feat(studio): 回退/重roll 与 R5 用户确认下一步

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/api/routes/studioRoute.py

@@ -11,6 +11,7 @@ from models.studio_models import (
     PipelineDefinition,
     RenameRunRequest,
     RunMessageRequest,
+    RunRerollRequest,
     StudioProject,
     StudioProjectSummary,
     StudioRun,
@@ -249,6 +250,79 @@ async def send_studio_run_message(
         raise HTTPException(status_code=500, detail=f"消息处理失败：{e}")
 
 
+@router.post("/projects/{project_id}/runs/{run_id}/undo", response_model=StudioRun)
+async def undo_studio_run(project_id: str, run_id: str):
+    try:
+        return studio_run_service.undo_run(project_id, run_id)
+    except FileNotFoundError as e:
+        raise HTTPException(status_code=404, detail=str(e))
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        logger.error(
+            "Failed to undo studio run %s/%s: %s", project_id, run_id, e
+        )
+        raise HTTPException(status_code=500, detail=f"回退失败：{e}")
+
+
+@router.post("/projects/{project_id}/runs/{run_id}/reroll")
+async def reroll_studio_run(
+    project_id: str, run_id: str, req: RunRerollRequest
+):
+    if req.stream:
+        async def ndjson_stream():
+            try:
+                async for event in studio_run_service.reroll_run_stream(
+                    project_id,
+                    run_id,
+                    profile_id=req.profileId,
+                    api_config=req.apiConfig,
+                ):
+                    yield json.dumps(event, ensure_ascii=False) + "\n"
+            except FileNotFoundError as e:
+                yield json.dumps(
+                    {"type": "error", "detail": str(e)}, ensure_ascii=False
+                ) + "\n"
+            except ValueError as e:
+                yield json.dumps(
+                    {"type": "error", "detail": str(e)}, ensure_ascii=False
+                ) + "\n"
+            except Exception as e:
+                logger.error(
+                    "Failed to stream studio run reroll %s/%s: %s",
+                    project_id,
+                    run_id,
+                    e,
+                )
+                yield json.dumps(
+                    {"type": "error", "detail": f"重 roll 失败：{e}"},
+                    ensure_ascii=False,
+                ) + "\n"
+
+        return StreamingResponse(
+            ndjson_stream(),
+            media_type="application/x-ndjson",
+        )
+
+    try:
+        return await studio_run_service.reroll_run(
+            project_id,
+            run_id,
+            stream=req.stream,
+            profile_id=req.profileId,
+            api_config=req.apiConfig,
+        )
+    except FileNotFoundError as e:
+        raise HTTPException(status_code=404, detail=str(e))
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        logger.error(
+            "Failed to reroll studio run %s/%s: %s", project_id, run_id, e
+        )
+        raise HTTPException(status_code=500, detail=f"重 roll 失败：{e}")
+
+
 @router.delete("/projects/{project_id}/runs/{run_id}")
 async def delete_studio_run(project_id: str, run_id: str):
     try:

backend/models/studio_models.py

@@ -183,6 +183,14 @@ class PromptBlock(BaseModel):
     source: str = "auto"  # auto | manual | workflow
 
 
+class TurnSnapshot(BaseModel):
+    """State captured before each LLM turn (for undo)."""
+    lastDraft: Optional[Dict[str, Any]] = None
+    lastToolResponse: Optional[LastToolResponse] = None
+    stepMessages: List[StepMessage] = Field(default_factory=list)
+    timestamp: Optional[str] = None
+
+
 class StudioNodeRunState(BaseModel):
     nodeId: str
     displayName: str
@@ -192,6 +200,7 @@ class StudioNodeRunState(BaseModel):
     lastDraft: Optional[Dict[str, Any]] = None
     lastToolResponse: Optional[LastToolResponse] = None
     stepMessages: List[StepMessage] = Field(default_factory=list)
+    turnHistory: List[TurnSnapshot] = Field(default_factory=list)
 
 
 class StudioRun(BaseModel):
@@ -220,6 +229,12 @@ class RunMessageRequest(BaseModel):
     apiConfig: Optional[Dict[str, str]] = None
 
