diff --git a/CHANGELOG.md b/CHANGELOG.md
index e1e65f03..5b7304d5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # 印度占星 Skill 更新日志
 
+## 2026-09-17 — 校正会话上不再出现可用的普通输入框
+
+在生时校正会话里，普通对话的输入框不再能用：打开校正面之前是禁用的「正在打开生时校正…」；打开失败时可以点「重新打开生时校正」。打在那里的字不会再发到普通咨询。Skill 版本不变。
+
 ## 2026-09-17 — 星盘页、星历页去掉三句说明
 
 打开星盘后，Tab 行下面不再写「主盘直接算 · 分盘按需 · 不消耗点数」。基础信息里也不再写「下面是词条式释义，不是对你个人的判断。」星历页底部不再写「这一页是天象本身，不是对你的判断。」盘还是主盘先算、分盘点到才算、不扣点；行星卡仍是度数和星宿；星历仍只写天象事实，不是运势判断。Skill 版本不变。
diff --git a/docs/BUG_HISTORY.md b/docs/BUG_HISTORY.md
index eda81136..f78a682b 100644
--- a/docs/BUG_HISTORY.md
+++ b/docs/BUG_HISTORY.md
@@ -12034,3 +12034,35 @@
 - 相关记录：BUG-214、BUG-286、BUG-922
 - 复发自：无
 - 修复版本：待发布
+
+## BUG-924 | 校正会话上普通输入框可用，问题发到 `/api/consult`
+
+- 状态：resolved
+- 首次发现：2026-09-17
+- 最近更新：2026-09-17
+- 影响面：`use-consultation-run.ts` `send()`、`page.tsx` 普通 `ChatComposer`、`use-session-management.ts` 回退路径
+- 用户现象：在生时校正会话里打了一个普通问题，请求打到咨询接口，提示「咨询会话不存在」。
+- 触发条件：校正会话已激活但校正面未开（刷新揭幕超时、打开失败不重试、删除或回退落到列表第一条校正会话）。
+- 根因：发送链路以「校正面没开」推断「当前是普通会话」；`send()` 不看 `sessionType`。BUG-505 只覆盖了 `selectSession`。
+- 修复：`send()` 对校正会话不发 `/api/consult`，保留草稿并打开校正面。普通输入框在校正会话上只有禁用态。删除 / popstate / `sessions[0]` 回退不再直接 `setActiveSessionId` 到校正会话。
+- 验证：`rectification-session-composer-guard.test.ts`、`rectification-surface-contract.test.ts`。
+- 防复发：校正会话不得发出 `/api/consult`；普通输入框在校正会话上不得可用。
+- 相关记录：BUG-505、BUG-925
+- 复发自：无
+- 修复版本：待发布
+
+## BUG-925 | 咨询接口把校正会话和「会话不存在」都回 404
+
+- 状态：resolved
+- 首次发现：2026-09-17
+- 最近更新：2026-09-17
+- 影响面：`api/consult/route.ts`、`use-consultation-run.ts` 错误映射
+- 用户现象：校正会话误发咨询时只看到「咨询会话不存在」。
+- 触发条件：`POST /api/consult` 的 `sessionId` 指向 `session_type !== consultation`。
+- 根因：查不到与类型不对共用一个 404。
+- 修复：查不到仍 404「咨询会话不存在」；类型不对 409 `session_not_consultation`。前端收到该码不显示错误、不扣点，改走打开校正面。
+- 验证：`chat-session-authority.test.ts`、`rectification-session-composer-guard.test.ts`。
+- 防复发：不得把两种失败再合成一个 404。
+- 相关记录：BUG-924
+- 复发自：无
+- 修复版本：待发布
diff --git a/docs/tasks/PROGRESS-rectification-session-composer-guard-20260917.md b/docs/tasks/PROGRESS-rectification-session-composer-guard-20260917.md
new file mode 100644
index 00000000..43b282aa
--- /dev/null
+++ b/docs/tasks/PROGRESS-rectification-session-composer-guard-20260917.md
@@ -0,0 +1,33 @@
+# PROGRESS · 校正会话输入框守卫（2026-09-17）
+
+工作树：`.worktrees/rectification-session-composer-guard-20260917`  
+分支：`codex/rectification-session-composer-guard-20260917`  
+基线：`origin/staging` @ `8eb1de1f`  
+本机 Windows。
+
+Skill **未 bump**。未改 Python、迁移、Skill、校正面组件、校正 Agent。
+
+## 任务状态
+
+| 任务 | 状态 | 说明 |
+| --- | --- | --- |
+| T1 send() 会话类型守卫 BUG-924 | 完成 | 校正会话不发 `/api/consult`，保留草稿，打开校正面；pending 指向校正会话则丢弃 |
+| T4 错误码 BUG-925 | 完成 | 查不到 404；类型不对 409 `session_not_consultation`；前端不显示错误、走 T1 |
+| T2 普通输入框禁用态 | 完成 | placeholder「正在打开生时校正…」；失败时「重新打开生时校正」 |
+| T3 回退走 selectSession | 完成 | `activateFallbackSession`；popstate 用 `fallbackSessionId`；`sessions[0]` 改为第一条非校正 |
+| T5 记录 | 完成 | BUG-924/925、CHANGELOG、DESIGN、VOICE、真人清单 |
+
+## 让步
+
+`/api/consult/cancel` 与 `status` 按 requestId 工作，没有 session_type 判断，未改。
+
+## 测试
+
+| 项 | 结果 |
+| --- | --- |
+| `tsc --noEmit` | 0 错 |
+| `npm run lint` | 0 error / 116 warning（与基线同；本轮文件 0 条） |
+| 定向 | composer-guard / surface-contract / chat-session-authority / bootstrap-reveal / home-shell-growth **34 passed / 0 failed** |
+| `page.tsx` 行数 | 开工 1835 → 现在 ≤ 1835 |
+
+无登录态、无 Chrome：走查见 `docs/testing/rectification-session-composer-guard-20260917.md`。
diff --git a/docs/tasks/README.md b/docs/tasks/README.md
index c8c9d6b0..2212ac2c 100644
--- a/docs/tasks/README.md
+++ b/docs/tasks/README.md
@@ -106,7 +106,7 @@
 | `TASK-rectification-dead-d9-choice-fix-20260916.md` | `PROGRESS-rectification-dead-d9-choice-fix-20260916.md` | **验收修复单**：自建分盘探针照 `withNakshatraBoundaryProbe` 模式在每个读 state 的地方（盖戳 / 答题 / `previousInferenceFromReceipt` / GET 投影 / idle 过期判定 / 计划承接）从 receipt 确定性重建（BUG-915）；测试改走生产路径、删手工塞探针的 fixture；顺带 host 前置挪到会话校验之后、登记 phase（BUG-916）；死卡不得配 `collect_waiting` 占位（BUG-917）；**产品决策 1c**：风格题默认不作全额计分（沿用 09-09 ±1 拍板），无事件探针就走下一条线。**staging 现状：风格题答不了，先跳过**。§1d 已记 **产品决策 (b)** | 已验收 | `5113d457`（BUG-915～917，产品拍板 (b) 风格题不计分）。Claude 独立验收：生产路径测试（receipt 不含自建探针）答题 applied / GET 出卡 / idle 不误伤；合并候选门禁 tsc 0 / lint 0 error / npm test 3427 条 31 红与基线逐条相同 / `/` Static / 首屏 gzip 620,107→620,193（+0.01%）/ pytest 63 绿 / 快速门 Python 798 绿。真机清单 `docs/testing/rectification-dead-d9-choice-fix-20260916.md` |
 | `TASK-rectification-mobile-timeline-readout-20260917.md` | `PROGRESS-rectification-mobile-timeline-readout-20260917.md` | 手机截图：时间轴读数第四项被裁成「已…」（nowrap + inset 内边距，BUG-918）；「跳到最新」浮层压住选项 C（BUG-919）。灰卡与「再说一件」矛盾归修复单 BUG-915/917 | 已验收 | `e8e98bbd`（合入时重放为本分支提交，BUG-918/919）。时间轴相关 71 条 + 全量同上；手机上隐藏「已对照 N 件」符合 DESIGN §10；桌面是否也移除待产品拍板。真机清单 `docs/testing/rectification-mobile-timeline-readout-20260917.md` |
 | `TASK-mobile-viewport-scroll-lock-20260917.md` | `PROGRESS-mobile-viewport-scroll-lock-20260917.md` | iPhone 上键盘收起 / 刷新后整页上移、顶栏点不到（BUG-920）：iOS 不支持 `interactive-widget`，键盘弹出时 Safari 滚动 window，`html/body overflow: hidden` 让用户拉不回来，reload 又还原 `scrollY`；代码里无任何 window 级复位。补 `ViewportScrollLock`（`scrollRestoration=manual` + `visualViewport` 复位）。与今天两单无关，既有缺陷。**T3 顶栏积分块「有点扁」（BUG-921）**：两枚芯片 44px 塞在 46px 顶栏里、字号/内边距/圆角各一套、积分块强制 64px 最小宽度；统一尺寸并把手机顶栏放到 52px | 待验收 | `codex/mobile-viewport-scroll-lock-20260917` |
-| `TASK-rectification-session-composer-guard-20260917.md` | — | 校正会话激活但校正面未开（刷新揭幕超时 / 打开失败不重试 / 删除与 popstate 回退落到列表第一条）时露出可用的普通输入框，问题发到 `/api/consult` 回 404「咨询会话不存在」；`send()` 无会话类型守卫；服务端无独立错误码。关联 BUG-505。BUG 段 924 起 | 待领取 | — |
+| `TASK-rectification-session-composer-guard-20260917.md` | `PROGRESS-rectification-session-composer-guard-20260917.md` | 校正会话激活但校正面未开（刷新揭幕超时 / 打开失败不重试 / 删除与 popstate 回退落到列表第一条）时露出可用的普通输入框，问题发到 `/api/consult` 回 404「咨询会话不存在」；`send()` 无会话类型守卫；服务端无独立错误码。关联 BUG-505。BUG 段 924 起 | 待验收 | `codex/rectification-session-composer-guard-20260917` |
 
