diff --git a/README.md b/README.md
index 862e57a..a299fbc 100644
--- a/README.md
+++ b/README.md
@@ -13,14 +13,14 @@ automatic retry logic.
 <dependency>
     <groupId>com.volcengine</groupId>
     <artifactId>ark-runtime</artifactId>
-    <version>0.1.0</version>
+    <version>0.2.0</version>
 </dependency>
 ```
 
 ### Gradle
 
 ```groovy
-implementation 'com.volcengine:ark-runtime:0.1.0'
+implementation 'com.volcengine:ark-runtime:0.2.0'
 ```
 
 ## Usage
diff --git a/VERSION b/VERSION
index 6e8bf73..0ea3a94 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.1.0
+0.2.0
diff --git a/pom.xml b/pom.xml
index 4998058..7d2faf0 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>com.volcengine</groupId>
     <artifactId>ark-runtime</artifactId>
-    <version>0.1.0</version>
+    <version>0.2.0</version>
     <packaging>jar</packaging>
 
     <name>ark-runtime</name>
diff --git a/src/main/java/com/volcengine/ark/runtime/models/images/Usage.java b/src/main/java/com/volcengine/ark/runtime/models/images/Usage.java
index 98d7946..50d30f7 100644
--- a/src/main/java/com/volcengine/ark/runtime/models/images/Usage.java
+++ b/src/main/java/com/volcengine/ark/runtime/models/images/Usage.java
@@ -34,7 +34,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.21.0")
 public class Usage {
   public static final String JSON_PROPERTY_INPUT_IMAGES = "input_images";
-  @javax.annotation.Nonnull
+  @javax.annotation.Nullable
   private Long inputImages;
 
   public static final String JSON_PROPERTY_GENERATED_IMAGES = "generated_images";
@@ -56,28 +56,28 @@ public class Usage {
   public Usage() {
   }
 
-  public Usage inputImages(@javax.annotation.Nonnull Long inputImages) {
+  public Usage inputImages(@javax.annotation.Nullable Long inputImages) {
 
     this.inputImages = inputImages;
     return this;
   }
 
   /**
-   * Number of reference images supplied by the client.
+   * Number of reference images supplied by the client. May be absent in responses from older services.
    * @return inputImages
    */
-  @javax.annotation.Nonnull
-  @JsonProperty(value = JSON_PROPERTY_INPUT_IMAGES, required = true)
-  @JsonInclude(value = JsonInclude.Include.ALWAYS)
+  @javax.annotation.Nullable
+  @JsonProperty(value = JSON_PROPERTY_INPUT_IMAGES, required = false)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
 
   public Long getInputImages() {
     return inputImages;
   }
 
 
-  @JsonProperty(value = JSON_PROPERTY_INPUT_IMAGES, required = true)
-  @JsonInclude(value = JsonInclude.Include.ALWAYS)
-  public void setInputImages(@javax.annotation.Nonnull Long inputImages) {
+  @JsonProperty(value = JSON_PROPERTY_INPUT_IMAGES, required = false)
+  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
+  public void setInputImages(@javax.annotation.Nullable Long inputImages) {
     this.inputImages = inputImages;
   }