 
+class RunRerollRequest(BaseModel):
+    stream: bool = False
+    profileId: Optional[str] = None
+    apiConfig: Optional[Dict[str, str]] = None
+
+
 class RenameRunRequest(BaseModel):
     title: str = Field(..., min_length=1, max_length=120)
 

backend/services/studio_run_service.py

@@ -20,6 +20,7 @@ from models.studio_models import (
     StudioRun,
     StudioRunStatus,
     StudioRunSummary,
+    TurnSnapshot,
 )
 from services.character_service import CharacterService
 from services.studio_context_service import assemble_prompt_blocks, store_context_on_run
@@ -92,6 +93,44 @@ def _next_enabled_node_id(pipeline: PipelineDefinition, after_node_id: str) -> O
     return None
 
 
+def _snapshot_node_state(state: StudioNodeRunState) -> TurnSnapshot:
+    return TurnSnapshot(
+        lastDraft=copy.deepcopy(state.lastDraft) if state.lastDraft else None,
+        lastToolResponse=(
+            state.lastToolResponse.model_copy()
+            if state.lastToolResponse
+            else None
+        ),
+        stepMessages=[m.model_copy() for m in (state.stepMessages or [])],
+        timestamp=datetime.now().isoformat(),
+    )
+
+
+def _apply_snapshot(
+    state: StudioNodeRunState, snapshot: TurnSnapshot
+) -> StudioNodeRunState:
+    updated = state.model_copy()
+    updated.lastDraft = (
+        copy.deepcopy(snapshot.lastDraft) if snapshot.lastDraft else None
+    )
+    updated.lastToolResponse = (
+        snapshot.lastToolResponse.model_copy()
+        if snapshot.lastToolResponse
+        else None
+    )
+    updated.stepMessages = [
+        m.model_copy() for m in (snapshot.stepMessages or [])
+    ]
+    return updated
+
+
+def _find_last_user_message_index(step_messages: list) -> int:
+    for i in range(len(step_messages) - 1, -1, -1):
+        if step_messages[i].role == "user":
+            return i
+    return -1
+
+
 class StudioRunService:
     def __init__(self) -> None:
         self._character_service = CharacterService()
@@ -272,6 +311,9 @@ class StudioRunService:
             workflow_variables, last_draft = self._execute_init_bind(
                 project_id, run, current_node, display_params
             )
+        elif current_node.skillId == "studio.worldbook_entry":
+            if not current_state.lastDraft:
+                raise ValueError("请先生成并确认当前产物后再进入下一步")
         else:
             raise NotImplementedError(
                 f"技能「{current_node.skillId}」的执行尚未实现（R2+）"
@@ -414,15 +456,14 @@ class StudioRunService:
                     "run": updated_run.model_dump(mode="json"),
                 }
 
-    def _prepare_run_message(
+    def _prepare_active_worldbook_step(
         self,
         project_id: str,
         run_id: str,
-        trimmed: str,
     ) -> tuple[StudioRun, StudioNode, StudioNodeRunState, str]:
         run = self.get_run(project_id, run_id)
         if run.status != StudioRunStatus.RUNNING:
-            raise ValueError("运行未处于进行中，无法发送消息")
+            raise ValueError("运行未处于进行中，无法操作")
 
         current_node_id = run.currentNodeId
         if not current_node_id:
@@ -445,6 +486,16 @@ class StudioRunService:
 
