diff --git a/.agents/notes/implemented/feature/2026-07-26-code-mode-trajectory-waterfall-spans.i18n.yaml b/.agents/notes/implemented/feature/2026-07-26-code-mode-trajectory-waterfall-spans.i18n.yaml
new file mode 100644
index 0000000000..233e1ce72a
--- /dev/null
+++ b/.agents/notes/implemented/feature/2026-07-26-code-mode-trajectory-waterfall-spans.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
+2026-07-26-code-mode-trajectory-waterfall-spans.md: fe4dcc25dbf211cf69e0d33937cf87a7482852e2
+2026-07-26-code-mode-trajectory-waterfall-spans.zh.md: aaae06b1fca1b5587d06aa7704adec421d2b2c27
diff --git a/.agents/notes/implemented/feature/2026-07-26-code-mode-trajectory-waterfall-spans.md b/.agents/notes/implemented/feature/2026-07-26-code-mode-trajectory-waterfall-spans.md
new file mode 100644
index 0000000000..fe4dcc25db
--- /dev/null
+++ b/.agents/notes/implemented/feature/2026-07-26-code-mode-trajectory-waterfall-spans.md
@@ -0,0 +1,31 @@
+# Agent Note: Code Mode sub-calls in the trajectory and waterfall views
+
+Status: implemented
+
+English | [中文](2026-07-26-code-mode-trajectory-waterfall-spans.zh.md)
+
+> Scope: the final PR of the Code Mode UI stack — sub-dispatch rendering in the two non-chat views. Chat nesting is owned by the [sub-call rows note](2026-07-26-code-mode-chat-subcall-rows.md); the timing this consumes is the [live-parallel note](2026-07-26-code-mode-live-parallel-dispatch.md)'s start/settle pair.
+
+## Problem
+
+Trajectory and waterfall still rendered a `run_code` turn as one opaque Tool cell / one node-count bar. The chat view got nested sub-rows in the earlier PRs, but the two analytical views — whose whole purpose is structure and timing — showed none of the sub-call structure and none of the per-sub-call wall time the dispatch pair now records. Waterfall sub-spans were deliberately deferred until that pair existed: a span without real timing would have been a lie.
+
+## Decision
+
+**Trajectory: `subtool` cells interleaved after their parent Tool cell. Waterfall: real-time sub-lanes under the owning turn row.**
+
+- **Trajectory**: the layout fold takes the snapshot's `codeDispatches` index; after each Tool cell whose `callId` has dispatches (assistant-block calls, orphan results, and running calls alike), it interleaves one `subtool` cell per sub-dispatch in start order — indexes stay sequential across the interleave. A settled sub-call's duration is its start/settle pair (`durationSeconds(sub.time, sub.callTime)`); a running one shows the em dash, exactly the native in-flight convention. The new cell kind wears a `Sub` tag (business tint) and a 28px indent so nesting reads at a glance.
+- **Waterfall**: `deriveSubSpans` folds the dispatch index into per-turn lanes with REAL timing — each parent's dispatch window is first start → last settle, and every lane's offset/width is its fraction of that window, so parallel sub-calls (PR3) visibly overlap. Each lane carries a `timing` provenance tag: `measured` (pair observed), `running` (settle pending — extends to the window end at reduced opacity), or `unknown` (settle-only replay window, `callTime: null` — drawn hollow and titled "duration unknown", never a fabricated 0 ms). Lanes draw under the owning turn's bar row, scaled into a fixed lane budget.
+- Both views read `codeDispatches` through the standard snapshot hook — no new wire data, no new stores; replay renders identically to live by construction.
+
+## Alternatives considered
+
+**Fold sub-calls into the turn-span node counts (weight the existing bars).** Rejected: it hides exactly the structure this stack exists to show, and node-count weighting is already flagged as a stand-in (deviation ledger #3).
+
+**A dedicated sub-call panel instead of in-view nesting.** Rejected: the stack's settled UX is nesting under the parent everywhere; a separate panel would diverge from chat and double the selection plumbing.
+
+**Defer waterfall lanes until the P-III duration-lane redesign.** Rejected: the sub-lane timing is real today (the pair), and the fraction-of-window rendering is independent of whatever the turn-level lanes become; deferring would strand the stack's timing payoff.
+
+## Consequences
+
+The waterfall carries the first REAL wall-time rendering in the client (turn bars remain node-count stand-ins — the contrast is deliberate and labeled by hover titles). Trajectory cell indexes now count sub-calls, so `#N` totals grow on Code Mode turns. Specs pin the interleave order and durations, the running em-dash arm, window fractions (offsets/widths), the running-lane extension, the unknown-timing (settle-only) lane, and the rendered lane under the turn row; the built-client Code Mode fixture snapshot additionally pins both tabs' assembled rendering (sub-cells with real +0.8s durations, measured lanes).
diff --git a/.agents/notes/implemented/feature/2026-07-26-code-mode-trajectory-waterfall-spans.zh.md b/.agents/notes/implemented/feature/2026-07-26-code-mode-trajectory-waterfall-spans.zh.md
new file mode 100644
index 0000000000..aaae06b1fc
--- /dev/null
+++ b/.agents/notes/implemented/feature/2026-07-26-code-mode-trajectory-waterfall-spans.zh.md
@@ -0,0 +1,31 @@
+# Agent Note：trajectory 与 waterfall 视图中的 Code Mode 子调用
+
+Status: implemented
+
+[English](2026-07-26-code-mode-trajectory-waterfall-spans.md) | 中文
+
+> 范围：Code Mode UI 堆叠 PR（Pull Request）链的最后一个 PR，涵盖两个非 chat 视图中的子分发渲染。chat 的嵌套归[子调用行 Agent Note](2026-07-26-code-mode-chat-subcall-rows.md)所有；本篇所消费的计时即[实时并行 Agent Note](2026-07-26-code-mode-live-parallel-dispatch.md)的 start/settle 事件对。
+
+## 问题
+
+trajectory 过去仍把一个 `run_code` 轮次渲染为单个不透明的 Tool 单元格，waterfall 则渲染为一根节点计数条。chat 视图在此前的几个 PR 中已获得嵌套子行，但这两个分析视图（其全部意义恰恰是结构与计时）过去既不显示任何子调用结构，也不显示分发事件对如今已记录的逐子调用墙钟时间。waterfall 的子调用 span 曾被刻意推迟到该事件对存在之后：没有真实计时的 span 就是在撒谎。
+
+## 决策
+
+**trajectory：`subtool` 单元格穿插在其父 Tool 单元格之后。waterfall：所属轮次行之下、带真实计时的子泳道（sub-lane）。**
+
+- **trajectory**：布局 fold 接收快照的 `codeDispatches` 索引；凡某个 Tool 单元格的 `callId` 名下存在分发（assistant 块内的调用、孤儿结果与运行中的调用一视同仁），fold 就在该单元格之后按启动顺序为每个子分发穿插一个 `subtool` 单元格，索引在整个穿插序列中保持连续编号。已结算子调用的耗时来自其 start/settle 事件对（`durationSeconds(sub.time, sub.callTime)`）；运行中的子调用则显示破折号，与原生的进行中约定完全一致。新增的单元格类型带有 `Sub` 标签（business 色调）与 28px 缩进，嵌套关系一眼可辨。
+- **waterfall**：`deriveSubSpans` 把分发索引折叠成带真实计时的逐轮次泳道：每个父调用的分发窗口为首个 start → 最后一个 settle，每条泳道的偏移/宽度即其在该窗口中的占比，因此并行的子调用（PR3）会肉眼可见地重叠。每条泳道带有 `timing` 来源标记：`measured`（观察到了成对事件）、`running`（settle 未到 — 以较低不透明度延伸至窗口末端）或 `unknown`（回放窗口只含 settle、`callTime: null` — 画成空心并以「duration unknown」为悬停标题，绝不伪造 0 ms）。泳道绘制在所属轮次的条形行之下，并缩放进固定的泳道预算。
+- 两个视图都经由标准的快照 hook 读取 `codeDispatches`：没有新的 wire 数据，也没有新的 store；回放的渲染由构造保证与实时完全一致。
+
+## 曾考虑的替代方案
+
+**把子调用折入轮次 span 的节点计数（给既有的条加权）。** 否决：它隐藏的恰恰是本堆叠 PR 链存在就是为了展示的结构，而且节点计数加权本就已被标记为占位（偏差账本 #3）。
+
+**用专用的子调用面板取代视图内嵌套。** 否决：本堆叠 PR 链已敲定的 UX 是处处嵌套在父级之下；独立面板会与 chat 发生偏差，还会让选中接线翻倍。
+
+**把 waterfall 泳道推迟到 P-III 的时长泳道重新设计。** 否决：子泳道的计时如今已是真实的（即那对事件），而按窗口占比的渲染与轮次级泳道将来的形态无关；推迟只会让本堆叠 PR 链的计时收益搁浅。
+
+## 后果
+
+waterfall 承载了 client 中第一处真实的墙钟时间渲染（轮次条仍是节点计数的占位；这一反差是有意为之，并由悬停标题标注）。trajectory 的单元格索引现在会把子调用计入，因此 Code Mode 轮次上的 `#N` 总数会随之增大。spec 锁定穿插顺序与耗时、运行中的破折号分支、窗口占比（偏移/宽度）、运行中泳道的延伸、unknown 计时（仅 settle）泳道，以及轮次行之下实际渲染出的泳道；构建产物级的 Code Mode fixture 快照另行锁定两个标签页的组装后渲染（带真实 +0.8s 耗时的子单元格、measured 泳道）。
diff --git a/.agents/notes/implemented/process/2026-07-26-web-syntax-highlighting-shiki.i18n.yaml b/.agents/notes/implemented/process/2026-07-26-web-syntax-highlighting-shiki.i18n.yaml
new file mode 100644
index 0000000000..9fd37bcedb
--- /dev/null
+++ b/.agents/notes/implemented/process/2026-07-26-web-syntax-highlighting-shiki.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
+2026-07-26-web-syntax-highlighting-shiki.md: b329e35f1d0ce7b3de454758403a09f67056b5af
+2026-07-26-web-syntax-highlighting-shiki.zh.md: 8e9d1f0d0c38ce64bcb5da1262538da762f70b12
diff --git a/.agents/notes/implemented/process/2026-07-26-web-syntax-highlighting-shiki.md b/.agents/notes/implemented/process/2026-07-26-web-syntax-highlighting-shiki.md
new file mode 100644
index 0000000000..b329e35f1d
--- /dev/null
+++ b/.agents/notes/implemented/process/2026-07-26-web-syntax-highlighting-shiki.md
@@ -0,0 +1,32 @@
+# Agent Note: Web client syntax highlighting — synchronous fine-grained shiki
+
+Status: implemented
+
+English | [中文](2026-07-26-web-syntax-highlighting-shiki.zh.md)
+
+> Scope: the web client's one syntax-highlighting system — the dependency ruling, the singleton shape, the token-sheet contract, and the consuming surfaces. Fifth PR of the Code Mode UI stack; the [chat sub-call rows note](../feature/2026-07-26-code-mode-chat-subcall-rows.md) shipped the `run_code` program body this exists to make readable. Styling ground rules are owned by [the web styling ruling](2026-07-19-web-styling-system.md).
