diff --git a/clients/algoliasearch-client-javascript/packages/client-common/src/transporter/createTransporter.ts b/clients/algoliasearch-client-javascript/packages/client-common/src/transporter/createTransporter.ts
index fa9a44c48f..ce4a832332 100644
--- a/clients/algoliasearch-client-javascript/packages/client-common/src/transporter/createTransporter.ts
+++ b/clients/algoliasearch-client-javascript/packages/client-common/src/transporter/createTransporter.ts
@@ -240,13 +240,13 @@ export function createTransporter({
       cacheable: baseRequestOptions?.cacheable,
       timeout: baseRequestOptions?.timeout,
       queryParameters: {
-        ...methodOptions.queryParameters,
         ...baseRequestOptions?.queryParameters,
+        ...methodOptions.queryParameters,
       },
       headers: {
         Accept: 'application/json',
-        ...methodOptions.headers,
         ...baseRequestOptions?.headers,
+        ...methodOptions.headers,
       },
     };
 
diff --git a/clients/algoliasearch-client-php/lib/Api/AbtestingClient.php b/clients/algoliasearch-client-php/lib/Api/AbtestingClient.php
index 409ba1f295..66838990d0 100644
--- a/clients/algoliasearch-client-php/lib/Api/AbtestingClient.php
+++ b/clients/algoliasearch-client-php/lib/Api/AbtestingClient.php
@@ -109,7 +109,7 @@ public function getClientConfig()
      *
      * @see \Algolia\AlgoliaSearch\Model\Abtesting\AddABTestsRequest
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Abtesting\ABTestResponse
      */
@@ -127,16 +127,17 @@ public function addABTests($addABTestsRequest, $requestOptions = [])
 
         $resourcePath = '/2/abtests';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($addABTestsRequest)) {
             $httpBody = $addABTestsRequest;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -148,7 +149,7 @@ public function addABTests($addABTestsRequest, $requestOptions = [])
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -163,6 +164,7 @@ public function del($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -187,11 +189,10 @@ public function del($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -202,7 +203,7 @@ public function del($path, $parameters = null, $requestOptions = [])
      * Delete a test.
      *
      * @param int $id The A/B test ID. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Abtesting\ABTestResponse
      */
@@ -217,6 +218,7 @@ public function deleteABTest($id, $requestOptions = [])
 
         $resourcePath = '/2/abtests/{id}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -228,11 +230,10 @@ public function deleteABTest($id, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -244,7 +245,7 @@ public function deleteABTest($id, $requestOptions = [])
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -259,6 +260,7 @@ public function get($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -283,11 +285,10 @@ public function get($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -298,7 +299,7 @@ public function get($path, $parameters = null, $requestOptions = [])
      * Get a test.
      *
      * @param int $id The A/B test ID. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Abtesting\ABTest
      */
@@ -313,6 +314,7 @@ public function getABTest($id, $requestOptions = [])
 
         $resourcePath = '/2/abtests/{id}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -324,11 +326,10 @@ public function getABTest($id, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -340,7 +341,7 @@ public function getABTest($id, $requestOptions = [])
      *
      * @param int $offset Position of the starting record. Used for paging. 0 is the first record. (optional, default to 0)
      * @param int $limit Number of records to return. Limit is the size of the page. (optional, default to 10)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Abtesting\ListABTestsResponse
      */
@@ -351,6 +352,7 @@ public function listABTests(
     ) {
         $resourcePath = '/2/abtests';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($offset !== null) {
@@ -387,11 +389,10 @@ public function listABTests(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -404,7 +405,7 @@ public function listABTests(
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -423,6 +424,7 @@ public function post(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -450,11 +452,11 @@ public function post(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -467,7 +469,7 @@ public function post(
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -486,6 +488,7 @@ public function put(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -513,11 +516,11 @@ public function put(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -528,7 +531,7 @@ public function put(
      * Stop a test.
      *
      * @param int $id The A/B test ID. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Abtesting\ABTestResponse
      */
@@ -543,6 +546,7 @@ public function stopABTest($id, $requestOptions = [])
 
         $resourcePath = '/2/abtests/{id}/stop';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -554,11 +558,10 @@ public function stopABTest($id, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -568,11 +571,30 @@ public function stopABTest($id, $requestOptions = [])
     private function sendRequest(
         $method,
         $resourcePath,
+        $headers,
         $queryParameters,
         $httpBody,
         $requestOptions
     ) {
-        $query = \GuzzleHttp\Psr7\Query::build($queryParameters);
+        if (!isset($requestOptions['headers'])) {
+            $requestOptions['headers'] = [];
+        }
+        if (!isset($requestOptions['queryParameters'])) {
+            $requestOptions['queryParameters'] = [];
+        }
+
+        $requestOptions['headers'] = array_merge(
+            $headers,
+            $requestOptions['headers']
+        );
+        $requestOptions['queryParameters'] = array_merge(
+            $queryParameters,
+            $requestOptions['queryParameters']
+        );
+
+        $query = \GuzzleHttp\Psr7\Query::build(
+            $requestOptions['queryParameters']
+        );
 
         if ($method === 'GET') {
             $request = $this->api->read(
diff --git a/clients/algoliasearch-client-php/lib/Api/AnalyticsClient.php b/clients/algoliasearch-client-php/lib/Api/AnalyticsClient.php
index bdb43b7a44..11995dfc4e 100644
--- a/clients/algoliasearch-client-php/lib/Api/AnalyticsClient.php
+++ b/clients/algoliasearch-client-php/lib/Api/AnalyticsClient.php
@@ -104,7 +104,7 @@ public function getClientConfig()
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -119,6 +119,7 @@ public function del($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -143,11 +144,10 @@ public function del($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -159,7 +159,7 @@ public function del($path, $parameters = null, $requestOptions = [])
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -174,6 +174,7 @@ public function get($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -198,11 +199,10 @@ public function get($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -216,7 +216,7 @@ public function get($path, $parameters = null, $requestOptions = [])
      * @param string $startDate The lower bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $endDate The upper bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetAverageClickPositionResponse
      */
@@ -259,6 +259,7 @@ public function getAverageClickPosition(
 
         $resourcePath = '/2/clicks/averageClickPosition';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -329,11 +330,10 @@ public function getAverageClickPosition(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -347,7 +347,7 @@ public function getAverageClickPosition(
      * @param string $startDate The lower bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $endDate The upper bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetClickPositionsResponse
      */
@@ -390,6 +390,7 @@ public function getClickPositions(
 
         $resourcePath = '/2/clicks/positions';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -460,11 +461,10 @@ public function getClickPositions(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -478,7 +478,7 @@ public function getClickPositions(
      * @param string $startDate The lower bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $endDate The upper bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetClickThroughRateResponse
      */
@@ -521,6 +521,7 @@ public function getClickThroughRate(
 
         $resourcePath = '/2/clicks/clickThroughRate';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -591,11 +592,10 @@ public function getClickThroughRate(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -609,7 +609,7 @@ public function getClickThroughRate(
      * @param string $startDate The lower bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $endDate The upper bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetConversationRateResponse
      */
@@ -652,6 +652,7 @@ public function getConversationRate(
 