         return run, current_node, current_state, current_node_id
 
+    def _prepare_run_message(
+        self,
+        project_id: str,
+        run_id: str,
+        trimmed: str,
+    ) -> tuple[StudioRun, StudioNode, StudioNodeRunState, str]:
+        if not trimmed:
+            raise ValueError("消息内容不能为空")
+        return self._prepare_active_worldbook_step(project_id, run_id)
+
     def _persist_run_message_turn(
         self,
         project_id: str,
@@ -457,6 +508,8 @@ class StudioRunService:
         last_tool_response,
         user_msg,
         assistant_msg,
+        *,
+        push_snapshot: bool = True,
     ) -> StudioRun:
         step_messages = list(step_messages)
         step_messages.extend([user_msg, assistant_msg])
@@ -466,6 +519,205 @@ class StudioRunService:
         for state in run.nodeStates:
             updated = state.model_copy()
             if state.nodeId == current_node_id:
+                if push_snapshot:
+                    turn_history = list(state.turnHistory or [])
+                    turn_history.append(_snapshot_node_state(state))
+                    updated.turnHistory = turn_history
+                updated.lastDraft = last_draft
+                updated.lastToolResponse = last_tool_response
+                updated.stepMessages = step_messages
+            new_node_states.append(updated)
+
+        updated_run = run.model_copy(
+            update={
+                "nodeStates": new_node_states,
+                "lastPromptBlocks": prompt_blocks,
+                "updatedAt": now,
+            }
+        )
+        updated_run = store_context_on_run(updated_run, current_node_id)
+        self._save_run(project_id, run_id, updated_run)
+        return updated_run
+
+    def undo_run(self, project_id: str, run_id: str) -> StudioRun:
+        """Restore the active step to the state before the last LLM turn."""
+        run, _, current_state, current_node_id = self._prepare_active_worldbook_step(
+            project_id, run_id
+        )
+
+        turn_history = list(current_state.turnHistory or [])
+        if not turn_history:
+            raise ValueError("无可回退的回合")
+
+        snapshot = turn_history.pop()
+        restored_state = _apply_snapshot(current_state, snapshot)
+        restored_state.turnHistory = turn_history
+
+        now = datetime.now().isoformat()
+        new_node_states: list[StudioNodeRunState] = []
+        for state in run.nodeStates:
+            if state.nodeId == current_node_id:
+                new_node_states.append(restored_state)
+            else:
+                new_node_states.append(state.model_copy())
+
+        updated_run = run.model_copy(
+            update={
+                "nodeStates": new_node_states,
+                "updatedAt": now,
+            }
+        )
+        updated_run = store_context_on_run(updated_run, current_node_id)
+        self._save_run(project_id, run_id, updated_run)
+        return updated_run
+
+    async def reroll_run(
+        self,
+        project_id: str,
+        run_id: str,
+        *,
+        stream: bool = False,
+        profile_id: Optional[str] = None,
+        api_config: Optional[Dict[str, str]] = None,
+    ) -> StudioRun:
+        """Re-run the last user turn with identical inputs (no new user message)."""
+        run, current_node, current_state, current_node_id = (
+            self._prepare_active_worldbook_step(project_id, run_id)
+        )
+
+        step_messages_all = list(current_state.stepMessages or [])
+        last_user_idx = _find_last_user_message_index(step_messages_all)
+        if last_user_idx < 0:
+            raise ValueError("当前步骤尚无用户消息，无法重 roll")
+
+        user_content = step_messages_all[last_user_idx].content
+        step_messages = step_messages_all[:last_user_idx]
+
+        pre_turn_draft = current_state.lastDraft
+        if current_state.turnHistory:
+            pre_turn_draft = current_state.turnHistory[-1].lastDraft
+
+        resolved_api = resolve_api_config(profile_id, api_config)
+        prompt_blocks = assemble_prompt_blocks(run, current_node_id)
+
+        last_draft, last_tool_response, user_msg, assistant_msg = (
+            await studio_step_respond(
+                node=current_node,
+                prompt_blocks=prompt_blocks,