 ### 聊天主链路与首页
 
diff --git a/docs/testing/rectification-session-composer-guard-20260917.md b/docs/testing/rectification-session-composer-guard-20260917.md
new file mode 100644
index 00000000..bca1fb13
--- /dev/null
+++ b/docs/testing/rectification-session-composer-guard-20260917.md
@@ -0,0 +1,24 @@
+# 真机清单 · 校正会话普通输入框守卫（2026-09-17）
+
+执行环境无登录态、无 Chrome。下列条目留给有真实账号的人在 staging 走查。截图不要带姓名、出生资料或会话正文。
+
+## 刷新后立刻打字
+
+1. 打开一条进行中的生时校正会话。
+2. 刷新页面。揭幕后立刻在底部输入框打字。
+3. **看：** 输入框是禁用的，占位「正在打开生时校正…」。没有转圈。
+4. 几秒后校正面出现。刚才打的字还在草稿里（不要发到普通咨询）。
+
+## 打开失败后重新打开
+
+1. 断网（或开发者工具离线）。
+2. 点侧栏一条校正会话。
+3. **看：** 错误文案 + 「重新打开生时校正」按钮。普通输入框仍禁用。
+4. 恢复网络，点按钮。
+5. **看：** 校正面打开。
+
+## 删除后落到校正会话
+
+1. 当前是一条普通对话，侧栏下一条（或第一条剩下的）是校正会话。
+2. 删除当前普通对话。
+3. **看：** 不会出现可用的普通输入框。要么打开校正面，要么输入框保持禁用。
diff --git a/frontend/DESIGN.md b/frontend/DESIGN.md
index 211b9208..9a894e4d 100644
--- a/frontend/DESIGN.md
+++ b/frontend/DESIGN.md
@@ -218,7 +218,7 @@ Radii have two visual steps. Controls use 8px (`--radius-md`; `--radius-xs` and
 
