feat: add reasoning_effort configuration support for Doubao/GPT-5 models (#947)

* feat: Add reasoning effort configuration support

* Add `reasoning_effort` parameter to model config and agent initialization
* Support reasoning effort levels (minimal/low/medium/high) for Doubao/GPT-5 models
* Add UI controls in input box for reasoning effort selection
* Update doubao-seed-1.8 example config with reasoning effort support

Fixes & Cleanup:
* Ensure UTF-8 encoding for file operations
* Remove unused imports

* fix: set reasoning_effort to None for unsupported models

* fix: unit test error

* Update frontend/src/components/workspace/input-box.tsx

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

.gitignore

@@ -28,6 +28,7 @@ extensions_config.json
 
 # IDE
 .idea/
+.vscode/
 
 # Coverage report
 coverage.xml

backend/src/agents/lead_agent/agent.py

@@ -256,6 +256,7 @@ def make_lead_agent(config: RunnableConfig):
     from src.tools import get_available_tools
 
     thinking_enabled = config.get("configurable", {}).get("thinking_enabled", True)
+    reasoning_effort = config.get("configurable", {}).get("reasoning_effort", None)
     requested_model_name = config.get("configurable", {}).get("model_name") or config.get("configurable", {}).get("model")
     model_name = _resolve_model_name(requested_model_name)
     if model_name is None:
@@ -274,8 +275,9 @@ def make_lead_agent(config: RunnableConfig):
         thinking_enabled = False
 
     logger.info(
-        "thinking_enabled: %s, model_name: %s, is_plan_mode: %s, subagent_enabled: %s, max_concurrent_subagents: %s",
+        "thinking_enabled: %s, reasoning_effort: %s, model_name: %s, is_plan_mode: %s, subagent_enabled: %s, max_concurrent_subagents: %s",
         thinking_enabled,
+        reasoning_effort,
         model_name,
         is_plan_mode,
         subagent_enabled,
@@ -289,13 +291,14 @@ def make_lead_agent(config: RunnableConfig):
         {
             "model_name": model_name or "default",
             "thinking_enabled": thinking_enabled,
+            "reasoning_effort": reasoning_effort,
             "is_plan_mode": is_plan_mode,
             "subagent_enabled": subagent_enabled,
         }
     )
 
     return create_agent(
-        model=create_chat_model(name=model_name, thinking_enabled=thinking_enabled),
+        model=create_chat_model(name=model_name, thinking_enabled=thinking_enabled, reasoning_effort=reasoning_effort),
         tools=get_available_tools(model_name=model_name, subagent_enabled=subagent_enabled),
         middleware=_build_middlewares(config, model_name=model_name),
         system_prompt=apply_prompt_template(subagent_enabled=subagent_enabled, max_concurrent_subagents=max_concurrent_subagents),

backend/src/client.py

@@ -400,6 +400,7 @@ class DeerFlowClient:
                     "display_name": getattr(model, "display_name", None),
                     "description": getattr(model, "description", None),
                     "supports_thinking": getattr(model, "supports_thinking", False),
+                    "supports_reasoning_effort": getattr(model, "supports_reasoning_effort", False),
                 }
                 for model in self._app_config.models
             ]
@@ -458,6 +459,7 @@ class DeerFlowClient:
             "display_name": getattr(model, "display_name", None),
             "description": getattr(model, "description", None),
             "supports_thinking": getattr(model, "supports_thinking", False),
+            "supports_reasoning_effort": getattr(model, "supports_reasoning_effort", False),
         }
 
     # ------------------------------------------------------------------

backend/src/config/app_config.py

@@ -72,7 +72,7 @@ class AppConfig(BaseModel):
             AppConfig: The loaded config.
         """
         resolved_path = cls.resolve_config_path(config_path)
-        with open(resolved_path) as f:
+        with open(resolved_path, encoding="utf-8") as f:
             config_data = yaml.safe_load(f)
         config_data = cls.resolve_env_variables(config_data)
 

backend/src/config/extensions_config.py

@@ -133,7 +133,7 @@ class ExtensionsConfig(BaseModel):
             # Return empty config if extensions config file is not found
             return cls(mcp_servers={}, skills={})
 
