diff --git a/openapi-config.yml b/openapi-config.yml
index 1a7dbb2..a8ba745 100644
--- a/openapi-config.yml
+++ b/openapi-config.yml
@@ -12,13 +12,4 @@ additionalProperties:
   invokerPackage: com.squidex.api.core
   modelPackage: com.squidex.api.types
   useRuntimeException: true
-  useSingleRequestParameter: true
-
-nameMappings:
-  file2: uploadFile
-  X-Fields: fields
-  X-Flatten: flatten
-  X-Languages: languages
-  X-NoSlowTotal: noSlowTotal
-  X-NoTotal: noTotal
-  X-Unpublished: unpublished
\ No newline at end of file
+  useSingleRequestParameter: true
\ No newline at end of file
diff --git a/src/main/java/com/squidex/api/core/api/AssetsApi.java b/src/main/java/com/squidex/api/core/api/AssetsApi.java
index 228ba58..c2df53f 100644
--- a/src/main/java/com/squidex/api/core/api/AssetsApi.java
+++ b/src/main/java/com/squidex/api/core/api/AssetsApi.java
@@ -2320,11 +2320,11 @@ private okhttp3.Call getAssetsCall(String parentId, String ids, String q, BigDec
         }
 
         if (noTotal != null) {
-            localVarHeaderParams.put("noTotal", localVarApiClient.parameterToString(noTotal));
+            localVarHeaderParams.put("X-NoTotal", localVarApiClient.parameterToString(noTotal));
         }
 
         if (noSlowTotal != null) {
-            localVarHeaderParams.put("noSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
+            localVarHeaderParams.put("X-NoSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
         }
 
         final String[] localVarAccepts = {
@@ -2580,11 +2580,11 @@ private okhttp3.Call getAssetsPostCall(QueryDto queryDto, Boolean noTotal, Boole
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (noTotal != null) {
-            localVarHeaderParams.put("noTotal", localVarApiClient.parameterToString(noTotal));
+            localVarHeaderParams.put("X-NoTotal", localVarApiClient.parameterToString(noTotal));
         }
 
         if (noSlowTotal != null) {
-            localVarHeaderParams.put("noSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
+            localVarHeaderParams.put("X-NoSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
         }
 
         final String[] localVarAccepts = {
diff --git a/src/main/java/com/squidex/api/core/api/ContentsApi.java b/src/main/java/com/squidex/api/core/api/ContentsApi.java
index 0ddfe5d..bb1e95b 100644
--- a/src/main/java/com/squidex/api/core/api/ContentsApi.java
+++ b/src/main/java/com/squidex/api/core/api/ContentsApi.java
@@ -289,11 +289,11 @@ private okhttp3.Call createDraftCall(String schema, String id, Boolean unpublish
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         final String[] localVarAccepts = {
@@ -697,11 +697,11 @@ private okhttp3.Call deleteContentStatusCall(String schema, String id, Boolean u
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         final String[] localVarAccepts = {
@@ -903,11 +903,11 @@ private okhttp3.Call deleteVersionCall(String schema, String id, Boolean unpubli
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         final String[] localVarAccepts = {
@@ -1113,19 +1113,19 @@ private okhttp3.Call getContentCall(String schema, String id, Long version, Stri
         }
 
         if (fields != null) {
-            localVarHeaderParams.put("fields", localVarApiClient.parameterToString(fields));
+            localVarHeaderParams.put("X-Fields", localVarApiClient.parameterToString(fields));
         }
 
         if (flatten != null) {
-            localVarHeaderParams.put("flatten", localVarApiClient.parameterToString(flatten));
+            localVarHeaderParams.put("X-Flatten", localVarApiClient.parameterToString(flatten));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         final String[] localVarAccepts = {
@@ -1528,11 +1528,11 @@ private okhttp3.Call getContentVersionCall(String schema, String id, Integer ver
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         final String[] localVarAccepts = {
@@ -1776,27 +1776,27 @@ private okhttp3.Call getContentsCall(String schema, String ids, String q, String
         }
 
         if (fields != null) {
-            localVarHeaderParams.put("fields", localVarApiClient.parameterToString(fields));
+            localVarHeaderParams.put("X-Fields", localVarApiClient.parameterToString(fields));
         }
 
