diff --git a/modules/openapi-generator/src/main/resources/C-libcurl/model-body.mustache b/modules/openapi-generator/src/main/resources/C-libcurl/model-body.mustache
index 3a513e9c2cd5..1f28e05e9099 100644
--- a/modules/openapi-generator/src/main/resources/C-libcurl/model-body.mustache
+++ b/modules/openapi-generator/src/main/resources/C-libcurl/model-body.mustache
@@ -136,6 +136,11 @@ char* {{name}}{{classname}}_ToString({{projectName}}_{{classVarName}}_{{enumName
     {{datatype}}_t *{{name}}{{^-last}},{{/-last}}
     {{/isEnum}}
     {{/isModel}}
+    {{^isModel}}
+    {{^isFreeFormObject}}
+    {{datatype}}_t *{{name}}{{^-last}},{{/-last}}
+    {{/isFreeFormObject}}
+    {{/isModel}}
     {{#isUuid}}
     {{datatype}} *{{name}}{{^-last}},{{/-last}}
     {{/isUuid}}
@@ -220,6 +225,14 @@ void {{classname}}_free({{classname}}_t *{{classname}}) {
     }
     {{/isEnum}}
     {{/isModel}}
+    {{^isModel}}
+    {{^isFreeFormObject}}
+    if ({{{classname}}}->{{{name}}}) {
+        {{{complexType}}}_free({{{classname}}}->{{{name}}});
+        {{classname}}->{{name}} = NULL;
+    }
+    {{/isFreeFormObject}}
+    {{/isModel}}
     {{#isUuid}}
     if ({{{classname}}}->{{{name}}}) {
         free({{{classname}}}->{{{name}}});
@@ -398,6 +411,18 @@ cJSON *{{classname}}_convertToJSON({{classname}}_t *{{classname}}) {
     }
     {{/isEnum}}
     {{/isModel}}
+    {{^isModel}}
+    {{^isFreeFormObject}}
+    cJSON *{{{name}}}_local_JSON = {{complexType}}_convertToJSON({{{classname}}}->{{{name}}});
+    if({{{name}}}_local_JSON == NULL) {
+        goto fail; // custom
+    }
+    cJSON_AddItemToObject(item, "{{{baseName}}}", {{{name}}}_local_JSON);
+    if(item->child == NULL) {
+        goto fail;
+    }
+    {{/isFreeFormObject}}
+    {{/isModel}}
     {{#isUuid}}
     if(cJSON_AddStringToObject(item, "{{{baseName}}}", {{{classname}}}->{{{name}}}) == NULL) {
     goto fail; //uuid
@@ -528,6 +553,7 @@ fail:
     {{classname}}_t *{{classname}}_local_var = NULL;
 
     {{#vars}}
+    {{^isContainer}}
     {{^isPrimitiveType}}
     {{#isModel}}
     {{^isEnum}}
@@ -536,7 +562,15 @@ fail:
 
     {{/isEnum}}
     {{/isModel}}
+    {{^isModel}}
+    {{^isFreeFormObject}}
+    // define the local variable for {{{classname}}}->{{{name}}}
+    {{complexType}}_t *{{name}}_local_nonprim = NULL;
+
+    {{/isFreeFormObject}}
+    {{/isModel}}
     {{/isPrimitiveType}}
+    {{/isContainer}}
     {{/vars}}
     {{#vars}}
     // {{{classname}}}->{{{name}}}
@@ -629,6 +663,12 @@ fail:
     {{{name}}}_local_nonprim = {{complexType}}{{#isFreeFormObject}}object{{/isFreeFormObject}}_parseFromJSON({{{name}}}); //nonprimitive
     {{/isEnum}}
     {{/isModel}}
+    {{^isModel}}
+    {{^isFreeFormObject}}
