diff --git a/.agents/notes/implemented/feature/2026-07-30-web-read-card.i18n.yaml b/.agents/notes/implemented/feature/2026-07-30-web-read-card.i18n.yaml
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+# 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 .agents/notes/implemented/feature/2026-07-30-web-read-card.md
+2026-07-30-web-read-card.md: 1fb3d61a113d26f6daf023fc791f3638055b5be0
+2026-07-30-web-read-card.zh.md: 946bcca95bcc9bb50beb1ef22e77e4a21728b538
diff --git a/.agents/notes/implemented/feature/2026-07-30-web-read-card.md b/.agents/notes/implemented/feature/2026-07-30-web-read-card.md
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+++ b/.agents/notes/implemented/feature/2026-07-30-web-read-card.md
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+# Agent Note: Read card — the read tool's structured line window reaches the client
+
+Status: implemented
+
+English | [中文](2026-07-30-web-read-card.zh.md)
+
+## Problem
+
+The `read` tool returns a canonical output object `{ path, offset, lines: [{ number, text }], totalLines }`, but its presentation collapsed that structure. `presentCall` declared a `GenericCallView` (`kind: 'read'`, a follow-along location) and `presentResult` returned a `GenericResultView` whose only content was the model-facing text with its `<path>…</path><type>file</type><content>…</content>` envelope stripped. A UI receiving that view saw one flattened text block: the line numbers were baked into the text as `N: ` prefixes, the file's language was unknown, and `totalLines` was gone. There was no way for a capable client to render a read the way it renders a diff — a line-numbered, syntax-highlighted code view with the line-number gutter separate from the content.
+
+The structured data cannot be recovered downstream. A tool result on the wire carries only the model-facing `ContentBlock[]` (the rendered text) plus an opaque `meta`; the canonical output object stays in the tool and never reaches the client or the session log. So a client that wants the line array, the total, and a language hint cannot parse them back out of the `N: text` text — the tool has to project them onto a channel that persists.
+
+## Decision
+
+Add a fourth `card` tag, `read`, to the [render-intent union](../architecture/2026-07-02-tool-render-intent-union.md) — result-side only. `ToolResultView` gains `ReadResultView { card: 'read'; title?; path; lines: ReadFileLine[]; totalLines; lang?; content? }`; `ReadFileLine { number; text }` is the shared line unit. `ToolCallView` is untouched: the pending state stays a `GenericCallView` (`kind: 'read'`) because a call carries no file content until `execute` returns, so there is nothing structured to show at call time. This diverges from the bash terminal card, which tags both sides — a terminal call already carries its command and cwd at call time, a read call carries neither content nor total, so tagging the call side would add an empty variant.
+
+The read tool projects the structured window through `output.presentationMeta`, the same persisted channel write/edit use for their applied-diff hunks ([canonical tool output contract](../architecture/2026-07-20-canonical-tool-output-contract.md)). `presentationMeta` runs once for a top-level surface call, returns `{ path, offset, lines, totalLines, lang? }` as JSON the session validates and stores on the result's `meta`, and `presentResult` narrows that meta back into the `ReadResultView` on both live and replay paths. `offset` (the 1-based first line the window requested) rides along because a byte cap below the first selected line yields an empty `lines` array with a positive `totalLines`; without the persisted `offset` a replayed card of such a window could not report where it starts or where a continuation resumes, and the last-line and re-parse fallbacks are both lossy. Without this channel the line array and total would be unreachable: the raw output object is not on the wire, and re-parsing the `N: text` text is lossy and fragile against the truncation footer.
+
+`presentResult` returns `undefined` — the generic fallback — whenever the meta is absent or malformed (`readMetaFromMeta` narrows it defensively, so a replay of an older logged result never throws), whenever the result is an error, and whenever the single text block is not the read envelope. A pre-card logged result — a valid read envelope with no persisted `meta`, recorded before this card existed — takes that same `undefined` path deliberately: the client falls back to the raw `result.content`, so it shows the enveloped `<path>/<type>/<content>` text rather than the envelope-stripped generic card the old presenter returned. This is the accepted degradation under the [pre-release stance](../../../../AGENTS.md#pre-release-stance-foundation-over-blast-radius): reject the old on-disk format rather than add an envelope-stripping compatibility branch, since this PR re-records every published fixture and the session format promises no backward compatibility. On the success path `presentResult` carries `content` (the envelope-stripped text) alongside the structured fields, so a UI without the read capability, including the current TUI, renders the file text through the generic/default card arm exactly as before. The TUI's `renderBody` switch (`packages/ui/tui/src/components/transcript.ts`) is not `assertNever`-exhaustive: `terminal` and `diff` have arms and everything else falls through to the generic arm, which reads `view.content`. That default arm alone was not enough: `render()` sets `genericContent` — and with it the dim-Markdown `dimBody` treatment — on a separate gate that was `card === 'generic'` only, so a `read` card would have kept the text but lost its dim styling. The gate now admits `card: 'read'` too, taking `content` down the same dim-Markdown path, so a read renders in the TUI exactly as it did before the read card existed. Beyond that one gate the TUI needs no read-specific code.
+
+### Language hint derivation
+
+`langFromPath` (in `read-render.ts`) maps a file extension to a syntax-highlighting language id through a small fixed table (`LANG_BY_EXTENSION`) covering common source, config, and markup extensions. It reads the extension after the last path segment and last dot, is case-insensitive, and returns `undefined` for a dotfile (`.gitignore`), an extensionless name (`/etc/hosts`), a trailing dot, and any unknown extension — the card then omits `lang` and a UI renders plain text. The table is not a tunable: it is a display hint a UI may ignore, not a deployment-varying choice, and an unknown extension degrades to plain text rather than failing. It is deliberately small rather than an exhaustive language registry; extending it is a one-line table addition.
+
+## Alternatives considered
+
+**Re-parse the `N: text` model-facing text in `presentResult`.** Rejected: the structured line array would have to be reconstructed by splitting each line on the first `: `, which is ambiguous (a line whose own text contains `: `), loses the exact `totalLines` (the footer only states it in some branches), and breaks the moment the render format changes. `presentationMeta` carries the already-structured data with no re-parse.
+
+**Tag the call side too (`ReadCallView`), mirroring the terminal card's both-sides symmetry.** Rejected: a read call has no content, no line array, and no total until it executes — a call-side read card would be an empty variant duplicating what `GenericCallView` (`kind: 'read'`, follow-along location) already expresses. The terminal card tags both sides because a terminal call genuinely carries call-time data (command, cwd); a read call does not.
+
+**Put the structured window in a new service or a side channel instead of `meta`.** Rejected: `meta` is the established persisted presentation channel (write/edit's applied diffs ride it), it replays for free with the session log, and it needs no new plumbing. A service would reinvent persistence and replay that the event log already provides.
+
+**A merge-extensible union instead of a closed tag.** Rejected for the same reason the [render-intent union](../architecture/2026-07-02-tool-render-intent-union.md) closed: a new card needs consuming code to render it, so a variant a consumer silently drops is worse than a compile error. Adding `read` to the closed union is the sanctioned way to extend it — each consumer that switches on `card` keeps compiling because the new member falls through its generic default, and a consumer that wants the rich view adds its own arm.
+
+## Consequences
+
+`ToolResultView` has a fourth member. Every consumer that switches on `card` keeps compiling: the TUI and the current Web client route an unknown card to their generic path, and the read card carries `content` so that path shows the file text. The Web frontend that renders the line-numbered, syntax-highlighted view from `lines`/`lang`/`totalLines` is a separate follow-up PR; this PR is the backend that makes the data reachable. Until that lands, a read renders exactly as it did before (the generic text card) everywhere.
+
+The read tool now computes `presentationMeta` for every top-level read, a small per-call projection (a `lines.map` and one `langFromPath` call) on data already in hand. The meta is persisted with the session log, so a read result is slightly larger on disk — the line array it already rendered as text, now also structured.
+
+## Testing
+
+`packages/fs/tool-fs/tests/read-render.spec.ts` unit-tests `langFromPath` (known extensions case-insensitively, extension read after the last segment and last dot, and the `undefined` cases: dotfile, extensionless, trailing dot, unknown) and `readMetaFromMeta` (a well-formed narrow with and without `lang`, and every rejection: non-object, array, missing or wrong-typed `path`/`totalLines`/`lines`, a malformed line entry, a non-string `lang`, and — because the function narrows the opaque persisted `meta` boundary — the semantically invalid paths a well-typed replayed JSON can still carry: an `offset` that is not a 1-based integer, a first line `number` below `offset`, a line `number` that is not a 1-based integer (`0`, `1.5`, `NaN`, `Infinity`), a `totalLines` that is not a non-negative integer (`-1`, `1.5`, `NaN`), and lines whose numbers duplicate, decrease, or exceed `totalLines`; it also narrows an empty window at a positive `offset` (a byte cap below the first selected line). `packages/fs/tool-fs/tests/tools.spec.ts` pins the tool wiring: `execute` attaches the structured window (with and without a `lang` hint) as `meta`, `presentResult` narrows it into a `card: 'read'` view carrying the envelope-stripped `content`, and the decline paths (error result, non-single-text content, malformed envelope with valid meta, and valid envelope with absent or malformed meta) all fall back to `undefined`. Both changed source files hold per-file 100% coverage. This PR carries the snapshot evidence for the persisted meta and the extended union, not for a new rendered view: the re-recorded ACP session fixtures (`fs-read`, `fs-read-window`, `fs-edit`, `fs-policy-reject`, `fs-write-overwrite`, `parallel-tool-calls`, `workspace-context`, `workspace-edit`) pin the persisted read `meta` (with `{{cwd}}`-tokenized paths), and `cordis-inspect-jsdoc` pins the four-member `ToolResultView` union. The keyless snapshot and assembled-application transcript for the rendered read card belong to the follow-up Web PR that consumes the view, since this PR adds no new product-user-visible rendering — the TUI routes the read card through its existing generic dim-Markdown fallback (`transcript.ts` treats `card: 'read'` like `card: 'generic'`), so its output is unchanged. The `apps/cli` `parallel-file-reads` terminal golden (`apps/cli/tests/snapshots/parallel-file-reads/terminal.expected.txt`) pins exactly that: a real replay executes the read tool, renders it through the new `card: 'read'` gate, and the golden's dim-Markdown rows are byte-for-byte what a generic read produced before this card existed.
+
+## Related
+
+- [Tagged render-intent union for tool-call presentation](../architecture/2026-07-02-tool-render-intent-union.md) — the `card`-tagged vocabulary this extends with the `read` result arm.
+- [Canonical tool output contract](../architecture/2026-07-20-canonical-tool-output-contract.md) — owns the `presentationMeta` persisted channel this projects the read window onto.
+- [Web terminal card](2026-07-28-web-terminal-card.md) — the precedent for a client consuming a structured card; the read card follows the same producer pattern, result-side only.
diff --git a/.agents/notes/implemented/feature/2026-07-30-web-read-card.zh.md b/.agents/notes/implemented/feature/2026-07-30-web-read-card.zh.md
new file mode 100644
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+++ b/.agents/notes/implemented/feature/2026-07-30-web-read-card.zh.md
@@ -0,0 +1,49 @@
+# Agent Note: Read card — the read tool's structured line window reaches the client
+
+Status: implemented
+
+[English](2026-07-30-web-read-card.md) | 中文
+
+## Problem
+
+`read` 工具返回规范化输出对象 `{ path, offset, lines: [{ number, text }], totalLines }`，但它的展示层把这个结构压平了。`presentCall` 声明为 `GenericCallView`（`kind: 'read'`，一个跟随定位），`presentResult` 返回 `GenericResultView`，其唯一内容是剥掉 `<path>…</path><type>file</type><content>…</content>` 信封后的面向模型文本。收到该视图的 UI 只看到一个压平的文本块：行号以 `N: ` 前缀烘焙进文本、文件语言未知、`totalLines` 丢失。capable 客户端无法像渲染 diff 那样渲染一次 read——即带行号、语法高亮、行号槽与内容分离的代码视图。
+
+结构化数据在下游无法恢复。线上（wire）的工具结果只携带面向模型的 `ContentBlock[]`（已渲染文本）加上一个不透明的 `meta`；规范化输出对象留在工具内，从不到达客户端或会话日志。因此想要行数组、总数和语言提示的客户端无法从 `N: text` 文本里解析回它们——工具必须把它们投影到一个会持久化的通道上。
+
+## Decision
+
+给[渲染意图 union](../architecture/2026-07-02-tool-render-intent-union.md) 新增第四个 `card` 标签 `read`——仅在结果侧。`ToolResultView` 增加 `ReadResultView { card: 'read'; title?; path; lines: ReadFileLine[]; totalLines; lang?; content? }`；`ReadFileLine { number; text }` 是共享的行单元。`ToolCallView` 不动：待定状态仍是 `GenericCallView`（`kind: 'read'`），因为一次调用在 `execute` 返回前不携带文件内容，调用时没有可展示的结构。这与 bash 终端 card 不同——终端 card 两侧都打标签，因为终端调用在调用时已携带命令和 cwd，而 read 调用既无内容也无总数，给调用侧打标签只会新增一个空变体。
+
+read 工具通过 `output.presentationMeta` 投影结构化窗口，这与 write/edit 用来投影其应用 diff hunk 的持久化通道相同（[规范化工具输出契约](../architecture/2026-07-20-canonical-tool-output-contract.md)）。`presentationMeta` 对一次顶层 surface 调用运行一次，返回 `{ path, offset, lines, totalLines, lang? }` 作为会话校验并存储在结果 `meta` 上的 JSON，`presentResult` 在 live 和回放路径上都把该 meta 收窄回 `ReadResultView`。`offset`（窗口请求的 1-based 起始行）一并携带，是因为当字节上限低于首个选中行时，窗口会返回空的 `lines` 数组而 `totalLines` 为正；没有持久化的 `offset`，这类窗口的回放 card 就无法报告它从哪行开始、或续读应从哪行继续，而末行推断与文本重解析两种兜底都有损。没有这个通道，行数组和总数就无法触及：原始输出对象不在线上，而重新解析 `N: text` 文本既有损又对截断脚注脆弱。
+
+`presentResult` 在以下情况返回 `undefined`——即 generic 回退：meta 缺失或畸形（`readMetaFromMeta` 防御性收窄它，因此回放旧的已记录结果永不抛错）、结果是错误、以及单个文本块不是 read 信封。本 card 出现之前记录的结果——信封合法但无持久化 `meta`——有意走同一条 `undefined` 路径：客户端回退到原始 `result.content`，因此显示带 `<path>/<type>/<content>` 信封的原文，而非旧展示器返回的剥信封 generic card。这是 [pre-release 立场](../../../../AGENTS.md#pre-release-stance-foundation-over-blast-radius)下接受的降级：拒绝旧的磁盘格式，而非加一个剥信封的兼容分支——本 PR 已重录全部已发布 fixtures，且 session 格式不承诺向后兼容。在成功路径上，`presentResult` 在结构化字段之外携带 `content`（剥信封后的文本），因此不具备 read 能力的 UI（包括当前的 TUI）通过 generic/default card 分支渲染文件文本，与之前完全一致。TUI 的 `renderBody` switch（`packages/ui/tui/src/components/transcript.ts`）不是 `assertNever` 穷尽的：`terminal` 和 `diff` 有分支，其余都落入 generic 分支，该分支读取 `view.content`。仅有该默认分支还不够：`render()` 在一个独立门控上设置 `genericContent`（连同 dim-Markdown 的 `dimBody` 处理），该门控原先只判 `card === 'generic'`，因此 `read` card 虽保留文本却会丢失 dim 样式。现在该门控也接纳 `card: 'read'`，让 `content` 走同一条 dim-Markdown 路径，因此 read 在 TUI 中的渲染与 read card 出现之前完全一致。除这一处门控外，TUI 无需 read 专属代码。
+
+### 语言提示推导
+
+`langFromPath`（在 `read-render.ts` 中）通过一张固定小表（`LANG_BY_EXTENSION`，覆盖常见源码、配置、标记扩展名）把文件扩展名映射到语法高亮语言 id。它读取最后一个路径段与最后一个点之后的扩展名，大小写不敏感，并对以下情况返回 `undefined`：dotfile（`.gitignore`）、无扩展名（`/etc/hosts`）、结尾的点、以及任何未知扩展名——此时 card 省略 `lang`，UI 渲染纯文本。该表不是可调项（tunable）：它是 UI 可忽略的展示提示，而非随部署变化的选择，未知扩展名降级为纯文本而非失败。它有意保持小规模而非穷尽的语言注册表；扩展它是一行表项新增。
+
+## Alternatives considered
+
+**在 `presentResult` 中重新解析 `N: text` 面向模型文本。** 已否决：结构化行数组将不得不通过按第一个 `: ` 切分每行来重建，这既有歧义（某行文本自身含 `: `），又丢失精确的 `totalLines`（脚注只在部分分支中陈述它），并在渲染格式变化时立即失效。`presentationMeta` 携带已经结构化的数据，无需重新解析。
+
+**调用侧也打标签（`ReadCallView`），镜像终端 card 的两侧对称。** 已否决：read 调用在执行前没有内容、没有行数组、没有总数——调用侧 read card 会是一个空变体，重复 `GenericCallView`（`kind: 'read'`，跟随定位）已经表达的东西。终端 card 两侧都打标签是因为终端调用确实携带调用时数据（命令、cwd）；read 调用没有。
+
+**把结构化窗口放进新服务或旁路通道而非 `meta`。** 已否决：`meta` 是既有的持久化展示通道（write/edit 的应用 diff 就搭它），它随会话日志免费回放，无需新接线。服务会重新发明事件日志已提供的持久化与回放。
+
+**用 merge-extensible union 而非封闭标签。** 出于[渲染意图 union](../architecture/2026-07-02-tool-render-intent-union.md) 封闭的相同理由否决：新 card 需要消费代码来渲染它，因此被消费者静默丢弃的变体比编译错误更糟。把 `read` 加入封闭 union 是扩展它的许可方式——每个在 `card` 上 switch 的消费者都继续编译，因为新成员落入其 generic default，而想要富视图的消费者新增自己的分支。
+
+## Consequences
+
+`ToolResultView` 多了第四个成员。每个在 `card` 上 switch 的消费者都继续编译：TUI 和当前 Web 客户端把未知 card 路由到其 generic 路径，而 read card 携带 `content` 使该路径显示文件文本。从 `lines`/`lang`/`totalLines` 渲染带行号、语法高亮视图的 Web 前端是单独的后续 PR；本 PR 是让数据可触及的后端。在它落地前，read 在各处的渲染与之前完全一致（generic 文本 card）。
+
+read 工具现在为每次顶层 read 计算 `presentationMeta`，这是对已在手数据的一次小投影（一次 `lines.map` 和一次 `langFromPath` 调用）。meta 随会话日志持久化，因此 read 结果在磁盘上略大——它已渲染为文本的行数组，现在也以结构化形式存在。
+
+## Testing
+
+`packages/fs/tool-fs/tests/read-render.spec.ts` 单测 `langFromPath`（已知扩展名的大小写不敏感、扩展名在最后一段与最后一个点之后读取、以及 `undefined` 各情况：dotfile、无扩展名、结尾的点、未知）与 `readMetaFromMeta`（含与不含 `lang` 的良构收窄，以及每种拒绝：非对象、数组、缺失或类型错误的 `path`/`totalLines`/`lines`、畸形行项、非字符串 `lang`，以及——因为该函数收窄持久化的 opaque `meta` 边界——良构类型的回放 JSON 仍可能携带的语义无效路径：不是 1-based 整数的 `offset`、小于 `offset` 的首行 `number`、不是 1-based 整数的行 `number`（`0`、`1.5`、`NaN`、`Infinity`）、不是非负整数的 `totalLines`（`-1`、`1.5`、`NaN`）、以及行号重复、递减或超过 `totalLines` 的情况；并且收窄正 `offset` 处的空窗口（字节上限低于首个选中行））。`packages/fs/tool-fs/tests/tools.spec.ts` 固定工具接线：`execute` 把结构化窗口（含与不含 `lang` 提示）作为 `meta` 附上、`presentResult` 把它收窄为携带剥信封 `content` 的 `card: 'read'` 视图、以及各拒绝路径（错误结果、非单文本内容、meta 有效但信封畸形、信封有效但 meta 缺失或畸形）都回退到 `undefined`。两个改动的源文件保持逐文件 100% 覆盖率。本 PR 携带的是持久化 meta 与扩展后联合类型的快照证据，而非新渲染视图的证据：重录的 ACP session fixtures（`fs-read`、`fs-read-window`、`fs-edit`、`fs-policy-reject`、`fs-write-overwrite`、`parallel-tool-calls`、`workspace-context`、`workspace-edit`）钉住持久化的读取 `meta`（含 `{{cwd}}` 令牌化路径），`cordis-inspect-jsdoc` 钉住四成员的 `ToolResultView` 联合类型。已渲染读取 card 的 keyless 快照与组装应用 transcript 属于消费该视图的后续 Web PR，因为本 PR 不新增任何面向产品用户可见的渲染——TUI 通过其现有的通用 dim-Markdown 回退路由读取 card（`transcript.ts` 把 `card: 'read'` 当作 `card: 'generic'` 处理），因此其输出保持不变。`apps/cli` 的 `parallel-file-reads` 终端 golden（`apps/cli/tests/snapshots/parallel-file-reads/terminal.expected.txt`）正钉住这一点：一次真实回放执行 read 工具、经新的 `card: 'read'` 门渲染，golden 的 dim-Markdown 行与本 card 出现前 generic read 所产出的逐字节一致。
+
+## Related
+
+- [Tagged render-intent union for tool-call presentation](../architecture/2026-07-02-tool-render-intent-union.md) —— 本 Note 以 `read` 结果分支扩展的 `card` 标签词汇。
+- [Canonical tool output contract](../architecture/2026-07-20-canonical-tool-output-contract.md) —— 拥有本 Note 用来投影 read 窗口的 `presentationMeta` 持久化通道。
+- [Web terminal card](2026-07-28-web-terminal-card.md) —— 客户端消费结构化 card 的先例；read card 遵循相同的生产者模式，仅结果侧。
diff --git a/docs/config-catalog.md b/docs/config-catalog.md
index f3d855bcd5..4b9b42df34 100644
--- a/docs/config-catalog.md
+++ b/docs/config-catalog.md
@@ -1992,7 +1992,7 @@ export interface Config {
 export type ToolPresentationMode = 'native' | 'code' | 'both'
 ```
 
-Source: [`packages/core/tools/src/index.ts:582`](../packages/core/tools/src/index.ts)
+Source: [`packages/core/tools/src/index.ts:584`](../packages/core/tools/src/index.ts)
 
 ## `@deepseek-ai/dsh-tui`
 
diff --git a/docs/cordis-catalog/events.md b/docs/cordis-catalog/events.md
index 8ccc0f3d87..2496c22680 100644
--- a/docs/cordis-catalog/events.md
+++ b/docs/cordis-catalog/events.md
@@ -938,7 +938,7 @@ A tool was registered or unregistered, or a scoped restriction changed (the avai
 'tools/change'(): void
 ```
 
