SomeProperty: ").Append(SomeProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
+        {
+            return this.BaseValidate(validationContext);
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        protected IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> BaseValidate(ValidationContext validationContext)
+        {
+            yield break;
+        }
+    }
+
+    /// <summary>
+    /// A Json converter for type <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+    /// </summary>
+    public class TestInlineFreeformAdditionalPropertiesRequestJsonConverter : JsonConverter<TestInlineFreeformAdditionalPropertiesRequest>
+    {
+        /// <summary>
+        /// Deserializes json to <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="utf8JsonReader"></param>
+        /// <param name="typeToConvert"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <returns></returns>
+        /// <exception cref="JsonException"></exception>
+        public override TestInlineFreeformAdditionalPropertiesRequest Read(ref Utf8JsonReader utf8JsonReader, Type typeToConvert, JsonSerializerOptions jsonSerializerOptions)
+        {
+            int currentDepth = utf8JsonReader.CurrentDepth;
+
+            if (utf8JsonReader.TokenType != JsonTokenType.StartObject && utf8JsonReader.TokenType != JsonTokenType.StartArray)
+                throw new JsonException();
+
+            JsonTokenType startingTokenType = utf8JsonReader.TokenType;
+
+            string someProperty = default;
+
+            while (utf8JsonReader.Read())
+            {
+                if (startingTokenType == JsonTokenType.StartObject && utf8JsonReader.TokenType == JsonTokenType.EndObject && currentDepth == utf8JsonReader.CurrentDepth)
+                    break;
+
+                if (startingTokenType == JsonTokenType.StartArray && utf8JsonReader.TokenType == JsonTokenType.EndArray && currentDepth == utf8JsonReader.CurrentDepth)
+                    break;
+
+                if (utf8JsonReader.TokenType == JsonTokenType.PropertyName && currentDepth == utf8JsonReader.CurrentDepth - 1)
+                {
+                    string localVarJsonPropertyName = utf8JsonReader.GetString();
+                    utf8JsonReader.Read();
+
+                    switch (localVarJsonPropertyName)
+                    {
+                        case "someProperty":
+                            someProperty = utf8JsonReader.GetString();
+                            break;
+                        default:
+                            break;
+                    }
+                }
+            }
+
+            if (someProperty == null)
+                throw new ArgumentNullException(nameof(someProperty), "Property is required for class TestInlineFreeformAdditionalPropertiesRequest.");
+
+            return new TestInlineFreeformAdditionalPropertiesRequest(someProperty);
+        }
+
+        /// <summary>
+        /// Serializes a <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <exception cref="NotImplementedException"></exception>
+        public override void Write(Utf8JsonWriter writer, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, JsonSerializerOptions jsonSerializerOptions)
+        {
+            writer.WriteStartObject();
+
+            WriteProperties(ref writer, testInlineFreeformAdditionalPropertiesRequest, jsonSerializerOptions);
+            writer.WriteEndObject();
+        }
+
+        /// <summary>
+        /// Serializes the properties of <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <exception cref="NotImplementedException"></exception>
+        public void WriteProperties(ref Utf8JsonWriter writer, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, JsonSerializerOptions jsonSerializerOptions)
+        {
+            writer.WriteString("someProperty", testInlineFreeformAdditionalPropertiesRequest.SomeProperty);
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/.openapi-generator/FILES
@@ -91,6 +91,7 @@ docs/models/SpecialModelName.md
 docs/models/Tag.md
 docs/models/TestCollectionEndingWithWordList.md
 docs/models/TestCollectionEndingWithWordListObject.md
+docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/models/Triangle.md
 docs/models/TriangleInterface.md
 docs/models/User.md
@@ -217,6 +218,7 @@ src/Org.OpenAPITools/Model/SpecialModelName.cs
 src/Org.OpenAPITools/Model/Tag.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs
+src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/Org.OpenAPITools/Model/Triangle.cs
 src/Org.OpenAPITools/Model/TriangleInterface.cs
 src/Org.OpenAPITools/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/docs/apis/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/docs/apis/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1205,6 +1206,91 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../../README.md#documentation-for-api-endpoints) [[Back to Model list]](../../README.md#documentation-for-models) [[Back to README]](../../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            var apiInstance = new FakeApi(config);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/docs/models/TestInlineFreeformAdditionalPropertiesRequest.md
@@ -0,0 +1,10 @@
+# Org.OpenAPITools.Model.TestInlineFreeformAdditionalPropertiesRequest
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**SomeProperty** | **string** |  | [optional] 
+
+[[Back to Model list]](../../README.md#documentation-for-models) [[Back to API list]](../../README.md#documentation-for-api-endpoints) [[Back to README]](../../README.md)
+
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
@@ -0,0 +1,65 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using Xunit;
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using Org.OpenAPITools.Model;
+using Org.OpenAPITools.Client;
+using System.Reflection;
+
+namespace Org.OpenAPITools.Test.Model
+{
+    /// <summary>
+    ///  Class for testing TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class TestInlineFreeformAdditionalPropertiesRequestTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for TestInlineFreeformAdditionalPropertiesRequest
+        //private TestInlineFreeformAdditionalPropertiesRequest instance;
+
+        public TestInlineFreeformAdditionalPropertiesRequestTests()
+        {
+            // TODO uncomment below to create an instance of TestInlineFreeformAdditionalPropertiesRequest
+            //instance = new TestInlineFreeformAdditionalPropertiesRequest();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of TestInlineFreeformAdditionalPropertiesRequest
+        /// </summary>
+        [Fact]
+        public void TestInlineFreeformAdditionalPropertiesRequestInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" TestInlineFreeformAdditionalPropertiesRequest
+            //Assert.IsType<TestInlineFreeformAdditionalPropertiesRequest>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'SomeProperty'
+        /// </summary>
+        [Fact]
+        public void SomePropertyTest()
+        {
+            // TODO unit test for the property 'SomeProperty'
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/src/Org.OpenAPITools/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/src/Org.OpenAPITools/Api/FakeApi.cs
@@ -382,6 +382,29 @@ namespace Org.OpenAPITools.Api
        /// <returns>Task&lt;ApiResponse&gt;object&gt;&gt;</returns>
        Task<ApiResponse<object>> TestInlineAdditionalPropertiesOrDefaultAsync(Dictionary<string, string> requestBody, System.Threading.CancellationToken cancellationToken = default);

+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
+        Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default);
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task&lt;ApiResponse&gt;object&gt;&gt;</returns>
+        Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesOrDefaultAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default);
+
        /// <summary>
        /// test json serialization of form data
        /// </summary>
@@ -713,6 +736,26 @@ namespace Org.OpenAPITools.Api
            OnErrorTestInlineAdditionalProperties?.Invoke(this, new ExceptionEventArgs(exception));
        }

+        /// <summary>
+        /// The event raised after the server response
+        /// </summary>
+        public event EventHandler<ApiResponseEventArgs<object>> OnTestInlineFreeformAdditionalProperties;
+
+        /// <summary>
+        /// The event raised after an error querying the server
+        /// </summary>
+        public event EventHandler<ExceptionEventArgs> OnErrorTestInlineFreeformAdditionalProperties;
+
+        internal void ExecuteOnTestInlineFreeformAdditionalProperties(ApiResponse<object> apiResponse)
+        {
+            OnTestInlineFreeformAdditionalProperties?.Invoke(this, new ApiResponseEventArgs<object>(apiResponse));
+        }
+
+        internal void ExecuteOnErrorTestInlineFreeformAdditionalProperties(Exception exception)
+        {
+            OnErrorTestInlineFreeformAdditionalProperties?.Invoke(this, new ExceptionEventArgs(exception));
+        }
+
        /// <summary>
        /// The event raised after the server response
        /// </summary>
@@ -2936,6 +2979,148 @@ namespace Org.OpenAPITools.Api
            }
        }

+        partial void FormatTestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// Validates the request parameters
+        /// </summary>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <returns></returns>
+        private void ValidateTestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+                throw new ArgumentNullException(nameof(testInlineFreeformAdditionalPropertiesRequest));
+        }
+
+        /// <summary>
+        /// Processes the server response
+        /// </summary>
+        /// <param name="apiResponseLocalVar"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        private void AfterTestInlineFreeformAdditionalPropertiesDefaultImplementation(ApiResponse<object> apiResponseLocalVar, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            bool suppressDefaultLog = false;
+            AfterTestInlineFreeformAdditionalProperties(ref suppressDefaultLog, apiResponseLocalVar, testInlineFreeformAdditionalPropertiesRequest);
+            if (!suppressDefaultLog)
+                Logger.LogInformation("{0,-9} | {1} | {3}", (apiResponseLocalVar.DownloadedAt - apiResponseLocalVar.RequestedAt).TotalSeconds, apiResponseLocalVar.StatusCode, apiResponseLocalVar.Path);
+        }
+
+        /// <summary>
+        /// Processes the server response