+
+## Problem
+
+The client rendered every code surface — markdown fences in assistant prose, the `run_code` program body, the details panel's args — as flat monospace text. The stack's primary payload is model-written TypeScript; unhighlighted programs are measurably harder to scan, and the repo already ships shiki-highlighted code on its VitePress site, so the web app was the one code-rendering surface without it.
+
+## Decision
+
+**Shiki in its synchronous fine-grained form, as one `ui-primitives` singleton, themed exclusively through CSS custom properties.**
+
+- **Dependency**: `shiki/core` + `@shikijs/langs`, composed via `createHighlighterCoreSync` with `createJavaScriptRegexEngine({ forgiving: true })` — no oniguruma WASM, no async init, bundle-friendly. Grammar allowlist: `typescript` (embeds JS), `shellscript`, `json` — the languages the harness actually renders; everything else falls back to a geometry-identical plain block, never an error. Prior art: the VitePress site already renders all documentation code through shiki, and TextMate grammars materially beat regex highlighters on TypeScript — the payload that matters here.
+- **Singleton**: `ui-primitives/src/markdown/highlight.ts` creates one `HighlighterCore` per document and exposes `highlightToHtml(code, lang)` (undefined = render plain). Engine + grammar construction is a ~120-175ms long task, so the module pre-warms the singleton in a deferred task at plugin boot (the lazy path stays as the correctness fallback), keeping the cost off the render path where a stream's finalize swap would jank. The alias table is a `Map`, not an object: fence info strings are assistant-authored, so a label like `constructor` must miss instead of resolving an inherited property and crashing shiki. The shared `CodeBlock` component owns both arms; its shiki arm injects the generated span tree via `dangerouslySetInnerHTML` — sanctioned because shiki emits a static span tree computed from the code text (no user HTML passes through, no scripts/handlers), shiki's own documented consumption path.
+- **Theming**: shiki's `createCssVariablesTheme` routes every token color through `--shiki-*` custom properties; the VALUES live in a new `ui-theme/styles/shiki.css` token sheet (light on `:root`, dark on `body[data-ds-dark-theme]` — the same cascade as every other sheet), imported by the shell's `base.css` chain. Component CSS stays tokens-only; no literal color ever enters JS or component sheets. Background/foreground alias the existing markdown code-block tokens so highlighted and plain blocks agree.
+- **Surfaces**: markdown fences (`MarkdownText`'s `pre` component routes single-string fences through `CodeBlock`), the `run_code` expanded program body (ToolRow's code variant, `lang="typescript"`), and the details panel's Input args (`lang="json"`). Output stays plain deliberately — tool output is arbitrary text, and guessing a grammar would mis-highlight more than it helps.
+
+## Alternatives considered
+
+**`rehype-highlight`/lowlight.** Runner-up: naturally sync and ~⅓ the bundle, but regex-grammar fidelity on TypeScript is visibly worse, and the repo would then run two highlighter systems (site: shiki, app: highlight.js) with two theming vocabularies.
+
+**Full `shiki` bundle or the oniguruma WASM engine.** Rejected: the full bundle ships every grammar/theme; WASM needs async loading the sync client boot deliberately avoids. The fine-grained core with three grammars keeps the cost proportional to actual use.
+
+**Highlight in a worker / async.** Rejected: the payloads are small (programs, fences, args); the synchronous JS engine tokenizes them in microseconds, and async introduces a flash-of-unhighlighted-code plus render-machinery churn for no measured need.
+
+## Consequences
+
+One code surface for every consumer — a future surface imports `CodeBlock` and inherits highlighting, theming, and the plain fallback. The bundle grows by the shiki core + three grammars (paid once in `ui-primitives`). Token colors are the first `--shiki-*` sheet; a theme package registering alias overrides extends them like any other token. jsdom specs pin the token-span structure, alias resolution, both fallback arms, and the fence route; the existing built-bundle snapshot and browser e2e cover the assembled path.
diff --git a/.agents/notes/implemented/process/2026-07-26-web-syntax-highlighting-shiki.zh.md b/.agents/notes/implemented/process/2026-07-26-web-syntax-highlighting-shiki.zh.md
new file mode 100644
index 0000000000..8e9d1f0d0c
--- /dev/null
+++ b/.agents/notes/implemented/process/2026-07-26-web-syntax-highlighting-shiki.zh.md
@@ -0,0 +1,32 @@
+# Agent Note：web client 的语法高亮——同步细粒度的 shiki
+
+Status: implemented
+
+[English](2026-07-26-web-syntax-highlighting-shiki.md) | 中文
+
+> 范围：web client 唯一的一套语法高亮体系——依赖裁决、单例形态、token 表契约与各消费表面。本篇是 Code Mode UI 堆叠 PR（Pull Request）链的第五个 PR；[chat 子调用行 Agent Note](../feature/2026-07-26-code-mode-chat-subcall-rows.md)交付了 `run_code` 程序正文，而本体系存在的意义正是让它可读。样式的基本规则归 [Web 样式体系裁决](2026-07-19-web-styling-system.md)所有。
+
+## 问题
+
+client 过去把每一处代码表面——assistant 正文里的 markdown 围栏代码块、`run_code` 程序正文、details 面板的参数——一律渲染成不带高亮的等宽纯文本。本堆叠 PR 链的主要载荷是模型撰写的 TypeScript；未经高亮的程序扫读起来明显更吃力，而仓库已经在自家 VitePress 站点上交付经 shiki 高亮的代码，于是 web 应用成了唯一不带语法高亮的代码渲染表面。
+
+## 决策
+
+**采用同步细粒度形态的 shiki，作为 `ui-primitives` 里的一个单例，主题化完全经由 CSS 自定义属性完成。**
+
+- **依赖**：`shiki/core` + `@shikijs/langs`，经 `createHighlighterCoreSync` 搭配 `createJavaScriptRegexEngine({ forgiving: true })` 组装——不带 oniguruma WASM、没有异步初始化、对 bundle 友好。语法（grammar）白名单：`typescript`（内嵌 JS）、`shellscript`、`json`——即 harness 实际会渲染的那几种语言；其余一律回退到几何完全一致的纯文本块，绝不报错。先例：VitePress 站点已经通过 shiki 渲染全部文档代码；而在 TypeScript（正是此处要紧的载荷）上，TextMate 语法实质性优于正则高亮器。
+- **单例**：`ui-primitives/src/markdown/highlight.ts` 为每个 document 创建一个 `HighlighterCore`，并公开 `highlightToHtml(code, lang)`（undefined 即渲染为纯文本）。引擎加语法的构建是一次约 120-175ms 的长任务，因此模块在插件启动时用延迟任务预热单例（惰性路径保留为正确性兜底），把这笔开销挪出渲染路径——否则流式 finalize 交换的那一刻会卡顿。别名表用 `Map` 而非对象：fence 信息串由 assistant 撰写，诸如 `constructor` 这样的标签必须落空，而不是解析到继承属性并让 shiki 崩溃。共享的 `CodeBlock` 组件同时拥有两条分支；其 shiki 分支经 `dangerouslySetInnerHTML` 注入生成的 span 树——此用法获准，因为 shiki 输出的是从代码文本计算出的静态 span 树（不流经任何用户 HTML，没有脚本或事件处理器），这正是 shiki 自身文档载明的消费路径。
+- **主题化**：shiki 的 `createCssVariablesTheme` 让每一种 token 颜色都经由 `--shiki-*` 自定义属性路由；取值本身住在新增的 `ui-theme/styles/shiki.css` token 表里（亮色在 `:root`、暗色在 `body[data-ds-dark-theme]`——层叠方式与其余每张样式表相同），由壳的 `base.css` 导入链引入。组件 CSS 保持只用 token；任何字面颜色都不进入 JS 或组件样式表。背景/前景以别名指向既有的 markdown 代码块 token，使高亮块与纯文本块彼此一致。
+- **表面**：markdown 围栏代码块（`MarkdownText` 的 `pre` 组件把单字符串围栏路由到 `CodeBlock`）、`run_code` 展开后的程序正文（ToolRow 的 code 变体，`lang="typescript"`），以及 details 面板的 Input 参数（`lang="json"`）。输出有意保持纯文本——工具输出是任意文本，硬猜一种语法，带来的误高亮会多于帮助。
+
+## 曾考虑的替代方案
+
+**`rehype-highlight`/lowlight。** 屈居次选：天然同步，bundle 体积约为三分之一，但基于正则的语法在 TypeScript 上的保真度肉眼可见地更差，而且仓库将从此同时运行两套高亮体系（站点用 shiki、应用用 highlight.js）、维护两套主题化词汇。
+
+**完整的 `shiki` bundle，或 oniguruma WASM 引擎。** 否决：完整 bundle 会带上每一种语法和主题；WASM 需要异步加载，而这正是同步的 client 启动刻意规避的。细粒度 core 加三种语法，让成本与实际用量成正比。
+
+**在 worker 中高亮/异步高亮。** 否决：载荷都很小（程序、围栏代码块、参数）；同步 JS 引擎微秒级就能把它们 token 化，而异步会引入一段未高亮代码的闪现，外加渲染机制的扰动，却没有任何实测得出的需要。
+
+## 后果
+
+所有消费方共用同一个代码表面——未来的新表面导入 `CodeBlock` 即继承高亮、主题化与纯文本回退。bundle 的增量是 shiki core 加三种语法（在 `ui-primitives` 中一次性支付）。token 颜色是第一张 `--shiki-*` 表；注册别名覆写的主题包扩展它们的方式与扩展任何其他 token 无异。jsdom spec 锁定 token span 结构、别名解析、两条回退分支与围栏路由；既有的已构建 bundle 快照和浏览器 e2e 覆盖组装后的路径。
diff --git a/apps/web/tests/code-mode-fixture.snapshot.ts b/apps/web/tests/code-mode-fixture.snapshot.ts
index 46549179be..6f4085da44 100644
--- a/apps/web/tests/code-mode-fixture.snapshot.ts
+++ b/apps/web/tests/code-mode-fixture.snapshot.ts
@@ -5,7 +5,8 @@
 // the code-variant parent row titled by the model-authored description, its
 // three always-visible nested sub-rows (bash through the sample registration,
 // read through GenericToolCard, the failing read wearing the error state),
-// the expanded program body, and details-panel resolution of a sub-callId.
+// the expanded program body, details-panel resolution of a sub-callId, and
+// the trajectory/waterfall tabs' sub-call cells and timing lanes.
 import { readFileSync } from 'node:fs'
 import { join } from 'node:path'
 import { act, cleanup, fireEvent, screen, waitFor, within } from '@testing-library/react'
@@ -155,13 +156,20 @@ it('expands the code row into the program body and resolves a sub-row through th
   boot()
   await openFixtureSession()
 
