From bb4af91bbd16d5d02d7ce844d7b70a347b67cff5 Mon Sep 17 00:00:00 2001
From: Javier Luque Sanabria <javils@users.noreply.github.com>
Date: Sun, 15 Dec 2019 11:26:37 +0100
Subject: [PATCH] Feature/kotlin/library/retrofit (#4518)

* Some clean code.

* Add support for retrofit2 in models and apis. Need work in ApiClient, but it's not urgent.

* Add ApiClient with retrofit2 support.

* Remove unnecessary package.

* Add scripts to generate samples.

* Generate sample of retrofit2

* Change toUpperCase to toUpperCase(Locale.ROOT) to fix compile.

* Added GSON library when it's needed

* Fix typo.

* Add some missing common files.

* Execute bin script.

* Remove copy&paste error in script.

* [kotlin] update outdated files

* Fix apis with no params.

* Add missing import in ApiClient

* Add support for CSV, SSV, TSV, PIPES, SPACES in retrofit 2 library.

* Fix package name.

* Execute kotlin-client-retrofit2.sh script.

* force rebuild.

* execute script again.

* Add missing imports from okhttp3.
@Deprecated has a message param that java not. Add it with a default message.

* Execute retrofit2 script.

* Rerun script.
---
 bin/kotlin-client-all.sh                      |   1 +
 bin/kotlin-client-retrofit2.sh                |  32 ++
 docs/generators/kotlin.md                     |   2 +-
 .../languages/KotlinClientCodegen.java        | 276 +++++++-----
 .../kotlin-client/build.gradle.mustache       |  17 +-
 .../kotlin-client/data_class.mustache         |   8 +-
 .../kotlin-client/data_class_opt_var.mustache |   4 +-
 .../kotlin-client/data_class_req_var.mustache |   4 +-
 .../kotlin-client/enum_class.mustache         |   8 +-
 .../libraries/retrofit2/api.mustache          |  38 ++
 .../libraries/retrofit2/bodyParams.mustache   |   1 +
 .../libraries/retrofit2/formParams.mustache   |   1 +
 .../libraries/retrofit2/headerParams.mustache |   1 +
 .../infrastructure/ApiClient.kt.mustache      |  43 ++
 .../ByteArrayAdapter.kt.mustache              |  50 +++
 .../CollectionFormats.kt.mustache             |  56 +++
 .../infrastructure/DateAdapter.kt.mustache    |  37 ++
 .../LocalDateAdapter.kt.mustache              |  63 +++
 .../LocalDateTimeAdapter.kt.mustache          |  63 +++
 .../infrastructure/Serializer.kt.mustache     |  45 ++
 .../infrastructure/UUIDAdapter.kt.mustache    |  51 +++
 .../libraries/retrofit2/pathParams.mustache   |   1 +
 .../libraries/retrofit2/queryParams.mustache  |   1 +
 .../.openapi-generator-ignore                 |  23 +
 .../.openapi-generator/VERSION                |   1 +
 .../petstore/kotlin-retrofit2/README.md       |  80 ++++
 .../petstore/kotlin-retrofit2/build.gradle    |  40 ++
 .../kotlin-retrofit2/docs/ApiResponse.md      |  12 +
 .../kotlin-retrofit2/docs/Category.md         |  11 +
 .../petstore/kotlin-retrofit2/docs/Order.md   |  22 +
 .../petstore/kotlin-retrofit2/docs/Pet.md     |  22 +
 .../petstore/kotlin-retrofit2/docs/PetApi.md  | 405 ++++++++++++++++++
 .../kotlin-retrofit2/docs/StoreApi.md         | 196 +++++++++
 .../petstore/kotlin-retrofit2/docs/Tag.md     |  11 +
 .../petstore/kotlin-retrofit2/docs/User.md    |  17 +
 .../petstore/kotlin-retrofit2/docs/UserApi.md | 376 ++++++++++++++++
 .../petstore/kotlin-retrofit2/settings.gradle |   2 +
 .../org/openapitools/client/apis/PetApi.kt    |  41 ++
 .../org/openapitools/client/apis/StoreApi.kt  |  25 ++
 .../org/openapitools/client/apis/UserApi.kt   |  37 ++
 .../client/infrastructure/ApiClient.kt        |  33 ++
 .../client/infrastructure/ByteArrayAdapter.kt |  12 +
 .../infrastructure/CollectionFormats.kt       |  56 +++
 .../client/infrastructure/LocalDateAdapter.kt |  19 +
 .../infrastructure/LocalDateTimeAdapter.kt    |  19 +
 .../client/infrastructure/Serializer.kt       |  18 +
 .../client/infrastructure/UUIDAdapter.kt      |  13 +
 .../openapitools/client/models/ApiResponse.kt |  33 ++
 .../openapitools/client/models/Category.kt    |  30 ++
 .../org/openapitools/client/models/Order.kt   |  55 +++
 .../org/openapitools/client/models/Pet.kt     |  57 +++
 .../org/openapitools/client/models/Tag.kt     |  30 ++
 .../org/openapitools/client/models/User.kt    |  49 +++
 53 files changed, 2424 insertions(+), 124 deletions(-)
 create mode 100755 bin/kotlin-client-retrofit2.sh
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/api.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/bodyParams.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/formParams.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/headerParams.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/ApiClient.kt.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/ByteArrayAdapter.kt.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/CollectionFormats.kt.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/DateAdapter.kt.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/LocalDateAdapter.kt.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/LocalDateTimeAdapter.kt.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/Serializer.kt.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/UUIDAdapter.kt.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/pathParams.mustache
 create mode 100644 modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/queryParams.mustache
 create mode 100644 samples/client/petstore/kotlin-retrofit2/.openapi-generator-ignore
 create mode 100644 samples/client/petstore/kotlin-retrofit2/.openapi-generator/VERSION
 create mode 100644 samples/client/petstore/kotlin-retrofit2/README.md
 create mode 100644 samples/client/petstore/kotlin-retrofit2/build.gradle
 create mode 100644 samples/client/petstore/kotlin-retrofit2/docs/ApiResponse.md
 create mode 100644 samples/client/petstore/kotlin-retrofit2/docs/Category.md
 create mode 100644 samples/client/petstore/kotlin-retrofit2/docs/Order.md
 create mode 100644 samples/client/petstore/kotlin-retrofit2/docs/Pet.md
 create mode 100644 samples/client/petstore/kotlin-retrofit2/docs/PetApi.md
 create mode 100644 samples/client/petstore/kotlin-retrofit2/docs/StoreApi.md
 create mode 100644 samples/client/petstore/kotlin-retrofit2/docs/Tag.md
 create mode 100644 samples/client/petstore/kotlin-retrofit2/docs/User.md
 create mode 100644 samples/client/petstore/kotlin-retrofit2/docs/UserApi.md
 create mode 100644 samples/client/petstore/kotlin-retrofit2/settings.gradle
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/PetApi.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/StoreApi.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/UserApi.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ByteArrayAdapter.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/CollectionFormats.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateAdapter.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateTimeAdapter.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/Serializer.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/UUIDAdapter.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/ApiResponse.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Category.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Order.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Pet.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Tag.kt
 create mode 100644 samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/User.kt

diff --git a/bin/kotlin-client-all.sh b/bin/kotlin-client-all.sh
index c27d1dcbcc2..f62755cf000 100755
--- a/bin/kotlin-client-all.sh
+++ b/bin/kotlin-client-all.sh
@@ -9,3 +9,4 @@
 ./bin/kotlin-client-string.sh
 ./bin/kotlin-client-threetenbp.sh
 ./bin/kotlin-client-nullable.sh
+./bin/kotlin-client-retrofit2.sh
diff --git a/bin/kotlin-client-retrofit2.sh b/bin/kotlin-client-retrofit2.sh
new file mode 100755
index 00000000000..52149c2e633
--- /dev/null
+++ b/bin/kotlin-client-retrofit2.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+
+SCRIPT="$0"
+echo "# START SCRIPT: $SCRIPT"
+
+while [ -h "$SCRIPT" ] ; do
+  ls=$(ls -ld "$SCRIPT")
+  link=$(expr "$ls" : '.*-> \(.*\)$')
+  if expr "$link" : '/.*' > /dev/null; then
+    SCRIPT="$link"
+  else
+    SCRIPT=$(dirname "$SCRIPT")/"$link"
+  fi
+done
+
+if [ ! -d "${APP_DIR}" ]; then
+  APP_DIR=$(dirname "$SCRIPT")/..
+  APP_DIR=$(cd "${APP_DIR}"; pwd)
+fi
+
+executable="./modules/openapi-generator-cli/target/openapi-generator-cli.jar"
+
+if [ ! -f "$executable" ]
+then
+  mvn -B clean package
+fi
+
+# if you've executed sbt assembly previously it will use that instead.
+export JAVA_OPTS="${JAVA_OPTS} -Xmx1024M -DloggerPath=conf/log4j.properties"
+ags="generate -t modules/openapi-generator/src/main/resources/kotlin-client -i modules/openapi-generator/src/test/resources/2_0/petstore.yaml -g kotlin --artifact-id kotlin-petstore-retrofit2 --library retrofit2 -o samples/client/petstore/kotlin-retrofit2 $@"
+
+java ${JAVA_OPTS} -jar ${executable} ${ags}
\ No newline at end of file
diff --git a/docs/generators/kotlin.md b/docs/generators/kotlin.md
index d64fd3964ff..86fbf23e5d0 100644
--- a/docs/generators/kotlin.md
+++ b/docs/generators/kotlin.md
@@ -18,4 +18,4 @@ sidebar_label: kotlin
 |modelMutable|Create mutable models| |false|
 |dateLibrary|Option. Date library to use|<dl><dt>**string**</dt><dd>String</dd><dt>**java8**</dt><dd>Java 8 native JSR310 (jvm only)</dd><dt>**threetenbp**</dt><dd>Threetenbp (jvm only)</dd><dl>|java8|
 |collectionType|Option. Collection type to use|<dl><dt>**array**</dt><dd>kotlin.Array</dd><dt>**list**</dt><dd>kotlin.collections.List</dd><dl>|array|
-|library|Library template (sub-template) to use|<dl><dt>**jvm-okhttp4**</dt><dd>[DEFAULT] Platform: Java Virtual Machine. HTTP client: OkHttp 4.2.0 (Android 5.0+ and Java 8+). JSON processing: Moshi 1.8.0.</dd><dt>**jvm-okhttp3**</dt><dd>Platform: Java Virtual Machine. HTTP client: OkHttp 3.12.4 (Android 2.3+ and Java 7+). JSON processing: Moshi 1.8.0.</dd><dt>**multiplatform**</dt><dd>Platform: Kotlin multiplatform. HTTP client: Ktor 1.2.4. JSON processing: Kotlinx Serialization: 0.12.0.</dd><dl>|jvm-okhttp4|
+|library|Library template (sub-template) to use|<dl><dt>**jvm-okhttp4**</dt><dd>[DEFAULT] Platform: Java Virtual Machine. HTTP client: OkHttp 4.2.0 (Android 5.0+ and Java 8+). JSON processing: Moshi 1.8.0.</dd><dt>**jvm-okhttp3**</dt><dd>Platform: Java Virtual Machine. HTTP client: OkHttp 3.12.4 (Android 2.3+ and Java 7+). JSON processing: Moshi 1.8.0.</dd><dt>**retrofit2**</dt><dd>Platform: Java Virtual Machine. HTTP client: Retrofit 2.6.2.</dd><dt>**multiplatform**</dt><dd>Platform: Kotlin multiplatform. HTTP client: Ktor 1.2.4. JSON processing: Kotlinx Serialization: 0.12.0.</dd><dl>|jvm-okhttp4|
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinClientCodegen.java
index 2f463f51a57..3d3e7fbe748 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinClientCodegen.java
@@ -29,6 +29,7 @@ import org.openapitools.codegen.SupportingFile;
 import java.io.File;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -38,6 +39,7 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
     protected static final String JVM = "jvm";
     protected static final String JVM_OKHTTP4 = "jvm-okhttp4";
     protected static final String JVM_OKHTTP3 = "jvm-okhttp3";
+    protected static final String RETROFIT2 = "retrofit2";
     protected static final String MULTIPLATFORM = "multiplatform";
 
     public static final String DATE_LIBRARY = "dateLibrary";
@@ -112,6 +114,7 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
 
         supportedLibraries.put(JVM_OKHTTP4, "[DEFAULT] Platform: Java Virtual Machine. HTTP client: OkHttp 4.2.0 (Android 5.0+ and Java 8+). JSON processing: Moshi 1.8.0.");
         supportedLibraries.put(JVM_OKHTTP3, "Platform: Java Virtual Machine. HTTP client: OkHttp 3.12.4 (Android 2.3+ and Java 7+). JSON processing: Moshi 1.8.0.");
+        supportedLibraries.put(RETROFIT2, "Platform: Java Virtual Machine. HTTP client: Retrofit 2.6.2.");
         supportedLibraries.put(MULTIPLATFORM, "Platform: Kotlin multiplatform. HTTP client: Ktor 1.2.4. JSON processing: Kotlinx Serialization: 0.12.0.");
 
