diff --git a/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.i18n.yaml b/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.i18n.yaml
index 10c60b3355..25e8aa06b6 100644
--- a/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.i18n.yaml
+++ b/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write
-2026-07-21-tui-auto-pane-title.md: 5efa86ae983d276964babad120f3e4131bc20b0d
-2026-07-21-tui-auto-pane-title.zh.md: 3bd1dad8af1bfaf14669e9f0d3df13a4d3c12159
+2026-07-21-tui-auto-pane-title.md: 354602cac465b20157af563ccc32acf82cc54e73
+2026-07-21-tui-auto-pane-title.zh.md: 97178d723b92b243f3bb1b58aa86b681eb9e8573
diff --git a/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.md b/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.md
index 5efa86ae98..354602cac4 100644
--- a/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.md
+++ b/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.md
@@ -4,6 +4,8 @@ Status: implemented
 
 English | [中文](2026-07-21-tui-auto-pane-title.zh.md)
 
+> **Superseded** for the default and the resume behavior by the [auto-title default-on Agent Note](2026-07-21-tui-auto-title-default-on.md): `autoTitle` now defaults on, and a resumed session re-derives its title from the stored first message instead of keeping the static one. The OSC 0 path, the one-shot latch, the model-summary shape, the fire-and-forget call, and every failure fallback below stand.
+
 ## Problem
 
 The TUI's terminal title is a single static string (`title`, default `DeepSeek Harness`) shared by every session. A user who runs one agent per tmux pane or terminal tab sees the same label on all of them, so panes are indistinguishable at a glance and the tab bar carries no signal about what each session is doing.
diff --git a/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.zh.md b/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.zh.md
index 3bd1dad8af..97178d723b 100644
--- a/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.zh.md
+++ b/.agents/notes/implemented/feature/2026-07-21-tui-auto-pane-title.zh.md
@@ -4,6 +4,8 @@ Status: implemented
 
 [English](2026-07-21-tui-auto-pane-title.md) | 中文
 
+> **已被取代**（就默认值与恢复行为而言），见[自动标题默认开启 Agent Note](2026-07-21-tui-auto-title-default-on.md)：`autoTitle` 现默认开启，恢复会话会从已存储的首条消息重新推导标题，而非保留静态标题。下文的 OSC 0 路径、一次性门闩、模型概括形态、发出后不等待其返回的调用，以及每一条失败兜底，均仍然成立。
+
 ## Problem
 