+                step_messages=step_messages,
+                user_message=user_content,
+                existing_draft=pre_turn_draft,
+                api_config=resolved_api,
+                stream=stream,
+            )
+        )
+
+        return self._persist_reroll_turn(
+            project_id,
+            run_id,
+            run,
+            current_node_id,
+            current_state,
+            prompt_blocks,
+            step_messages,
+            last_draft,
+            last_tool_response,
+            user_msg,
+            assistant_msg,
+        )
+
+    async def reroll_run_stream(
+        self,
+        project_id: str,
+        run_id: str,
+        *,
+        profile_id: Optional[str] = None,
+        api_config: Optional[Dict[str, str]] = None,
+    ) -> AsyncGenerator[Dict[str, Any], None]:
+        """Stream thinking during reroll, then persist replaced turn."""
+        run, current_node, current_state, current_node_id = (
+            self._prepare_active_worldbook_step(project_id, run_id)
+        )
+
+        step_messages_all = list(current_state.stepMessages or [])
+        last_user_idx = _find_last_user_message_index(step_messages_all)
+        if last_user_idx < 0:
+            raise ValueError("当前步骤尚无用户消息，无法重 roll")
+
+        user_content = step_messages_all[last_user_idx].content
+        step_messages = step_messages_all[:last_user_idx]
+
+        pre_turn_draft = current_state.lastDraft
+        if current_state.turnHistory:
+            pre_turn_draft = current_state.turnHistory[-1].lastDraft
+
+        resolved_api = resolve_api_config(profile_id, api_config)
+        prompt_blocks = assemble_prompt_blocks(run, current_node_id)
+
+        async for event in studio_step_respond_stream(
+            node=current_node,
+            prompt_blocks=prompt_blocks,
+            step_messages=step_messages,
+            user_message=user_content,
+            existing_draft=pre_turn_draft,
+            api_config=resolved_api,
+        ):
+            if event.get("type") == "thinking_delta":
+                yield event
+                continue
+
+            if event.get("type") == "complete":
+                from models.studio_models import LastToolResponse, StepMessage
+
+                last_draft = event["last_draft"]
+                last_tool_response = LastToolResponse(**event["last_tool_response"])
+                user_msg = StepMessage(**event["user_msg"])
+                assistant_msg = StepMessage(**event["assistant_msg"])
+
+                updated_run = self._persist_reroll_turn(
+                    project_id,
+                    run_id,
+                    run,
+                    current_node_id,
+                    current_state,
+                    prompt_blocks,
+                    step_messages,
+                    last_draft,
+                    last_tool_response,
+                    user_msg,
+                    assistant_msg,
+                )
+                yield {
+                    "type": "complete",
+                    "run": updated_run.model_dump(mode="json"),
+                }
+
+    def _persist_reroll_turn(
+        self,
+        project_id: str,
+        run_id: str,
+        run: StudioRun,
+        current_node_id: str,
+        current_state: StudioNodeRunState,
+        prompt_blocks: list,
+        step_messages: list,
+        last_draft: Dict[str, Any],
+        last_tool_response,
+        user_msg,
+        assistant_msg,
+    ) -> StudioRun:
+        """Replace the last turn; snapshot current state so reroll is undoable."""
+        step_messages = list(step_messages)
+        step_messages.extend([user_msg, assistant_msg])
+        now = datetime.now().isoformat()
+
+        new_node_states: list[StudioNodeRunState] = []
+        for state in run.nodeStates:
+            updated = state.model_copy()
+            if state.nodeId == current_node_id:
+                turn_history = list(current_state.turnHistory or [])
+                turn_history.append(_snapshot_node_state(current_state))
+                updated.turnHistory = turn_history
                 updated.lastDraft = last_draft
                 updated.lastToolResponse = last_tool_response
                 updated.stepMessages = step_messages