-Source: [`packages/core/tools/src/index.ts:160`](../../packages/core/tools/src/index.ts)
+Source: [`packages/core/tools/src/index.ts:162`](../../packages/core/tools/src/index.ts)
 
 ### `tools/code-dispatch-log` — waterfall
 
@@ -962,7 +962,7 @@ Shape the DURABLE LOG COPY of one `run_code` sub-dispatch outcome before the bri
 
 Types: [CodeDispatchLog](../core-data-structures/tools.md) · [ContentBlock](../core-data-structures/core.md) · [Scoped](../core-data-structures/scope.md) · [ToolRegistry](../core-data-structures/tools.md)
 
-Source: [`packages/core/tools/src/index.ts:142`](../../packages/core/tools/src/index.ts)
+Source: [`packages/core/tools/src/index.ts:144`](../../packages/core/tools/src/index.ts)
 
 ### `tools/execute` — waterfall
 
@@ -984,7 +984,7 @@ Around-dispatch waterfall for timeout, retry, or metrics. `next()` returns a nor
 
 Types: [Scoped](../core-data-structures/scope.md) · [ToolDispatchExecution](../core-data-structures/tools.md) · [ToolExecutionResult](../core-data-structures/tools.md) · [ToolRegistry](../core-data-structures/tools.md)
 