         $resourcePath = '/2/conversions/conversionRate';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -722,11 +723,10 @@ public function getConversationRate(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -740,7 +740,7 @@ public function getConversationRate(
      * @param string $startDate The lower bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $endDate The upper bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetNoClickRateResponse
      */
@@ -783,6 +783,7 @@ public function getNoClickRate(
 
         $resourcePath = '/2/searches/noClickRate';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -853,11 +854,10 @@ public function getNoClickRate(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -871,7 +871,7 @@ public function getNoClickRate(
      * @param string $startDate The lower bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $endDate The upper bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetNoResultsRateResponse
      */
@@ -914,6 +914,7 @@ public function getNoResultsRate(
 
         $resourcePath = '/2/searches/noResultRate';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -984,11 +985,10 @@ public function getNoResultsRate(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1002,7 +1002,7 @@ public function getNoResultsRate(
      * @param string $startDate The lower bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $endDate The upper bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetSearchesCountResponse
      */
@@ -1045,6 +1045,7 @@ public function getSearchesCount(
 
         $resourcePath = '/2/searches/count';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -1115,11 +1116,10 @@ public function getSearchesCount(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1135,7 +1135,7 @@ public function getSearchesCount(
      * @param int $limit Number of records to return. Limit is the size of the page. (optional, default to 10)
      * @param int $offset Position of the starting record. Used for paging. 0 is the first record. (optional, default to 0)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetSearchesNoClicksResponse
      */
@@ -1180,6 +1180,7 @@ public function getSearchesNoClicks(
 
         $resourcePath = '/2/searches/noClicks';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -1284,11 +1285,10 @@ public function getSearchesNoClicks(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1304,7 +1304,7 @@ public function getSearchesNoClicks(
      * @param int $limit Number of records to return. Limit is the size of the page. (optional, default to 10)
      * @param int $offset Position of the starting record. Used for paging. 0 is the first record. (optional, default to 0)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetSearchesNoResultsResponse
      */
@@ -1349,6 +1349,7 @@ public function getSearchesNoResults(
 
         $resourcePath = '/2/searches/noResults';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -1453,11 +1454,10 @@ public function getSearchesNoResults(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1468,7 +1468,7 @@ public function getSearchesNoResults(
      * Get Analytics API status.
      *
      * @param string $index The index name to target. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetStatusResponse
      */
@@ -1483,6 +1483,7 @@ public function getStatus($index, $requestOptions = [])
 
         $resourcePath = '/2/status';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -1502,11 +1503,10 @@ public function getStatus($index, $requestOptions = [])
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1522,7 +1522,7 @@ public function getStatus($index, $requestOptions = [])
      * @param int $limit Number of records to return. Limit is the size of the page. (optional, default to 10)
      * @param int $offset Position of the starting record. Used for paging. 0 is the first record. (optional, default to 0)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetTopCountriesResponse
      */
@@ -1567,6 +1567,7 @@ public function getTopCountries(
 
         $resourcePath = '/2/countries';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -1671,11 +1672,10 @@ public function getTopCountries(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1692,7 +1692,7 @@ public function getTopCountries(
      * @param int $limit Number of records to return. Limit is the size of the page. (optional, default to 10)
      * @param int $offset Position of the starting record. Used for paging. 0 is the first record. (optional, default to 0)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetTopFilterAttributesResponse
      */
@@ -1738,6 +1738,7 @@ public function getTopFilterAttributes(
 
         $resourcePath = '/2/filters';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -1859,11 +1860,10 @@ public function getTopFilterAttributes(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1881,7 +1881,7 @@ public function getTopFilterAttributes(
      * @param int $limit Number of records to return. Limit is the size of the page. (optional, default to 10)
      * @param int $offset Position of the starting record. Used for paging. 0 is the first record. (optional, default to 0)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetTopFilterForAttributeResponse
      */
@@ -1937,6 +1937,7 @@ public function getTopFilterForAttribute(
 
         $resourcePath = '/2/filters/{attribute}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -2067,11 +2068,10 @@ public function getTopFilterForAttribute(
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2088,7 +2088,7 @@ public function getTopFilterForAttribute(
      * @param int $limit Number of records to return. Limit is the size of the page. (optional, default to 10)
      * @param int $offset Position of the starting record. Used for paging. 0 is the first record. (optional, default to 0)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetTopFiltersNoResultsResponse
      */
@@ -2134,6 +2134,7 @@ public function getTopFiltersNoResults(
 
         $resourcePath = '/2/filters/noResults';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -2255,11 +2256,10 @@ public function getTopFiltersNoResults(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2277,7 +2277,7 @@ public function getTopFiltersNoResults(
      * @param int $limit Number of records to return. Limit is the size of the page. (optional, default to 10)
      * @param int $offset Position of the starting record. Used for paging. 0 is the first record. (optional, default to 0)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetTopHitsResponse
      */
@@ -2324,6 +2324,7 @@ public function getTopHits(
 
         $resourcePath = '/2/hits';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -2462,11 +2463,10 @@ public function getTopHits(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2485,7 +2485,7 @@ public function getTopHits(
      * @param int $limit Number of records to return. Limit is the size of the page. (optional, default to 10)
      * @param int $offset Position of the starting record. Used for paging. 0 is the first record. (optional, default to 0)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetTopSearchesResponse
      */
@@ -2533,6 +2533,7 @@ public function getTopSearches(
 
         $resourcePath = '/2/searches';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -2688,11 +2689,10 @@ public function getTopSearches(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2706,7 +2706,7 @@ public function getTopSearches(
      * @param string $startDate The lower bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $endDate The upper bound timestamp (a date, a string like \&quot;2006-01-02\&quot;) of the period to analyze. (optional)
      * @param string $tags Filter metrics on the provided tags. Each tag must correspond to an analyticsTags set at search time. Multiple tags can be combined with the operators OR and AND. If a tag contains characters like spaces or parentheses, it should be URL encoded. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Analytics\GetUsersCountResponse
      */
@@ -2749,6 +2749,7 @@ public function getUsersCount(
 
         $resourcePath = '/2/users/count';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($index !== null) {
@@ -2819,11 +2820,10 @@ public function getUsersCount(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2836,7 +2836,7 @@ public function getUsersCount(
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -2855,6 +2855,7 @@ public function post(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -2882,11 +2883,11 @@ public function post(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2899,7 +2900,7 @@ public function post(
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -2918,6 +2919,7 @@ public function put(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -2945,11 +2947,11 @@ public function put(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2959,11 +2961,30 @@ public function put(
     private function sendRequest(
         $method,
         $resourcePath,
+        $headers,
         $queryParameters,
         $httpBody,
         $requestOptions
     ) {
-        $query = \GuzzleHttp\Psr7\Query::build($queryParameters);
+        if (!isset($requestOptions['headers'])) {
+            $requestOptions['headers'] = [];
+        }
+        if (!isset($requestOptions['queryParameters'])) {
+            $requestOptions['queryParameters'] = [];
+        }
+
+        $requestOptions['headers'] = array_merge(
+            $headers,
+            $requestOptions['headers']
+        );
+        $requestOptions['queryParameters'] = array_merge(
+            $queryParameters,
+            $requestOptions['queryParameters']
+        );
+
+        $query = \GuzzleHttp\Psr7\Query::build(
+            $requestOptions['queryParameters']
+        );
 
