fix: writing mode uses chat search then pipeline write only

Keep deep_research_report as a write-only deliverable from conversation materials, block post-success rewrite loops with a summary nudge, fill thin/empty pools from model knowledge, and open the sandbox only on real report.md content.

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

frontend-web/src/components/workspace/chats/chat-box.tsx

@@ -19,6 +19,7 @@ import {
   mergeArtifactPaths,
 } from "@/core/artifacts/listing";
 import { latestInFlightWriteFilePreview } from "@/core/artifacts/write-file-in-flight";
+import { shouldAutoOpenWritingArtifact } from "@/core/threads/writing-mode";
 import { getBackendBaseURL } from "@/core/config";
 import { isThreadRagModeLocked, useLocalSettings } from "@/core/settings";
 import { isSingleRoundRagMessage } from "@/core/threads/use-single-round-rag";
@@ -390,9 +391,12 @@ const ChatBox: React.FC<{
       ((artifactDirectoryModeEnabled && threadChanged) ||
         ((hasNewArtifact || !hadArtifacts) && !selectedArtifact))
     ) {
-      selectArtifact(nextArtifacts[nextArtifacts.length - 1]!);
-      setArtifactsOpen(true);
-      setSideTab("document");
+      const newest = nextArtifacts[nextArtifacts.length - 1]!;
+      if (shouldAutoOpenWritingArtifact(newest, thread.messages)) {
+        selectArtifact(newest);
+        setArtifactsOpen(true);
+        setSideTab("document");
+      }
     }
 
     // DO NOT automatically deselect the artifact when switching threads, because the artifacts auto discovering is not work now.
@@ -424,6 +428,7 @@ const ChatBox: React.FC<{
     setArtifacts,
     availableArtifacts,
     disableArtifacts,
+    thread.messages,
   ]);
 
   // Live sandbox: open as soon as any in-flight write_file has a path or

frontend-web/src/components/workspace/messages/message-group.tsx

@@ -69,6 +69,7 @@ import {
   type RuntimeDisplaySource,
 } from "@/core/skill-display/runtime";
 import { normalizeDisplaySources } from "@/core/skill-display/display-adapter";
+import { isInterceptedWritingReportWrite } from "@/core/threads/writing-mode";
 import { extractTitleFromMarkdown } from "@/core/utils/markdown";
 import { env } from "@/env";
 import { cn } from "@/lib/utils";
@@ -866,6 +867,22 @@ function convertToSteps(messages: Message[]): CoTStep[] {
         if (tool_call.name === "task") {
           continue;
         }
+        const writePath =
+          typeof (tool_call.args as { path?: unknown } | undefined)?.path === "string"
+            ? (tool_call.args as { path: string }).path
+            : "";
+        if (
+          (
+            tool_call.name === "write_file" ||
+            tool_call.name === "str_replace" ||
+            tool_call.name === "read_file" ||
+            tool_call.name === "read_multiple_files" ||
+            tool_call.name === "present_files"
+          ) &&
+          isInterceptedWritingReportWrite(writePath, message.id, messages)
+        ) {
+          continue;
+        }
         const step: CoTToolCallStep = {
           id: tool_call.id,
           messageId: message.id,

frontend-web/src/core/artifacts/write-file-in-flight.test.ts

@@ -61,6 +61,73 @@ test("latestInFlightWriteFilePreview keeps markdown when a later json write is i
   assert.match(preview?.artifactPath ?? "", /report\.md/);
 });
 
+test("latestInFlightWriteFilePreview skips intercepted custom outputs markdown", () => {
+  const preview = latestInFlightWriteFilePreview([
+    {
+      id: "m1",
+      type: "ai",
+      tool_calls: [
+        {
+          id: "w1",
+          name: "write_file",
+          args: {
+            path: "/mnt/user-data/outputs/ai-agent-architecture-paper.md",
+            content: "# 草稿\n",
+          },
+        },
+      ],
+    },
+  ]);
+  assert.equal(preview, null);
+});
+
+test("latestInFlightWriteFilePreview skips report.md while the first-turn pipeline is active", () => {
+  const preview = latestInFlightWriteFilePreview([
+    { type: "human", content: "写一篇论文" },
+    {
+      id: "m-pipe",
+      type: "ai",
+      tool_calls: [{ id: "p1", name: "deep_research_report", args: { topic: "课题" } }],
+    },
+    {
+      id: "m-write",
+      type: "ai",
+      tool_calls: [
+        {
+          id: "w1",
+          name: "write_file",
+          args: {
+            path: "/mnt/user-data/outputs/report.md",
+            content: "# 我自己写\n",
+          },
+        },
+      ],
+    },
+  ]);
+  assert.equal(preview, null);
+});
+
+test("latestInFlightWriteFilePreview still opens the injected research stub", () => {
+  const preview = latestInFlightWriteFilePreview([
+    {
+      id: "research-report-j1",
+      type: "ai",
+      tool_calls: [
+        {
+          id: "research-report-j1-write",
+          name: "write_file",
+          args: {
+            path: "/mnt/user-data/outputs/report.md",
+            content: "# 报告\n",
+          },
+        },
+      ],
+    },
+  ]);
+  assert.ok(preview);
+  assert.match(preview?.artifactPath ?? "", /report\.md/);
+});
+
 test("latestInFlightWriteFilePreview does not auto-open a json-only write", () => {
   const preview = latestInFlightWriteFilePreview([
     {