-Source: [`packages/core/tools/src/index.ts:117`](../../packages/core/tools/src/index.ts)
+Source: [`packages/core/tools/src/index.ts:119`](../../packages/core/tools/src/index.ts)
 
 ### `tools/post-execute` — waterfall
 
@@ -1007,7 +1007,7 @@ Accept, replace, enrich, or block a normalized dispatch result. `next()` accepts
 
 Types: [PostToolDecision](../core-data-structures/tools.md) · [Scoped](../core-data-structures/scope.md) · [ToolExecution](../core-data-structures/tools.md) · [ToolExecutionResult](../core-data-structures/tools.md) · [ToolRegistry](../core-data-structures/tools.md)
 
-Source: [`packages/core/tools/src/index.ts:129`](../../packages/core/tools/src/index.ts)
+Source: [`packages/core/tools/src/index.ts:131`](../../packages/core/tools/src/index.ts)
 
 ### `tools/pre-execute` — waterfall
 
@@ -1028,7 +1028,7 @@ Allow, deny, or ask before dispatch. `next()` delegates to allow; missing approv
 
 Types: [PreToolDecision](../core-data-structures/tools.md) · [Scoped](../core-data-structures/scope.md) · [ToolExecution](../core-data-structures/tools.md) · [ToolRegistry](../core-data-structures/tools.md)
 
-Source: [`packages/core/tools/src/index.ts:106`](../../packages/core/tools/src/index.ts)
+Source: [`packages/core/tools/src/index.ts:108`](../../packages/core/tools/src/index.ts)
 
 ### `tools/result` — emit
 
@@ -1047,7 +1047,7 @@ Observe the frozen, lossless-JSON final outcome. Listener failures are contained
 
 Types: [Scoped](../core-data-structures/scope.md) · [ToolExecution](../core-data-structures/tools.md) · [ToolExecutionResult](../core-data-structures/tools.md) · [ToolRegistry](../core-data-structures/tools.md)
 
-Source: [`packages/core/tools/src/index.ts:150`](../../packages/core/tools/src/index.ts)
+Source: [`packages/core/tools/src/index.ts:152`](../../packages/core/tools/src/index.ts)
 
 ## `workflow/*`
 
diff --git a/docs/cordis-catalog/services.md b/docs/cordis-catalog/services.md
index 40bfe8c92f..e58f91d692 100644
--- a/docs/cordis-catalog/services.md
+++ b/docs/cordis-catalog/services.md
@@ -2313,7 +2313,7 @@ async execute(exec: ToolExecutionInput): Promise<ToolExecutionResult>
 
 Types: [ScopeKey](../core-data-structures/scope.md) · [ToolDefinition](../core-data-structures/tools.md) · [ToolExecutionInput](../core-data-structures/tools.md) · [ToolExecutionMode](../core-data-structures/tools.md) · [ToolExecutionResult](../core-data-structures/tools.md) · [ToolGuard](../core-data-structures/tools.md) · [ToolRestriction](../core-data-structures/tools.md) · [ToolSchema](../core-data-structures/tools.md)
 
-Source: [`packages/core/tools/src/index.ts:704`](../../packages/core/tools/src/index.ts)
+Source: [`packages/core/tools/src/index.ts:706`](../../packages/core/tools/src/index.ts)
 
 ## `ctx.tui` — `TuiExtensionService` (abstract seam)
 
diff --git a/docs/core-data-structures/tools.i18n.yaml b/docs/core-data-structures/tools.i18n.yaml
index a6cf2bae68..e99ea06597 100644
--- a/docs/core-data-structures/tools.i18n.yaml
+++ b/docs/core-data-structures/tools.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 docs/core-data-structures/tools.md
-tools.md: 3c94f1093001e8c65365cc5baa50c1393d53b3ee
-tools.zh.md: 7a6aad81c4cfe83be8625411e4313d0c36018821
+tools.md: 62acd00a3afe50c90b2cab0bb0f170ab82852a4f
+tools.zh.md: 1ec638d6062d6496aebc019e531126343d6ead28
diff --git a/docs/core-data-structures/tools.md b/docs/core-data-structures/tools.md
index 3c94f10930..62acd00a3a 100644
--- a/docs/core-data-structures/tools.md
+++ b/docs/core-data-structures/tools.md
@@ -447,8 +447,8 @@ type ObjectJsonSchema = JsonSchemaNode & { type: 'object' }
 How a tool wants its call shown in a UI (an editor tool-call card, a CLI log line), provider-neutral so a tool describes itself without depending on any client protocol. `presentCall`/`presentResult` return a **`card`-tagged render intent** — a discriminated union a UI bridge switches on:
 
 - `ToolCallView` (pending): `{ card: 'generic', title, kind?, rawInput?, content?, locations? }` (the default card; `locations` is `{ path, line? }[]` files the call reads/modifies, for editor follow-along), `{ card: 'terminal', title, description?, cwd? }` (a shell command → a terminal card), or `{ card: 'diff', title, diffs, locations? }` (a file create/modify → an inline diff card; `diffs` is `{ path, oldText, newText }[]`, `oldText: null` for a new file).
-- `ToolResultView` (completed): `{ card: 'generic', title?, content? }`, `{ card: 'terminal', title?, output?, exitCode?, signal? }` (the captured run output + exit; a capable UI shows an exit-status pill, while another may derive a fenced ` ```console ` fallback), `{ card: 'diff', title?, diffs }` (a completed file mutation → the change to show, typically the applied hunks with context lines computed from the before/after content, or a whole-file diff when there is no before-image), or `{ card: 'web', kind: 'search' | 'fetch', title?, … }` (a completed web retrieval; `kind: 'search'` carries the structured `sources`/`answer?`/`truncated`, `kind: 'fetch'` carries `url`/`statusCode`/`truncated`, and a UI without the `web` capability falls back to the raw result content — the body is not duplicated into the view). Completed views replace pending views, so mutation tools return a diff result even when it duplicates the call-time snippet.
+- `ToolResultView` (completed): `{ card: 'generic', title?, content? }`, `{ card: 'terminal', title?, output?, exitCode?, signal? }` (the captured run output + exit; a capable UI shows an exit-status pill, while another may derive a fenced ` ```console ` fallback), `{ card: 'diff', title?, diffs }` (a completed file mutation → the change to show, typically the applied hunks with context lines computed from the before/after content, or a whole-file diff when there is no before-image), `{ card: 'read', title?, path, offset, lines, totalLines, lang?, content? }` (a completed file read → a line-numbered, optionally syntax-highlighted code view; `offset` is the 1-based first line the window requested, kept even when `lines` is empty; `lang` is a language hint from the extension, and `content` is the envelope-stripped text a UI without read support falls back to), or `{ card: 'web', kind: 'search' | 'fetch', title?, … }` (a completed web retrieval; `kind: 'search'` carries the structured `sources`/`answer?`/`truncated`, `kind: 'fetch'` carries `url`/`statusCode`/`truncated`, and a UI without the `web` capability falls back to the raw result content — the body is not duplicated into the view). Completed views replace pending views, so mutation tools return a diff result even when it duplicates the call-time snippet.
 
-`ToolCallKind` (`'read' | 'edit' | 'delete' | 'move' | 'search' | 'execute' | 'fetch' | 'other'`) picks an icon on a generic card. `FileLocation` (`{ path, line? }`) and `FileDiff` (`{ path, oldText, newText }`) are the shared file-card vocabulary. The design is pinned in [the render-intent-union Agent Note](../../.agents/notes/implemented/architecture/2026-07-02-tool-render-intent-union.md); the TUI and host/client runtime project this neutral vocabulary into their own views.
+`ToolCallKind` (`'read' | 'edit' | 'delete' | 'move' | 'search' | 'execute' | 'fetch' | 'other'`) picks an icon on a generic card. `FileLocation` (`{ path, line? }`), `FileDiff` (`{ path, oldText, newText }`), and `ReadFileLine` (`{ number, text }`, one 1-based numbered line of a read window) are the shared file-card vocabulary. The design is pinned in [the render-intent-union Agent Note](../../.agents/notes/implemented/architecture/2026-07-02-tool-render-intent-union.md); the TUI and host/client runtime project this neutral vocabulary into their own views.
 
 The full presentation field docs live in [`packages/core/tools/src/presentation.ts`](../../packages/core/tools/src/presentation.ts). The `bash` schema and executor are on [bash.md](bash.md); generic background controls are on [tasks.md](tasks.md).
diff --git a/docs/core-data-structures/tools.zh.md b/docs/core-data-structures/tools.zh.md
index 7a6aad81c4..1ec638d606 100644
--- a/docs/core-data-structures/tools.zh.md
+++ b/docs/core-data-structures/tools.zh.md
@@ -447,8 +447,8 @@ type ObjectJsonSchema = JsonSchemaNode & { type: 'object' }
 工具希望其调用在 UI 中如何呈现（编辑器工具调用卡片、CLI（命令行界面）日志行），提供方无关，使工具在不依赖任何客户端协议的情况下描述自身。`presentCall`/`presentResult` 返回一个 **`card` 标签的渲染意图**——一个可辨识联合类型，UI 桥接层据此分发：
 
 - `ToolCallView`（待执行）：`{ card: 'generic', title, kind?, rawInput?, content?, locations? }`（默认卡片；`locations` 是 `{ path, line? }[]`，表示调用读取/修改的文件，供编辑器跟随）、`{ card: 'terminal', title, description?, cwd? }`（shell 命令→终端卡片）、或 `{ card: 'diff', title, diffs, locations? }`（文件创建/修改→行内 diff 卡片；`diffs` 是 `{ path, oldText, newText }[]`，新文件时 `oldText: null`）。
-- `ToolResultView`（已完成）：`{ card: 'generic', title?, content? }`、`{ card: 'terminal', title?, output?, exitCode?, signal? }`（捕获的运行输出 + 退出状态；有能力的 UI 显示退出状态标签，其他 UI 可以派生围栏 ` ```console ` 回退）、`{ card: 'diff', title?, diffs }`（已完成的文件变更→要展示的变更，通常是从变更前后内容计算出带上下文行的已应用 hunk，或在没有前像时的整文件 diff）、或 `{ card: 'web', kind: 'search' | 'fetch', title?, … }`（已完成的 web 检索；`kind: 'search'` 携带结构化的 `sources`/`answer?`/`truncated`，`kind: 'fetch'` 携带 `url`/`statusCode`/`truncated`，不具备 `web` 能力的 UI 回退到原始结果内容——正文不会重复进视图）。已完成视图会替换待执行视图，因此变更工具即使与调用时的片段重复也要返回 diff 结果。
+- `ToolResultView`（已完成）：`{ card: 'generic', title?, content? }`、`{ card: 'terminal', title?, output?, exitCode?, signal? }`（捕获的运行输出 + 退出状态；有能力的 UI 显示退出状态标签，其他 UI 可以派生围栏 ` ```console ` 回退）、`{ card: 'diff', title?, diffs }`（已完成的文件变更→要展示的变更，通常是从变更前后内容计算出带上下文行的已应用 hunk，或在没有前像时的整文件 diff）、`{ card: 'read', title?, path, offset, lines, totalLines, lang?, content? }`（已完成的文件读取→带行号、可选语法高亮的代码视图；`offset` 是窗口请求的 1-based 起始行，即使 `lines` 为空也保留；`lang` 是从扩展名推得的语言提示，`content` 是无读取能力的 UI 回退时使用的去信封文本）、或 `{ card: 'web', kind: 'search' | 'fetch', title?, … }`（已完成的 web 检索；`kind: 'search'` 携带结构化的 `sources`/`answer?`/`truncated`，`kind: 'fetch'` 携带 `url`/`statusCode`/`truncated`，不具备 `web` 能力的 UI 回退到原始结果内容——正文不会重复进视图）。已完成视图会替换待执行视图，因此变更工具即使与调用时的片段重复也要返回 diff 结果。
 