         if ($method === 'GET') {
             $request = $this->api->read(
diff --git a/clients/algoliasearch-client-php/lib/Api/InsightsClient.php b/clients/algoliasearch-client-php/lib/Api/InsightsClient.php
index b0dce86ed8..517657608b 100644
--- a/clients/algoliasearch-client-php/lib/Api/InsightsClient.php
+++ b/clients/algoliasearch-client-php/lib/Api/InsightsClient.php
@@ -103,7 +103,7 @@ public function getClientConfig()
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -118,6 +118,7 @@ public function del($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -142,11 +143,10 @@ public function del($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -158,7 +158,7 @@ public function del($path, $parameters = null, $requestOptions = [])
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -173,6 +173,7 @@ public function get($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -197,11 +198,10 @@ public function get($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -214,7 +214,7 @@ public function get($path, $parameters = null, $requestOptions = [])
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -233,6 +233,7 @@ public function post(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -260,11 +261,11 @@ public function post(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -279,7 +280,7 @@ public function post(
      *
      * @see \Algolia\AlgoliaSearch\Model\Insights\InsightEvents
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Insights\PushEventsResponse
      */
@@ -297,16 +298,17 @@ public function pushEvents($insightEvents, $requestOptions = [])
 
         $resourcePath = '/1/events';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($insightEvents)) {
             $httpBody = $insightEvents;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -319,7 +321,7 @@ public function pushEvents($insightEvents, $requestOptions = [])
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -338,6 +340,7 @@ public function put(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -365,11 +368,11 @@ public function put(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -379,11 +382,30 @@ public function put(
     private function sendRequest(
         $method,
         $resourcePath,
+        $headers,
         $queryParameters,
         $httpBody,
         $requestOptions
     ) {
-        $query = \GuzzleHttp\Psr7\Query::build($queryParameters);
+        if (!isset($requestOptions['headers'])) {
+            $requestOptions['headers'] = [];
+        }
+        if (!isset($requestOptions['queryParameters'])) {
+            $requestOptions['queryParameters'] = [];
+        }
+
+        $requestOptions['headers'] = array_merge(
+            $headers,
+            $requestOptions['headers']
+        );
+        $requestOptions['queryParameters'] = array_merge(
+            $queryParameters,
+            $requestOptions['queryParameters']
+        );
+
+        $query = \GuzzleHttp\Psr7\Query::build(
+            $requestOptions['queryParameters']
+        );
 
         if ($method === 'GET') {
             $request = $this->api->read(
diff --git a/clients/algoliasearch-client-php/lib/Api/PersonalizationClient.php b/clients/algoliasearch-client-php/lib/Api/PersonalizationClient.php
index f8834700e6..ad85a58443 100644
--- a/clients/algoliasearch-client-php/lib/Api/PersonalizationClient.php
+++ b/clients/algoliasearch-client-php/lib/Api/PersonalizationClient.php
@@ -104,7 +104,7 @@ public function getClientConfig()
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -119,6 +119,7 @@ public function del($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -143,11 +144,10 @@ public function del($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -158,7 +158,7 @@ public function del($path, $parameters = null, $requestOptions = [])
      * Delete a user profile.
      *
      * @param string $userToken userToken representing the user for which to fetch the Personalization profile. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Personalization\DeleteUserProfileResponse
      */
@@ -176,6 +176,7 @@ public function deleteUserProfile($userToken, $requestOptions = [])
 
         $resourcePath = '/1/profiles/{userToken}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -187,11 +188,10 @@ public function deleteUserProfile($userToken, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -203,7 +203,7 @@ public function deleteUserProfile($userToken, $requestOptions = [])
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -218,6 +218,7 @@ public function get($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -242,11 +243,10 @@ public function get($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -256,7 +256,7 @@ public function get($path, $parameters = null, $requestOptions = [])
     /**
      * Get the current strategy.
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Personalization\PersonalizationStrategyParams
      */
@@ -264,13 +264,13 @@ public function getPersonalizationStrategy($requestOptions = [])
     {
         $resourcePath = '/1/strategies/personalization';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -281,7 +281,7 @@ public function getPersonalizationStrategy($requestOptions = [])
      * Get a user profile.
      *
      * @param string $userToken userToken representing the user for which to fetch the Personalization profile. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Personalization\GetUserTokenResponse
      */
@@ -299,6 +299,7 @@ public function getUserTokenProfile($userToken, $requestOptions = [])
 
         $resourcePath = '/1/profiles/personalization/{userToken}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -310,11 +311,10 @@ public function getUserTokenProfile($userToken, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -327,7 +327,7 @@ public function getUserTokenProfile($userToken, $requestOptions = [])
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -346,6 +346,7 @@ public function post(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -373,11 +374,11 @@ public function post(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -390,7 +391,7 @@ public function post(
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -409,6 +410,7 @@ public function put(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -436,11 +438,11 @@ public function put(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -457,7 +459,7 @@ public function put(
      *
      * @see \Algolia\AlgoliaSearch\Model\Personalization\PersonalizationStrategyParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Personalization\SetPersonalizationStrategyResponse
      */
@@ -478,16 +480,17 @@ public function setPersonalizationStrategy(
 
         $resourcePath = '/1/strategies/personalization';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($personalizationStrategyParams)) {
             $httpBody = $personalizationStrategyParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -497,11 +500,30 @@ public function setPersonalizationStrategy(
     private function sendRequest(
         $method,
         $resourcePath,
+        $headers,
         $queryParameters,
         $httpBody,
         $requestOptions
     ) {
-        $query = \GuzzleHttp\Psr7\Query::build($queryParameters);
+        if (!isset($requestOptions['headers'])) {
+            $requestOptions['headers'] = [];
+        }
+        if (!isset($requestOptions['queryParameters'])) {
+            $requestOptions['queryParameters'] = [];
+        }
+
+        $requestOptions['headers'] = array_merge(
+            $headers,
+            $requestOptions['headers']
+        );
+        $requestOptions['queryParameters'] = array_merge(
+            $queryParameters,
+            $requestOptions['queryParameters']
+        );
+
+        $query = \GuzzleHttp\Psr7\Query::build(
+            $requestOptions['queryParameters']
+        );
 
         if ($method === 'GET') {
             $request = $this->api->read(
diff --git a/clients/algoliasearch-client-php/lib/Api/QuerySuggestionsClient.php b/clients/algoliasearch-client-php/lib/Api/QuerySuggestionsClient.php
index bbffc686a4..057f203bc7 100644
--- a/clients/algoliasearch-client-php/lib/Api/QuerySuggestionsClient.php
+++ b/clients/algoliasearch-client-php/lib/Api/QuerySuggestionsClient.php
@@ -106,7 +106,7 @@ public function getClientConfig()
      *
      * @see \Algolia\AlgoliaSearch\Model\QuerySuggestions\QuerySuggestionsIndexWithIndexParam
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\QuerySuggestions\SucessResponse
      */
@@ -127,16 +127,17 @@ public function createConfig(
 