frontend/src/Store/Studio/StudioSlice.jsx

@@ -2,6 +2,79 @@ import { create } from 'zustand';
 
 const DEFAULT_TEMPLATE_ID = 'builtin.studio.example';
 
+async function resolveStudioApiConfig() {
+  let profileId = null;
+  let apiConfig = {};
+  try {
+    const { default: useApiConfigStore } = await import('../SideBarLeft/ApiConfigSlice');
+    const apiState = useApiConfigStore.getState();
+    profileId = apiState.currentProfile?.id || null;
+    const mainLLM = apiState.currentProfile?.apis?.mainLLM;
+    if (mainLLM) {
+      apiConfig = {
+        api_url: mainLLM.apiUrl || '',
+        model: mainLLM.model || '',
+      };
+    }
+  } catch {
+    /* optional store */
+  }
+  return { profileId, apiConfig };
+}
+
+async function consumeStudioStreamResponse(res, set) {
+  const reader = res.body.getReader();
+  const decoder = new TextDecoder();
+  let buffer = '';
+  let finalRun = null;
+
+  while (true) {
+    const { done, value } = await reader.read();
+    if (done) break;
+    buffer += decoder.decode(value, { stream: true });
+    const lines = buffer.split('\n');
+    buffer = lines.pop() || '';
+    for (const line of lines) {
+      if (!line.trim()) continue;
+      const event = JSON.parse(line);
+      if (event.type === 'thinking_delta') {
+        set({ runStreamingThinking: event.content || '' });
+      } else if (event.type === 'complete') {
+        finalRun = event.run;
+      } else if (event.type === 'error') {
+        throw new Error(event.detail || '流式处理失败');
+      }
+    }
+  }
+
+  if (buffer.trim()) {
+    const event = JSON.parse(buffer);
+    if (event.type === 'complete') {
+      finalRun = event.run;
+    } else if (event.type === 'error') {
+      throw new Error(event.detail || '流式处理失败');
+    } else if (event.type === 'thinking_delta') {
+      set({ runStreamingThinking: event.content || '' });
+    }
+  }
+
+  if (!finalRun) {
+    throw new Error('流式响应未完成');
+  }
+  return finalRun;
+}
+
+async function parseStudioErrorResponse(res) {
+  let detail = await res.text();
+  try {
+    const parsed = JSON.parse(detail);
+    detail = parsed.detail || detail;
+  } catch {
+    /* keep raw text */
+  }
+  return detail;
+}
+
 function migrateScoringInNode(node) {
   const scoring = node.config?.scoring;
   if (!scoring || scoring.dimensions?.length) return node;
@@ -497,24 +570,7 @@ const useStudioStore = create((set, get) => ({
     if (!runProjectId || !currentRunId) return null;
     set({ runMessaging: true, runStreamingThinking: null, runError: null });
     try {
-      let profileId = null;
+      const { profileId, apiConfig } = await resolveStudioApiConfig();
-      let apiConfig = {};
-      try {
-        const { default: useApiConfigStore } = await import(
-          '../SideBarLeft/ApiConfigSlice'
-        );
-        const apiState = useApiConfigStore.getState();
-        profileId = apiState.currentProfile?.id || null;
-        const mainLLM = apiState.currentProfile?.apis?.mainLLM;
-        if (mainLLM) {
-          apiConfig = {
-            api_url: mainLLM.apiUrl || '',
-            model: mainLLM.model || '',
-          };
-        }
-      } catch {
-        /* optional store */
-      }
 
       const res = await fetch(
         `/api/studio/projects/${encodeURIComponent(runProjectId)}/runs/${encodeURIComponent(currentRunId)}/message`,
@@ -531,56 +587,11 @@ const useStudioStore = create((set, get) => ({
       );
 
       if (!res.ok) {
-        let detail = await res.text();
+        throw new Error((await parseStudioErrorResponse(res)) || '发送消息失败');
-        try {
-          const parsed = JSON.parse(detail);
-          detail = parsed.detail || detail;
-        } catch {
-          /* keep raw text */
-        }
-        throw new Error(detail || '发送消息失败');
       }
 