-        with open(resolved_path) as f:
+        with open(resolved_path, encoding="utf-8") as f:
             config_data = json.load(f)
 
         cls.resolve_env_variables(config_data)

backend/src/config/model_config.py

@@ -14,6 +14,7 @@ class ModelConfig(BaseModel):
     model: str = Field(..., description="Model name")
     model_config = ConfigDict(extra="allow")
     supports_thinking: bool = Field(default_factory=lambda: False, description="Whether the model supports thinking")
+    supports_reasoning_effort: bool = Field(default_factory=lambda: False, description="Whether the model supports reasoning effort")
     when_thinking_enabled: dict | None = Field(
         default_factory=lambda: None,
         description="Extra settings to be passed to the model when thinking is enabled",

backend/src/gateway/routers/models.py

@@ -13,6 +13,7 @@ class ModelResponse(BaseModel):
     display_name: str | None = Field(None, description="Human-readable name")
     description: str | None = Field(None, description="Model description")
     supports_thinking: bool = Field(default=False, description="Whether model supports thinking mode")
+    supports_reasoning_effort: bool = Field(default=False, description="Whether model supports reasoning effort")
 
 
 class ModelsListResponse(BaseModel):
@@ -63,6 +64,7 @@ async def list_models() -> ModelsListResponse:
             display_name=model.display_name,
             description=model.description,
             supports_thinking=model.supports_thinking,
+            supports_reasoning_effort=model.supports_reasoning_effort,
         )
         for model in config.models
     ]
@@ -107,4 +109,5 @@ async def get_model(model_name: str) -> ModelResponse:
         display_name=model.display_name,
         description=model.description,
         supports_thinking=model.supports_thinking,
+        supports_reasoning_effort=model.supports_reasoning_effort,
     )

backend/src/models/factory.py

@@ -32,6 +32,7 @@ def create_chat_model(name: str | None = None, thinking_enabled: bool = False, *
             "display_name",
             "description",
             "supports_thinking",
+            "supports_reasoning_effort",
             "when_thinking_enabled",
             "supports_vision",
         },
@@ -40,6 +41,11 @@ def create_chat_model(name: str | None = None, thinking_enabled: bool = False, *
         if not model_config.supports_thinking:
             raise ValueError(f"Model {name} does not support thinking. Set `supports_thinking` to true in the `config.yaml` to enable thinking.") from None
         model_settings_from_config.update(model_config.when_thinking_enabled)
+    if not thinking_enabled and model_config.when_thinking_enabled and model_config.when_thinking_enabled.get("extra_body", {}).get("thinking", {}).get("type"):
+        kwargs.update({"extra_body": {"thinking": {"type": "disabled"}}})
+        kwargs.update({"reasoning_effort": "minimal"})
+    if not model_config.supports_reasoning_effort:
+        kwargs.update({"reasoning_effort": None})
     model_instance = model_class(**kwargs, **model_settings_from_config)
 
     if is_tracing_enabled():

backend/src/reflection/resolvers.py

@@ -1,7 +1,4 @@
 from importlib import import_module
-from typing import TypeVar
-
-T = TypeVar("T")
 
 
 def resolve_variable[T](

backend/tests/test_client.py

@@ -25,6 +25,8 @@ def mock_app_config():
     """Provide a minimal AppConfig mock."""
     model = MagicMock()
     model.name = "test-model"
+    model.supports_thinking = False
+    model.supports_reasoning_effort = False
     model.model_dump.return_value = {"name": "test-model", "use": "langchain_openai:ChatOpenAI"}
 
     config = MagicMock()
@@ -379,6 +381,7 @@ class TestGetModel:
         model_cfg.display_name = "Test Model"
         model_cfg.description = "A test model"
         model_cfg.supports_thinking = True
+        model_cfg.supports_reasoning_effort = True
         client._app_config.get_model_config.return_value = model_cfg
 
         result = client.get_model("test-model")
@@ -387,6 +390,7 @@ class TestGetModel:
             "display_name": "Test Model",
             "description": "A test model",
             "supports_thinking": True,
+            "supports_reasoning_effort": True,
         }
 