+    {{^required}}if ({{{name}}}) { {{/required}}
+    {{{name}}}_local_nonprim = {{complexType}}_parseFromJSON({{{name}}}); //custom
+    {{/isFreeFormObject}}
+    {{/isModel}}
     {{#isUuid}}
     {{^required}}if ({{{name}}}) { {{/required}}
     if(!cJSON_IsString({{{name}}}))
@@ -779,6 +819,11 @@ fail:
         {{^required}}{{{name}}} ? {{/required}}{{{name}}}_local_nonprim{{^required}} : NULL{{/required}}{{^-last}},{{/-last}}
         {{/isEnum}}
         {{/isModel}}
+        {{^isModel}}
+        {{^isFreeFormObject}}
+        {{^required}}{{{name}}} ? {{/required}}{{{name}}}_local_nonprim{{^required}} : NULL{{/required}}{{^-last}},{{/-last}}
+        {{/isFreeFormObject}}
+        {{/isModel}}
         {{#isUuid}}
         {{^required}}{{{name}}} ? {{/required}}strdup({{{name}}}->valuestring){{^required}} : NULL{{/required}}{{^-last}},{{/-last}}
         {{/isUuid}}
@@ -849,6 +894,14 @@ end:
     }
     {{/isEnum}}
     {{/isModel}}
+    {{^isModel}}
+    {{^isFreeFormObject}}
+    if ({{{name}}}_local_nonprim) {
+        {{complexType}}_free({{{name}}}_local_nonprim);
+        {{{name}}}_local_nonprim = NULL;
+    }
+    {{/isFreeFormObject}}
+    {{/isModel}}
     {{/isPrimitiveType}}
     {{/isContainer}}
     {{/vars}}
diff --git a/modules/openapi-generator/src/main/resources/C-libcurl/model-header.mustache b/modules/openapi-generator/src/main/resources/C-libcurl/model-header.mustache
index 5bdff9f1dbfe..81aee8c17a38 100644
--- a/modules/openapi-generator/src/main/resources/C-libcurl/model-header.mustache
+++ b/modules/openapi-generator/src/main/resources/C-libcurl/model-header.mustache
@@ -86,6 +86,11 @@ typedef struct {{classname}}_t {
     struct {{datatype}}_t *{{name}}; //model
     {{/isEnum}}
     {{/isModel}}
+    {{^isModel}}
+    {{^isFreeFormObject}}
+    {{datatype}}_t *{{name}}; // custom
+    {{/isFreeFormObject}}
+    {{/isModel}}
     {{#isUuid}}
     {{datatype}} *{{name}}; // uuid
     {{/isUuid}}
@@ -156,6 +161,11 @@ typedef struct {{classname}}_t {
     {{datatype}}_t *{{name}}{{^-last}},{{/-last}}
     {{/isEnum}}
     {{/isModel}}
+    {{^isModel}}
+    {{^isFreeFormObject}}
+    {{datatype}}_t *{{name}}{{^-last}},{{/-last}}
+    {{/isFreeFormObject}}
+    {{/isModel}}
     {{#isUuid}}
     {{datatype}} *{{name}}{{^-last}},{{/-last}}
     {{/isUuid}}
diff --git a/modules/openapi-generator/src/main/resources/C-libcurl/model_doc.mustache b/modules/openapi-generator/src/main/resources/C-libcurl/model_doc.mustache
index 77f14ca235c9..823834d7ae3f 100644
--- a/modules/openapi-generator/src/main/resources/C-libcurl/model_doc.mustache
+++ b/modules/openapi-generator/src/main/resources/C-libcurl/model_doc.mustache
@@ -4,7 +4,7 @@
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
