fix: Fix service_tier enums.

src/main/java/com/google/genai/Models.java

@@ -1871,8 +1871,11 @@ ObjectNode generateContentConfigToVertex(
           Common.getValueByPath(fromObject, new String[] {"modelArmorConfig"}));
     }
 
-    if (!Common.isZero(Common.getValueByPath(fromObject, new String[] {"serviceTier"}))) {
-      throw new IllegalArgumentException("serviceTier parameter is not supported in Vertex AI.");
+    if (Common.getValueByPath(fromObject, new String[] {"serviceTier"}) != null) {
+      Common.setValueByPath(
+          parentObject,
+          new String[] {"serviceTier"},
+          Common.getValueByPath(fromObject, new String[] {"serviceTier"}));
     }
 
     return toObject;

src/main/java/com/google/genai/types/GenerateContentConfig.java

@@ -239,7 +239,7 @@ public abstract class GenerateContentConfig extends JsonSerializable {
   @JsonProperty("modelArmorConfig")
   public abstract Optional<ModelArmorConfig> modelArmorConfig();
 
-  /** The service tier to use for the request. For example, SERVICE_TIER_FLEX. */
+  /** The service tier to use for the request. For example, ServiceTier.FLEX. */
   @JsonProperty("serviceTier")
   public abstract Optional<ServiceTier> serviceTier();
 
@@ -1110,7 +1110,7 @@ public Builder clearModelArmorConfig() {
     /**
      * Setter for serviceTier.
      *
-     * <p>serviceTier: The service tier to use for the request. For example, SERVICE_TIER_FLEX.
+     * <p>serviceTier: The service tier to use for the request. For example, ServiceTier.FLEX.
      */
     @JsonProperty("serviceTier")
     public abstract Builder serviceTier(ServiceTier serviceTier);
@@ -1128,7 +1128,7 @@ public Builder clearServiceTier() {
     /**
      * Setter for serviceTier given a known enum.
      *
-     * <p>serviceTier: The service tier to use for the request. For example, SERVICE_TIER_FLEX.
+     * <p>serviceTier: The service tier to use for the request. For example, ServiceTier.FLEX.
      */
     @CanIgnoreReturnValue
     public Builder serviceTier(ServiceTier.Known knownType) {
@@ -1138,7 +1138,7 @@ public Builder serviceTier(ServiceTier.Known knownType) {
     /**
      * Setter for serviceTier given a string.
      *
-     * <p>serviceTier: The service tier to use for the request. For example, SERVICE_TIER_FLEX.
+     * <p>serviceTier: The service tier to use for the request. For example, ServiceTier.FLEX.
      */
     @CanIgnoreReturnValue
     public Builder serviceTier(String serviceTier) {

src/main/java/com/google/genai/types/ImagePromptLanguage.java

@@ -29,30 +29,48 @@ public class ImagePromptLanguage {
   /** Enum representing the known values for ImagePromptLanguage. */
   public enum Known {
     /** Auto-detect the language. */
-    AUTO,
+    AUTO("auto"),
 
     /** English */
-    EN,
+    EN("en"),
 
     /** Japanese */
-    JA,
+    JA("ja"),
 
     /** Korean */
-    KO,
+    KO("ko"),
 
     /** Hindi */
-    HI,
+    HI("hi"),
 
     /** Chinese */
-    ZH,
+    ZH("zh"),
 
     /** Portuguese */
-    PT,
+    PT("pt"),
 
     /** Spanish */
-    ES,
+    ES("es"),
 
-    IMAGE_PROMPT_LANGUAGE_UNSPECIFIED
+    IMAGE_PROMPT_LANGUAGE_UNSPECIFIED;
+    private final String value;
+
+    Known() {
+      this.value = this.name();
+    }
+
+    Known(String value) {
+      this.value = value;
+    }
+
+    public String value() {
+      return value;
+    }
+
+    @Override
+    public String toString() {
+      return value;
+    }
   }
 
   private Known imagePromptLanguageEnum;

src/main/java/com/google/genai/types/ServiceTier.java

@@ -29,16 +29,36 @@ public class ServiceTier {
   /** Enum representing the known values for ServiceTier. */
   public enum Known {
     /** Default service tier, which is standard. */
-    SERVICE_TIER_UNSPECIFIED,
+    UNSPECIFIED("unspecified"),
 
     /** Flex service tier. */
-    SERVICE_TIER_FLEX,
+    FLEX("flex"),
 
     /** Standard service tier. */
-    SERVICE_TIER_STANDARD,
+    STANDARD("standard"),
 
     /** Priority service tier. */
-    SERVICE_TIER_PRIORITY
+    PRIORITY("priority"),
+
+    SERVICE_TIER_UNSPECIFIED;
+    private final String value;
+
+    Known() {
+      this.value = this.name();
+    }
+
+    Known(String value) {
+      this.value = value;
+    }
+
+    public String value() {
+      return value;
+    }
+
+    @Override
+    public String toString() {
+      return value;
+    }
   }
 
   private Known serviceTierEnum;