frontend-web/src/core/artifacts/write-file-in-flight.ts

@@ -1,3 +1,4 @@
+import { isInterceptedWritingReportWrite } from "../threads/writing-mode";
 import { isImageFile } from "../utils/files";
 
 import {
@@ -123,6 +124,11 @@ export function latestInFlightWriteFilePreview(
       if (!sourcePath) {
         continue;
       }
+      // Writing mode rewrites custom outputs/*.md to deep_research_report.
+      // Opening that filename would 404-poll until report.md lands.
+      if (isInterceptedWritingReportWrite(sourcePath, message.id, messages)) {
+        continue;
+      }
       // JSON (e.g. agentfx task-reports.json) is too large to live-preview:
       // switching the sandbox onto it freezes the main thread, then the rest
       // of the turn appears to dump at once. Keep showing markdown instead.

frontend-web/src/core/messages/utils-group.test.ts

@@ -56,6 +56,61 @@ test("write_file tool after 用户协助 opens a processing group instead of err
   ]);
 });
 
+test("writing-mode progress merges into the deep_research_report bar so the summary sits below", () => {
+  const types = groupTypes([
+    { type: "human", id: "h1", content: "写一篇论文" } as Message,
+    {
+      type: "ai",
+      id: "a1",
+      content: "",
+      tool_calls: [{ id: "c1", name: "deep_research_report", args: { query: "多智能体" } }],
+    } as Message,
+    {
+      type: "tool",
+      id: "t1",
+      name: "deep_research_report",
+      content: "ok",
+      tool_call_id: "c1",
+    } as Message,
+    {
+      type: "ai",
+      id: "progress",
+      content: "",
+      tool_calls: [
+        { id: "p1", name: "deep_research_progress", args: { label: "撰写研究报告", status: "complete" } },
+      ],
+    } as Message,
+    {
+      type: "ai",
+      id: "write",
+      content: "",
+      tool_calls: [{ id: "w1", name: "write_file", args: { path: "/mnt/user-data/outputs/report.md" } }],
+    } as Message,
+    {
+      type: "ai",
+      id: "summary",
+      content: "已生成多智能体论文，详见 report.md。",
+    } as Message,
+  ]);
+
+  assert.deepEqual(types, ["human", "assistant:processing", "assistant"]);
+});
+
+test("a lone deep-research progress bar still opens its own group", () => {
+  const types = groupTypes([
+    {
+      type: "ai",
+      id: "progress",
+      content: "",
+      tool_calls: [
+        { id: "p1", name: "deep_research_progress", args: { label: "撰写研究报告", status: "active" } },
+      ],
+    } as Message,
+  ]);
+
+  assert.deepEqual(types, ["assistant:processing"]);
+});
+
 test("tool messages still attach to an open processing group", () => {
   const types = groupTypes([
     {

frontend-web/src/core/messages/utils.ts

@@ -166,14 +166,19 @@ export function groupMessages<T>(
           messages: [message],
         });
       } else if (hasOnlyDeepResearchProgress(message)) {
-        // Each deep-research writing bar is its own group. Merging consecutive
-        // processing messages would pin a new report's in-progress steps onto
-        // the parent bar, which sits above the original file card.
-        groups.push({
-          id: message.id,
-          type: "assistant:processing",
-          messages: [message],
-        });
+        // 写作模式把进度条插在同一次 `deep_research_report` 之后，必须并进
+        // 当前 processing 组，总结才能排在整条步骤条下面。新一轮写作前面
+        // 会有 human/assistant 隔开，不会误并到上一轮的条上。
+        const lastGroup = groups[groups.length - 1];
+        if (lastGroup?.type === "assistant:processing" && groupHasDeepResearchReport(lastGroup)) {
+          lastGroup.messages.push(message);
+        } else {
+          groups.push({
+            id: message.id,
+            type: "assistant:processing",
+            messages: [message],
+          });
+        }
       } else if (hasSubagent(message)) {
         groups.push({
           id: message.id,
@@ -426,6 +431,14 @@ export function hasOnlyDeepResearchProgress(message: Message) {
   );
 }
 
+function groupHasDeepResearchReport(group: MessageGroup): boolean {
+  return group.messages.some(
+    (message) =>
+      message.type === "ai" &&
+      Boolean(message.tool_calls?.some((toolCall) => toolCall.name === "deep_research_report")),
+  );
+}
+
 export function isClarificationToolMessage(message: Message) {
   return message.type === "tool" && message.name === "ask_clarification";
 }

frontend-web/src/core/threads/use-research-report-stream.test.ts

@@ -6,6 +6,7 @@ import {
   buildResearchFeedMessages,
   buildResearchProgressToolCalls,
   buildResearchReportVirtualUrl,
+  composeResearchDisplayMessages,
   clearResearchReportStream,
   finalizeResearchReportStream,
   ingestResearchReportEvent,
@@ -148,6 +149,22 @@ test("progress tool calls reveal stages stepwise and mark interruption", () => {
   assert.equal(buildResearchProgressToolCalls(writing).length, 3);
   assert.equal(buildResearchProgressToolCalls(writing)[2].args.status, "active");
 