         $resourcePath = '/1/configs';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($querySuggestionsIndexWithIndexParam)) {
             $httpBody = $querySuggestionsIndexWithIndexParam;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -148,7 +149,7 @@ public function createConfig(
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -163,6 +164,7 @@ public function del($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -187,11 +189,10 @@ public function del($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -202,7 +203,7 @@ public function del($path, $parameters = null, $requestOptions = [])
      * Delete a configuration.
      *
      * @param string $indexName The index in which to perform the request. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\QuerySuggestions\SucessResponse
      */
@@ -220,6 +221,7 @@ public function deleteConfig($indexName, $requestOptions = [])
 
         $resourcePath = '/1/configs/{indexName}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -231,11 +233,10 @@ public function deleteConfig($indexName, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -247,7 +248,7 @@ public function deleteConfig($indexName, $requestOptions = [])
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -262,6 +263,7 @@ public function get($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -286,11 +288,10 @@ public function get($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -300,7 +301,7 @@ public function get($path, $parameters = null, $requestOptions = [])
     /**
      * List configurations.
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\QuerySuggestions\QuerySuggestionsIndex[]
      */
@@ -308,13 +309,13 @@ public function getAllConfigs($requestOptions = [])
     {
         $resourcePath = '/1/configs';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -325,7 +326,7 @@ public function getAllConfigs($requestOptions = [])
      * Get a single configuration.
      *
      * @param string $indexName The index in which to perform the request. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\QuerySuggestions\QuerySuggestionsIndex
      */
@@ -343,6 +344,7 @@ public function getConfig($indexName, $requestOptions = [])
 
         $resourcePath = '/1/configs/{indexName}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -354,11 +356,10 @@ public function getConfig($indexName, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -369,7 +370,7 @@ public function getConfig($indexName, $requestOptions = [])
      * Get configuration status.
      *
      * @param string $indexName The index in which to perform the request. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\QuerySuggestions\Status
      */
@@ -387,6 +388,7 @@ public function getConfigStatus($indexName, $requestOptions = [])
 
         $resourcePath = '/1/configs/{indexName}/status';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -398,11 +400,10 @@ public function getConfigStatus($indexName, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -413,7 +414,7 @@ public function getConfigStatus($indexName, $requestOptions = [])
      * Get a log file.
      *
      * @param string $indexName The index in which to perform the request. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\QuerySuggestions\LogFile[]
      */
@@ -431,6 +432,7 @@ public function getLogFile($indexName, $requestOptions = [])
 
         $resourcePath = '/1/logs/{indexName}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -442,11 +444,10 @@ public function getLogFile($indexName, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -459,7 +460,7 @@ public function getLogFile($indexName, $requestOptions = [])
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -478,6 +479,7 @@ public function post(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -505,11 +507,11 @@ public function post(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -522,7 +524,7 @@ public function post(
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -541,6 +543,7 @@ public function put(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -568,11 +571,11 @@ public function put(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -590,7 +593,7 @@ public function put(
      *
      * @see \Algolia\AlgoliaSearch\Model\QuerySuggestions\QuerySuggestionsIndexParam
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\QuerySuggestions\SucessResponse
      */
@@ -621,6 +624,7 @@ public function updateConfig(
 
         $resourcePath = '/1/configs/{indexName}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -635,11 +639,11 @@ public function updateConfig(
         if (isset($querySuggestionsIndexParam)) {
             $httpBody = $querySuggestionsIndexParam;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -649,11 +653,30 @@ public function updateConfig(
     private function sendRequest(
         $method,
         $resourcePath,
+        $headers,
         $queryParameters,
         $httpBody,
         $requestOptions
     ) {
-        $query = \GuzzleHttp\Psr7\Query::build($queryParameters);
+        if (!isset($requestOptions['headers'])) {
+            $requestOptions['headers'] = [];
+        }
+        if (!isset($requestOptions['queryParameters'])) {
+            $requestOptions['queryParameters'] = [];
+        }
+
+        $requestOptions['headers'] = array_merge(
+            $headers,
+            $requestOptions['headers']
+        );
+        $requestOptions['queryParameters'] = array_merge(
+            $queryParameters,
+            $requestOptions['queryParameters']
+        );
+
+        $query = \GuzzleHttp\Psr7\Query::build(
+            $requestOptions['queryParameters']
+        );
 
         if ($method === 'GET') {
             $request = $this->api->read(
diff --git a/clients/algoliasearch-client-php/lib/Api/RecommendClient.php b/clients/algoliasearch-client-php/lib/Api/RecommendClient.php
index fbb0a0d7c3..daa86e59e4 100644
--- a/clients/algoliasearch-client-php/lib/Api/RecommendClient.php
+++ b/clients/algoliasearch-client-php/lib/Api/RecommendClient.php
@@ -103,7 +103,7 @@ public function getClientConfig()
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -118,6 +118,7 @@ public function del($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -142,11 +143,10 @@ public function del($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -158,7 +158,7 @@ public function del($path, $parameters = null, $requestOptions = [])
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -173,6 +173,7 @@ public function get($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -197,11 +198,10 @@ public function get($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -216,7 +216,7 @@ public function get($path, $parameters = null, $requestOptions = [])
      *
      * @see \Algolia\AlgoliaSearch\Model\Recommend\GetRecommendationsParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Recommend\GetRecommendationsResponse
      */
@@ -237,16 +237,17 @@ public function getRecommendations(
 
         $resourcePath = '/1/indexes/*/recommendations';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($getRecommendationsParams)) {
             $httpBody = $getRecommendationsParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -259,7 +260,7 @@ public function getRecommendations(
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -278,6 +279,7 @@ public function post(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -305,11 +307,11 @@ public function post(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -322,7 +324,7 @@ public function post(
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -341,6 +343,7 @@ public function put(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -368,11 +371,11 @@ public function put(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -382,11 +385,30 @@ public function put(
     private function sendRequest(
         $method,
         $resourcePath,
+        $headers,
         $queryParameters,
         $httpBody,
         $requestOptions
     ) {
-        $query = \GuzzleHttp\Psr7\Query::build($queryParameters);
+        if (!isset($requestOptions['headers'])) {
+            $requestOptions['headers'] = [];
+        }
+        if (!isset($requestOptions['queryParameters'])) {
+            $requestOptions['queryParameters'] = [];
+        }
+
+        $requestOptions['headers'] = array_merge(
+            $headers,
+            $requestOptions['headers']
+        );
+        $requestOptions['queryParameters'] = array_merge(
+            $queryParameters,
+            $requestOptions['queryParameters']
+        );
+
+        $query = \GuzzleHttp\Psr7\Query::build(
+            $requestOptions['queryParameters']
+        );
 
         if ($method === 'GET') {
             $request = $this->api->read(
diff --git a/clients/algoliasearch-client-php/lib/Api/SearchClient.php b/clients/algoliasearch-client-php/lib/Api/SearchClient.php
index e89c48e5ac..62c9acd2f3 100644
--- a/clients/algoliasearch-client-php/lib/Api/SearchClient.php
+++ b/clients/algoliasearch-client-php/lib/Api/SearchClient.php
@@ -112,7 +112,7 @@ public function getClientConfig()
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\ApiKey
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\AddApiKeyResponse
      */
@@ -127,16 +127,17 @@ public function addApiKey($apiKey, $requestOptions = [])
 