         if (flatten != null) {
-            localVarHeaderParams.put("flatten", localVarApiClient.parameterToString(flatten));
+            localVarHeaderParams.put("X-Flatten", localVarApiClient.parameterToString(flatten));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         if (noSlowTotal != null) {
-            localVarHeaderParams.put("noSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
+            localVarHeaderParams.put("X-NoSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
         }
 
         if (noTotal != null) {
-            localVarHeaderParams.put("noTotal", localVarApiClient.parameterToString(noTotal));
+            localVarHeaderParams.put("X-NoTotal", localVarApiClient.parameterToString(noTotal));
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         final String[] localVarAccepts = {
@@ -2105,27 +2105,27 @@ private okhttp3.Call getContentsPostCall(String schema, QueryDto queryDto, Strin
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (fields != null) {
-            localVarHeaderParams.put("fields", localVarApiClient.parameterToString(fields));
+            localVarHeaderParams.put("X-Fields", localVarApiClient.parameterToString(fields));
         }
 
         if (flatten != null) {
-            localVarHeaderParams.put("flatten", localVarApiClient.parameterToString(flatten));
+            localVarHeaderParams.put("X-Flatten", localVarApiClient.parameterToString(flatten));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         if (noSlowTotal != null) {
-            localVarHeaderParams.put("noSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
+            localVarHeaderParams.put("X-NoSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
         }
 
         if (noTotal != null) {
-            localVarHeaderParams.put("noTotal", localVarApiClient.parameterToString(noTotal));
+            localVarHeaderParams.put("X-NoTotal", localVarApiClient.parameterToString(noTotal));
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         final String[] localVarAccepts = {
@@ -2376,27 +2376,27 @@ private okhttp3.Call getReferencesCall(String schema, String id, String q, Strin
         }
 
         if (fields != null) {
-            localVarHeaderParams.put("fields", localVarApiClient.parameterToString(fields));
+            localVarHeaderParams.put("X-Fields", localVarApiClient.parameterToString(fields));
         }
 
         if (flatten != null) {
-            localVarHeaderParams.put("flatten", localVarApiClient.parameterToString(flatten));
+            localVarHeaderParams.put("X-Flatten", localVarApiClient.parameterToString(flatten));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (noSlowTotal != null) {
-            localVarHeaderParams.put("noSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
+            localVarHeaderParams.put("X-NoSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
         }
 
         if (noTotal != null) {
-            localVarHeaderParams.put("noTotal", localVarApiClient.parameterToString(noTotal));
+            localVarHeaderParams.put("X-NoTotal", localVarApiClient.parameterToString(noTotal));
         }
 
         final String[] localVarAccepts = {
@@ -2652,27 +2652,27 @@ private okhttp3.Call getReferencingCall(String schema, String id, String q, Stri
         }
 
         if (fields != null) {
-            localVarHeaderParams.put("fields", localVarApiClient.parameterToString(fields));
+            localVarHeaderParams.put("X-Fields", localVarApiClient.parameterToString(fields));
         }
 
         if (flatten != null) {
-            localVarHeaderParams.put("flatten", localVarApiClient.parameterToString(flatten));
+            localVarHeaderParams.put("X-Flatten", localVarApiClient.parameterToString(flatten));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (noSlowTotal != null) {
-            localVarHeaderParams.put("noSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
+            localVarHeaderParams.put("X-NoSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
         }
 
         if (noTotal != null) {
-            localVarHeaderParams.put("noTotal", localVarApiClient.parameterToString(noTotal));
+            localVarHeaderParams.put("X-NoTotal", localVarApiClient.parameterToString(noTotal));
         }
 
         final String[] localVarAccepts = {
@@ -2924,11 +2924,11 @@ private okhttp3.Call patchContentCall(String schema, String id, Map<String, Map<
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         final String[] localVarAccepts = {
@@ -3150,11 +3150,11 @@ private okhttp3.Call postContentCall(String schema, Map<String, Map<String, Obje
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         final String[] localVarAccepts = {
@@ -3593,11 +3593,11 @@ private okhttp3.Call postUpsertContentCall(String schema, String id, Map<String,
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         final String[] localVarAccepts = {
@@ -3856,11 +3856,11 @@ private okhttp3.Call putContentCall(String schema, String id, Map<String, Map<St
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         final String[] localVarAccepts = {
@@ -4086,11 +4086,11 @@ private okhttp3.Call putContentDefaultsCall(String schema, String id, Boolean en
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         final String[] localVarAccepts = {
@@ -4303,11 +4303,11 @@ private okhttp3.Call putContentStatusCall(String schema, String id, ChangeStatus
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         final String[] localVarAccepts = {
@@ -4722,27 +4722,27 @@ private okhttp3.Call getAllContentsCall(String ids, OffsetDateTime scheduleFrom,
         }
 