       if (stream && res.body) {
-        const reader = res.body.getReader();
+        const finalRun = await consumeStudioStreamResponse(res, set);
-        const decoder = new TextDecoder();
-        let buffer = '';
-        let finalRun = null;
-
-        while (true) {
-          const { done, value } = await reader.read();
-          if (done) break;
-          buffer += decoder.decode(value, { stream: true });
-          const lines = buffer.split('\n');
-          buffer = lines.pop() || '';
-          for (const line of lines) {
-            if (!line.trim()) continue;
-            const event = JSON.parse(line);
-            if (event.type === 'thinking_delta') {
-              set({ runStreamingThinking: event.content || '' });
-            } else if (event.type === 'complete') {
-              finalRun = event.run;
-            } else if (event.type === 'error') {
-              throw new Error(event.detail || '流式消息处理失败');
-            }
-          }
-        }
-
-        if (buffer.trim()) {
-          const event = JSON.parse(buffer);
-          if (event.type === 'complete') {
-            finalRun = event.run;
-          } else if (event.type === 'error') {
-            throw new Error(event.detail || '流式消息处理失败');
-          } else if (event.type === 'thinking_delta') {
-            set({ runStreamingThinking: event.content || '' });
-          }
-        }
-
-        if (!finalRun) {
-          throw new Error('流式响应未完成');
-        }
-
         set({
           currentRun: finalRun,
           runMessaging: false,
@@ -606,6 +617,86 @@ const useStudioStore = create((set, get) => ({
     }
   },
 
+  undoRun: async () => {
+    const { runProjectId, currentRunId } = get();
+    if (!runProjectId || !currentRunId) return null;
+    set({ runMessaging: true, runStreamingThinking: null, runError: null });
+    try {
+      const res = await fetch(
+        `/api/studio/projects/${encodeURIComponent(runProjectId)}/runs/${encodeURIComponent(currentRunId)}/undo`,
+        { method: 'POST' }
+      );
+      if (!res.ok) {
+        throw new Error((await parseStudioErrorResponse(res)) || '回退失败');
+      }
+      const run = await res.json();
+      set({
+        currentRun: run,
+        runMessaging: false,
+        runStreamingThinking: null,
+      });
+      return run;
+    } catch (e) {
+      set({
+        runMessaging: false,
+        runStreamingThinking: null,
+        runError: e.message || '回退失败',
+      });
+      return null;
+    }
+  },
+
+  rerollRun: async ({ stream = false } = {}) => {
+    const { runProjectId, currentRunId } = get();
+    if (!runProjectId || !currentRunId) return null;
+    set({ runMessaging: true, runStreamingThinking: null, runError: null });
+    try {
+      const { profileId, apiConfig } = await resolveStudioApiConfig();
+
+      const res = await fetch(
+        `/api/studio/projects/${encodeURIComponent(runProjectId)}/runs/${encodeURIComponent(currentRunId)}/reroll`,
+        {
+          method: 'POST',
+          headers: { 'Content-Type': 'application/json' },
+          body: JSON.stringify({
+            stream,
+            profileId,
+            apiConfig,
+          }),
+        }
+      );
+
+      if (!res.ok) {
+        throw new Error((await parseStudioErrorResponse(res)) || '重 roll 失败');
+      }
+
+      if (stream && res.body) {
+        const finalRun = await consumeStudioStreamResponse(res, set);
+        set({
+          currentRun: finalRun,
+          runMessaging: false,
+          runStreamingThinking: null,
+        });
+        return finalRun;
+      }
+
+      const run = await res.json();
+      set({
+        currentRun: run,
+        runMessaging: false,
+        runStreamingThinking: null,
+      });
+      return run;
+    } catch (e) {
+      set({
+        runMessaging: false,
+        runStreamingThinking: null,
+        runError: e.message || '重 roll 失败',
+      });
+      return null;
+    }
+  },
+
   deleteRun: async (runId) => {
     const projectId = get().runProjectId;
     if (!projectId || !runId) return false;

