diff --git a/src/i18n/en.ts b/src/i18n/en.ts
index c955ad042..68c180bd9 100644
--- a/src/i18n/en.ts
+++ b/src/i18n/en.ts
@@ -565,7 +565,7 @@ export const messages: Record<string, string> = {
   'ai.routing.intro': 'You are connected to a Lark (Feishu) topic group. The user is reading on Lark and CANNOT see your terminal output.',
   'ai.routing.must_use_botmux': 'To make the user see something, you MUST send it via the `botmux send` command. Terminal output does NOT reach the chat.',
   'ai.routing.usage_heading': 'How to use it:',
-  'ai.routing.usage_send_when': '- Use `botmux send` for: key conclusions, plans (wait for user approval before acting), final results, progress updates.',
+  'ai.routing.usage_send_when': '- Use `botmux send` for: key conclusions, plans (wait for user approval before acting), final results, progress updates. If no reply is needed, do not explain the silence and do not call `botmux send`; the final assistant message must be exactly `BOTMUX_NO_REPLY`.',
   'ai.routing.usage_send_text': '- Plain text is fine: `botmux send "your message"`. Formatting is auto-handled.',
   'ai.routing.usage_heredoc': '- Multi-line body text MUST use a quoted heredoc / stdin (or a UTF-8 `--content-file`). Never write `botmux send "line1\\nline2"` or pass `JSON.stringify` / JSON-escaped text as a positional argument; shell / botmux do not turn literal `\\n` back into newlines.',
   'ai.routing.heredoc_example': "  Correct multi-line example:\n```bash\nbotmux send <<'EOF'\nline 1\nline 2\nEOF\n```",
@@ -596,7 +596,7 @@ export const messages: Record<string, string> = {
   'ai.shell.multiline_heredoc': 'Multi-line body text MUST use a quoted heredoc / stdin (or a UTF-8 `--content-file`). Never write `botmux send "line1\\nline2"` or pass `JSON.stringify` / JSON-escaped text as a positional argument; shell / botmux do not turn literal `\\n` back into newlines.',
   'ai.shell.heredoc_example': "Correct multi-line example:\n```bash\nbotmux send <<'EOF'\nline 1\nline 2\nEOF\n```",
   'ai.shell.helpers': 'Helpers: `botmux history` (read this session\'s history — thread/topic sessions are topic-scoped; regular-group chat-scope sessions are group-wide), `botmux quoted <message_id>` (fetch a quoted message — only use it when the prompt header shows `[user quoted message ...]`), `botmux bots list` (list other bots in the group).',
-  'ai.shell.when_to_send': 'When to send: key conclusions, plans (wait for user approval before acting), final results, progress updates. A bare `print`/`echo` does NOT count as a reply.',
+  'ai.shell.when_to_send': 'When to send: key conclusions, plans (wait for user approval before acting), final results, progress updates. A bare `print`/`echo` does NOT count as a reply. If no reply is needed, do not explain the silence and do not call `botmux send`; the final assistant message must be exactly `BOTMUX_NO_REPLY`.',
   'ai.shell.mention_gate': '@ decision (mandatory): every `botmux send` MUST explicitly pick one or it errors — `--mention <open_id:name>` (name a person/bot; REQUIRED to communicate or collaborate with another bot) / `--mention-back` (@ the sender of the message you are replying to) / `--no-mention` (none). Choose by VALUE: substantive conclusion the other party should read/confirm/decide → --mention-back; pure record / low-priority / short ack → --no-mention; a contentless "got it" is better not sent. Do not default to --no-mention, and do not @ people for nothing.',
 
