Fix empty tool_call_id in Anthropic messages API tool result conversion (#34745)

Signed-off-by: <>
Signed-off-by: sfeng33 <4florafeng@gmail.com>
Co-authored-by: Flora Feng <sfeng33@h100-01.nemg-001.lab.rdu2.dc.redhat.com>
Co-authored-by: Nicolò Lucchesi <nlucches@redhat.com>

vllm/entrypoints/anthropic/protocol.py

@@ -40,6 +40,7 @@ class AnthropicContentBlock(BaseModel):
     source: dict[str, Any] | None = None
     # For tool use/result
     id: str | None = None
+    tool_use_id: str | None = None
     name: str | None = None
     input: dict[str, Any] | None = None
     content: str | list[dict[str, Any]] | None = None

vllm/entrypoints/anthropic/serving.py

@@ -139,7 +139,7 @@ class AnthropicServingMessages(OpenAIServingChat):
                             openai_messages.append(
                                 {
                                     "role": "tool",
-                                    "tool_call_id": block.id or "",
+                                    "tool_call_id": block.tool_use_id or "",
                                     "content": str(block.content)
                                     if block.content
                                     else "",