     def test_not_found(self, client):
@@ -928,6 +932,7 @@ class TestScenarioConfigManagement:
         model_cfg.display_name = None
         model_cfg.description = None
         model_cfg.supports_thinking = False
+        model_cfg.supports_reasoning_effort = False
         client._app_config.get_model_config.return_value = model_cfg
         detail = client.get_model(model_name)
         assert detail["name"] == model_name

backend/tests/test_lead_agent_model_resolution.py

@@ -84,9 +84,10 @@ def test_make_lead_agent_disables_thinking_when_model_does_not_support_it(monkey
 
     captured: dict[str, object] = {}
 
-    def _fake_create_chat_model(*, name, thinking_enabled):
+    def _fake_create_chat_model(*, name, thinking_enabled, reasoning_effort=None):
         captured["name"] = name
         captured["thinking_enabled"] = thinking_enabled
+        captured["reasoning_effort"] = reasoning_effort
         return object()
 
     monkeypatch.setattr(lead_agent_module, "create_chat_model", _fake_create_chat_model)

config.example.yaml

@@ -65,18 +65,19 @@ models:
   #         type: enabled
 
   # Example: Volcengine (Doubao) model
-  # - name: doubao-seed-1.8
+  - name: doubao-seed-1.8
-  #   display_name: Doubao 1.8 (Thinking)
+    display_name: Doubao-Seed-1.8
-  #   use: langchain_deepseek:ChatDeepSeek
+    use: src.models.patched_deepseek:PatchedChatDeepSeek
-  #   model: ep-m-20260106111913-xxxxx
+    model: doubao-seed-1-8-251228
-  #   api_base: https://ark.cn-beijing.volces.com/api/v3
+    api_base: https://ark.cn-beijing.volces.com/api/v3
-  #   api_key: $VOLCENGINE_API_KEY
+    api_key: $VOLCENGINE_API_KEY
-  #   supports_thinking: true
+    supports_thinking: true
-  #   supports_vision: false  # Check your specific model's capabilities
+    supports_vision: true
-  #   when_thinking_enabled:
+    supports_reasoning_effort: true
-  #     extra_body:
+    when_thinking_enabled:
-  #       thinking:
+      extra_body:
-  #         type: enabled
+        thinking:
+          type: enabled
 
   # Example: Kimi K2.5 model
   # - name: kimi-k2.5

frontend/src/app/workspace/chats/[thread_id]/page.tsx

@@ -177,6 +177,7 @@ export default function ChatPage() {
       is_plan_mode:
         settings.context.mode === "pro" || settings.context.mode === "ultra",
       subagent_enabled: settings.context.mode === "ultra",
+      reasoning_effort: settings.context.reasoning_effort,
     },
     afterSubmit() {
       router.push(pathOfThread(threadId!));
@@ -236,10 +237,9 @@ export default function ChatPage() {
                   className={cn("size-full", !isNewThread && "pt-10")}
                   threadId={threadId}
                   thread={thread}
-                  messagesOverride={
+                  messages={
-                    !thread.isLoading && finalState?.messages
+                    (finalState?.messages as Message[])
-                      ? (finalState.messages as Message[])
+                      ?? thread.messages
-                      : undefined
                   }
                   paddingBottom={todoListCollapsed ? 160 : 280}
                 />

frontend/src/components/workspace/input-box.tsx

@@ -106,6 +106,7 @@ export function InputBox({
     "thread_id" | "is_plan_mode" | "thinking_enabled" | "subagent_enabled"
   > & {
     mode: "flash" | "thinking" | "pro" | "ultra" | undefined;
+    reasoning_effort?: "minimal" | "low" | "medium" | "high";
   };
   extraHeader?: React.ReactNode;
   isNewThread?: boolean;
@@ -116,6 +117,7 @@ export function InputBox({
       "thread_id" | "is_plan_mode" | "thinking_enabled" | "subagent_enabled"
     > & {
       mode: "flash" | "thinking" | "pro" | "ultra" | undefined;
+      reasoning_effort?: "minimal" | "low" | "medium" | "high";
     },
   ) => void;
   onSubmit?: (message: PromptInputMessage) => void;
@@ -159,6 +161,11 @@ export function InputBox({
     [selectedModel],
   );
 