frontend/src/components/Studio/StudioRunChat.jsx

@@ -49,17 +49,15 @@ function StudioRunChat({
 
   const lastUserIdx = findLastUserMessageIndex(stepMessages);
   const historyMessages =
-    lastUserIdx > 0 ? stepMessages.slice(0, lastUserIdx) : [];
+    lastUserIdx > 0
+      ? stepMessages.slice(0, lastUserIdx).filter((msg) => msg.role === 'user')
+      : [];
   const lastUserMessage =
     lastUserIdx >= 0 ? stepMessages[lastUserIdx] : pendingUserText
       ? { role: 'user', content: pendingUserText }
       : null;
 
-  const summaryText =
+  const summaryText = evaluation || null;
-    evaluation ||
-    (lastUserIdx >= 0 && stepMessages[lastUserIdx + 1]?.role === 'assistant'
-      ? stepMessages[lastUserIdx + 1].content
-      : null);
 
   const hasFocusContent =
     thinking || summaryText || pendingUserText || sending || lastUserMessage;
@@ -124,11 +122,9 @@ function StudioRunChat({
             {historyMessages.map((msg) => (
               <div
                 key={msg.id}
-                className={`studio-run-chat-history-item role-${msg.role}`}
+                className="studio-run-chat-history-item role-user"
               >
-                <span className="studio-run-chat-history-role">
+                <span className="studio-run-chat-history-role">你</span>
-                  {msg.role === 'user' ? '你' : '助手'}
-                </span>
                 <span className="studio-run-chat-history-text">{msg.content}</span>
               </div>
             ))}

frontend/src/components/Studio/StudioRunPage.css

@@ -752,6 +752,43 @@
   cursor: not-allowed;
 }
 
+.studio-run-turn-actions__row {
+  display: flex;
+  gap: var(--spacing-xs);
+}
+
+.studio-run-turn-btn {
+  flex: 1;
+  padding: var(--spacing-sm) var(--spacing-md);
+  border: 1px solid var(--color-border-light);
+  border-radius: var(--radius-md);
+  background: var(--color-bg-secondary);
+  color: var(--color-text-primary);
+  font-size: 0.85rem;
+  font-weight: 500;
+  cursor: pointer;
+  transition: background 0.15s, border-color 0.15s;
+}
+
+.studio-run-turn-btn:hover:not(:disabled) {
+  background: var(--color-bg-tertiary);
+  border-color: var(--color-border);
+}
+
+.studio-run-turn-btn:disabled {
+  opacity: 0.45;
+  cursor: not-allowed;
+}
+
+.studio-run-turn-btn--reroll {
+  border-color: var(--color-accent);
+  color: var(--color-accent);
+}
+
+.studio-run-turn-btn--reroll:hover:not(:disabled) {
+  background: color-mix(in srgb, var(--color-accent) 12%, var(--color-bg-secondary));
+}
+
 .studio-run-stub-note {
   margin: 0;
   font-size: 0.65rem;

frontend/src/components/Studio/StudioRunPage.jsx

@@ -6,7 +6,7 @@ import {
   buildWorkflowVariableLabelMap,
   getWorkflowVariableLabel,
 } from './edit/workflowVariableLabels';
-import { resolveBoundCharacterName } from './studioRunUtils';
+import { resolveBoundCharacterName, canUndoRun, canRerollRun, canAdvanceNextStep } from './studioRunUtils';
 import useCharacterStore from '../../Store/SideBarLeft/CharacterSlice';
 
 import StudioContextBlockPopup from './StudioContextBlockPopup';
@@ -469,6 +469,8 @@ function StudioRunPage() {
     selectRun,
     advanceRun,
     sendRunMessage,
+    undoRun,
+    rerollRun,
     deleteRun,
     renameRun,
   } = useStudioStore();
@@ -629,8 +631,26 @@ function StudioRunPage() {
     }
   };
 