+        /// </summary>
+        /// <param name="suppressDefaultLog"></param>
+        /// <param name="apiResponseLocalVar"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        partial void AfterTestInlineFreeformAdditionalProperties(ref bool suppressDefaultLog, ApiResponse<object> apiResponseLocalVar, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// Logs exceptions that occur while retrieving the server response
+        /// </summary>
+        /// <param name="exception"></param>
+        /// <param name="pathFormat"></param>
+        /// <param name="path"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        private void OnErrorTestInlineFreeformAdditionalPropertiesDefaultImplementation(Exception exception, string pathFormat, string path, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            bool suppressDefaultLog = false;
+            OnErrorTestInlineFreeformAdditionalProperties(ref suppressDefaultLog, exception, pathFormat, path, testInlineFreeformAdditionalPropertiesRequest);
+            if (!suppressDefaultLog)
+                Logger.LogError(exception, "An error occurred while sending the request to the server.");
+        }
+
+        /// <summary>
+        /// A partial method that gives developers a way to provide customized exception handling
+        /// </summary>
+        /// <param name="suppressDefaultLog"></param>
+        /// <param name="exception"></param>
+        /// <param name="pathFormat"></param>
+        /// <param name="path"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        partial void OnErrorTestInlineFreeformAdditionalProperties(ref bool suppressDefaultLog, Exception exception, string pathFormat, string path, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
+        public async Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesOrDefaultAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default)
+        {
+            try
+            {
+                return await TestInlineFreeformAdditionalPropertiesAsync(testInlineFreeformAdditionalPropertiesRequest, cancellationToken).ConfigureAwait(false);
+            }
+            catch (Exception)
+            {
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
+        public async Task<ApiResponse<object>> TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default)
+        {
+            UriBuilder uriBuilderLocalVar = new UriBuilder();
+
+            try
+            {
+                ValidateTestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+
+                FormatTestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+
+                using (HttpRequestMessage httpRequestMessageLocalVar = new HttpRequestMessage())
+                {
+                    uriBuilderLocalVar.Host = HttpClient.BaseAddress.Host;
+                    uriBuilderLocalVar.Port = HttpClient.BaseAddress.Port;
+                    uriBuilderLocalVar.Scheme = HttpClient.BaseAddress.Scheme;
+                    uriBuilderLocalVar.Path = ClientUtils.CONTEXT_PATH + "/fake/inline-freeform-additionalProperties";
+
+                    httpRequestMessageLocalVar.Content = (testInlineFreeformAdditionalPropertiesRequest as object) is System.IO.Stream stream
+                        ? httpRequestMessageLocalVar.Content = new StreamContent(stream)
+                        : httpRequestMessageLocalVar.Content = new StringContent(JsonSerializer.Serialize(testInlineFreeformAdditionalPropertiesRequest, _jsonSerializerOptions));
+
+                    httpRequestMessageLocalVar.RequestUri = uriBuilderLocalVar.Uri;
+
+                    string[] contentTypes = new string[] {
+                        "application/json"
+                    };
+
+                    string contentTypeLocalVar = ClientUtils.SelectHeaderContentType(contentTypes);
+
+                    if (contentTypeLocalVar != null && httpRequestMessageLocalVar.Content != null)
+                        httpRequestMessageLocalVar.Content.Headers.ContentType = new MediaTypeHeaderValue(contentTypeLocalVar);
+
+                    httpRequestMessageLocalVar.Method = new HttpMethod("POST");
+
+                    DateTime requestedAtLocalVar = DateTime.UtcNow;
+
+                    using (HttpResponseMessage httpResponseMessageLocalVar = await HttpClient.SendAsync(httpRequestMessageLocalVar, cancellationToken).ConfigureAwait(false))
+                    {
+                        string responseContentLocalVar = await httpResponseMessageLocalVar.Content.ReadAsStringAsync().ConfigureAwait(false);
+
+                        ApiResponse<object> apiResponseLocalVar = new ApiResponse<object>(httpRequestMessageLocalVar, httpResponseMessageLocalVar, responseContentLocalVar, "/fake/inline-freeform-additionalProperties", requestedAtLocalVar, _jsonSerializerOptions);
+
+                        AfterTestInlineFreeformAdditionalPropertiesDefaultImplementation(apiResponseLocalVar, testInlineFreeformAdditionalPropertiesRequest);
+
+                        Events.ExecuteOnTestInlineFreeformAdditionalProperties(apiResponseLocalVar);
+
+                        return apiResponseLocalVar;
+                    }
+                }
+            }
+            catch(Exception e)
+            {
+                OnErrorTestInlineFreeformAdditionalPropertiesDefaultImplementation(e, "/fake/inline-freeform-additionalProperties", uriBuilderLocalVar.Path, testInlineFreeformAdditionalPropertiesRequest);
+                Events.ExecuteOnErrorTestInlineFreeformAdditionalProperties(e);
+                throw;
+            }
+        }
+
        partial void FormatTestJsonFormData(ref string param, ref string param2);

        /// <summary>
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/src/Org.OpenAPITools/Client/HostConfiguration.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/src/Org.OpenAPITools/Client/HostConfiguration.cs
@@ -126,6 +126,7 @@ namespace Org.OpenAPITools.Client
            _jsonOptions.Converters.Add(new TagJsonConverter());
            _jsonOptions.Converters.Add(new TestCollectionEndingWithWordListJsonConverter());
            _jsonOptions.Converters.Add(new TestCollectionEndingWithWordListObjectJsonConverter());
+            _jsonOptions.Converters.Add(new TestInlineFreeformAdditionalPropertiesRequestJsonConverter());
            _jsonOptions.Converters.Add(new TriangleJsonConverter());
            _jsonOptions.Converters.Add(new TriangleInterfaceJsonConverter());
            _jsonOptions.Converters.Add(new UserJsonConverter());
--- a/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-generichost-netstandard2.0/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
@@ -0,0 +1,173 @@
+// <auto-generated>
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.ComponentModel.DataAnnotations;
+using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
+
+namespace Org.OpenAPITools.Model
+{
+    /// <summary>
+    /// TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    public partial class TestInlineFreeformAdditionalPropertiesRequest : Dictionary<String, Object>, IValidatableObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestInlineFreeformAdditionalPropertiesRequest" /> class.
+        /// </summary>
+        /// <param name="someProperty">someProperty</param>
+        [JsonConstructor]
+        public TestInlineFreeformAdditionalPropertiesRequest(string someProperty) : base()
+        {
+            SomeProperty = someProperty;
+            OnCreated();
+        }
+
+        partial void OnCreated();
+
+        /// <summary>
+        /// Gets or Sets SomeProperty
+        /// </summary>
+        [JsonPropertyName("someProperty")]
+        public string SomeProperty { get; set; }
+
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public Dictionary<string, JsonElement> AdditionalProperties { get; } = new Dictionary<string, JsonElement>();
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class TestInlineFreeformAdditionalPropertiesRequest {\n");
+            sb.Append("  ").Append(base.ToString()?.Replace("\n", "\n  ")).Append("\n");
+            sb.Append("  SomeProperty: ").Append(SomeProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
+        {
+            return this.BaseValidate(validationContext);
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        protected IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> BaseValidate(ValidationContext validationContext)
+        {
+            yield break;
+        }
+    }
+
+    /// <summary>
+    /// A Json converter for type <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+    /// </summary>
+    public class TestInlineFreeformAdditionalPropertiesRequestJsonConverter : JsonConverter<TestInlineFreeformAdditionalPropertiesRequest>
+    {
+        /// <summary>
+        /// Deserializes json to <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="utf8JsonReader"></param>
+        /// <param name="typeToConvert"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <returns></returns>
+        /// <exception cref="JsonException"></exception>
+        public override TestInlineFreeformAdditionalPropertiesRequest Read(ref Utf8JsonReader utf8JsonReader, Type typeToConvert, JsonSerializerOptions jsonSerializerOptions)
+        {
+            int currentDepth = utf8JsonReader.CurrentDepth;
+
+            if (utf8JsonReader.TokenType != JsonTokenType.StartObject && utf8JsonReader.TokenType != JsonTokenType.StartArray)
+                throw new JsonException();
+
+            JsonTokenType startingTokenType = utf8JsonReader.TokenType;
+
+            string someProperty = default;
+
+            while (utf8JsonReader.Read())
+            {
+                if (startingTokenType == JsonTokenType.StartObject && utf8JsonReader.TokenType == JsonTokenType.EndObject && currentDepth == utf8JsonReader.CurrentDepth)
+                    break;
+
+                if (startingTokenType == JsonTokenType.StartArray && utf8JsonReader.TokenType == JsonTokenType.EndArray && currentDepth == utf8JsonReader.CurrentDepth)
+                    break;
+
+                if (utf8JsonReader.TokenType == JsonTokenType.PropertyName && currentDepth == utf8JsonReader.CurrentDepth - 1)
+                {
+                    string localVarJsonPropertyName = utf8JsonReader.GetString();
+                    utf8JsonReader.Read();
+
+                    switch (localVarJsonPropertyName)
+                    {
+                        case "someProperty":
+                            someProperty = utf8JsonReader.GetString();
+                            break;