-  // Expand: the leading control reveals the program verbatim.
+  // Expand: the leading control reveals the program (shiki-tokenized: the
+  // text splits into styled spans inside one <pre class="shiki"> tree).
   const codeRoot = document.querySelector('[data-variant="code"]')
   if (codeRoot === null) throw new Error('code-variant row missing')
   const toggle = codeRoot.querySelector('button[aria-expanded]')
   if (toggle === null) throw new Error('code row expand control missing')
   fireEvent.click(toggle)
-  await screen.findByText(/const listing = await tools\.bash/)
+  await waitFor(() => {
+    // Scope to THIS row: the markdown fixture turn also renders shiki pres.
+    const pre = codeRoot.querySelector('pre.shiki')
+    if (pre === null || !(pre.textContent ?? '').includes('const listing = await tools.bash')) {
+      throw new Error('highlighted program body missing under the code row')
+    }
+  })
 
   // Sub-row click → details panel resolves the sub-callId with FULL output.
   const nest = document.querySelector('[data-subcalls]')
@@ -186,3 +194,64 @@ it('expands the code row into the program body and resolves a sub-row through th
     }
   `)
 })
+
+it('trajectory and waterfall surface the run_code sub-calls with real timing', async () => {
+  boot()
+  await openFixtureSession()
+
+  // Switch to the trajectory tab (same slot ring the chat view registers in).
+  fireEvent.click(await screen.findByRole('tab', { name: 'Trajectory' }))
+  await waitFor(() => {
+    expect(document.querySelector('[data-kind="subtool"]')).not.toBeNull()
+  }, { timeout: 10_000 })
+  const subCells = [...document.querySelectorAll('[data-kind="subtool"]')]
+  expect({
+    // Three Sub cells nested under the run_code Tool cell, in dispatch order,
+    // each with a real +N.Ns own-duration off the start/settle pair (the
+    // fixture spaces every event 800ms apart — never the em dash).
+    subCells: subCells.map(cell => visibleText(cell)),
+  }).toMatchInlineSnapshot(`
+    {
+      "subCells": [
+        "#53Subbash · {"command":"ls notes","description":"List notes"}+0.8s",
+        "#54Subread · {"path":"notes/demo.txt"}+0.8s",
+        "#55Subread · {"path":"notes/missing.txt"}+0.8s",
+      ],
+    }
+  `)
+
+  // Waterfall: each sub-call draws a measured lane scaled into the parent
+  // turn's dispatch window.
+  fireEvent.click(screen.getByRole('tab', { name: 'Waterfall' }))
+  await waitFor(() => {
+    expect(document.querySelector('[data-subspan]')).not.toBeNull()
+  }, { timeout: 10_000 })
+  const lanes = [...document.querySelectorAll('[data-subspan]')]
+  expect({
+    lanes: lanes.map(lane => ({
+      label: visibleText(lane.querySelector('[class*="subTag"]') ?? lane),
+      title: lane.querySelector('[data-timing]')?.getAttribute('title'),
+      timing: lane.querySelector('[data-timing]')?.getAttribute('data-timing'),
+    })),
+  }).toMatchInlineSnapshot(`
+    {
+      "lanes": [
+        {
+          "label": "bash",
+          "timing": "measured",
+          "title": "bash · 0.80s",
+        },
+        {
+          "label": "read",
+          "timing": "measured",
+          "title": "read · 0.80s",
+        },
+        {
+          "label": "read",
+          "timing": "measured",
+          "title": "read · 0.80s",
+        },
+      ],
+    }
+  `)
+})
diff --git a/packages/client/ui-conversation/src/client/chat/AssistantMarkdown.tsx b/packages/client/ui-conversation/src/client/chat/AssistantMarkdown.tsx
index 90eb3e3bee..0e91afcc07 100644
--- a/packages/client/ui-conversation/src/client/chat/AssistantMarkdown.tsx
+++ b/packages/client/ui-conversation/src/client/chat/AssistantMarkdown.tsx
@@ -44,7 +44,7 @@ export const AssistantMarkdown = memo(function AssistantMarkdown({ blocks, strea
     <div className={css.root} data-streaming={streaming || undefined}>
       {blocks.map((block, i) => {
         switch (block.kind) {
-          case 'text': return <MarkdownText key={i} text={block.text} />
+          case 'text': return <MarkdownText key={i} text={block.text} streaming={streaming} />
           case 'reasoning': return <ThinkRow key={i} text={block.text} running={streaming && i === last} />
           // Tool-call heads render as tool rows in the chat view's grouping pass.
           case 'tool-call': return null
diff --git a/packages/client/ui-conversation/src/client/chat/ToolRow.module.css b/packages/client/ui-conversation/src/client/chat/ToolRow.module.css
index 204af4573d..16878ae91e 100644
--- a/packages/client/ui-conversation/src/client/chat/ToolRow.module.css
+++ b/packages/client/ui-conversation/src/client/chat/ToolRow.module.css
@@ -87,14 +87,9 @@ button.leading {
   color: var(--dsw-alias-label-tertiary);
 }
 
-/* The code variant's expanded body is the run_code program: monospace on the
-   markdown code-block fill so the program reads as code, not prose. */
-.root[data-variant='code'] .body {
-  font-family: var(--ds-font-family-code);
-  font-size: 13px;
-  line-height: 20px;
-  padding: 6px 8px;
-  margin-left: 22px;
-  border-radius: 6px;
-  background: var(--dsw-alias-markdown-code-block);
+/* The code variant's expanded body is the run_code program, rendered through
+   the shared CodeBlock (shiki-highlighted TypeScript); only indentation is
+   this row's concern. */
+.codeBody {
+  margin: 4px 0 4px 22px;
 }
diff --git a/packages/client/ui-conversation/src/client/chat/ToolRow.tsx b/packages/client/ui-conversation/src/client/chat/ToolRow.tsx
index f1a5ce7440..113241eb5d 100644
--- a/packages/client/ui-conversation/src/client/chat/ToolRow.tsx
+++ b/packages/client/ui-conversation/src/client/chat/ToolRow.tsx
@@ -6,7 +6,7 @@
 
 import { useState, type KeyboardEvent, type MouseEvent, type ReactNode } from 'react'
 import clsx from 'clsx'
-import { StateDot } from '@deepseek-ai/dsh-client-ui-primitives'
+import { CodeBlock, StateDot } from '@deepseek-ai/dsh-client-ui-primitives'
 import { IconChevronDownOutline14 } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { ToolRowState, ToolRowVariant } from '../contract/tool-call-model.ts'
 import css from './ToolRow.module.css'
@@ -96,7 +96,9 @@ export function ToolRow({
           </>
         )}
       </div>
-      {open && <div className={css.body}>{body}</div>}
+      {open && (variant === 'code'
+        ? <CodeBlock code={body} lang="typescript" className={css.codeBody} />
+        : <div className={css.body}>{body}</div>)}
     </div>
   )
 }
diff --git a/packages/client/ui-conversation/src/client/skeleton/DetailsPanel.tsx b/packages/client/ui-conversation/src/client/skeleton/DetailsPanel.tsx
index 6d998aeff9..3d3c84a646 100644
--- a/packages/client/ui-conversation/src/client/skeleton/DetailsPanel.tsx
+++ b/packages/client/ui-conversation/src/client/skeleton/DetailsPanel.tsx
@@ -5,6 +5,7 @@
 // share the store seat exists for) and derives the call material from the
 // session snapshot — no data of its own.
 
+import { CodeBlock } from '@deepseek-ai/dsh-client-ui-primitives'
 import { shallowEqual } from '@deepseek-ai/dsh-client-runtime/client'
 import type { ConversationSnapshot, ToolResultNode } from '@deepseek-ai/dsh-client-runtime/client'
 import type { DetailsSlotProps } from '../contract/slots.ts'
@@ -89,7 +90,7 @@ export function DetailsPanel({ useSession, useStore, closeDetails }: DetailsPane
                   {material.argsRaw !== null && (
                     <section className={css.section}>
                       <div className={css.sectionLabel}>Input</div>
-                      <pre className={css.code}>{pretty(material.argsRaw)}</pre>
+                      <CodeBlock code={pretty(material.argsRaw)} lang="json" />
                     </section>
                   )}
                   <section className={css.section}>
diff --git a/packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx b/packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx
index 4751ea815e..2d61edae1c 100644
--- a/packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx
@@ -152,7 +152,7 @@ describe('run_code sub-calls through the real chat machinery', () => {
     expect(view.getByText('Tool call')).toBeTruthy()
   })
 
-  it('expanding the code row reveals the program body verbatim', async () => {
+  it('expanding the code row reveals the program body verbatim (shiki-tokenized)', async () => {
     const parent = 'call-64'
     const b = await bench(snapshotWith([codeResult(10, parent)], new Map()))
     const view = mountApp(b.slots)
@@ -160,7 +160,12 @@ describe('run_code sub-calls through the real chat machinery', () => {
     const toggle = view.container.querySelector('[data-variant="code"] button[aria-expanded]')
     expect(toggle).not.toBeNull()
     fireEvent.click(toggle!)
-    expect(view.getByText(/const listing = await tools\.bash/)).toBeTruthy()
+    // Shiki splits the program into token spans inside one <pre class="shiki">:
+    // assert the whole text and the highlighted tree rather than one node.
+    const pre = view.container.querySelector('pre.shiki')
+    expect(pre).not.toBeNull()
+    expect(pre!.textContent).toContain('const listing = await tools.bash')
+    expect(pre!.querySelectorAll('span[style]').length).toBeGreaterThan(3)
   })
 
   it('an isError sub-call renders the error state dot exactly like a failed native row', async () => {
diff --git a/packages/client/ui-primitives/package.json b/packages/client/ui-primitives/package.json
index 7f5c3555bd..9ce2bc8676 100644
--- a/packages/client/ui-primitives/package.json
+++ b/packages/client/ui-primitives/package.json
@@ -20,11 +20,13 @@
   },
   "license": "BSD-3-Clause",
   "dependencies": {
+    "@shikijs/langs": "^4.3.1",
     "clsx": "^2.0.0",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-markdown": "^10.1.0",
-    "remark-gfm": "^4.0.1"
+    "remark-gfm": "^4.0.1",
+    "shiki": "^4.3.1"
   },
   "devDependencies": {
     "@deepseek-ai/dsh-invariants": "workspace:^",
diff --git a/packages/client/ui-primitives/src/index.ts b/packages/client/ui-primitives/src/index.ts
index 5eff2e40b2..330a3145bf 100644
--- a/packages/client/ui-primitives/src/index.ts
+++ b/packages/client/ui-primitives/src/index.ts
@@ -17,6 +17,7 @@ export { FishLogo } from './FishLogo.tsx'
 export { BrandWordmark } from './BrandWordmark.tsx'
 export { Tooltip } from './Tooltip.tsx'
 export type { TooltipSide } from './Tooltip.tsx'
+export { CodeBlock } from './markdown/CodeBlock.tsx'
 export { JsonBlock } from './markdown/JsonBlock.tsx'
 export { MarkdownText } from './markdown/MarkdownText.tsx'
 export { MessageText } from './markdown/MessageText.tsx'
diff --git a/packages/client/ui-primitives/src/markdown/CodeBlock.module.css b/packages/client/ui-primitives/src/markdown/CodeBlock.module.css
new file mode 100644
index 0000000000..f9b5f67136
--- /dev/null
+++ b/packages/client/ui-primitives/src/markdown/CodeBlock.module.css
@@ -0,0 +1,27 @@
+/* One code-block geometry for highlighted and plain arms: the shiki <pre>
+   and the fallback <pre> draw identically except for token colors. */
+
+.block :where(pre) {
+  margin: 0;
+  padding: 8px 10px;
+  border-radius: 8px;
+  overflow-x: auto;
+  background: var(--dsw-alias-markdown-code-block);
+  font: var(--dsw-font-markdown-code-block);
+}
+
+/* Shiki inlines its theme background var; route it to the repo token. */
+.block :where(pre.shiki) {
+  background: var(--dsw-alias-markdown-code-block) !important;
+}
+
+.block :where(pre) code {
+  font: inherit;
+  background: none;
+  padding: 0;
+}
+
+.plain {
+  color: var(--dsw-alias-label-primary);
+  white-space: pre;
+}
diff --git a/packages/client/ui-primitives/src/markdown/CodeBlock.tsx b/packages/client/ui-primitives/src/markdown/CodeBlock.tsx
new file mode 100644
index 0000000000..1a6349f1e8
--- /dev/null
+++ b/packages/client/ui-primitives/src/markdown/CodeBlock.tsx
@@ -0,0 +1,37 @@
+// CodeBlock: one code surface for every consumer — markdown fences, the
+// run_code program body, and the details panel's raw args/output — with
+// shiki highlighting for the registered grammars and an identical-geometry
+// plain fallback for everything else. Shiki emits a single <pre class="shiki">
+// tree of nested spans whose colors are --shiki-* custom properties
+// (token sheets own the values); it produces no scripts or event handlers,
+// so injecting its output is safe by construction.
+
+import { useMemo } from 'react'
+import clsx from 'clsx'
+import { highlightToHtml } from './highlight.ts'
+import css from './CodeBlock.module.css'
+
+export interface CodeBlockProps {
+  /** The source text, rendered verbatim (trailing newline trimmed for display). */
+  code: string
+  /** Grammar hint (markdown fence info string or a fixed caller id); unknown = plain. */
+  lang?: string | undefined
+  /** Extra class merged onto the wrapper (callers position; this component draws). */
+  className?: string | undefined
+}
+
+export function CodeBlock({ code, lang, className }: CodeBlockProps) {
+  const trimmed = code.endsWith('\n') ? code.slice(0, -1) : code
+  const html = useMemo(() => highlightToHtml(trimmed, lang), [trimmed, lang])
+  if (html === undefined) {
+    return (
+      <div className={clsx(css.block, className)}>
+        <pre className={css.plain}><code>{trimmed}</code></pre>
+      </div>
+    )
+  }
+  // eslint-disable-next-line react/no-danger -- shiki's output is a static
+  // span tree it generated from `code` (no user HTML passes through), the
+  // sanctioned innerHTML consumption path per shiki's own docs.
+  return <div className={clsx(css.block, className)} dangerouslySetInnerHTML={{ __html: html }} />
+}
diff --git a/packages/client/ui-primitives/src/markdown/MarkdownText.tsx b/packages/client/ui-primitives/src/markdown/MarkdownText.tsx
index 425e3969ab..775978a275 100644
--- a/packages/client/ui-primitives/src/markdown/MarkdownText.tsx
+++ b/packages/client/ui-primitives/src/markdown/MarkdownText.tsx
@@ -1,6 +1,8 @@
+import { isValidElement } from 'react'
 import ReactMarkdown from 'react-markdown'
 import type { Components, UrlTransform } from 'react-markdown'
 import remarkGfm from 'remark-gfm'
+import { CodeBlock } from './CodeBlock.tsx'
 import css from './MarkdownText.module.css'
 
 const remarkPlugins = [remarkGfm]
@@ -22,7 +24,9 @@ function sanitizeUrl(url: string): string {
 
 const safeUrl: UrlTransform = url => sanitizeUrl(url)
 