-  const handleNextStep = () => {
+  const handleUndo = async () => {
-    window.alert('（R5 占位：确认当前产物后将进入下一步）');
+    if (!isWorldbookActive || runMessaging || !canUndoRun(activeNodeState)) return;
+    await undoRun();
+  };
+
+  const handleReroll = async () => {
+    if (!isWorldbookActive || runMessaging || !canRerollRun(activeNodeState)) return;
+    await rerollRun({ stream: streamOutput });
+  };
+
+  const handleNextStep = async () => {
+    if (!isWorldbookActive || runAdvancing || runMessaging || !canAdvanceNextStep(activeNodeState)) {
+      return;
+    }
+    const run = await advanceRun({});
+    if (run) {
+      setChatInput('');
+      setToolOptionIndex(0);
+      setPendingUserText(null);
+    }
   };
 
   const handleDeleteRun = async (runId) => {
@@ -659,6 +679,10 @@ function StudioRunPage() {
   const inSession = runSessionEntered && !!currentRun;
   const showToolCarousel = inSession && isWorldbookActive && toolQuestions.length > 0;
   const showNextStep = inSession && isWorldbookActive;
+  const canUndo = canUndoRun(activeNodeState);
+  const canReroll = canRerollRun(activeNodeState);
+  const canNextStep = canAdvanceNextStep(activeNodeState);
+  const showTurnActions = inSession && isWorldbookActive;
 
   const renderRunList = () => (
     <>
@@ -881,13 +905,40 @@ function StudioRunPage() {
         />
       )}
 
+      {showTurnActions && (
+        <div className="studio-run-right-section studio-run-turn-actions">
+          <h2 className="studio-run-section-title">回合控制</h2>
+          <div className="studio-run-turn-actions__row">
+            <button
+              type="button"
+              className="studio-run-turn-btn studio-run-turn-btn--undo"
+              onClick={handleUndo}
+              disabled={runAdvancing || runMessaging || !canUndo}
+              title={canUndo ? '回退到上一回合' : '无可回退的回合'}
+            >
+              回退
+            </button>
+            <button
+              type="button"
+              className="studio-run-turn-btn studio-run-turn-btn--reroll"
+              onClick={handleReroll}
+              disabled={runAdvancing || runMessaging || !canReroll}
+              title={canReroll ? '用相同输入重新生成' : '尚无用户消息'}
+            >
+              重roll
+            </button>
+          </div>
+        </div>
+      )}
+
       {showNextStep && (
         <div className="studio-run-right-section studio-run-right-actions">
           <button
             type="button"
             className="studio-run-next-btn"
             onClick={handleNextStep}
-            disabled={runAdvancing || runMessaging}
+            disabled={runAdvancing || runMessaging || !canNextStep}
+            title={canNextStep ? '确认当前产物并进入下一节点' : '请先生成当前步骤产物'}
           >
             下一步
           </button>

frontend/src/components/Studio/studioRunUtils.js

@@ -26,3 +26,18 @@ export function findLastUserMessageIndex(stepMessages = []) {
   }
   return -1;
 }
+
+/** Whether undo is available for the active node state. */
+export function canUndoRun(activeNodeState) {
+  return (activeNodeState?.turnHistory?.length ?? 0) > 0;
+}
+
+/** Whether reroll is available (at least one user message in current step). */
+export function canRerollRun(activeNodeState) {
+  return findLastUserMessageIndex(activeNodeState?.stepMessages) >= 0;
+}
+
+/** Whether the user may advance to the next pipeline node (R5). */
+export function canAdvanceNextStep(activeNodeState) {
+  return Boolean(activeNodeState?.lastDraft);
+}