+                        default:
+                            break;
+                    }
+                }
+            }
+
+            if (someProperty == null)
+                throw new ArgumentNullException(nameof(someProperty), "Property is required for class TestInlineFreeformAdditionalPropertiesRequest.");
+
+            return new TestInlineFreeformAdditionalPropertiesRequest(someProperty);
+        }
+
+        /// <summary>
+        /// Serializes a <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <exception cref="NotImplementedException"></exception>
+        public override void Write(Utf8JsonWriter writer, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, JsonSerializerOptions jsonSerializerOptions)
+        {
+            writer.WriteStartObject();
+
+            WriteProperties(ref writer, testInlineFreeformAdditionalPropertiesRequest, jsonSerializerOptions);
+            writer.WriteEndObject();
+        }
+
+        /// <summary>
+        /// Serializes the properties of <see cref="TestInlineFreeformAdditionalPropertiesRequest" />
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest"></param>
+        /// <param name="jsonSerializerOptions"></param>
+        /// <exception cref="NotImplementedException"></exception>
+        public void WriteProperties(ref Utf8JsonWriter writer, TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, JsonSerializerOptions jsonSerializerOptions)
+        {
+            writer.WriteString("someProperty", testInlineFreeformAdditionalPropertiesRequest.SomeProperty);
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-httpclient/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient-httpclient/.openapi-generator/FILES
@@ -90,6 +90,7 @@ docs/StoreApi.md
 docs/Tag.md
 docs/TestCollectionEndingWithWordList.md
 docs/TestCollectionEndingWithWordListObject.md
+docs/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/Triangle.md
 docs/TriangleInterface.md
 docs/User.md
@@ -206,6 +207,7 @@ src/Org.OpenAPITools/Model/SpecialModelName.cs
 src/Org.OpenAPITools/Model/Tag.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs
+src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/Org.OpenAPITools/Model/Triangle.cs
 src/Org.OpenAPITools/Model/TriangleInterface.cs
 src/Org.OpenAPITools/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient-httpclient/README.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-httpclient/README.md
@@ -147,6 +147,7 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**TestEnumParameters**](docs/FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters
 *FakeApi* | [**TestGroupParameters**](docs/FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional)
 *FakeApi* | [**TestInlineAdditionalProperties**](docs/FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties
+*FakeApi* | [**TestInlineFreeformAdditionalProperties**](docs/FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties
 *FakeApi* | [**TestJsonFormData**](docs/FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data
 *FakeApi* | [**TestQueryParameterCollectionFormat**](docs/FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters | 
 *FakeClassnameTags123Api* | [**TestClassname**](docs/FakeClassnameTags123Api.md#testclassname) | **PATCH** /fake_classname_test | To test class name in snake case
@@ -257,6 +258,7 @@ Class | Method | HTTP request | Description
 - [Model.Tag](docs/Tag.md)
 - [Model.TestCollectionEndingWithWordList](docs/TestCollectionEndingWithWordList.md)
 - [Model.TestCollectionEndingWithWordListObject](docs/TestCollectionEndingWithWordListObject.md)
+ - [Model.TestInlineFreeformAdditionalPropertiesRequest](docs/TestInlineFreeformAdditionalPropertiesRequest.md)
 - [Model.Triangle](docs/Triangle.md)
 - [Model.TriangleInterface](docs/TriangleInterface.md)
 - [Model.User](docs/User.md)
--- a/samples/client/petstore/csharp/OpenAPIClient-httpclient/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient-httpclient/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient-httpclient/docs/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-httpclient/docs/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1257,6 +1258,95 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Net.Http;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            // create instances of HttpClient, HttpClientHandler to be reused later with different Api classes
+            HttpClient httpClient = new HttpClient();
+            HttpClientHandler httpClientHandler = new HttpClientHandler();
+            var apiInstance = new FakeApi(httpClient, config, httpClientHandler);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/samples/client/petstore/csharp/OpenAPIClient-httpclient/docs/TestInlineFreeformAdditionalPropertiesRequest.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-httpclient/docs/TestInlineFreeformAdditionalPropertiesRequest.md
@@ -0,0 +1,10 @@
+# Org.OpenAPITools.Model.TestInlineFreeformAdditionalPropertiesRequest
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**SomeProperty** | **string** |  | [optional] 
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
--- a/samples/client/petstore/csharp/OpenAPIClient-httpclient/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-httpclient/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
@@ -0,0 +1,66 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using Xunit;
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using Org.OpenAPITools.Model;
+using Org.OpenAPITools.Client;
+using System.Reflection;
+using Newtonsoft.Json;
+
+namespace Org.OpenAPITools.Test.Model
+{
+    /// <summary>
+    ///  Class for testing TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class TestInlineFreeformAdditionalPropertiesRequestTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for TestInlineFreeformAdditionalPropertiesRequest
+        //private TestInlineFreeformAdditionalPropertiesRequest instance;
+
+        public TestInlineFreeformAdditionalPropertiesRequestTests()
+        {
+            // TODO uncomment below to create an instance of TestInlineFreeformAdditionalPropertiesRequest
+            //instance = new TestInlineFreeformAdditionalPropertiesRequest();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of TestInlineFreeformAdditionalPropertiesRequest
+        /// </summary>
+        [Fact]
+        public void TestInlineFreeformAdditionalPropertiesRequestInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" TestInlineFreeformAdditionalPropertiesRequest
+            //Assert.IsType<TestInlineFreeformAdditionalPropertiesRequest>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'SomeProperty'
+        /// </summary>
+        [Fact]
+        public void SomePropertyTest()
+        {
+            // TODO unit test for the property 'SomeProperty'
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-httpclient/src/Org.OpenAPITools/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-httpclient/src/Org.OpenAPITools/Api/FakeApi.cs
@@ -339,6 +339,24 @@ namespace Org.OpenAPITools.Api
        /// <returns>ApiResponse of Object(void)</returns>
        ApiResponse<Object> TestInlineAdditionalPropertiesWithHttpInfo(Dictionary<string, string> requestBody);
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <returns></returns>
+        void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
@@ -754,6 +772,29 @@ namespace Org.OpenAPITools.Api
        /// <returns>Task of ApiResponse</returns>
        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineAdditionalPropertiesWithHttpInfoAsync(Dictionary<string, string> requestBody, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <remarks>
@@ -2773,6 +2814,119 @@ namespace Org.OpenAPITools.Api
            return localVarResponse;
        }

+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <returns></returns>
+        public void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        public Org.OpenAPITools.Client.ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null) localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null) localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+
+            // make the HTTP request
+            var localVarResponse = this.Client.Post<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration);
+
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null) throw _exception;
+            }
+
+            return localVarResponse;
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        public async System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            await TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(testInlineFreeformAdditionalPropertiesRequest, cancellationToken).ConfigureAwait(false);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        public async System.Threading.Tasks.Task<Org.OpenAPITools.Client.ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null) localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null) localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+
+            // make the HTTP request
+
+            var localVarResponse = await this.AsynchronousClient.PostAsync<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration, cancellationToken).ConfigureAwait(false);
+
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null) throw _exception;
+            }
+
+            return localVarResponse;
+        }
+
        /// <summary>
        /// test json serialization of form data 
        /// </summary>
--- a/samples/client/petstore/csharp/OpenAPIClient-httpclient/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-httpclient/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
@@ -0,0 +1,144 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Text.RegularExpressions;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+using Newtonsoft.Json.Linq;
+using System.ComponentModel.DataAnnotations;
+using FileParameter = Org.OpenAPITools.Client.FileParameter;
+using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
+using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
+
+namespace Org.OpenAPITools.Model
+{
+    /// <summary>
+    /// TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    [DataContract(Name = "testInlineFreeformAdditionalProperties_request")]
+    public partial class TestInlineFreeformAdditionalPropertiesRequest : Dictionary<String, Object>, IEquatable<TestInlineFreeformAdditionalPropertiesRequest>, IValidatableObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestInlineFreeformAdditionalPropertiesRequest" /> class.