 - **Structure:** a column, not a row — warm canvas field on top, the composer's own bottom row beneath it. The row carries the model picker on the left and the send/stop control on the right, with the character count inline beside it.
 - **No strip below the composer.** `.composer-footer` used to sit under the field at a permanent `min-height: 44px`, holding the model picker and a count that only appears near the cap — so most of the time it was 44px of empty chrome on every screen. The row is inside the box now and only renders what it has.
-- **States:** default, hover, focus with deep-brown ring, disabled only for structural reasons (readonly, session loading, onboarding, the other surface open), invalid. Generating does not disable the textarea; the send control becomes stop.
+- **States:** default, hover, focus with deep-brown ring, disabled only for structural reasons (readonly, session loading, onboarding, the other surface open, **a rectification session whose surface is not yet open**), invalid. Generating does not disable the textarea; the send control becomes stop. On a rectification session the ordinary composer is only a disabled field with placeholder「正在打开生时校正…」; if opening failed, a「重新打开生时校正」button sits above it. No spinner.
 - **Queue:** one pending card (`.composer-queue`) sits above the field while an answer is in flight. Copy: “已排队，回答结束后发出”, plus the text and a 44px “撤回”. A second Enter appends to the same card with a newline. Successful settlement sends it; stop, failure, or recovery puts the text back in the field. The send button is disabled while a card is waiting. No spinner.
 - **Accessibility:** persistent label where practical; composer has an explicit accessible label.
 - **One composer:** the rectification surface renders the same `ChatComposer` as the main chat; there is no second composer. A surface that owns its own draft passes it as `value`; the main chat reads the draft store. Both count down from the same 500-character ceiling through `CharacterRemaining`, which the composer renders inline and only once `characterRemainingVisible()` is true — it no longer has a permanent container. Controls that belong to the composer go through the `toolbar` slot; nothing is stacked below it.
diff --git a/frontend/docs/VOICE.md b/frontend/docs/VOICE.md
index 40974467..85d68154 100644
--- a/frontend/docs/VOICE.md
+++ b/frontend/docs/VOICE.md
@@ -66,6 +66,7 @@ Jyotisha 的可见文案是产品的一部分。正确性红线（真实性、
 | 打开即有 / 直接计算 · 打开即有 · 不消耗点数 / 主盘直接算 · 分盘按需 · 不消耗点数 | （不写） | 星盘页不写成本、速度、计费说明。失败页也不写。忙（429）说「算盘的服务正忙，稍等几秒再打开就好。」；其它失败说「这张盘算不出来，我们已经记录下来了。」不要说「过一会儿再打开」。 |
 | 下面是词条式释义，不是对你个人的判断。 | （不写） | 基础信息 Tab 只放行星卡。词条本身不得写成运势，但不另印这句边界说明。 |
 | 这一页是天象本身，不是对你的判断。 | （不写） | 星历页只放日期、五要素、行运、九十天事件。「带这天去提问」在顶栏。不另印定性句。 |
+| （校正会话上普通输入框仍可打字） | 正在打开生时校正… | 校正会话上普通输入框只有禁用态。打开失败时按钮写「重新打开生时校正」。 |
 
 ## 服务端探针 → Agent 题干
 
diff --git a/frontend/src/app/api/consult/route.ts b/frontend/src/app/api/consult/route.ts
index f473b000..bdad37a5 100644
--- a/frontend/src/app/api/consult/route.ts
+++ b/frontend/src/app/api/consult/route.ts
@@ -305,12 +305,22 @@ export async function POST(request: Request) {
       { status: 503 },
     );
   }
-  if (!chatSession || chatSession.session_type !== "consultation") {
+  if (!chatSession) {
     return NextResponse.json(
       { error: "咨询会话不存在", message: "请重新进入咨询。" },
       { status: 404 },
     );
   }
+  if (chatSession.session_type !== "consultation") {
+    return NextResponse.json(
+      {
+        error: "这是生时校正会话",
+        code: "session_not_consultation",
+        message: "请在生时校正里继续。",
+      },
+      { status: 409 },
+    );
+  }
   if (!chatSession.model_id || chatSession.model_id !== parsed.data.modelId) {
     return NextResponse.json(
       { error: "会话模型已经变化", message: "请刷新会话后重新发送，本次不会扣点。" },
diff --git a/frontend/src/app/page.tsx b/frontend/src/app/page.tsx
index d72cc0c7..5bf12403 100644
--- a/frontend/src/app/page.tsx
+++ b/frontend/src/app/page.tsx
@@ -21,6 +21,11 @@ import {
   rectificationEntryLabels,
   resolveRectificationEntryAction,
 } from "@/lib/rectification-entry";
+import {
+  dropRectificationStoredPending,
+  ordinaryComposerPlaceholder,
+  rectificationOrdinaryComposerReopen,
+} from "@/lib/rectification-session-composer-guard";
 import { ConversationalBirthTimeRectification } from "@/components/conversational-birth-time-rectification";
 import {
   declaredBirthTime,
@@ -34,6 +39,7 @@ import { ChatTranscript, type ChatTranscriptActions } from "@/components/chat-tr
 import { ModelSelector } from "@/components/model-selector";
 import { OnboardingRedeemPaywall } from "@/components/onboarding-redeem-paywall";
 import { ChatComposer } from "@/components/chat-composer";
+import { RectificationComposerReopen } from "@/components/rectification-composer-reopen";
 import { JumpToLatestButton } from "@/components/jump-to-latest-button";
 import { SidebarInset, SidebarProvider, SidebarTrigger } from "@/components/ui/sidebar";
 import { composerDraftSnapshot, setComposerDraft } from "@/lib/composer-draft";
@@ -166,7 +172,6 @@ import {
   type Profile,
   type ReplyOutcome,
   type RequestError,
-  type StoredPendingConsultation,
   type StreamingReply,
   type Theme,
 } from "@/lib/home-types";
@@ -376,10 +381,12 @@ export default function Home() {
     onEditBirthTimeDetails: () => editDeclaredBirthTimeDetails(),
   });
 