-`ToolCallKind`（`'read' | 'edit' | 'delete' | 'move' | 'search' | 'execute' | 'fetch' | 'other'`）用于为通用卡片选择图标。`FileLocation`（`{ path, line? }`）与 `FileDiff`（`{ path, oldText, newText }`）是共享的文件卡片词汇。该设计由[渲染意图联合类型 Agent Note（agent 决策记录）](../../.agents/notes/implemented/architecture/2026-07-02-tool-render-intent-union.md)固定；TUI 和 host/client 运行时将这套中性词汇投影为各自的视图。
+`ToolCallKind`（`'read' | 'edit' | 'delete' | 'move' | 'search' | 'execute' | 'fetch' | 'other'`）用于为通用卡片选择图标。`FileLocation`（`{ path, line? }`）、`FileDiff`（`{ path, oldText, newText }`）与 `ReadFileLine`（`{ number, text }`，读取窗口中一行带 1-based 行号的内容）是共享的文件卡片词汇。该设计由[渲染意图联合类型 Agent Note（agent 决策记录）](../../.agents/notes/implemented/architecture/2026-07-02-tool-render-intent-union.md)固定；TUI 和 host/client 运行时将这套中性词汇投影为各自的视图。
 
 完整的展示字段文档见 [`packages/core/tools/src/presentation.ts`](../../packages/core/tools/src/presentation.ts)。`bash` schema 与执行器见 [bash.md](bash.md)；通用后台控制见 [tasks.md](tasks.md)。
diff --git a/docs/event-producer-consumer.md b/docs/event-producer-consumer.md
index f7c0d85c55..ec5e950ea9 100644
--- a/docs/event-producer-consumer.md
+++ b/docs/event-producer-consumer.md
@@ -48,12 +48,12 @@ This matrix shows which packages dispatch each harness-owned event and which pac
 | `system-prompt/assemble` | `waterfall` | [`packages/core/system-prompt/src/index.ts:29`](../packages/core/system-prompt/src/index.ts) | [`system-prompt`](../packages/core/system-prompt) (`waterfall`) | [`agent`](../packages/core/agent), [`system-prompt`](../packages/core/system-prompt) |
 | `system-prompt/change` | `emit` | [`packages/core/system-prompt/src/index.ts:35`](../packages/core/system-prompt/src/index.ts) | [`system-prompt`](../packages/core/system-prompt) (`emit`) | - |
 | `telemetry/record` | `waterfall` | [`packages/telemetry/session-telemetry/src/index.ts:41`](../packages/telemetry/session-telemetry/src/index.ts) | [`session-telemetry`](../packages/telemetry/session-telemetry) (`waterfall`) | - |
-| `tools/change` | `emit` | [`packages/core/tools/src/index.ts:160`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`emit`) | - |
-| `tools/code-dispatch-log` | `waterfall` | [`packages/core/tools/src/index.ts:142`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`waterfall`) | [`spill-policy`](../packages/spill/spill-policy) |
-| `tools/execute` | `waterfall` | [`packages/core/tools/src/index.ts:117`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`waterfall`) | [`session-checkpoint-policy`](../packages/session-persistence/session-checkpoint-policy), [`timeout-policy`](../packages/timeout/timeout-policy) |
-| `tools/post-execute` | `waterfall` | [`packages/core/tools/src/index.ts:129`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`waterfall`) | [`hooks-claude`](../packages/hooks/hooks-claude), [`hooks-codex`](../packages/hooks/hooks-codex), [`repeat-tool-guard`](../packages/guard/repeat-tool-guard), [`spill-policy`](../packages/spill/spill-policy), [`tool-fs-search`](../packages/fs/tool-fs-search), [`workspace-context`](../packages/context/workspace-context) |
-| `tools/pre-execute` | `waterfall` | [`packages/core/tools/src/index.ts:106`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`waterfall`) | [`hooks-claude`](../packages/hooks/hooks-claude), [`hooks-codex`](../packages/hooks/hooks-codex), [`tool-tasks`](../packages/tasks/tool-tasks) |
-| `tools/result` | `emit` | [`packages/core/tools/src/index.ts:150`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`events.dispatch`) | [`subagent-inprocess`](../packages/subagent/subagent-inprocess), [`workspace-context`](../packages/context/workspace-context) |
+| `tools/change` | `emit` | [`packages/core/tools/src/index.ts:162`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`emit`) | - |
+| `tools/code-dispatch-log` | `waterfall` | [`packages/core/tools/src/index.ts:144`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`waterfall`) | [`spill-policy`](../packages/spill/spill-policy) |
+| `tools/execute` | `waterfall` | [`packages/core/tools/src/index.ts:119`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`waterfall`) | [`session-checkpoint-policy`](../packages/session-persistence/session-checkpoint-policy), [`timeout-policy`](../packages/timeout/timeout-policy) |
+| `tools/post-execute` | `waterfall` | [`packages/core/tools/src/index.ts:131`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`waterfall`) | [`hooks-claude`](../packages/hooks/hooks-claude), [`hooks-codex`](../packages/hooks/hooks-codex), [`repeat-tool-guard`](../packages/guard/repeat-tool-guard), [`spill-policy`](../packages/spill/spill-policy), [`tool-fs-search`](../packages/fs/tool-fs-search), [`workspace-context`](../packages/context/workspace-context) |
+| `tools/pre-execute` | `waterfall` | [`packages/core/tools/src/index.ts:108`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`waterfall`) | [`hooks-claude`](../packages/hooks/hooks-claude), [`hooks-codex`](../packages/hooks/hooks-codex), [`tool-tasks`](../packages/tasks/tool-tasks) |
+| `tools/result` | `emit` | [`packages/core/tools/src/index.ts:152`](../packages/core/tools/src/index.ts) | [`tools`](../packages/core/tools) (`events.dispatch`) | [`subagent-inprocess`](../packages/subagent/subagent-inprocess), [`workspace-context`](../packages/context/workspace-context) |
 | `workflow/agent-end` | `emit` | [`packages/workflow/workflow/src/index.ts:81`](../packages/workflow/workflow/src/index.ts) | [`workflow`](../packages/workflow/workflow) (`events.dispatch`) | [`workflow`](../packages/workflow/workflow) |
 | `workflow/agent-start` | `emit` | [`packages/workflow/workflow/src/index.ts:70`](../packages/workflow/workflow/src/index.ts) | [`workflow`](../packages/workflow/workflow) (`events.dispatch`) | [`workflow`](../packages/workflow/workflow) |
 | `workflow/end` | `emit` | [`packages/workflow/workflow/src/index.ts:91`](../packages/workflow/workflow/src/index.ts) | [`workflow`](../packages/workflow/workflow) (`events.dispatch`) | [`workflow`](../packages/workflow/workflow) |
diff --git a/examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/session.jsonl b/examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/session.jsonl
index bb4798fe34..b3b8852848 100644
--- a/examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/session.jsonl
+++ b/examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/session.jsonl
@@ -11,7 +11,7 @@
 {"type":"assistant/chunk","seq":9,"time":1783951000009,"data":{"turn":1,"step":1,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}
 {"type":"assistant/message","seq":10,"time":1784449176722,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"tool-call","id":"inspect-tools-api","name":"cordis_inspect","arguments":"{\"what\":\"api\",\"name\":\"tools\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"1ac37046-d1c0-4ef6-9ea9-963e4b46d1cf"},"usage":{"inputTokens":3,"outputTokens":3}},"sourceEventSeqs":[5,6,7,8,9],"surfaceOp":"append"}
 {"type":"tool/call","seq":11,"time":1784449176722,"data":{"turn":1,"step":1,"callId":"inspect-tools-api","name":"cordis_inspect","arguments":"{\"what\":\"api\",\"name\":\"tools\"}"}}
-{"type":"tool/result","seq":12,"time":1784449176732,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"inspect-tools-api"},"content":[{"type":"tool-result","toolCallId":"inspect-tools-api","content":[{"type":"text","text":"## api\n- tools — Tool registry and execution pipeline.\n    /**\n     * Register globally or in the calling agent scope. Scoped tools shadow\n     * globals; duplicates within one layer and the reserved `run_code` name fail.\n     * @param definition - tool schema, execution, and optional finalization/presentation callbacks.\n     * @returns the exact disposer that unregisters the tool.\n     */\n    register(definition: ToolDefinition): () => void\n    /**\n     * Restrict global tools for the calling agent scope. Empty filters, unknown\n     * names, scope-local names, and reserved transport names fail. Restrictions\n     * intersect; scoped registrations remain visible.\n     * @param filter - global-surface mask: `allow` (keep only) and/or `deny` (remove).\n     * @returns the exact disposer that lifts this restriction.\n     */\n    restrict(filter: ToolRestriction): () => void\n    /**\n     * Register a monotonic guard after the extensible `tools/pre-execute`\n     * waterfall. A plain-context guard applies globally; one registered through\n     * `agent.ctx` applies only to that agent. Any matching guard may deny by\n     * returning a reason, while no guard can force-allow a call another guard\n     * denied. The exact effect disposer is returned for ordered ownership and\n     * HMR cleanup.\n     * @param guard - synchronous check; a returned string denies the execution.\n     * @returns the exact disposer that unregisters the guard.\n     */\n    guard(guard: ToolGuard): () => void\n    /**\n     * Look up a tool as one scope sees it (scoped\n     * shadows global; a restricted-away global reads as absent). Presenters pass\n     * the calling agent so the rendered card matches the definition that\n     * actually executed.\n     * @param name - the tool name as registered.\n     * @param scope - the viewing scope (the agent); omitted = the global view.\n     * @returns the definition the scope resolves, or undefined when none is visible.\n     */\n    get(name: string, scope?: ScopeKey): ToolDefinition | undefined\n    /**\n     * Project visible definitions onto the allowlisted model-facing schema fields,\n     * excluding execution and presentation callbacks.\n     * @param scope - the viewing scope (the agent); omitted = the global view.\n     * @returns one deep-cloned schema per visible tool.\n     */\n    schemas(scope?: ScopeKey): ToolSchema[]\n    /**\n     * Classify a pending call through the caller's visible tool definition. Only\n     * an exact `true` is parallel; unknown, hidden, undeclared, invalid, or\n     * throwing classifiers are exclusive.\n     * @param exec - call name, parsed arguments, and optional agent scope.\n     * @returns the fail-closed scheduling mode.\n     */\n    executionMode(exec: ToolExecutionInput): ToolExecutionMode\n    /**\n     * Execute through pre-policy, guards, around-dispatch, post-policy,\n     * definition-owned content finalization, and final notification. Tool and\n     * listener failures resolve as materialized error results; an invisible tool\n     * reports `UNKNOWN_TOOL`. The returned outcome is the same lossless, frozen\n     * snapshot final observers receive. Cancellation\n     * arriving after entry and before final result materialization skips a\n     * not-yet-started body with `ABORTED_BEFORE_DISPATCH` or replaces a\n     * successful started outcome with `ABORTED`; already-started work is still\n     * drained and may retain a tool-owned structured error.\n     * @param exec - the typed same-process call input. The registry assigns its\n     *   correlation token before policy begins.\n     * @returns the materialized final result.