+        /// </summary>
+        /// <param name="someProperty">someProperty.</param>
+        public TestInlineFreeformAdditionalPropertiesRequest(string someProperty = default(string)) : base()
+        {
+            this.SomeProperty = someProperty;
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
+
+        /// <summary>
+        /// Gets or Sets SomeProperty
+        /// </summary>
+        [DataMember(Name = "someProperty", EmitDefaultValue = false)]
+        public string SomeProperty { get; set; }
+
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class TestInlineFreeformAdditionalPropertiesRequest {\n");
+            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
+            sb.Append("  SomeProperty: ").Append(SomeProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return Newtonsoft.Json.JsonConvert.SerializeObject(this, Newtonsoft.Json.Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="input">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object input)
+        {
+            return OpenAPIClientUtils.compareLogic.Compare(this, input as TestInlineFreeformAdditionalPropertiesRequest).AreEqual;
+        }
+
+        /// <summary>
+        /// Returns true if TestInlineFreeformAdditionalPropertiesRequest instances are equal
+        /// </summary>
+        /// <param name="input">Instance of TestInlineFreeformAdditionalPropertiesRequest to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestInlineFreeformAdditionalPropertiesRequest input)
+        {
+            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                int hashCode = base.GetHashCode();
+                if (this.SomeProperty != null)
+                {
+                    hashCode = (hashCode * 59) + this.SomeProperty.GetHashCode();
+                }
+                if (this.AdditionalProperties != null)
+                {
+                    hashCode = (hashCode * 59) + this.AdditionalProperties.GetHashCode();
+                }
+                return hashCode;
+            }
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
+        {
+            return this.BaseValidate(validationContext);
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        protected IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> BaseValidate(ValidationContext validationContext)
+        {
+            yield break;
+        }
+    }
+
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-net47/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient-net47/.openapi-generator/FILES
@@ -90,6 +90,7 @@ docs/StoreApi.md
 docs/Tag.md
 docs/TestCollectionEndingWithWordList.md
 docs/TestCollectionEndingWithWordListObject.md
+docs/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/Triangle.md
 docs/TriangleInterface.md
 docs/User.md
@@ -209,6 +210,7 @@ src/Org.OpenAPITools/Model/SpecialModelName.cs
 src/Org.OpenAPITools/Model/Tag.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs
+src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/Org.OpenAPITools/Model/Triangle.cs
 src/Org.OpenAPITools/Model/TriangleInterface.cs
 src/Org.OpenAPITools/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient-net47/README.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-net47/README.md
@@ -134,6 +134,7 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**TestEnumParameters**](docs/FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters
 *FakeApi* | [**TestGroupParameters**](docs/FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional)
 *FakeApi* | [**TestInlineAdditionalProperties**](docs/FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties
+*FakeApi* | [**TestInlineFreeformAdditionalProperties**](docs/FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties
 *FakeApi* | [**TestJsonFormData**](docs/FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data
 *FakeApi* | [**TestQueryParameterCollectionFormat**](docs/FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters | 
 *FakeClassnameTags123Api* | [**TestClassname**](docs/FakeClassnameTags123Api.md#testclassname) | **PATCH** /fake_classname_test | To test class name in snake case
@@ -244,6 +245,7 @@ Class | Method | HTTP request | Description
 - [Model.Tag](docs/Tag.md)
 - [Model.TestCollectionEndingWithWordList](docs/TestCollectionEndingWithWordList.md)
 - [Model.TestCollectionEndingWithWordListObject](docs/TestCollectionEndingWithWordListObject.md)
+ - [Model.TestInlineFreeformAdditionalPropertiesRequest](docs/TestInlineFreeformAdditionalPropertiesRequest.md)
 - [Model.Triangle](docs/Triangle.md)
 - [Model.TriangleInterface](docs/TriangleInterface.md)
 - [Model.User](docs/User.md)
--- a/samples/client/petstore/csharp/OpenAPIClient-net47/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient-net47/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient-net47/docs/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-net47/docs/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1205,6 +1206,91 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            var apiInstance = new FakeApi(config);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/samples/client/petstore/csharp/OpenAPIClient-net47/docs/TestInlineFreeformAdditionalPropertiesRequest.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-net47/docs/TestInlineFreeformAdditionalPropertiesRequest.md
@@ -0,0 +1,10 @@
+# Org.OpenAPITools.Model.TestInlineFreeformAdditionalPropertiesRequest
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**SomeProperty** | **string** |  | [optional] 
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
--- a/samples/client/petstore/csharp/OpenAPIClient-net47/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net47/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
@@ -0,0 +1,66 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using Xunit;
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using Org.OpenAPITools.Model;
+using Org.OpenAPITools.Client;
+using System.Reflection;
+using Newtonsoft.Json;
+
+namespace Org.OpenAPITools.Test.Model
+{
+    /// <summary>
+    ///  Class for testing TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class TestInlineFreeformAdditionalPropertiesRequestTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for TestInlineFreeformAdditionalPropertiesRequest
+        //private TestInlineFreeformAdditionalPropertiesRequest instance;
+
+        public TestInlineFreeformAdditionalPropertiesRequestTests()
+        {
+            // TODO uncomment below to create an instance of TestInlineFreeformAdditionalPropertiesRequest
+            //instance = new TestInlineFreeformAdditionalPropertiesRequest();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of TestInlineFreeformAdditionalPropertiesRequest
+        /// </summary>
+        [Fact]
+        public void TestInlineFreeformAdditionalPropertiesRequestInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" TestInlineFreeformAdditionalPropertiesRequest
+            //Assert.IsType<TestInlineFreeformAdditionalPropertiesRequest>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'SomeProperty'
+        /// </summary>
+        [Fact]
+        public void SomePropertyTest()
+        {
+            // TODO unit test for the property 'SomeProperty'
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-net47/src/Org.OpenAPITools/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net47/src/Org.OpenAPITools/Api/FakeApi.cs
@@ -365,6 +365,26 @@ namespace Org.OpenAPITools.Api
        /// <returns>ApiResponse of Object(void)</returns>
        ApiResponse<Object> TestInlineAdditionalPropertiesWithHttpInfo(Dictionary<string, string> requestBody, int operationIndex = 0);
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns></returns>
+        void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0);
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0);
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
@@ -810,6 +830,31 @@ namespace Org.OpenAPITools.Api
        /// <returns>Task of ApiResponse</returns>
        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineAdditionalPropertiesWithHttpInfoAsync(Dictionary<string, string> requestBody, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <remarks>
@@ -3093,6 +3138,148 @@ namespace Org.OpenAPITools.Api
            return localVarResponse;
        }

+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns></returns>
+        public void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0)
+        {
+            TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        public Org.OpenAPITools.Client.ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0)
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+            {
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+            }
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+            }
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+            }
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+            localVarRequestOptions.Operation = "FakeApi.TestInlineFreeformAdditionalProperties";
+            localVarRequestOptions.OperationIndex = operationIndex;
+
+
+            // make the HTTP request
+            var localVarResponse = this.Client.Post<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration);
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null)
+                {
+                    throw _exception;
+                }
+            }
+
+            return localVarResponse;
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        public async System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            await TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(testInlineFreeformAdditionalPropertiesRequest, operationIndex, cancellationToken).ConfigureAwait(false);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        public async System.Threading.Tasks.Task<Org.OpenAPITools.Client.ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+            {
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+            }
+
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+            }
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+            }
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+            localVarRequestOptions.Operation = "FakeApi.TestInlineFreeformAdditionalProperties";
+            localVarRequestOptions.OperationIndex = operationIndex;
+
+
+            // make the HTTP request
+            var localVarResponse = await this.AsynchronousClient.PostAsync<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration, cancellationToken).ConfigureAwait(false);
+
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null)
+                {
+                    throw _exception;
+                }
+            }
+
+            return localVarResponse;
+        }
+
        /// <summary>
        /// test json serialization of form data 
        /// </summary>
--- a/samples/client/petstore/csharp/OpenAPIClient-net47/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net47/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
@@ -0,0 +1,143 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Text.RegularExpressions;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+using Newtonsoft.Json.Linq;
+using System.ComponentModel.DataAnnotations;
+using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
+using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
+
+namespace Org.OpenAPITools.Model
+{
+    /// <summary>
+    /// TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    [DataContract(Name = "testInlineFreeformAdditionalProperties_request")]
+    public partial class TestInlineFreeformAdditionalPropertiesRequest : Dictionary<String, Object>, IEquatable<TestInlineFreeformAdditionalPropertiesRequest>, IValidatableObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestInlineFreeformAdditionalPropertiesRequest" /> class.