-  const activeSession = sessions.find((session) => session.id === activeSessionId) ?? sessions[0];
+  const activeSession = sessions.find((session) => session.id === activeSessionId)
+    ?? sessions.find((session) => session.sessionType !== "birth_time_rectification");
   const activeRectificationSession = activeSession?.sessionType === "birth_time_rectification";
-  const rectificationSurfaceOpen = activeRectificationSession
-    && activeSession.id === rectificationSessionId;
+  const rectificationSurfaceOpen = Boolean(activeRectificationSession && activeSession && activeSession.id === rectificationSessionId);
+  const rectificationComposerLocked = Boolean(activeRectificationSession && !rectificationSurfaceOpen);
+  const rectificationComposerReopen = rectificationOrdinaryComposerReopen({ activeRectificationSession, error: rectificationError, errorSessionId: rectificationErrorSessionId, sessionId: activeSession?.id });
   const activeError = requestError && requestError.sessionId === activeSession?.id ? requestError.message : "";
   const isLoading = pendingSessionId === activeSession?.id;
   const productEntrypointsDisabled = !hydrated
@@ -460,10 +467,8 @@ export default function Home() {
   });
 
   const {
-    setRectificationHeaderSlot,
-    rectificationPanel,
-    resumeRectificationSession,
-    openRectificationFromHomepage,
+    setRectificationHeaderSlot, rectificationPanel, resumeRectificationSession,
+    openRectificationFromHomepage, openRectificationSession, reopenRectificationSession,
   } = useRectificationSurface({
     account, activeChartId, activeSessionIdRef, chartLibrary, creatingSession, modelCatalog,
     persistSession, profile, rectification, setRectification,
@@ -699,7 +704,7 @@ export default function Home() {
     && presetMessageFinished
     && !rectificationSurfaceOpen
     && Boolean(activeSession?.messagesHydrated)
-    && !activeSession.messages.length;
+    && !activeSession?.messages.length;
   const sessionMessagesLoading = Boolean(
     activeSession
     && activeSession.sessionType === "consultation"
@@ -766,8 +771,7 @@ export default function Home() {
     startNewChat,
     continueInNewChat,
     refreshAccount,
-    openAccountDialog,
-    openRectificationFromHomepage,
+    openAccountDialog, openRectificationFromHomepage, openRectificationSession,
   });
   const jumpToLatestVisible = !rectificationSurfaceOpen
     && !starterHomeVisible
@@ -939,13 +943,11 @@ export default function Home() {
         nextSessions = applyLegacySessionControls(nextAccount.user.id, nextSessions);
 
         let reservedConsultation: ConsultationStatus | null = null;
-        const storedPending: StoredPendingConsultation | null = readStoredPendingConsultation(
-          sessionStorage.getItem(pendingConsultationStorageKey),
-          nextSessions.map((session) => session.id),
+        const storedPending = dropRectificationStoredPending(
+          readStoredPendingConsultation(sessionStorage.getItem(pendingConsultationStorageKey), nextSessions.map((session) => session.id)),
+          nextSessions,
         );
-        if (!storedPending && sessionStorage.getItem(pendingConsultationStorageKey)) {
-          sessionStorage.removeItem(pendingConsultationStorageKey);
-        }
+        if (!storedPending) sessionStorage.removeItem(pendingConsultationStorageKey);
 
