feat: Add service tier to GenerateContent.

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

@@ -1302,6 +1302,13 @@ ObjectNode generateContentConfigToMldev(
           "modelArmorConfig parameter is not supported in Gemini API.");
     }
 
+    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/Models.java

@@ -1620,6 +1620,13 @@ ObjectNode generateContentConfigToMldev(
           "modelArmorConfig parameter is not supported in Gemini API.");
     }
 
+    if (Common.getValueByPath(fromObject, new String[] {"serviceTier"}) != null) {
+      Common.setValueByPath(
+          parentObject,
+          new String[] {"serviceTier"},
+          Common.getValueByPath(fromObject, new String[] {"serviceTier"}));
+    }
+
     return toObject;
   }
 
@@ -1864,6 +1871,10 @@ 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.");
+    }
+
     return toObject;
   }
 

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

@@ -239,6 +239,10 @@ 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. */
+  @JsonProperty("serviceTier")
+  public abstract Optional<ServiceTier> serviceTier();
+
   /** Instantiates a builder for GenerateContentConfig. */
   @ExcludeFromGeneratedCoverageReport
   public static Builder builder() {
@@ -1103,6 +1107,44 @@ public Builder clearModelArmorConfig() {
       return modelArmorConfig(Optional.empty());
     }
 
+    /**
+     * Setter for serviceTier.
+     *
+     * <p>serviceTier: The service tier to use for the request. For example, SERVICE_TIER_FLEX.
+     */
+    @JsonProperty("serviceTier")
+    public abstract Builder serviceTier(ServiceTier serviceTier);
+
+    @ExcludeFromGeneratedCoverageReport
+    abstract Builder serviceTier(Optional<ServiceTier> serviceTier);
+
+    /** Clears the value of serviceTier field. */
+    @ExcludeFromGeneratedCoverageReport
+    @CanIgnoreReturnValue
+    public Builder clearServiceTier() {
+      return serviceTier(Optional.empty());
+    }
+
+    /**
+     * Setter for serviceTier given a known enum.
+     *
+     * <p>serviceTier: The service tier to use for the request. For example, SERVICE_TIER_FLEX.
+     */
+    @CanIgnoreReturnValue
+    public Builder serviceTier(ServiceTier.Known knownType) {
+      return serviceTier(new ServiceTier(knownType));
+    }
+
+    /**
+     * Setter for serviceTier given a string.
+     *
+     * <p>serviceTier: The service tier to use for the request. For example, SERVICE_TIER_FLEX.
+     */
+    @CanIgnoreReturnValue
+    public Builder serviceTier(String serviceTier) {
+      return serviceTier(new ServiceTier(serviceTier));
+    }
+
     public abstract GenerateContentConfig build();
   }
 

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

@@ -0,0 +1,114 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Auto-generated code. Do not edit.
+
+package com.google.genai.types;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.google.common.base.Ascii;
+import java.util.Objects;
+
+/** Pricing and performance service tier. */
+public class ServiceTier {
+
+  /** Enum representing the known values for ServiceTier. */
+  public enum Known {
+    /** Default service tier, which is standard. */
+    SERVICE_TIER_UNSPECIFIED,
+
+    /** Flex service tier. */
+    SERVICE_TIER_FLEX,
+
+    /** Standard service tier. */
+    SERVICE_TIER_STANDARD,
+
+    /** Priority service tier. */
+    SERVICE_TIER_PRIORITY
+  }
+
+  private Known serviceTierEnum;
+  private final String value;
+
+  @JsonCreator
+  public ServiceTier(String value) {
+    this.value = value;
+    for (Known serviceTierEnum : Known.values()) {
+      if (Ascii.equalsIgnoreCase(serviceTierEnum.toString(), value)) {
+        this.serviceTierEnum = serviceTierEnum;
+        break;
+      }
+    }
+    if (this.serviceTierEnum == null) {
+      this.serviceTierEnum = Known.SERVICE_TIER_UNSPECIFIED;
+    }
+  }
+
+  public ServiceTier(Known knownValue) {
+    this.serviceTierEnum = knownValue;
+    this.value = knownValue.toString();
+  }
+
+  @ExcludeFromGeneratedCoverageReport
+  @Override
+  @JsonValue
+  public String toString() {
+    return this.value;
+  }
+
+  @ExcludeFromGeneratedCoverageReport
+  @SuppressWarnings("PatternMatchingInstanceof")
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null) {
+      return false;
+    }
+
+    if (!(o instanceof ServiceTier)) {
+      return false;
+    }
+
+    ServiceTier other = (ServiceTier) o;
+
+    if (this.serviceTierEnum != Known.SERVICE_TIER_UNSPECIFIED
+        && other.serviceTierEnum != Known.SERVICE_TIER_UNSPECIFIED) {
+      return this.serviceTierEnum == other.serviceTierEnum;
+    } else if (this.serviceTierEnum == Known.SERVICE_TIER_UNSPECIFIED
+        && other.serviceTierEnum == Known.SERVICE_TIER_UNSPECIFIED) {
+      return this.value.equals(other.value);
+    }
+    return false;
+  }
+
+  @ExcludeFromGeneratedCoverageReport
+  @Override
+  public int hashCode() {
+    if (this.serviceTierEnum != Known.SERVICE_TIER_UNSPECIFIED) {
+      return this.serviceTierEnum.hashCode();
+    } else {
+      return Objects.hashCode(this.value);
+    }
+  }
+
+  @ExcludeFromGeneratedCoverageReport
+  public Known knownEnum() {
+    return this.serviceTierEnum;
+  }
+}