fix(anthropic): allow images in user messages while filtering model turns

src/google/adk/models/anthropic_llm.py

@@ -142,7 +142,7 @@ def content_to_message_param(
   message_block = []
   for part in content.parts or []:
     # Image data is not supported in Claude for model turns.
-    if _is_image_part(part):
+    if content.role != "user" and _is_image_part(part):
       logger.warning("Image data is not supported in Claude for model turns.")
       continue
 

tests/unittests/models/test_anthropic_llm.py

@@ -20,6 +20,7 @@
 from google.adk import version as adk_version
 from google.adk.models import anthropic_llm
 from google.adk.models.anthropic_llm import Claude
+from google.adk.models.anthropic_llm import content_to_message_param
 from google.adk.models.anthropic_llm import function_declaration_to_tool_param
 from google.adk.models.llm_request import LlmRequest
 from google.adk.models.llm_response import LlmResponse
@@ -346,3 +347,81 @@ async def mock_coro():
       mock_client.messages.create.assert_called_once()
       _, kwargs = mock_client.messages.create.call_args
       assert kwargs["max_tokens"] == 4096
+
+
+content_to_message_param_test_cases = [
+    (
+        "user_role_with_text_and_image",
+        Content(
+            role="user",
+            parts=[
+                Part.from_text(text="What's in this image?"),
+                Part(
+                    inline_data=types.Blob(
+                        mime_type="image/jpeg", data=b"fake_image_data"
+                    )
+                ),
+            ],
+        ),
+        "user",
+        2,  # Expected content length
+        False,  # Should not log warning
+    ),
+    (
+        "model_role_with_text_and_image",
+        Content(
+            role="model",
+            parts=[
+                Part.from_text(text="I see a cat."),
+                Part(
+                    inline_data=types.Blob(
+                        mime_type="image/png", data=b"fake_image_data"
+                    )
+                ),
+            ],
+        ),
+        "assistant",
+        1,  # Image filtered out, only text remains
+        True,  # Should log warning
+    ),
+    (
+        "assistant_role_with_text_and_image",
+        Content(
+            role="assistant",
+            parts=[
+                Part.from_text(text="Here's what I found."),
+                Part(
+                    inline_data=types.Blob(
+                        mime_type="image/webp", data=b"fake_image_data"
+                    )
+                ),
+            ],
+        ),
+        "assistant",
+        1,  # Image filtered out, only text remains
+        True,  # Should log warning
+    ),
+]
+
+
+@pytest.mark.parametrize(
+    "_, content, expected_role, expected_content_length, should_log_warning",
+    content_to_message_param_test_cases,
+    ids=[case[0] for case in content_to_message_param_test_cases],
+)
+def test_content_to_message_param_with_images(
+    _, content, expected_role, expected_content_length, should_log_warning
+):
+  """Test content_to_message_param handles images correctly based on role."""
+  with mock.patch("google.adk.models.anthropic_llm.logger") as mock_logger:
+    result = content_to_message_param(content)
+
+    assert result["role"] == expected_role
+    assert len(result["content"]) == expected_content_length
+
+    if should_log_warning:
+      mock_logger.warning.assert_called_once_with(
+          "Image data is not supported in Claude for model turns."
+      )
+    else:
+      mock_logger.warning.assert_not_called()