\n     */\n    async execute(exec: ToolExecutionInput): Promise<ToolExecutionResult>\ntype shapes (referenced by the signatures above — read these before assuming a field is a string):\n    export interface Agent {\n        readonly id: SessionId;\n        readonly options: AgentOptions;\n        readonly session: Session;\n        readonly status: AgentStatus;\n        readonly acceptsNextStep: boolean;\n        readonly ctx: Context;\n        send(message: UserMessage, options: SendOptions): void;\n        updateInbox(id: InboxItemId, action: InboxAction): InboxActionResult;\n        cancel(cause: AgentCancelCause, options?: CancelOptions): void;\n        whenIdle(): Promise<void>;\n        followup(message: UserMessage): void;\n        steer(message: UserMessage): void;\n        inject(message: UserMessage): void;\n    }\n    export type AgentCancelCause = {\n        readonly kind: 'user';\n    } | {\n        readonly kind: 'parent';\n    };\n    export interface AgentOptions {\n        provider?: string;\n        model?: string;\n        maxTokens?: number;\n    }\n    export type AgentStatus = 'idle' | 'running';\n    export interface AssistantMessage extends Message {\n        readonly role: 'assistant';\n        readonly source: ModelMessageSource;\n    }\n    export interface AssistantProvenance {\n        provider: string;\n        model: string;\n        replayState?: unknown;\n    }\n    export type Branded<B extends string> = string & {\n        readonly [BRAND]: B;\n    };\n    export type CallId = Branded<'CallId'>;\n    export interface CancelOptions {\n        keepInbox?: boolean;\n    }\n    export interface ContentBlockMap {\n        'text': TextBlock;\n        'reasoning': ReasoningBlock;\n        'tool-call': ToolCallBlock;\n        'tool-result': ToolResultBlock;\n    }\n    export type ContentBlockType = keyof ContentBlockMap;\n    export interface DiffCallView {\n        card: 'diff';\n        title: string;\n        diffs: FileDiff[];\n        locations?: FileLocation[];\n    }\n    export interface DiffResultView {\n        card: 'diff';\n        title?: string;\n        diffs: FileDiff[];\n    }\n    export interface EpochHeader {\n        config: LlmCallConfig;\n        adapterDefaults?: LlmCallConfigAdapterDefaults;\n        system?: string;\n        tools?: ToolSchema[];\n    }\n    export interface FileDiff {\n        path: string;\n        oldText: string | null;\n        newText: string;\n    }\n    export interface FileLocation {\n        path: string;\n        line?: number;\n    }\n    export type FinishReason = FinishReasonMap[keyof FinishReasonMap];\n    export interface FinishReasonMap {\n        'stop': {\n            kind: 'stop';\n        };\n        'tool-calls': {\n            kind: 'tool-calls';\n        };\n        'max-tokens': {\n            kind: 'max-tokens';\n        };\n        'aborted': {\n            kind: 'aborted';\n            failure: LlmFailure;\n        };\n        'error': {\n            kind: 'error';\n            failure: LlmFailure;\n        };\n    }\n    export interface GenericCallView {\n        card: 'generic';\n        title: string;\n        kind?: ToolCallKind;\n        rawInput?: unknown;\n        content?: ContentBlock[];\n        locations?: FileLocation[];\n    }\n    export interface GenericResultView {\n        card: 'generic';\n        title?: string;\n        content?: ContentBlock[];\n    }\n    export type InboxAction = {\n        readonly kind: 'edit';\n        readonly content: ContentBlock[];\n    } | {\n        readonly kind: 'remove';\n    };\n    export type InboxActionResult = 'applied' | 'not-found';\n    export type InboxItemId = Branded<'InboxItemId'>;\n    export interface JsonSchemaNode {\n        type?: JsonSchemaType;\n        oneOf?: JsonSchemaNode[];\n        properties?: Record<string, JsonSchemaNode>;\n        required?: string[];\n        additionalProperties?: boolean;\n        items?: JsonSchemaNode;\n        enum?: JsonSchemaScalar[];\n        const?: JsonSchemaScalar;\n        description?: string;\n        title?: string;\n        default?: JsonValue;\n        examples?: JsonValue;\n    }\n    export type JsonSchemaScalar = string | number | boolean | null;\n    export type JsonSchemaType = 'object' | 'array' | 'string' | 'number' | 'integer' | 'boolean' | 'null';\n    export type JsonValue = null | boolean | number | string | JsonValue[] | {\n        [key: string]: JsonValue;\n    };\n    export interface LlmCallConfig {\n        provider: string;\n        model: string;\n        reasoningEffort?: ReasoningEffortId;\n        temperature?: number;\n        maxTokens?: number;\n        stop?: string[];\n    }\n    export interface LlmCallConfigAdapterDefaults {\n        reasoningEffort?: true;\n        maxTokens?: true;\n    }\n    export interface LlmFailure {\n        readonly message: string;\n        readonly code: string;\n        readonly status?: number;\n        readonly providerRetryAfterMs?: number;\n        readonly requestId?: ProviderRequestId;\n    }\n    export interface Message {\n        readonly id: MessageId;\n        readonly role: 'system' | 'user' | 'assistant';\n        readonly content: ContentBlock[];\n        readonly source: MessageSource;\n    }\n    export type MessageId = Branded<'MessageId'>;\n    export type MessageSource = MessageSourceMap[keyof MessageSourceMap];\n    export interface MessageSourceMap {\n        user: {\n            kind: 'user';\n        };\n        plugin: {\n            kind: 'plugin';\n            plugin: string;\n        };\n        model: ModelMessageSource;\n        tool: ToolMessageSource;\n    }\n    export interface ModelMessageSource extends AssistantProvenance {\n        kind: 'model';\n    }\n    export type ProviderRequestId = Branded<'ProviderRequestId'>;\n    export interface ReasoningBlock {\n        type: 'reasoning';\n        text: string;\n    }\n    export type ReasoningEffortId = Branded<'ReasoningEffortId'>;\n    export type RequestHeaderReason = 'initial' | 'resume' | 'change';\n    export type ScopeKey = object;\n    export interface SendOptions {\n        target: SendTarget;\n        wakeup: boolean;\n    }\n    export type SendTarget = 'next-turn' | 'next-step';\n    export class Session {\n        get surface(): SessionSurface;\n        readonly header: SessionHeader;\n        get id(): SessionId;\n        readonly firstLiveSeq: number;\n        constructor(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader);\n        get events(): readonly SessionEvent[];\n        get seq(): number;\n        append<T extends SessionEventType>(type: T, data: SessionEventMap[T], ...opts: T extends SurfaceEventType ? [\n            opts: SurfaceIntent\n        ] : [\n        ]): SessionEvent<T>;\n        requestHeader(): EpochHeader | undefined;\n        deriveMessages(): Message[];\n        deriveEventMessage(event: SessionEvent): Message | null;\n    }\n    export type SessionEvent<T extends SessionEventType = SessionEventType> = {\n        [K in SessionEventType]: {\n            type: K;\n            seq: number;\n            time: number;\n            data: SessionEventMap[K];\n        } & (K extends SurfaceEventType ? {\n            sourceEventSeqs?: number[];\n            surfaceOp?: SurfaceOp;\n        } : object);\n    }[T];\n    export interface SessionEventMap {\n        'turn/start': {\n            turn: number;\n            trigger: TurnTrigger;\n        };\n        'turn/end': {\n            turn: number;\n            reason: TurnEndReason;\n        };\n        'step/start': {\n            turn: number;\n            step: number;\n        };\n        'step/end': {\n            turn: number;\n            step: number;\n        };\n        'user/message': UserMessage;\n        'assistant/chunk': {\n            turn: number;\n            step: number;\n            chunk: StreamChunk;\n        };\n        'assistant/message': {\n            turn: number;\n            step: number;\n            message: AssistantMessage;\n            usage?: TokenUsage;\n        };\n        'tool/call': {\n            turn: number;\n            step: number;\n            callId: CallId;\n            name: string;\n            arguments: string;\n        };\n        'tool/result': {\n            turn: number;\n            step: number;\n            message: ToolResultMessage;\n            error?: {\n                name: string;\n                code: string;\n            };\n            meta?: JsonValue;\n        };\n        'steering/message': {\n            turn: number;\n            message: UserMessage;\n        };\n        'todo/write': {\n            todos: TodoItem[];\n        };\n        'request/header': {\n            header: EpochHeader;\n            reason: RequestHeaderReason;\n        };\n        'session/end-seed': Record<string, never>;\n    }\n    export type SessionEventType = keyof SessionEventMap;\n    export interface SessionHeader {\n        readonly version: number;\n        readonly id: SessionId;\n        readonly createdAt: number;\n        readonly cwd?: string;\n        readonly parentSession?: SessionId;\n        readonly seedLength?: number;\n        readonly delegationDepth?: number;\n    }\n    export type SessionId = Branded<'SessionId'>;\n    export interface SessionSurface {\n        readonly nodes: readonly number[];\n        readonly replaceGeneration: number;\n    }\n    export type StreamChunk = {\n        type: 'block-start';\n        index: number;\n        blockType: ContentBlockType;\n    } | {\n        type: 'text-delta';\n        index: number;\n        text: string;\n    } | {\n        type: 'reasoning-delta';\n        index: number;\n        text: string;\n    } | {\n        type: 'tool-call-delta';\n        index: number;\n        id: CallId;\n        name?: string;\n        argumentsDelta: string;\n    } | {\n        type: 'block-end';\n        index: number;\n        block: ContentBlock;\n    } | {\n        type: 'usage';\n        usage: TokenUsage;\n    } | {\n        type: 'finish';\n        reason: FinishReason;\n        replayState?: unknown;\n    };\n    export type SurfaceEventType = 'user/message' | 'assistant/message' | 'tool/result' | 'steering/message';\n    export interface SurfaceIntent {\n        surfaceOp: SurfaceOp;\n        sourceEventSeqs?: number[];\n    }\n    export type SurfaceOp = 'append' | {\n        op: 'replace';\n        start: number;\n        end: number;\n    };\n    export interface TerminalCallView {\n        card: 'terminal';\n        title: string;\n        description?: string;\n        cwd?: string;\n    }\n    export interface TerminalResultView {\n        card: 'terminal';\n        title?: string;\n        output?: string;\n        exitCode?: number;\n        signal?: string;\n    }\n    export interface TodoItem {\n        content: string;\n        status: 'pending' | 'in_progress' | 'completed';\n    }\n    export interface TokenUsage {\n        inputTokens: number;\n        outputTokens: number;\n        cacheReadTokens?: number;\n        cacheWriteTokens?: number;\n        reasoningTokens?: number;\n    }\n    export interface ToolCallBlock {\n        type: 'tool-call';\n        id: CallId;\n        name: string;\n        arguments: string;\n    }\n    export type ToolCallKind = 'read' | 'edit' | 'delete' | 'move' | 'search' | 'execute' | 'fetch' | 'other';\n    export type ToolCallView = GenericCallView | TerminalCallView | DiffCallView;\n    export interface ToolDefinition extends ToolSchema {\n        readonly output: ToolOutputDefinition;\n        execute(args: unknown, exec: ToolRunContext): Promise<unknown>;\n        finalizeContent?(exec: Readonly<ToolExecution>, result: Readonly<ToolExecutionResult>): ContentBlock[] | undefined;\n        timeoutMs?: number;\n        isConcurrencySafe?(args: unknown): boolean;\n        presentCall?(args: unknown): ToolCallView | undefined;\n        presentResult?(args: unknown, result: ToolResult): ToolResultView | undefined;\n    }\n    export interface ToolErrorInfo {\n        name: string;\n        code: string;\n    }\n    export interface ToolExecution extends ToolExecutionInput {\n        readonly token: ToolExecutionToken;\n    }\n    export interface ToolExecutionFailure {\n        readonly isError: true;\n        readonly error: ToolFailure;\n        readonly value?: never;\n        readonly content: ContentBlock[];\n        readonly meta?: JsonValue;\n        readonly additionalContexts?: UserMessage[];\n        readonly concludesTurn?: never;\n    }\n    export interface ToolExecutionInput {\n        readonly callId: CallId;\n        readonly name: string;\n        readonly arguments: unknown;\n        readonly agent?: Agent;\n        readonly parent?: ToolExecutionToken;\n        readonly signal: AbortSignal;\n    }\n    export type ToolExecutionMode = {\n        kind: 'parallel';\n    } | {\n        kind: 'exclusive';\n    };\n    export type ToolExecutionResult = ToolExecutionSuccess | ToolExecutionFailure;\n    export interface ToolExecutionSuccess {\n        readonly isError: false;\n        readonly value: JsonValue;\n        readonly content: ContentBlock[];\n        readonly error?: never;\n        readonly meta?: JsonValue;\n        readonly additionalContexts?: UserMessage[];\n        readonly concludesTurn?: true;\n    }\n    export type ToolExecutionToken = symbol & {\n        readonly [toolExecutionTokenBrand]: true;\n    };\n    export interface ToolFailure {\n        message: string;\n        info?: ToolErrorInfo;\n    }\n    export type ToolGuard = (execution: Readonly<ToolExecution>) => string | undefined;\n    export interface ToolMessageSource {\n        kind: 'tool';\n        callId: CallId;\n    }\n    export interface ToolOutputDefinition {\n        readonly schema: JsonSchemaNode;\n        render(args: unknown, value: JsonValue): ContentBlock[];\n        presentationMeta?