+        /// </summary>
+        /// <param name="someProperty">someProperty.</param>
+        public TestInlineFreeformAdditionalPropertiesRequest(string someProperty = default(string)) : base()
+        {
+            this.SomeProperty = someProperty;
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
+
+        /// <summary>
+        /// Gets or Sets SomeProperty
+        /// </summary>
+        [DataMember(Name = "someProperty", EmitDefaultValue = false)]
+        public string SomeProperty { get; set; }
+
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class TestInlineFreeformAdditionalPropertiesRequest {\n");
+            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
+            sb.Append("  SomeProperty: ").Append(SomeProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return Newtonsoft.Json.JsonConvert.SerializeObject(this, Newtonsoft.Json.Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="input">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object input)
+        {
+            return OpenAPIClientUtils.compareLogic.Compare(this, input as TestInlineFreeformAdditionalPropertiesRequest).AreEqual;
+        }
+
+        /// <summary>
+        /// Returns true if TestInlineFreeformAdditionalPropertiesRequest instances are equal
+        /// </summary>
+        /// <param name="input">Instance of TestInlineFreeformAdditionalPropertiesRequest to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestInlineFreeformAdditionalPropertiesRequest input)
+        {
+            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                int hashCode = base.GetHashCode();
+                if (this.SomeProperty != null)
+                {
+                    hashCode = (hashCode * 59) + this.SomeProperty.GetHashCode();
+                }
+                if (this.AdditionalProperties != null)
+                {
+                    hashCode = (hashCode * 59) + this.AdditionalProperties.GetHashCode();
+                }
+                return hashCode;
+            }
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
+        {
+            return this.BaseValidate(validationContext);
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        protected IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> BaseValidate(ValidationContext validationContext)
+        {
+            yield break;
+        }
+    }
+
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-net48/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient-net48/.openapi-generator/FILES
@@ -90,6 +90,7 @@ docs/StoreApi.md
 docs/Tag.md
 docs/TestCollectionEndingWithWordList.md
 docs/TestCollectionEndingWithWordListObject.md
+docs/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/Triangle.md
 docs/TriangleInterface.md
 docs/User.md
@@ -209,6 +210,7 @@ src/Org.OpenAPITools/Model/SpecialModelName.cs
 src/Org.OpenAPITools/Model/Tag.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs
+src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/Org.OpenAPITools/Model/Triangle.cs
 src/Org.OpenAPITools/Model/TriangleInterface.cs
 src/Org.OpenAPITools/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient-net48/README.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-net48/README.md
@@ -134,6 +134,7 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**TestEnumParameters**](docs/FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters
 *FakeApi* | [**TestGroupParameters**](docs/FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional)
 *FakeApi* | [**TestInlineAdditionalProperties**](docs/FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties
+*FakeApi* | [**TestInlineFreeformAdditionalProperties**](docs/FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties
 *FakeApi* | [**TestJsonFormData**](docs/FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data
 *FakeApi* | [**TestQueryParameterCollectionFormat**](docs/FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters | 
 *FakeClassnameTags123Api* | [**TestClassname**](docs/FakeClassnameTags123Api.md#testclassname) | **PATCH** /fake_classname_test | To test class name in snake case
@@ -244,6 +245,7 @@ Class | Method | HTTP request | Description
 - [Model.Tag](docs/Tag.md)
 - [Model.TestCollectionEndingWithWordList](docs/TestCollectionEndingWithWordList.md)
 - [Model.TestCollectionEndingWithWordListObject](docs/TestCollectionEndingWithWordListObject.md)
+ - [Model.TestInlineFreeformAdditionalPropertiesRequest](docs/TestInlineFreeformAdditionalPropertiesRequest.md)
 - [Model.Triangle](docs/Triangle.md)
 - [Model.TriangleInterface](docs/TriangleInterface.md)
 - [Model.User](docs/User.md)
--- a/samples/client/petstore/csharp/OpenAPIClient-net48/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient-net48/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient-net48/docs/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-net48/docs/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1205,6 +1206,91 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            var apiInstance = new FakeApi(config);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/samples/client/petstore/csharp/OpenAPIClient-net48/docs/TestInlineFreeformAdditionalPropertiesRequest.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-net48/docs/TestInlineFreeformAdditionalPropertiesRequest.md
@@ -0,0 +1,10 @@
+# Org.OpenAPITools.Model.TestInlineFreeformAdditionalPropertiesRequest
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**SomeProperty** | **string** |  | [optional] 
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
--- a/samples/client/petstore/csharp/OpenAPIClient-net48/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net48/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
@@ -0,0 +1,66 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using Xunit;
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using Org.OpenAPITools.Model;
+using Org.OpenAPITools.Client;
+using System.Reflection;
+using Newtonsoft.Json;
+
+namespace Org.OpenAPITools.Test.Model
+{
+    /// <summary>
+    ///  Class for testing TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class TestInlineFreeformAdditionalPropertiesRequestTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for TestInlineFreeformAdditionalPropertiesRequest
+        //private TestInlineFreeformAdditionalPropertiesRequest instance;
+
+        public TestInlineFreeformAdditionalPropertiesRequestTests()
+        {
+            // TODO uncomment below to create an instance of TestInlineFreeformAdditionalPropertiesRequest
+            //instance = new TestInlineFreeformAdditionalPropertiesRequest();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of TestInlineFreeformAdditionalPropertiesRequest
+        /// </summary>
+        [Fact]
+        public void TestInlineFreeformAdditionalPropertiesRequestInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" TestInlineFreeformAdditionalPropertiesRequest
+            //Assert.IsType<TestInlineFreeformAdditionalPropertiesRequest>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'SomeProperty'
+        /// </summary>
+        [Fact]
+        public void SomePropertyTest()
+        {
+            // TODO unit test for the property 'SomeProperty'
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-net48/src/Org.OpenAPITools/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net48/src/Org.OpenAPITools/Api/FakeApi.cs
@@ -365,6 +365,26 @@ namespace Org.OpenAPITools.Api
        /// <returns>ApiResponse of Object(void)</returns>
        ApiResponse<Object> TestInlineAdditionalPropertiesWithHttpInfo(Dictionary<string, string> requestBody, int operationIndex = 0);
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns></returns>
+        void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0);
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0);
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
@@ -810,6 +830,31 @@ namespace Org.OpenAPITools.Api
        /// <returns>Task of ApiResponse</returns>
        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineAdditionalPropertiesWithHttpInfoAsync(Dictionary<string, string> requestBody, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <remarks>
@@ -3093,6 +3138,148 @@ namespace Org.OpenAPITools.Api
            return localVarResponse;
        }

+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns></returns>
+        public void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0)
+        {
+            TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        public Org.OpenAPITools.Client.ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0)
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+            {
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+            }
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+            }
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+            }
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+            localVarRequestOptions.Operation = "FakeApi.TestInlineFreeformAdditionalProperties";
+            localVarRequestOptions.OperationIndex = operationIndex;
+
+
+            // make the HTTP request
+            var localVarResponse = this.Client.Post<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration);
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null)
+                {
+                    throw _exception;
+                }
+            }
+
+            return localVarResponse;
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        public async System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            await TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(testInlineFreeformAdditionalPropertiesRequest, operationIndex, cancellationToken).ConfigureAwait(false);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        public async System.Threading.Tasks.Task<Org.OpenAPITools.Client.ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+            {
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+            }
+
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+            }
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+            }
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+            localVarRequestOptions.Operation = "FakeApi.TestInlineFreeformAdditionalProperties";
+            localVarRequestOptions.OperationIndex = operationIndex;
+
+
+            // make the HTTP request
+            var localVarResponse = await this.AsynchronousClient.PostAsync<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration, cancellationToken).ConfigureAwait(false);
+
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null)
+                {
+                    throw _exception;
+                }
+            }
+
+            return localVarResponse;
+        }
+
        /// <summary>
        /// test json serialization of form data 
        /// </summary>
--- a/samples/client/petstore/csharp/OpenAPIClient-net48/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net48/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
@@ -0,0 +1,143 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Text.RegularExpressions;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+using Newtonsoft.Json.Linq;
+using System.ComponentModel.DataAnnotations;
+using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
+using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
+
+namespace Org.OpenAPITools.Model
+{
+    /// <summary>
+    /// TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    [DataContract(Name = "testInlineFreeformAdditionalProperties_request")]
+    public partial class TestInlineFreeformAdditionalPropertiesRequest : Dictionary<String, Object>, IEquatable<TestInlineFreeformAdditionalPropertiesRequest>, IValidatableObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestInlineFreeformAdditionalPropertiesRequest" /> class.