-const components: Components = {
+/** Build the component table; while `streaming`, fences render the plain arm (see CodeBlock). */
+function buildComponents(streaming: boolean): Components {
+  return {
   a: ({ href = '', children }) => {
     const safeHref = sanitizeUrl(href)
     if (safeHref === '') return <>{children}</>
@@ -42,19 +46,40 @@ const components: Components = {
       <table>{children}</table>
     </div>
   ),
+    // Fenced blocks route through the shared CodeBlock (shiki for registered
+    // grammars, identical-geometry plain fallback for unknown/absent
+    // languages); inline code keeps the default <code> path (the :not(pre)
+    // rule styles it). While the message streams, the fence renders the
+    // plain arm — retokenizing a growing fence on every chunk is quadratic
+    // main-thread work; the finalize swap highlights it once.
+    pre: ({ children }) => {
+      /* v8 ignore next 2 -- the markdown pipeline always hands `pre` its single `code` element; the undefined arm guards a react-markdown representation change. */
+      const child = isValidElement<{ className?: string; children?: unknown }>(children) ? children : undefined
+      const raw = child?.props.children
+      // A fence whose content isn't one plain string (e.g. an empty fence)
+      // keeps the stock <pre> rather than guessing.
+      if (typeof raw !== 'string') return <pre>{children}</pre>
+      const lang = /language-([\w-]+)/.exec(child?.props.className ?? '')?.[1]
+      return <CodeBlock code={raw} lang={streaming ? undefined : lang} />
+    },
+  }
 }
 
+const staticComponents = buildComponents(false)
+const streamingComponents = buildComponents(true)
+
 /**
  * Render untrusted assistant-authored Markdown as semantic React elements.
- * @param props - Markdown source text preserved by the session projection.
+ * @param props - Markdown source text preserved by the session projection;
+ * `streaming` renders fences plain (highlighting lands on the finalize swap).
  * @returns A GFM document with raw HTML, relative links, unsafe protocols, and remote images disabled.
  */
-export function MarkdownText({ text }: { text: string }) {
+export function MarkdownText({ text, streaming = false }: { text: string; streaming?: boolean }) {
   return (
     <div className={css.markdown}>
       <ReactMarkdown
         remarkPlugins={remarkPlugins}
-        components={components}
+        components={streaming ? streamingComponents : staticComponents}
         urlTransform={safeUrl}
       >
         {text}
diff --git a/packages/client/ui-primitives/src/markdown/highlight.ts b/packages/client/ui-primitives/src/markdown/highlight.ts
new file mode 100644
index 0000000000..1fa50f6d2f
--- /dev/null
+++ b/packages/client/ui-primitives/src/markdown/highlight.ts
@@ -0,0 +1,82 @@
+/**
+ * The client's ONE syntax highlighter: a synchronous fine-grained shiki core
+ * (JavaScript regex engine — no oniguruma WASM, bundle-friendly) with an
+ * explicit grammar allowlist and a CSS-variables theme. Colors live in the
+ * theme package's token sheets as `--shiki-*` custom properties (light and
+ * dark blocks), never here — the repo's tokens-only styling rule.
+ *
+ * Grammars are the set the harness actually renders: TypeScript programs
+ * (`run_code` bodies; TS pulls in JS via grammar embedding), shell commands,
+ * and JSON payloads. An unknown or absent language falls back to plain text
+ * (no highlighting, still monospace) — never an error.
+ */
+
+import { createHighlighterCoreSync, createCssVariablesTheme } from 'shiki/core'
+import { createJavaScriptRegexEngine } from 'shiki/engine/javascript'
+import langTs from '@shikijs/langs/typescript'
+import langBash from '@shikijs/langs/shellscript'
+import langJson from '@shikijs/langs/json'
+import type { HighlighterCore } from 'shiki/core'
+
+/**
+ * Language ids (and aliases) the singleton registers; everything else renders
+ * plain. A Map, not an object: fence info strings are assistant-authored, so
+ * a label like `constructor` or `__proto__` must miss instead of resolving an
+ * inherited property and crashing the renderer inside shiki.
+ */
+const LANG_ALIASES = new Map<string, string>([
+  ['typescript', 'typescript'],
+  ['ts', 'typescript'],
+  ['tsx', 'typescript'],
+  ['javascript', 'typescript'],
+  ['js', 'typescript'],
+  ['shellscript', 'shellscript'],
+  ['bash', 'shellscript'],
+  ['sh', 'shellscript'],
+  ['shell', 'shellscript'],
+  ['zsh', 'shellscript'],
+  ['json', 'json'],
+  ['jsonc', 'json'],
+])
+
+/** All token colors resolve through `--shiki-*` custom properties (theme package sheets). */
+const cssVariablesTheme = createCssVariablesTheme({
+  name: 'css-variables',
+  variablePrefix: '--shiki-',
+  fontStyle: true,
+})
+
+let singleton: HighlighterCore | undefined
+
+/** The synchronous highlighter (one instance per document); pre-warmed below, lazy as the fallback. */
+function highlighter(): HighlighterCore {
+  singleton ??= createHighlighterCoreSync({
+    themes: [cssVariablesTheme],
+    langs: [langTs, langBash, langJson],
+    engine: createJavaScriptRegexEngine({ forgiving: true }),
+  })
+  return singleton
+}
+
+// Engine + grammar construction costs a long task (~120-175ms); building it
+// during the first finalized fence's render would jank exactly when a stream
+// completes. Warm the singleton in a deferred task at module load (= plugin
+// boot) instead; the lazy path above stays as the correctness fallback for a
+// fence that renders before the timer fires. `unref` (Node-only) keeps a
+// non-browser import from pinning the event loop.
+const warmupTimer = setTimeout(() => { highlighter() }, 0)
+;(warmupTimer as { unref?: () => void }).unref?.()
+
+/**
+ * Highlight `code` into shiki's HTML (a single `<pre class="shiki">` tree)
+ * when `lang` maps to a registered grammar; `undefined` means the caller
+ * renders its plain fallback.
+ * @param code - the source text.
+ * @param lang - the language hint (a markdown fence info string or a fixed caller id).
+ * @returns the highlighted HTML, or `undefined` for unknown languages.
+ */
+export function highlightToHtml(code: string, lang: string | undefined): string | undefined {
+  const resolved = lang === undefined ? undefined : LANG_ALIASES.get(lang.toLowerCase())
+  if (resolved === undefined) return undefined
+  return highlighter().codeToHtml(code, { lang: resolved, theme: 'css-variables' })
+}
diff --git a/packages/client/ui-primitives/tests/code-block.spec.tsx b/packages/client/ui-primitives/tests/code-block.spec.tsx
new file mode 100644
index 0000000000..a58248afab
--- /dev/null
+++ b/packages/client/ui-primitives/tests/code-block.spec.tsx
@@ -0,0 +1,53 @@
+// @vitest-environment jsdom
+// CodeBlock + the shiki singleton: registered grammars highlight into token
+// spans colored by --shiki-* custom properties; unknown/absent languages take
+// the identical-geometry plain arm; aliases resolve; the trailing newline is
+// display-trimmed. MarkdownText's fence route is pinned in markdown.spec.tsx
+// alongside the rest of the markdown family.
+
+import { describe, expect, it } from 'vitest'
+import { cleanup, render } from '@testing-library/react'
+import { afterEach } from 'vitest'
+import { CodeBlock } from '../src/markdown/CodeBlock.tsx'
+import { highlightToHtml } from '../src/markdown/highlight.ts'
+
+afterEach(cleanup)
+
+describe('highlightToHtml', () => {
+  it('highlights a registered grammar into css-variables token spans', () => {
+    const html = highlightToHtml('const x: number = 1', 'typescript')
+    expect(html).toContain('pre class="shiki css-variables"')
+    expect(html).toContain('var(--shiki-')
+  })
+
+  it.each([['ts'], ['js'], ['bash'], ['sh'], ['jsonc']])('resolves the %s alias', (alias) => {
+    expect(highlightToHtml('x', alias)).toContain('shiki')
+  })
+
+  it('returns undefined for unknown or absent languages', () => {
+    expect(highlightToHtml('x', 'cobol')).toBeUndefined()
+    expect(highlightToHtml('x', undefined)).toBeUndefined()
+  })
+})
+
+describe('CodeBlock', () => {
+  it('renders the highlighted tree for TypeScript', () => {
+    const view = render(<CodeBlock code={'const a = 1\n'} lang="ts" />)
+    const pre = view.container.querySelector('pre.shiki')
+    expect(pre).not.toBeNull()
+    expect(pre!.textContent).toBe('const a = 1')
+    expect(pre!.querySelectorAll('span[style]').length).toBeGreaterThan(1)
+  })
+
+  it('renders the plain arm for an unknown language with the text verbatim', () => {
+    const view = render(<CodeBlock code={'IDENTIFICATION DIVISION.'} lang="cobol" />)
+    expect(view.container.querySelector('pre.shiki')).toBeNull()
+    expect(view.getByText('IDENTIFICATION DIVISION.')).toBeTruthy()
+  })
+
+  it('renders the plain arm when no language is given', () => {
+    const view = render(<CodeBlock code="plain text" />)
+    expect(view.container.querySelector('pre.shiki')).toBeNull()
+    expect(view.getByText('plain text')).toBeTruthy()
+  })
+})
diff --git a/packages/client/ui-primitives/tests/markdown.spec.tsx b/packages/client/ui-primitives/tests/markdown.spec.tsx
index 4e1dc292d4..05c7ce0139 100644
--- a/packages/client/ui-primitives/tests/markdown.spec.tsx
+++ b/packages/client/ui-primitives/tests/markdown.spec.tsx
@@ -57,11 +57,41 @@ describe('MarkdownText', () => {
     expect(container.querySelector('table')?.textContent).toContain('alphabeta')
     expect(container.querySelector('hr')).not.toBeNull()
     expect(container.querySelector('pre code')?.textContent).toContain('const answer = 42')
+    // The ts fence routed through the shared CodeBlock: shiki token spans present.
+    expect(container.querySelector('pre.shiki')).not.toBeNull()
     expect(container.querySelector('br')).not.toBeNull()
     expect(screen.getByRole('link', { name: 'safe' }).getAttribute('target')).toBe('_blank')
     expect(screen.getByRole('link', { name: 'https://deepseek.com' })).toBeTruthy()
   })
 