(args: unknown, value: JsonValue): JsonValue;\n    }\n    export interface ToolRestriction {\n        readonly allow?: readonly string[];\n        readonly deny?: readonly string[];\n    }\n    export interface ToolResult {\n        content: ContentBlock[];\n        isError: boolean;\n        meta?: JsonValue;\n    }\n    export interface ToolResultBlock {\n        type: 'tool-result';\n        toolCallId: CallId;\n        content: ContentBlock[];\n        isError?: boolean;\n    }\n    export interface ToolResultMessage extends Message {\n        readonly role: 'user';\n        readonly content: [\n            ToolResultBlock\n        ];\n        readonly source: ToolMessageSource;\n    }\n    export type ToolResultView = GenericResultView | TerminalResultView | DiffResultView | WebResultView;\n    export interface ToolRunContext extends ToolExecution {\n        deferContext(context: UserMessage): void;\n        concludeTurn(): void;\n    }\n    export interface ToolSchema {\n        name: string;\n        description: string;\n        parameters: Record<string, unknown>;\n    }\n    export type TurnEndReason = TurnEndReasonMap[keyof TurnEndReasonMap];\n    export interface TurnEndReasonMap {\n        completed: {\n            kind: 'completed';\n        };\n        aborted: {\n            kind: 'aborted';\n        };\n        error: {\n            kind: 'error';\n            step: number;\n        } & ({\n            failure: LlmFailure;\n            message?: never;\n            code?: never;\n        } | {\n            message: string;\n            code?: string;\n            failure?: never;\n        });\n        disposed: {\n            kind: 'disposed';\n        };\n        'max-tokens': {\n            kind: 'max-tokens';\n        };\n        interrupted: {\n            kind: 'interrupted';\n        };\n    }\n    export type TurnTrigger = TurnTriggerMap[keyof TurnTriggerMap];\n    export interface TurnTriggerMap {\n        message: {\n            kind: 'message';\n            source: MessageSource;\n        };\n        retry: {\n            kind: 'retry';\n        };\n        injection: {\n            kind: 'injection';\n            source: MessageSource;\n        };\n    }\n    export interface UserMessage extends Message {\n        readonly role: 'user';\n    }\n    export interface WebFetchResultView {\n        card: 'web';\n        kind: 'fetch';\n        title?: string;\n        url: string;\n        statusCode: number;\n        truncated: boolean;\n    }\n    export type WebResultView = WebSearchResultView | WebFetchResultView;\n    export interface WebSearchResultView {\n        card: 'web';\n        kind: 'search';\n        title?: string;\n        sources: WebSource[];\n        answer?: string;\n        truncated: boolean;\n    }\n    export interface WebSource {\n        url: string;\n        title?: string;\n        snippet?: string;\n        publishedAt?: string;\n    }"}],"isError":false}],"role":"user","id":"1c43b8df-aae8-42e7-8253-5b275edc09bc"}},"sourceEventSeqs":[11],"surfaceOp":"append"}
+{"type":"tool/result","seq":12,"time":1784449176732,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"inspect-tools-api"},"content":[{"type":"tool-result","toolCallId":"inspect-tools-api","content":[{"type":"text","text":"## api\n- tools — Tool registry and execution pipeline.\n    /**\n     * Register globally or in the calling agent scope. Scoped tools shadow\n     * globals; duplicates within one layer and the reserved `run_code` name fail.\n     * @param definition - tool schema, execution, and optional finalization/presentation callbacks.\n     * @returns the exact disposer that unregisters the tool.\n     */\n    register(definition: ToolDefinition): () => void\n    /**\n     * Restrict global tools for the calling agent scope. Empty filters, unknown\n     * names, scope-local names, and reserved transport names fail. Restrictions\n     * intersect; scoped registrations remain visible.\n     * @param filter - global-surface mask: `allow` (keep only) and/or `deny` (remove).\n     * @returns the exact disposer that lifts this restriction.\n     */\n    restrict(filter: ToolRestriction): () => void\n    /**\n     * Register a monotonic guard after the extensible `tools/pre-execute`\n     * waterfall. A plain-context guard applies globally; one registered through\n     * `agent.ctx` applies only to that agent. Any matching guard may deny by\n     * returning a reason, while no guard can force-allow a call another guard\n     * denied. The exact effect disposer is returned for ordered ownership and\n     * HMR cleanup.\n     * @param guard - synchronous check; a returned string denies the execution.\n     * @returns the exact disposer that unregisters the guard.\n     */\n    guard(guard: ToolGuard): () => void\n    /**\n     * Look up a tool as one scope sees it (scoped\n     * shadows global; a restricted-away global reads as absent). Presenters pass\n     * the calling agent so the rendered card matches the definition that\n     * actually executed.\n     * @param name - the tool name as registered.\n     * @param scope - the viewing scope (the agent); omitted = the global view.\n     * @returns the definition the scope resolves, or undefined when none is visible.\n     */\n    get(name: string, scope?: ScopeKey): ToolDefinition | undefined\n    /**\n     * Project visible definitions onto the allowlisted model-facing schema fields,\n     * excluding execution and presentation callbacks.\n     * @param scope - the viewing scope (the agent); omitted = the global view.\n     * @returns one deep-cloned schema per visible tool.\n     */\n    schemas(scope?: ScopeKey): ToolSchema[]\n    /**\n     * Classify a pending call through the caller's visible tool definition. Only\n     * an exact `true` is parallel; unknown, hidden, undeclared, invalid, or\n     * throwing classifiers are exclusive.\n     * @param exec - call name, parsed arguments, and optional agent scope.\n     * @returns the fail-closed scheduling mode.\n     */\n    executionMode(exec: ToolExecutionInput): ToolExecutionMode\n    /**\n     * Execute through pre-policy, guards, around-dispatch, post-policy,\n     * definition-owned content finalization, and final notification. Tool and\n     * listener failures resolve as materialized error results; an invisible tool\n     * reports `UNKNOWN_TOOL`. The returned outcome is the same lossless, frozen\n     * snapshot final observers receive. Cancellation\n     * arriving after entry and before final result materialization skips a\n     * not-yet-started body with `ABORTED_BEFORE_DISPATCH` or replaces a\n     * successful started outcome with `ABORTED`; already-started work is still\n     * drained and may retain a tool-owned structured error.\n     * @param exec - the typed same-process call input. The registry assigns its\n     *   correlation token before policy begins.\n     * @returns the materialized final result.\n     */\n    async execute(exec: ToolExecutionInput): Promise<ToolExecutionResult>\ntype shapes (referenced by the signatures above — read these before assuming a field is a string):\n    export interface Agent {\n        readonly id: SessionId;\n        readonly options: AgentOptions;\n        readonly session: Session;\n        readonly status: AgentStatus;\n        readonly acceptsNextStep: boolean;\n        readonly ctx: Context;\n        send(message: UserMessage, options: SendOptions): void;\n        updateInbox(id: InboxItemId, action: InboxAction): InboxActionResult;\n        cancel(cause: AgentCancelCause, options?: CancelOptions): void;\n        whenIdle(): Promise<void>;\n        followup(message: UserMessage): void;\n        steer(message: UserMessage): void;\n        inject(message: UserMessage): void;\n    }\n    export type AgentCancelCause = {\n        readonly kind: 'user';\n    } | {\n        readonly kind: 'parent';\n    };\n    export interface AgentOptions {\n        provider?: string;\n        model?: string;\n        maxTokens?: number;\n    }\n    export type AgentStatus = 'idle' | 'running';\n    export interface AssistantMessage extends Message {\n        readonly role: 'assistant';\n        readonly source: ModelMessageSource;\n    }\n    export interface AssistantProvenance {\n        provider: string;\n        model: string;\n        replayState?: unknown;\n    }\n    export type Branded<B extends string> = string & {\n        readonly [BRAND]: B;\n    };\n    export type CallId = Branded<'CallId'>;\n    export interface CancelOptions {\n        keepInbox?: boolean;\n    }\n    export interface ContentBlockMap {\n        'text': TextBlock;\n        'reasoning': ReasoningBlock;\n        'tool-call': ToolCallBlock;\n        'tool-result': ToolResultBlock;\n    }\n    export type ContentBlockType = keyof ContentBlockMap;\n    export interface DiffCallView {\n        card: 'diff';\n        title: string;\n        diffs: FileDiff[];\n        locations?: FileLocation[];\n    }\n    export interface DiffResultView {\n        card: 'diff';\n        title?: string;\n        diffs: FileDiff[];\n    }\n    export interface EpochHeader {\n        config: LlmCallConfig;\n        adapterDefaults?: LlmCallConfigAdapterDefaults;\n        system?: string;\n        tools?: ToolSchema[];\n    }\n    export interface FileDiff {\n        path: string;\n        oldText: string | null;\n        newText: string;\n    }\n    export interface FileLocation {\n        path: string;\n        line?: number;\n    }\n    export type FinishReason = FinishReasonMap[keyof FinishReasonMap];\n    export interface FinishReasonMap {\n        'stop': {\n            kind: 'stop';\n        };\n        'tool-calls': {\n            kind: 'tool-calls';\n        };\n        'max-tokens': {\n            kind: 'max-tokens';\n        };\n        'aborted': {\n            kind: 'aborted';\n            failure: LlmFailure;\n        };\n        'error': {\n            kind: 'error';\n            failure: LlmFailure;\n        };\n    }\n    export interface GenericCallView {\n        card: 'generic';\n        title: string;\n        kind?: ToolCallKind;\n        rawInput?: unknown;\n        content?: ContentBlock[];\n        locations?: FileLocation[];\n    }\n    export interface GenericResultView {\n        card: 'generic';\n        title?: string;\n        content?: ContentBlock[];\n    }\n    export type InboxAction = {\n        readonly kind: 'edit';\n        readonly content: ContentBlock[];\n    } | {\n        readonly kind: 'remove';\n    };\n    export type InboxActionResult = 'applied' | 'not-found';\n    export type InboxItemId = Branded<'InboxItemId'>;\n    export interface JsonSchemaNode {\n        type?: JsonSchemaType;\n        oneOf?: JsonSchemaNode[];\n        properties?: Record<string, JsonSchemaNode>;\n        required?: string[];\n        additionalProperties?: boolean;\n        items?: JsonSchemaNode;\n        enum?: JsonSchemaScalar[];\n        const?: JsonSchemaScalar;\n        description?: string;\n        title?: string;\n        default?: JsonValue;\n        examples?: JsonValue;\n    }\n    export type JsonSchemaScalar = string | number | boolean | null;\n    export type JsonSchemaType = 'object' | 'array' | 'string' | 'number' | 'integer' | 'boolean' | 'null';\n    export type JsonValue = null | boolean | number | string | JsonValue[] | {\n        [key: string]: JsonValue;\n    };\n    export interface LlmCallConfig {\n        provider: string;\n        model: string;\n        reasoningEffort?: ReasoningEffortId;\n        temperature?: number;\n        maxTokens?: number;\n        stop?: string[];\n    }\n    export interface LlmCallConfigAdapterDefaults {\n        reasoningEffort?: true;\n        maxTokens?: true;\n    }\n    export interface LlmFailure {\n        readonly message: string;\n        readonly code: string;\n        readonly status?: number;\n        readonly providerRetryAfterMs?: number;\n        readonly requestId?: ProviderRequestId;\n    }\n    export interface Message {\n        readonly id: MessageId;\n        readonly role: 'system' | 'user' | 'assistant';\n        readonly content: ContentBlock[];\n        readonly source: MessageSource;\n    }\n    