 TUI 的终端标题是一个所有会话共用的静态字符串（`title`，默认 `DeepSeek Harness`）。在 tmux 每个窗格或每个终端标签页各跑一个 agent（智能体）的用户看来，它们的标签全都一样，因此窗格一眼看去无从区分，标签栏也不携带任何关于各会话正在做什么的信号。
diff --git a/.agents/notes/implemented/feature/2026-07-21-tui-auto-title-default-on.i18n.yaml b/.agents/notes/implemented/feature/2026-07-21-tui-auto-title-default-on.i18n.yaml
new file mode 100644
index 0000000000..2137e9d594
--- /dev/null
+++ b/.agents/notes/implemented/feature/2026-07-21-tui-auto-title-default-on.i18n.yaml
@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write
+2026-07-21-tui-auto-title-default-on.md: 1121cf39c79b01dc5e45ff31fccbe82ccee6d101
+2026-07-21-tui-auto-title-default-on.zh.md: 5569c9d71b7481bcf74e39320a52f1f47e7161ed
diff --git a/.agents/notes/implemented/feature/2026-07-21-tui-auto-title-default-on.md b/.agents/notes/implemented/feature/2026-07-21-tui-auto-title-default-on.md
new file mode 100644
index 0000000000..1121cf39c7
--- /dev/null
+++ b/.agents/notes/implemented/feature/2026-07-21-tui-auto-title-default-on.md
@@ -0,0 +1,30 @@
+# Agent Note: Auto-title on by default, re-derived on resume
+
+Status: implemented
+
+English | [中文](2026-07-21-tui-auto-title-default-on.zh.md)
+
+## Problem
+
+The [auto-title Agent Note](2026-07-21-tui-auto-pane-title.md) shipped `autoTitle` off by default and, on a resumed session, kept the static title because the first `user/message` was already logged. In use both choices defeated the feature's purpose. A per-session descriptive pane title is what makes one tmux pane or terminal tab distinguishable from the next; leaving it off by default means the product ships an inert feature that almost no user turns on, and skipping re-derivation on resume means a resumed session — exactly the long-lived session most worth labelling — falls back to the shared static string. The user asked for a descriptive per-session name to be the normal experience.
+
+## Decision
+
+- `autoTitle` defaults **on** (`z.boolean().default(true)`, mirrored by `resolveTuiConfig`'s `?? true`). A deployment with an `llm` service and an agent provider/model gets a model-made pane title on every session without opting in; one without them keeps the static title, so default-on is inert where the call cannot run.
+- A **resumed** session re-derives the title on mount from its already-logged first `user/message`: `createTuiChat` scans `agent.session.events` for the first such event and feeds its text to the same one-shot `generateTitle`. The title is never persisted (the session header carries no title field), so it is always derived, never restored.
+- The one-shot latch is now simply `titleSettled = !resolved.autoTitle`. The prior pre-settle-on-resume clause is gone: on resume `generateTitle` runs once from the stored first message and then latches, so a message that arrives *after* the resume does not re-title. A fresh session has no stored `user/message` at mount, so the resume scan is a no-op and the live `session/event` listener titles the first message instead.
+- Everything else from the [auto-title Agent Note](2026-07-21-tui-auto-pane-title.md) stands unchanged: the OSC 0 `runtime.terminal.setTitle` path, the model-summary shape (two-to-five lowercase words, first non-empty line, 40-char cap), the fire-and-forget `ctx.llm.stream` call that never touches the session or transcript, the shutdown `AbortController`, and every failure fallback (empty reply, missing `llm`, missing provider/model, whitespace-only prompt).
+
+## Alternatives considered
+
+**Keep the feature off by default.** Rejected: this is a direct reversal of the [auto-title Agent Note](2026-07-21-tui-auto-pane-title.md)'s "default off" decision at the user's request. Off-by-default ships an inert feature; the descriptive name is only useful if it is the normal experience. The keyless-replay concern that motivated off-by-default is addressed by pinning `autoTitle: false` in the replay-backed snapshot scenarios rather than by suppressing it for every deployment.
+
+**Persist the derived title in the session header.** Rejected: the header has no title field and adding one would make a terminal label into session metadata — the boundary the [auto-title Agent Note](2026-07-21-tui-auto-pane-title.md) already drew against the log-backed session-title work. Re-deriving from the stored first message costs one tool-less call on resume and keeps the label a pure function of the conversation.
+
+**Re-derive on resume from the latest message instead of the first.** Rejected: the title summarises what the session is *about*, which its opening request captures; a mid-conversation message would make the pane label drift as the work moves on.