         $resourcePath = '/1/keys';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($apiKey)) {
             $httpBody = $apiKey;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -149,7 +150,7 @@ public function addApiKey($apiKey, $requestOptions = [])
      * @param string $indexName The index in which to perform the request. (required)
      * @param string $objectID Unique identifier of an object. (required)
      * @param array $body The Algolia object. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtWithObjectIdResponse
      */
@@ -186,6 +187,7 @@ public function addOrUpdateObject(
 
         $resourcePath = '/1/indexes/{indexName}/{objectID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -209,11 +211,11 @@ public function addOrUpdateObject(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -227,7 +229,7 @@ public function addOrUpdateObject(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\Source
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\CreatedAtResponse
      */
@@ -242,16 +244,17 @@ public function appendSource($source, $requestOptions = [])
 
         $resourcePath = '/1/security/sources/append';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($source)) {
             $httpBody = $source;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -267,7 +270,7 @@ public function appendSource($source, $requestOptions = [])
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\AssignUserIdParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\CreatedAtResponse
      */
@@ -303,17 +306,18 @@ public function assignUserId(
 
         $resourcePath = '/1/clusters/mapping';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($assignUserIdParams)) {
             $httpBody = $assignUserIdParams;
         }
-        $queryParameters['X-Algolia-User-ID'] = $xAlgoliaUserID;
-        $requestOptions += $queryParameters;
+        $headers['X-Algolia-User-ID'] = $xAlgoliaUserID;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -329,7 +333,7 @@ public function assignUserId(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\BatchWriteParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\BatchResponse
      */
@@ -356,6 +360,7 @@ public function batch($indexName, $batchWriteParams, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}/batch';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -370,11 +375,11 @@ public function batch($indexName, $batchWriteParams, $requestOptions = [])
         if (isset($batchWriteParams)) {
             $httpBody = $batchWriteParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -391,7 +396,7 @@ public function batch($indexName, $batchWriteParams, $requestOptions = [])
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\BatchAssignUserIdsParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\CreatedAtResponse
      */
@@ -428,17 +433,18 @@ public function batchAssignUserIds(
 
         $resourcePath = '/1/clusters/mapping/batch';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($batchAssignUserIdsParams)) {
             $httpBody = $batchAssignUserIdsParams;
         }
-        $queryParameters['X-Algolia-User-ID'] = $xAlgoliaUserID;
-        $requestOptions += $queryParameters;
+        $headers['X-Algolia-User-ID'] = $xAlgoliaUserID;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -455,7 +461,7 @@ public function batchAssignUserIds(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\BatchDictionaryEntriesParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -486,6 +492,7 @@ public function batchDictionaryEntries(
 
         $resourcePath = '/1/dictionaries/{dictionaryName}/batch';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -500,11 +507,11 @@ public function batchDictionaryEntries(
         if (isset($batchDictionaryEntriesParams)) {
             $httpBody = $batchDictionaryEntriesParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -518,7 +525,7 @@ public function batchDictionaryEntries(
      * @param array $rule rule (required)
      * @param bool $forwardToReplicas When true, changes are also propagated to replicas of the given indexName. (optional)
      * @param bool $clearExistingRules When true, existing Rules are cleared before adding this batch. When false, existing Rules are kept. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -547,6 +554,7 @@ public function batchRules(
 
         $resourcePath = '/1/indexes/{indexName}/rules/batch';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($forwardToReplicas !== null) {
@@ -595,11 +603,11 @@ public function batchRules(
         if (isset($rule)) {
             $httpBody = $rule;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -616,7 +624,7 @@ public function batchRules(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\BrowseRequest
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\BrowseResponse
      */
@@ -637,6 +645,7 @@ public function browse(
 
         $resourcePath = '/1/indexes/{indexName}/browse';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -651,11 +660,11 @@ public function browse(
         if (isset($browseRequest)) {
             $httpBody = $browseRequest;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -667,7 +676,7 @@ public function browse(
      *
      * @param string $indexName The index in which to perform the request. (required)
      * @param bool $forwardToReplicas When true, changes are also propagated to replicas of the given indexName. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -688,6 +697,7 @@ public function clearAllSynonyms(
 
         $resourcePath = '/1/indexes/{indexName}/synonyms/clear';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($forwardToReplicas !== null) {
@@ -716,11 +726,10 @@ public function clearAllSynonyms(
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -731,7 +740,7 @@ public function clearAllSynonyms(
      * Clear all objects from an index.
      *
      * @param string $indexName The index in which to perform the request. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -749,6 +758,7 @@ public function clearObjects($indexName, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}/clear';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -760,11 +770,10 @@ public function clearObjects($indexName, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -776,7 +785,7 @@ public function clearObjects($indexName, $requestOptions = [])
      *
      * @param string $indexName The index in which to perform the request. (required)
      * @param bool $forwardToReplicas When true, changes are also propagated to replicas of the given indexName. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -797,6 +806,7 @@ public function clearRules(
 
         $resourcePath = '/1/indexes/{indexName}/rules/clear';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($forwardToReplicas !== null) {
@@ -825,11 +835,10 @@ public function clearRules(
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -841,7 +850,7 @@ public function clearRules(
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -856,6 +865,7 @@ public function del($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -880,11 +890,10 @@ public function del($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -895,7 +904,7 @@ public function del($path, $parameters = null, $requestOptions = [])
      * Delete an API key.
      *
      * @param string $key API Key string. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\DeleteApiKeyResponse
      */
@@ -910,6 +919,7 @@ public function deleteApiKey($key, $requestOptions = [])
 
         $resourcePath = '/1/keys/{key}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -921,11 +931,10 @@ public function deleteApiKey($key, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -940,7 +949,7 @@ public function deleteApiKey($key, $requestOptions = [])
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\SearchParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\DeletedAtResponse
      */
@@ -967,6 +976,7 @@ public function deleteBy($indexName, $searchParams, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}/deleteByQuery';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -981,11 +991,11 @@ public function deleteBy($indexName, $searchParams, $requestOptions = [])
         if (isset($searchParams)) {
             $httpBody = $searchParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -996,7 +1006,7 @@ public function deleteBy($indexName, $searchParams, $requestOptions = [])
      * Delete index.
      *
      * @param string $indexName The index in which to perform the request. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\DeletedAtResponse
      */
@@ -1014,6 +1024,7 @@ public function deleteIndex($indexName, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -1025,11 +1036,10 @@ public function deleteIndex($indexName, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1041,7 +1051,7 @@ public function deleteIndex($indexName, $requestOptions = [])
      *
      * @param string $indexName The index in which to perform the request. (required)
      * @param string $objectID Unique identifier of an object. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\DeletedAtResponse
      */
@@ -1068,6 +1078,7 @@ public function deleteObject($indexName, $objectID, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}/{objectID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -1088,11 +1099,10 @@ public function deleteObject($indexName, $objectID, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1105,7 +1115,7 @@ public function deleteObject($indexName, $objectID, $requestOptions = [])
      * @param string $indexName The index in which to perform the request. (required)
      * @param string $objectID Unique identifier of an object. (required)
      * @param bool $forwardToReplicas When true, changes are also propagated to replicas of the given indexName. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -1136,6 +1146,7 @@ public function deleteRule(
 