         CliOption libraryOption = new CliOption(CodegenConstants.LIBRARY, "Library template (sub-template) to use");
@@ -157,115 +160,24 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
             setDateLibrary(additionalProperties.get(DATE_LIBRARY).toString());
         }
 
-        // common (jvm/multiplatform) supporting files
-        supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
-        supportingFiles.add(new SupportingFile("build.gradle.mustache", "", "build.gradle"));
-        supportingFiles.add(new SupportingFile("settings.gradle.mustache", "", "settings.gradle"));
-        supportingFiles.add(new SupportingFile("infrastructure/ApiClient.kt.mustache", infrastructureFolder, "ApiClient.kt"));
-        supportingFiles.add(new SupportingFile("infrastructure/ApiAbstractions.kt.mustache", infrastructureFolder, "ApiAbstractions.kt"));
-        supportingFiles.add(new SupportingFile("infrastructure/RequestConfig.kt.mustache", infrastructureFolder, "RequestConfig.kt"));
-        supportingFiles.add(new SupportingFile("infrastructure/RequestMethod.kt.mustache", infrastructureFolder, "RequestMethod.kt"));
+        commonSupportingFiles();
 
-        if (isJVMLibrary()) {
-            additionalProperties.put(JVM, true);
-
-            if (JVM_OKHTTP4.equals(getLibrary())) {
-                additionalProperties.put(JVM_OKHTTP4, true);
-            } else if (JVM_OKHTTP3.equals(getLibrary())) {
-                additionalProperties.put(JVM_OKHTTP3, true);
-            }
-
-            supportedLibraries.put(JVM, "A workaround to use the same template folder for both 'jvm-okhttp3' and 'jvm-okhttp4'.");
-            setLibrary(JVM);
-
-            // jvm specific supporting files
-            supportingFiles.add(new SupportingFile("infrastructure/ApplicationDelegates.kt.mustache", infrastructureFolder, "ApplicationDelegates.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/Errors.kt.mustache", infrastructureFolder, "Errors.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/ResponseExtensions.kt.mustache", infrastructureFolder, "ResponseExtensions.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/Serializer.kt.mustache", infrastructureFolder, "Serializer.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/ApiInfrastructureResponse.kt.mustache", infrastructureFolder, "ApiInfrastructureResponse.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/ByteArrayAdapter.kt.mustache", infrastructureFolder, "ByteArrayAdapter.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/LocalDateAdapter.kt.mustache", infrastructureFolder, "LocalDateAdapter.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/LocalDateTimeAdapter.kt.mustache", infrastructureFolder, "LocalDateTimeAdapter.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/UUIDAdapter.kt.mustache", infrastructureFolder, "UUIDAdapter.kt"));
-            if (getSerializationLibrary() == SERIALIZATION_LIBRARY_TYPE.gson) {
-                supportingFiles.add(new SupportingFile("infrastructure/DateAdapter.kt.mustache", infrastructureFolder,
-                        "DateAdapter.kt"));
-            }
-
-        } else if (MULTIPLATFORM.equals(getLibrary())) {
-            additionalProperties.put(MULTIPLATFORM, true);
-            setDateLibrary(DateLibrary.STRING.value);
-
-            // multiplatform default includes
-            defaultIncludes.add("io.ktor.client.request.forms.InputProvider");
-            defaultIncludes.add(packageName + ".infrastructure.Base64ByteArray");
-            defaultIncludes.add(packageName + ".infrastructure.OctetByteArray");
-
-            // multiplatform type mapping
-            typeMapping.put("number", "kotlin.Double");
-            typeMapping.put("file", "OctetByteArray");
-            typeMapping.put("binary", "OctetByteArray");
-            typeMapping.put("ByteArray", "Base64ByteArray");
-            typeMapping.put("object", "kotlin.String");  // kotlin.Any not serializable
-
-            // multiplatform import mapping
-            importMapping.put("BigDecimal", "kotlin.Double");
-            importMapping.put("UUID", "kotlin.String");
-            importMapping.put("URI", "kotlin.String");
-            importMapping.put("InputProvider", "io.ktor.client.request.forms.InputProvider");
-            importMapping.put("File", packageName + ".infrastructure.OctetByteArray");
-            importMapping.put("Timestamp", "kotlin.String");
-            importMapping.put("LocalDateTime", "kotlin.String");
-            importMapping.put("LocalDate", "kotlin.String");
-            importMapping.put("LocalTime", "kotlin.String");
-            importMapping.put("Base64ByteArray", packageName + ".infrastructure.Base64ByteArray");
-            importMapping.put("OctetByteArray", packageName + ".infrastructure.OctetByteArray");
-
-            // multiplatform specific supporting files
-            supportingFiles.add(new SupportingFile("infrastructure/Base64ByteArray.kt.mustache", infrastructureFolder, "Base64ByteArray.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/Bytes.kt.mustache", infrastructureFolder, "Bytes.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/HttpResponse.kt.mustache", infrastructureFolder, "HttpResponse.kt"));
-            supportingFiles.add(new SupportingFile("infrastructure/OctetByteArray.kt.mustache", infrastructureFolder, "OctetByteArray.kt"));
-
-            // multiplatform specific auth
-            final String authFolder = (sourceFolder + File.separator + packageName + File.separator + "auth").replace(".", "/");
-            supportingFiles.add(new SupportingFile("auth/ApiKeyAuth.kt.mustache", authFolder, "ApiKeyAuth.kt"));
-            supportingFiles.add(new SupportingFile("auth/Authentication.kt.mustache", authFolder, "Authentication.kt"));
-            supportingFiles.add(new SupportingFile("auth/HttpBasicAuth.kt.mustache", authFolder, "HttpBasicAuth.kt"));
-            supportingFiles.add(new SupportingFile("auth/HttpBearerAuth.kt.mustache", authFolder, "HttpBearerAuth.kt"));
-            supportingFiles.add(new SupportingFile("auth/OAuth.kt.mustache", authFolder, "OAuth.kt"));
-
-            // multiplatform specific testing files
-            supportingFiles.add(new SupportingFile("commonTest/Coroutine.kt.mustache", "src/commonTest/kotlin/util", "Coroutine.kt"));
-            supportingFiles.add(new SupportingFile("iosTest/Coroutine.kt.mustache", "src/iosTest/kotlin/util", "Coroutine.kt"));
-            supportingFiles.add(new SupportingFile("jsTest/Coroutine.kt.mustache", "src/jsTest/kotlin/util", "Coroutine.kt"));
-            supportingFiles.add(new SupportingFile("jvmTest/Coroutine.kt.mustache", "src/jvmTest/kotlin/util", "Coroutine.kt"));
-
-            // gradle wrapper supporting files
-            supportingFiles.add(new SupportingFile("gradlew.mustache", "", "gradlew"));
-            supportingFiles.add(new SupportingFile("gradlew.bat.mustache", "", "gradlew.bat"));
-            supportingFiles.add(new SupportingFile("gradle-wrapper.properties.mustache", "gradle.wrapper".replace(".", File.separator), "gradle-wrapper.properties"));
-            supportingFiles.add(new SupportingFile("gradle-wrapper.jar", "gradle.wrapper".replace(".", File.separator), "gradle-wrapper.jar"));
+        switch (getLibrary()) {
+            case JVM_OKHTTP3:
+            case JVM_OKHTTP4:
+                processJVMLibrary(infrastructureFolder);
+                break;
+            case RETROFIT2:
+                processRetrofit2Library(infrastructureFolder);
+                break;
+            case MULTIPLATFORM:
+                processMultiplatformLibrary(infrastructureFolder);
+                break;
+            default:
+                break;
         }
 
-        // date library processing
-        if (DateLibrary.THREETENBP.value.equals(dateLibrary)) {
-            additionalProperties.put(DateLibrary.THREETENBP.value, true);
-            typeMapping.put("date", "LocalDate");
-            typeMapping.put("DateTime", "LocalDateTime");
-            importMapping.put("LocalDate", "org.threeten.bp.LocalDate");
-            importMapping.put("LocalDateTime", "org.threeten.bp.LocalDateTime");
-            defaultIncludes.add("org.threeten.bp.LocalDate");
-            defaultIncludes.add("org.threeten.bp.LocalDateTime");
-        } else if (DateLibrary.STRING.value.equals(dateLibrary)) {
-            typeMapping.put("date-time", "kotlin.String");
-            typeMapping.put("date", "kotlin.String");
-            typeMapping.put("Date", "kotlin.String");
-            typeMapping.put("DateTime", "kotlin.String");
-        } else if (DateLibrary.JAVA8.value.equals(dateLibrary)) {
-            additionalProperties.put(DateLibrary.JAVA8.value, true);
-        }
+        processDateLibrary();
 
         if (additionalProperties.containsKey(COLLECTION_TYPE)) {
             setCollectionType(additionalProperties.get(COLLECTION_TYPE).toString());
@@ -276,11 +188,157 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
             typeMapping.put("list", "kotlin.collections.List");
             additionalProperties.put("isList", true);
         }
-
     }
 