         if (storedPending) {
           try {
@@ -1747,22 +1749,15 @@ export default function Home() {
           {jumpToLatestVisible && (
             <JumpToLatestButton onClick={conversationAnchor.anchorToLatest} />
           )}
+          {rectificationComposerReopen && activeSession ? <RectificationComposerReopen message={rectificationErrorMessage} onReopen={() => void reopenRectificationSession(activeSession.id)} /> : null}
           <ChatComposer
             inputRef={composerInput}
             inputLabel={!profileComplete && onboardingStep === "name" ? "输入你的称呼" : "输入你的问题"}
-            placeholder={!account
-              ? "正在读取账户…"
-              : !profileComplete
-                ? onboardingStep === "name"
-                  ? presetMessageFinished ? "输入你的称呼" : "Jyotisha 正在输入…"
-                  : "请先完成上方资料"
-                : account.credits === 0 && !account.activeSubscription
-                  ? "余额不足，可在账户与点数中补充"
-                  : "例如：未来半年是否适合换工作？"}
+            placeholder={ordinaryComposerPlaceholder({ locked: rectificationComposerLocked, hasAccount: Boolean(account), profileComplete, onboardingName: onboardingStep === "name", presetMessageFinished, creditsEmpty: Boolean(account && account.credits === 0 && !account.activeSubscription) })}
             maxLength={!profileComplete && onboardingStep === "name" ? 80 : 500}
-            inputDisabled={sessionMessagesLoading || rectificationSurfaceOpen || (!profileComplete && (onboardingStep !== "name" || !presetMessageFinished || profileSaving))}
+            inputDisabled={sessionMessagesLoading || rectificationSurfaceOpen || activeRectificationSession || (!profileComplete && (onboardingStep !== "name" || !presetMessageFinished || profileSaving))}
             submitLabel={!profileComplete && onboardingStep === "name" ? "确认称呼" : "发送"}
-            submitBlocked={Boolean(pendingSessionId) || Boolean(queuedDraft) || sessionMessagesLoading || rectificationSurfaceOpen || !account || !modelCatalog || (!profileComplete && (onboardingStep !== "name" || !presetMessageFinished || profileSaving))}
+            submitBlocked={Boolean(pendingSessionId) || Boolean(queuedDraft) || sessionMessagesLoading || rectificationSurfaceOpen || activeRectificationSession || !account || !modelCatalog || (!profileComplete && (onboardingStep !== "name" || !presetMessageFinished || profileSaving))}
             stopVisible={isLoading}
             stopLabel={consultationPhase === "undo" ? "撤回发送，本次不扣点" : activeStreamingText ? "停止回答，保留已生成内容并退回本次点数" : "停止回答并申请退回本次点数"}
             stopTitle={consultationPhase === "undo" ? "撤回发送，本次不扣点" : activeStreamingText ? "停止回答，保留现有内容并申请退回本次点数" : "停止回答"}
diff --git a/frontend/src/components/rectification-composer-reopen.tsx b/frontend/src/components/rectification-composer-reopen.tsx
new file mode 100644
index 00000000..247dacdb
--- /dev/null
+++ b/frontend/src/components/rectification-composer-reopen.tsx
@@ -0,0 +1,18 @@
+import { RECTIFICATION_REOPEN_LABEL } from "@/lib/rectification-session-composer-guard";
+
+export function RectificationComposerReopen({
+  message,
+  onReopen,
+}: {
+  message: string;
+  onReopen: () => void;
+}) {
+  return (
+    <div className="error-message" role="alert">
+      <p>{message}</p>
+      <button type="button" className="button-secondary" onClick={onReopen}>
+        {RECTIFICATION_REOPEN_LABEL}
+      </button>
+    </div>
+  );
+}
diff --git a/frontend/src/hooks/use-consultation-run.ts b/frontend/src/hooks/use-consultation-run.ts
index ec0aa22f..f3f65e1b 100644
--- a/frontend/src/hooks/use-consultation-run.ts
+++ b/frontend/src/hooks/use-consultation-run.ts
@@ -62,6 +62,10 @@ import {
 } from "@/lib/home-cloud-sync";
 import { completedOnboardingTranscript, isProfileComplete, selectedBirthPlace } from "@/lib/home-profile";
 import { pendingConsultationStorageKey, timestamp } from "@/lib/home-types";
+import {
+  consultSendBlockedByRectificationSession,
+  SESSION_NOT_CONSULTATION_CODE,
+} from "@/lib/rectification-session-composer-guard";
 import type {
   Account,
   AccountDialog,
@@ -139,6 +143,7 @@ export type ConsultationRunParams = {
   refreshAccount: () => Promise<void>;
   openAccountDialog: (dialog: AccountDialog, options?: HTMLButtonElement | null | OpenAccountDialogOptions) => void;
   openRectificationFromHomepage: (pendingConsultationQuestion?: string | null) => Promise<void>;
+  openRectificationSession: (exactSessionId: string) => Promise<void> | void;
 };
 
 export function useConsultationRun(params: ConsultationRunParams) {
@@ -196,6 +201,7 @@ export function useConsultationRun(params: ConsultationRunParams) {
     refreshAccount,
     openAccountDialog,
     openRectificationFromHomepage,
+    openRectificationSession,
   } = params;
   const queued = useQueuedMessage();
 
@@ -219,6 +225,14 @@ export function useConsultationRun(params: ConsultationRunParams) {
     if (pendingConsultation.current) return;
     const lastMessage = session.messages.at(-1);
     const storedQuestion = stored?.question?.trim() ?? "";
+    if (consultSendBlockedByRectificationSession(session)) {
+      try {
+        sessionStorage.removeItem(pendingConsultationStorageKey);
+      } catch {
+        // Private-mode storage must not block recovery.
+      }
+      return;
+    }
     const lastIsQuestion = lastMessage?.role === "user"
       && (!storedQuestion || lastMessage.text === storedQuestion);
     const question = lastIsQuestion && lastMessage ? lastMessage.text : storedQuestion;
@@ -499,6 +513,26 @@ export function useConsultationRun(params: ConsultationRunParams) {
       : activeSession;
     const currentSession = options.sessionOverride ?? liveSession;
     if (!question || !currentSession || !modelCatalog || !account) return false;
+    if (consultSendBlockedByRectificationSession(currentSession)) {
+      if (resuming) {
+        pendingConsultation.current = null;
+        setPendingSessionId(null);
+        setPendingRequestId(null);
+        setConsultationPhase(null);
+        setStreamingReply(null);
+        try {
+          sessionStorage.removeItem(pendingConsultationStorageKey);
+        } catch {
+          // Private-mode storage must not block the guard.
+        }
+      }
+      setDraft(originalQuestion);
+      setDraftTheme(null);
+      setDraftEntrypoint(null);
+      await openRectificationSession(currentSession.id);
+      setDraft(originalQuestion);
+      return false;
+    }
     const rollbackSession = options.restoreOnFailure ?? liveSession ?? currentSession;
     if (!resuming && (pendingSessionId || cancellationInFlight.current || pendingConsultation.current)) return false;
     if (resuming) {
@@ -960,6 +994,17 @@ export function useConsultationRun(params: ConsultationRunParams) {
       const ownsInterface = pendingConsultation.current?.requestId === requestId;
       const partialReply = latestPartialReply;
       if (!cancelled && ownsInterface && pendingConsultation.current && caught instanceof ConsultationResponseError) {
+        if (caught.code === SESSION_NOT_CONSULTATION_CODE) {
+          updateSession(sessionId, () => rollbackSession);
+          setOnboardingJustCompleted(previousOnboardingState);
+          completeConsultationInterface(requestId);
+          setDraft(originalQuestion);
+          setDraftTheme(null);
+          setDraftEntrypoint(null);
+          await openRectificationSession(currentSession.id);
+          setDraft(originalQuestion);
+          return false;
+        }
         if (caught.code === "session_full") {
           updateSession(sessionId, () => rollbackSession);
           setOnboardingJustCompleted(previousOnboardingState);
diff --git a/frontend/src/hooks/use-rectification-surface.ts b/frontend/src/hooks/use-rectification-surface.ts
index ea1b4af7..f8cc3678 100644
--- a/frontend/src/hooks/use-rectification-surface.ts
+++ b/frontend/src/hooks/use-rectification-surface.ts
@@ -335,6 +335,12 @@ export function useRectificationSurface(params: RectificationSurfaceParams) {
     await openRectificationCase("session", exactSessionId, null);
   }
 
