feat: add transcription fields mapping

core/src/main/java/com/google/adk/events/Event.java

@@ -33,6 +33,7 @@
 import com.google.genai.types.FunctionResponse;
 import com.google.genai.types.GenerateContentResponseUsageMetadata;
 import com.google.genai.types.GroundingMetadata;
+import com.google.genai.types.Transcription;
 import java.time.Instant;
 import java.util.List;
 import java.util.Objects;
@@ -42,6 +43,7 @@
 import org.jspecify.annotations.Nullable;
 
 // TODO - b/413761119 update Agent.java when resolved.
+
 /** Represents an event in a session. */
 @JsonDeserialize(builder = Event.Builder.class)
 public class Event extends JsonBaseModel {
@@ -64,6 +66,9 @@ public class Event extends JsonBaseModel {
   private @Nullable GroundingMetadata groundingMetadata;
   private @Nullable List<CustomMetadata> customMetadata;
   private @Nullable String modelVersion;
+  private @Nullable Transcription inputTranscription;
+  private @Nullable Transcription outputTranscription;
+
   private long timestamp;
 
   private Event() {}
@@ -266,6 +271,32 @@ public void setModelVersion(@Nullable String modelVersion) {
     this.modelVersion = modelVersion;
   }
 
+  /**
+   * Input transcription. The transcription is independent to the model turn which means it doesn’t
+   * imply any ordering between transcription and model turn.
+   */
+  @JsonProperty("inputTranscription")
+  public Optional<Transcription> inputTranscription() {
+    return Optional.ofNullable(inputTranscription);
+  }
+
+  public void setInputTranscription(@Nullable Transcription inputTranscription) {
+    this.inputTranscription = inputTranscription;
+  }
+
+  /**
+   * Output transcription. The transcription is independent to the model turn which means it doesn’t
+   * imply any ordering between transcription and model turn.
+   */
+  @JsonProperty("outputTranscription")
+  public Optional<Transcription> outputTranscription() {
+    return Optional.ofNullable(outputTranscription);
+  }
+
+  public void setOutputTranscription(@Nullable Transcription outputTranscription) {
+    this.outputTranscription = outputTranscription;
+  }
+
   /** The timestamp of the event. */
   @JsonProperty("timestamp")
   public long timestamp() {
@@ -362,6 +393,8 @@ public static class Builder {
     private @Nullable GroundingMetadata groundingMetadata;
     private @Nullable List<CustomMetadata> customMetadata;
     private @Nullable String modelVersion;
+    private @Nullable Transcription inputTranscription;
+    private @Nullable Transcription outputTranscription;
     private @Nullable Long timestamp;
 
     @JsonCreator
@@ -520,6 +553,20 @@ public Builder modelVersion(@Nullable String value) {
       return this;
     }
 
+    @CanIgnoreReturnValue
+    @JsonProperty("inputTranscription")
+    public Builder inputTranscription(@Nullable Transcription value) {
+      this.inputTranscription = value;
+      return this;
+    }
+
+    @CanIgnoreReturnValue
+    @JsonProperty("outputTranscription")
+    public Builder outputTranscription(@Nullable Transcription value) {
+      this.outputTranscription = value;
+      return this;
+    }
+
     public Event build() {
       Event event = new Event();
       event.setId(id);
@@ -541,6 +588,8 @@ public Event build() {
       event.setModelVersion(modelVersion);
       event.setActions(actions().orElseGet(() -> EventActions.builder().build()));
       event.setTimestamp(timestamp().orElseGet(() -> Instant.now().toEpochMilli()));
+      event.setInputTranscription(inputTranscription);
+      event.setOutputTranscription(outputTranscription);
       return event;
     }
   }
@@ -575,7 +624,9 @@ public Builder toBuilder() {
             .branch(this.branch)
             .groundingMetadata(this.groundingMetadata)
             .customMetadata(this.customMetadata)
-            .modelVersion(this.modelVersion);
+            .modelVersion(this.modelVersion)
+            .inputTranscription(this.inputTranscription)
+            .outputTranscription(this.outputTranscription);
     if (this.timestamp != 0) {
       builder.timestamp(this.timestamp);
     }
@@ -608,7 +659,9 @@ public boolean equals(Object obj) {
         && Objects.equals(branch, other.branch)
         && Objects.equals(groundingMetadata, other.groundingMetadata)
         && Objects.equals(customMetadata, other.customMetadata)
-        && Objects.equals(modelVersion, other.modelVersion);
+        && Objects.equals(modelVersion, other.modelVersion)
+        && Objects.equals(inputTranscription, other.inputTranscription)
+        && Objects.equals(outputTranscription, other.outputTranscription);
   }
 