-    private boolean isJVMLibrary() {
-        return getLibrary() != null && (getLibrary().contains(JVM_OKHTTP4) || getLibrary().contains(JVM_OKHTTP3));
+    private void processDateLibrary() {
+        DateLibrary dateLibraryEnum = DateLibrary.valueOf(dateLibrary.toUpperCase(Locale.ROOT));
+        switch (dateLibraryEnum) {
+            case THREETENBP:
+                processThreeTeBpDate();
+                break;
+            case STRING:
+                processStringDate();
+                break;
+            case JAVA8:
+                processJava8Date();
+                break;
+            default:
+                break;
+        }
+    }
+
+    private void processThreeTeBpDate() {
+        additionalProperties.put(DateLibrary.THREETENBP.value, true);
+        typeMapping.put("date", "LocalDate");
+        typeMapping.put("DateTime", "LocalDateTime");
+        importMapping.put("LocalDate", "org.threeten.bp.LocalDate");
+        importMapping.put("LocalDateTime", "org.threeten.bp.LocalDateTime");
+        defaultIncludes.add("org.threeten.bp.LocalDate");
+        defaultIncludes.add("org.threeten.bp.LocalDateTime");
+    }
+
+    private void processStringDate() {
+        typeMapping.put("date-time", "kotlin.String");
+        typeMapping.put("date", "kotlin.String");
+        typeMapping.put("Date", "kotlin.String");
+        typeMapping.put("DateTime", "kotlin.String");
+    }
+
+    private void processJava8Date() {
+        additionalProperties.put(DateLibrary.JAVA8.value, true);
+    }
+
+    private void processRetrofit2Library(String infrastructureFolder) {
+        additionalProperties.put(RETROFIT2, true);
+        supportingFiles.add(new SupportingFile("infrastructure/ApiClient.kt.mustache", infrastructureFolder, "ApiClient.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/CollectionFormats.kt.mustache", infrastructureFolder, "CollectionFormats.kt"));
+        addSupportingSerializerAdapters(infrastructureFolder);
+    }
+
+    private void addSupportingSerializerAdapters(final String infrastructureFolder) {
+        supportingFiles.add(new SupportingFile("infrastructure/Serializer.kt.mustache", infrastructureFolder, "Serializer.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/ByteArrayAdapter.kt.mustache", infrastructureFolder, "ByteArrayAdapter.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/LocalDateAdapter.kt.mustache", infrastructureFolder, "LocalDateAdapter.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/LocalDateTimeAdapter.kt.mustache", infrastructureFolder, "LocalDateTimeAdapter.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/UUIDAdapter.kt.mustache", infrastructureFolder, "UUIDAdapter.kt"));
+
+        if (getSerializationLibrary() == SERIALIZATION_LIBRARY_TYPE.gson) {
+            supportingFiles.add(new SupportingFile("infrastructure/DateAdapter.kt.mustache", infrastructureFolder,
+                    "DateAdapter.kt"));
+        }
+    }
+
+    private void processJVMLibrary(final String infrastructureFolder) {
+        commonJvmMultiplatformSupportingFiles(infrastructureFolder);
+        addSupportingSerializerAdapters(infrastructureFolder);
+
+        additionalProperties.put(JVM, true);
+
+        if (JVM_OKHTTP4.equals(getLibrary())) {
+            additionalProperties.put(JVM_OKHTTP4, true);
+        } else if (JVM_OKHTTP3.equals(getLibrary())) {
+            additionalProperties.put(JVM_OKHTTP3, true);
+        }
+
+        supportedLibraries.put(JVM, "A workaround to use the same template folder for both 'jvm-okhttp3' and 'jvm-okhttp4'.");
+        setLibrary(JVM);
+
+        // jvm specific supporting files
+        supportingFiles.add(new SupportingFile("infrastructure/ApplicationDelegates.kt.mustache", infrastructureFolder, "ApplicationDelegates.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/Errors.kt.mustache", infrastructureFolder, "Errors.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/ResponseExtensions.kt.mustache", infrastructureFolder, "ResponseExtensions.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/ApiInfrastructureResponse.kt.mustache", infrastructureFolder, "ApiInfrastructureResponse.kt"));
+    }
+
+    private void processMultiplatformLibrary(final String infrastructureFolder) {
+        commonJvmMultiplatformSupportingFiles(infrastructureFolder);
+        additionalProperties.put(MULTIPLATFORM, true);
+        setDateLibrary(DateLibrary.STRING.value);
+
+        // multiplatform default includes
+        defaultIncludes.add("io.ktor.client.request.forms.InputProvider");
+        defaultIncludes.add(packageName + ".infrastructure.Base64ByteArray");
+        defaultIncludes.add(packageName + ".infrastructure.OctetByteArray");
+
+        // multiplatform type mapping
+        typeMapping.put("number", "kotlin.Double");
+        typeMapping.put("file", "OctetByteArray");
+        typeMapping.put("binary", "OctetByteArray");
+        typeMapping.put("ByteArray", "Base64ByteArray");
+        typeMapping.put("object", "kotlin.String");  // kotlin.Any not serializable
+
+        // multiplatform import mapping
+        importMapping.put("BigDecimal", "kotlin.Double");
+        importMapping.put("UUID", "kotlin.String");
+        importMapping.put("URI", "kotlin.String");
+        importMapping.put("InputProvider", "io.ktor.client.request.forms.InputProvider");
+        importMapping.put("File", packageName + ".infrastructure.OctetByteArray");
+        importMapping.put("Timestamp", "kotlin.String");
+        importMapping.put("LocalDateTime", "kotlin.String");
+        importMapping.put("LocalDate", "kotlin.String");
+        importMapping.put("LocalTime", "kotlin.String");
+        importMapping.put("Base64ByteArray", packageName + ".infrastructure.Base64ByteArray");
+        importMapping.put("OctetByteArray", packageName + ".infrastructure.OctetByteArray");
+
+        // multiplatform specific supporting files
+        supportingFiles.add(new SupportingFile("infrastructure/Base64ByteArray.kt.mustache", infrastructureFolder, "Base64ByteArray.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/Bytes.kt.mustache", infrastructureFolder, "Bytes.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/HttpResponse.kt.mustache", infrastructureFolder, "HttpResponse.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/OctetByteArray.kt.mustache", infrastructureFolder, "OctetByteArray.kt"));
+
+        // multiplatform specific auth
+        final String authFolder = (sourceFolder + File.separator + packageName + File.separator + "auth").replace(".", "/");
+        supportingFiles.add(new SupportingFile("auth/ApiKeyAuth.kt.mustache", authFolder, "ApiKeyAuth.kt"));
+        supportingFiles.add(new SupportingFile("auth/Authentication.kt.mustache", authFolder, "Authentication.kt"));
+        supportingFiles.add(new SupportingFile("auth/HttpBasicAuth.kt.mustache", authFolder, "HttpBasicAuth.kt"));
+        supportingFiles.add(new SupportingFile("auth/HttpBearerAuth.kt.mustache", authFolder, "HttpBearerAuth.kt"));
+        supportingFiles.add(new SupportingFile("auth/OAuth.kt.mustache", authFolder, "OAuth.kt"));
+
+        // multiplatform specific testing files
+        supportingFiles.add(new SupportingFile("commonTest/Coroutine.kt.mustache", "src/commonTest/kotlin/util", "Coroutine.kt"));
+        supportingFiles.add(new SupportingFile("iosTest/Coroutine.kt.mustache", "src/iosTest/kotlin/util", "Coroutine.kt"));
+        supportingFiles.add(new SupportingFile("jsTest/Coroutine.kt.mustache", "src/jsTest/kotlin/util", "Coroutine.kt"));
+        supportingFiles.add(new SupportingFile("jvmTest/Coroutine.kt.mustache", "src/jvmTest/kotlin/util", "Coroutine.kt"));
+
+        // gradle wrapper supporting files
+        supportingFiles.add(new SupportingFile("gradlew.mustache", "", "gradlew"));
+        supportingFiles.add(new SupportingFile("gradlew.bat.mustache", "", "gradlew.bat"));
+        supportingFiles.add(new SupportingFile("gradle-wrapper.properties.mustache", "gradle.wrapper".replace(".", File.separator), "gradle-wrapper.properties"));
+        supportingFiles.add(new SupportingFile("gradle-wrapper.jar", "gradle.wrapper".replace(".", File.separator), "gradle-wrapper.jar"));
+    }
+
+
+    private void commonJvmMultiplatformSupportingFiles(String infrastructureFolder) {
+        supportingFiles.add(new SupportingFile("infrastructure/ApiClient.kt.mustache", infrastructureFolder, "ApiClient.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/ApiAbstractions.kt.mustache", infrastructureFolder, "ApiAbstractions.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/RequestConfig.kt.mustache", infrastructureFolder, "RequestConfig.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/RequestMethod.kt.mustache", infrastructureFolder, "RequestMethod.kt"));
+    }
+
+    private void commonSupportingFiles() {
+        supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
+        supportingFiles.add(new SupportingFile("build.gradle.mustache", "", "build.gradle"));
+        supportingFiles.add(new SupportingFile("settings.gradle.mustache", "", "settings.gradle"));
     }
 
     @Override
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/build.gradle.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/build.gradle.mustache
index 6cafc6f241f..c8d924f81cd 100644
--- a/modules/openapi-generator/src/main/resources/kotlin-client/build.gradle.mustache
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/build.gradle.mustache
@@ -8,6 +8,9 @@ wrapper {
 
 buildscript {
     ext.kotlin_version = '1.3.61'
+    {{#retrofit2}}
+    ext.retrofitVersion = '2.6.2'
+    {{/retrofit2}}
 
     repositories {
         mavenCentral()
@@ -38,10 +41,10 @@ dependencies {
     compile "com.squareup.moshi:moshi-kotlin:1.9.2"
     {{/moshiCodeGen}}
     compile "com.squareup.moshi:moshi-adapters:1.9.2"
-    {{#moshiCodeGen}} 
+    {{#moshiCodeGen}}
     compile "com.squareup.moshi:moshi:1.9.2"
     kapt "com.squareup.moshi:moshi-kotlin-codegen:1.9.2"
-    {{/moshiCodeGen}} 
+    {{/moshiCodeGen}}
     {{/moshi}}
     {{#gson}}
     compile "com.google.code.gson:gson:2.8.6"
@@ -55,5 +58,15 @@ dependencies {
     {{#threetenbp}}
     compile "org.threeten:threetenbp:1.4.0"
     {{/threetenbp}}
+    {{#retrofit2}}
+    compile "com.squareup.retrofit2:retrofit:$retrofitVersion"
+    {{#gson}}
+    compile "com.squareup.retrofit2:converter-gson:$retrofitVersion"
+    {{/gson}}
+    {{#moshi}}
+    compile "com.squareup.retrofit2:converter-moshi:$retrofitVersion"
+    {{/moshi}}
+    compile "com.squareup.retrofit2:converter-scalars:$retrofitVersion"
+    {{/retrofit2}}
     testCompile "io.kotlintest:kotlintest-runner-junit5:3.1.0"
 }
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/data_class.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/data_class.mustache
index 5cd71c1559c..df8e22b9f84 100644
--- a/modules/openapi-generator/src/main/resources/kotlin-client/data_class.mustache
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/data_class.mustache
@@ -1,4 +1,4 @@
-{{#jvm}}
+{{^multiplatform}}
 {{#gson}}
 import com.google.gson.annotations.SerializedName
 {{/gson}}
@@ -13,7 +13,7 @@ import android.os.Parcelable
 import kotlinx.android.parcel.Parcelize
 
 {{/parcelizeModels}}
-{{/jvm}}
+{{/multiplatform}}
 {{#multiplatform}}
 import kotlinx.serialization.*
 import kotlinx.serialization.internal.CommonEnumSerializer
@@ -59,14 +59,14 @@ import java.io.Serializable
     {{#nonPublicApi}}internal {{/nonPublicApi}}enum class {{{nameInCamelCase}}}(val value: {{#isListContainer}}{{{ nestedType }}}{{/isListContainer}}{{^isListContainer}}{{{dataType}}}{{/isListContainer}}){
     {{#allowableValues}}
     {{#enumVars}}
-        {{#jvm}}
+        {{^multiplatform}}
         {{#moshi}}
         @Json(name = {{{value}}}) {{&name}}({{{value}}}){{^-last}},{{/-last}}{{#-last}};{{/-last}}
         {{/moshi}}
         {{#gson}}
         @SerializedName(value={{{value}}})  {{&name}}({{{value}}}){{^-last}},{{/-last}}{{#-last}};{{/-last}}
         {{/gson}}
-        {{/jvm}}
+        {{/multiplatform}}
         {{#multiplatform}}
         {{&name}}({{{value}}}){{^-last}},{{/-last}}{{#-last}};{{/-last}}
         {{/multiplatform}}
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/data_class_opt_var.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/data_class_opt_var.mustache
index ff0fc3a4ce5..3a8d2871db6 100644
--- a/modules/openapi-generator/src/main/resources/kotlin-client/data_class_opt_var.mustache
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/data_class_opt_var.mustache
@@ -1,12 +1,12 @@
 {{#description}}
     /* {{{description}}} */
 {{/description}}
-    {{#jvm}}
+    {{^multiplatform}}
     {{#moshi}}
     @Json(name = "{{{vendorExtensions.x-base-name-literal}}}")
     {{/moshi}}
     {{#gson}}
     @SerializedName("{{{vendorExtensions.x-base-name-literal}}}")
     {{/gson}}
-    {{/jvm}}
+    {{/multiplatform}}
     {{#multiplatform}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}") {{/multiplatform}}{{>modelMutable}} {{{name}}}: {{#isEnum}}{{#isListContainer}}{{#isList}}kotlin.collections.List{{/isList}}{{^isList}}kotlin.Array{{/isList}}<{{classname}}.{{{nameInCamelCase}}}>{{/isListContainer}}{{^isListContainer}}{{classname}}.{{{nameInCamelCase}}}{{/isListContainer}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}? = {{#defaultvalue}}{{defaultvalue}}{{/defaultvalue}}{{^defaultvalue}}null{{/defaultvalue}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/data_class_req_var.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/data_class_req_var.mustache
index c7a068e7ca3..ca645e26c85 100644
--- a/modules/openapi-generator/src/main/resources/kotlin-client/data_class_req_var.mustache
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/data_class_req_var.mustache
@@ -1,12 +1,12 @@
 {{#description}}
     /* {{{description}}} */
 {{/description}}
-    {{#jvm}}
+    {{^multiplatform}}
     {{#moshi}}
     @Json(name = "{{{vendorExtensions.x-base-name-literal}}}")
     {{/moshi}}
     {{#gson}}
     @SerializedName("{{{vendorExtensions.x-base-name-literal}}}")
     {{/gson}}
-    {{/jvm}}
+    {{/multiplatform}}
     {{#multiplatform}}@SerialName(value = "{{{vendorExtensions.x-base-name-literal}}}") @Required {{/multiplatform}}{{>modelMutable}} {{{name}}}: {{#isEnum}}{{#isListContainer}}{{#isList}}kotlin.collections.List{{/isList}}{{^isList}}kotlin.Array{{/isList}}<{{classname}}.{{{nameInCamelCase}}}>{{/isListContainer}}{{^isListContainer}}{{classname}}.{{{nameInCamelCase}}}{{/isListContainer}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}{{#isNullable}}?{{/isNullable}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/enum_class.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/enum_class.mustache
index 9c848451846..73113186c51 100644
--- a/modules/openapi-generator/src/main/resources/kotlin-client/enum_class.mustache
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/enum_class.mustache
@@ -1,11 +1,11 @@
-{{#jvm}}
+{{^multiplatform}}
 {{#gson}}
 import com.google.gson.annotations.SerializedName
 {{/gson}}
 {{#moshi}}
 import com.squareup.moshi.Json
 {{/moshi}}
-{{/jvm}}
+{{/multiplatform}}
 {{#multiplatform}}
 import kotlinx.serialization.*
 import kotlinx.serialization.internal.CommonEnumSerializer
@@ -19,14 +19,14 @@ import kotlinx.serialization.internal.CommonEnumSerializer
 {{#nonPublicApi}}internal {{/nonPublicApi}}enum class {{classname}}(val value: {{{dataType}}}){
 