+  const supportReasoningEffort = useMemo(
+    () => selectedModel?.supports_reasoning_effort ?? false,
+    [selectedModel],
+  );
+
   const handleModelSelect = useCallback(
     (model_name: string) => {
       const model = models.find((m) => m.name === model_name);
@@ -169,6 +176,7 @@ export function InputBox({
         ...context,
         model_name,
         mode: getResolvedMode(context.mode, model.supports_thinking ?? false),
+        reasoning_effort: context.reasoning_effort,
       });
       setModelDialogOpen(false);
     },
@@ -180,10 +188,22 @@ export function InputBox({
       onContextChange?.({
         ...context,
         mode: getResolvedMode(mode, supportThinking),
+        reasoning_effort: mode === "ultra" ? "high" : mode === "pro" ? "medium" : mode === "thinking" ? "low" : "minimal",
       });
     },
     [onContextChange, context, supportThinking],
   );
+
+  const handleReasoningEffortSelect = useCallback(
+    (effort: "minimal" | "low" | "medium" | "high") => {
+      onContextChange?.({
+        ...context,
+        reasoning_effort: effort,
+      });
+    },
+    [onContextChange, context],
+  );
+
   const handleSubmit = useCallback(
     async (message: PromptInputMessage) => {
       if (status === "streaming") {
@@ -244,9 +264,9 @@ export function InputBox({
             <ModeHoverGuide
               mode={
                 context.mode === "flash" ||
-                context.mode === "thinking" ||
+                  context.mode === "thinking" ||
-                context.mode === "pro" ||
+                  context.mode === "pro" ||
-                context.mode === "ultra"
+                  context.mode === "ultra"
                   ? context.mode
                   : "flash"
               }
@@ -297,7 +317,7 @@ export function InputBox({
                           className={cn(
                             "mr-2 size-4",
                             context.mode === "flash" &&
-                              "text-accent-foreground",
+                            "text-accent-foreground",
                           )}
                         />
                         {t.inputBox.flashMode}
@@ -327,7 +347,7 @@ export function InputBox({
                             className={cn(
                               "mr-2 size-4",
                               context.mode === "thinking" &&
-                                "text-accent-foreground",
+                              "text-accent-foreground",
                             )}
                           />
                           {t.inputBox.reasoningMode}
@@ -409,6 +429,116 @@ export function InputBox({
               </DropdownMenuGroup>
             </PromptInputActionMenuContent>
           </PromptInputActionMenu>
+          {supportReasoningEffort && context.mode !== "flash" && (
+            <PromptInputActionMenu>
+              <PromptInputActionMenuTrigger className="gap-1! px-2!">
+                <div className="text-xs font-normal">
+                  {t.inputBox.reasoningEffort}:
+                  {context.reasoning_effort === "minimal" && " " + t.inputBox.reasoningEffortMinimal}
+                  {context.reasoning_effort === "low" && " " + t.inputBox.reasoningEffortLow}
+                  {context.reasoning_effort === "medium" && " " + t.inputBox.reasoningEffortMedium}
+                  {context.reasoning_effort === "high" && " " + t.inputBox.reasoningEffortHigh}
+                </div>
+              </PromptInputActionMenuTrigger>
+              <PromptInputActionMenuContent className="w-70">
+                <DropdownMenuGroup>
+                  <DropdownMenuLabel className="text-muted-foreground text-xs">
+                    {t.inputBox.reasoningEffort}
+                  </DropdownMenuLabel>
+                  <PromptInputActionMenu>
+                    <PromptInputActionMenuItem
+                      className={cn(
+                        context.reasoning_effort === "minimal"
+                          ? "text-accent-foreground"
+                          : "text-muted-foreground/65",
+                      )}
+                      onSelect={() => handleReasoningEffortSelect("minimal")}
+                    >
+                      <div className="flex flex-col gap-2">