   // ─── AI prompt blocks (session-manager) ──────────────────────────────────
@@ -605,7 +605,7 @@ export const messages: Record<string, string> = {
   'ai.available_bots.hint': 'To communicate or collaborate with a bot listed here you MUST --mention its open_id (botmux send --mention ou_xxx ...). Without --mention the other bot receives nothing.',
   'ai.available_bots.hint_collapsed': 'To communicate or collaborate with another bot, first run `botmux bots list` to get its open_id, then --mention it. Without --mention the other bot receives nothing.',
   'ai.available_bots.collapsed_line': 'There are {count} collaborator bots in this chat: {names}.',
-  'ai.followup.reminder': 'Replies must go via `botmux send` — terminal output does not reach the user.',
+  'ai.followup.reminder': 'When a reply is needed, use `botmux send`; when none is needed, do not explain the silence and make the final exactly BOTMUX_NO_REPLY.',
   'ai.cursor.sender_note': 'The sender tag is metadata identifying the current speaker — never copy its open_id or name (e.g. ou_xxx:Alice) into your botmux send body or opening line; to @ the triggerer use botmux send --mention-back.',
   'ai.bridge.attachments_label': '[Attachments]',
   'ai.bridge.mentions_label': '[@Mentions]',
diff --git a/src/i18n/zh.ts b/src/i18n/zh.ts
index cc51e5e8b..ea2f5e6aa 100644
--- a/src/i18n/zh.ts
+++ b/src/i18n/zh.ts
@@ -568,7 +568,7 @@ export const messages: Record<string, string> = {
   'ai.routing.intro': '你连接到了飞书（Lark）话题群。用户在飞书上阅读，看不到你的终端输出。',
   'ai.routing.must_use_botmux': '想让用户看到的内容必须通过 `botmux send` 命令发送，终端输出不会到达聊天。',
   'ai.routing.usage_heading': '使用指南：',
-  'ai.routing.usage_send_when': '- 用 `botmux send` 发送：关键结论、方案（等用户确认再执行）、最终结果、进度更新。',
+  'ai.routing.usage_send_when': '- 用 `botmux send` 发送：关键结论、方案（等用户确认再执行）、最终结果、进度更新。若无需回复，不要解释沉默，也不要调用 `botmux send`；最终 assistant message 必须只输出 `BOTMUX_NO_REPLY`。',
   'ai.routing.usage_send_text': '- 发送纯文本即可：`botmux send "消息"`。格式自动处理。',
   'ai.routing.usage_heredoc': '- 多行正文必须走 quoted heredoc / stdin（或 UTF-8 `--content-file`）；禁止写成 `botmux send "第一行\\n第二行"`，也不要先 `JSON.stringify` / JSON 转义再传位置参数，shell / botmux 不会把字面量 `\\n` 还原成换行。',
   'ai.routing.heredoc_example': "  正确多行示例：\n```bash\nbotmux send <<'EOF'\n第一行\n第二行\nEOF\n```",
@@ -599,7 +599,7 @@ export const messages: Record<string, string> = {
   'ai.shell.multiline_heredoc': '多行正文必须走 quoted heredoc / stdin（或 UTF-8 `--content-file`）；禁止写成 `botmux send "第一行\\n第二行"`，也不要先 `JSON.stringify` / JSON 转义再传位置参数，shell / botmux 不会把字面量 `\\n` 还原成换行。',
   'ai.shell.heredoc_example': "正确多行示例：\n```bash\nbotmux send <<'EOF'\n第一行\n第二行\nEOF\n```",
   'ai.shell.helpers': '辅助命令：`botmux history`（读此会话历史；thread/话题会话拉话题内，普通群 chat-scope 会话拉整群）、`botmux quoted <message_id>`（按需读取被引用的消息，仅在 prompt 头部出现 `[用户引用了消息 ...]` 提示时使用）、`botmux bots list`（查群内其他机器人）。',
-  'ai.shell.when_to_send': '发送时机：关键结论、方案（等用户确认再动手）、最终结果、进度更新。只 print/echo 不算回复。',
+  'ai.shell.when_to_send': '发送时机：关键结论、方案（等用户确认再动手）、最终结果、进度更新。只 print/echo 不算回复。若无需回复，不要解释沉默，也不要调用 `botmux send`；最终 assistant message 必须只输出 `BOTMUX_NO_REPLY`。',
   'ai.shell.mention_gate': '@ 决策（硬性）：每条 `botmux send` 必须显式三选一否则报错——`--mention <open_id:名字>`（点名某人/bot，跟别的 bot 沟通/协作必须用它）/ `--mention-back`（@回触发你的那条消息的发送者）/ `--no-mention`（不@）。按内容价值选：有实质结论要对方看/确认/决策→--mention-back；纯记录/低优先级/简短确认→--no-mention；没信息量的"收到"不如不发。别把 --no-mention 当默认，也别无意义 @ 打扰。',
 
   // ─── AI prompt blocks (session-manager) ──────────────────────────────────
@@ -608,7 +608,7 @@ export const messages: Record<string, string> = {
   'ai.available_bots.hint': '要跟这里的某个 bot 沟通或协作必须 --mention 它的 open_id（botmux send --mention ou_xxx ...），不 --mention 对方 bot 完全收不到消息',
   'ai.available_bots.hint_collapsed': '要跟别的 bot 沟通或协作先 `botmux bots list` 查 open_id 再 --mention，不 --mention 对方收不到',
   'ai.available_bots.collapsed_line': '群里有 {count} 个可协作 bot：{names}。',
-  'ai.followup.reminder': '回复必须 botmux send，终端输出用户看不到',
+  'ai.followup.reminder': '需要回复时必须 botmux send；无需回复时不要解释沉默，final 只输出 BOTMUX_NO_REPLY',
   'ai.cursor.sender_note': 'sender 标签只是元信息（标识当前发言人），不要把其中的 open_id 或名字（例如 ou_xxx:高鹏）抄进 botmux send 的正文或开头；要 @ 回触发者请用 botmux send --mention-back。',
   'ai.bridge.attachments_label': '[附件]',
   'ai.bridge.mentions_label': '[@提及]',
diff --git a/src/services/bridge-fallback-gate.ts b/src/services/bridge-fallback-gate.ts
index 4747660e7..056a88bec 100644
--- a/src/services/bridge-fallback-gate.ts
+++ b/src/services/bridge-fallback-gate.ts
@@ -8,6 +8,10 @@
  * disk and threads them through here.
  *
  * Rules:
+ *   - Non-adopt + exact no-reply sentinel: suppress. Botmux-aware models use
+ *     this explicit protocol when a turn genuinely needs no chat response.
+ *     Exact matching is intentional: prose such as "I should stay silent"
+ *     is still a normal final answer and must not be guessed away.
  *   - Adopt mode never suppresses: in /adopt the model in the adopted
  *     session is unaware of botmux, so transcript drain is the ONLY
  *     channel from model to Lark. There's no `botmux send` to compete
@@ -35,6 +39,12 @@ import { normaliseForFingerprint } from './bridge-turn-queue.js';
 const MATERIAL_FINAL_LENGTH_RATIO = 2;
 const MATERIAL_FINAL_MIN_EXTRA_CHARS = 120;
 