 {{#allowableValues}}{{#enumVars}}
-    {{#jvm}}
+    {{^multiplatform}}
     {{#moshi}}
     @Json(name = {{^isString}}"{{/isString}}{{{value}}}{{^isString}}"{{/isString}})
     {{/moshi}}
     {{#gson}}
     @SerializedName(value = {{^isString}}"{{/isString}}{{{value}}}{{^isString}}"{{/isString}})
     {{/gson}}
-    {{/jvm}}
+    {{/multiplatform}}
     {{#isListContainer}}
     {{#isList}}
     {{&name}}(listOf({{{value}}})){{^-last}},{{/-last}}{{#-last}};{{/-last}}
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/api.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/api.mustache
new file mode 100644
index 00000000000..b9e20312aae
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/api.mustache
@@ -0,0 +1,38 @@
+package {{apiPackage}}
+
+import {{packageName}}.infrastructure.CollectionFormats.*
+import retrofit2.http.*
+import retrofit2.Call
+import okhttp3.RequestBody
+import okhttp3.ResponseBody
+import okhttp3.MultipartBody
+
+{{#imports}}import {{import}}
+{{/imports}}
+
+{{#operations}}
+interface {{classname}} {
+    {{#operation}}
+    {{#isDeprecated}}
+    @Deprecated("This api was deprecated")
+    {{/isDeprecated}}
+    {{#formParams}}
+    {{#-first}}
+    {{#isMultipart}}@Multipart{{/isMultipart}}{{^isMultipart}}@FormUrlEncoded{{/isMultipart}}
+    {{/-first}}
+    {{/formParams}}
+    {{^formParams}}
+    {{#prioritizedContentTypes}}
+    {{#-first}}
+    @Headers({
+        "Content-Type:{{{mediaType}}}"
+    })
+    {{/-first}}
+    {{/prioritizedContentTypes}}
+    {{/formParams}}
+    @{{httpMethod}}("{{{path}}}")
+    fun {{operationId}}({{^allParams}}){{/allParams}}{{#allParams}}{{>libraries/retrofit2/queryParams}}{{>libraries/retrofit2/pathParams}}{{>libraries/retrofit2/headerParams}}{{>libraries/retrofit2/bodyParams}}{{>libraries/retrofit2/formParams}}{{#hasMore}}, {{/hasMore}}{{^hasMore}}){{/hasMore}}{{/allParams}}: Call<{{#isResponseFile}}ResponseBody{{/isResponseFile}}{{^isResponseFile}}{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Unit{{/returnType}}{{/isResponseFile}}>
+
+    {{/operation}}
+}
+{{/operations}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/bodyParams.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/bodyParams.mustache
new file mode 100644
index 00000000000..079fbb1169b
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/bodyParams.mustache
@@ -0,0 +1 @@
+{{#isBodyParam}}@Body {{paramName}}: {{{dataType}}}{{/isBodyParam}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/formParams.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/formParams.mustache
new file mode 100644
index 00000000000..5a7f687061d
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/formParams.mustache
@@ -0,0 +1 @@
+{{#isFormParam}}{{^isFile}}{{#isMultipart}}@Part{{/isMultipart}}{{^isMultipart}}@Field{{/isMultipart}}("{{baseName}}") {{paramName}}: {{{dataType}}}{{/isFile}}{{#isFile}}{{#isMultipart}}@Part{{/isMultipart}}{{^isMultipart}}@Field("{{baseName}}"){{/isMultipart}} {{paramName}}: MultipartBody.Part {{/isFile}}{{/isFormParam}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/headerParams.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/headerParams.mustache
new file mode 100644
index 00000000000..2b26c446678
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/headerParams.mustache
@@ -0,0 +1 @@
+{{#isHeaderParam}}@Header("{{baseName}}") {{paramName}}: {{{dataType}}}{{/isHeaderParam}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/ApiClient.kt.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/ApiClient.kt.mustache
new file mode 100644
index 00000000000..eab46f77ad4
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/ApiClient.kt.mustache
@@ -0,0 +1,43 @@
+package {{packageName}}.infrastructure
+
+import okhttp3.OkHttpClient
+import retrofit2.Retrofit
+import retrofit2.converter.scalars.ScalarsConverterFactory
+{{#gson}}
+import retrofit2.converter.gson.GsonConverterFactory
+{{/gson}}
+{{#moshi}}
+import retrofit2.converter.moshi.MoshiConverterFactory
+{{/moshi}}
+
+{{#nonPublicApi}}internal {{/nonPublicApi}}class ApiClient(
+    private var baseUrl: String = "{{{basePath}}}",
+    private var okHttpClient: OkHttpClient
+) {
+    init {
+        normalizeBaseUrl()
+    }
+
+    val retrofitBuilder: Retrofit.Builder by lazy {
+
+        Retrofit.Builder()
+        .baseUrl(baseUrl)
+        .addConverterFactory(ScalarsConverterFactory.create())
+        {{#gson}}
+        .addConverterFactory(GsonConverterFactory.create(Serializer.gson))
+        {{/gson}}
+        {{#moshi}}
+        .addConverterFactory(MoshiConverterFactory.create(Serializer.moshi))
+        {{/moshi}}
+    }
+
+    fun <S> createService(serviceClass: Class<S>): S {
+        return retrofitBuilder.client(okHttpClient).build().create(serviceClass)
+    }
+
+    private fun normalizeBaseUrl() {
+        if (!baseUrl.endsWith("/")) {
+            baseUrl += "/"
+        }
+    }
+}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/ByteArrayAdapter.kt.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/ByteArrayAdapter.kt.mustache
new file mode 100644
index 00000000000..9f56848226c
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/ByteArrayAdapter.kt.mustache
@@ -0,0 +1,50 @@
+package {{packageName}}.infrastructure
+
+{{#moshi}}
+import com.squareup.moshi.FromJson
+import com.squareup.moshi.ToJson
+{{/moshi}}
+{{#gson}}
+import com.google.gson.TypeAdapter
+import com.google.gson.stream.JsonReader
+import com.google.gson.stream.JsonWriter
+import com.google.gson.stream.JsonToken.NULL
+import java.io.IOException
+{{/gson}}
+
+{{#moshi}}
+{{#nonPublicApi}}internal {{/nonPublicApi}}class ByteArrayAdapter {
+    @ToJson
+    fun toJson(data: ByteArray): String = String(data)
+
+    @FromJson
+    fun fromJson(data: String): ByteArray = data.toByteArray()
+}
+{{/moshi}}
+{{#gson}}
+{{#nonPublicApi}}internal {{/nonPublicApi}}class ByteArrayAdapter : TypeAdapter<ByteArray>() {
+    @Throws(IOException::class)
+    override fun write(out: JsonWriter?, value: ByteArray?) {
+        if (value == null) {
+            out?.nullValue()
+        } else {
+            out?.value(String(value))
+        }
+    }
+
+    @Throws(IOException::class)
+    override fun read(out: JsonReader?): ByteArray? {
+        out ?: return null
+
+        when (out.peek()) {
+            NULL -> {
+                out.nextNull()
+                return null
+            }
+            else -> {
+                return out.nextString().toByteArray()
+            }
+        }
+    }
+}
+{{/gson}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/CollectionFormats.kt.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/CollectionFormats.kt.mustache
new file mode 100644
index 00000000000..659f2df4851
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/CollectionFormats.kt.mustache
@@ -0,0 +1,56 @@
+package {{packageName}}.infrastructure
+
+class CollectionFormats {
+
+    open class CSVParams {
+
+        var params: List<String>
+
+        constructor(params: List<String>) {
+            this.params = params
+        }
+
+        constructor(vararg params: String) {
+            this.params = listOf(*params)
+        }
+
+        override fun toString(): String {
+            return params.joinToString(",")
+        }
+    }
+
+    open class SSVParams : CSVParams {
+
+        constructor(params: List<String>) : super(params)
+
+        constructor(vararg params: String) : super(*params)
+
+        override fun toString(): String {
+            return params.joinToString(" ")
+        }
+    }
+
+    class TSVParams : CSVParams {
+
+        constructor(params: List<String>) : super(params)
+
+        constructor(vararg params: String) : super(*params)
+
+        override fun toString(): String {
+            return params.joinToString("\t")
+        }
+    }
+
+    class PIPESParams : CSVParams {
+
+        constructor(params: List<String>) : super(params)
+
+        constructor(vararg params: String) : super(*params)
+
+        override fun toString(): String {
+            return params.joinToString("|")
+        }
+    }
+
+    class SPACEParams : SSVParams()
+}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/DateAdapter.kt.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/DateAdapter.kt.mustache
new file mode 100644
index 00000000000..e24c32c87aa
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/DateAdapter.kt.mustache
@@ -0,0 +1,37 @@
+package {{packageName}}.infrastructure
+
+import com.google.gson.TypeAdapter
+import com.google.gson.stream.JsonReader
+import com.google.gson.stream.JsonWriter
+import com.google.gson.stream.JsonToken.NULL
+import java.io.IOException
+import java.text.DateFormat
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+
+{{#nonPublicApi}}internal {{/nonPublicApi}}class DateAdapter(val formatter: DateFormat = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ", Locale.getDefault())) : TypeAdapter<Date>() {
+    @Throws(IOException::class)
+    override fun write(out: JsonWriter?, value: Date?) {
+        if (value == null) {
+            out?.nullValue()
+        } else {
+            out?.value(formatter.format(value))
+        }
+    }
+
+    @Throws(IOException::class)
+    override fun read(out: JsonReader?): Date? {
+        out ?: return null
+
+        when (out.peek()) {
+            NULL -> {
+                out.nextNull()
+                return null
+            }
+            else -> {
+                return formatter.parse(out.nextString())
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/LocalDateAdapter.kt.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/LocalDateAdapter.kt.mustache
new file mode 100644
index 00000000000..152266a5964
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/LocalDateAdapter.kt.mustache
@@ -0,0 +1,63 @@
+package {{packageName}}.infrastructure
+
+{{#moshi}}
+import com.squareup.moshi.FromJson
+import com.squareup.moshi.ToJson
+{{/moshi}}
+{{#gson}}
+import com.google.gson.TypeAdapter
+import com.google.gson.stream.JsonReader
+import com.google.gson.stream.JsonWriter
+import com.google.gson.stream.JsonToken.NULL
+import java.io.IOException
+{{/gson}}
+{{^threetenbp}}
+import java.time.LocalDate
+import java.time.format.DateTimeFormatter
+{{/threetenbp}}
+{{#threetenbp}}
+import org.threeten.bp.LocalDate
+import org.threeten.bp.format.DateTimeFormatter
+{{/threetenbp}}
+
+{{#moshi}}
+{{#nonPublicApi}}internal {{/nonPublicApi}}class LocalDateAdapter {
+    @ToJson
+    fun toJson(value: LocalDate): String {
+        return DateTimeFormatter.ISO_LOCAL_DATE.format(value)
+    }
+
+    @FromJson
+    fun fromJson(value: String): LocalDate {
+        return LocalDate.parse(value, DateTimeFormatter.ISO_LOCAL_DATE)
+    }
+
+}
+{{/moshi}}
+{{#gson}}
+{{#nonPublicApi}}internal {{/nonPublicApi}}class LocalDateAdapter(private val formatter: DateTimeFormatter = DateTimeFormatter.ISO_LOCAL_DATE) : TypeAdapter<LocalDate>() {
+    @Throws(IOException::class)
+    override fun write(out: JsonWriter?, value: LocalDate?) {
+        if (value == null) {
+            out?.nullValue()
+        } else {
+            out?.value(formatter.format(value))
+        }
+    }
+
+    @Throws(IOException::class)
+    override fun read(out: JsonReader?): LocalDate? {
+        out ?: return null
+
+        when (out.peek()) {
+            NULL -> {
+                out.nextNull()
+                return null
+            }
+            else -> {
+                return LocalDate.parse(out.nextString(), formatter)
+            }
+        }
+    }
+}
+{{/gson}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/LocalDateTimeAdapter.kt.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/LocalDateTimeAdapter.kt.mustache
new file mode 100644
index 00000000000..0935b0053e5
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/LocalDateTimeAdapter.kt.mustache
@@ -0,0 +1,63 @@
+package {{packageName}}.infrastructure
+
+{{#moshi}}
+import com.squareup.moshi.FromJson
+import com.squareup.moshi.ToJson
+{{/moshi}}
+{{#gson}}
+import com.google.gson.TypeAdapter
+import com.google.gson.stream.JsonReader
+import com.google.gson.stream.JsonWriter
+import com.google.gson.stream.JsonToken.NULL
+import java.io.IOException
+{{/gson}}
+{{^threetenbp}}
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter
+{{/threetenbp}}
+{{#threetenbp}}
+import org.threeten.bp.LocalDateTime
+import org.threeten.bp.format.DateTimeFormatter
+{{/threetenbp}}
+
+{{#moshi}}
+{{#nonPublicApi}}internal {{/nonPublicApi}}class LocalDateTimeAdapter {
+    @ToJson
+    fun toJson(value: LocalDateTime): String {
+        return DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(value)
+    }
+
+    @FromJson
+    fun fromJson(value: String): LocalDateTime {
+        return LocalDateTime.parse(value, DateTimeFormatter.ISO_LOCAL_DATE_TIME)
+    }
+
+}
+{{/moshi}}
+{{#gson}}
