diff --git a/modules/openapi-generator/src/main/resources/php/api.mustache b/modules/openapi-generator/src/main/resources/php/api.mustache
index a80d08486bda..421984d0209c 100644
--- a/modules/openapi-generator/src/main/resources/php/api.mustache
+++ b/modules/openapi-generator/src/main/resources/php/api.mustache
@@ -406,7 +406,7 @@ use {{invokerPackage}}\ObjectSerializer;
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function {{operationId}}Request({{^vendorExtensions.x-group-parameters}}{{#allParams}}${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}}{{#hasMore}}, {{/hasMore}}{{/allParams}}{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}$associative_array{{/vendorExtensions.x-group-parameters}})
+    public function {{operationId}}Request({{^vendorExtensions.x-group-parameters}}{{#allParams}}${{paramName}}{{^required}} = {{#defaultValue}}{{{.}}}{{/defaultValue}}{{^defaultValue}}null{{/defaultValue}}{{/required}}{{#hasMore}}, {{/hasMore}}{{/allParams}}{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}$associative_array{{/vendorExtensions.x-group-parameters}})
     {
         {{#vendorExtensions.x-group-parameters}}
         // unbox the parameters from the associative array
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/AnotherFakeApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/AnotherFakeApi.php
index b328c2627c4e..bb0ed8fb0b4a 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/AnotherFakeApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/AnotherFakeApi.php
@@ -297,7 +297,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function call123TestSpecialTagsRequest($client)
+    public function call123TestSpecialTagsRequest($client)
     {
         // verify the required parameter 'client' is set
         if ($client === null || (is_array($client) && count($client) === 0)) {
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/DefaultApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/DefaultApi.php
index 00c5f27ccee4..ca4f3e85ddd3 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/DefaultApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/DefaultApi.php
@@ -288,7 +288,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function fooGetRequest()
+    public function fooGetRequest()
     {
 
         $resourcePath = '/foo';
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
index 0b99c8e9aab3..be0f5ea51550 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeApi.php
@@ -292,7 +292,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function fakeHealthGetRequest()
+    public function fakeHealthGetRequest()
     {
 
         $resourcePath = '/fake/health';
@@ -516,7 +516,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function fakeHttpSignatureTestRequest($pet, $query_1 = null, $header_1 = null)
+    public function fakeHttpSignatureTestRequest($pet, $query_1 = null, $header_1 = null)
     {
         // verify the required parameter 'pet' is set
         if ($pet === null || (is_array($pet) && count($pet) === 0)) {
@@ -798,7 +798,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function fakeOuterBooleanSerializeRequest($body = null)
+    public function fakeOuterBooleanSerializeRequest($body = null)
     {
 
         $resourcePath = '/fake/outer/boolean';
@@ -1059,7 +1059,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function fakeOuterCompositeSerializeRequest($outer_composite = null)
+    public function fakeOuterCompositeSerializeRequest($outer_composite = null)
     {
 
         $resourcePath = '/fake/outer/composite';
@@ -1320,7 +1320,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function fakeOuterNumberSerializeRequest($body = null)
+    public function fakeOuterNumberSerializeRequest($body = null)
     {
 
         $resourcePath = '/fake/outer/number';
@@ -1581,7 +1581,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function fakeOuterStringSerializeRequest($body = null)
+    public function fakeOuterStringSerializeRequest($body = null)
     {
 