+export const BRIDGE_NO_REPLY_SENTINEL = 'BOTMUX_NO_REPLY';
+
+export function isBridgeNoReplyFinal(finalText: string | undefined): boolean {
+  return finalText?.trim() === BRIDGE_NO_REPLY_SENTINEL;
+}
+
 export interface BridgeSendMarker {
   sentAtMs: number;
   messageId?: string;
@@ -98,6 +108,7 @@ export function shouldSuppressBridgeEmit(
   adoptMode: boolean,
 ): boolean {
   if (adoptMode) return false;
+  if (isBridgeNoReplyFinal(turn.finalText)) return true;
   if (turn.isLocal) return true;
   if (turn.markTimeMs === undefined) return false;
   const lower = turn.markTimeMs;
diff --git a/test/bridge-fallback-gate.test.ts b/test/bridge-fallback-gate.test.ts
index 2cf2ee887..569bd5a83 100644
--- a/test/bridge-fallback-gate.test.ts
+++ b/test/bridge-fallback-gate.test.ts
@@ -1,5 +1,6 @@
 import { describe, it, expect } from 'vitest';
 import {
+  BRIDGE_NO_REPLY_SENTINEL,
   shouldEmitEmptyCompletedBridgeFallback,
   shouldSuppressBridgeEmit,
   type BridgeSendMarker,
@@ -18,6 +19,33 @@ const markerForContent = (sentAtMs: number, content: string): BridgeSendMarker =
 };
 
 describe('shouldSuppressBridgeEmit', () => {
+  it('non-adopt: exact no-reply sentinel suppresses without a send marker', () => {
+    expect(shouldSuppressBridgeEmit(
+      { ...turn(100), finalText: `  ${BRIDGE_NO_REPLY_SENTINEL}\n` },
+      undefined,
+      [],
+      false,
+    )).toBe(true);
+  });
+
+  it('non-adopt: prose about staying silent is not guessed away', () => {
+    expect(shouldSuppressBridgeEmit(
+      { ...turn(100), finalText: `I will stay silent instead of replying. ${BRIDGE_NO_REPLY_SENTINEL}` },
+      undefined,
+      [],
+      false,
+    )).toBe(false);
+  });
+
+  it('adopt mode does not interpret the no-reply sentinel', () => {
+    expect(shouldSuppressBridgeEmit(
+      { ...turn(100), finalText: BRIDGE_NO_REPLY_SENTINEL },
+      undefined,
+      [],
+      true,
+    )).toBe(false);
+  });
+
   it('adopt mode never suppresses, even with markers in window', () => {
     const markers: BridgeSendMarker[] = [{ sentAtMs: 150 }];
     expect(shouldSuppressBridgeEmit(turn(100), 200, markers, true)).toBe(false);
diff --git a/test/cli-adapters.test.ts b/test/cli-adapters.test.ts
index 00a2ef660..41bacde73 100644
--- a/test/cli-adapters.test.ts
+++ b/test/cli-adapters.test.ts
@@ -1421,6 +1421,10 @@ describe('systemHints', () => {
     expect(hints.length).toBeGreaterThan(0);
     expect(hints.some(h => h.includes('botmux send'))).toBe(true);
   });
+
+  it('traex systemHints declare the exact no-reply protocol', () => {
+    expect(createTraexAdapter('/bin/traex').systemHints.join('\n')).toContain('BOTMUX_NO_REPLY');
+  });
 });
 
 // ---------------------------------------------------------------------------
diff --git a/test/prompt-builder.test.ts b/test/prompt-builder.test.ts
index 2a8c7848a..b646a1efc 100644
--- a/test/prompt-builder.test.ts
+++ b/test/prompt-builder.test.ts
@@ -321,7 +321,7 @@ describe('buildFollowUpContent', () => {
     expect(content.indexOf('<mentions>')).toBeGreaterThan(content.indexOf('</user_message>'));
     // Complex send guidance is discoverable once in the opening catalog; keep
     // every follow-up reminder intentionally tiny.
-    expect(content).toContain('<botmux_reminder>回复必须 botmux send，终端输出用户看不到</botmux_reminder>');
+    expect(content).toContain('<botmux_reminder>需要回复时必须 botmux send；无需回复时不要解释沉默，final 只输出 BOTMUX_NO_REPLY</botmux_reminder>');
     expect(content).not.toContain('JSON.stringify');
     expect(content).not.toContain('botmux skill show botmux-send');
   });