         if (fields != null) {
-            localVarHeaderParams.put("fields", localVarApiClient.parameterToString(fields));
+            localVarHeaderParams.put("X-Fields", localVarApiClient.parameterToString(fields));
         }
 
         if (flatten != null) {
-            localVarHeaderParams.put("flatten", localVarApiClient.parameterToString(flatten));
+            localVarHeaderParams.put("X-Flatten", localVarApiClient.parameterToString(flatten));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         if (noSlowTotal != null) {
-            localVarHeaderParams.put("noSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
+            localVarHeaderParams.put("X-NoSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
         }
 
         if (noTotal != null) {
-            localVarHeaderParams.put("noTotal", localVarApiClient.parameterToString(noTotal));
+            localVarHeaderParams.put("X-NoTotal", localVarApiClient.parameterToString(noTotal));
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         final String[] localVarAccepts = {
@@ -5031,27 +5031,27 @@ private okhttp3.Call getAllContentsPostCall(AllContentsByPostDto allContentsByPo
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (fields != null) {
-            localVarHeaderParams.put("fields", localVarApiClient.parameterToString(fields));
+            localVarHeaderParams.put("X-Fields", localVarApiClient.parameterToString(fields));
         }
 
         if (flatten != null) {
-            localVarHeaderParams.put("flatten", localVarApiClient.parameterToString(flatten));
+            localVarHeaderParams.put("X-Flatten", localVarApiClient.parameterToString(flatten));
         }
 
         if (languages != null) {
-            localVarHeaderParams.put("languages", localVarApiClient.parameterToString(languages));
+            localVarHeaderParams.put("X-Languages", localVarApiClient.parameterToString(languages));
         }
 
         if (noSlowTotal != null) {
-            localVarHeaderParams.put("noSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
+            localVarHeaderParams.put("X-NoSlowTotal", localVarApiClient.parameterToString(noSlowTotal));
         }
 
         if (noTotal != null) {
-            localVarHeaderParams.put("noTotal", localVarApiClient.parameterToString(noTotal));
+            localVarHeaderParams.put("X-NoTotal", localVarApiClient.parameterToString(noTotal));
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         final String[] localVarAccepts = {
@@ -5300,7 +5300,7 @@ private okhttp3.Call getGraphQLCall(String theQueryString, String variables, Str
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         final String[] localVarAccepts = {
@@ -5513,7 +5513,7 @@ private okhttp3.Call getGraphQLBatchCall(String theQueryString, String variables
         }
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         final String[] localVarAccepts = {
@@ -5714,7 +5714,7 @@ private okhttp3.Call postGraphQLCall(Boolean unpublished, Object body, final Api
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         final String[] localVarAccepts = {
@@ -5899,7 +5899,7 @@ private okhttp3.Call postGraphQLBatchCall(Boolean unpublished, Object body, fina
         Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
         if (unpublished != null) {
-            localVarHeaderParams.put("unpublished", localVarApiClient.parameterToString(unpublished));
+            localVarHeaderParams.put("X-Unpublished", localVarApiClient.parameterToString(unpublished));
         }
 
         final String[] localVarAccepts = {
diff --git a/templates/api.mustache b/templates/api.mustache
index eb62334..a417e00 100644
--- a/templates/api.mustache
+++ b/templates/api.mustache
@@ -184,14 +184,14 @@ public class {{classname}} {
         {{/constantParams}}
         {{#headerParams}}
         if ({{paramName}} != null) {
-            localVarHeaderParams.put("{{baseName}}", localVarApiClient.parameterToString({{paramName}}));
+            localVarHeaderParams.put("{{vendorExtensions.x-header-name}}", localVarApiClient.parameterToString({{paramName}}));
         }
 
         {{/headerParams}}
         {{#constantParams}}
         {{#isHeaderParam}}
         // Set client side default value of Header Param "{{baseName}}".
-        localVarHeaderParams.put("{{baseName}}", {{#_enum}}"{{{.}}}"{{/_enum}});
+        localVarHeaderParams.put("{{vendorExtensions.x-header-name}}", {{#_enum}}"{{{.}}}"{{/_enum}});
 
         {{/isHeaderParam}}
         {{/constantParams}}