+        /// </summary>
+        /// <param name="someProperty">someProperty.</param>
+        public TestInlineFreeformAdditionalPropertiesRequest(string someProperty = default(string)) : base()
+        {
+            this.SomeProperty = someProperty;
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
+
+        /// <summary>
+        /// Gets or Sets SomeProperty
+        /// </summary>
+        [DataMember(Name = "someProperty", EmitDefaultValue = false)]
+        public string SomeProperty { get; set; }
+
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class TestInlineFreeformAdditionalPropertiesRequest {\n");
+            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
+            sb.Append("  SomeProperty: ").Append(SomeProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return Newtonsoft.Json.JsonConvert.SerializeObject(this, Newtonsoft.Json.Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="input">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object input)
+        {
+            return OpenAPIClientUtils.compareLogic.Compare(this, input as TestInlineFreeformAdditionalPropertiesRequest).AreEqual;
+        }
+
+        /// <summary>
+        /// Returns true if TestInlineFreeformAdditionalPropertiesRequest instances are equal
+        /// </summary>
+        /// <param name="input">Instance of TestInlineFreeformAdditionalPropertiesRequest to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestInlineFreeformAdditionalPropertiesRequest input)
+        {
+            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                int hashCode = base.GetHashCode();
+                if (this.SomeProperty != null)
+                {
+                    hashCode = (hashCode * 59) + this.SomeProperty.GetHashCode();
+                }
+                if (this.AdditionalProperties != null)
+                {
+                    hashCode = (hashCode * 59) + this.AdditionalProperties.GetHashCode();
+                }
+                return hashCode;
+            }
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
+        {
+            return this.BaseValidate(validationContext);
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        protected IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> BaseValidate(ValidationContext validationContext)
+        {
+            yield break;
+        }
+    }
+
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-net5.0/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient-net5.0/.openapi-generator/FILES
@@ -90,6 +90,7 @@ docs/StoreApi.md
 docs/Tag.md
 docs/TestCollectionEndingWithWordList.md
 docs/TestCollectionEndingWithWordListObject.md
+docs/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/Triangle.md
 docs/TriangleInterface.md
 docs/User.md
@@ -209,6 +210,7 @@ src/Org.OpenAPITools/Model/SpecialModelName.cs
 src/Org.OpenAPITools/Model/Tag.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs
+src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/Org.OpenAPITools/Model/Triangle.cs
 src/Org.OpenAPITools/Model/TriangleInterface.cs
 src/Org.OpenAPITools/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient-net5.0/README.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-net5.0/README.md
@@ -134,6 +134,7 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**TestEnumParameters**](docs/FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters
 *FakeApi* | [**TestGroupParameters**](docs/FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional)
 *FakeApi* | [**TestInlineAdditionalProperties**](docs/FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties
+*FakeApi* | [**TestInlineFreeformAdditionalProperties**](docs/FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties
 *FakeApi* | [**TestJsonFormData**](docs/FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data
 *FakeApi* | [**TestQueryParameterCollectionFormat**](docs/FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters | 
 *FakeClassnameTags123Api* | [**TestClassname**](docs/FakeClassnameTags123Api.md#testclassname) | **PATCH** /fake_classname_test | To test class name in snake case
@@ -244,6 +245,7 @@ Class | Method | HTTP request | Description
 - [Model.Tag](docs/Tag.md)
 - [Model.TestCollectionEndingWithWordList](docs/TestCollectionEndingWithWordList.md)
 - [Model.TestCollectionEndingWithWordListObject](docs/TestCollectionEndingWithWordListObject.md)
+ - [Model.TestInlineFreeformAdditionalPropertiesRequest](docs/TestInlineFreeformAdditionalPropertiesRequest.md)
 - [Model.Triangle](docs/Triangle.md)
 - [Model.TriangleInterface](docs/TriangleInterface.md)
 - [Model.User](docs/User.md)
--- a/samples/client/petstore/csharp/OpenAPIClient-net5.0/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient-net5.0/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient-net5.0/docs/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-net5.0/docs/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1205,6 +1206,91 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            var apiInstance = new FakeApi(config);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/samples/client/petstore/csharp/OpenAPIClient-net5.0/docs/TestInlineFreeformAdditionalPropertiesRequest.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-net5.0/docs/TestInlineFreeformAdditionalPropertiesRequest.md
@@ -0,0 +1,10 @@
+# Org.OpenAPITools.Model.TestInlineFreeformAdditionalPropertiesRequest
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**SomeProperty** | **string** |  | [optional] 
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
--- a/samples/client/petstore/csharp/OpenAPIClient-net5.0/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net5.0/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
@@ -0,0 +1,66 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using Xunit;
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using Org.OpenAPITools.Model;
+using Org.OpenAPITools.Client;
+using System.Reflection;
+using Newtonsoft.Json;
+
+namespace Org.OpenAPITools.Test.Model
+{
+    /// <summary>
+    ///  Class for testing TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class TestInlineFreeformAdditionalPropertiesRequestTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for TestInlineFreeformAdditionalPropertiesRequest
+        //private TestInlineFreeformAdditionalPropertiesRequest instance;
+
+        public TestInlineFreeformAdditionalPropertiesRequestTests()
+        {
+            // TODO uncomment below to create an instance of TestInlineFreeformAdditionalPropertiesRequest
+            //instance = new TestInlineFreeformAdditionalPropertiesRequest();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of TestInlineFreeformAdditionalPropertiesRequest
+        /// </summary>
+        [Fact]
+        public void TestInlineFreeformAdditionalPropertiesRequestInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" TestInlineFreeformAdditionalPropertiesRequest
+            //Assert.IsType<TestInlineFreeformAdditionalPropertiesRequest>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'SomeProperty'
+        /// </summary>
+        [Fact]
+        public void SomePropertyTest()
+        {
+            // TODO unit test for the property 'SomeProperty'
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-net5.0/src/Org.OpenAPITools/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net5.0/src/Org.OpenAPITools/Api/FakeApi.cs
@@ -365,6 +365,26 @@ namespace Org.OpenAPITools.Api
        /// <returns>ApiResponse of Object(void)</returns>
        ApiResponse<Object> TestInlineAdditionalPropertiesWithHttpInfo(Dictionary<string, string> requestBody, int operationIndex = 0);
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns></returns>
+        void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0);
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0);
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
@@ -810,6 +830,31 @@ namespace Org.OpenAPITools.Api
        /// <returns>Task of ApiResponse</returns>
        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineAdditionalPropertiesWithHttpInfoAsync(Dictionary<string, string> requestBody, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <remarks>
@@ -3093,6 +3138,148 @@ namespace Org.OpenAPITools.Api
            return localVarResponse;
        }

+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns></returns>
+        public void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0)
+        {
+            TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        public Org.OpenAPITools.Client.ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0)
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+            {
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+            }
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+            }
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+            }
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+            localVarRequestOptions.Operation = "FakeApi.TestInlineFreeformAdditionalProperties";
+            localVarRequestOptions.OperationIndex = operationIndex;
+
+
+            // make the HTTP request
+            var localVarResponse = this.Client.Post<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration);
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null)
+                {
+                    throw _exception;
+                }
+            }
+
+            return localVarResponse;
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        public async System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            await TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(testInlineFreeformAdditionalPropertiesRequest, operationIndex, cancellationToken).ConfigureAwait(false);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="operationIndex">Index associated with the operation.</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        public async System.Threading.Tasks.Task<Org.OpenAPITools.Client.ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, int operationIndex = 0, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+            {
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+            }
+
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+            }
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null)
+            {
+                localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+            }
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+            localVarRequestOptions.Operation = "FakeApi.TestInlineFreeformAdditionalProperties";
+            localVarRequestOptions.OperationIndex = operationIndex;
+
+
+            // make the HTTP request
+            var localVarResponse = await this.AsynchronousClient.PostAsync<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration, cancellationToken).ConfigureAwait(false);
+
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null)
+                {
+                    throw _exception;
+                }
+            }
+
+            return localVarResponse;
+        }
+
        /// <summary>
        /// test json serialization of form data 
        /// </summary>
--- a/samples/client/petstore/csharp/OpenAPIClient-net5.0/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-net5.0/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
@@ -0,0 +1,143 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Text.RegularExpressions;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+using Newtonsoft.Json.Linq;
+using System.ComponentModel.DataAnnotations;
+using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
+using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
+
+namespace Org.OpenAPITools.Model
+{
+    /// <summary>
+    /// TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    [DataContract(Name = "testInlineFreeformAdditionalProperties_request")]
+    public partial class TestInlineFreeformAdditionalPropertiesRequest : Dictionary<String, Object>, IEquatable<TestInlineFreeformAdditionalPropertiesRequest>, IValidatableObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestInlineFreeformAdditionalPropertiesRequest" /> class.