   @Override
@@ -637,6 +690,8 @@ public int hashCode() {
         groundingMetadata,
         customMetadata,
         modelVersion,
+        inputTranscription,
+        outputTranscription,
         timestamp);
   }
 }

core/src/main/java/com/google/adk/flows/llmflows/BaseLlmFlow.java

@@ -677,7 +677,9 @@ private Flowable<Event> buildPostprocessingEvents(
         && updatedResponse.errorCode().isEmpty()
         && !updatedResponse.interrupted().orElse(false)
         && !updatedResponse.turnComplete().orElse(false)
-        && updatedResponse.usageMetadata().isEmpty()) {
+        && updatedResponse.usageMetadata().isEmpty()
+        && updatedResponse.inputTranscription().isEmpty()
+        && updatedResponse.outputTranscription().isEmpty()) {
       return processorEvents;
     }
 
@@ -740,7 +742,9 @@ private Event buildModelResponseEvent(
             .avgLogprobs(llmResponse.avgLogprobs().orElse(null))
             .finishReason(llmResponse.finishReason().orElse(null))
             .usageMetadata(llmResponse.usageMetadata().orElse(null))
-            .modelVersion(llmResponse.modelVersion().orElse(null));
+            .modelVersion(llmResponse.modelVersion().orElse(null))
+            .inputTranscription(llmResponse.inputTranscription().orElse(null))
+            .outputTranscription(llmResponse.outputTranscription().orElse(null));
 
     Event event = eventBuilder.build();
 

core/src/main/java/com/google/adk/models/GeminiLlmConnection.java

@@ -192,6 +192,8 @@ private static LlmResponse createServerContentResponse(LiveServerContent serverC
         .partial(serverContent.turnComplete().map(completed -> !completed).orElse(false))
         .turnComplete(serverContent.turnComplete().orElse(false))
         .interrupted(serverContent.interrupted().orElse(null))
+        .inputTranscription(serverContent.inputTranscription().orElse(null))
+        .outputTranscription(serverContent.outputTranscription().orElse(null))
         .build();
   }
 

core/src/main/java/com/google/adk/models/LlmResponse.java

@@ -31,6 +31,7 @@
 import com.google.genai.types.GenerateContentResponsePromptFeedback;
 import com.google.genai.types.GenerateContentResponseUsageMetadata;
 import com.google.genai.types.GroundingMetadata;
+import com.google.genai.types.Transcription;
 import java.util.List;
 import java.util.Optional;
 import org.jspecify.annotations.Nullable;
@@ -115,6 +116,20 @@ public abstract class LlmResponse extends JsonBaseModel {
   @JsonProperty("modelVersion")
   public abstract Optional<String> modelVersion();
 
+  /**
+   * Input transcription. The transcription is independent to the model turn which means it doesn’t
+   * imply any ordering between transcription and model turn.
+   */
+  @JsonProperty("inputTranscription")
+  public abstract Optional<Transcription> inputTranscription();
+
+  /**
+   * Output transcription. The transcription is independent to the model turn which means it doesn’t
+   * imply any ordering between transcription and model turn.
+   */
+  @JsonProperty("outputTranscription")
+  public abstract Optional<Transcription> outputTranscription();
+
   public abstract Builder toBuilder();
 