         $resourcePath = '/1/indexes/{indexName}/rules/{objectID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($forwardToReplicas !== null) {
@@ -1173,11 +1184,10 @@ public function deleteRule(
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1188,7 +1198,7 @@ public function deleteRule(
      * Remove a single source.
      *
      * @param string $source The IP range of the source. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\DeleteSourceResponse
      */
@@ -1203,6 +1213,7 @@ public function deleteSource($source, $requestOptions = [])
 
         $resourcePath = '/1/security/sources/{source}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -1214,11 +1225,10 @@ public function deleteSource($source, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1231,7 +1241,7 @@ public function deleteSource($source, $requestOptions = [])
      * @param string $indexName The index in which to perform the request. (required)
      * @param string $objectID Unique identifier of an object. (required)
      * @param bool $forwardToReplicas When true, changes are also propagated to replicas of the given indexName. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\DeletedAtResponse
      */
@@ -1262,6 +1272,7 @@ public function deleteSynonym(
 
         $resourcePath = '/1/indexes/{indexName}/synonyms/{objectID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($forwardToReplicas !== null) {
@@ -1299,11 +1310,10 @@ public function deleteSynonym(
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1315,7 +1325,7 @@ public function deleteSynonym(
      *
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -1330,6 +1340,7 @@ public function get($path, $parameters = null, $requestOptions = [])
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -1354,11 +1365,10 @@ public function get($path, $parameters = null, $requestOptions = [])
             $resourcePath = str_replace('{path}', $path, $resourcePath);
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1369,7 +1379,7 @@ public function get($path, $parameters = null, $requestOptions = [])
      * Get an API key.
      *
      * @param string $key API Key string. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\Key
      */
@@ -1384,6 +1394,7 @@ public function getApiKey($key, $requestOptions = [])
 
         $resourcePath = '/1/keys/{key}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -1395,11 +1406,10 @@ public function getApiKey($key, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1409,7 +1419,7 @@ public function getApiKey($key, $requestOptions = [])
     /**
      * List available languages.
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|array<string,\Algolia\AlgoliaSearch\Model\Search\Languages>
      */
@@ -1417,13 +1427,13 @@ public function getDictionaryLanguages($requestOptions = [])
     {
         $resourcePath = '/1/dictionaries/*/languages';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1433,7 +1443,7 @@ public function getDictionaryLanguages($requestOptions = [])
     /**
      * Retrieve dictionaries settings.
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\GetDictionarySettingsResponse
      */
@@ -1441,13 +1451,13 @@ public function getDictionarySettings($requestOptions = [])
     {
         $resourcePath = '/1/dictionaries/*/settings';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1461,7 +1471,7 @@ public function getDictionarySettings($requestOptions = [])
      * @param int $length Maximum number of entries to retrieve. The maximum allowed value is 1000. (optional, default to 10)
      * @param string $indexName Index for which log entries should be retrieved. When omitted, log entries are retrieved across all indices. (optional)
      * @param array $type Type of log entries to retrieve. When omitted, all log entries are retrieved. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\GetLogsResponse
      */
@@ -1480,6 +1490,7 @@ public function getLogs(
 
         $resourcePath = '/1/logs';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($offset !== null) {
@@ -1550,11 +1561,10 @@ public function getLogs(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1567,7 +1577,7 @@ public function getLogs(
      * @param string $indexName The index in which to perform the request. (required)
      * @param string $objectID Unique identifier of an object. (required)
      * @param array $attributesToRetrieve List of attributes to retrieve. If not specified, all retrievable attributes are returned. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|array<string,string>
      */
@@ -1598,6 +1608,7 @@ public function getObject(
 
         $resourcePath = '/1/indexes/{indexName}/{objectID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($attributesToRetrieve !== null) {
@@ -1637,11 +1648,10 @@ public function getObject(
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1656,7 +1666,7 @@ public function getObject(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\GetObjectsParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\GetObjectsResponse
      */
@@ -1674,16 +1684,17 @@ public function getObjects($getObjectsParams, $requestOptions = [])
 
         $resourcePath = '/1/indexes/*/objects';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($getObjectsParams)) {
             $httpBody = $getObjectsParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1695,7 +1706,7 @@ public function getObjects($getObjectsParams, $requestOptions = [])
      *
      * @param string $indexName The index in which to perform the request. (required)
      * @param string $objectID Unique identifier of an object. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\Rule
      */
@@ -1722,6 +1733,7 @@ public function getRule($indexName, $objectID, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}/rules/{objectID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -1742,11 +1754,10 @@ public function getRule($indexName, $objectID, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1757,7 +1768,7 @@ public function getRule($indexName, $objectID, $requestOptions = [])
      * Retrieve settings of an index.
      *
      * @param string $indexName The index in which to perform the request. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\IndexSettings
      */
@@ -1775,6 +1786,7 @@ public function getSettings($indexName, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}/settings';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -1786,11 +1798,10 @@ public function getSettings($indexName, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1800,7 +1811,7 @@ public function getSettings($indexName, $requestOptions = [])
     /**
      * List all allowed sources.
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\Source[]
      */
@@ -1808,13 +1819,13 @@ public function getSources($requestOptions = [])
     {
         $resourcePath = '/1/security/sources';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1826,7 +1837,7 @@ public function getSources($requestOptions = [])
      *
      * @param string $indexName The index in which to perform the request. (required)
      * @param string $objectID Unique identifier of an object. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\SynonymHit
      */
@@ -1853,6 +1864,7 @@ public function getSynonym($indexName, $objectID, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}/synonyms/{objectID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -1873,11 +1885,10 @@ public function getSynonym($indexName, $objectID, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1889,7 +1900,7 @@ public function getSynonym($indexName, $objectID, $requestOptions = [])
      *
      * @param string $indexName The index in which to perform the request. (required)
      * @param int $taskID Unique identifier of an task. Numeric value (up to 64bits). (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\GetTaskResponse
      */
@@ -1913,6 +1924,7 @@ public function getTask($indexName, $taskID, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}/task/{taskID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -1933,11 +1945,10 @@ public function getTask($indexName, $taskID, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1947,7 +1958,7 @@ public function getTask($indexName, $taskID, $requestOptions = [])
     /**
      * Get top userID.
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\GetTopUserIdsResponse
      */
@@ -1955,13 +1966,13 @@ public function getTopUserIds($requestOptions = [])
     {
         $resourcePath = '/1/clusters/mapping/top';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -1972,7 +1983,7 @@ public function getTopUserIds($requestOptions = [])
      * Get userID.
      *
      * @param string $userID userID to assign. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UserId
      */
@@ -1992,6 +2003,7 @@ public function getUserId($userID, $requestOptions = [])
 