+        /// </summary>
+        /// <param name="someProperty">someProperty.</param>
+        public TestInlineFreeformAdditionalPropertiesRequest(string someProperty = default(string)) : base()
+        {
+            this.SomeProperty = someProperty;
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
+
+        /// <summary>
+        /// Gets or Sets SomeProperty
+        /// </summary>
+        [DataMember(Name = "someProperty", EmitDefaultValue = false)]
+        public string SomeProperty { get; set; }
+
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class TestInlineFreeformAdditionalPropertiesRequest {\n");
+            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
+            sb.Append("  SomeProperty: ").Append(SomeProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return Newtonsoft.Json.JsonConvert.SerializeObject(this, Newtonsoft.Json.Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="input">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object input)
+        {
+            return OpenAPIClientUtils.compareLogic.Compare(this, input as TestInlineFreeformAdditionalPropertiesRequest).AreEqual;
+        }
+
+        /// <summary>
+        /// Returns true if TestInlineFreeformAdditionalPropertiesRequest instances are equal
+        /// </summary>
+        /// <param name="input">Instance of TestInlineFreeformAdditionalPropertiesRequest to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestInlineFreeformAdditionalPropertiesRequest input)
+        {
+            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                int hashCode = base.GetHashCode();
+                if (this.SomeProperty != null)
+                {
+                    hashCode = (hashCode * 59) + this.SomeProperty.GetHashCode();
+                }
+                if (this.AdditionalProperties != null)
+                {
+                    hashCode = (hashCode * 59) + this.AdditionalProperties.GetHashCode();
+                }
+                return hashCode;
+            }
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
+        {
+            return this.BaseValidate(validationContext);
+        }
+
+        /// <summary>
+        /// To validate all properties of the instance
+        /// </summary>
+        /// <param name="validationContext">Validation context</param>
+        /// <returns>Validation Result</returns>
+        protected IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> BaseValidate(ValidationContext validationContext)
+        {
+            yield break;
+        }
+    }
+
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/.openapi-generator/FILES
@@ -88,6 +88,7 @@ docs/StoreApi.md
 docs/Tag.md
 docs/TestCollectionEndingWithWordList.md
 docs/TestCollectionEndingWithWordListObject.md
+docs/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/Triangle.md
 docs/TriangleInterface.md
 docs/User.md
@@ -205,6 +206,7 @@ src/Org.OpenAPITools/Model/SpecialModelName.cs
 src/Org.OpenAPITools/Model/Tag.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs
+src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/Org.OpenAPITools/Model/Triangle.cs
 src/Org.OpenAPITools/Model/TriangleInterface.cs
 src/Org.OpenAPITools/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/README.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/README.md
@@ -108,6 +108,7 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters
 *FakeApi* | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional)
 *FakeApi* | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties
+*FakeApi* | [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties
 *FakeApi* | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data
 *FakeApi* | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters | 
 *FakeClassnameTags123Api* | [**TestClassname**](FakeClassnameTags123Api.md#testclassname) | **PATCH** /fake_classname_test | To test class name in snake case
@@ -218,6 +219,7 @@ Class | Method | HTTP request | Description
 - [Model.Tag](Tag.md)
 - [Model.TestCollectionEndingWithWordList](TestCollectionEndingWithWordList.md)
 - [Model.TestCollectionEndingWithWordListObject](TestCollectionEndingWithWordListObject.md)
+ - [Model.TestInlineFreeformAdditionalPropertiesRequest](TestInlineFreeformAdditionalPropertiesRequest.md)
 - [Model.Triangle](Triangle.md)
 - [Model.TriangleInterface](TriangleInterface.md)
 - [Model.User](User.md)
--- a/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/docs/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/docs/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1205,6 +1206,91 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            var apiInstance = new FakeApi(config);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/docs/TestInlineFreeformAdditionalPropertiesRequest.md
+++ b/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/docs/TestInlineFreeformAdditionalPropertiesRequest.md
@@ -0,0 +1,10 @@
+# Org.OpenAPITools.Model.TestInlineFreeformAdditionalPropertiesRequest
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**SomeProperty** | **string** |  | [optional] 
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
--- a/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/src/Org.OpenAPITools.Test/Model/TestInlineFreeformAdditionalPropertiesRequestTests.cs
@@ -0,0 +1,66 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using System;
+using System.Linq;
+using System.IO;
+using System.Collections.Generic;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Model;
+using Org.OpenAPITools.Client;
+using System.Reflection;
+using Newtonsoft.Json;
+using NUnit.Framework;
+
+namespace Org.OpenAPITools.Test.Model
+{
+    /// <summary>
+    ///  Class for testing TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    /// <remarks>
+    /// This file is automatically generated by OpenAPI Generator (https://openapi-generator.tech).
+    /// Please update the test case below to test the model.
+    /// </remarks>
+    public class TestInlineFreeformAdditionalPropertiesRequestTests : IDisposable
+    {
+        // TODO uncomment below to declare an instance variable for TestInlineFreeformAdditionalPropertiesRequest
+        //private TestInlineFreeformAdditionalPropertiesRequest instance;
+
+        public TestInlineFreeformAdditionalPropertiesRequestTests()
+        {
+            // TODO uncomment below to create an instance of TestInlineFreeformAdditionalPropertiesRequest
+            //instance = new TestInlineFreeformAdditionalPropertiesRequest();
+        }
+
+        public void Dispose()
+        {
+            // Cleanup when everything is done.
+        }
+
+        /// <summary>
+        /// Test an instance of TestInlineFreeformAdditionalPropertiesRequest
+        /// </summary>
+        [Test]
+        public void TestInlineFreeformAdditionalPropertiesRequestInstanceTest()
+        {
+            // TODO uncomment below to test "IsType" TestInlineFreeformAdditionalPropertiesRequest
+            //Assert.IsType<TestInlineFreeformAdditionalPropertiesRequest>(instance);
+        }
+
+        /// <summary>
+        /// Test the property 'SomeProperty'
+        /// </summary>
+        [Test]
+        public void SomePropertyTest()
+        {
+            // TODO unit test for the property 'SomeProperty'
+        }
+    }
+}
--- a/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/src/Org.OpenAPITools/Api/FakeApi.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/src/Org.OpenAPITools/Api/FakeApi.cs
@@ -338,6 +338,24 @@ namespace Org.OpenAPITools.Api
        /// <returns>ApiResponse of Object(void)</returns>
        ApiResponse<Object> TestInlineAdditionalPropertiesWithHttpInfo(Dictionary<string, string> requestBody);
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <returns></returns>
+        void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest);
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
@@ -753,6 +771,29 @@ namespace Org.OpenAPITools.Api
        /// <returns>Task of ApiResponse</returns>
        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineAdditionalPropertiesWithHttpInfoAsync(Dictionary<string, string> requestBody, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+
+        /// <summary>
+        /// test inline free-form additionalProperties
+        /// </summary>
+        /// <remarks>
+        /// 
+        /// </remarks>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        System.Threading.Tasks.Task<ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        /// <summary>
        /// test json serialization of form data
        /// </summary>
        /// <remarks>
@@ -2844,6 +2885,130 @@ namespace Org.OpenAPITools.Api
            return localVarResponse;
        }

+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <returns></returns>
+        public void TestInlineFreeformAdditionalProperties(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <returns>ApiResponse of Object(void)</returns>
+        public Org.OpenAPITools.Client.ApiResponse<Object> TestInlineFreeformAdditionalPropertiesWithHttpInfo(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null) localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null) localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+
+            // make the HTTP request
+            var localVarResponse = this.Client.Post<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration);
+
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null) throw _exception;
+            }
+
+            return localVarResponse;
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of void</returns>
+        public async System.Threading.Tasks.Task TestInlineFreeformAdditionalPropertiesAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            var task = TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(testInlineFreeformAdditionalPropertiesRequest, cancellationToken);
+#if UNITY_EDITOR || !UNITY_WEBGL
+            await task.ConfigureAwait(false);
+#else
+            await task;
+#endif
+        }
+
+        /// <summary>
+        /// test inline free-form additionalProperties 
+        /// </summary>
+        /// <exception cref="Org.OpenAPITools.Client.ApiException">Thrown when fails to make API call</exception>
+        /// <param name="testInlineFreeformAdditionalPropertiesRequest">request body</param>
+        /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
+        /// <returns>Task of ApiResponse</returns>
+        public async System.Threading.Tasks.Task<Org.OpenAPITools.Client.ApiResponse<Object>> TestInlineFreeformAdditionalPropertiesWithHttpInfoAsync(TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        {
+            // verify the required parameter 'testInlineFreeformAdditionalPropertiesRequest' is set
+            if (testInlineFreeformAdditionalPropertiesRequest == null)
+                throw new Org.OpenAPITools.Client.ApiException(400, "Missing required parameter 'testInlineFreeformAdditionalPropertiesRequest' when calling FakeApi->TestInlineFreeformAdditionalProperties");
+
+
+            Org.OpenAPITools.Client.RequestOptions localVarRequestOptions = new Org.OpenAPITools.Client.RequestOptions();
+
+            string[] _contentTypes = new string[] {
+                "application/json"
+            };
+
+            // to determine the Accept header
+            string[] _accepts = new string[] {
+            };
+
+
+            var localVarContentType = Org.OpenAPITools.Client.ClientUtils.SelectHeaderContentType(_contentTypes);
+            if (localVarContentType != null) localVarRequestOptions.HeaderParameters.Add("Content-Type", localVarContentType);
+
+            var localVarAccept = Org.OpenAPITools.Client.ClientUtils.SelectHeaderAccept(_accepts);
+            if (localVarAccept != null) localVarRequestOptions.HeaderParameters.Add("Accept", localVarAccept);
+
+            localVarRequestOptions.Data = testInlineFreeformAdditionalPropertiesRequest;
+
+
+            // make the HTTP request
+
+            var task = this.AsynchronousClient.PostAsync<Object>("/fake/inline-freeform-additionalProperties", localVarRequestOptions, this.Configuration, cancellationToken);
+
+#if UNITY_EDITOR || !UNITY_WEBGL
+            var localVarResponse = await task.ConfigureAwait(false);
+#else
+            var localVarResponse = await task;
+#endif
+
+            if (this.ExceptionFactory != null)
+            {
+                Exception _exception = this.ExceptionFactory("TestInlineFreeformAdditionalProperties", localVarResponse);
+                if (_exception != null) throw _exception;
+            }
+
+            return localVarResponse;
+        }
+
        /// <summary>
        /// test json serialization of form data 
        /// </summary>
--- a/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient-unityWebRequest/src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
@@ -0,0 +1,132 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * Generated by: https://github.com/openapitools/openapi-generator.git
+ */
+
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.IO;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Text.RegularExpressions;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+using Newtonsoft.Json.Linq;
+using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
+
+namespace Org.OpenAPITools.Model
+{
+    /// <summary>
+    /// TestInlineFreeformAdditionalPropertiesRequest
+    /// </summary>
+    [DataContract(Name = "testInlineFreeformAdditionalProperties_request")]
+    public partial class TestInlineFreeformAdditionalPropertiesRequest : Dictionary<String, Object>, IEquatable<TestInlineFreeformAdditionalPropertiesRequest>
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TestInlineFreeformAdditionalPropertiesRequest" /> class.