   /** Builder for constructing {@link LlmResponse} instances. */
@@ -164,6 +179,12 @@ public abstract Builder usageMetadata(
     @JsonProperty("modelVersion")
     public abstract Builder modelVersion(@Nullable String modelVersion);
 
+    @JsonProperty("inputTranscription")
+    public abstract Builder inputTranscription(@Nullable Transcription inputTranscription);
+
+    @JsonProperty("outputTranscription")
+    public abstract Builder outputTranscription(@Nullable Transcription outputTranscription);
+
     @CanIgnoreReturnValue
     public final Builder response(GenerateContentResponse response) {
       Optional<List<Candidate>> candidatesOpt = response.candidates();

core/src/test/java/com/google/adk/events/EventTest.java

@@ -26,6 +26,7 @@
 import com.google.genai.types.FunctionCall;
 import com.google.genai.types.GenerateContentResponseUsageMetadata;
 import com.google.genai.types.Part;
+import com.google.genai.types.Transcription;
 import java.time.Instant;
 import java.util.concurrent.ConcurrentHashMap;
 import org.junit.Test;
@@ -192,6 +193,81 @@ public void event_json_serialization_works() throws Exception {
     assertThat(deserializedEvent).isEqualTo(EVENT);
   }
 
+  @Test
+  public void event_builder_with_transcriptions_works() {
+    Transcription inputTranscription =
+        Transcription.builder().text("user said hello").finished(true).build();
+    Transcription outputTranscription =
+        Transcription.builder().text("model said hi").finished(false).build();
+    Event event =
+        Event.builder()
+            .id("event_id")
+            .invocationId("invocation_id")
+            .author("agent")
+            .timestamp(123456789L)
+            .inputTranscription(inputTranscription)
+            .outputTranscription(outputTranscription)
+            .build();
+
+    assertThat(event.inputTranscription()).hasValue(inputTranscription);
+    assertThat(event.outputTranscription()).hasValue(outputTranscription);
+  }
+
+  @Test
+  public void event_transcriptions_empty_by_default() {
+    Event event =
+        Event.builder().id("event_id").invocationId("invocation_id").author("agent").build();
+
+    assertThat(event.inputTranscription()).isEmpty();
+    assertThat(event.outputTranscription()).isEmpty();
+  }
+
+  @Test
+  public void event_equals_differentiates_transcriptions() {
+    Transcription transcription = Transcription.builder().text("hello").finished(true).build();
+    Event eventWithTranscription =
+        Event.builder()
+            .id("event_id")
+            .invocationId("invocation_id")
+            .author("agent")
+            .timestamp(123456789L)
+            .inputTranscription(transcription)
+            .build();
+    Event eventWithoutTranscription =
+        Event.builder()
+            .id("event_id")
+            .invocationId("invocation_id")
+            .author("agent")
+            .timestamp(123456789L)
+            .build();
+
+    assertThat(eventWithTranscription).isNotEqualTo(eventWithoutTranscription);
+  }
+
+  @Test
+  public void event_json_serialization_with_transcriptions_works() throws Exception {
+    Transcription inputTranscription =
+        Transcription.builder().text("user said hello").finished(true).build();
+    Transcription outputTranscription =
+        Transcription.builder().text("model said hi").finished(false).build();
+    Event event =
+        Event.builder()
+            .id("event_id")
+            .invocationId("invocation_id")
+            .author("agent")
+            .timestamp(123456789L)
+            .inputTranscription(inputTranscription)
+            .outputTranscription(outputTranscription)
+            .build();
+
+    String json = event.toJson();
+    Event deserialized = Event.fromJson(json);
+
+    assertThat(deserialized).isEqualTo(event);
+    assertThat(deserialized.inputTranscription()).hasValue(inputTranscription);
+    assertThat(deserialized.outputTranscription()).hasValue(outputTranscription);
+  }
+
   @Test
   public void finalResponse_returnsTrueIfNoToolCalls() {
     Event event =

core/src/test/java/com/google/adk/flows/llmflows/BaseLlmFlowTest.java

@@ -43,6 +43,7 @@
 import com.google.genai.types.FunctionDeclaration;
 import com.google.genai.types.GenerateContentResponseUsageMetadata;
 import com.google.genai.types.Part;
+import com.google.genai.types.Transcription;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.ContextKey;
 import io.opentelemetry.context.Scope;
@@ -641,6 +642,94 @@ public void run_contextPropagation() {
     assertThat(events.get(0).content()).hasValue(content);
   }
 