+  const completedByPhase = streamOf({ jobId: "j7b", phase: "done", reportText: "# x" });
+  const completedCalls = buildResearchProgressToolCalls(completedByPhase);
+  assert.equal(completedCalls.length, 3);
+  assert.ok(completedCalls.every((call) => call.args.status === "complete"));
+  assert.match(completedCalls[2].args.detail, /report\.md/);
+
+  const completedByStatus = streamOf({
+    jobId: "j7c",
+    phase: "writing",
+    status: "success",
+    reportText: "# x",
+  });
+  assert.ok(
+    buildResearchProgressToolCalls(completedByStatus).every((call) => call.args.status === "complete"),
+  );
+
   const failed = streamOf({ jobId: "j8", phase: "writing", status: "error", error: "模型超时" });
   const failedCalls = buildResearchProgressToolCalls(failed);
   assert.match(failedCalls.at(-1)?.args.label ?? "", /已中断/);
@@ -157,15 +174,73 @@ test("progress tool calls reveal stages stepwise and mark interruption", () => {
 test("feed messages attach the write_file stub only once report text exists", () => {
   const noText = streamOf({ jobId: "j9", phase: "collecting" });
   assert.equal(buildResearchFeedMessages(noText).length, 1);
-  assert.equal(buildResearchFeedMessages(noText)[0].tool_calls[0].name, "deep_research_progress");
+  assert.equal(buildResearchFeedMessages(noText)[0].tool_calls?.[0]?.name, "deep_research_progress");
+
+  const writingEmpty = streamOf({ jobId: "j9b", phase: "writing" });
+  assert.equal(buildResearchFeedMessages(writingEmpty).length, 1);
 
   const withText = streamOf({ jobId: "j10", phase: "writing", reportText: "# 报告正文" });
   const feed = buildResearchFeedMessages(withText);
   assert.equal(feed.length, 2);
-  const stub = feed[1].tool_calls[0];
-  assert.equal(stub.name, "write_file");
-  assert.equal(stub.args.path, "/mnt/user-data/outputs/report.md");
-  assert.equal(stub.args.content, "# 报告正文");
+  const stub = feed[1].tool_calls?.[0];
+  assert.equal(stub?.name, "write_file");
+  assert.equal(stub?.args.path, "/mnt/user-data/outputs/report.md");
+  assert.equal(stub?.args.content, "# 报告正文");
+
+  const done = streamOf({ jobId: "j10b", phase: "done", reportText: "# 报告正文" });
+  const doneFeed = buildResearchFeedMessages(done);
+  assert.equal(doneFeed.length, 3);
+  assert.equal(doneFeed[2].type, "tool");
+  assert.equal(doneFeed[2].tool_call_id, "research-report-j10b-write");
+});
+
+test("report_completed flips phase to done and write step completes before tool_finished", () => {
+  const tid = nextThread();
+  ingestAll(tid, [
+    { type: "report_delta", jobId: "jdone", payload: { delta: "正文", offset: 0 } },
+    { type: "report_completed", jobId: "jdone", payload: { sourceCount: 2 } },
+  ]);
+  const state = peekResearchReportStream(tid);
+  assert.equal(state?.phase, "done");
+  assert.equal(state?.status, "active");
+  const calls = buildResearchProgressToolCalls(state!);
+  assert.ok(calls.every((call) => call.args.status === "complete"));
+});
+
+test("composeResearchDisplayMessages inserts the bar before the summary and drops leaked prose", () => {
+  const feed = buildResearchFeedMessages(streamOf({
+    jobId: "jsplice",
+    phase: "done",
+    reportText: "# 报告",
+  }));
+  const composed = composeResearchDisplayMessages(
+    [
+      { id: "h", type: "human", content: "写论文" },
+      {
+        id: "ai-tool",
+        type: "ai",
+        content: "",
+        tool_calls: [{ id: "c1", name: "deep_research_report", args: {} }],
+      },
+      { id: "leak", type: "ai", content: "# 报告\n\n泄漏到消息列表的正文" },
+      { id: "tool", type: "tool", tool_call_id: "c1", content: "ok" },
+      { id: "summary", type: "ai", content: "已生成论文，详见 report.md。" },
+    ],
+    feed,
+  );
+
+  assert.deepEqual(
+    composed.map((message) => message.id),
+    [
+      "h",
+      "ai-tool",
+      "tool",
+      "research-progress-jsplice",
+      "research-report-jsplice",
+      "research-report-jsplice-write-result",
+      "summary",
+    ],
+  );
 });
 
 test("virtual URL matches the message-list ArtifactWriteToolCall URL (one suppression key)", () => {

frontend-web/src/core/threads/use-research-report-stream.ts

@@ -84,8 +84,8 @@ function getStore(threadId: string): StoreEntry {
  * 通知若逐帧发出，会让聊天页整棵树（长消息列表 + 沙箱 Markdown 预览）按
  * token 频率重渲染，页面直接卡死。工作台用 requestAnimationFrame 批处理
  * （DeepResearchWorkbench），聊天这里等效地按固定间隔合并——每秒最多
- * 10 次通知，流式观感不受影响。终态帧（tool_finished）与
- * finalize/clear 立即 flush，结束态不滞后。
+ * 10 次通知，流式观感不受影响。终态帧（tool_finished /
+ * report_completed）与 finalize/clear 立即 flush，结束态不滞后。
  */
 const EMIT_COALESCE_MS = 100;
 
