fix: 响应中保留用户请求的原始模型名

- 非流式响应：通过 requested_model 参数传递用户请求的模型名
- 流式响应：StreamState 初始化时使用 ctx.model 而非 ctx.mapped_model
- 流式转换：normalizers 保留初始 model 值，不被上游事件覆盖
- parsed_chunks：格式转换时记录转换后数据，确保与客户端收到的一致

src/api/handlers/base/chat_handler_base.py

@@ -1104,6 +1104,7 @@ class ChatHandlerBase(BaseMessageHandler, ABC):
                     response_json,
                     provider_api_format,
                     client_api_format,
+                    requested_model=model,  # 使用用户请求的原始模型名
                 )
 
             return response_json if isinstance(response_json, dict) else {}

src/api/handlers/base/cli_handler_base.py

@@ -2350,6 +2350,7 @@ class CliMessageHandlerBase(BaseMessageHandler):
                         response_json,
                         provider_api_format,
                         api_format,
+                        requested_model=model,  # 使用用户请求的原始模型名
                     )
                     logger.debug(f"非流式响应格式转换完成: {provider_api_format} -> {api_format}")
                 except Exception as conv_err:

src/api/handlers/base/stream_processor.py

@@ -107,6 +107,8 @@ class StreamProcessor:
         ctx: StreamContext,
         event_name: Optional[str],
         data_str: str,
+        *,
+        skip_record: bool = False,
     ) -> None:
         """
         处理单个 SSE 事件
@@ -117,6 +119,7 @@ class StreamProcessor:
             ctx: 流式上下文
             event_name: 事件名称
             data_str: 事件数据字符串
+            skip_record: 是否跳过记录到 parsed_chunks（当需要格式转换时应为 True）
         """
         if not data_str:
             return
@@ -130,13 +133,13 @@ class StreamProcessor:
         except json.JSONDecodeError:
             return
 
-        ctx.data_count += 1
-
         if not isinstance(data, dict):
             return
 
-        # 收集原始 chunk 数据
+        # 收集原始 chunk 数据（当需要格式转换时跳过，由 _emit_converted_line 记录转换后的数据）
+        if not skip_record:
             ctx.parsed_chunks.append(data)
+            ctx.data_count += 1
 
         # 根据 Provider 格式选择解析器
         parser = self.get_parser_for_provider(ctx)
@@ -557,7 +560,13 @@ class StreamProcessor:
 
                         skip_next_blank_line = True
                         out: list[bytes] = []
+
                         for evt in converted_events:
+                            # 记录转换后的数据到 parsed_chunks（这是客户端实际收到的格式）
+                            if isinstance(evt, dict):
+                                ctx.parsed_chunks.append(evt)
+                                ctx.data_count += 1
+
                             # 统一使用 SSE 格式输出（Gemini streamGenerateContent 也使用 SSE）
                             # 参考: https://ai.google.dev/api/generate-content
                             out.append(
@@ -580,7 +589,8 @@ class StreamProcessor:
                                 line = ""
 
                             if line:
-                                self._process_line(ctx, sse_parser, line)
+                                # 需要格式转换时，跳过记录原始数据（由 _emit_converted_line 记录转换后的数据）
+                                self._process_line(ctx, sse_parser, line, skip_record=True)
                             normalized_line = line.rstrip("\r\n") if line else ""
                             out_chunks = _emit_converted_line(normalized_line)
                             if not out_chunks:
@@ -613,7 +623,8 @@ class StreamProcessor:
                             line = ""
 
                         if line:
-                            self._process_line(ctx, sse_parser, line)
+                            # 需要格式转换时，跳过记录原始数据（由 _emit_converted_line 记录转换后的数据）
+                            self._process_line(ctx, sse_parser, line, skip_record=True)
                         normalized_line = line.rstrip("\r\n") if line else ""
                         out_chunks = _emit_converted_line(normalized_line)
                         if not out_chunks:
@@ -642,7 +653,8 @@ class StreamProcessor:
                         )
                         line = ""
                     if line:
-                        self._process_line(ctx, sse_parser, line)
+                        # 需要格式转换时，跳过记录原始数据
+                        self._process_line(ctx, sse_parser, line, skip_record=True)
                         normalized_line = line.rstrip("\r\n")
                         out_chunks = _emit_converted_line(normalized_line)
                         for out in out_chunks:
@@ -729,6 +741,8 @@ class StreamProcessor:
         ctx: StreamContext,
         sse_parser: SSEEventParser,
         line: str,
+        *,
+        skip_record: bool = False,
     ) -> None:
         """
         处理单行数据
@@ -737,6 +751,7 @@ class StreamProcessor:
             ctx: 流式上下文
             sse_parser: SSE 解析器
             line: 原始行数据
+            skip_record: 是否跳过记录到 parsed_chunks（当需要格式转换时应为 True）
         """
         # SSEEventParser 以"去掉换行符"的单行文本作为输入；这里统一剔除 CR/LF，
         # 避免把空行误判成 "\n" 并导致事件边界解析错误。
@@ -747,7 +762,9 @@ class StreamProcessor:
             ctx.chunk_count += 1
 