+  it('a fence labeled with an inherited object key renders plain, never crashing shiki', () => {
+    for (const label of ['constructor', '__proto__', 'toString', 'hasOwnProperty']) {
+      const { container, unmount } = render(<MarkdownText text={'```' + label + '\ncode body\n```'} />)
+      expect(container.querySelector('pre.shiki')).toBeNull()
+      expect(container.querySelector('pre code')?.textContent).toContain('code body')
+      unmount()
+    }
+  })
+
+  it('an empty fence keeps the stock pre; a language-less fence renders the plain CodeBlock arm', () => {
+    const empty = render(<MarkdownText text={'```\n```'} />)
+    expect(empty.container.querySelector('pre')?.outerHTML).toBe('<pre><code></code></pre>')
+
+    const plain = render(<MarkdownText text={'```\nno language here\n```'} />)
+    expect(plain.container.querySelector('pre.shiki')).toBeNull()
+    expect(plain.container.querySelector('pre code')?.textContent).toContain('no language here')
+  })
+
+  it('streaming renders fences plain; the finalize swap highlights them', () => {
+    const fence = '```ts\nconst answer = 42\n```'
+    const live = render(<MarkdownText text={fence} streaming />)
+    expect(live.container.querySelector('pre.shiki')).toBeNull()
+    expect(live.container.querySelector('pre code')?.textContent).toContain('const answer = 42')
+    live.unmount()
+    const done = render(<MarkdownText text={fence} />)
+    expect(done.container.querySelector('pre.shiki')).not.toBeNull()
+  })
+
   it('neutralizes raw HTML, unsafe or relative links, and remote images', () => {
     const markdown = [
       '<script>globalThis.compromised = true</script>',
diff --git a/packages/client/ui-theme/src/styles/shiki.css b/packages/client/ui-theme/src/styles/shiki.css
new file mode 100644
index 0000000000..c7a3c5d272
--- /dev/null
+++ b/packages/client/ui-theme/src/styles/shiki.css
@@ -0,0 +1,31 @@
+/* Syntax-highlight token palette: the values behind shiki's css-variables
+   theme (--shiki-* custom properties emitted by the ui-primitives CodeBlock).
+   Light values on :root, dark overrides on the body attribute — the same
+   cascade as every other token sheet. Background/foreground deliberately
+   alias the markdown code-block tokens so highlighted and plain blocks agree. */
+
+:root {
+  --shiki-foreground: var(--dsw-alias-label-primary);
+  --shiki-background: var(--dsw-alias-markdown-code-block);
+  --shiki-token-constant: #1c7ed6;
+  --shiki-token-string: #2f9e44;
+  --shiki-token-comment: #868e96;
+  --shiki-token-keyword: #d6336c;
+  --shiki-token-parameter: #e8590c;
+  --shiki-token-function: #6741d9;
+  --shiki-token-string-expression: #2b8a3e;
+  --shiki-token-punctuation: #495057;
+  --shiki-token-link: #1971c2;
+}
+
+body[data-ds-dark-theme] {
+  --shiki-token-constant: #4dabf7;
+  --shiki-token-string: #69db7c;
+  --shiki-token-comment: #adb5bd;
+  --shiki-token-keyword: #faa2c1;
+  --shiki-token-parameter: #ffa94d;
+  --shiki-token-function: #b197fc;
+  --shiki-token-string-expression: #8ce99a;
+  --shiki-token-punctuation: #ced4da;
+  --shiki-token-link: #74c0fc;
+}
diff --git a/packages/client/ui-trajectory/src/client/TrajectoryCell.module.css b/packages/client/ui-trajectory/src/client/TrajectoryCell.module.css
index 1120fe2746..c5efc232d1 100644
--- a/packages/client/ui-trajectory/src/client/TrajectoryCell.module.css
+++ b/packages/client/ui-trajectory/src/client/TrajectoryCell.module.css
@@ -61,6 +61,17 @@
   background: var(--dsw-alias-state-warn-tertiary);
 }
 
+/* run_code sub-dispatch cells: the business tint plus an indent so the
+   nesting under the parent Tool cell reads at a glance. */
+.tagSubtool {
+  color: var(--dsw-alias-state-business-primary);
+  background: var(--dsw-alias-state-business-tertiary);
+}
+
+.root[data-kind='subtool'] {
+  padding-left: 28px;
+}
+
 .text {
   flex: 1 1 auto;
   min-width: 0;
diff --git a/packages/client/ui-trajectory/src/client/TrajectoryCell.tsx b/packages/client/ui-trajectory/src/client/TrajectoryCell.tsx
index de99d027d8..94fc6042a4 100644
--- a/packages/client/ui-trajectory/src/client/TrajectoryCell.tsx
+++ b/packages/client/ui-trajectory/src/client/TrajectoryCell.tsx
@@ -4,20 +4,23 @@
 import type { HTMLAttributes } from 'react'
 import css from './TrajectoryCell.module.css'
 
-/** Closed set of trajectory step kinds (call+result fold into Tool; no Think). */
-export type TrajectoryCellKind = 'user' | 'message' | 'tool'
+/** Closed set of trajectory step kinds (call+result fold into Tool; no Think;
+ *  subtool = one run_code sub-dispatch nested under its Tool cell). */
+export type TrajectoryCellKind = 'user' | 'message' | 'tool' | 'subtool'
 
 /** Display label per kind (matches the design tags). */
 const KIND_LABEL: Record<TrajectoryCellKind, string> = {
   user: 'User',
   message: 'Message',
   tool: 'Tool',
+  subtool: 'Sub',
 }
 
 const TAG_CLASS: Record<TrajectoryCellKind, string> = {
   user: css.tagUser!,
   message: css.tagMessage!,
   tool: css.tagTool!,
+  subtool: css.tagSubtool!,
 }
 
 export interface TrajectoryCellProps extends HTMLAttributes<HTMLDivElement> {
diff --git a/packages/client/ui-trajectory/src/client/TrajectoryView.tsx b/packages/client/ui-trajectory/src/client/TrajectoryView.tsx
index 45277eb628..3d417b085e 100644
--- a/packages/client/ui-trajectory/src/client/TrajectoryView.tsx
+++ b/packages/client/ui-trajectory/src/client/TrajectoryView.tsx
@@ -12,9 +12,10 @@ export function TrajectoryView({ useSession }: ConvViewProps) {
   const nodes = useSession((s) => s.nodes)
   const partial = useSession((s) => s.partial)
   const runningCalls = useSession((s) => s.runningCalls)
+  const codeDispatches = useSession((s) => s.codeDispatches)
   const turns = useMemo(
-    () => deriveTrajectoryLayout({ nodes, partial, runningCalls }),
-    [nodes, partial, runningCalls],
+    () => deriveTrajectoryLayout({ nodes, partial, runningCalls, codeDispatches }),
+    [nodes, partial, runningCalls, codeDispatches],
   )
   if (turns.length === 0) {
     return <div className={css.root}><p className={css.empty}>暂无轨迹数据</p></div>
diff --git a/packages/client/ui-trajectory/src/client/WaterfallView.tsx b/packages/client/ui-trajectory/src/client/WaterfallView.tsx
index feeb6a7f16..ad81845fb9 100644
--- a/packages/client/ui-trajectory/src/client/WaterfallView.tsx
+++ b/packages/client/ui-trajectory/src/client/WaterfallView.tsx
@@ -1,16 +1,20 @@
-// WaterfallView: P-I placeholder body for the waterfall tab — span stats
-// header over node-count bars per turn standing in for duration lanes (no
-// timing data yet; deviation ledger #3 defers real rendering to P-III).
+// WaterfallView: span stats header over per-turn node-count lanes (P-I
+// stand-in for duration lanes; deviation ledger #3). run_code turns
+// additionally draw TRUTHFUL sub-call lanes: the dispatch start/settle pair
+// carries per-sub-call wall time, so each sub-span's width is its real
+// duration against the parent turn's dispatch window.
 
 import { useMemo } from 'react'
 import type { ConvViewProps } from '@deepseek-ai/dsh-client-ui-conversation/client'
-import { deriveSpans } from './spans.ts'
+import { deriveSpans, deriveSubSpans } from './spans.ts'
 import { TrajectoryStatsHeader } from './TrajectoryStatsHeader.tsx'
 import css from './views.module.css'
 
 /** Bar width scale: px per node, clamped so tiny windows still show a bar. */
 const PX_PER_NODE = 14
 const MIN_BAR_PX = 8
+/** Sub-span lane width budget (the parent window scales into this). */
+const SUB_LANE_PX = 220
 
 /** Optional density override (test/standalone knob; the register site passes nothing). */
 export interface WaterfallExtraProps {
@@ -21,27 +25,48 @@ export interface WaterfallExtraProps {
 export function WaterfallView({ useSession, pxPerNode }: ConvViewProps & WaterfallExtraProps) {
   const scale = pxPerNode ?? PX_PER_NODE
   const nodes = useSession((s) => s.nodes)
+  const codeDispatches = useSession((s) => s.codeDispatches)
   const spans = useMemo(() => deriveSpans(nodes), [nodes])
+  const subSpans = useMemo(() => deriveSubSpans(nodes, codeDispatches), [nodes, codeDispatches])
   if (spans.length === 0) return <div className={css.root}><p className={css.empty}>暂无瀑布数据</p></div>
   return (
     <>
       <TrajectoryStatsHeader useSession={useSession} />
       <div className={css.root}>
         {spans.map((span, i) => (
-          <div key={span.turn} className={css.row} style={{ paddingLeft: i * 12 }}>
-            <span className={css.turnTag}>turn {span.turn}</span>
-            <span
-              className={css.bar}
-              style={{ width: Math.max(span.nodes * scale, MIN_BAR_PX) }}
-              title={`${span.nodes} nodes`}
-            />
-            {span.calls > 0 && (
+          <div key={span.turn}>
+            <div className={css.row} style={{ paddingLeft: i * 12 }}>
+              <span className={css.turnTag}>turn {span.turn}</span>
               <span
-                className={`${css.bar} ${css.barCalls}`}
-                style={{ width: Math.max(span.calls * scale, MIN_BAR_PX) }}
-                title={`${span.calls} tool calls`}
+                className={css.bar}
+                style={{ width: Math.max(span.nodes * scale, MIN_BAR_PX) }}
+                title={`${span.nodes} nodes`}
               />
-            )}
+              {span.calls > 0 && (
+                <span
+                  className={`${css.bar} ${css.barCalls}`}
+                  style={{ width: Math.max(span.calls * scale, MIN_BAR_PX) }}
+                  title={`${span.calls} tool calls`}
+                />
+              )}
+            </div>
+            {(subSpans.get(span.turn) ?? []).map((lane) => (
+              <div key={lane.callId} className={css.subRow} data-subspan style={{ paddingLeft: i * 12 + 24 }}>
+                <span className={css.subTag}>{lane.name}</span>
+                <span
+                  className={`${css.bar} ${css.barSub}`}
+                  data-timing={lane.timing}
+                  style={{
+                    marginLeft: Math.round(lane.offsetFraction * SUB_LANE_PX),
+                    width: Math.max(Math.round(lane.widthFraction * SUB_LANE_PX), 4),
+                  }}
+                  title={lane.timing === 'measured'
+                    /* durationMs is non-null exactly when timing is measured. */
+                    ? `${lane.name} · ${((lane.durationMs ?? 0) / 1000).toFixed(2)}s`
+                    : lane.timing === 'running' ? `${lane.name} · running` : `${lane.name} · duration unknown`}
+                />
+              </div>
+            ))}
           </div>
         ))}
       </div>
diff --git a/packages/client/ui-trajectory/src/client/layout.ts b/packages/client/ui-trajectory/src/client/layout.ts
index e188498554..37c86f6eb4 100644
--- a/packages/client/ui-trajectory/src/client/layout.ts
+++ b/packages/client/ui-trajectory/src/client/layout.ts
@@ -4,6 +4,7 @@
  */
 import type {
   AssistantMessageNode,
+  CodeSubCall,
   ConversationSnapshot,
   ToolResultNode,
 } from '@deepseek-ai/dsh-client-runtime/client'
@@ -27,6 +28,8 @@ export interface TrajectoryLayoutInput {
   nodes: ConversationSnapshot['nodes']
   partial: ConversationSnapshot['partial']
   runningCalls: ConversationSnapshot['runningCalls']
+  /** run_code sub-dispatches by parent callId (sub-cells nest under the parent Tool cell). */
+  codeDispatches: ConversationSnapshot['codeDispatches']
 }
 
 interface UsageLike {
@@ -49,7 +52,7 @@ interface LaidCell {
  * @returns turns ordered by first appearance.
  */
 export function deriveTrajectoryLayout(input: TrajectoryLayoutInput): readonly TrajectoryTurnModel[] {
-  const { nodes, partial, runningCalls } = input
+  const { nodes, partial, runningCalls, codeDispatches } = input
   const resultByCall = indexResults(nodes)
   const turns = new Map<number, { message: LaidCell[]; steps: Map<number, LaidCell[]> }>()
   let index = 0
@@ -96,7 +99,7 @@ export function deriveTrajectoryLayout(input: TrajectoryLayoutInput): readonly T
       continue
     }
     if (node.kind === 'assistant') {
-      const laidList = expandAssistant(node, index + 1, prevAbsTime, resultByCall)
+      const laidList = withSubCalls(expandAssistant(node, index + 1, prevAbsTime, resultByCall), codeDispatches)
       for (const laid of laidList) {
         if (node.step > 0) pushStep(node.turn, node.step, laid)
         else pushMessage(node.turn, laid)
@@ -128,6 +131,10 @@ export function deriveTrajectoryLayout(input: TrajectoryLayoutInput): readonly T
             timeSeconds: durationSeconds(node.time, node.callTime),
           },
         })
+        for (const laid of expandSubCalls(codeDispatches.get(node.callId), index)) {
+          pushStep(0, 1, laid)
+          index = laid.cell.index
+        }
       }
       prevAbsTime = finiteTime(node.time) ?? prevAbsTime
     }
@@ -161,6 +168,10 @@ export function deriveTrajectoryLayout(input: TrajectoryLayoutInput): readonly T
         timeSeconds: null,
       },
     })
+    for (const laid of expandSubCalls(codeDispatches.get(call.callId), index)) {
+      pushStep(call.turn, call.step > 0 ? call.step : 1, laid)
+      index = laid.cell.index
+    }
   }
 