 {{#vars}}
-**{{name}}** | {{^isContainer}}{{^isPrimitiveType}}{{#isModel}}{{#isEnum}}**{{projectName}}_{{classVarName}}_{{enumName}}_e**{{/isEnum}}{{^isEnum}}[**{{datatype}}_t**]({{complexType}}.md) \*{{/isEnum}}{{/isModel}}{{#isUuid}}**{{datatype}} \***{{/isUuid}}{{#isEmail}}**{{datatype}} \***{{/isEmail}}{{#isFreeFormObject}}[**{{datatype}}_t**]({{complexType}}.md) \*{{/isFreeFormObject}}{{/isPrimitiveType}}{{#isPrimitiveType}}{{#isNumeric}}**{{datatype}}**{{/isNumeric}}{{#isBoolean}}**{{datatype}}**{{/isBoolean}}{{#isEnum}}{{#isString}}**{{projectName}}_{{classVarName}}_{{enumName}}_e**{{/isString}}{{/isEnum}}{{^isEnum}}{{#isString}}**{{datatype}} \***{{/isString}}{{/isEnum}}{{#isByteArray}}**{{datatype}} \***{{/isByteArray}}{{#isBinary}}**{{datatype}}**{{/isBinary}}{{#isDate}}**{{datatype}} \***{{/isDate}}{{#isDateTime}}**{{datatype}} \***{{/isDateTime}}{{/isPrimitiveType}}{{/isContainer}}{{#isContainer}}{{#isArray}}{{#isPrimitiveType}}**{{datatype}}_t \***{{/isPrimitiveType}}{{^isPrimitiveType}}[**{{datatype}}_t**]({{complexType}}.md) \*{{/isPrimitiveType}}{{/isArray}}{{#isMap}}**{{datatype}}**{{/isMap}}{{/isContainer}} | {{description}} | {{^required}}[optional] {{/required}}{{#isReadOnly}}[readonly] {{/isReadOnly}}{{#defaultValue}}[default to {{{.}}}]{{/defaultValue}}
+**{{name}}** | {{^isContainer}}{{^isPrimitiveType}}{{#isModel}}{{#isEnum}}**{{projectName}}_{{classVarName}}_{{enumName}}_e**{{/isEnum}}{{^isEnum}}[**{{datatype}}_t**]({{complexType}}.md) \*{{/isEnum}}{{/isModel}}{{^isModel}}{{^isFreeFormObject}}**{{datatype}}_t \***{{/isFreeFormObject}}{{/isModel}}{{#isUuid}}**{{datatype}} \***{{/isUuid}}{{#isEmail}}**{{datatype}} \***{{/isEmail}}{{#isFreeFormObject}}[**{{datatype}}_t**]({{complexType}}.md) \*{{/isFreeFormObject}}{{/isPrimitiveType}}{{#isPrimitiveType}}{{#isNumeric}}**{{datatype}}**{{/isNumeric}}{{#isBoolean}}**{{datatype}}**{{/isBoolean}}{{#isEnum}}{{#isString}}**{{projectName}}_{{classVarName}}_{{enumName}}_e**{{/isString}}{{/isEnum}}{{^isEnum}}{{#isString}}**{{datatype}} \***{{/isString}}{{/isEnum}}{{#isByteArray}}**{{datatype}} \***{{/isByteArray}}{{#isBinary}}**{{datatype}}**{{/isBinary}}{{#isDate}}**{{datatype}} \***{{/isDate}}{{#isDateTime}}**{{datatype}} \***{{/isDateTime}}{{/isPrimitiveType}}{{/isContainer}}{{#isContainer}}{{#isArray}}{{#isPrimitiveType}}**{{datatype}}_t \***{{/isPrimitiveType}}{{^isPrimitiveType}}[**{{datatype}}_t**]({{complexType}}.md) \*{{/isPrimitiveType}}{{/isArray}}{{#isMap}}**{{datatype}}**{{/isMap}}{{/isContainer}} | {{description}} | {{^required}}[optional] {{/required}}{{#isReadOnly}}[readonly] {{/isReadOnly}}{{#defaultValue}}[default to {{{.}}}]{{/defaultValue}}
 {{/vars}}
 
 [[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)