         $resourcePath = '/fake/outer/string';
@@ -1794,7 +1794,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function testBodyWithFileSchemaRequest($file_schema_test_class)
+    public function testBodyWithFileSchemaRequest($file_schema_test_class)
     {
         // verify the required parameter 'file_schema_test_class' is set
         if ($file_schema_test_class === null || (is_array($file_schema_test_class) && count($file_schema_test_class) === 0)) {
@@ -2018,7 +2018,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function testBodyWithQueryParamsRequest($query, $user)
+    public function testBodyWithQueryParamsRequest($query, $user)
     {
         // verify the required parameter 'query' is set
         if ($query === null || (is_array($query) && count($query) === 0)) {
@@ -2306,7 +2306,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function testClientModelRequest($client)
+    public function testClientModelRequest($client)
     {
         // verify the required parameter 'client' is set
         if ($client === null || (is_array($client) && count($client) === 0)) {
@@ -2594,7 +2594,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function testEndpointParametersRequest($number, $double, $pattern_without_delimiter, $byte, $integer = null, $int32 = null, $int64 = null, $float = null, $string = null, $binary = null, $date = null, $date_time = null, $password = null, $callback = null)
+    public function testEndpointParametersRequest($number, $double, $pattern_without_delimiter, $byte, $integer = null, $int32 = null, $int64 = null, $float = null, $string = null, $binary = null, $date = null, $date_time = null, $password = null, $callback = null)
     {
         // verify the required parameter 'number' is set
         if ($number === null || (is_array($number) && count($number) === 0)) {
@@ -2982,7 +2982,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function testEnumParametersRequest($enum_header_string_array = null, $enum_header_string = '-efg', $enum_query_string_array = null, $enum_query_string = '-efg', $enum_query_integer = null, $enum_query_double = null, $enum_form_string_array = '$', $enum_form_string = '-efg')
+    public function testEnumParametersRequest($enum_header_string_array = null, $enum_header_string = '-efg', $enum_query_string_array = null, $enum_query_string = '-efg', $enum_query_integer = null, $enum_query_double = null, $enum_form_string_array = '$', $enum_form_string = '-efg')
     {
 
         $resourcePath = '/fake';
@@ -3294,7 +3294,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function testGroupParametersRequest($associative_array)
+    public function testGroupParametersRequest($associative_array)
     {
         // unbox the parameters from the associative array
         $required_string_group = array_key_exists('required_string_group', $associative_array) ? $associative_array['required_string_group'] : null;
@@ -3590,7 +3590,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function testInlineAdditionalPropertiesRequest($request_body)
+    public function testInlineAdditionalPropertiesRequest($request_body)
     {
         // verify the required parameter 'request_body' is set
         if ($request_body === null || (is_array($request_body) && count($request_body) === 0)) {
@@ -3818,7 +3818,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function testJsonFormDataRequest($param, $param2)
+    public function testJsonFormDataRequest($param, $param2)
     {
         // verify the required parameter 'param' is set
         if ($param === null || (is_array($param) && count($param) === 0)) {
@@ -4068,7 +4068,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $http, $url, $context)
+    public function testQueryParameterCollectionFormatRequest($pipe, $ioutil, $http, $url, $context)
     {
         // verify the required parameter 'pipe' is set
         if ($pipe === null || (is_array($pipe) && count($pipe) === 0)) {
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeClassnameTags123Api.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeClassnameTags123Api.php
index 094e5e914983..210a42b82e2f 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeClassnameTags123Api.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/FakeClassnameTags123Api.php
@@ -297,7 +297,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function testClassnameRequest($client)
+    public function testClassnameRequest($client)
     {
         // verify the required parameter 'client' is set
         if ($client === null || (is_array($client) && count($client) === 0)) {
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
index e92065f162b2..5e6afd88b56b 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/PetApi.php
@@ -269,7 +269,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function addPetRequest($pet)
+    public function addPetRequest($pet)
     {
         // verify the required parameter 'pet' is set
         if ($pet === null || (is_array($pet) && count($pet) === 0)) {
@@ -507,7 +507,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function deletePetRequest($pet_id, $api_key = null)
+    public function deletePetRequest($pet_id, $api_key = null)
     {
         // verify the required parameter 'pet_id' is set
         if ($pet_id === null || (is_array($pet_id) && count($pet_id) === 0)) {
@@ -791,7 +791,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function findPetsByStatusRequest($status)
+    public function findPetsByStatusRequest($status)
     {
         // verify the required parameter 'status' is set
         if ($status === null || (is_array($status) && count($status) === 0)) {
@@ -1070,7 +1070,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function findPetsByTagsRequest($tags)
+    public function findPetsByTagsRequest($tags)
     {
         // verify the required parameter 'tags' is set
         if ($tags === null || (is_array($tags) && count($tags) === 0)) {
@@ -1349,7 +1349,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function getPetByIdRequest($pet_id)
+    public function getPetByIdRequest($pet_id)
     {
         // verify the required parameter 'pet_id' is set
         if ($pet_id === null || (is_array($pet_id) && count($pet_id) === 0)) {
@@ -1602,7 +1602,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function updatePetRequest($pet)
+    public function updatePetRequest($pet)
     {
         // verify the required parameter 'pet' is set
         if ($pet === null || (is_array($pet) && count($pet) === 0)) {
@@ -1845,7 +1845,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function updatePetWithFormRequest($pet_id, $name = null, $status = null)
+    public function updatePetWithFormRequest($pet_id, $name = null, $status = null)
     {
         // verify the required parameter 'pet_id' is set
         if ($pet_id === null || (is_array($pet_id) && count($pet_id) === 0)) {
@@ -2143,7 +2143,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function uploadFileRequest($pet_id, $additional_metadata = null, $file = null)
+    public function uploadFileRequest($pet_id, $additional_metadata = null, $file = null)
     {
         // verify the required parameter 'pet_id' is set
         if ($pet_id === null || (is_array($pet_id) && count($pet_id) === 0)) {
@@ -2449,7 +2449,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function uploadFileWithRequiredFileRequest($pet_id, $required_file, $additional_metadata = null)
+    public function uploadFileWithRequiredFileRequest($pet_id, $required_file, $additional_metadata = null)
     {
         // verify the required parameter 'pet_id' is set
         if ($pet_id === null || (is_array($pet_id) && count($pet_id) === 0)) {
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/StoreApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/StoreApi.php
index d4e853de9c3c..1f9913c62c8c 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/StoreApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/StoreApi.php
@@ -249,7 +249,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function deleteOrderRequest($order_id)
+    public function deleteOrderRequest($order_id)
     {
         // verify the required parameter 'order_id' is set
         if ($order_id === null || (is_array($order_id) && count($order_id) === 0)) {
@@ -520,7 +520,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function getInventoryRequest()
+    public function getInventoryRequest()
     {
 