         for event in events:
-            self.handle_sse_event(ctx, event.get("event"), event.get("data") or "")
+            self.handle_sse_event(
+                ctx, event.get("event"), event.get("data") or "", skip_record=skip_record
+            )
 
     async def create_monitored_stream(
         self,

src/core/api_format/conversion/normalizer.py

@@ -8,7 +8,7 @@
 from __future__ import annotations
 
 from abc import ABC, abstractmethod
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Optional
 
 from .internal import FormatCapabilities, InternalError, InternalRequest, InternalResponse
 from .stream_events import InternalStreamEvent
@@ -41,8 +41,20 @@ class FormatNormalizer(ABC):
         raise NotImplementedError
 
     @abstractmethod
-    def response_from_internal(self, internal: InternalResponse) -> Dict[str, Any]:
+    def response_from_internal(
-        """将内部表示转换为格式特定响应"""
+        self,
+        internal: InternalResponse,
+        *,
+        requested_model: Optional[str] = None,
+    ) -> Dict[str, Any]:
+        """将内部表示转换为格式特定响应
+
+        Args:
+            internal: 内部响应表示
+            requested_model: 用户请求的原始模型名（可选）。
+                            如果提供，响应中的 model 字段将使用此值，
+                            而不是上游返回的映射后模型名。
+        """
         raise NotImplementedError
 
     # ============ 流式转换（可选） ============

src/core/api_format/conversion/normalizers/claude.py

@@ -241,7 +241,12 @@ class ClaudeNormalizer(FormatNormalizer):
 
         return internal
 
-    def response_from_internal(self, internal: InternalResponse) -> Dict[str, Any]:
+    def response_from_internal(
+        self,
+        internal: InternalResponse,
+        *,
+        requested_model: Optional[str] = None,
+    ) -> Dict[str, Any]:
         cid = internal.id or "unknown"
         if not cid.startswith("msg_"):
             cid = f"msg_{cid}"
@@ -294,11 +299,14 @@ class ClaudeNormalizer(FormatNormalizer):
             if internal.usage.cache_write_tokens:
                 usage["cache_creation_input_tokens"] = int(internal.usage.cache_write_tokens)
 
+        # 优先使用用户请求的原始模型名，回退到上游返回的模型名
+        model_name = requested_model if requested_model else internal.model
+
         return {
             "id": cid,
             "type": "message",
             "role": "assistant",
-            "model": internal.model,
+            "model": model_name,
             "content": content,
             "stop_reason": stop_reason,
             "stop_sequence": None,
@@ -329,9 +337,11 @@ class ClaudeNormalizer(FormatNormalizer):
             message_raw = chunk.get("message")
             message: Dict[str, Any] = message_raw if isinstance(message_raw, dict) else {}
             msg_id = str(message.get("id") or "")
-            model = str(message.get("model") or "")
+            # 保留初始化时设置的 model（客户端请求的模型），仅在空时用上游值
+            model = state.model or str(message.get("model") or "")
             state.message_id = msg_id or state.message_id
-            state.model = model or state.model
+            if not state.model:
+                state.model = model
             ss["message_started"] = True
             ss.setdefault("block_index_to_tool_id", {})
             events.append(MessageStartEvent(message_id=msg_id, model=model))
@@ -440,7 +450,9 @@ class ClaudeNormalizer(FormatNormalizer):
 
         if isinstance(event, MessageStartEvent):
             state.message_id = event.message_id or state.message_id
-            state.model = event.model or state.model
+            # 保留初始化时设置的 model（客户端请求的模型），仅在空时用事件值
+            if not state.model:
+                state.model = event.model or ""
             ss.setdefault("block_index_to_tool_id", {})
             message_obj: Dict[str, Any] = {
                 "id": state.message_id or "msg_stream",

src/core/api_format/conversion/normalizers/gemini.py

@@ -333,7 +333,12 @@ class GeminiNormalizer(FormatNormalizer):
 
         return internal
 
-    def response_from_internal(self, internal: InternalResponse) -> Dict[str, Any]:
+    def response_from_internal(
+        self,
+        internal: InternalResponse,
+        *,
+        requested_model: Optional[str] = None,
+    ) -> Dict[str, Any]:
         parts: List[Dict[str, Any]] = []
         for b in internal.content:
             if isinstance(b, TextBlock):
@@ -386,9 +391,12 @@ class GeminiNormalizer(FormatNormalizer):
         if finish_reason is not None:
             candidate["finishReason"] = finish_reason
 