+  async function reopenRectificationSession(exactSessionId: string) {
+    setRectificationError("");
+    setRectificationErrorSessionId(null);
+    await openRectificationSession(exactSessionId);
+  }
+
   async function startNewRectification() {
     await openRectificationCase("new", null, null);
   }
@@ -404,6 +410,7 @@ export function useRectificationSurface(params: RectificationSurfaceParams) {
     openRectificationCase,
     openRectificationFromHomepage,
     openRectificationSession,
+    reopenRectificationSession,
     startNewRectification,
     handleRectificationProfileIncomplete,
     handleRectificationMessagesChange,
diff --git a/frontend/src/hooks/use-session-management.ts b/frontend/src/hooks/use-session-management.ts
index fc19b6ba..da129656 100644
--- a/frontend/src/hooks/use-session-management.ts
+++ b/frontend/src/hooks/use-session-management.ts
@@ -12,6 +12,7 @@ import {
   writeSessionUrl,
 } from "@/lib/chat-session-url";
 import { consultationReportMarkdown } from "@/lib/consultation-report-export";
+import { fallbackSessionId } from "@/lib/rectification-session-composer-guard";
 import { sortSessions } from "@/lib/session-groups";
 import { invalidateSidebarCache } from "@/lib/sidebar-data-cache";
 import {
@@ -235,9 +236,7 @@ export function useSessionManagement(params: SessionManagementParams) {
     setSessions(nextSessions);
     setBirthTimeConsultationConsent((current) => clearBirthTimeConsultationConsent(current, session.id));
     if (activeSessionId === session.id) {
-      const fallbackId = nextSessions[0]?.id ?? "";
-      setActiveSessionId(fallbackId);
-      if (!uiPreview.current) writeSessionUrl(fallbackId || null, "replace");
+      activateFallbackSession(nextSessions);
     }
     try {
       const response = await fetch(`/api/sessions/${encodeURIComponent(session.id)}`, { method: "DELETE" });
@@ -269,9 +268,7 @@ export function useSessionManagement(params: SessionManagementParams) {
     const nextArchivedAt = restoring ? null : new Date().toISOString();
     updateSession(sessionId, (current) => ({ ...current, archivedAt: nextArchivedAt }));
     if (!restoring && activeSessionId === sessionId) {
-      const fallbackId = visibleSessions.find((item) => item.id !== sessionId)?.id ?? "";
-      setActiveSessionId(fallbackId);
-      if (!uiPreview.current) writeSessionUrl(fallbackId || null, "replace");
+      activateFallbackSession(visibleSessions.filter((item) => item.id !== sessionId));
     }
     setComposerNotice(restoring ? "已恢复到聊天记录。" : "已归档，可在左侧归档中恢复。");
     void writeChatSession(sessionId, { archived_at: nextArchivedAt }, "update").then(invalidateSidebarCache).catch((caught) => {
@@ -392,6 +389,22 @@ export function useSessionManagement(params: SessionManagementParams) {
     sessionSelectionSource.current = "user";
   }
 