   // Orphan turn-0 cells (orphaned tools / steering turn 0) fold into Turn 1.
@@ -387,6 +398,53 @@ function collectCallIds(
   return ids
 }
 
+
+
+/** Interleave each tool cell's run_code sub-dispatch cells right after it, reindexing followers. */
+function withSubCalls(laidList: LaidCell[], codeDispatches: ConversationSnapshot['codeDispatches']): LaidCell[] {
+  if (codeDispatches.size === 0) return laidList
+  const out: LaidCell[] = []
+  let index = laidList[0] !== undefined ? laidList[0].cell.index - 1 : 0
+  for (const laid of laidList) {
+    out.push({ ...laid, cell: { ...laid.cell, index: ++index } })
+    if (laid.callId === undefined) continue
+    for (const sub of expandSubCalls(codeDispatches.get(laid.callId), index)) {
+      out.push(sub)
+      index = sub.cell.index
+    }
+  }
+  return out
+}
+
+/** Sub-dispatch cells for one run_code parent, in start order (running = null duration). */
+function expandSubCalls(
+  subs: readonly CodeSubCall[] | undefined,
+  startIndex: number,
+): LaidCell[] {
+  if (subs === undefined || subs.length === 0) return []
+  const out: LaidCell[] = []
+  let index = startIndex
+  for (const sub of subs) {
+    const settled = 'kind' in sub
+    out.push({
+      absTime: settled ? finiteTime(sub.callTime ?? sub.time) : finiteTime(sub.time),
+      toolName: settled ? sub.call?.name ?? sub.callId : sub.name,
+      callId: sub.callId,
+      cell: {
+        index: ++index,
+        kind: 'subtool',
+        text: settled
+          ? (sub.call !== null ? summarizeCall(sub.call.name, sub.call.argsRaw) : summarizeResult(sub))
+          : summarizeCall(sub.name, sub.argsRaw),
+        // PR3's start/settle pair carries per-sub-call wall time; a running
+        // (unsettled) or pre-pair log entry shows the em dash.
+        timeSeconds: settled ? durationSeconds(sub.time, sub.callTime) : null,
+      },
+    })
+  }
+  return out
+}
+
 function summarizeCall(name: string, argsRaw: string): string {
   const args = argsRaw.replace(/\s+/g, ' ').trim()
   if (args === '') return name
diff --git a/packages/client/ui-trajectory/src/client/spans.ts b/packages/client/ui-trajectory/src/client/spans.ts
index 4957f3762c..585a336333 100644
--- a/packages/client/ui-trajectory/src/client/spans.ts
+++ b/packages/client/ui-trajectory/src/client/spans.ts
@@ -5,6 +5,24 @@
  */
 import type { ConversationNode, ConversationSnapshot } from '@deepseek-ai/dsh-client-runtime/client'
 
+/** One run_code sub-dispatch lane in the waterfall: real timing off the start/settle pair. */
+export interface SubSpanLane {
+  callId: string
+  name: string
+  /** Wall duration in ms; null unless both endpoints were observed (`timing: 'measured'`). */
+  durationMs: number | null
+  /**
+   * Timing provenance: `measured` = start/settle pair observed; `running` =
+   * start seen, settle pending; `unknown` = settle-only replay window (the
+   * start fell outside), so no duration claim is possible.
+   */
+  timing: 'measured' | 'running' | 'unknown'
+  /** Start offset as a fraction of the parent turn's dispatch window [0, 1). */
+  offsetFraction: number
+  /** Width as a fraction of the window (running lanes extend to the window end). */
+  widthFraction: number
+}
+
 /** One turn's worth of activity, folded from the snapshot node window. */
 export interface TurnSpan {
   turn: number
@@ -69,3 +87,61 @@ export function deriveSpanStats(spans: readonly TurnSpan[]): SpanStats {
 function hasTurn(node: ConversationNode): node is ConversationNode & { turn: number } {
   return node.kind === 'assistant' || node.kind === 'steering'
 }
+
+/**
+ * Fold the dispatch index into per-turn sub-span lanes with REAL timing: each
+ * lane's offset/width scale against its parent turn's dispatch window (first
+ * start → last settle). Running (unsettled) lanes extend to the window end
+ * with a null duration.
+ * @param nodes - snapshot nodes (locates each parent run_code call's turn).
+ * @param codeDispatches - the snapshot's dispatch index.
+ * @returns lanes keyed by turn, in start order.
+ */
+export function deriveSubSpans(
+  nodes: ConversationSnapshot['nodes'],
+  codeDispatches: ConversationSnapshot['codeDispatches'],
+): ReadonlyMap<number, readonly SubSpanLane[]> {
+  const out = new Map<number, SubSpanLane[]>()
+  if (codeDispatches.size === 0) return out
+  const turnByCall = new Map<string, number>()
+  let currentTurn = 0
+  for (const node of nodes) {
+    if (node.kind === 'assistant' || node.kind === 'steering') currentTurn = node.turn
+    if (node.kind === 'tool-result') turnByCall.set(node.callId, currentTurn)
+  }
+  for (const [parent, subs] of codeDispatches) {
+    if (subs.length === 0) continue
+    const turn = turnByCall.get(parent) ?? currentTurn
+    // A settle-only entry (callTime null: its start fell outside the replay
+    // window) anchors the window by its settle time — a real observation —
+    // but must never masquerade as a measured zero-duration span.
+    const starts: number[] = []
+    const ends: number[] = []
+    for (const sub of subs) {
+      const settled = 'kind' in sub
+      const start = settled ? sub.callTime ?? sub.time : sub.time
+      starts.push(start)
+      ends.push(settled ? sub.time : start)
+    }
+    const windowStart = Math.min(...starts)
+    const windowEnd = Math.max(...ends, windowStart + 1)
+    const windowSpan = windowEnd - windowStart
+    const lanes: SubSpanLane[] = subs.map((sub, i) => {
+      const settled = 'kind' in sub
+      const timing = settled ? (sub.callTime === null ? 'unknown' as const : 'measured' as const) : 'running' as const
+      const start = starts[i] ?? windowStart
+      const end = settled ? sub.time : windowEnd
+      return {
+        callId: sub.callId,
+        name: settled ? sub.call?.name ?? sub.callId : sub.name,
+        durationMs: timing === 'measured' ? Math.max(0, end - start) : null,
+        timing,
+        offsetFraction: (start - windowStart) / windowSpan,
+        widthFraction: Math.max((end - start) / windowSpan, 0.02),
+      }
+    })
+    const existing = out.get(turn) ?? []
+    out.set(turn, [...existing, ...lanes])
+  }
+  return out
+}
diff --git a/packages/client/ui-trajectory/src/client/views.module.css b/packages/client/ui-trajectory/src/client/views.module.css
index d3089b3568..16a853c441 100644
--- a/packages/client/ui-trajectory/src/client/views.module.css
+++ b/packages/client/ui-trajectory/src/client/views.module.css
@@ -45,3 +45,38 @@
   color: var(--dsw-alias-label-caption);
   font: var(--dsw-font-xs-13);
 }
+
+/* run_code sub-span lanes: one row per sub-dispatch under its turn row,
+   offset/width scaled to the dispatch window (real wall time). A running
+   lane pulses via reduced opacity until its settle arrives. */
+.subRow {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  margin-top: 2px;
+}
+
+.subTag {
+  flex: none;
+  width: 88px;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  color: var(--dsw-alias-label-tertiary);
+  font: var(--dsw-font-xs-13);
+}
+
+.barSub {
+  height: 8px;
+  background: var(--dsw-alias-state-business-primary);
+}
+
+.barSub[data-timing='running'] {
+  opacity: 0.45;
+}
+
+/* Settle-only replay entries: no measured span — hollow, not a solid bar. */
+.barSub[data-timing='unknown'] {
+  background: transparent;
+  border: 1px dashed var(--dsw-alias-state-business-primary);
+}
diff --git a/packages/client/ui-trajectory/tests/layout.spec.tsx b/packages/client/ui-trajectory/tests/layout.spec.tsx
index 9773f6fe57..b74782a4c4 100644
--- a/packages/client/ui-trajectory/tests/layout.spec.tsx
+++ b/packages/client/ui-trajectory/tests/layout.spec.tsx
@@ -70,7 +70,7 @@ describe('deriveTrajectoryLayout', () => {
         content: [{ type: 'text', text: 'a.txt' }], isError: false, callView: null, resultView: null,
       },
     ] as unknown as ConversationSnapshot['nodes']
-    const turns = deriveTrajectoryLayout({ nodes, partial: null, runningCalls: [] })
+    const turns = deriveTrajectoryLayout({ codeDispatches: new Map(), nodes, partial: null, runningCalls: [] })
     expect(turns).toHaveLength(1)
     expect(turns[0]?.turn).toBe(1)
     const kinds = turns[0]?.groups.flatMap((g) => g.cells.map((c) => c.kind))
@@ -86,6 +86,7 @@ describe('deriveTrajectoryLayout', () => {
 
   it('adds runningCalls not already present and leaves their time blank', () => {
     const turns = deriveTrajectoryLayout({
+      codeDispatches: new Map(),
       nodes: [] as unknown as ConversationSnapshot['nodes'],
       partial: null,
       runningCalls: [{
@@ -111,7 +112,7 @@ describe('deriveTrajectoryLayout', () => {
         usage: { inputTokens: 1, outputTokens: 2, reasoningTokens: 3 },
       },
     ] as unknown as ConversationSnapshot['nodes']
-    const turns = deriveTrajectoryLayout({ nodes, partial: null, runningCalls: [] })
+    const turns = deriveTrajectoryLayout({ codeDispatches: new Map(), nodes, partial: null, runningCalls: [] })
     const cells = turns[0]?.groups.flatMap((g) => g.cells) ?? []
     expect(cells.find((c) => c.kind === 'message')?.timeSeconds).toBeNull()
     expect(turns[0]?.groups.find((g) => g.title === 'Step 1')?.description).toBeUndefined()
@@ -137,7 +138,7 @@ describe('deriveTrajectoryLayout', () => {
         content: [], isError: false, callView: null, resultView: null,
       },
     ] as unknown as ConversationSnapshot['nodes']
-    const turns = deriveTrajectoryLayout({ nodes, partial: null, runningCalls: [] })
+    const turns = deriveTrajectoryLayout({ codeDispatches: new Map(), nodes, partial: null, runningCalls: [] })
     expect(turns[0]?.groups[0]?.description).toBe('2.9s bash×2')
   })
 