@@ -193,7 +193,8 @@ export function ingestResearchReportEvent(threadId: string, frame: ResearchRepor
     case "report_completed":
       next = {
         ...base,
-        phase: "writing",
+        // 文件已落盘：步骤条应立刻标完成，不必等随后的 tool_finished。
+        phase: "done",
         sourceCount: typeof payload.sourceCount === "number" && payload.sourceCount > 0
           ? payload.sourceCount
           : base.sourceCount,
@@ -223,7 +224,7 @@ export function ingestResearchReportEvent(threadId: string, frame: ResearchRepor
   if (next !== previous) {
     store.state = next;
     // 状态同步更新（peek/快照立即可见）；通知按 token 帧频率合并，终态立即。
-    if (frame.type === "tool_finished") {
+    if (frame.type === "tool_finished" || frame.type === "report_completed") {
       emitNow(store);
     } else {
       emitCoalesced(store);
@@ -280,7 +281,11 @@ export type ResearchProgressToolCall = {
 export function buildResearchProgressToolCalls(state: ResearchReportStreamState): ResearchProgressToolCall[] {
   const rank = phaseRank(state.phase);
   const finished = state.status !== "active";
-  const effectiveRank = finished && state.status === "success" ? PHASE_ORDER.length - 1 : rank;
+  // success 时必须用 length（越过 write 的 boundary），length-1 永远完不成最后一步。
+  // report_completed 会先把 phase 置 done，此时工具可能还没返回，也视为写完。
+  const succeeded =
+    state.status === "success" || (state.status === "active" && state.phase === "done");
+  const effectiveRank = succeeded ? PHASE_ORDER.length : rank;
   const stages = [
     {
       id: "plan",
@@ -304,9 +309,11 @@ export function buildResearchProgressToolCalls(state: ResearchReportStreamState)
       id: "write",
       label: "撰写研究报告",
       boundary: PHASE_ORDER.length,
-      detail: state.reportText
-        ? "正在按「通用分析结构」逐字撰写，右侧沙箱同步预览"
-        : "正在整理资料并开始撰写报告",
+      detail: succeeded
+        ? "已按「通用分析结构」写完并保存为 report.md"
+        : state.reportText
+          ? "正在按「通用分析结构」逐字撰写，右侧沙箱同步预览"
+          : "正在整理资料并开始撰写报告",
     },
   ];
   const activeIndex = stages.findIndex((stage) => effectiveRank < stage.boundary);
@@ -330,19 +337,25 @@ export function buildResearchProgressToolCalls(state: ResearchReportStreamState)
 
 export type ResearchFeedMessage = {
   id: string;
-  type: "ai";
+  type: "ai" | "tool";
   content: string;
-  tool_calls: {
+  name?: string;
+  tool_call_id?: string;
+  tool_calls?: {
     id: string;
     name: string;
     args: Record<string, unknown>;
   }[];
 };
 
+function isResearchWriteFinished(state: ResearchReportStreamState): boolean {
+  return state.status === "success" || state.phase === "done";
+}
+
 /**
- * 组装聊天页要注入的两条虚拟 ai 消息：进度步骤条 + report.md 的 write_file
- * stub（沙箱 write-file 虚拟 URL 预览的数据源）。仅在报告尚无正文或仍在
- * 流式时输出 stub —— 完成后由真实 artifacts 接管。
+ * 组装聊天页要注入的虚拟消息：进度步骤条 + report.md 的 write_file stub
+ * （沙箱 write-file 虚拟 URL 预览的数据源）。写完后补一条 tool result，
+ * 让沙箱的「正在生成」立刻收起，不必等真实 artifacts 交接。
  */
 export function buildResearchFeedMessages(state: ResearchReportStreamState): ResearchFeedMessage[] {
   const messages: ResearchFeedMessage[] = [
@@ -353,23 +366,127 @@ export function buildResearchFeedMessages(state: ResearchReportStreamState): Res
       tool_calls: buildResearchProgressToolCalls(state),
     },
   ];
-  if (state.reportText.trim()) {
+  // 必须等正文首 token：思考阶段挂 stub 会提前显示「写入文件 report.md」。
+  if (!state.reportText.trim()) {
+    return messages;
+  }
+  const writeCallId = `research-report-${state.jobId}-write`;
+  messages.push({
+    id: `research-report-${state.jobId}`,
+    type: "ai",
+    content: "",
+    tool_calls: [
+      {
+        id: writeCallId,
+        name: "write_file",
+        args: { path: RESEARCH_REPORT_OUTPUT_PATH, content: state.reportText },
+      },
+    ],
+  });
+  if (isResearchWriteFinished(state)) {
     messages.push({
-      id: `research-report-${state.jobId}`,
-      type: "ai",
-      content: "",
-      tool_calls: [
-        {
-          id: `research-report-${state.jobId}-write`,
-          name: "write_file",
-          args: { path: RESEARCH_REPORT_OUTPUT_PATH, content: state.reportText },
-        },
-      ],
+      id: `research-report-${state.jobId}-write-result`,
+      type: "tool",
+      name: "write_file",
+      tool_call_id: writeCallId,
+      content: "ok",
     });
   }
   return messages;
 }
 