+  function activateFallbackSession(candidates: ChatSession[]) {
+    const fallbackId = fallbackSessionId(candidates);
+    if (!fallbackId) {
+      setActiveSessionId("");
+      if (!uiPreview.current) writeSessionUrl(null, "replace");
+      return;
+    }
+    const fallback = candidates.find((session) => session.id === fallbackId);
+    if (fallback?.sessionType === "birth_time_rectification") {
+      selectSession(fallbackId);
+      return;
+    }
+    setActiveSessionId(fallbackId);
+    if (!uiPreview.current) writeSessionUrl(fallbackId, "replace");
+  }
+
   async function loadMoreSessions() {
     if (!beginSessionPageLoad(loadMoreInFlight, sessionsCursor)) return;
     try {
@@ -431,7 +444,7 @@ export function useSessionManagement(params: SessionManagementParams) {
     if (uiPreview.current) return;
     const listed = sessionsRef.current;
     const query = parseSessionUrlQuery(search);
-    const fallbackId = listed[0]?.id ?? "";
+    const fallbackId = fallbackSessionId(listed);
     const requestedId = query.sessionId;
     if (query.present && !requestedId) {
       writeSessionUrl(null, "replace");
diff --git a/frontend/src/lib/rectification-session-composer-guard.ts b/frontend/src/lib/rectification-session-composer-guard.ts
new file mode 100644
index 00000000..da5a8196
--- /dev/null
+++ b/frontend/src/lib/rectification-session-composer-guard.ts
@@ -0,0 +1,67 @@
+export const RECTIFICATION_OPENING_COMPOSER_PLACEHOLDER = "正在打开生时校正…";
+export const RECTIFICATION_REOPEN_LABEL = "重新打开生时校正";
+export const SESSION_NOT_CONSULTATION_CODE = "session_not_consultation";
+
+export function isRectificationChatSession(
+  session: { sessionType?: string } | null | undefined,
+): boolean {
+  return session?.sessionType === "birth_time_rectification";
+}
+
+/** First non-rectification session, else the first session, else empty. */
+export function fallbackSessionId<T extends { id: string; sessionType: string }>(
+  sessions: readonly T[],
+): string {
+  return sessions.find((session) => session.sessionType !== "birth_time_rectification")?.id
+    ?? sessions[0]?.id
+    ?? "";
+}
+
+export function consultSendBlockedByRectificationSession(
+  session: { sessionType?: string } | null | undefined,
+): boolean {
+  return isRectificationChatSession(session);
+}
+
+export function dropRectificationStoredPending<
+  S extends { sessionId: string },
+  T extends { id: string; sessionType: string },
+>(
+  stored: S | null,
+  sessions: readonly T[],
+): S | null {
+  if (!stored) return null;
+  const session = sessions.find((item) => item.id === stored.sessionId);
+  if (session?.sessionType === "birth_time_rectification") return null;
+  return stored;
+}
+
+export function ordinaryComposerPlaceholder(input: {
+  locked: boolean;
+  hasAccount: boolean;
+  profileComplete: boolean;
+  onboardingName: boolean;
+  presetMessageFinished: boolean;
+  creditsEmpty: boolean;
+}): string {
+  if (input.locked) return RECTIFICATION_OPENING_COMPOSER_PLACEHOLDER;
+  if (!input.hasAccount) return "正在读取账户…";
+  if (!input.profileComplete) {
+    if (!input.onboardingName) return "请先完成上方资料";
+    return input.presetMessageFinished ? "输入你的称呼" : "Jyotisha 正在输入…";
+  }
+  if (input.creditsEmpty) return "余额不足，可在账户与点数中补充";
+  return "例如：未来半年是否适合换工作？";
+}
+
+export function rectificationOrdinaryComposerReopen(input: {
+  activeRectificationSession: boolean;
+  error: string;
+  errorSessionId: string | null;
+  sessionId: string | undefined;
+}): boolean {
+  if (!input.activeRectificationSession || !input.error || input.error === "profile_incomplete") {
+    return false;
+  }
+  return !input.errorSessionId || input.errorSessionId === input.sessionId;
+}
diff --git a/frontend/tests/chat-session-authority.test.ts b/frontend/tests/chat-session-authority.test.ts
index 1f7efd51..bc196527 100644
--- a/frontend/tests/chat-session-authority.test.ts
+++ b/frontend/tests/chat-session-authority.test.ts
@@ -35,6 +35,19 @@ test("session list GET omits messages while detail GET returns them", () => {
   assert.match(page, /messagesHydrated: messagesPresent/);
 });
 