         $resourcePath = '/1/clusters/mapping/{userID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -2003,11 +2015,10 @@ public function getUserId($userID, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2018,7 +2029,7 @@ public function getUserId($userID, $requestOptions = [])
      * Get migration status.
      *
      * @param bool $getClusters Whether to get clusters or not. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\CreatedAtResponse
      */
@@ -2028,6 +2039,7 @@ public function hasPendingMappings(
     ) {
         $resourcePath = '/1/clusters/mapping/pending';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($getClusters !== null) {
@@ -2047,11 +2059,10 @@ public function hasPendingMappings(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2061,7 +2072,7 @@ public function hasPendingMappings(
     /**
      * List API Keys.
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\ListApiKeysResponse
      */
@@ -2069,13 +2080,13 @@ public function listApiKeys($requestOptions = [])
     {
         $resourcePath = '/1/keys';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2085,7 +2096,7 @@ public function listApiKeys($requestOptions = [])
     /**
      * List clusters.
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\ListClustersResponse
      */
@@ -2093,13 +2104,13 @@ public function listClusters($requestOptions = [])
     {
         $resourcePath = '/1/clusters';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2110,7 +2121,7 @@ public function listClusters($requestOptions = [])
      * List existing indexes.
      *
      * @param int $page Requested page (zero-based). When specified, will retrieve a specific page; the page size is implicitly set to 100. When null, will retrieve all indices (no pagination). (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\ListIndicesResponse
      */
@@ -2118,6 +2129,7 @@ public function listIndices($page = null, $requestOptions = [])
     {
         $resourcePath = '/1/indexes';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($page !== null) {
@@ -2137,11 +2149,10 @@ public function listIndices($page = null, $requestOptions = [])
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2153,7 +2164,7 @@ public function listIndices($page = null, $requestOptions = [])
      *
      * @param int $page Requested page (zero-based). When specified, will retrieve a specific page; the page size is implicitly set to 100. When null, will retrieve all indices (no pagination). (optional)
      * @param int $hitsPerPage Maximum number of objects to retrieve. (optional, default to 100)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\ListUserIdsResponse
      */
@@ -2164,6 +2175,7 @@ public function listUserIds(
     ) {
         $resourcePath = '/1/clusters/mapping';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($page !== null) {
@@ -2200,11 +2212,10 @@ public function listUserIds(
             }
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'GET',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2219,7 +2230,7 @@ public function listUserIds(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\BatchParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\MultipleBatchResponse
      */
@@ -2237,16 +2248,17 @@ public function multipleBatch($batchParams, $requestOptions = [])
 
         $resourcePath = '/1/indexes/*/batch';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($batchParams)) {
             $httpBody = $batchParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2262,7 +2274,7 @@ public function multipleBatch($batchParams, $requestOptions = [])
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\MultipleQueriesParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\MultipleQueriesResponse
      */
@@ -2283,16 +2295,17 @@ public function multipleQueries(
 
         $resourcePath = '/1/indexes/*/queries';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($multipleQueriesParams)) {
             $httpBody = $multipleQueriesParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2310,7 +2323,7 @@ public function multipleQueries(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\OperationIndexParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -2341,6 +2354,7 @@ public function operationIndex(
 
         $resourcePath = '/1/indexes/{indexName}/operation';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -2355,11 +2369,11 @@ public function operationIndex(
         if (isset($operationIndexParams)) {
             $httpBody = $operationIndexParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2373,7 +2387,7 @@ public function operationIndex(
      * @param string $objectID Unique identifier of an object. (required)
      * @param array $attributeOrBuiltInOperation List of attributes to update. (required)
      * @param bool $createIfNotExists Creates the record if it does not exist yet. (optional, default to true)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtWithObjectIdResponse
      */
@@ -2415,6 +2429,7 @@ public function partialUpdateObject(
 
         $resourcePath = '/1/indexes/{indexName}/{objectID}/partial';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($createIfNotExists !== null) {
@@ -2455,11 +2470,11 @@ public function partialUpdateObject(
         if (isset($attributeOrBuiltInOperation)) {
             $httpBody = $attributeOrBuiltInOperation;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2472,7 +2487,7 @@ public function partialUpdateObject(
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -2491,6 +2506,7 @@ public function post(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -2518,11 +2534,11 @@ public function post(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2535,7 +2551,7 @@ public function post(
      * @param string $path The path of the API endpoint to target, anything after the /1 needs to be specified. (required)
      * @param array $parameters Query parameters to be applied to the current query. (optional)
      * @param array $body The parameters to send with the custom request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|object
      */
@@ -2554,6 +2570,7 @@ public function put(
 
         $resourcePath = '/1{path}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($parameters !== null) {
@@ -2581,11 +2598,11 @@ public function put(
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2596,7 +2613,7 @@ public function put(
      * Remove userID.
      *
      * @param string $userID userID to assign. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\RemoveUserIdResponse
      */
@@ -2616,6 +2633,7 @@ public function removeUserId($userID, $requestOptions = [])
 
         $resourcePath = '/1/clusters/mapping/{userID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -2627,11 +2645,10 @@ public function removeUserId($userID, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'DELETE',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2642,7 +2659,7 @@ public function removeUserId($userID, $requestOptions = [])
      * Replace all allowed sources.
      *
      * @param array $source The sources to allow. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\ReplaceSourceResponse
      */
@@ -2657,16 +2674,17 @@ public function replaceSources($source, $requestOptions = [])
 
         $resourcePath = '/1/security/sources';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($source)) {
             $httpBody = $source;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2677,7 +2695,7 @@ public function replaceSources($source, $requestOptions = [])
      * Restore an API key.
      *
      * @param string $key API Key string. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\AddApiKeyResponse
      */
@@ -2692,6 +2710,7 @@ public function restoreApiKey($key, $requestOptions = [])
 
         $resourcePath = '/1/keys/{key}/restore';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -2703,11 +2722,10 @@ public function restoreApiKey($key, $requestOptions = [])
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2719,7 +2737,7 @@ public function restoreApiKey($key, $requestOptions = [])
      *
      * @param string $indexName The index in which to perform the request. (required)
      * @param array $body The Algolia record. (required)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\SaveObjectResponse
      */
@@ -2743,6 +2761,7 @@ public function saveObject($indexName, $body, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -2757,11 +2776,11 @@ public function saveObject($indexName, $body, $requestOptions = [])
         if (isset($body)) {
             $httpBody = $body;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2784,7 +2803,7 @@ public function saveObject($indexName, $body, $requestOptions = [])
      * @see \Algolia\AlgoliaSearch\Model\Search\Rule
      *
      * @param bool $forwardToReplicas When true, changes are also propagated to replicas of the given indexName. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedRuleResponse
      */
@@ -2822,6 +2841,7 @@ public function saveRule(
 
         $resourcePath = '/1/indexes/{indexName}/rules/{objectID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($forwardToReplicas !== null) {
@@ -2862,11 +2882,11 @@ public function saveRule(
         if (isset($rule)) {
             $httpBody = $rule;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2892,7 +2912,7 @@ public function saveRule(
      * @see \Algolia\AlgoliaSearch\Model\Search\SynonymHit
      *
      * @param bool $forwardToReplicas When true, changes are also propagated to replicas of the given indexName. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\SaveSynonymResponse
      */
@@ -2933,6 +2953,7 @@ public function saveSynonym(
 
         $resourcePath = '/1/indexes/{indexName}/synonyms/{objectID}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($forwardToReplicas !== null) {
@@ -2973,11 +2994,11 @@ public function saveSynonym(
         if (isset($synonymHit)) {
             $httpBody = $synonymHit;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -2991,7 +3012,7 @@ public function saveSynonym(
      * @param array $synonymHit synonymHit (required)
      * @param bool $forwardToReplicas When true, changes are also propagated to replicas of the given indexName. (optional)
      * @param bool $replaceExistingSynonyms Replace all synonyms of the index with the ones sent with this request. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -3023,6 +3044,7 @@ public function saveSynonyms(
 
