diff --git a/samples/client/petstore/kotlin-string/docs/PetApi.md b/samples/client/petstore/kotlin-string/docs/PetApi.md
index 9c09efacf7d..ea93e174527 100644
--- a/samples/client/petstore/kotlin-string/docs/PetApi.md
+++ b/samples/client/petstore/kotlin-string/docs/PetApi.md
@@ -51,7 +51,9 @@ null (empty response body)
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -97,7 +99,9 @@ null (empty response body)
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -144,7 +148,9 @@ Name | Type | Description  | Notes
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -191,7 +197,9 @@ Name | Type | Description  | Notes
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -238,7 +246,10 @@ Name | Type | Description  | Notes
 
 ### Authorization
 
-[api_key](../README.md#api_key)
+
+Configure api_key:
+    ApiClient.apiKey["api_key"] = ""
+    ApiClient.apiKeyPrefix["api_key"] = ""
 
 ### HTTP request headers
 
@@ -282,7 +293,9 @@ null (empty response body)
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -330,7 +343,9 @@ null (empty response body)
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -379,7 +394,9 @@ Name | Type | Description  | Notes
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
diff --git a/samples/client/petstore/kotlin-string/docs/StoreApi.md b/samples/client/petstore/kotlin-string/docs/StoreApi.md
index eed73ae300a..f4986041af8 100644
--- a/samples/client/petstore/kotlin-string/docs/StoreApi.md
+++ b/samples/client/petstore/kotlin-string/docs/StoreApi.md
@@ -92,7 +92,10 @@ This endpoint does not need any parameter.
 
 ### Authorization
 
-[api_key](../README.md#api_key)
+
+Configure api_key:
+    ApiClient.apiKey["api_key"] = ""
+    ApiClient.apiKeyPrefix["api_key"] = ""
 
 ### HTTP request headers
 
diff --git a/samples/client/petstore/kotlin-string/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt b/samples/client/petstore/kotlin-string/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
index 75a49d0fa43..e6ebe7982db 100644
--- a/samples/client/petstore/kotlin-string/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
+++ b/samples/client/petstore/kotlin-string/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
@@ -15,11 +15,18 @@ open class ApiClient(val baseUrl: String) {
     companion object {
         protected const val ContentType = "Content-Type"
         protected const val Accept = "Accept"
+        protected const val Authorization = "Authorization"
         protected const val JsonMediaType = "application/json"
         protected const val FormDataMediaType = "multipart/form-data"
         protected const val FormUrlEncMediaType = "application/x-www-form-urlencoded"
         protected const val XmlMediaType = "application/xml"
 
+        val apiKey: MutableMap<String, String> = mutableMapOf()
+        val apiKeyPrefix: MutableMap<String, String> = mutableMapOf()
+        var username: String? = null
+        var password: String? = null
+        var accessToken: String? = null
+
         @JvmStatic
         val client: OkHttpClient by lazy {
             builder.build()
@@ -65,9 +72,25 @@ open class ApiClient(val baseUrl: String) {
         }
     }
 
+    protected fun updateAuthParams(requestConfig: RequestConfig) {
+        if (requestConfig.headers["api_key"].isNullOrEmpty()) {
+            if (apiKeyPrefix["api_key"] != null) {
+                requestConfig.headers["api_key"] = apiKeyPrefix["api_key"] + " " + apiKey["api_key"]
+            } else {
+                requestConfig.headers["api_key"] = apiKey["api_key"]
+            }
+        }
+        if (requestConfig.headers[Authorization].isNullOrEmpty()) {
+            requestConfig.headers[Authorization] = "Bearer " + accessToken
+        }
+    }
+
     protected inline fun <reified T: Any?> request(requestConfig: RequestConfig, body : Any? = null): ApiInfrastructureResponse<T?> {
         val httpUrl = baseUrl.toHttpUrlOrNull() ?: throw IllegalStateException("baseUrl is invalid.")
 