+function isDeepResearchReportAi(message: { type?: string; tool_calls?: Array<{ name?: string; id?: string }> }): boolean {
+  return (
+    message.type === "ai" &&
+    Boolean(message.tool_calls?.some((toolCall) => toolCall.name === "deep_research_report"))
+  );
+}
+
+function deepResearchReportCallIds(message: { tool_calls?: Array<{ name?: string; id?: string }> }): Set<string> {
+  return new Set(
+    (message.tool_calls ?? [])
+      .filter((toolCall) => toolCall.name === "deep_research_report" && toolCall.id)
+      .map((toolCall) => toolCall.id as string),
+  );
+}
+
+function messageHasVisibleText(message: { type?: string; content?: unknown; tool_calls?: unknown[] }): boolean {
+  if (message.type !== "ai") return false;
+  if (Array.isArray(message.tool_calls) && message.tool_calls.length > 0) return false;
+  return typeof message.content === "string" && message.content.trim().length > 0;
+}
+
+/**
+ * 丢掉管线内部 LLM 泄漏到父图 messages 流的正文：它们夹在
+ * `deep_research_report` 调用与其 tool result 之间，会让左侧气泡和沙箱一起写。
+ */
+export function omitLeakedReportTokens<T extends { type?: string; tool_calls?: Array<{ name?: string; id?: string }>; tool_call_id?: string; content?: unknown }>(
+  messages: T[],
+): T[] {
+  const hidden = new Set<number>();
+  let pendingIds: Set<string> | null = null;
+  for (let i = 0; i < messages.length; i++) {
+    const message = messages[i];
+    if (isDeepResearchReportAi(message)) {
+      pendingIds = deepResearchReportCallIds(message);
+      continue;
+    }
+    if (!pendingIds) continue;
+    if (
+      message.type === "tool" &&
+      typeof message.tool_call_id === "string" &&
+      pendingIds.has(message.tool_call_id)
+    ) {
+      pendingIds = null;
+      continue;
+    }
+    if (messageHasVisibleText(message)) {
+      hidden.add(i);
+    }
+  }
+  return hidden.size === 0 ? messages : messages.filter((_, index) => !hidden.has(index));
+}
+
+/**
+ * 把进度条 / write_file stub 插到 `deep_research_report` 及其结果之后、
+ * 模型总结之前，这样总结气泡永远在步骤条下面。
+ */
+export function insertResearchFeedMessages<T>(messages: T[], feed: T[]): T[] {
+  if (feed.length === 0) return messages;
+  let insertAt = -1;
+  let callIds = new Set<string>();
+  for (let i = 0; i < messages.length; i++) {
+    const message = messages[i] as { type?: string; tool_calls?: Array<{ name?: string; id?: string }> };
+    if (isDeepResearchReportAi(message)) {
+      insertAt = i + 1;
+      callIds = deepResearchReportCallIds(message);
+    }
+  }
+  if (insertAt === -1) {
+    return [...messages, ...feed];
+  }
+  while (insertAt < messages.length) {
+    const message = messages[insertAt] as { type?: string; tool_call_id?: string };
+    if (
+      message.type === "tool" &&
+      typeof message.tool_call_id === "string" &&
+      callIds.has(message.tool_call_id)
+    ) {
+      insertAt += 1;
+      continue;
+    }
+    break;
+  }
+  return [...messages.slice(0, insertAt), ...feed, ...messages.slice(insertAt)];
+}
+
+export function composeResearchDisplayMessages<T extends { type?: string; tool_calls?: Array<{ name?: string; id?: string }>; tool_call_id?: string; content?: unknown }>(
+  messages: T[],
+  feed: T[],
+): T[] {
+  return insertResearchFeedMessages(omitLeakedReportTokens(messages), feed);
+}
+
 /** write-file 虚拟 URL（ArtifactFileDetail 用它从 stub 消息读流式内容）。 */
 export function buildResearchReportVirtualUrl(state: ResearchReportStreamState): string {
   return new URL(

frontend-web/src/core/threads/use-research-writing-feed.ts

@@ -3,8 +3,8 @@
 /**
  * 聊天页「写作模式」深度研究进度注入。
  *
- * 把 `useResearchReportStream` 的流式状态转成 displayThread 尾部追加的
- * 虚拟消息（进度步骤条 + report.md 的 write_file stub）：
+ * 把 `useResearchReportStream` 的流式状态插到 `deep_research_report`
+ * 工具结果之后、模型总结之前（进度步骤条 + report.md 的 write_file stub）：
  *
  * - 进行中 / 中断：始终注入（中断态展示「已中断」，下一轮 jobId 变化自然淘汰）；
  * - 成功：注入到真实 report.md 产物落地为止（artifacts 出现该路径即撤出），
@@ -26,13 +26,16 @@ import {
   artifactPreviewKey,
   useArtifactsOptional,
 } from "@/components/workspace/artifacts/context";
+import { resolveWriteFilePath } from "@/core/artifacts/write-file-in-flight";
 