         $resourcePath = '/store/inventory';
@@ -787,7 +787,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function getOrderByIdRequest($order_id)
+    public function getOrderByIdRequest($order_id)
     {
         // verify the required parameter 'order_id' is set
         if ($order_id === null || (is_array($order_id) && count($order_id) === 0)) {
@@ -1070,7 +1070,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function placeOrderRequest($order)
+    public function placeOrderRequest($order)
     {
         // verify the required parameter 'order' is set
         if ($order === null || (is_array($order) && count($order) === 0)) {
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
index 5e26aa165b3b..dd9f9dc21be2 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/Api/UserApi.php
@@ -249,7 +249,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function createUserRequest($user)
+    public function createUserRequest($user)
     {
         // verify the required parameter 'user' is set
         if ($user === null || (is_array($user) && count($user) === 0)) {
@@ -472,7 +472,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function createUsersWithArrayInputRequest($user)
+    public function createUsersWithArrayInputRequest($user)
     {
         // verify the required parameter 'user' is set
         if ($user === null || (is_array($user) && count($user) === 0)) {
@@ -695,7 +695,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function createUsersWithListInputRequest($user)
+    public function createUsersWithListInputRequest($user)
     {
         // verify the required parameter 'user' is set
         if ($user === null || (is_array($user) && count($user) === 0)) {
@@ -918,7 +918,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function deleteUserRequest($username)
+    public function deleteUserRequest($username)
     {
         // verify the required parameter 'username' is set
         if ($username === null || (is_array($username) && count($username) === 0)) {
@@ -1194,7 +1194,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function getUserByNameRequest($username)
+    public function getUserByNameRequest($username)
     {
         // verify the required parameter 'username' is set
         if ($username === null || (is_array($username) && count($username) === 0)) {
@@ -1475,7 +1475,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function loginUserRequest($username, $password)
+    public function loginUserRequest($username, $password)
     {
         // verify the required parameter 'username' is set
         if ($username === null || (is_array($username) && count($username) === 0)) {
@@ -1718,7 +1718,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function logoutUserRequest()
+    public function logoutUserRequest()
     {
 
         $resourcePath = '/user/logout';
@@ -1937,7 +1937,7 @@ function ($exception) {
      * @throws \InvalidArgumentException
      * @return \GuzzleHttp\Psr7\Request
      */
-    protected function updateUserRequest($username, $user)
+    public function updateUserRequest($username, $user)
     {
         // verify the required parameter 'username' is set
         if ($username === null || (is_array($username) && count($username) === 0)) {