+                        <div className="flex items-center gap-1 font-bold">
+                          {t.inputBox.reasoningEffortMinimal}
+                        </div>
+                        <div className="pl-2 text-xs">
+                          {t.inputBox.reasoningEffortMinimalDescription}
+                        </div>
+                      </div>
+                      {context.reasoning_effort === "minimal" ? (
+                        <CheckIcon className="ml-auto size-4" />
+                      ) : (
+                        <div className="ml-auto size-4" />
+                      )}
+                    </PromptInputActionMenuItem>
+                    <PromptInputActionMenuItem
+                      className={cn(
+                        context.reasoning_effort === "low"
+                          ? "text-accent-foreground"
+                          : "text-muted-foreground/65",
+                      )}
+                      onSelect={() => handleReasoningEffortSelect("low")}
+                    >
+                      <div className="flex flex-col gap-2">
+                        <div className="flex items-center gap-1 font-bold">
+                          {t.inputBox.reasoningEffortLow}
+                        </div>
+                        <div className="pl-2 text-xs">
+                          {t.inputBox.reasoningEffortLowDescription}
+                        </div>
+                      </div>
+                      {context.reasoning_effort === "low" ? (
+                        <CheckIcon className="ml-auto size-4" />
+                      ) : (
+                        <div className="ml-auto size-4" />
+                      )}
+                    </PromptInputActionMenuItem>
+                    <PromptInputActionMenuItem
+                      className={cn(
+                        context.reasoning_effort === "medium" || !context.reasoning_effort
+                          ? "text-accent-foreground"
+                          : "text-muted-foreground/65",
+                      )}
+                      onSelect={() => handleReasoningEffortSelect("medium")}
+                    >
+                      <div className="flex flex-col gap-2">
+                        <div className="flex items-center gap-1 font-bold">
+                          {t.inputBox.reasoningEffortMedium}
+                        </div>
+                        <div className="pl-2 text-xs">
+                          {t.inputBox.reasoningEffortMediumDescription}
+                        </div>
+                      </div>
+                      {context.reasoning_effort === "medium" || !context.reasoning_effort ? (
+                        <CheckIcon className="ml-auto size-4" />
+                      ) : (
+                        <div className="ml-auto size-4" />
+                      )}
+                    </PromptInputActionMenuItem>
+                    <PromptInputActionMenuItem
+                      className={cn(
+                        context.reasoning_effort === "high"
+                          ? "text-accent-foreground"
+                          : "text-muted-foreground/65",
+                      )}
+                      onSelect={() => handleReasoningEffortSelect("high")}
+                    >
+                      <div className="flex flex-col gap-2">
+                        <div className="flex items-center gap-1 font-bold">
+                          {t.inputBox.reasoningEffortHigh}
+                        </div>
+                        <div className="pl-2 text-xs">
+                          {t.inputBox.reasoningEffortHighDescription}
+                        </div>
+                      </div>
+                      {context.reasoning_effort === "high" ? (
+                        <CheckIcon className="ml-auto size-4" />
+                      ) : (
+                        <div className="ml-auto size-4" />
+                      )}
+                    </PromptInputActionMenuItem>
+                  </PromptInputActionMenu>
+                </DropdownMenuGroup>
+              </PromptInputActionMenuContent>
+            </PromptInputActionMenu>
+          )}
         </PromptInputTools>
         <PromptInputTools>
           <ModelSelector