 import {
   buildResearchFeedMessages,
   buildResearchReportVirtualUrl,
+  composeResearchDisplayMessages,
   RESEARCH_REPORT_OUTPUT_PATH,
   useResearchReportStream,
 } from "./use-research-report-stream";
+import { isInterceptedWritingReportWrite } from "./writing-mode";
 
 type FeedThreadLike = {
   messages: Message[];
@@ -55,10 +58,15 @@ export function useResearchWritingFeed<T extends FeedThreadLike>(
     [thread.values?.artifacts],
   );
 
-  // 报告首帧正文到达且仍在写入 → 主动展开右侧沙箱并选中 write-file 虚拟
-  // 预览，报告在沙箱里边写边流式渲染。
+  // 正文首 token 到达且仍在写入 → 主动展开右侧沙箱。思考阶段不打开，
+  // 避免「写入文件 report.md」出现在模型还在想的时候。
   useEffect(() => {
-    if (!research || research.status !== "active" || !research.reportText.trim()) {
+    if (
+      !research ||
+      research.status !== "active" ||
+      research.phase !== "writing" ||
+      !research.reportText.trim()
+    ) {
       return;
     }
     if (autoOpenedJobRef.current === research.jobId) return;
@@ -77,7 +85,14 @@ export function useResearchWritingFeed<T extends FeedThreadLike>(
     if (!artifacts) return;
     handedOverJobRef.current = research.jobId;
     const current = artifacts.selectedArtifact;
-    if (current !== null && current !== buildResearchReportVirtualUrl(research)) {
+    const virtualUrl = buildResearchReportVirtualUrl(research);
+    const currentPath = current ? resolveWriteFilePath(current) : "";
+    const keepUserSelection =
+      current !== null &&
+      current !== virtualUrl &&
+      current !== RESEARCH_REPORT_OUTPUT_PATH &&
+      !isInterceptedWritingReportWrite(currentPath);
+    if (keepUserSelection) {
       return;
     }
     artifacts.select(RESEARCH_REPORT_OUTPUT_PATH);
@@ -91,11 +106,11 @@ export function useResearchWritingFeed<T extends FeedThreadLike>(
   }, [hasRealArtifact, research]);
 
   const displayThread = useMemo(() => {
-    if (feedMessages.length === 0) return thread;
-    const messages = [
-      ...thread.messages,
-      ...(feedMessages as unknown as Message[]),
-    ];
+    const messages = composeResearchDisplayMessages(
+      thread.messages,
+      feedMessages as unknown as Message[],
+    );
+    if (messages === thread.messages) return thread;
     return {
       ...thread,
       values: { ...thread.values, messages },

frontend-web/src/core/threads/writing-mode.test.ts

@@ -0,0 +1,101 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import {
+  isInterceptedWritingReportWrite,
+  isWritingFirstReportTurn,
+  shouldAutoOpenWritingArtifact,
+} from "./writing-mode";
+
+test("custom outputs markdown is always intercepted except the research stub", () => {
+  assert.equal(
+    isInterceptedWritingReportWrite("/mnt/user-data/outputs/paper.md"),
+    true,
+  );
+  assert.equal(
+    isInterceptedWritingReportWrite(
+      "/mnt/user-data/outputs/report.md",
+      "research-report-j1",
+    ),
+    false,
+  );
+});
+
+test("report.md is intercepted for the whole first-report turn", () => {
+  const beforePipeline = [{ type: "human", content: "写一篇论文" }];
+  assert.equal(isWritingFirstReportTurn(beforePipeline), true);
+  assert.equal(
+    isInterceptedWritingReportWrite(
+      "/mnt/user-data/outputs/report.md",
+      "m1",
+      beforePipeline,
+    ),
+    true,
+  );
+
+  const inFlight = [
+    { type: "human", content: "写一篇论文" },
+    {
+      type: "ai",
+      tool_calls: [{ name: "deep_research_report" }],
+    },
+  ];
+  assert.equal(isWritingFirstReportTurn(inFlight), true);
+  assert.equal(
+    isInterceptedWritingReportWrite("/mnt/user-data/outputs/report.md", "m2", inFlight),
+    true,
+  );
+
+  const succeeded = [
+    ...inFlight,
+    {
+      type: "tool",
+      name: "deep_research_report",
+      content: "研究报告已完成：已写入 report.md。",
+    },
+  ];
+  assert.equal(isWritingFirstReportTurn(succeeded), true);
+  assert.equal(
+    isInterceptedWritingReportWrite("/mnt/user-data/outputs/report.md", "m3", succeeded),
+    true,
+  );
+});
+
+test("sandbox auto-open waits for report.md on the first-report turn", () => {
+  const firstTurn = [
+    { type: "human", content: "写一篇论文" },
+    {
+      type: "ai",
+      tool_calls: [{ name: "deep_research_report" }],
+    },
+  ];
+  assert.equal(
+    shouldAutoOpenWritingArtifact("/mnt/user-data/outputs/research-notes.md", firstTurn),
+    false,
+  );
+  assert.equal(
+    shouldAutoOpenWritingArtifact("/mnt/user-data/outputs/report.md", firstTurn),
+    true,
+  );
+});
+
+test("a later user turn releases report.md live edits", () => {
+  const followUp = [
+    { type: "human", content: "写一篇论文" },
+    {
+      type: "ai",
+      tool_calls: [{ name: "deep_research_report" }],
+    },
+    {
+      type: "tool",
+      name: "deep_research_report",
+      content: "研究报告已完成：已写入 report.md。",
+    },
+    { type: "human", content: "把第二节改短一点" },
+  ];
+  assert.equal(isWritingFirstReportTurn(followUp), false);
+  assert.equal(
+    isInterceptedWritingReportWrite("/mnt/user-data/outputs/report.md", "m4", followUp),
+    false,
+  );
+});