+{{#nonPublicApi}}internal {{/nonPublicApi}}class LocalDateTimeAdapter(private val formatter: DateTimeFormatter = DateTimeFormatter.ISO_LOCAL_DATE_TIME) : TypeAdapter<LocalDateTime>() {
+    @Throws(IOException::class)
+    override fun write(out: JsonWriter?, value: LocalDateTime?) {
+        if (value == null) {
+            out?.nullValue()
+        } else {
+            out?.value(formatter.format(value))
+        }
+    }
+
+    @Throws(IOException::class)
+    override fun read(out: JsonReader?): LocalDateTime? {
+        out ?: return null
+
+        when (out.peek()) {
+            NULL -> {
+                out.nextNull()
+                return null
+            }
+            else -> {
+                return LocalDateTime.parse(out.nextString(), formatter)
+            }
+        }
+    }
+}
+{{/gson}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/Serializer.kt.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/Serializer.kt.mustache
new file mode 100644
index 00000000000..df4c33c26d2
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/Serializer.kt.mustache
@@ -0,0 +1,45 @@
+package {{packageName}}.infrastructure
+
+{{#moshi}}
+import com.squareup.moshi.Moshi
+import com.squareup.moshi.adapters.Rfc3339DateJsonAdapter
+import com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory
+{{/moshi}}
+{{#gson}}
+import com.google.gson.Gson
+import com.google.gson.GsonBuilder
+{{^threetenbp}}
+import java.time.LocalDate
+import java.time.LocalDateTime
+{{/threetenbp}}
+{{#threetenbp}}
+import org.threeten.bp.LocalDate
+import org.threeten.bp.LocalDateTime
+{{/threetenbp}}
+import java.util.UUID
+{{/gson}}
+import java.util.Date
+
+{{#nonPublicApi}}internal {{/nonPublicApi}}object Serializer {
+{{#moshi}}
+    @JvmStatic
+    val moshi: Moshi = Moshi.Builder()
+        .add(Date::class.java, Rfc3339DateJsonAdapter().nullSafe())
+        .add(LocalDateTimeAdapter())
+        .add(LocalDateAdapter())
+        .add(UUIDAdapter())
+        .add(ByteArrayAdapter())
+        .add(KotlinJsonAdapterFactory())
+        .build()
+{{/moshi}}
+{{#gson}}
+    @JvmStatic
+    val gson: Gson = GsonBuilder()
+        .registerTypeAdapter(Date::class.java, DateAdapter())
+        .registerTypeAdapter(LocalDateTime::class.java, LocalDateTimeAdapter())
+        .registerTypeAdapter(LocalDate::class.java, LocalDateAdapter())
+        .registerTypeAdapter(UUID::class.java, UUIDAdapter())
+        .registerTypeAdapter(ByteArray::class.java, ByteArrayAdapter())
+        .create()
+{{/gson}}
+}
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/UUIDAdapter.kt.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/UUIDAdapter.kt.mustache
new file mode 100644
index 00000000000..ad442305b17
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/infrastructure/UUIDAdapter.kt.mustache
@@ -0,0 +1,51 @@
+package {{packageName}}.infrastructure
+
+{{#moshi}}
+import com.squareup.moshi.FromJson
+import com.squareup.moshi.ToJson
+{{/moshi}}
+{{#gson}}
+import com.google.gson.TypeAdapter
+import com.google.gson.stream.JsonReader
+import com.google.gson.stream.JsonWriter
+import com.google.gson.stream.JsonToken.NULL
+import java.io.IOException
+{{/gson}}
+import java.util.UUID
+
+{{#moshi}}
+{{#nonPublicApi}}internal {{/nonPublicApi}}class UUIDAdapter {
+    @ToJson
+    fun toJson(uuid: UUID) = uuid.toString()
+
+    @FromJson
+    fun fromJson(s: String) = UUID.fromString(s)
+}
+{{/moshi}}
+{{#gson}}
+{{#nonPublicApi}}internal {{/nonPublicApi}}class UUIDAdapter : TypeAdapter<UUID>() {
+    @Throws(IOException::class)
+    override fun write(out: JsonWriter?, value: UUID?) {
+        if (value == null) {
+            out?.nullValue()
+        } else {
+            out?.value(value.toString())
+        }
+    }
+
+    @Throws(IOException::class)
+    override fun read(out: JsonReader?): UUID? {
+        out ?: return null
+
+        when (out.peek()) {
+            NULL -> {
+                out.nextNull()
+                return null
+            }
+            else -> {
+                return UUID.fromString(out.nextString())
+            }
+        }
+    }
+}
+{{/gson}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/pathParams.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/pathParams.mustache
new file mode 100644
index 00000000000..996a45473a9
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/pathParams.mustache
@@ -0,0 +1 @@
+{{#isPathParam}}@Path("{{baseName}}") {{paramName}}: {{{dataType}}}{{/isPathParam}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/queryParams.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/queryParams.mustache
new file mode 100644
index 00000000000..14c40f05e58
--- /dev/null
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/retrofit2/queryParams.mustache
@@ -0,0 +1 @@
+{{#isQueryParam}}@Query("{{baseName}}") {{paramName}}: {{#collectionFormat}}{{#isCollectionFormatMulti}}{{{dataType}}}{{/isCollectionFormatMulti}}{{^isCollectionFormatMulti}}{{{collectionFormat.toUpperCase}}}Params{{/isCollectionFormatMulti}}{{/collectionFormat}}{{^collectionFormat}}{{{dataType}}}{{/collectionFormat}}{{/isQueryParam}}
\ No newline at end of file
diff --git a/samples/client/petstore/kotlin-retrofit2/.openapi-generator-ignore b/samples/client/petstore/kotlin-retrofit2/.openapi-generator-ignore
new file mode 100644
index 00000000000..7484ee590a3
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/.openapi-generator-ignore
@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md
diff --git a/samples/client/petstore/kotlin-retrofit2/.openapi-generator/VERSION b/samples/client/petstore/kotlin-retrofit2/.openapi-generator/VERSION
new file mode 100644
index 00000000000..58592f031f6
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/.openapi-generator/VERSION
@@ -0,0 +1 @@
+4.2.3-SNAPSHOT
\ No newline at end of file
diff --git a/samples/client/petstore/kotlin-retrofit2/README.md b/samples/client/petstore/kotlin-retrofit2/README.md
new file mode 100644
index 00000000000..000a0a4606e
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/README.md
@@ -0,0 +1,80 @@
+# org.openapitools.client - Kotlin client library for OpenAPI Petstore
+
+## Requires
+
+
+## Build
+
+```
+./gradlew check assemble
+```
+
+This runs all tests and packages the library.
+
+## Features/Implementation Notes
+
+* Supports JSON inputs/outputs, File inputs, and Form inputs.
+* Supports collection formats for query parameters: csv, tsv, ssv, pipes.
+* Some Kotlin and Java types are fully qualified to avoid conflicts with types defined in OpenAPI definitions.
+
+
+<a name="documentation-for-api-endpoints"></a>
+## Documentation for API Endpoints
+
+All URIs are relative to *http://petstore.swagger.io/v2*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+*PetApi* | [**addPet**](docs/PetApi.md#addpet) | **POST** /pet | Add a new pet to the store
+*PetApi* | [**deletePet**](docs/PetApi.md#deletepet) | **DELETE** /pet/{petId} | Deletes a pet
+*PetApi* | [**findPetsByStatus**](docs/PetApi.md#findpetsbystatus) | **GET** /pet/findByStatus | Finds Pets by status
+*PetApi* | [**findPetsByTags**](docs/PetApi.md#findpetsbytags) | **GET** /pet/findByTags | Finds Pets by tags
+*PetApi* | [**getPetById**](docs/PetApi.md#getpetbyid) | **GET** /pet/{petId} | Find pet by ID
+*PetApi* | [**updatePet**](docs/PetApi.md#updatepet) | **PUT** /pet | Update an existing pet
+*PetApi* | [**updatePetWithForm**](docs/PetApi.md#updatepetwithform) | **POST** /pet/{petId} | Updates a pet in the store with form data
+*PetApi* | [**uploadFile**](docs/PetApi.md#uploadfile) | **POST** /pet/{petId}/uploadImage | uploads an image
+*StoreApi* | [**deleteOrder**](docs/StoreApi.md#deleteorder) | **DELETE** /store/order/{orderId} | Delete purchase order by ID
+*StoreApi* | [**getInventory**](docs/StoreApi.md#getinventory) | **GET** /store/inventory | Returns pet inventories by status
+*StoreApi* | [**getOrderById**](docs/StoreApi.md#getorderbyid) | **GET** /store/order/{orderId} | Find purchase order by ID
+*StoreApi* | [**placeOrder**](docs/StoreApi.md#placeorder) | **POST** /store/order | Place an order for a pet
+*UserApi* | [**createUser**](docs/UserApi.md#createuser) | **POST** /user | Create user
+*UserApi* | [**createUsersWithArrayInput**](docs/UserApi.md#createuserswitharrayinput) | **POST** /user/createWithArray | Creates list of users with given input array
+*UserApi* | [**createUsersWithListInput**](docs/UserApi.md#createuserswithlistinput) | **POST** /user/createWithList | Creates list of users with given input array
+*UserApi* | [**deleteUser**](docs/UserApi.md#deleteuser) | **DELETE** /user/{username} | Delete user
+*UserApi* | [**getUserByName**](docs/UserApi.md#getuserbyname) | **GET** /user/{username} | Get user by user name
+*UserApi* | [**loginUser**](docs/UserApi.md#loginuser) | **GET** /user/login | Logs user into the system
+*UserApi* | [**logoutUser**](docs/UserApi.md#logoutuser) | **GET** /user/logout | Logs out current logged in user session
+*UserApi* | [**updateUser**](docs/UserApi.md#updateuser) | **PUT** /user/{username} | Updated user
+
+
+<a name="documentation-for-models"></a>
+## Documentation for Models
+
+ - [org.openapitools.client.models.ApiResponse](docs/ApiResponse.md)
+ - [org.openapitools.client.models.Category](docs/Category.md)
+ - [org.openapitools.client.models.Order](docs/Order.md)
+ - [org.openapitools.client.models.Pet](docs/Pet.md)
+ - [org.openapitools.client.models.Tag](docs/Tag.md)
+ - [org.openapitools.client.models.User](docs/User.md)
+
+
+<a name="documentation-for-authorization"></a>
+## Documentation for Authorization
+
+<a name="api_key"></a>
+### api_key
+
+- **Type**: API key
+- **API key parameter name**: api_key
+- **Location**: HTTP header
+
+<a name="petstore_auth"></a>
+### petstore_auth
+
+- **Type**: OAuth
+- **Flow**: implicit
+- **Authorization URL**: http://petstore.swagger.io/api/oauth/dialog
+- **Scopes**: 
+  - write:pets: modify pets in your account
+  - read:pets: read your pets
+
diff --git a/samples/client/petstore/kotlin-retrofit2/build.gradle b/samples/client/petstore/kotlin-retrofit2/build.gradle
new file mode 100644
index 00000000000..ced65c34561
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/build.gradle
@@ -0,0 +1,40 @@
+group 'org.openapitools'
+version '1.0.0'
+
+wrapper {
+    gradleVersion = '4.9'
+    distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
+}
+
+buildscript {
+    ext.kotlin_version = '1.3.61'
+    ext.retrofitVersion = '2.6.2'
+
+    repositories {
+        mavenCentral()
+    }
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+    }
+}
+
+apply plugin: 'kotlin'
+
+repositories {
+    mavenCentral()
+}
+
+test {
+    useJUnitPlatform()
+}
+
+dependencies {
+    compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
+    compile "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
+    compile "com.squareup.moshi:moshi-kotlin:1.9.2"
+    compile "com.squareup.moshi:moshi-adapters:1.9.2"
+    compile "com.squareup.retrofit2:retrofit:$retrofitVersion"
+    compile "com.squareup.retrofit2:converter-moshi:$retrofitVersion"
+    compile "com.squareup.retrofit2:converter-scalars:$retrofitVersion"
+    testCompile "io.kotlintest:kotlintest-runner-junit5:3.1.0"
+}
diff --git a/samples/client/petstore/kotlin-retrofit2/docs/ApiResponse.md b/samples/client/petstore/kotlin-retrofit2/docs/ApiResponse.md
new file mode 100644
index 00000000000..6b4c6bf2779
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/docs/ApiResponse.md
@@ -0,0 +1,12 @@
+
+# ApiResponse
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**code** | **kotlin.Int** |  |  [optional]
+**type** | **kotlin.String** |  |  [optional]
+**message** | **kotlin.String** |  |  [optional]
+
+
+
diff --git a/samples/client/petstore/kotlin-retrofit2/docs/Category.md b/samples/client/petstore/kotlin-retrofit2/docs/Category.md
new file mode 100644
index 00000000000..2c28a670fc7
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/docs/Category.md
@@ -0,0 +1,11 @@
+
+# Category
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **kotlin.Long** |  |  [optional]
+**name** | **kotlin.String** |  |  [optional]
+
+
+
diff --git a/samples/client/petstore/kotlin-retrofit2/docs/Order.md b/samples/client/petstore/kotlin-retrofit2/docs/Order.md
new file mode 100644
index 00000000000..ef31dbf2f4f
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/docs/Order.md
@@ -0,0 +1,22 @@
+
+# Order
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **kotlin.Long** |  |  [optional]
+**petId** | **kotlin.Long** |  |  [optional]
+**quantity** | **kotlin.Int** |  |  [optional]
+**shipDate** | [**java.time.LocalDateTime**](java.time.LocalDateTime.md) |  |  [optional]
+**status** | [**inline**](#StatusEnum) | Order Status |  [optional]
+**complete** | **kotlin.Boolean** |  |  [optional]
+
+
+<a name="StatusEnum"></a>
+## Enum: status
+Name | Value
+---- | -----
+status | placed, approved, delivered
+
+
+
diff --git a/samples/client/petstore/kotlin-retrofit2/docs/Pet.md b/samples/client/petstore/kotlin-retrofit2/docs/Pet.md