frontend/src/components/workspace/messages/message-list.tsx

@@ -34,20 +34,18 @@ export function MessageList({
   className,
   threadId,
   thread,
-  messagesOverride,
+  messages,
   paddingBottom = 160,
 }: {
   className?: string;
   threadId: string;
   thread: UseStream<AgentThreadState>;
-  /** When set (e.g. from onFinish), use instead of thread.messages so SSE end shows complete state. */
+  messages: Message[];
-  messagesOverride?: Message[];
   paddingBottom?: number;
 }) {
   const { t } = useI18n();
   const rehypePlugins = useRehypeSplitWordsIntoSpans(thread.isLoading);
   const updateSubtask = useUpdateSubtask();
-  const messages = messagesOverride ?? thread.messages;
   if (thread.isThreadLoading) {
     return <MessageListSkeleton />;
   }

frontend/src/core/i18n/locales/en-US.ts

@@ -82,6 +82,15 @@ export const enUS: Translations = {
     ultraMode: "Ultra",
     ultraModeDescription:
       "Pro mode with subagents to divide work; best for complex multi-step tasks",
+    reasoningEffort: "Reasoning Effort",
+    reasoningEffortMinimal: "Minimal",
+    reasoningEffortMinimalDescription: "Retrieval + Direct Output",
+    reasoningEffortLow: "Low",
+    reasoningEffortLowDescription: "Simple Logic Check + Shallow Deduction",
+    reasoningEffortMedium: "Medium",
+    reasoningEffortMediumDescription: "Multi-layer Logic Analysis + Basic Verification",
+    reasoningEffortHigh: "High",
+    reasoningEffortHighDescription: "Full-dimensional Logic Deduction + Multi-path Verification + Backward Check",
     searchModels: "Search models...",
     surpriseMe: "Surprise",
     surpriseMePrompt: "Surprise me",

frontend/src/core/i18n/locales/types.ts

@@ -64,6 +64,15 @@ export interface Translations {
     proModeDescription: string;
     ultraMode: string;
     ultraModeDescription: string;
+    reasoningEffort: string;
+    reasoningEffortMinimal: string;
+    reasoningEffortMinimalDescription: string;
+    reasoningEffortLow: string;
+    reasoningEffortLowDescription: string;
+    reasoningEffortMedium: string;
+    reasoningEffortMediumDescription: string;
+    reasoningEffortHigh: string;
+    reasoningEffortHighDescription: string;
     searchModels: string;
     surpriseMe: string;
     surpriseMePrompt: string;

frontend/src/core/i18n/locales/zh-CN.ts

@@ -80,6 +80,15 @@ export const zhCN: Translations = {
     ultraMode: "Ultra",
     ultraModeDescription:
       "继承自 Pro 模式，可调用子代理分工协作，适合复杂多步骤任务，能力最强",
+    reasoningEffort: "推理深度",
+    reasoningEffortMinimal: "最低",
+    reasoningEffortMinimalDescription: "检索 + 直接输出",
+    reasoningEffortLow: "低",
+    reasoningEffortLowDescription: "简单逻辑校验 + 浅层推演",
+    reasoningEffortMedium: "中",
+    reasoningEffortMediumDescription: "多层逻辑分析 + 基础验证",
+    reasoningEffortHigh: "高",
+    reasoningEffortHighDescription: "全维度逻辑推演 + 多路径验证 + 反推校验",
     searchModels: "搜索模型...",
     surpriseMe: "小惊喜",
     surpriseMePrompt: "给我一个小惊喜吧",

frontend/src/core/models/types.ts

@@ -4,4 +4,5 @@ export interface Model {
   display_name: string;
   description?: string | null;
   supports_thinking?: boolean;
+  supports_reasoning_effort?: boolean;
 }

frontend/src/core/settings/local.ts

@@ -7,6 +7,7 @@ export const DEFAULT_LOCAL_SETTINGS: LocalSettings = {
   context: {
     model_name: undefined,
     mode: undefined,
+    reasoning_effort: undefined,
   },
   layout: {
     sidebar_collapsed: false,
@@ -24,6 +25,7 @@ export interface LocalSettings {
     "thread_id" | "is_plan_mode" | "thinking_enabled" | "subagent_enabled"
   > & {
     mode: "flash" | "thinking" | "pro" | "ultra" | undefined;
+    reasoning_effort?: "minimal" | "low" | "medium" | "high";
   };
   layout: {
     sidebar_collapsed: boolean;

frontend/src/core/threads/types.ts

@@ -18,4 +18,5 @@ export interface AgentThreadContext extends Record<string, unknown> {
   thinking_enabled: boolean;
   is_plan_mode: boolean;
   subagent_enabled: boolean;
+  reasoning_effort?: "minimal" | "low" | "medium" | "high";
 }