+        # 优先使用用户请求的原始模型名，回退到上游返回的模型名
+        model_name = requested_model if requested_model else (internal.model or "gemini")
+
         out: Dict[str, Any] = {
             "candidates": [candidate],
-            "modelVersion": internal.model or "gemini",
+            "modelVersion": model_name,
         }
 
         if usage_metadata:
@@ -553,7 +561,9 @@ class GeminiNormalizer(FormatNormalizer):
 
         if isinstance(event, MessageStartEvent):
             state.message_id = event.message_id or state.message_id
-            state.model = event.model or state.model
+            # 保留初始化时设置的 model（客户端请求的模型），仅在空时用事件值
+            if not state.model:
+                state.model = event.model or ""
             ss.setdefault("tool_blocks", {})
             return out
 

src/core/api_format/conversion/normalizers/openai.py

@@ -281,13 +281,20 @@ class OpenAINormalizer(FormatNormalizer):
 
         return internal
 
-    def response_from_internal(self, internal: InternalResponse) -> Dict[str, Any]:
+    def response_from_internal(
+        self,
+        internal: InternalResponse,
+        *,
+        requested_model: Optional[str] = None,
+    ) -> Dict[str, Any]:
         # OpenAI Chat Completions response envelope
+        # 优先使用用户请求的原始模型名，回退到上游返回的模型名
+        model_name = requested_model if requested_model else internal.model
         out: Dict[str, Any] = {
             "id": internal.id or "chatcmpl-unknown",
             "object": "chat.completion",
             "created": int(time.time()),
-            "model": internal.model,
+            "model": model_name,
             "choices": [],
         }
 
@@ -452,7 +459,9 @@ class OpenAINormalizer(FormatNormalizer):
 
         if isinstance(event, MessageStartEvent):
             state.message_id = event.message_id or state.message_id
-            state.model = event.model or state.model
+            # 保留初始化时设置的 model（客户端请求的模型），仅在空时用事件值
+            if not state.model:
+                state.model = event.model or ""
             out.append(base_chunk({"role": "assistant"}))
             return out
 

src/core/api_format/conversion/normalizers/openai_cli.py

@@ -187,7 +187,12 @@ class OpenAICliNormalizer(FormatNormalizer):
             extra=extra,
         )
 
-    def response_from_internal(self, internal: InternalResponse) -> Dict[str, Any]:
+    def response_from_internal(
+        self,
+        internal: InternalResponse,
+        *,
+        requested_model: Optional[str] = None,
+    ) -> Dict[str, Any]:
         text = self._collapse_internal_text(internal.content)
 
         output_message = {
@@ -204,11 +209,14 @@ class OpenAICliNormalizer(FormatNormalizer):
             "total_tokens": usage.total_tokens or (usage.input_tokens + usage.output_tokens),
         }
 
+        # 优先使用用户请求的原始模型名，回退到上游返回的模型名
+        model_name = requested_model if requested_model else (internal.model or "")
+
         return {
             "id": internal.id or "resp",
             "object": "response",
             "created": int(time.time()),
-            "model": internal.model or "",
+            "model": model_name,
             "status": "completed",
             "output": [output_message],
             "usage": usage_obj,
@@ -241,9 +249,11 @@ class OpenAICliNormalizer(FormatNormalizer):
             resp_obj = chunk.get("response")
             resp_obj = resp_obj if isinstance(resp_obj, dict) else {}
             msg_id = str(resp_obj.get("id") or chunk.get("id") or state.message_id or "")
-            model = str(resp_obj.get("model") or chunk.get("model") or state.model or "")
+            # 保留初始化时设置的 model（客户端请求的模型），仅在空时用上游值
+            model = state.model or str(resp_obj.get("model") or chunk.get("model") or "")
             if msg_id or model or etype:
                 state.message_id = msg_id
+                if not state.model:
                     state.model = model
                 ss["message_started"] = True
                 ss.setdefault("text_block_started", False)
@@ -301,11 +311,13 @@ class OpenAICliNormalizer(FormatNormalizer):
         # response.in_progress：状态更新，不产生内容事件
         if etype == "response.in_progress":
             # 更新 state 中的元数据（如果有）
+            # 注意：model 保持初始值（客户端请求的模型），不被上游覆盖
             resp_obj = chunk.get("response")
             if isinstance(resp_obj, dict):
                 if resp_obj.get("id"):
                     state.message_id = str(resp_obj.get("id"))
-                if resp_obj.get("model"):
+                # 仅在 model 为空时才用上游值
+                if not state.model and resp_obj.get("model"):
                     state.model = str(resp_obj.get("model"))
             return []
 