+        /// </summary>
+        /// <param name="someProperty">someProperty.</param>
+        public TestInlineFreeformAdditionalPropertiesRequest(string someProperty = default(string)) : base()
+        {
+            this.SomeProperty = someProperty;
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
+
+        /// <summary>
+        /// Gets or Sets SomeProperty
+        /// </summary>
+        [DataMember(Name = "someProperty", EmitDefaultValue = false)]
+        public string SomeProperty { get; set; }
+
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append("class TestInlineFreeformAdditionalPropertiesRequest {\n");
+            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
+            sb.Append("  SomeProperty: ").Append(SomeProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return Newtonsoft.Json.JsonConvert.SerializeObject(this, Newtonsoft.Json.Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="input">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object input)
+        {
+            return this.Equals(input as TestInlineFreeformAdditionalPropertiesRequest);
+        }
+
+        /// <summary>
+        /// Returns true if TestInlineFreeformAdditionalPropertiesRequest instances are equal
+        /// </summary>
+        /// <param name="input">Instance of TestInlineFreeformAdditionalPropertiesRequest to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestInlineFreeformAdditionalPropertiesRequest input)
+        {
+            if (input == null)
+            {
+                return false;
+            }
+            return base.Equals(input) && 
+                (
+                    this.SomeProperty == input.SomeProperty ||
+                    (this.SomeProperty != null &&
+                    this.SomeProperty.Equals(input.SomeProperty))
+                )
+                && (this.AdditionalProperties.Count == input.AdditionalProperties.Count && !this.AdditionalProperties.Except(input.AdditionalProperties).Any());
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                int hashCode = base.GetHashCode();
+                if (this.SomeProperty != null)
+                {
+                    hashCode = (hashCode * 59) + this.SomeProperty.GetHashCode();
+                }
+                if (this.AdditionalProperties != null)
+                {
+                    hashCode = (hashCode * 59) + this.AdditionalProperties.GetHashCode();
+                }
+                return hashCode;
+            }
+        }
+
+    }
+
+}
--- a/samples/client/petstore/csharp/OpenAPIClient/.openapi-generator/FILES
+++ b/samples/client/petstore/csharp/OpenAPIClient/.openapi-generator/FILES
@@ -90,6 +90,7 @@ docs/StoreApi.md
 docs/Tag.md
 docs/TestCollectionEndingWithWordList.md
 docs/TestCollectionEndingWithWordListObject.md
+docs/TestInlineFreeformAdditionalPropertiesRequest.md
 docs/Triangle.md
 docs/TriangleInterface.md
 docs/User.md
@@ -208,6 +209,7 @@ src/Org.OpenAPITools/Model/SpecialModelName.cs
 src/Org.OpenAPITools/Model/Tag.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs
 src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs
+src/Org.OpenAPITools/Model/TestInlineFreeformAdditionalPropertiesRequest.cs
 src/Org.OpenAPITools/Model/Triangle.cs
 src/Org.OpenAPITools/Model/TriangleInterface.cs
 src/Org.OpenAPITools/Model/User.cs
--- a/samples/client/petstore/csharp/OpenAPIClient/README.md
+++ b/samples/client/petstore/csharp/OpenAPIClient/README.md
@@ -122,6 +122,7 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**TestEnumParameters**](docs/FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters
 *FakeApi* | [**TestGroupParameters**](docs/FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional)
 *FakeApi* | [**TestInlineAdditionalProperties**](docs/FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties
+*FakeApi* | [**TestInlineFreeformAdditionalProperties**](docs/FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties
 *FakeApi* | [**TestJsonFormData**](docs/FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data
 *FakeApi* | [**TestQueryParameterCollectionFormat**](docs/FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters | 
 *FakeClassnameTags123Api* | [**TestClassname**](docs/FakeClassnameTags123Api.md#testclassname) | **PATCH** /fake_classname_test | To test class name in snake case
@@ -232,6 +233,7 @@ Class | Method | HTTP request | Description
 - [Model.Tag](docs/Tag.md)
 - [Model.TestCollectionEndingWithWordList](docs/TestCollectionEndingWithWordList.md)
 - [Model.TestCollectionEndingWithWordListObject](docs/TestCollectionEndingWithWordListObject.md)
+ - [Model.TestInlineFreeformAdditionalPropertiesRequest](docs/TestInlineFreeformAdditionalPropertiesRequest.md)
 - [Model.Triangle](docs/Triangle.md)
 - [Model.TriangleInterface](docs/TriangleInterface.md)
 - [Model.User](docs/User.md)
--- a/samples/client/petstore/csharp/OpenAPIClient/api/openapi.yaml
+++ b/samples/client/petstore/csharp/OpenAPIClient/api/openapi.yaml
@@ -943,6 +943,23 @@ paths:
      summary: test inline additionalProperties
      tags:
      - fake
+  /fake/inline-freeform-additionalProperties:
+    post:
+      description: ""
+      operationId: testInlineFreeformAdditionalProperties
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/testInlineFreeformAdditionalProperties_request'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test inline free-form additionalProperties
+      tags:
+      - fake
  /fake/body-with-query-params:
    put:
      operationId: testBodyWithQueryParams
@@ -2488,6 +2505,12 @@ components:
      - param
      - param2
      type: object
+    testInlineFreeformAdditionalProperties_request:
+      additionalProperties: true
+      properties:
+        someProperty:
+          type: string
+      type: object
    uploadFileWithRequiredFile_request:
      properties:
        additionalMetadata:
--- a/samples/client/petstore/csharp/OpenAPIClient/docs/FakeApi.md
+++ b/samples/client/petstore/csharp/OpenAPIClient/docs/FakeApi.md
@@ -17,6 +17,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**TestEnumParameters**](FakeApi.md#testenumparameters) | **GET** /fake | To test enum parameters |
 | [**TestGroupParameters**](FakeApi.md#testgroupparameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional) |
 | [**TestInlineAdditionalProperties**](FakeApi.md#testinlineadditionalproperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties |
+| [**TestInlineFreeformAdditionalProperties**](FakeApi.md#testinlinefreeformadditionalproperties) | **POST** /fake/inline-freeform-additionalProperties | test inline free-form additionalProperties |
 | [**TestJsonFormData**](FakeApi.md#testjsonformdata) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**TestQueryParameterCollectionFormat**](FakeApi.md#testqueryparametercollectionformat) | **PUT** /fake/test-query-parameters |  |

@@ -1205,6 +1206,91 @@ No authorization required
 - **Accept**: Not defined


+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+
+<a id="testinlinefreeformadditionalproperties"></a>
+# **TestInlineFreeformAdditionalProperties**
+> void TestInlineFreeformAdditionalProperties (TestInlineFreeformAdditionalPropertiesRequest testInlineFreeformAdditionalPropertiesRequest)
+
+test inline free-form additionalProperties
+
+### Example
+```csharp
+using System.Collections.Generic;
+using System.Diagnostics;
+using Org.OpenAPITools.Api;
+using Org.OpenAPITools.Client;
+using Org.OpenAPITools.Model;
+
+namespace Example
+{
+    public class TestInlineFreeformAdditionalPropertiesExample
+    {
+        public static void Main()
+        {
+            Configuration config = new Configuration();
+            config.BasePath = "http://petstore.swagger.io:80/v2";
+            var apiInstance = new FakeApi(config);
+            var testInlineFreeformAdditionalPropertiesRequest = new TestInlineFreeformAdditionalPropertiesRequest(); // TestInlineFreeformAdditionalPropertiesRequest | request body
+
+            try
+            {
+                // test inline free-form additionalProperties
+                apiInstance.TestInlineFreeformAdditionalProperties(testInlineFreeformAdditionalPropertiesRequest);
+            }
+            catch (ApiException  e)
+            {
+                Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalProperties: " + e.Message);
+                Debug.Print("Status Code: " + e.ErrorCode);
+                Debug.Print(e.StackTrace);
+            }
+        }
+    }
+}
+```
+
+#### Using the TestInlineFreeformAdditionalPropertiesWithHttpInfo variant
+This returns an ApiResponse object which contains the response data, status code and headers.
+
+```csharp
+try
+{
+    // test inline free-form additionalProperties
+    apiInstance.TestInlineFreeformAdditionalPropertiesWithHttpInfo(testInlineFreeformAdditionalPropertiesRequest);
+}
+catch (ApiException e)
+{
+    Debug.Print("Exception when calling FakeApi.TestInlineFreeformAdditionalPropertiesWithHttpInfo: " + e.Message);
+    Debug.Print("Status Code: " + e.ErrorCode);
+    Debug.Print(e.StackTrace);
+}
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+|------|------|-------------|-------|
+| **testInlineFreeformAdditionalPropertiesRequest** | [**TestInlineFreeformAdditionalPropertiesRequest**](TestInlineFreeformAdditionalPropertiesRequest.md) | request body |  |
+
+### Return type
+
+void (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+
 ### HTTP response details
 | Status code | Description | Response headers |
 |-------------|-------------|------------------|
--- a/Show More
+++ b/Show More