+        // take authMethod from operation
+        updateAuthParams(requestConfig)
+
         val url = httpUrl.newBuilder()
             .addPathSegments(requestConfig.path.trimStart('/'))
             .apply {
diff --git a/samples/client/petstore/kotlin-threetenbp/docs/PetApi.md b/samples/client/petstore/kotlin-threetenbp/docs/PetApi.md
index 9c09efacf7d..ea93e174527 100644
--- a/samples/client/petstore/kotlin-threetenbp/docs/PetApi.md
+++ b/samples/client/petstore/kotlin-threetenbp/docs/PetApi.md
@@ -51,7 +51,9 @@ null (empty response body)
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -97,7 +99,9 @@ null (empty response body)
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -144,7 +148,9 @@ Name | Type | Description  | Notes
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -191,7 +197,9 @@ Name | Type | Description  | Notes
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -238,7 +246,10 @@ Name | Type | Description  | Notes
 
 ### Authorization
 
-[api_key](../README.md#api_key)
+
+Configure api_key:
+    ApiClient.apiKey["api_key"] = ""
+    ApiClient.apiKeyPrefix["api_key"] = ""
 
 ### HTTP request headers
 
@@ -282,7 +293,9 @@ null (empty response body)
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -330,7 +343,9 @@ null (empty response body)
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
@@ -379,7 +394,9 @@ Name | Type | Description  | Notes
 
 ### Authorization
 
-[petstore_auth](../README.md#petstore_auth)
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
 
 ### HTTP request headers
 
diff --git a/samples/client/petstore/kotlin-threetenbp/docs/StoreApi.md b/samples/client/petstore/kotlin-threetenbp/docs/StoreApi.md
index eed73ae300a..f4986041af8 100644
--- a/samples/client/petstore/kotlin-threetenbp/docs/StoreApi.md
+++ b/samples/client/petstore/kotlin-threetenbp/docs/StoreApi.md
@@ -92,7 +92,10 @@ This endpoint does not need any parameter.
 
 ### Authorization
 
-[api_key](../README.md#api_key)
+
+Configure api_key:
+    ApiClient.apiKey["api_key"] = ""
+    ApiClient.apiKeyPrefix["api_key"] = ""
 
 ### HTTP request headers
 
diff --git a/samples/client/petstore/kotlin-threetenbp/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt b/samples/client/petstore/kotlin-threetenbp/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
index 75a49d0fa43..e6ebe7982db 100644
--- a/samples/client/petstore/kotlin-threetenbp/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
+++ b/samples/client/petstore/kotlin-threetenbp/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
@@ -15,11 +15,18 @@ open class ApiClient(val baseUrl: String) {
     companion object {
         protected const val ContentType = "Content-Type"
         protected const val Accept = "Accept"
+        protected const val Authorization = "Authorization"
         protected const val JsonMediaType = "application/json"
         protected const val FormDataMediaType = "multipart/form-data"
         protected const val FormUrlEncMediaType = "application/x-www-form-urlencoded"
         protected const val XmlMediaType = "application/xml"
 
+        val apiKey: MutableMap<String, String> = mutableMapOf()
+        val apiKeyPrefix: MutableMap<String, String> = mutableMapOf()
+        var username: String? = null
+        var password: String? = null
+        var accessToken: String? = null
+
         @JvmStatic
         val client: OkHttpClient by lazy {
             builder.build()
@@ -65,9 +72,25 @@ open class ApiClient(val baseUrl: String) {
         }
     }
 
+    protected fun updateAuthParams(requestConfig: RequestConfig) {
+        if (requestConfig.headers["api_key"].isNullOrEmpty()) {
+            if (apiKeyPrefix["api_key"] != null) {
+                requestConfig.headers["api_key"] = apiKeyPrefix["api_key"] + " " + apiKey["api_key"]
+            } else {
+                requestConfig.headers["api_key"] = apiKey["api_key"]
+            }
+        }
+        if (requestConfig.headers[Authorization].isNullOrEmpty()) {
+            requestConfig.headers[Authorization] = "Bearer " + accessToken
+        }
+    }
+
     protected inline fun <reified T: Any?> request(requestConfig: RequestConfig, body : Any? = null): ApiInfrastructureResponse<T?> {
         val httpUrl = baseUrl.toHttpUrlOrNull() ?: throw IllegalStateException("baseUrl is invalid.")
 
+        // take authMethod from operation
+        updateAuthParams(requestConfig)
+
         val url = httpUrl.newBuilder()
             .addPathSegments(requestConfig.path.trimStart('/'))
             .apply {