new file mode 100644
index 00000000000..ec775600737
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/docs/Pet.md
@@ -0,0 +1,22 @@
+
+# Pet
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **kotlin.Long** |  |  [optional]
+**category** | [**Category**](Category.md) |  |  [optional]
+**name** | **kotlin.String** |  | 
+**photoUrls** | **kotlin.Array&lt;kotlin.String&gt;** |  | 
+**tags** | [**kotlin.Array&lt;Tag&gt;**](Tag.md) |  |  [optional]
+**status** | [**inline**](#StatusEnum) | pet status in the store |  [optional]
+
+
+<a name="StatusEnum"></a>
+## Enum: status
+Name | Value
+---- | -----
+status | available, pending, sold
+
+
+
diff --git a/samples/client/petstore/kotlin-retrofit2/docs/PetApi.md b/samples/client/petstore/kotlin-retrofit2/docs/PetApi.md
new file mode 100644
index 00000000000..ea93e174527
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/docs/PetApi.md
@@ -0,0 +1,405 @@
+# PetApi
+
+All URIs are relative to *http://petstore.swagger.io/v2*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**addPet**](PetApi.md#addPet) | **POST** /pet | Add a new pet to the store
+[**deletePet**](PetApi.md#deletePet) | **DELETE** /pet/{petId} | Deletes a pet
+[**findPetsByStatus**](PetApi.md#findPetsByStatus) | **GET** /pet/findByStatus | Finds Pets by status
+[**findPetsByTags**](PetApi.md#findPetsByTags) | **GET** /pet/findByTags | Finds Pets by tags
+[**getPetById**](PetApi.md#getPetById) | **GET** /pet/{petId} | Find pet by ID
+[**updatePet**](PetApi.md#updatePet) | **PUT** /pet | Update an existing pet
+[**updatePetWithForm**](PetApi.md#updatePetWithForm) | **POST** /pet/{petId} | Updates a pet in the store with form data
+[**uploadFile**](PetApi.md#uploadFile) | **POST** /pet/{petId}/uploadImage | uploads an image
+
+
+<a name="addPet"></a>
+# **addPet**
+> addPet(body)
+
+Add a new pet to the store
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = PetApi()
+val body : Pet =  // Pet | Pet object that needs to be added to the store
+try {
+    apiInstance.addPet(body)
+} catch (e: ClientException) {
+    println("4xx response calling PetApi#addPet")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling PetApi#addPet")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**Pet**](Pet.md)| Pet object that needs to be added to the store |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
+
+### HTTP request headers
+
+ - **Content-Type**: application/json, application/xml
+ - **Accept**: Not defined
+
+<a name="deletePet"></a>
+# **deletePet**
+> deletePet(petId, apiKey)
+
+Deletes a pet
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = PetApi()
+val petId : kotlin.Long = 789 // kotlin.Long | Pet id to delete
+val apiKey : kotlin.String = apiKey_example // kotlin.String | 
+try {
+    apiInstance.deletePet(petId, apiKey)
+} catch (e: ClientException) {
+    println("4xx response calling PetApi#deletePet")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling PetApi#deletePet")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **petId** | **kotlin.Long**| Pet id to delete |
+ **apiKey** | **kotlin.String**|  | [optional]
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: Not defined
+
+<a name="findPetsByStatus"></a>
+# **findPetsByStatus**
+> kotlin.Array&lt;Pet&gt; findPetsByStatus(status)
+
+Finds Pets by status
+
+Multiple status values can be provided with comma separated strings
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = PetApi()
+val status : kotlin.Array<kotlin.String> =  // kotlin.Array<kotlin.String> | Status values that need to be considered for filter
+try {
+    val result : kotlin.Array<Pet> = apiInstance.findPetsByStatus(status)
+    println(result)
+} catch (e: ClientException) {
+    println("4xx response calling PetApi#findPetsByStatus")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling PetApi#findPetsByStatus")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **status** | [**kotlin.Array&lt;kotlin.String&gt;**](kotlin.String.md)| Status values that need to be considered for filter | [enum: available, pending, sold]
+
+### Return type
+
+[**kotlin.Array&lt;Pet&gt;**](Pet.md)
+
+### Authorization
+
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/xml, application/json
+
+<a name="findPetsByTags"></a>
+# **findPetsByTags**
+> kotlin.Array&lt;Pet&gt; findPetsByTags(tags)
+
+Finds Pets by tags
+
+Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = PetApi()
+val tags : kotlin.Array<kotlin.String> =  // kotlin.Array<kotlin.String> | Tags to filter by
+try {
+    val result : kotlin.Array<Pet> = apiInstance.findPetsByTags(tags)
+    println(result)
+} catch (e: ClientException) {
+    println("4xx response calling PetApi#findPetsByTags")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling PetApi#findPetsByTags")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **tags** | [**kotlin.Array&lt;kotlin.String&gt;**](kotlin.String.md)| Tags to filter by |
+
+### Return type
+
+[**kotlin.Array&lt;Pet&gt;**](Pet.md)
+
+### Authorization
+
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/xml, application/json
+
+<a name="getPetById"></a>
+# **getPetById**
+> Pet getPetById(petId)
+
+Find pet by ID
+
+Returns a single pet
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = PetApi()
+val petId : kotlin.Long = 789 // kotlin.Long | ID of pet to return
+try {
+    val result : Pet = apiInstance.getPetById(petId)
+    println(result)
+} catch (e: ClientException) {
+    println("4xx response calling PetApi#getPetById")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling PetApi#getPetById")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **petId** | **kotlin.Long**| ID of pet to return |
+
+### Return type
+
+[**Pet**](Pet.md)
+
+### Authorization
+
+
+Configure api_key:
+    ApiClient.apiKey["api_key"] = ""
+    ApiClient.apiKeyPrefix["api_key"] = ""
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/xml, application/json
+
+<a name="updatePet"></a>
+# **updatePet**
+> updatePet(body)
+
+Update an existing pet
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = PetApi()
+val body : Pet =  // Pet | Pet object that needs to be added to the store
+try {
+    apiInstance.updatePet(body)
+} catch (e: ClientException) {
+    println("4xx response calling PetApi#updatePet")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling PetApi#updatePet")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**Pet**](Pet.md)| Pet object that needs to be added to the store |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
+
+### HTTP request headers
+
+ - **Content-Type**: application/json, application/xml
+ - **Accept**: Not defined
+
+<a name="updatePetWithForm"></a>
+# **updatePetWithForm**
+> updatePetWithForm(petId, name, status)
+
+Updates a pet in the store with form data
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = PetApi()
+val petId : kotlin.Long = 789 // kotlin.Long | ID of pet that needs to be updated
+val name : kotlin.String = name_example // kotlin.String | Updated name of the pet
+val status : kotlin.String = status_example // kotlin.String | Updated status of the pet
+try {
+    apiInstance.updatePetWithForm(petId, name, status)
+} catch (e: ClientException) {
+    println("4xx response calling PetApi#updatePetWithForm")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling PetApi#updatePetWithForm")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **petId** | **kotlin.Long**| ID of pet that needs to be updated |
+ **name** | **kotlin.String**| Updated name of the pet | [optional]
+ **status** | **kotlin.String**| Updated status of the pet | [optional]
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
+
+### HTTP request headers
+
+ - **Content-Type**: application/x-www-form-urlencoded
+ - **Accept**: Not defined
+
+<a name="uploadFile"></a>
+# **uploadFile**
+> ApiResponse uploadFile(petId, additionalMetadata, file)
+
+uploads an image
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = PetApi()
+val petId : kotlin.Long = 789 // kotlin.Long | ID of pet to update
+val additionalMetadata : kotlin.String = additionalMetadata_example // kotlin.String | Additional data to pass to server
+val file : java.io.File = BINARY_DATA_HERE // java.io.File | file to upload
+try {
+    val result : ApiResponse = apiInstance.uploadFile(petId, additionalMetadata, file)
+    println(result)
+} catch (e: ClientException) {
+    println("4xx response calling PetApi#uploadFile")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling PetApi#uploadFile")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **petId** | **kotlin.Long**| ID of pet to update |
+ **additionalMetadata** | **kotlin.String**| Additional data to pass to server | [optional]
+ **file** | **java.io.File**| file to upload | [optional]
+
+### Return type
+
+[**ApiResponse**](ApiResponse.md)
+
+### Authorization
+
+
+Configure petstore_auth:
+    ApiClient.accessToken = ""
+
+### HTTP request headers
+
+ - **Content-Type**: multipart/form-data
+ - **Accept**: application/json
+
diff --git a/samples/client/petstore/kotlin-retrofit2/docs/StoreApi.md b/samples/client/petstore/kotlin-retrofit2/docs/StoreApi.md
new file mode 100644
index 00000000000..f4986041af8
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/docs/StoreApi.md
@@ -0,0 +1,196 @@
+# StoreApi
+
+All URIs are relative to *http://petstore.swagger.io/v2*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**deleteOrder**](StoreApi.md#deleteOrder) | **DELETE** /store/order/{orderId} | Delete purchase order by ID
+[**getInventory**](StoreApi.md#getInventory) | **GET** /store/inventory | Returns pet inventories by status
+[**getOrderById**](StoreApi.md#getOrderById) | **GET** /store/order/{orderId} | Find purchase order by ID
+[**placeOrder**](StoreApi.md#placeOrder) | **POST** /store/order | Place an order for a pet
+
+
+<a name="deleteOrder"></a>
+# **deleteOrder**
+> deleteOrder(orderId)
+
+Delete purchase order by ID
+
+For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = StoreApi()
+val orderId : kotlin.String = orderId_example // kotlin.String | ID of the order that needs to be deleted
+try {
+    apiInstance.deleteOrder(orderId)
+} catch (e: ClientException) {
+    println("4xx response calling StoreApi#deleteOrder")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling StoreApi#deleteOrder")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **orderId** | **kotlin.String**| ID of the order that needs to be deleted |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: Not defined
+
+<a name="getInventory"></a>
+# **getInventory**
+> kotlin.collections.Map&lt;kotlin.String, kotlin.Int&gt; getInventory()
+
+Returns pet inventories by status
+
+Returns a map of status codes to quantities
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = StoreApi()
+try {
+    val result : kotlin.collections.Map<kotlin.String, kotlin.Int> = apiInstance.getInventory()
+    println(result)
+} catch (e: ClientException) {
+    println("4xx response calling StoreApi#getInventory")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling StoreApi#getInventory")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+This endpoint does not need any parameter.
+
+### Return type
+
+**kotlin.collections.Map&lt;kotlin.String, kotlin.Int&gt;**
+
+### Authorization
+
+
+Configure api_key:
+    ApiClient.apiKey["api_key"] = ""
+    ApiClient.apiKeyPrefix["api_key"] = ""
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/json
+
+<a name="getOrderById"></a>
+# **getOrderById**
+> Order getOrderById(orderId)
+
+Find purchase order by ID
+
+For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = StoreApi()
+val orderId : kotlin.Long = 789 // kotlin.Long | ID of pet that needs to be fetched
+try {
+    val result : Order = apiInstance.getOrderById(orderId)
+    println(result)
+} catch (e: ClientException) {
+    println("4xx response calling StoreApi#getOrderById")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling StoreApi#getOrderById")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **orderId** | **kotlin.Long**| ID of pet that needs to be fetched |
+
+### Return type
+
+[**Order**](Order.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/xml, application/json
+
+<a name="placeOrder"></a>
+# **placeOrder**
+> Order placeOrder(body)
+
+Place an order for a pet
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = StoreApi()
+val body : Order =  // Order | order placed for purchasing the pet
+try {
+    val result : Order = apiInstance.placeOrder(body)
+    println(result)
+} catch (e: ClientException) {
+    println("4xx response calling StoreApi#placeOrder")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling StoreApi#placeOrder")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**Order**](Order.md)| order placed for purchasing the pet |
+
+### Return type
+
