Fix missing content in Anthropic to OpenAI conversion (#17693)

litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py

@@ -613,7 +613,14 @@ class LiteLLMAnthropicMessagesAdapter:
                             )
                         )
 
-            # Handle tool calls
+            # Handle text content
+            if choice.message.content is not None:
+                new_content.append(
+                    AnthropicResponseContentBlockText(
+                        type="text", text=choice.message.content
+                    )
+                )
+            # Handle tool calls (in parallel to text content)
             if (
                 choice.message.tool_calls is not None
                 and len(choice.message.tool_calls) > 0
@@ -642,13 +649,6 @@ class LiteLLMAnthropicMessagesAdapter:
                             provider_specific_fields
                         )
                     new_content.append(tool_use_block)
-            # Handle text content
-            elif choice.message.content is not None:
-                new_content.append(
-                    AnthropicResponseContentBlockText(
-                        type="text", text=choice.message.content
-                    )
-                )
 
         return new_content
 

tests/test_litellm/llms/anthropic/experimental_pass_through/adapters/test_anthropic_experimental_pass_through_adapters_transformation.py

@@ -1,5 +1,6 @@
 import os
 import sys
+from typing import Any, cast
 
 import pytest
 
@@ -20,7 +21,9 @@ from litellm.types.utils import (
     Delta,
     Function,
     Message,
+    ModelResponse,
     StreamingChoices,
+    Usage,
 )
 
 
@@ -341,6 +344,81 @@ def test_translate_openai_content_to_anthropic_empty_function_arguments():
     assert result[0].input == {}, "Empty function arguments should result in empty dict"
 
 
+def test_translate_openai_content_to_anthropic_text_and_tool_calls():
+    """Ensure content blocks contain both the assistant text + tool call data."""
+    openai_choices = [
+        Choices(
+            message=Message(
+                role="assistant",
+                content="Calling get_weather now.",
+                tool_calls=[
+                    ChatCompletionAssistantToolCall(
+                        id="call_weather",
+                        type="function",
+                        function=Function(
+                            name="get_weather",
+                            arguments='{"location": "Boston"}',
+                        ),
+                    )
+                ],
+            )
+        )
+    ]
+
+    adapter = LiteLLMAnthropicMessagesAdapter()
+    result = adapter._translate_openai_content_to_anthropic(choices=openai_choices)
+
+    assert len(result) == 2
+    assert result[0].type == "text"
+    assert result[0].text == "Calling get_weather now."
+    assert result[1].type == "tool_use"
+    assert result[1].id == "call_weather"
+    assert result[1].name == "get_weather"
+    assert result[1].input == {"location": "Boston"}
+
+
+def test_translate_openai_response_to_anthropic_text_and_tool_calls():
+    """`translate_openai_response_to_anthropic` should surface assistant text even when tools fire."""
+    openai_response = ModelResponse(
+        id="resp_text_tool",
+        model="gpt-4o-mini",
+        choices=[
+            Choices(
+                finish_reason="tool_calls",
+                message=Message(
+                    role="assistant",
+                    content="Let me grab the current weather.",
+                    tool_calls=[
+                        ChatCompletionAssistantToolCall(
+                            id="call_tool_combo",
+                            type="function",
+                            function=Function(
+                                name="get_weather", arguments='{"location": "Paris"}'
+                            ),
+                        )
+                    ],
+                ),
+            )
+        ],
+        usage=Usage(prompt_tokens=5, completion_tokens=2),
+    )
+
+    adapter = LiteLLMAnthropicMessagesAdapter()
+    anthropic_response = adapter.translate_openai_response_to_anthropic(
+        response=openai_response
+    )
+
+    anthropic_content = anthropic_response.get("content")
+    assert anthropic_content is not None
+    assert len(anthropic_content) == 2
+    assert cast(Any, anthropic_content[0]).type == "text"
+    assert cast(Any, anthropic_content[0]).text == "Let me grab the current weather."
+    assert cast(Any, anthropic_content[1]).type == "tool_use"
+    assert cast(Any, anthropic_content[1]).id == "call_tool_combo"
+    assert cast(Any, anthropic_content[1]).input == {"location": "Paris"}
+    assert anthropic_response.get("stop_reason") == "tool_use"
+
+
 def test_translate_streaming_openai_chunk_to_anthropic_with_partial_json():
     """Test that partial tool arguments are correctly handled as input_json_delta."""
     choices = [