export type MessageId = Branded<'MessageId'>;\n    export type MessageSource = MessageSourceMap[keyof MessageSourceMap];\n    export interface MessageSourceMap {\n        user: {\n            kind: 'user';\n        };\n        plugin: {\n            kind: 'plugin';\n            plugin: string;\n        };\n        model: ModelMessageSource;\n        tool: ToolMessageSource;\n    }\n    export interface ModelMessageSource extends AssistantProvenance {\n        kind: 'model';\n    }\n    export type ProviderRequestId = Branded<'ProviderRequestId'>;\n    export interface ReadFileLine {\n        number: number;\n        text: string;\n    }\n    export interface ReadResultView {\n        card: 'read';\n        title?: string;\n        path: string;\n        offset: number;\n        lines: ReadFileLine[];\n        totalLines: number;\n        lang?: string;\n        content?: ContentBlock[];\n    }\n    export interface ReasoningBlock {\n        type: 'reasoning';\n        text: string;\n    }\n    export type ReasoningEffortId = Branded<'ReasoningEffortId'>;\n    export type RequestHeaderReason = 'initial' | 'resume' | 'change';\n    export type ScopeKey = object;\n    export interface SendOptions {\n        target: SendTarget;\n        wakeup: boolean;\n    }\n    export type SendTarget = 'next-turn' | 'next-step';\n    export class Session {\n        get surface(): SessionSurface;\n        readonly header: SessionHeader;\n        get id(): SessionId;\n        readonly firstLiveSeq: number;\n        constructor(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader);\n        get events(): readonly SessionEvent[];\n        get seq(): number;\n        append<T extends SessionEventType>(type: T, data: SessionEventMap[T], ...opts: T extends SurfaceEventType ? [\n            opts: SurfaceIntent\n        ] : [\n        ]): SessionEvent<T>;\n        requestHeader(): EpochHeader | undefined;\n        deriveMessages(): Message[];\n        deriveEventMessage(event: SessionEvent): Message | null;\n    }\n    export type SessionEvent<T extends SessionEventType = SessionEventType> = {\n        [K in SessionEventType]: {\n            type: K;\n            seq: number;\n            time: number;\n            data: SessionEventMap[K];\n        } & (K extends SurfaceEventType ? {\n            sourceEventSeqs?: number[];\n            surfaceOp?: SurfaceOp;\n        } : object);\n    }[T];\n    export interface SessionEventMap {\n        'turn/start': {\n            turn: number;\n            trigger: TurnTrigger;\n        };\n        'turn/end': {\n            turn: number;\n            reason: TurnEndReason;\n        };\n        'step/start': {\n            turn: number;\n            step: number;\n        };\n        'step/end': {\n            turn: number;\n            step: number;\n        };\n        'user/message': UserMessage;\n        'assistant/chunk': {\n            turn: number;\n            step: number;\n            chunk: StreamChunk;\n        };\n        'assistant/message': {\n            turn: number;\n            step: number;\n            message: AssistantMessage;\n            usage?: TokenUsage;\n        };\n        'tool/call': {\n            turn: number;\n            step: number;\n            callId: CallId;\n            name: string;\n            arguments: string;\n        };\n        'tool/result': {\n            turn: number;\n            step: number;\n            message: ToolResultMessage;\n            error?: {\n                name: string;\n                code: string;\n            };\n            meta?: JsonValue;\n        };\n        'steering/message': {\n            turn: number;\n            message: UserMessage;\n        };\n        'todo/write': {\n            todos: TodoItem[];\n        };\n        'request/header': {\n            header: EpochHeader;\n            reason: RequestHeaderReason;\n        };\n        'session/end-seed': Record<string, never>;\n    }\n    export type SessionEventType = keyof SessionEventMap;\n    export interface SessionHeader {\n        readonly version: number;\n        readonly id: SessionId;\n        readonly createdAt: number;\n        readonly cwd?: string;\n        readonly parentSession?: SessionId;\n        readonly seedLength?: number;\n        readonly delegationDepth?: number;\n    }\n    export type SessionId = Branded<'SessionId'>;\n    export interface SessionSurface {\n        readonly nodes: readonly number[];\n        readonly replaceGeneration: number;\n    }\n    export type StreamChunk = {\n        type: 'block-start';\n        index: number;\n        blockType: ContentBlockType;\n    } | {\n        type: 'text-delta';\n        index: number;\n        text: string;\n    } | {\n        type: 'reasoning-delta';\n        index: number;\n        text: string;\n    } | {\n        type: 'tool-call-delta';\n        index: number;\n        id: CallId;\n        name?: string;\n        argumentsDelta: string;\n    } | {\n        type: 'block-end';\n        index: number;\n        block: ContentBlock;\n    } | {\n        type: 'usage';\n        usage: TokenUsage;\n    } | {\n        type: 'finish';\n        reason: FinishReason;\n        replayState?: unknown;\n    };\n    export type SurfaceEventType = 'user/message' | 'assistant/message' | 'tool/result' | 'steering/message';\n    export interface SurfaceIntent {\n        surfaceOp: SurfaceOp;\n        sourceEventSeqs?: number[];\n    }\n    export type SurfaceOp = 'append' | {\n        op: 'replace';\n        start: number;\n        end: number;\n    };\n    export interface TerminalCallView {\n        card: 'terminal';\n        title: string;\n        description?: string;\n        cwd?: string;\n    }\n    export interface TerminalResultView {\n        card: 'terminal';\n        title?: string;\n        output?: string;\n        exitCode?: number;\n        signal?: string;\n    }\n    export interface TodoItem {\n        content: string;\n        status: 'pending' | 'in_progress' | 'completed';\n    }\n    export interface TokenUsage {\n        inputTokens: number;\n        outputTokens: number;\n        cacheReadTokens?: number;\n        cacheWriteTokens?: number;\n        reasoningTokens?: number;\n    }\n    export interface ToolCallBlock {\n        type: 'tool-call';\n        id: CallId;\n        name: string;\n        arguments: string;\n    }\n    export type ToolCallKind = 'read' | 'edit' | 'delete' | 'move' | 'search' | 'execute' | 'fetch' | 'other';\n    export type ToolCallView = GenericCallView | TerminalCallView | DiffCallView;\n    export interface ToolDefinition extends ToolSchema {\n        readonly output: ToolOutputDefinition;\n        execute(args: unknown, exec: ToolRunContext): Promise<unknown>;\n        finalizeContent?(exec: Readonly<ToolExecution>, result: Readonly<ToolExecutionResult>): ContentBlock[] | undefined;\n        timeoutMs?: number;\n        isConcurrencySafe?(args: unknown): boolean;\n        presentCall?(args: unknown): ToolCallView | undefined;\n        presentResult?(args: unknown, result: ToolResult): ToolResultView | undefined;\n    }\n    export interface ToolErrorInfo {\n        name: string;\n        code: string;\n    }\n    export interface ToolExecution extends ToolExecutionInput {\n        readonly token: ToolExecutionToken;\n    }\n    export interface ToolExecutionFailure {\n        readonly isError: true;\n        readonly error: ToolFailure;\n        readonly value?: never;\n        readonly content: ContentBlock[];\n        readonly meta?: JsonValue;\n        readonly additionalContexts?: UserMessage[];\n        readonly concludesTurn?: never;\n    }\n    export interface ToolExecutionInput {\n        readonly callId: CallId;\n        readonly name: string;\n        readonly arguments: unknown;\n        readonly agent?: Agent;\n        readonly parent?: ToolExecutionToken;\n        readonly signal: AbortSignal;\n    }\n    export type ToolExecutionMode = {\n        kind: 'parallel';\n    } | {\n        kind: 'exclusive';\n    };\n    export type ToolExecutionResult = ToolExecutionSuccess | ToolExecutionFailure;\n    export interface ToolExecutionSuccess {\n        readonly isError: false;\n        readonly value: JsonValue;\n        readonly content: ContentBlock[];\n        readonly error?: never;\n        readonly meta?: JsonValue;\n        readonly additionalContexts?: UserMessage[];\n        readonly concludesTurn?: true;\n    }\n    export type ToolExecutionToken = symbol & {\n        readonly [toolExecutionTokenBrand]: true;\n    };\n    export interface ToolFailure {\n        message: string;\n        info?: ToolErrorInfo;\n    }\n    export type ToolGuard = (execution: Readonly<ToolExecution>) => string | undefined;\n    export interface ToolMessageSource {\n        kind: 'tool';\n        callId: CallId;\n    }\n    export interface ToolOutputDefinition {\n        readonly schema: JsonSchemaNode;\n        render(args: unknown, value: JsonValue): ContentBlock[];\n        presentationMeta?(args: unknown, value: JsonValue): JsonValue;\n    }\n    export interface ToolRestriction {\n        readonly allow?: readonly string[];\n        readonly deny?: readonly string[];\n    }\n    export interface ToolResult {\n        content: ContentBlock[];\n        isError: boolean;\n        meta?: JsonValue;\n    }\n    export interface ToolResultBlock {\n        type: 'tool-result';\n        toolCallId: CallId;\n        content: ContentBlock[];\n        isError?: boolean;\n    }\n    export interface ToolResultMessage extends Message {\n        readonly role: 'user';\n        readonly content: [\n            ToolResultBlock\n        ];\n        readonly source: ToolMessageSource;\n    }\n    export type ToolResultView = GenericResultView | TerminalResultView | DiffResultView | ReadResultView | WebResultView;\n    export interface ToolRunContext extends ToolExecution {\n        deferContext(context: UserMessage): void;\n        concludeTurn(): void;\n    }\n    export interface ToolSchema {\n        name: string;\n        description: string;\n        parameters: Record<string, unknown>;\n    }\n    export type TurnEndReason = TurnEndReasonMap[keyof TurnEndReasonMap];\n    export interface TurnEndReasonMap {\n        completed: {\n            kind: 'completed';\n        };\n        aborted: {\n            kind: 'aborted';\n        };\n        error: {\n            kind: 'error';\n            step: number;\n        } & ({\n            failure: LlmFailure;\n            message?: never;\n            code?: never;\n        } | {\n            message: string;\n            code?: string;\n            failure?: never;\n        });\n        disposed: {\n            kind: 'disposed';\n        };\n        'max-tokens': {\n            kind: 'max-tokens';\n        };\n        interrupted: {\n            kind: 'interrupted';\n        };\n    }\n    export type TurnTrigger = TurnTriggerMap[keyof TurnTriggerMap];\n    export interface TurnTriggerMap {\n        message: {\n            kind: 'message';\n            source: MessageSource;\n        };\n        retry: {\n            kind: 'retry';\n        };\n        injection: {\n            kind: 'injection';\n            source: MessageSource;\n        };\n    }\n    export interface UserMessage extends Message {\n        readonly role: 'user';\n    }\n    export interface WebFetchResultView {\n        card: 'web';\n        kind: 'fetch';\n        title?: string;\n        url: string;\n        statusCode: number;\n        truncated: boolean;\n    }\n    export type WebResultView = WebSearchResultView | WebFetchResultView;\n    export interface WebSearchResultView {\n        card: 'web';\n        kind: 'search';\n        title?: string;\n        sources: WebSource[];\n        answer?: string;\n        truncated: boolean;\n    }\n    export interface WebSource {\n        url: string;\n        title?: string;\n        snippet?: string;\n        publishedAt?: string;\n    }"}],"isError":false}],"role":"user","id":"1c43b8df-aae8-42e7-8253-5b275edc09bc"}},"sourceEventSeqs":[11],"surfaceOp":"append"}
 {"type":"step/end","seq":13,"time":1784449176732,"data":{"turn":1,"step":1}}
 {"type":"step/start","seq":14,"time":1784449176733,"data":{"turn":1,"step":2}}
 {"type":"assistant/chunk","seq":15,"time":1783951000015,"data":{"turn":1,"step":2,"chunk":{"type":"block-start","index":0,"blockType":"tool-call"}}}