@@ -154,7 +155,7 @@ describe('deriveTrajectoryLayout', () => {
         blocks: [{ kind: 'text', text: 'ok2' }],
       },
     ] as unknown as ConversationSnapshot['nodes']
-    const turns = deriveTrajectoryLayout({ nodes, partial: null, runningCalls: [] })
+    const turns = deriveTrajectoryLayout({ codeDispatches: new Map(), nodes, partial: null, runningCalls: [] })
     expect(turns.map((t) => t.turn)).toEqual([1, 2])
     expect(turns[0]?.groups.flatMap((g) => g.cells.map((c) => c.text))).toEqual(['first', 'ok1'])
     expect(turns[1]?.groups.flatMap((g) => g.cells.map((c) => c.text))).toEqual(['second', 'ok2'])
@@ -168,7 +169,7 @@ describe('deriveTrajectoryLayout', () => {
         usage: { inputTokens: 11, outputTokens: 22, reasoningTokens: 3 },
       },
     ] as unknown as ConversationSnapshot['nodes']
-    const turns = deriveTrajectoryLayout({ nodes, partial: null, runningCalls: [] })
+    const turns = deriveTrajectoryLayout({ codeDispatches: new Map(), nodes, partial: null, runningCalls: [] })
     const message = turns[0]?.groups.flatMap((g) => g.cells).find((c) => c.kind === 'message')
     expect(message).toMatchObject({
       text: '', input: 11, output: 22, think: 3,
@@ -196,7 +197,7 @@ describe('deriveTrajectoryLayout', () => {
         blocks: [{ kind: 'text', text: 'done' }],
       },
     ] as unknown as ConversationSnapshot['nodes']
-    const turns = deriveTrajectoryLayout({ nodes, partial: null, runningCalls: [] })
+    const turns = deriveTrajectoryLayout({ codeDispatches: new Map(), nodes, partial: null, runningCalls: [] })
     const message = turns[0]?.groups
       .flatMap((g) => g.cells)
       .find((c) => c.kind === 'message' && c.text === 'done')
@@ -204,3 +205,51 @@ describe('deriveTrajectoryLayout', () => {
     expect(message?.timeSeconds).toBe(1)
   })
 })
+
+describe('run_code sub-dispatch cells', () => {
+  const runCodeNodes = [
+    {
+      kind: 'assistant', seq: 2, time: 6_000, turn: 1, step: 1,
+      blocks: [
+        { kind: 'tool-call', callId: 'p1', name: 'run_code', argsRaw: '{"code":"…","description":"批量读取"}' },
+      ],
+    },
+    {
+      kind: 'tool-result', seq: 3, time: 9_000, callId: 'p1',
+      call: { name: 'run_code', argsRaw: '{"code":"…","description":"批量读取"}' }, callTime: 6_200,
+      content: [{ type: 'text', text: 'done' }], isError: false, callView: null, resultView: null,
+    },
+  ] as unknown as ConversationSnapshot['nodes']
+
+  const settledSub = (n: number, name: string, start: number, end: number) => ({
+    kind: 'tool-result' as const, seq: 100 + n, time: end,
+    callId: `p1:code:${n}`,
+    call: { name, argsRaw: '{"x":1}' }, callTime: start,
+    content: [{ type: 'text' as const, text: 'ok' }], isError: false, callView: null, resultView: null,
+  })
+
+  it('nests settled sub-cells after their parent Tool cell with real durations', () => {
+    const codeDispatches = new Map([['p1', [
+      settledSub(1, 'bash', 6_300, 7_300),
+      settledSub(2, 'read', 7_300, 7_800),
+    ]]]) as unknown as ConversationSnapshot['codeDispatches']
+    const turns = deriveTrajectoryLayout({ codeDispatches, nodes: runCodeNodes, partial: null, runningCalls: [] })
+    const cells = turns[0]!.groups.flatMap((g) => g.cells)
+    expect(cells.map((c) => c.kind)).toEqual(['tool', 'subtool', 'subtool'])
+    // Sequential indexes across the interleave; durations from the pair times.
+    expect(cells.map((c) => c.index)).toEqual([1, 2, 3])
+    expect(cells[1]).toMatchObject({ text: 'bash · {"x":1}', timeSeconds: 1 })
+    expect(cells[2]).toMatchObject({ timeSeconds: 0.5 })
+  })
+
+  it('a running (unsettled) sub-call renders a subtool cell with blank time', () => {
+    const running = {
+      callId: 'p1:code:1', name: 'grep', argsRaw: '{"pattern":"x"}',
+      turn: 0, step: 0, time: 6_400, callView: null,
+    }
+    const codeDispatches = new Map([['p1', [running]]]) as unknown as ConversationSnapshot['codeDispatches']
+    const turns = deriveTrajectoryLayout({ codeDispatches, nodes: runCodeNodes, partial: null, runningCalls: [] })
+    const sub = turns[0]!.groups.flatMap((g) => g.cells).find((c) => c.kind === 'subtool')
+    expect(sub).toMatchObject({ text: 'grep · {"pattern":"x"}', timeSeconds: null })
+  })
+})
diff --git a/packages/client/ui-trajectory/tests/views.spec.tsx b/packages/client/ui-trajectory/tests/views.spec.tsx
index c1e6331ef6..485db395eb 100644
--- a/packages/client/ui-trajectory/tests/views.spec.tsx
+++ b/packages/client/ui-trajectory/tests/views.spec.tsx
@@ -21,7 +21,7 @@ import type { ConvViewProps, ViewTab } from '@deepseek-ai/dsh-client-ui-conversa
 import { ConversationRoot, type ConversationRootProps } from '@deepseek-ai/dsh-client-ui-conversation/src/client/skeleton/ConversationRoot.tsx'
 import { createChatStore } from '@deepseek-ai/dsh-client-ui-conversation/src/client/stores.ts'
 import { apply, inject } from '@deepseek-ai/dsh-client-ui-trajectory/client'
-import { deriveSpans, deriveSpanStats } from '@deepseek-ai/dsh-client-ui-trajectory/src/client/spans.ts'
+import { deriveSpans, deriveSpanStats, deriveSubSpans } from '@deepseek-ai/dsh-client-ui-trajectory/src/client/spans.ts'
 import { TrajectoryStatsHeader } from '@deepseek-ai/dsh-client-ui-trajectory/src/client/TrajectoryStatsHeader.tsx'
 import { TrajectoryView } from '@deepseek-ai/dsh-client-ui-trajectory/src/client/TrajectoryView.tsx'
 import { WaterfallView } from '@deepseek-ai/dsh-client-ui-trajectory/src/client/WaterfallView.tsx'
@@ -54,7 +54,7 @@ const NODES = [
 
 function fakeSession(nodes: ConversationSnapshot['nodes']) {
   const store = createSnapshotStore({
-    nodes, partial: null, runningCalls: [] as ConversationSnapshot['runningCalls'],
+    nodes, partial: null, runningCalls: [] as ConversationSnapshot['runningCalls'], codeDispatches: new Map(),
   })
   return { store, useSession: bindSnapshotSelector(store) as unknown as UseSession<ConversationSnapshot> }
 }
@@ -117,7 +117,7 @@ function tabsOf(slots: SlotsService): ViewTab[] {
 function mount(slots: SlotsService, nodes: ConversationSnapshot['nodes'] = NODES) {
   const sessionSnapshot = createSnapshotStore({
     running: false, removed: false, promptError: null, nodes,
-    partial: null, runningCalls: [] as ConversationSnapshot['runningCalls'],
+    partial: null, runningCalls: [] as ConversationSnapshot['runningCalls'], codeDispatches: new Map(),
   })
   const useSession = bindSnapshotSelector(sessionSnapshot) as unknown as UseSession<ConversationSnapshot>
   const chat = createChatStore().create()
@@ -260,3 +260,115 @@ describe('node half', () => {
     expect(nodeApply()).toBeUndefined()
   })
 })
+
+describe('deriveSubSpans (waterfall lanes)', () => {
+  const dispatchNodes = [
+    { kind: 'assistant', seq: 2, time: 6_000, turn: 3, step: 1, blocks: [] },
+    {
+      kind: 'tool-result', seq: 3, time: 9_000, callId: 'p1',
+      call: { name: 'run_code', argsRaw: '{}' }, callTime: 6_100,
+      content: [], isError: false, callView: null, resultView: null,
+    },
+  ] as unknown as ConversationSnapshot['nodes']
+
+  it('scales settled lanes into the dispatch window with real durations', () => {
+    const codeDispatches = new Map([['p1', [
+      {
+        kind: 'tool-result', seq: 101, time: 7_000, callId: 'p1:code:1',
+        call: { name: 'bash', argsRaw: '{}' }, callTime: 6_200,
+        content: [], isError: false, callView: null, resultView: null,
+      },
+      {
+        kind: 'tool-result', seq: 102, time: 8_200, callId: 'p1:code:2',
+        call: { name: 'read', argsRaw: '{}' }, callTime: 7_000,
+        content: [], isError: false, callView: null, resultView: null,
+      },
+    ]]]) as unknown as ConversationSnapshot['codeDispatches']
+    const lanes = deriveSubSpans(dispatchNodes, codeDispatches)
+    const turn3 = lanes.get(3)
+    expect(turn3).toHaveLength(2)
+    // Window = 6200..8200 (2000ms). bash: 0..0.4; read: 0.4..1.0.
+    expect(turn3?.[0]).toMatchObject({ name: 'bash', durationMs: 800, timing: 'measured', offsetFraction: 0 })
+    expect(turn3?.[0]?.widthFraction).toBeCloseTo(0.4)
+    expect(turn3?.[1]).toMatchObject({ name: 'read', durationMs: 1200 })
+    expect(turn3?.[1]?.offsetFraction).toBeCloseTo(0.4)
+  })
+
+  it('a running lane extends to the window end with a null duration', () => {
+    const codeDispatches = new Map([['p1', [
+      {
+        kind: 'tool-result', seq: 101, time: 8_000, callId: 'p1:code:1',
+        call: { name: 'bash', argsRaw: '{}' }, callTime: 6_200,
+        content: [], isError: false, callView: null, resultView: null,
+      },
+      { callId: 'p1:code:2', name: 'grep', argsRaw: '{}', turn: 0, step: 0, time: 7_000, callView: null },
+    ]]]) as unknown as ConversationSnapshot['codeDispatches']
+    const lanes = deriveSubSpans(dispatchNodes, codeDispatches)
+    const running = lanes.get(3)?.find((lane) => lane.name === 'grep')
+    expect(running).toMatchObject({ durationMs: null, timing: 'running' })
+    // Extends from its start to the window end.
+    expect(running!.offsetFraction + running!.widthFraction).toBeCloseTo(1)
+  })
+
+  it('a settle-only entry (null callTime) is unknown timing, never a measured 0 ms', () => {
+    const codeDispatches = new Map([['p1', [
+      {
+        kind: 'tool-result', seq: 101, time: 8_000, callId: 'p1:code:1',
+        call: { name: 'bash', argsRaw: '{}' }, callTime: null,
+        content: [], isError: false, callView: null, resultView: null,
+      },
+    ]]]) as unknown as ConversationSnapshot['codeDispatches']
+    const lane = deriveSubSpans(dispatchNodes, codeDispatches).get(3)?.[0]
+    expect(lane).toMatchObject({ durationMs: null, timing: 'unknown' })
+  })
+
+  it('waterfall renders sub-span lanes under the owning turn row', () => {
+    const codeDispatches = new Map([['p1', [
+      {
+        kind: 'tool-result', seq: 101, time: 8_000, callId: 'p1:code:1',
+        call: { name: 'bash', argsRaw: '{}' }, callTime: 6_200,
+        content: [], isError: false, callView: null, resultView: null,
+      },
+    ]]]) as unknown as ConversationSnapshot['codeDispatches']
+    const store = createSnapshotStore({
+      nodes: dispatchNodes, partial: null,
+      runningCalls: [] as ConversationSnapshot['runningCalls'], codeDispatches,
+    })
+    const props = {
+      sessionId: SID,
+      useSession: bindSnapshotSelector(store) as unknown as UseSession<ConversationSnapshot>,
+      useSessions: emptySessions(),
+      useWorkspaces: emptyWorkspaces(),
+    } as unknown as ConvViewProps
+    const view = render(createElement(WaterfallView as FC<ConvViewProps>, props))
+    const lane = view.container.querySelector('[data-subspan]')
+    expect(lane).not.toBeNull()
+    expect(lane!.textContent).toContain('bash')
+    expect(lane!.querySelector('[title*="1.80s"]')).not.toBeNull()
+    expect(lane!.querySelector('[data-timing="measured"]')).not.toBeNull()
+  })
+
+  it('waterfall labels a settle-only lane as duration unknown', () => {
+    const codeDispatches = new Map([['p1', [
+      {
+        kind: 'tool-result', seq: 101, time: 8_000, callId: 'p1:code:1',
+        call: { name: 'read', argsRaw: '{}' }, callTime: null,
+        content: [], isError: false, callView: null, resultView: null,
+      },
+    ]]]) as unknown as ConversationSnapshot['codeDispatches']
+    const store = createSnapshotStore({
+      nodes: dispatchNodes, partial: null,
+      runningCalls: [] as ConversationSnapshot['runningCalls'], codeDispatches,
+    })
+    const props = {
+      sessionId: SID,
+      useSession: bindSnapshotSelector(store) as unknown as UseSession<ConversationSnapshot>,
+      useSessions: emptySessions(),
+      useWorkspaces: emptyWorkspaces(),
+    } as unknown as ConvViewProps
+    const view = render(createElement(WaterfallView as FC<ConvViewProps>, props))
+    const bar = view.container.querySelector('[data-timing="unknown"]')
+    expect(bar).not.toBeNull()
+    expect(bar!.getAttribute('title')).toContain('duration unknown')
+  })
+})
diff --git a/packages/client/web/src/base.css b/packages/client/web/src/base.css
index 991a03bbca..b8449634eb 100644
--- a/packages/client/web/src/base.css
+++ b/packages/client/web/src/base.css
@@ -1,9 +1,10 @@
 /* Shell-owned global base: full-height mount plus the theme token sheets.
- * The three ui-theme sheets are the sole token source (--dsw-*); the shell
+ * The four ui-theme sheets are the sole token source (--dsw-*); the shell
  * links them here so tokens exist before any plugin CSS lands. */
 @import '@deepseek-ai/dsh-client-ui-theme/styles/base.css';
 @import '@deepseek-ai/dsh-client-ui-theme/styles/design-platform.css';
 @import '@deepseek-ai/dsh-client-ui-theme/styles/gradient-shadow-text.css';
+@import '@deepseek-ai/dsh-client-ui-theme/styles/shiki.css';
 
 html,
 body,
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index fc4b87c934..e5f104e115 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -930,6 +930,9 @@ importers:
 
   packages/client/ui-primitives:
     dependencies:
+      '@shikijs/langs':
+        specifier: ^4.3.1
+        version: 4.3.1
       clsx:
         specifier: ^2.0.0
         version: 2.1.1
@@ -945,6 +948,9 @@ importers:
       remark-gfm:
         specifier: ^4.0.1
         version: 4.0.1
+      shiki:
+        specifier: ^4.3.1
+        version: 4.3.1
     devDependencies:
       '@deepseek-ai/dsh-invariants':
         specifier: workspace:^
@@ -6770,24 +6776,52 @@ packages:
   '@shikijs/core@2.5.0':
     resolution: {integrity: sha512-uu/8RExTKtavlpH7XqnVYBrfBkUc20ngXiX9NSrBhOVZYv/7XQRKUyhtkeflY5QsxC0GbJThCerruZfsUaSldg==}
 