+
+## Consequences
+
+- A fresh session with a working `llm` now spends one extra tool-less model call by default (previously only when opted in); a resumed session spends one on mount. Deployments without an `llm` or provider/model are unaffected.
+- The replay-backed `examples/tui-agent/tests/tui.snapshot.ts` must opt **out**: it pins `autoTitle: false`, because a default-on title request is not among the recorded turns and `installLlmReplay` fails loud on an unrecorded request. The unit `packages/ui/tui/tests/tui.snapshot.ts` needs no opt-out — it mounts no `llm` service, so `generateTitle` short-circuits and the default flip is inert there. The interactive `examples/tui-agent/cordis.yml` and the scripted PTY fixture already set `autoTitle: true`, so the keyless smoke's OSC 0 assertion is unchanged.
+- `packages/ui/tui/tests/tui.spec.ts` pins the new defaults: the config-default test expects `autoTitle: true`; the disabled-path test now sets `autoTitle: false` explicitly; and the former "resumed session never fires" test is rewritten to assert re-derivation from the stored first message and that a later live message does not re-title. `docs/config-catalog.md` regenerates to "On by default".
diff --git a/.agents/notes/implemented/feature/2026-07-21-tui-auto-title-default-on.zh.md b/.agents/notes/implemented/feature/2026-07-21-tui-auto-title-default-on.zh.md
new file mode 100644
index 0000000000..5569c9d71b
--- /dev/null
+++ b/.agents/notes/implemented/feature/2026-07-21-tui-auto-title-default-on.zh.md
@@ -0,0 +1,30 @@
+# Agent Note: 自动标题默认开启，恢复时重新推导
+
+Status: implemented
+
+[English](2026-07-21-tui-auto-title-default-on.md) | 中文
+
+## Problem
+
+[自动标题 Agent Note](2026-07-21-tui-auto-pane-title.md) 交付时 `autoTitle` 默认关闭，并且在恢复会话中因首条 `user/message` 已入日志而保留静态标题。实际使用中这两个选择都违背了该功能的初衷。让一个 tmux 窗格或终端标签页区别于下一个的，正是每会话各异的描述性窗格标题；默认关闭意味着产品交付了一个几乎无人开启的惰性功能，而恢复时不重新推导，则意味着恢复会话——恰恰是最值得标记的长命会话——退回到共用的静态字符串。用户要求把每会话的描述性名称做成常态体验。
+
+## Decision
+
+- `autoTitle` 默认**开启**（`z.boolean().default(true)`，`resolveTuiConfig` 以 `?? true` 与之对齐）。带有 `llm` 服务与 agent 提供方/模型的部署无需选择性开启即可在每个会话获得模型制作的窗格标题；不具备它们的部署保留静态标题，因此在调用无法运行处，默认开启是惰性的。
+- **恢复**会话在挂载时从其已入日志的首条 `user/message` 重新推导标题：`createTuiChat` 在 `agent.session.events` 中扫描首个此类事件，并把其文本喂给同一个一次性的 `generateTitle`。标题从不持久化（会话头不携带标题字段），因此它始终是推导得来，而非恢复而来。
+- 一次性门闩现在只是 `titleSettled = !resolved.autoTitle`。此前"恢复即预先结算"的分句已删除：恢复时 `generateTitle` 从已存储的首条消息运行一次随后上闩，因此恢复*之后*到达的消息不会再改标题。全新会话在挂载时没有已存储的 `user/message`，因此恢复扫描是空操作，改由实时的 `session/event` 监听器为首条消息命名。
+- [自动标题 Agent Note](2026-07-21-tui-auto-pane-title.md) 的其余一切保持不变：OSC 0 的 `runtime.terminal.setTitle` 路径、模型概括形态（两到五个小写单词、首个非空行、40 字符上限）、从不触碰会话或 transcript（文本记录）的发出后不等待其返回的 `ctx.llm.stream` 调用、关闭时的 `AbortController`，以及每一条失败兜底（空回复、缺 `llm`、缺提供方/模型、仅含空白的提示词）。
+
+## Alternatives considered
+
+**让该功能保持默认关闭。** 否决：这是应用户要求，对[自动标题 Agent Note](2026-07-21-tui-auto-pane-title.md)"默认关闭"决策的直接反转。默认关闭交付的是惰性功能；只有当描述性名称成为常态体验时它才有用。当初促成默认关闭的无密钥回放顾虑，改由在以回放支撑的快照场景中固定 `autoTitle: false` 来处理，而非为每个部署都压制该功能。
+
+**把推导出的标题持久化进会话头。** 否决：会话头没有标题字段，加一个会把终端标签变成会话元数据——正是[自动标题 Agent Note](2026-07-21-tui-auto-pane-title.md)已经对日志支撑的会话标题工作划出的边界。从已存储的首条消息重新推导，代价是恢复时一次无工具调用，并让标签保持为对话的纯函数。
+
+**恢复时从最新消息而非首条消息重新推导。** 否决：标题概括的是会话*关于什么*，而这由其开场请求捕获；一条对话中途的消息会让窗格标签随工作推进而漂移。
+
+## Consequences
+
+- 带可用 `llm` 的全新会话现在默认多花一次无工具的模型调用（此前只在选择性开启时才有）；恢复会话在挂载时花掉一次。不具备 `llm` 或提供方/模型的部署不受影响。
+- 以回放支撑的 `examples/tui-agent/tests/tui.snapshot.ts` 必须选择**关闭**：它固定 `autoTitle: false`，因为默认开启的标题请求不在录制轮次之列，而 `installLlmReplay` 对未录制的请求会显式报错。单元 `packages/ui/tui/tests/tui.snapshot.ts` 无需选择关闭——它不挂载 `llm` 服务，因此 `generateTitle` 提前短路，默认值的翻转在那里是惰性的。交互式的 `examples/tui-agent/cordis.yml` 与脚本化 PTY fixture（测试前置数据）已设 `autoTitle: true`，因此无密钥冒烟测试的 OSC 0 断言保持不变。
+- `packages/ui/tui/tests/tui.spec.ts` 固定新的默认值：config 默认测试期望 `autoTitle: true`；关闭路径测试现在显式设 `autoTitle: false`；此前的"恢复会话从不触发"测试改写为断言从已存储首条消息重新推导，并断言之后的实时消息不会再改标题。`docs/config-catalog.md` 重新生成为"On by default"。
diff --git a/examples/tui-agent/tests/tui.snapshot.ts b/examples/tui-agent/tests/tui.snapshot.ts
index 79fd8500db..e2cfffd6d2 100644
--- a/examples/tui-agent/tests/tui.snapshot.ts
+++ b/examples/tui-agent/tests/tui.snapshot.ts
@@ -259,6 +259,9 @@ async function runScenario(scenario: Scenario): Promise<ScenarioResult> {
       color: true,
       showReasoning: true,
       title: 'DSH TUI snapshot',
+      // Off so replay stays deterministic: an auto-title request is not among the
+      // recorded turns. Auto-title's PTY coverage lives in the keyless smoke.
+      autoTitle: false,
       welcome: `Recorded replay: ${scenario.name}`,
       maxToolOutputLines: 8,
     }, {