ADK changes

a2a/src/main/java/com/google/adk/a2a/converters/PartConverter.java

@@ -43,6 +43,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -80,7 +81,13 @@ public static com.google.genai.types.Part toGenaiPart(io.a2a.spec.Part<?> a2aPar
     }
 
     if (a2aPart instanceof TextPart textPart) {
-      return com.google.genai.types.Part.builder().text(textPart.getText()).build();
+      com.google.genai.types.Part.Builder partBuilder =
+          com.google.genai.types.Part.builder().text(textPart.getText());
+      if (textPart.getMetadata() != null
+          && Objects.equals(textPart.getMetadata().get("thought"), Boolean.TRUE)) {
+        partBuilder.thought(true);
+      }
+      return partBuilder.build();
     }
 
     if (a2aPart instanceof FilePart filePart) {

a2a/src/test/java/com/google/adk/a2a/converters/PartConverterTest.java

@@ -43,6 +43,46 @@ public void toGenaiPart_withTextPart_returnsGenaiTextPart() {
     assertThat(result.text()).hasValue("Hello");
   }
 
+  @Test
+  public void toGenaiPart_withTextPartThought_returnsGenaiTextPartWithThought() {
+    TextPart textPart = new TextPart("Thinking process", ImmutableMap.of("thought", true));
+
+    Part result = PartConverter.toGenaiPart(textPart);
+
+    assertThat(result.text()).hasValue("Thinking process");
+    assertThat(result.thought()).hasValue(true);
+  }
+
+  @Test
+  public void toGenaiPart_withTextPartMetadataWithoutThought_returnsGenaiTextPartWithoutThought() {
+    TextPart textPart = new TextPart("Thinking process", ImmutableMap.of("otherKey", "value"));
+
+    Part result = PartConverter.toGenaiPart(textPart);
+
+    assertThat(result.text()).hasValue("Thinking process");
+    assertThat(result.thought()).isEmpty();
+  }
+
+  @Test
+  public void toGenaiPart_withTextPartThoughtFalse_returnsGenaiTextPartWithoutThought() {
+    TextPart textPart = new TextPart("Thinking process", ImmutableMap.of("thought", false));
+
+    Part result = PartConverter.toGenaiPart(textPart);
+
+    assertThat(result.text()).hasValue("Thinking process");
+    assertThat(result.thought()).isEmpty();
+  }
+
+  @Test
+  public void toGenaiPart_withTextPartNonBooleanThought_returnsGenaiTextPartWithoutThought() {
+    TextPart textPart = new TextPart("Thinking process", ImmutableMap.of("thought", "true"));
+
+    Part result = PartConverter.toGenaiPart(textPart);
+
+    assertThat(result.text()).hasValue("Thinking process");
+    assertThat(result.thought()).isEmpty();
+  }
+
   @Test
   public void toGenaiPart_withFilePartUri_returnsGenaiFilePart() {
     FilePart filePart = new FilePart(new FileWithUri("text/plain", "file.txt", "http://file.txt"));