@@ -390,7 +402,9 @@ class OpenAICliNormalizer(FormatNormalizer):
 
         if isinstance(event, MessageStartEvent):
             state.message_id = event.message_id or state.message_id or "resp_stream"
-            state.model = event.model or state.model or ""
+            # 保留初始化时设置的 model（客户端请求的模型），仅在空时用事件值
+            if not state.model:
+                state.model = event.model or ""
             ss.setdefault("collected_text", "")
             out.append(
                 event_block(

src/core/api_format/conversion/registry.py

@@ -88,8 +88,28 @@ class FormatConversionRegistry:
         response: Dict[str, Any],
         source_format: str,
         target_format: str,
+        *,
+        requested_model: Optional[str] = None,
     ) -> Dict[str, Any]:
+        """转换响应格式
+
+        Args:
+            response: 原始响应
+            source_format: 源格式
+            target_format: 目标格式
+            requested_model: 用户请求的原始模型名（可选）。
+                            如果提供，响应中的 model 字段将使用此值，
+                            而不是上游返回的映射后模型名。
+        """
         if str(source_format).upper() == str(target_format).upper():
+            # 即使格式相同，也需要替换 model 字段
+            if requested_model and isinstance(response, dict):
+                response = dict(response)  # 避免修改原始响应
+                # 支持不同格式的 model 字段名
+                if "model" in response:
+                    response["model"] = requested_model
+                elif "modelVersion" in response:
+                    response["modelVersion"] = requested_model
             return response
 
         src = self._require_normalizer(source_format)
@@ -98,7 +118,7 @@ class FormatConversionRegistry:
         with _track_conversion_metrics("response", str(source_format).upper(), str(target_format).upper()):
             try:
                 internal = src.response_to_internal(response)
-                return tgt.response_from_internal(internal)
+                return tgt.response_from_internal(internal, requested_model=requested_model)
             except Exception as e:
                 raise FormatConversionError(source_format, target_format, str(e)) from e
 
@@ -151,6 +171,12 @@ class FormatConversionRegistry:
             )
 
         if state is None:
+            # 调用方应提供预初始化的 state（包含 model/message_id），
+            # 这里仅作为防御性回退，可能导致响应中 model 字段为空
+            logger.debug(
+                f"convert_stream_chunk: state is None, creating empty StreamState "
+                f"(source={source_format}, target={target_format})"
+            )
             state = StreamState()
 
         with _track_conversion_metrics("stream", str(source_format).upper(), str(target_format).upper()):

tests/api/handlers/base/test_cli_handler_convert.py

@@ -54,9 +54,10 @@ class MockCliHandler:
             return [line]
 
         # 初始化流式转换状态
+        # 使用客户端请求的模型名（ctx.model），而非映射后的模型名（ctx.mapped_model）
         if ctx.stream_conversion_state is None:
             ctx.stream_conversion_state = StreamState(
-                model=ctx.mapped_model or ctx.model,
+                model=ctx.model,
                 message_id=ctx.response_id or ctx.request_id,
             )
 
@@ -143,12 +144,16 @@ class TestConvertSseLineWithMockConverter:
         assert json.loads(result[0][6:]) == chunk
 
     def test_state_initialization(self) -> None:
-        """测试状态自动初始化"""
+        """测试状态自动初始化
+        
+        流式转换状态应使用用户请求的原始模型名（ctx.model），
+        而非映射后的模型名（ctx.mapped_model），确保返回给客户端的响应使用原始模型名。
+        """
         handler = MockCliHandler()
         ctx = StreamContext(model="gpt-4", api_format="OPENAI")
         ctx.provider_api_format = "OPENAI"
         ctx.client_api_format = "OPENAI"
-        ctx.mapped_model = "claude-3-5-sonnet"
+        ctx.mapped_model = "claude-3-5-sonnet"  # 映射后的模型名（发给上游的）
         ctx.request_id = "req_123"
 
         chunk = {"choices": [{"delta": {"content": "test"}}]}
@@ -156,9 +161,9 @@ class TestConvertSseLineWithMockConverter:
 
         handler._convert_sse_line(ctx, line, [])
 
-        # 验证状态已初始化
+        # 验证状态已初始化，使用用户请求的原始模型名
         assert ctx.stream_conversion_state is not None
-        assert ctx.stream_conversion_state.model == "claude-3-5-sonnet"
+        assert ctx.stream_conversion_state.model == "gpt-4"  # 应使用原始模型名，非 mapped_model
         assert ctx.stream_conversion_state.message_id == "req_123"