Fix: Resolve issue #5814 by adjusting function call prompt order in messages

python/sglang/srt/openai_api/adapter.py

@@ -948,32 +948,6 @@ def v1_chat_generate_request(
 
             if chat_template_name is None:
                 openai_compatible_messages = []
-                if (
-                    tools
-                    and tokenizer_manager.server_args.tool_call_parser == "deepseekv3"
-                ):
-                    # add function call prompt to deepseekv3
-                    openai_compatible_messages.append(
-                        {
-                            "role": "system",
-                            "content": """You are a helpful Assistant.
-                    ## Tools
-                    ### Function
-                    You have the following functions available:
-                    """
-                            + "".join(
-                                [
-                                    f"""
-                        - `{tool['name']}`:
-                        ```json
-                        {json.dumps(tool)}
-                        ```
-                        """
-                                    for tool in tools
-                                ]
-                            ),
-                        }
-                    )
 
                 for message in request.messages:
                     if message.content is None:
@@ -989,6 +963,37 @@ def v1_chat_generate_request(
                                 openai_compatible_messages.append(
                                     {"role": message.role, "content": content["text"]}
                                 )
+                if (
+                    tools
+                    and tokenizer_manager.server_args.tool_call_parser == "deepseekv3"
+                ):
+                    tool_content = """You are a helpful Assistant.
+                    ## Tools
+                    ### Function
+                    You have the following functions available:
+                    """ + "".join(
+                        [
+                            f"""
+                        - `{tool['name']}`:
+                        ```json
+                        {json.dumps(tool)}
+                        ```
+                        """
+                            for tool in tools
+                        ]
+                    )
+                    system_messages = [
+                        msg
+                        for msg in openai_compatible_messages
+                        if msg["role"] == "system"
+                    ]
+
+                    if system_messages:
+                        system_messages[-1]["content"] += "\n" + tool_content
+                    else:
+                        openai_compatible_messages.insert(
+                            0, {"role": "system", "content": tool_content}
+                        )
                 if (
                     openai_compatible_messages
                     and openai_compatible_messages[-1]["role"] == "assistant"