+test("consult POST on a rectification session is 409, a missing id is 404", () => {
+  // 原值：!chatSession || session_type !== consultation 一律 404「咨询会话不存在」
+  // 新值：查不到 404；类型不对 409 session_not_consultation
+  // 原因：BUG-925 前端无法区分不存在与类型不对
+  assert.match(consultRoute, /if \(!chatSession\) \{[\s\S]*status: 404/);
+  assert.match(consultRoute, /code: "session_not_consultation"/);
+  assert.match(consultRoute, /status: 409/);
+  assert.doesNotMatch(
+    consultRoute,
+    /if \(!chatSession \|\| chatSession\.session_type !== "consultation"\)/,
+  );
+});
+
 test("consult reads stored history and never applies the client history field", () => {
   assert.match(consultRoute, /history: z\s*\.array\([\s\S]*?\)\s*\.max\(20\)\s*\.optional\(\)\s*\.default\(\[\]\)/);
   assert.match(consultRoute, /const storedHistory = historyWindow\.tail/);
diff --git a/frontend/tests/rectification-session-composer-guard.test.ts b/frontend/tests/rectification-session-composer-guard.test.ts
new file mode 100644
index 00000000..c8ff0825
--- /dev/null
+++ b/frontend/tests/rectification-session-composer-guard.test.ts
@@ -0,0 +1,106 @@
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import test from "node:test";
+
+import { homeSurface as page } from "./home-surface.ts";
+import {
+  consultSendBlockedByRectificationSession,
+  dropRectificationStoredPending,
+  fallbackSessionId,
+  RECTIFICATION_OPENING_COMPOSER_PLACEHOLDER,
+  RECTIFICATION_REOPEN_LABEL,
+  rectificationOrdinaryComposerReopen,
+  SESSION_NOT_CONSULTATION_CODE,
+} from "../src/lib/rectification-session-composer-guard.ts";
+
+const read = (relativePath: string) => readFileSync(new URL(relativePath, import.meta.url), "utf8");
+const run = read("../src/hooks/use-consultation-run.ts");
+const sessions = read("../src/hooks/use-session-management.ts");
+const consultRoute = read("../src/app/api/consult/route.ts");
+const pageSource = read("../src/app/page.tsx");
+const sendFn = run.slice(run.indexOf("async function send("), run.indexOf('await fetch("/api/consult"'));
+
+test("a rectification session blocks consult send and keeps the draft", () => {
+  assert.equal(consultSendBlockedByRectificationSession({ sessionType: "birth_time_rectification" }), true);
+  assert.equal(consultSendBlockedByRectificationSession({ sessionType: "consultation" }), false);
+  assert.match(sendFn, /consultSendBlockedByRectificationSession\(currentSession\)/);
+  assert.match(sendFn, /setDraft\(originalQuestion\)/);
+  assert.match(sendFn, /openRectificationSession\(currentSession\.id\)/);
+  assert.doesNotMatch(sendFn, /fetch\("\/api\/consult"/);
+});
+
+test("pending consult replay pointing at a rectification session is dropped", () => {
+  assert.equal(
+    dropRectificationStoredPending(
+      { sessionId: "r1" },
+      [{ id: "r1", sessionType: "birth_time_rectification" }],
+    ),
+    null,
+  );
+  assert.deepEqual(
+    dropRectificationStoredPending(
+      { sessionId: "c1" },
+      [{ id: "c1", sessionType: "consultation" }],
+    ),
+    { sessionId: "c1" },
+  );
+  assert.match(run, /if \(consultSendBlockedByRectificationSession\(session\)\) \{[\s\S]*sessionStorage\.removeItem\(pendingConsultationStorageKey\)/);
+});
+
+test("consult POST splits missing session from wrong session type", () => {
+  assert.match(consultRoute, /if \(!chatSession\) \{[\s\S]*咨询会话不存在[\s\S]*status: 404/);
+  assert.match(
+    consultRoute,
+    /if \(chatSession\.session_type !== "consultation"\) \{[\s\S]*session_not_consultation[\s\S]*status: 409/,
+  );
+  assert.match(consultRoute, /这是生时校正会话/);
+  assert.match(consultRoute, /请在生时校正里继续。/);
+  assert.equal(SESSION_NOT_CONSULTATION_CODE, "session_not_consultation");
+  assert.match(run, /caught\.code === SESSION_NOT_CONSULTATION_CODE/);
+});
+
+test("ordinary composer is locked on a rectification session until the surface opens", () => {
+  assert.equal(RECTIFICATION_OPENING_COMPOSER_PLACEHOLDER, "正在打开生时校正…");
+  assert.equal(RECTIFICATION_REOPEN_LABEL, "重新打开生时校正");
+  assert.match(pageSource, /inputDisabled=\{[^}]*activeRectificationSession/);
+  assert.match(pageSource, /submitBlocked=\{[^}]*activeRectificationSession/);
+  assert.match(pageSource, /ordinaryComposerPlaceholder\(/);
+  assert.match(pageSource, /RectificationComposerReopen/);
+  assert.equal(
+    rectificationOrdinaryComposerReopen({
+      activeRectificationSession: true,
+      error: "生时校正会话暂时无法打开，请稍后重试。",
+      errorSessionId: "s1",
+      sessionId: "s1",
+    }),
+    true,
+  );
+  assert.equal(
+    rectificationOrdinaryComposerReopen({
+      activeRectificationSession: true,
+      error: "",
+      errorSessionId: null,
+      sessionId: "s1",
+    }),
+    false,
+  );
+});
+
+test("delete and popstate fallbacks do not setActiveSessionId onto a rectification session", () => {
+  assert.equal(
+    fallbackSessionId([
+      { id: "r1", sessionType: "birth_time_rectification" },
+      { id: "c1", sessionType: "consultation" },
+    ]),
+    "c1",
+  );
+  assert.equal(
+    fallbackSessionId([{ id: "r1", sessionType: "birth_time_rectification" }]),
+    "r1",
+  );
+  assert.match(sessions, /function activateFallbackSession/);
+  assert.match(sessions, /if \(fallback\?\.sessionType === "birth_time_rectification"\) \{\s*selectSession\(fallbackId\);/);
+  assert.match(sessions, /if \(activeSessionId === session.id\) \{\s*activateFallbackSession\(nextSessions\);/);
+  assert.match(sessions, /const fallbackId = fallbackSessionId\(listed\);/);
+  assert.match(page, /sessions.find\(\(session\) => session.sessionType !== "birth_time_rectification"\)/);
+});
diff --git a/frontend/tests/rectification-surface-contract.test.ts b/frontend/tests/rectification-surface-contract.test.ts
index ea7b7036..c12d1676 100644
--- a/frontend/tests/rectification-surface-contract.test.ts
+++ b/frontend/tests/rectification-surface-contract.test.ts
@@ -65,6 +65,17 @@ test("a rectification session named in the URL is hydrated before the reveal; ba
   assert.match(sessions, /sessionSelectionSource\.current = "history";\s*selectSession\(requestedId\);/);
 });
 
+test("an ordinary composer on a rectification session is disabled until the surface opens", () => {
+  // 原值：inputDisabled / submitBlocked 只看 rectificationSurfaceOpen
+  // 新值：另加 activeRectificationSession；placeholder 为「正在打开生时校正…」
+  // 原因：BUG-924 校正面未开时普通输入框仍可用，问题被发到 /api/consult
+  assert.match(page, /inputDisabled=\{[^}]*activeRectificationSession/);
+  assert.match(page, /ordinaryComposerPlaceholder\(/);
+  assert.match(page, /RectificationComposerReopen/);
+  assert.match(page, /reopenRectificationSession/);
+  assert.doesNotMatch(page, /正在打开生时校正[\s\S]*InlineSpinner/);
+});
+
 test("entry feedback is static: card and sidebar row say 正在打开, and nothing spins after the reveal", () => {
   assert.match(page, /const rectificationCardLabel = rectificationLoading\s*\? RECTIFICATION_OPENING_LABEL/);
   assert.match(starter, /data-opening=\{rectificationLoading \? "true" : undefined\}/);