         $resourcePath = '/1/indexes/{indexName}/synonyms/batch';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($forwardToReplicas !== null) {
@@ -3073,11 +3095,11 @@ public function saveSynonyms(
         if (isset($synonymHit)) {
             $httpBody = $synonymHit;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -3092,7 +3114,7 @@ public function saveSynonyms(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\SearchParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\SearchResponse
      */
@@ -3119,6 +3141,7 @@ public function search($indexName, $searchParams, $requestOptions = [])
 
         $resourcePath = '/1/indexes/{indexName}/query';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -3133,11 +3156,11 @@ public function search($indexName, $searchParams, $requestOptions = [])
         if (isset($searchParams)) {
             $httpBody = $searchParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -3156,7 +3179,7 @@ public function search($indexName, $searchParams, $requestOptions = [])
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\SearchDictionaryEntriesParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -3187,6 +3210,7 @@ public function searchDictionaryEntries(
 
         $resourcePath = '/1/dictionaries/{dictionaryName}/search';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -3201,11 +3225,11 @@ public function searchDictionaryEntries(
         if (isset($searchDictionaryEntriesParams)) {
             $httpBody = $searchDictionaryEntriesParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -3224,7 +3248,7 @@ public function searchDictionaryEntries(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\SearchForFacetValuesRequest
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\SearchForFacetValuesResponse
      */
@@ -3255,6 +3279,7 @@ public function searchForFacetValues(
 
         $resourcePath = '/1/indexes/{indexName}/facets/{facetName}/query';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -3278,11 +3303,11 @@ public function searchForFacetValues(
         if (isset($searchForFacetValuesRequest)) {
             $httpBody = $searchForFacetValuesRequest;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -3304,7 +3329,7 @@ public function searchForFacetValues(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\SearchRulesParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\SearchRulesResponse
      */
@@ -3334,6 +3359,7 @@ public function searchRules(
 
         $resourcePath = '/1/indexes/{indexName}/rules/search';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -3348,11 +3374,11 @@ public function searchRules(
         if (isset($searchRulesParams)) {
             $httpBody = $searchRulesParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -3367,7 +3393,7 @@ public function searchRules(
      * @param array $type Only search for specific types of synonyms. (optional)
      * @param int $page Requested page (zero-based). When specified, will retrieve a specific page; the page size is implicitly set to 100. When null, will retrieve all indices (no pagination). (optional, default to 0)
      * @param int $hitsPerPage Maximum number of objects to retrieve. (optional, default to 100)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\SearchSynonymsResponse
      */
@@ -3391,6 +3417,7 @@ public function searchSynonyms(
 
         $resourcePath = '/1/indexes/{indexName}/synonyms/search';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($query !== null) {
@@ -3470,11 +3497,10 @@ public function searchSynonyms(
             );
         }
 
-        $requestOptions += $queryParameters;
-
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -3492,7 +3518,7 @@ public function searchSynonyms(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\SearchUserIdsParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\SearchUserIdsResponse
      */
@@ -3511,16 +3537,17 @@ public function searchUserIds($searchUserIdsParams, $requestOptions = [])
 
         $resourcePath = '/1/clusters/mapping/search';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($searchUserIdsParams)) {
             $httpBody = $searchUserIdsParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'POST',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -3535,7 +3562,7 @@ public function searchUserIds($searchUserIdsParams, $requestOptions = [])
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\DictionarySettingsParams
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -3556,16 +3583,17 @@ public function setDictionarySettings(
 
         $resourcePath = '/1/dictionaries/*/settings';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if (isset($dictionarySettingsParams)) {
             $httpBody = $dictionarySettingsParams;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -3581,7 +3609,7 @@ public function setDictionarySettings(
      * @see \Algolia\AlgoliaSearch\Model\Search\IndexSettings
      *
      * @param bool $forwardToReplicas When true, changes are also propagated to replicas of the given indexName. (optional)
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdatedAtResponse
      */
@@ -3612,6 +3640,7 @@ public function setSettings(
 
         $resourcePath = '/1/indexes/{indexName}/settings';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         if ($forwardToReplicas !== null) {
@@ -3643,11 +3672,11 @@ public function setSettings(
         if (isset($indexSettings)) {
             $httpBody = $indexSettings;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -3670,7 +3699,7 @@ public function setSettings(
      *
      * @see \Algolia\AlgoliaSearch\Model\Search\ApiKey
      *
-     * @param array $requestOptions Request Options
+     * @param array $requestOptions the requestOptions to send along with the query, they will be merged with the transporter requestOptions
      *
      * @return array<string, mixed>|\Algolia\AlgoliaSearch\Model\Search\UpdateApiKeyResponse
      */
@@ -3691,6 +3720,7 @@ public function updateApiKey($key, $apiKey, $requestOptions = [])
 
         $resourcePath = '/1/keys/{key}';
         $queryParameters = [];
+        $headers = [];
         $httpBody = [];
 
         // path params
@@ -3705,11 +3735,11 @@ public function updateApiKey($key, $apiKey, $requestOptions = [])
         if (isset($apiKey)) {
             $httpBody = $apiKey;
         }
-        $requestOptions += $queryParameters;
 
         return $this->sendRequest(
             'PUT',
             $resourcePath,
+            $headers,
             $queryParameters,
             $httpBody,
             $requestOptions
@@ -3719,11 +3749,30 @@ public function updateApiKey($key, $apiKey, $requestOptions = [])
     private function sendRequest(
         $method,
         $resourcePath,
+        $headers,
         $queryParameters,
         $httpBody,
         $requestOptions
     ) {
-        $query = \GuzzleHttp\Psr7\Query::build($queryParameters);
+        if (!isset($requestOptions['headers'])) {
+            $requestOptions['headers'] = [];
+        }
+        if (!isset($requestOptions['queryParameters'])) {
+            $requestOptions['queryParameters'] = [];
+        }
+
+        $requestOptions['headers'] = array_merge(
+            $headers,
+            $requestOptions['headers']
+        );
+        $requestOptions['queryParameters'] = array_merge(
+            $queryParameters,
+            $requestOptions['queryParameters']
+        );
+
+        $query = \GuzzleHttp\Psr7\Query::build(
+            $requestOptions['queryParameters']
+        );
 
         if ($method === 'GET') {
             $request = $this->api->read(
diff --git a/clients/algoliasearch-client-php/lib/RequestOptions/RequestOptionsFactory.php b/clients/algoliasearch-client-php/lib/RequestOptions/RequestOptionsFactory.php
index 3b7a14f48e..ecf9baebec 100644
--- a/clients/algoliasearch-client-php/lib/RequestOptions/RequestOptionsFactory.php
+++ b/clients/algoliasearch-client-php/lib/RequestOptions/RequestOptionsFactory.php
@@ -50,8 +50,7 @@ private function normalize($options)
             'headers' => [
                 'X-Algolia-Application-Id' => $this->config->getAppId(),
                 'X-Algolia-API-Key' => $this->config->getAlgoliaApiKey(),
-                'User-Agent' =>
-                    $this->config->getUserAgent() !== null
+                'User-Agent' => $this->config->getUserAgent() !== null
                         ? $this->config->getUserAgent()
                         : UserAgent::get(),
                 'Content-Type' => 'application/json',