frontend-web/src/core/threads/writing-mode.ts

@@ -0,0 +1,112 @@
+/** Only the writing-mode deliverable counts as a follow-up edit target. */
+
+const OUTPUTS_PREFIX = "/mnt/user-data/outputs";
+
+export function normalizeWritingPath(path: string | null | undefined): string {
+  if (!path) return "";
+  return path.replace(/\\/g, "/").split("?")[0]?.split("#")[0]?.replace(/\/+$/, "") ?? "";
+}
+
+export function isWritingModeReportPath(
+  path: string | null | undefined,
+): boolean {
+  const normalized = normalizeWritingPath(path);
+  return /(?:^|\/)report\.md$/i.test(normalized);
+}
+
+/** Markdown under the sandbox outputs dir — writing mode intercepts these as the report. */
+export function isOutputsMarkdownPath(path: string | null | undefined): boolean {
+  const normalized = normalizeWritingPath(path);
+  if (!normalized || !/\.(?:md|markdown)$/i.test(normalized)) return false;
+  return (
+    normalized === OUTPUTS_PREFIX ||
+    normalized.startsWith(`${OUTPUTS_PREFIX}/`) ||
+    normalized === "outputs" ||
+    normalized.startsWith("outputs/")
+  );
+}
+
+type WritingPipelineMessage = {
+  type?: string;
+  name?: string;
+  content?: unknown;
+  additional_kwargs?: Record<string, unknown>;
+  tool_calls?: Array<{ name?: string }>;
+};
+
+/**
+ * First-report turn: no successful pipeline yet, or the latest visible user
+ * message is still the one that triggered that pipeline. Follow-up edits
+ * (a later visible human after success) keep live `report.md` writes visible.
+ */
+export function isWritingFirstReportTurn(
+  messages: readonly WritingPipelineMessage[] | null | undefined,
+): boolean {
+  if (!messages?.length) return false;
+  let lastVisibleHuman = -1;
+  let lastSuccess = -1;
+  for (let index = 0; index < messages.length; index += 1) {
+    const message = messages[index];
+    if (
+      message?.type === "human" &&
+      message.additional_kwargs?.hide_from_ui !== true
+    ) {
+      lastVisibleHuman = index;
+    }
+    if (message?.type === "tool" && message.name === "deep_research_report") {
+      const content = typeof message.content === "string" ? message.content : "";
+      if (content && !content.toLowerCase().startsWith("error")) {
+        lastSuccess = index;
+      }
+    }
+  }
+  return lastVisibleHuman >= 0 && (lastSuccess < 0 || lastVisibleHuman <= lastSuccess);
+}
+
+/**
+ * Hand-written outputs/*.md writes the backend rewrites or drops:
+ * custom filenames always, and `report.md` while the first-turn pipeline is
+ * in-flight or just succeeded. The injected research stub stays visible.
+ */
+export function isInterceptedWritingReportWrite(
+  path: string | null | undefined,
+  messageId?: string | null,
+  messages?: readonly WritingPipelineMessage[] | null,
+): boolean {
+  if (typeof messageId === "string" && messageId.startsWith("research-report-")) {
+    return false;
+  }
+  if (!isOutputsMarkdownPath(path)) {
+    return false;
+  }
+  if (!isWritingModeReportPath(path)) {
+    return true;
+  }
+  return isWritingFirstReportTurn(messages);
+}
+
+/** Auto-open the sandbox only for the real report during the first-report turn. */
+export function shouldAutoOpenWritingArtifact(
+  path: string | null | undefined,
+  messages?: readonly WritingPipelineMessage[] | null,
+): boolean {
+  if (!path) {
+    return false;
+  }
+  if (isWritingFirstReportTurn(messages)) {
+    return isWritingModeReportPath(path);
+  }
+  return !isInterceptedWritingReportWrite(path, undefined, messages);
+}
+
+export function resolveWritingModeReportPath(
+  artifacts: readonly string[] | null | undefined,
+  selectedArtifact?: string | null,
+): string | undefined {
+  if (isWritingModeReportPath(selectedArtifact)) {
+    return selectedArtifact ?? undefined;
+  }
+  return [...(artifacts ?? [])]
+    .reverse()
+    .find((path) => isWritingModeReportPath(path));
+}