+  '@shikijs/core@4.3.1':
+    resolution: {integrity: sha512-ANMDxuaPsNMdDC1m4vfvhlDmJweMwkE5XitTwrq2rWHx5jM+dlm4MmHt2PP6t0uejfR77SuhrhJ0zEijIF/uhA==}
+    engines: {node: '>=20'}
+
   '@shikijs/engine-javascript@2.5.0':
     resolution: {integrity: sha512-VjnOpnQf8WuCEZtNUdjjwGUbtAVKuZkVQ/5cHy/tojVVRIRtlWMYVjyWhxOmIq05AlSOv72z7hRNRGVBgQOl0w==}
 
+  '@shikijs/engine-javascript@4.3.1':
+    resolution: {integrity: sha512-JBItcnPuYq7jVJdZo/vMj94r+szT7XEjHFX+mvFDGSEIbVAXAGyHAHzhbWzpGOwYidCZrErJLLgn2PVeiokHnQ==}
+    engines: {node: '>=20'}
+
   '@shikijs/engine-oniguruma@2.5.0':
     resolution: {integrity: sha512-pGd1wRATzbo/uatrCIILlAdFVKdxImWJGQ5rFiB5VZi2ve5xj3Ax9jny8QvkaV93btQEwR/rSz5ERFpC5mKNIw==}
 
+  '@shikijs/engine-oniguruma@4.3.1':
+    resolution: {integrity: sha512-OXyNMzg0pews+msMj4cHeqT4xiYKKvbnn6VbdAXxfoFl3SSx4fJTc8FadECuc5/H9p3BzhNAoAUXKwAu9rWYhg==}
+    engines: {node: '>=20'}
+
   '@shikijs/langs@2.5.0':
     resolution: {integrity: sha512-Qfrrt5OsNH5R+5tJ/3uYBBZv3SuGmnRPejV9IlIbFH3HTGLDlkqgHymAlzklVmKBjAaVmkPkyikAV/sQ1wSL+w==}
 
+  '@shikijs/langs@4.3.1':
+    resolution: {integrity: sha512-m0l9nsDqgBHvbZbk7A0/kXz/impK3uB/c6rAn6Gpg/uPtdZRQ+alsN/17MU5thb68XTj/4DxkZAotrM0GGSpDQ==}
+    engines: {node: '>=20'}
+
+  '@shikijs/primitive@4.3.1':
+    resolution: {integrity: sha512-CXQRQOYy1leqQ8ceTeJdmXv/bsUY++6QyLpXJ94LZAAYj5X2SKRdc5ipguv4NPyGVKItB2PPwUpRNe0Sjh5S1A==}
+    engines: {node: '>=20'}
+
   '@shikijs/themes@2.5.0':
     resolution: {integrity: sha512-wGrk+R8tJnO0VMzmUExHR+QdSaPUl/NKs+a4cQQRWyoc3YFbUzuLEi/KWK1hj+8BfHRKm2jNhhJck1dfstJpiw==}
 
+  '@shikijs/themes@4.3.1':
+    resolution: {integrity: sha512-dgpoJ4WqNi2yTmizQHBJ5zcX6j2lE6icN/0yt4l1kkf16jrY/pwPLoTb1ETsWMz0OBLf9ZNvwmxft+cH+N9qSA==}
+    engines: {node: '>=20'}
+
   '@shikijs/transformers@2.5.0':
     resolution: {integrity: sha512-SI494W5X60CaUwgi8u4q4m4s3YAFSxln3tzNjOSYqq54wlVgz0/NbbXEb3mdLbqMBztcmS7bVTaEd2w0qMmfeg==}
 
   '@shikijs/types@2.5.0':
     resolution: {integrity: sha512-ygl5yhxki9ZLNuNpPitBWvcy9fsSKKaRuO4BAlMyagszQidxcpLAr0qiW/q43DtSIDxO6hEbtYLiFZNXO/hdGw==}
 
+  '@shikijs/types@4.3.1':
+    resolution: {integrity: sha512-CHFxE0jztBIZRHH6gxXE7DXUCFXjReEGxZ/j0rfSLGKZuwp2xBYycEP14875DSa9KLL/6700oxIq6oO6ef9K2g==}
+    engines: {node: '>=20'}
+
   '@shikijs/vscode-textmate@10.0.2':
     resolution: {integrity: sha512-83yeghZ2xxin3Nj8z1NMd/NCuca+gsYXswywDy5bHvwlWL8tpTQmzGeUuHd9FC3E/SBEMvzJRwWEOz5gGes9Qg==}
 
@@ -8931,9 +8965,15 @@ packages:
   once@1.4.0:
     resolution: {integrity: sha512-lNaJgI+2Q5URQBkccEKHTQOPaXdUxnZZElQTZY0MFUAuaEqe1E+Nyvgdz/aIyNi6Z9MzO5dv1H8n58/GELp3+w==}
 
+  oniguruma-parser@0.12.2:
+    resolution: {integrity: sha512-6HVa5oIrgMC6aA6WF6XyyqbhRPJrKR02L20+2+zpDtO5QAzGHAUGw5TKQvwi5vctNnRHkJYmjAhRVQF2EKdTQw==}
+
   oniguruma-to-es@3.1.1:
     resolution: {integrity: sha512-bUH8SDvPkH3ho3dvwJwfonjlQ4R80vjyvrU8YpxuROddv55vAEJrTuCuCVUhhsHbtlD9tGGbaNApGQckXhS8iQ==}
 
+  oniguruma-to-es@4.3.6:
+    resolution: {integrity: sha512-csuQ9x3Yr0cEIs/Zgx/OEt9iBw9vqIunAPQkx19R/fiMq2oGVTgcMqO/V3Ybqefr1TBvosI6jU539ksaBULJyA==}
+
   openai@6.26.0:
     resolution: {integrity: sha512-zd23dbWTjiJ6sSAX6s0HrCZi41JwTA1bQVs0wLQPZ2/5o2gxOJA5wh7yOAUgwYybfhDXyhwlpeQf7Mlgx8EOCA==}
     hasBin: true
@@ -9290,6 +9330,10 @@ packages:
   shiki@2.5.0:
     resolution: {integrity: sha512-mI//trrsaiCIPsja5CNfsyNOqgAZUb6VpJA+340toL42UpzQlXpwRV9nch69X6gaUxrr9kaOOa6e3y3uAkGFxQ==}
 
+  shiki@4.3.1:
+    resolution: {integrity: sha512-oR+qDVi2OjX1tmDpyv+3KviX01KzO6Af+0NNnKnsp9491UEGz2YpxTuJboS/6VhYpTdqzmuJBuiTlrAWWJAssw==}
+    engines: {node: '>=20'}
+
   side-channel-list@1.0.1:
     resolution: {integrity: sha512-mjn/0bi/oUURjc5Xl7IaWi/OJJJumuoJFQJfDDyO46+hBWsfaVM65TBHq2eoZBhzl9EchxOijpkbRC8SVBQU0w==}
     engines: {node: '>= 0.4'}
@@ -11407,25 +11451,58 @@ snapshots:
       '@types/hast': 3.0.5
       hast-util-to-html: 9.0.5
 
+  '@shikijs/core@4.3.1':
+    dependencies:
+      '@shikijs/primitive': 4.3.1
+      '@shikijs/types': 4.3.1
+      '@shikijs/vscode-textmate': 10.0.2
+      '@types/hast': 3.0.5
+      hast-util-to-html: 9.0.5
+
   '@shikijs/engine-javascript@2.5.0':
     dependencies:
       '@shikijs/types': 2.5.0
       '@shikijs/vscode-textmate': 10.0.2
       oniguruma-to-es: 3.1.1
 
+  '@shikijs/engine-javascript@4.3.1':
+    dependencies:
+      '@shikijs/types': 4.3.1
+      '@shikijs/vscode-textmate': 10.0.2
+      oniguruma-to-es: 4.3.6
+
   '@shikijs/engine-oniguruma@2.5.0':
     dependencies:
       '@shikijs/types': 2.5.0
       '@shikijs/vscode-textmate': 10.0.2
 
+  '@shikijs/engine-oniguruma@4.3.1':
+    dependencies:
+      '@shikijs/types': 4.3.1
+      '@shikijs/vscode-textmate': 10.0.2
+
   '@shikijs/langs@2.5.0':
     dependencies:
       '@shikijs/types': 2.5.0
 
+  '@shikijs/langs@4.3.1':
+    dependencies:
+      '@shikijs/types': 4.3.1
+
+  '@shikijs/primitive@4.3.1':
+    dependencies:
+      '@shikijs/types': 4.3.1
+      '@shikijs/vscode-textmate': 10.0.2
+      '@types/hast': 3.0.5
+
   '@shikijs/themes@2.5.0':
     dependencies:
       '@shikijs/types': 2.5.0
 
+  '@shikijs/themes@4.3.1':
+    dependencies:
+      '@shikijs/types': 4.3.1
+
   '@shikijs/transformers@2.5.0':
     dependencies:
       '@shikijs/core': 2.5.0
@@ -11436,6 +11513,11 @@ snapshots:
       '@shikijs/vscode-textmate': 10.0.2
       '@types/hast': 3.0.5
 
+  '@shikijs/types@4.3.1':
+    dependencies:
+      '@shikijs/vscode-textmate': 10.0.2
+      '@types/hast': 3.0.5
+
   '@shikijs/vscode-textmate@10.0.2': {}
 
   '@smithy/core@3.24.7':
@@ -13998,12 +14080,20 @@ snapshots:
     dependencies:
       wrappy: 1.0.2
 
+  oniguruma-parser@0.12.2: {}
+
   oniguruma-to-es@3.1.1:
     dependencies:
       emoji-regex-xs: 1.0.0
       regex: 6.1.0
       regex-recursion: 6.0.2
 
+  oniguruma-to-es@4.3.6:
+    dependencies:
+      oniguruma-parser: 0.12.2
+      regex: 6.1.0
+      regex-recursion: 6.0.2
+
   openai@6.26.0(ws@8.21.0)(zod@4.4.3):
     optionalDependencies:
       ws: 8.21.0
@@ -14504,6 +14594,17 @@ snapshots:
       '@shikijs/vscode-textmate': 10.0.2
       '@types/hast': 3.0.5
 
+  shiki@4.3.1:
+    dependencies:
+      '@shikijs/core': 4.3.1
+      '@shikijs/engine-javascript': 4.3.1
+      '@shikijs/engine-oniguruma': 4.3.1
+      '@shikijs/langs': 4.3.1
+      '@shikijs/themes': 4.3.1
+      '@shikijs/types': 4.3.1
+      '@shikijs/vscode-textmate': 10.0.2
+      '@types/hast': 3.0.5
+
   side-channel-list@1.0.1:
     dependencies:
       es-errors: 1.3.0