+[**Order**](Order.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/xml, application/json
+
diff --git a/samples/client/petstore/kotlin-retrofit2/docs/Tag.md b/samples/client/petstore/kotlin-retrofit2/docs/Tag.md
new file mode 100644
index 00000000000..60ce1bcdbad
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/docs/Tag.md
@@ -0,0 +1,11 @@
+
+# Tag
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **kotlin.Long** |  |  [optional]
+**name** | **kotlin.String** |  |  [optional]
+
+
+
diff --git a/samples/client/petstore/kotlin-retrofit2/docs/User.md b/samples/client/petstore/kotlin-retrofit2/docs/User.md
new file mode 100644
index 00000000000..e801729b5ed
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/docs/User.md
@@ -0,0 +1,17 @@
+
+# User
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **kotlin.Long** |  |  [optional]
+**username** | **kotlin.String** |  |  [optional]
+**firstName** | **kotlin.String** |  |  [optional]
+**lastName** | **kotlin.String** |  |  [optional]
+**email** | **kotlin.String** |  |  [optional]
+**password** | **kotlin.String** |  |  [optional]
+**phone** | **kotlin.String** |  |  [optional]
+**userStatus** | **kotlin.Int** | User Status |  [optional]
+
+
+
diff --git a/samples/client/petstore/kotlin-retrofit2/docs/UserApi.md b/samples/client/petstore/kotlin-retrofit2/docs/UserApi.md
new file mode 100644
index 00000000000..0f55f06bc62
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/docs/UserApi.md
@@ -0,0 +1,376 @@
+# UserApi
+
+All URIs are relative to *http://petstore.swagger.io/v2*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**createUser**](UserApi.md#createUser) | **POST** /user | Create user
+[**createUsersWithArrayInput**](UserApi.md#createUsersWithArrayInput) | **POST** /user/createWithArray | Creates list of users with given input array
+[**createUsersWithListInput**](UserApi.md#createUsersWithListInput) | **POST** /user/createWithList | Creates list of users with given input array
+[**deleteUser**](UserApi.md#deleteUser) | **DELETE** /user/{username} | Delete user
+[**getUserByName**](UserApi.md#getUserByName) | **GET** /user/{username} | Get user by user name
+[**loginUser**](UserApi.md#loginUser) | **GET** /user/login | Logs user into the system
+[**logoutUser**](UserApi.md#logoutUser) | **GET** /user/logout | Logs out current logged in user session
+[**updateUser**](UserApi.md#updateUser) | **PUT** /user/{username} | Updated user
+
+
+<a name="createUser"></a>
+# **createUser**
+> createUser(body)
+
+Create user
+
+This can only be done by the logged in user.
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = UserApi()
+val body : User =  // User | Created user object
+try {
+    apiInstance.createUser(body)
+} catch (e: ClientException) {
+    println("4xx response calling UserApi#createUser")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling UserApi#createUser")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**User**](User.md)| Created user object |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: Not defined
+
+<a name="createUsersWithArrayInput"></a>
+# **createUsersWithArrayInput**
+> createUsersWithArrayInput(body)
+
+Creates list of users with given input array
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = UserApi()
+val body : kotlin.Array<User> =  // kotlin.Array<User> | List of user object
+try {
+    apiInstance.createUsersWithArrayInput(body)
+} catch (e: ClientException) {
+    println("4xx response calling UserApi#createUsersWithArrayInput")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling UserApi#createUsersWithArrayInput")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**kotlin.Array&lt;User&gt;**](User.md)| List of user object |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: Not defined
+
+<a name="createUsersWithListInput"></a>
+# **createUsersWithListInput**
+> createUsersWithListInput(body)
+
+Creates list of users with given input array
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = UserApi()
+val body : kotlin.Array<User> =  // kotlin.Array<User> | List of user object
+try {
+    apiInstance.createUsersWithListInput(body)
+} catch (e: ClientException) {
+    println("4xx response calling UserApi#createUsersWithListInput")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling UserApi#createUsersWithListInput")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**kotlin.Array&lt;User&gt;**](User.md)| List of user object |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: Not defined
+
+<a name="deleteUser"></a>
+# **deleteUser**
+> deleteUser(username)
+
+Delete user
+
+This can only be done by the logged in user.
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = UserApi()
+val username : kotlin.String = username_example // kotlin.String | The name that needs to be deleted
+try {
+    apiInstance.deleteUser(username)
+} catch (e: ClientException) {
+    println("4xx response calling UserApi#deleteUser")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling UserApi#deleteUser")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **username** | **kotlin.String**| The name that needs to be deleted |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: Not defined
+
+<a name="getUserByName"></a>
+# **getUserByName**
+> User getUserByName(username)
+
+Get user by user name
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = UserApi()
+val username : kotlin.String = username_example // kotlin.String | The name that needs to be fetched. Use user1 for testing.
+try {
+    val result : User = apiInstance.getUserByName(username)
+    println(result)
+} catch (e: ClientException) {
+    println("4xx response calling UserApi#getUserByName")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling UserApi#getUserByName")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **username** | **kotlin.String**| The name that needs to be fetched. Use user1 for testing. |
+
+### Return type
+
+[**User**](User.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/xml, application/json
+
+<a name="loginUser"></a>
+# **loginUser**
+> kotlin.String loginUser(username, password)
+
+Logs user into the system
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = UserApi()
+val username : kotlin.String = username_example // kotlin.String | The user name for login
+val password : kotlin.String = password_example // kotlin.String | The password for login in clear text
+try {
+    val result : kotlin.String = apiInstance.loginUser(username, password)
+    println(result)
+} catch (e: ClientException) {
+    println("4xx response calling UserApi#loginUser")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling UserApi#loginUser")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **username** | **kotlin.String**| The user name for login |
+ **password** | **kotlin.String**| The password for login in clear text |
+
+### Return type
+
+**kotlin.String**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/xml, application/json
+
+<a name="logoutUser"></a>
+# **logoutUser**
+> logoutUser()
+
+Logs out current logged in user session
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = UserApi()
+try {
+    apiInstance.logoutUser()
+} catch (e: ClientException) {
+    println("4xx response calling UserApi#logoutUser")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling UserApi#logoutUser")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+This endpoint does not need any parameter.
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: Not defined
+
+<a name="updateUser"></a>
+# **updateUser**
+> updateUser(username, body)
+
+Updated user
+
+This can only be done by the logged in user.
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = UserApi()
+val username : kotlin.String = username_example // kotlin.String | name that need to be deleted
+val body : User =  // User | Updated user object
+try {
+    apiInstance.updateUser(username, body)
+} catch (e: ClientException) {
+    println("4xx response calling UserApi#updateUser")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling UserApi#updateUser")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **username** | **kotlin.String**| name that need to be deleted |
+ **body** | [**User**](User.md)| Updated user object |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: Not defined
+
diff --git a/samples/client/petstore/kotlin-retrofit2/settings.gradle b/samples/client/petstore/kotlin-retrofit2/settings.gradle
new file mode 100644
index 00000000000..24c556e079c
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/settings.gradle
@@ -0,0 +1,2 @@
+
+rootProject.name = 'kotlin-petstore-retrofit2'
\ No newline at end of file
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/PetApi.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/PetApi.kt
new file mode 100644
index 00000000000..75f3323445c
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/PetApi.kt
@@ -0,0 +1,41 @@
+package org.openapitools.client.apis
+
+import org.openapitools.client.infrastructure.CollectionFormats.*
+import retrofit2.http.*
+import retrofit2.Call
+import okhttp3.RequestBody
+import okhttp3.ResponseBody
+import okhttp3.MultipartBody
+
+import org.openapitools.client.models.ApiResponse
+import org.openapitools.client.models.Pet
+
+interface PetApi {
+    @POST("/pet")
+    fun addPet(@Body body: Pet): Call<Unit>
+
+    @DELETE("/pet/{petId}")
+    fun deletePet(@Path("petId") petId: kotlin.Long, @Header("api_key") apiKey: kotlin.String): Call<Unit>
+
+    @GET("/pet/findByStatus")
+    fun findPetsByStatus(@Query("status") status: CSVParams): Call<kotlin.Array<Pet>>
+
+    @Deprecated("This api was deprecated")
+    @GET("/pet/findByTags")
+    fun findPetsByTags(@Query("tags") tags: CSVParams): Call<kotlin.Array<Pet>>
+
+    @GET("/pet/{petId}")
+    fun getPetById(@Path("petId") petId: kotlin.Long): Call<Pet>
+
+    @PUT("/pet")
+    fun updatePet(@Body body: Pet): Call<Unit>
+
+    @FormUrlEncoded
+    @POST("/pet/{petId}")
+    fun updatePetWithForm(@Path("petId") petId: kotlin.Long, @Field("name") name: kotlin.String, @Field("status") status: kotlin.String): Call<Unit>
+
+    @Multipart
+    @POST("/pet/{petId}/uploadImage")
+    fun uploadFile(@Path("petId") petId: kotlin.Long, @Part("additionalMetadata") additionalMetadata: kotlin.String, @Part file: MultipartBody.Part ): Call<ApiResponse>
+
+}
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/StoreApi.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/StoreApi.kt
new file mode 100644
index 00000000000..cb0d5b8fa1b
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/StoreApi.kt
@@ -0,0 +1,25 @@
+package org.openapitools.client.apis
+
+import org.openapitools.client.infrastructure.CollectionFormats.*
+import retrofit2.http.*
+import retrofit2.Call
+import okhttp3.RequestBody
+import okhttp3.ResponseBody
+import okhttp3.MultipartBody
+
+import org.openapitools.client.models.Order
+
+interface StoreApi {
+    @DELETE("/store/order/{orderId}")
+    fun deleteOrder(@Path("orderId") orderId: kotlin.String): Call<Unit>
+
+    @GET("/store/inventory")
+    fun getInventory(): Call<kotlin.collections.Map<kotlin.String, kotlin.Int>>
+
+    @GET("/store/order/{orderId}")
+    fun getOrderById(@Path("orderId") orderId: kotlin.Long): Call<Order>
+
+    @POST("/store/order")
+    fun placeOrder(@Body body: Order): Call<Order>
+
+}
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/UserApi.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/UserApi.kt
new file mode 100644
index 00000000000..84a6cd43e5e
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/apis/UserApi.kt
@@ -0,0 +1,37 @@
+package org.openapitools.client.apis
+
+import org.openapitools.client.infrastructure.CollectionFormats.*
+import retrofit2.http.*
+import retrofit2.Call
+import okhttp3.RequestBody
+import okhttp3.ResponseBody
+import okhttp3.MultipartBody
+
+import org.openapitools.client.models.User
+
+interface UserApi {
+    @POST("/user")
+    fun createUser(@Body body: User): Call<Unit>
+
+    @POST("/user/createWithArray")
+    fun createUsersWithArrayInput(@Body body: kotlin.Array<User>): Call<Unit>
+
+    @POST("/user/createWithList")
+    fun createUsersWithListInput(@Body body: kotlin.Array<User>): Call<Unit>
+
+    @DELETE("/user/{username}")
+    fun deleteUser(@Path("username") username: kotlin.String): Call<Unit>
+
+    @GET("/user/{username}")
+    fun getUserByName(@Path("username") username: kotlin.String): Call<User>
+
+    @GET("/user/login")
+    fun loginUser(@Query("username") username: kotlin.String, @Query("password") password: kotlin.String): Call<kotlin.String>
+
+    @GET("/user/logout")
+    fun logoutUser(): Call<Unit>
+
+    @PUT("/user/{username}")
+    fun updateUser(@Path("username") username: kotlin.String, @Body body: User): Call<Unit>
+
+}
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
new file mode 100644
index 00000000000..b539fda7438
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