frontend-web/src/pages/AgentChatPage.tsx

@@ -45,6 +45,7 @@ import { stopActiveThreadBeforeClarificationReply, stopThreadRun, useThreadStrea
 import { useResearchWritingFeed } from "@/core/threads/use-research-writing-feed";
 import { clearResearchReportStream } from "@/core/threads/use-research-report-stream";
 import { textOfMessage } from "@/core/threads/utils";
+import { resolveWritingModeReportPath } from "@/core/threads/writing-mode";
 import { OptType, writeYLog } from "@/core/log/y-log";
 import {
   Select,
@@ -612,16 +613,13 @@ export default function AgentChatPage({
     } as typeof displayThread;
   }, [displayThread, showReportImportCard, taskId, threadId]);
 
-  // 写作模式续写轮：已有 md 产物（report.md 已生成）时回传 writing_artifact_path，
-  // 后端据此走「直接编辑画布」分支而不是再次挂载深度研究写报告管线（与
-  // ChatPage 的回传逻辑对齐）。
-  const writingArtifactPath = useMemo(() => {
-    const isMarkdown = (path: string | null | undefined) =>
-      !!path && /\.(md|markdown)(?:$|[?#])/i.test(path);
-    return [...(thread.values.artifacts ?? [])]
-      .reverse()
-      .find((path) => isMarkdown(path));
-  }, [thread.values.artifacts]);
+  // 写作模式续写轮：仅当已有写作模式产物 report.md 时回传 writing_artifact_path，
+  // 后端据此走「直接编辑画布」分支而不是再次挂载深度研究写报告管线。其它 leftover
+  // .md 不得跳过管线（与 ChatPage 对齐）。
+  const writingArtifactPath = useMemo(
+    () => resolveWritingModeReportPath(thread.values.artifacts),
+    [thread.values.artifacts],
+  );
 
   // ── 「模板数据转换器」对话页专属调试入口（仅此 agent）──────────────────────────
   // 选一个页面模板，问答跑完后点「渲染预览」：取最近一条 AI 回复里的 JSON 填进模板，

frontend-web/src/pages/ChatPage.tsx

@@ -63,6 +63,7 @@ import {
 import { useThreadStream, stopActiveThreadBeforeClarificationReply } from "@/core/threads/hooks";
 import { useResearchWritingFeed } from "@/core/threads/use-research-writing-feed";
 import { clearResearchReportStream } from "@/core/threads/use-research-report-stream";
+import { resolveWritingModeReportPath } from "@/core/threads/writing-mode";
 import { queueLlmWikiConversationDeposit } from "@/core/llmwiki/conversation-deposit";
 import { useSingleRoundRagMessages } from "@/core/threads/use-single-round-rag";
 import { useMultiRoundRagMessages } from "@/core/threads/use-multi-round-rag";
@@ -354,16 +355,11 @@ export default function ChatPage() {
     researchDisplayThread,
   ]);
 
-  const writingArtifactPath = useMemo(() => {
-    const isMarkdown = (path: string | null | undefined) =>
-      !!path && /\.(md|markdown)(?:$|[?#])/i.test(path);
-    if (isMarkdown(selectedArtifact)) {
-      return selectedArtifact ?? undefined;
-    }
-    return [...(thread.values.artifacts ?? [])]
-      .reverse()
-      .find((path) => isMarkdown(path));
-  }, [selectedArtifact, thread.values.artifacts]);
+  const writingArtifactPath = useMemo(
+    () =>
+      resolveWritingModeReportPath(thread.values.artifacts, selectedArtifact),
+    [selectedArtifact, thread.values.artifacts],
+  );
 
   const handleSubmit = useCallback(
     (message: PromptInputMessage) => {

frontend-web/src/pages/IframeChatPage.tsx

@@ -42,6 +42,7 @@ import {
 import { usePluginManagementSettings } from "@/core/system-settings/hooks";
 import { stopActiveThreadBeforeClarificationReply, useThreadStream } from "@/core/threads/hooks";
 import { textOfMessage } from "@/core/threads/utils";
+import { resolveWritingModeReportPath } from "@/core/threads/writing-mode";
 import { env } from "@/env";
 import { cn } from "@/lib/utils";
 import {
@@ -285,16 +286,11 @@ export default function IframeChatPage() {
     threadMetadataAgentId,
   ]);
 
-  const writingArtifactPath = useMemo(() => {
-    const isMarkdown = (path: string | null | undefined) =>
-      !!path && /\.(md|markdown)(?:$|[?#])/i.test(path);
-    if (isMarkdown(selectedArtifact)) {
-      return selectedArtifact ?? undefined;
-    }
-    return [...(thread.values.artifacts ?? [])]
-      .reverse()
-      .find((path) => isMarkdown(path));
-  }, [selectedArtifact, thread.values.artifacts]);
+  const writingArtifactPath = useMemo(
+    () =>
+      resolveWritingModeReportPath(thread.values.artifacts, selectedArtifact),
+    [selectedArtifact, thread.values.artifacts],
+  );
 
   const handleSubmit = useCallback(
     (