+  @Test
+  public void postprocess_onlyInputTranscription_returnsEvent() {
+    Transcription inputTranscription =
+        Transcription.builder().text("user said hello").finished(true).build();
+    LlmResponse llmResponse = LlmResponse.builder().inputTranscription(inputTranscription).build();
+    InvocationContext invocationContext =
+        createInvocationContext(createTestAgent(createTestLlm(llmResponse)));
+    BaseLlmFlow baseLlmFlow = createBaseLlmFlowWithoutProcessors();
+    Event baseEvent =
+        Event.builder()
+            .invocationId(invocationContext.invocationId())
+            .author(invocationContext.agent().name())
+            .build();
+
+    List<Event> events =
+        baseLlmFlow
+            .postprocess(
+                invocationContext,
+                baseEvent,
+                LlmRequest.builder().build(),
+                llmResponse,
+                Context.current())
+            .toList()
+            .blockingGet();
+
+    assertThat(events).hasSize(1);
+    Event event = getOnlyElement(events);
+    assertThat(event.inputTranscription()).hasValue(inputTranscription);
+    assertThat(event.outputTranscription()).isEmpty();
+  }
+
+  @Test
+  public void postprocess_onlyOutputTranscription_returnsEvent() {
+    Transcription outputTranscription =
+        Transcription.builder().text("model replied hi").finished(false).build();
+    LlmResponse llmResponse =
+        LlmResponse.builder().outputTranscription(outputTranscription).build();
+    InvocationContext invocationContext =
+        createInvocationContext(createTestAgent(createTestLlm(llmResponse)));
+    BaseLlmFlow baseLlmFlow = createBaseLlmFlowWithoutProcessors();
+    Event baseEvent =
+        Event.builder()
+            .invocationId(invocationContext.invocationId())
+            .author(invocationContext.agent().name())
+            .build();
+
+    List<Event> events =
+        baseLlmFlow
+            .postprocess(
+                invocationContext,
+                baseEvent,
+                LlmRequest.builder().build(),
+                llmResponse,
+                Context.current())
+            .toList()
+            .blockingGet();
+
+    assertThat(events).hasSize(1);
+    Event event = getOnlyElement(events);
+    assertThat(event.outputTranscription()).hasValue(outputTranscription);
+    assertThat(event.inputTranscription()).isEmpty();
+  }
+
+  @Test
+  public void run_responseWithTranscriptions_propagatesTranscriptionsToEvent() {
+    Transcription inputTranscription =
+        Transcription.builder().text("user said hello").finished(true).build();
+    Transcription outputTranscription =
+        Transcription.builder().text("model replied hi").finished(true).build();
+    Content content = Content.fromParts(Part.fromText("model replied hi"));
+    LlmResponse llmResponse =
+        LlmResponse.builder()
+            .content(content)
+            .inputTranscription(inputTranscription)
+            .outputTranscription(outputTranscription)
+            .build();
+    TestLlm testLlm = createTestLlm(llmResponse);
+    InvocationContext invocationContext = createInvocationContext(createTestAgent(testLlm));
+    BaseLlmFlow baseLlmFlow = createBaseLlmFlowWithoutProcessors();
+
+    List<Event> events = baseLlmFlow.run(invocationContext).toList().blockingGet();
+
+    assertThat(events).hasSize(1);
+    Event event = getOnlyElement(events);
+    assertThat(event.inputTranscription()).hasValue(inputTranscription);
+    assertThat(event.outputTranscription()).hasValue(outputTranscription);
+  }
+
   @Test
   public void postprocess_noResponseProcessors_onlyUsageMetadata_returnsEvent() {
     GenerateContentResponseUsageMetadata usageMetadata =