@@ -0,0 +1,33 @@
+package org.openapitools.client.infrastructure
+
+import okhttp3.OkHttpClient
+import retrofit2.Retrofit
+import retrofit2.converter.scalars.ScalarsConverterFactory
+import retrofit2.converter.moshi.MoshiConverterFactory
+
+class ApiClient(
+    private var baseUrl: String = "http://petstore.swagger.io/v2",
+    private var okHttpClient: OkHttpClient
+) {
+    init {
+        normalizeBaseUrl()
+    }
+
+    val retrofitBuilder: Retrofit.Builder by lazy {
+
+        Retrofit.Builder()
+        .baseUrl(baseUrl)
+        .addConverterFactory(ScalarsConverterFactory.create())
+        .addConverterFactory(MoshiConverterFactory.create(Serializer.moshi))
+    }
+
+    fun <S> createService(serviceClass: Class<S>): S {
+        return retrofitBuilder.client(okHttpClient).build().create(serviceClass)
+    }
+
+    private fun normalizeBaseUrl() {
+        if (!baseUrl.endsWith("/")) {
+            baseUrl += "/"
+        }
+    }
+}
\ No newline at end of file
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ByteArrayAdapter.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ByteArrayAdapter.kt
new file mode 100644
index 00000000000..ff5e2a81ee8
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/ByteArrayAdapter.kt
@@ -0,0 +1,12 @@
+package org.openapitools.client.infrastructure
+
+import com.squareup.moshi.FromJson
+import com.squareup.moshi.ToJson
+
+class ByteArrayAdapter {
+    @ToJson
+    fun toJson(data: ByteArray): String = String(data)
+
+    @FromJson
+    fun fromJson(data: String): ByteArray = data.toByteArray()
+}
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/CollectionFormats.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/CollectionFormats.kt
new file mode 100644
index 00000000000..001e99325d2
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/CollectionFormats.kt
@@ -0,0 +1,56 @@
+package org.openapitools.client.infrastructure
+
+class CollectionFormats {
+
+    open class CSVParams {
+
+        var params: List<String>
+
+        constructor(params: List<String>) {
+            this.params = params
+        }
+
+        constructor(vararg params: String) {
+            this.params = listOf(*params)
+        }
+
+        override fun toString(): String {
+            return params.joinToString(",")
+        }
+    }
+
+    open class SSVParams : CSVParams {
+
+        constructor(params: List<String>) : super(params)
+
+        constructor(vararg params: String) : super(*params)
+
+        override fun toString(): String {
+            return params.joinToString(" ")
+        }
+    }
+
+    class TSVParams : CSVParams {
+
+        constructor(params: List<String>) : super(params)
+
+        constructor(vararg params: String) : super(*params)
+
+        override fun toString(): String {
+            return params.joinToString("\t")
+        }
+    }
+
+    class PIPESParams : CSVParams {
+
+        constructor(params: List<String>) : super(params)
+
+        constructor(vararg params: String) : super(*params)
+
+        override fun toString(): String {
+            return params.joinToString("|")
+        }
+    }
+
+    class SPACEParams : SSVParams()
+}
\ No newline at end of file
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateAdapter.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateAdapter.kt
new file mode 100644
index 00000000000..b2e1654479a
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateAdapter.kt
@@ -0,0 +1,19 @@
+package org.openapitools.client.infrastructure
+
+import com.squareup.moshi.FromJson
+import com.squareup.moshi.ToJson
+import java.time.LocalDate
+import java.time.format.DateTimeFormatter
+
+class LocalDateAdapter {
+    @ToJson
+    fun toJson(value: LocalDate): String {
+        return DateTimeFormatter.ISO_LOCAL_DATE.format(value)
+    }
+
+    @FromJson
+    fun fromJson(value: String): LocalDate {
+        return LocalDate.parse(value, DateTimeFormatter.ISO_LOCAL_DATE)
+    }
+
+}
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateTimeAdapter.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateTimeAdapter.kt
new file mode 100644
index 00000000000..e082db94811
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/LocalDateTimeAdapter.kt
@@ -0,0 +1,19 @@
+package org.openapitools.client.infrastructure
+
+import com.squareup.moshi.FromJson
+import com.squareup.moshi.ToJson
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter
+
+class LocalDateTimeAdapter {
+    @ToJson
+    fun toJson(value: LocalDateTime): String {
+        return DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(value)
+    }
+
+    @FromJson
+    fun fromJson(value: String): LocalDateTime {
+        return LocalDateTime.parse(value, DateTimeFormatter.ISO_LOCAL_DATE_TIME)
+    }
+
+}
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/Serializer.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/Serializer.kt
new file mode 100644
index 00000000000..7c5a353e0f7
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/Serializer.kt
@@ -0,0 +1,18 @@
+package org.openapitools.client.infrastructure
+
+import com.squareup.moshi.Moshi
+import com.squareup.moshi.adapters.Rfc3339DateJsonAdapter
+import com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory
+import java.util.Date
+
+object Serializer {
+    @JvmStatic
+    val moshi: Moshi = Moshi.Builder()
+        .add(Date::class.java, Rfc3339DateJsonAdapter().nullSafe())
+        .add(LocalDateTimeAdapter())
+        .add(LocalDateAdapter())
+        .add(UUIDAdapter())
+        .add(ByteArrayAdapter())
+        .add(KotlinJsonAdapterFactory())
+        .build()
+}
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/UUIDAdapter.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/UUIDAdapter.kt
new file mode 100644
index 00000000000..a4a44cc18b7
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/infrastructure/UUIDAdapter.kt
@@ -0,0 +1,13 @@
+package org.openapitools.client.infrastructure
+
+import com.squareup.moshi.FromJson
+import com.squareup.moshi.ToJson
+import java.util.UUID
+
+class UUIDAdapter {
+    @ToJson
+    fun toJson(uuid: UUID) = uuid.toString()
+
+    @FromJson
+    fun fromJson(s: String) = UUID.fromString(s)
+}
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/ApiResponse.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/ApiResponse.kt
new file mode 100644
index 00000000000..47766821f18
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/ApiResponse.kt
@@ -0,0 +1,33 @@
+/**
+* OpenAPI Petstore
+* This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* The version of the OpenAPI document: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+package org.openapitools.client.models
+
+
+import com.squareup.moshi.Json
+/**
+ * Describes the result of uploading an image resource
+ * @param code 
+ * @param type 
+ * @param message 
+ */
+
+data class ApiResponse (
+    @Json(name = "code")
+    val code: kotlin.Int? = null,
+    @Json(name = "type")
+    val type: kotlin.String? = null,
+    @Json(name = "message")
+    val message: kotlin.String? = null
+) 
+
+
+
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Category.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Category.kt
new file mode 100644
index 00000000000..edb16cc1270
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Category.kt
@@ -0,0 +1,30 @@
+/**
+* OpenAPI Petstore
+* This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* The version of the OpenAPI document: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+package org.openapitools.client.models
+
+
+import com.squareup.moshi.Json
+/**
+ * A category for a pet
+ * @param id 
+ * @param name 
+ */
+
+data class Category (
+    @Json(name = "id")
+    val id: kotlin.Long? = null,
+    @Json(name = "name")
+    val name: kotlin.String? = null
+) 
+
+
+
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Order.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Order.kt
new file mode 100644
index 00000000000..bcdb149159b
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Order.kt
@@ -0,0 +1,55 @@
+/**
+* OpenAPI Petstore
+* This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* The version of the OpenAPI document: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+package org.openapitools.client.models
+
+
+import com.squareup.moshi.Json
+/**
+ * An order for a pets from the pet store
+ * @param id 
+ * @param petId 
+ * @param quantity 
+ * @param shipDate 
+ * @param status Order Status
+ * @param complete 
+ */
+
+data class Order (
+    @Json(name = "id")
+    val id: kotlin.Long? = null,
+    @Json(name = "petId")
+    val petId: kotlin.Long? = null,
+    @Json(name = "quantity")
+    val quantity: kotlin.Int? = null,
+    @Json(name = "shipDate")
+    val shipDate: java.time.LocalDateTime? = null,
+    /* Order Status */
+    @Json(name = "status")
+    val status: Order.Status? = null,
+    @Json(name = "complete")
+    val complete: kotlin.Boolean? = null
+) 
+
+
+{
+    /**
+    * Order Status
+    * Values: placed,approved,delivered
+    */
+    
+    enum class Status(val value: kotlin.String){
+        @Json(name = "placed") placed("placed"),
+        @Json(name = "approved") approved("approved"),
+        @Json(name = "delivered") delivered("delivered");
+    }
+}
+
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Pet.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Pet.kt
new file mode 100644
index 00000000000..f6f7371601f
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Pet.kt
@@ -0,0 +1,57 @@
+/**
+* OpenAPI Petstore
+* This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* The version of the OpenAPI document: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+package org.openapitools.client.models
+
+import org.openapitools.client.models.Category
+import org.openapitools.client.models.Tag
+
+import com.squareup.moshi.Json
+/**
+ * A pet for sale in the pet store
+ * @param id 
+ * @param category 
+ * @param name 
+ * @param photoUrls 
+ * @param tags 
+ * @param status pet status in the store
+ */
+
+data class Pet (
+    @Json(name = "name")
+    val name: kotlin.String,
+    @Json(name = "photoUrls")
+    val photoUrls: kotlin.Array<kotlin.String>,
+    @Json(name = "id")
+    val id: kotlin.Long? = null,
+    @Json(name = "category")
+    val category: Category? = null,
+    @Json(name = "tags")
+    val tags: kotlin.Array<Tag>? = null,
+    /* pet status in the store */
+    @Json(name = "status")
+    val status: Pet.Status? = null
+) 
+
+
+{
+    /**
+    * pet status in the store
+    * Values: available,pending,sold
+    */
+    
+    enum class Status(val value: kotlin.String){
+        @Json(name = "available") available("available"),
+        @Json(name = "pending") pending("pending"),
+        @Json(name = "sold") sold("sold");
+    }
+}
+
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Tag.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Tag.kt
new file mode 100644
index 00000000000..05dc7c9afef
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/Tag.kt
@@ -0,0 +1,30 @@
+/**
+* OpenAPI Petstore
+* This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* The version of the OpenAPI document: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+package org.openapitools.client.models
+
+
+import com.squareup.moshi.Json
+/**
+ * A tag for a pet
+ * @param id 
+ * @param name 
+ */
+
+data class Tag (
+    @Json(name = "id")
+    val id: kotlin.Long? = null,
+    @Json(name = "name")
+    val name: kotlin.String? = null
+) 
+
+
+
diff --git a/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/User.kt b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/User.kt
new file mode 100644
index 00000000000..537b01d3c27
--- /dev/null
+++ b/samples/client/petstore/kotlin-retrofit2/src/main/kotlin/org/openapitools/client/models/User.kt
@@ -0,0 +1,49 @@
+/**
+* OpenAPI Petstore
+* This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* The version of the OpenAPI document: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+package org.openapitools.client.models
+
+
+import com.squareup.moshi.Json
+/**
+ * A User who is purchasing from the pet store
+ * @param id 
+ * @param username 
+ * @param firstName 
+ * @param lastName 
+ * @param email 
+ * @param password 
+ * @param phone 
+ * @param userStatus User Status
+ */
+
+data class User (
+    @Json(name = "id")
+    val id: kotlin.Long? = null,
+    @Json(name = "username")
+    val username: kotlin.String? = null,
+    @Json(name = "firstName")
+    val firstName: kotlin.String? = null,
+    @Json(name = "lastName")
+    val lastName: kotlin.String? = null,
+    @Json(name = "email")
+    val email: kotlin.String? = null,
+    @Json(name = "password")
+    val password: kotlin.String? = null,
+    @Json(name = "phone")
+    val phone: kotlin.String? = null,
+    /* User Status */
+    @Json(name = "userStatus")
+    val userStatus: kotlin.Int? = null
+) 
+
+
+