diff --git a/examples/acp-agent/tests/snapshots/fs-edit/session.jsonl b/examples/acp-agent/tests/snapshots/fs-edit/session.jsonl
index e4b84dee8c..1420353ae4 100644
--- a/examples/acp-agent/tests/snapshots/fs-edit/session.jsonl
+++ b/examples/acp-agent/tests/snapshots/fs-edit/session.jsonl
@@ -14,7 +14,7 @@
 {"type":"assistant/chunk","seq":68,"time":1783352086057,"data":{"turn":1,"step":1,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}
 {"type":"assistant/message","seq":69,"time":1783352086059,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"reasoning","text":"The user wants me to:\n1. Read config.txt in the current directory\n2. Use the edit tool to replace DEBUG with RELEASE\n3. Reply with exactly \"DONE\"\n\nLet me start by reading the file."},{"type":"tool-call","id":"call_00_S6krdIDHoSCGWv7WnXX97617","name":"read","arguments":"{\"file_path\": \"config.txt\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"36ebf262-429c-4398-abbc-a197e2522f1d"},"usage":{"inputTokens":2900,"outputTokens":91,"cacheReadTokens":0,"reasoningTokens":46}},"sourceEventSeqs":[5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68],"surfaceOp":"append"}
 {"type":"tool/call","seq":70,"time":1783352086059,"data":{"turn":1,"step":1,"callId":"call_00_S6krdIDHoSCGWv7WnXX97617","name":"read","arguments":"{\"file_path\": \"config.txt\"}"}}
-{"type":"tool/result","seq":71,"time":1783352086065,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_S6krdIDHoSCGWv7WnXX97617"},"content":[{"type":"tool-result","toolCallId":"call_00_S6krdIDHoSCGWv7WnXX97617","content":[{"type":"text","text":"<path>{{cwd}}/config.txt</path>\n<type>file</type>\n<content>\n1: mode=DEBUG\n2: level=info\n\n(End of file - total 2 lines)\n</content>"}],"isError":false}],"role":"user","id":"1c3ce978-55ee-4337-a586-084a77ed44e7"}},"sourceEventSeqs":[70],"surfaceOp":"append"}
+{"type":"tool/result","seq":71,"time":1783352086065,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_S6krdIDHoSCGWv7WnXX97617"},"content":[{"type":"tool-result","toolCallId":"call_00_S6krdIDHoSCGWv7WnXX97617","content":[{"type":"text","text":"<path>{{cwd}}/config.txt</path>\n<type>file</type>\n<content>\n1: mode=DEBUG\n2: level=info\n\n(End of file - total 2 lines)\n</content>"}],"isError":false}],"role":"user","id":"1c3ce978-55ee-4337-a586-084a77ed44e7"},"meta":{"path":"{{cwd}}/config.txt","offset":1,"lines":[{"number":1,"text":"mode=DEBUG"},{"number":2,"text":"level=info"}],"totalLines":2}},"sourceEventSeqs":[70],"surfaceOp":"append"}
 {"type":"step/end","seq":72,"time":1783352086065,"data":{"turn":1,"step":1}}
 {"type":"step/start","seq":73,"time":1783352086066,"data":{"turn":1,"step":2}}
 {"type":"assistant/chunk","seq":74,"time":1783352086901,"data":{"turn":1,"step":2,"chunk":{"type":"block-start","index":0,"blockType":"reasoning"}}}
diff --git a/examples/acp-agent/tests/snapshots/fs-policy-reject/session.jsonl b/examples/acp-agent/tests/snapshots/fs-policy-reject/session.jsonl
index 7ff933ab4b..f58a07edfe 100644
--- a/examples/acp-agent/tests/snapshots/fs-policy-reject/session.jsonl
+++ b/examples/acp-agent/tests/snapshots/fs-policy-reject/session.jsonl
@@ -27,7 +27,7 @@
 {"type":"assistant/chunk","seq":143,"time":1783611705572,"data":{"turn":1,"step":2,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}
 {"type":"assistant/message","seq":144,"time":1783611705573,"data":{"turn":1,"step":2,"message":{"role":"assistant","content":[{"type":"reasoning","text":"The edit tool requires reading the file first. The user said \"Do not read the file first\" but the tool's own constraints require reading. I need to follow the tool requirements. Let me read the file first."},{"type":"tool-call","id":"call_00_tfr0gdIclW92oIEgi7NF0891","name":"read","arguments":"{\"file_path\": \"settings.txt\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"de588e3c-b10c-4eee-93a5-26e9a665dcbc"},"usage":{"inputTokens":235,"outputTokens":89,"cacheReadTokens":3072,"reasoningTokens":44}},"sourceEventSeqs":[82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143],"surfaceOp":"append"}
 {"type":"tool/call","seq":145,"time":1783611705573,"data":{"turn":1,"step":2,"callId":"call_00_tfr0gdIclW92oIEgi7NF0891","name":"read","arguments":"{\"file_path\": \"settings.txt\"}"}}
-{"type":"tool/result","seq":146,"time":1783611705579,"data":{"turn":1,"step":2,"message":{"source":{"kind":"tool","callId":"call_00_tfr0gdIclW92oIEgi7NF0891"},"content":[{"type":"tool-result","toolCallId":"call_00_tfr0gdIclW92oIEgi7NF0891","content":[{"type":"text","text":"<path>{{cwd}}/settings.txt</path>\n<type>file</type>\n<content>\n1: color: blue\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"fade9382-14c7-47e3-8da4-286008d7e9b8"}},"sourceEventSeqs":[145],"surfaceOp":"append"}
+{"type":"tool/result","seq":146,"time":1783611705579,"data":{"turn":1,"step":2,"message":{"source":{"kind":"tool","callId":"call_00_tfr0gdIclW92oIEgi7NF0891"},"content":[{"type":"tool-result","toolCallId":"call_00_tfr0gdIclW92oIEgi7NF0891","content":[{"type":"text","text":"<path>{{cwd}}/settings.txt</path>\n<type>file</type>\n<content>\n1: color: blue\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"fade9382-14c7-47e3-8da4-286008d7e9b8"},"meta":{"path":"{{cwd}}/settings.txt","offset":1,"lines":[{"number":1,"text":"color: blue"}],"totalLines":1}},"sourceEventSeqs":[145],"surfaceOp":"append"}
 {"type":"step/end","seq":147,"time":1783611705579,"data":{"turn":1,"step":2}}
 {"type":"step/start","seq":148,"time":1783611705579,"data":{"turn":1,"step":3}}
 {"type":"assistant/chunk","seq":149,"time":1783611706200,"data":{"turn":1,"step":3,"chunk":{"type":"block-start","index":0,"blockType":"reasoning"}}}
diff --git a/examples/acp-agent/tests/snapshots/fs-read-window/session.jsonl b/examples/acp-agent/tests/snapshots/fs-read-window/session.jsonl
index 58cb8c5f34..33b0a2754f 100644
--- a/examples/acp-agent/tests/snapshots/fs-read-window/session.jsonl
+++ b/examples/acp-agent/tests/snapshots/fs-read-window/session.jsonl
@@ -14,7 +14,7 @@
 {"type":"assistant/chunk","seq":90,"time":1783352101346,"data":{"turn":1,"step":1,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}
 {"type":"assistant/message","seq":91,"time":1783352101348,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"reasoning","text":"The user wants me to use the read tool with offset 5 and limit 4 to read lines 5 through 8 of big.txt in the current directory. Then reply with exactly the single word DONE.\n\nLet me first check the current directory, then read the file."},{"type":"tool-call","id":"call_00_GIZwZS9a7vhWTFCIc7Z35497","name":"read","arguments":"{\"file_path\": \"big.txt\", \"offset\": 5, \"limit\": 4}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"5620412c-8fae-4d17-aac4-0801f3b02461"},"usage":{"inputTokens":2894,"outputTokens":133,"cacheReadTokens":0,"reasoningTokens":56}},"sourceEventSeqs":[5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90],"surfaceOp":"append"}
 {"type":"tool/call","seq":92,"time":1783352101348,"data":{"turn":1,"step":1,"callId":"call_00_GIZwZS9a7vhWTFCIc7Z35497","name":"read","arguments":"{\"file_path\": \"big.txt\", \"offset\": 5, \"limit\": 4}"}}
-{"type":"tool/result","seq":93,"time":1783352101353,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_GIZwZS9a7vhWTFCIc7Z35497"},"content":[{"type":"tool-result","toolCallId":"call_00_GIZwZS9a7vhWTFCIc7Z35497","content":[{"type":"text","text":"<path>{{cwd}}/big.txt</path>\n<type>file</type>\n<content>\n5: line five\n6: line six\n7: line seven\n8: line eight\n\n(Showing lines 5-8 of 10. Use offset=9 to continue.)\n</content>"}],"isError":false}],"role":"user","id":"02513672-93cb-4f70-9ee7-ad19542a5f6b"}},"sourceEventSeqs":[92],"surfaceOp":"append"}
+{"type":"tool/result","seq":93,"time":1783352101353,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_GIZwZS9a7vhWTFCIc7Z35497"},"content":[{"type":"tool-result","toolCallId":"call_00_GIZwZS9a7vhWTFCIc7Z35497","content":[{"type":"text","text":"<path>{{cwd}}/big.txt</path>\n<type>file</type>\n<content>\n5: line five\n6: line six\n7: line seven\n8: line eight\n\n(Showing lines 5-8 of 10. Use offset=9 to continue.)\n</content>"}],"isError":false}],"role":"user","id":"02513672-93cb-4f70-9ee7-ad19542a5f6b"},"meta":{"path":"{{cwd}}/big.txt","offset":5,"lines":[{"number":5,"text":"line five"},{"number":6,"text":"line six"},{"number":7,"text":"line seven"},{"number":8,"text":"line eight"}],"totalLines":10}},"sourceEventSeqs":[92],"surfaceOp":"append"}
 {"type":"step/end","seq":94,"time":1783352101353,"data":{"turn":1,"step":1}}
 {"type":"step/start","seq":95,"time":1783352101354,"data":{"turn":1,"step":2}}
 {"type":"assistant/chunk","seq":96,"time":1783352102021,"data":{"turn":1,"step":2,"chunk":{"type":"block-start","index":0,"blockType":"reasoning"}}}
diff --git a/examples/acp-agent/tests/snapshots/fs-read/session.jsonl b/examples/acp-agent/tests/snapshots/fs-read/session.jsonl
index 70c0f679bd..9d16f66531 100644
--- a/examples/acp-agent/tests/snapshots/fs-read/session.jsonl
+++ b/examples/acp-agent/tests/snapshots/fs-read/session.jsonl
@@ -14,7 +14,7 @@
 {"type":"assistant/chunk","seq":52,"time":1783352073705,"data":{"turn":1,"step":1,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}
 {"type":"assistant/message","seq":53,"time":1783352073708,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"reasoning","text":"The user wants me to read the file greeting.txt using the read tool (not bash), then reply with exactly the single word \"DONE\"."},{"type":"tool-call","id":"call_00_hHPZCcivsIkXAGS9jTGy8417","name":"read","arguments":"{\"file_path\": \"greeting.txt\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"5452254c-4843-458c-9732-12fe8b7c1468"},"usage":{"inputTokens":2882,"outputTokens":75,"cacheReadTokens":0,"reasoningTokens":29}},"sourceEventSeqs":[5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52],"surfaceOp":"append"}
 {"type":"tool/call","seq":54,"time":1783352073709,"data":{"turn":1,"step":1,"callId":"call_00_hHPZCcivsIkXAGS9jTGy8417","name":"read","arguments":"{\"file_path\": \"greeting.txt\"}"}}
-{"type":"tool/result","seq":55,"time":1783352073717,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_hHPZCcivsIkXAGS9jTGy8417"},"content":[{"type":"tool-result","toolCallId":"call_00_hHPZCcivsIkXAGS9jTGy8417","content":[{"type":"text","text":"<path>{{cwd}}/greeting.txt</path>\n<type>file</type>\n<content>\n1: hello\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"6dd015cf-8c8b-4fd3-a1b2-fa243d67d8e9"}},"sourceEventSeqs":[54],"surfaceOp":"append"}
+{"type":"tool/result","seq":55,"time":1783352073717,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_hHPZCcivsIkXAGS9jTGy8417"},"content":[{"type":"tool-result","toolCallId":"call_00_hHPZCcivsIkXAGS9jTGy8417","content":[{"type":"text","text":"<path>{{cwd}}/greeting.txt</path>\n<type>file</type>\n<content>\n1: hello\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"6dd015cf-8c8b-4fd3-a1b2-fa243d67d8e9"},"meta":{"path":"{{cwd}}/greeting.txt","offset":1,"lines":[{"number":1,"text":"hello"}],"totalLines":1}},"sourceEventSeqs":[54],"surfaceOp":"append"}
 {"type":"step/end","seq":56,"time":1783352073718,"data":{"turn":1,"step":1}}
 {"type":"step/start","seq":57,"time":1783352073719,"data":{"turn":1,"step":2}}
 {"type":"assistant/chunk","seq":58,"time":1783352074666,"data":{"turn":1,"step":2,"chunk":{"type":"block-start","index":0,"blockType":"reasoning"}}}
diff --git a/examples/acp-agent/tests/snapshots/fs-write-overwrite/session.jsonl b/examples/acp-agent/tests/snapshots/fs-write-overwrite/session.jsonl
index e836616e19..4fdc8bae84 100644
--- a/examples/acp-agent/tests/snapshots/fs-write-overwrite/session.jsonl
+++ b/examples/acp-agent/tests/snapshots/fs-write-overwrite/session.jsonl
@@ -14,7 +14,7 @@
 {"type":"assistant/chunk","seq":64,"time":1783352093614,"data":{"turn":1,"step":1,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}
 {"type":"assistant/message","seq":65,"time":1783352093617,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"reasoning","text":"The user wants me to:\n1. Read data.txt using the read tool\n2. Replace its entire contents with exactly \"replaced\" using the write tool\n3. Reply with exactly \"DONE\""},{"type":"tool-call","id":"call_00_n4eRJuGoxNR07svgNtk82243","name":"read","arguments":"{\"file_path\": \"data.txt\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"00272d0c-8ed0-436a-8d10-4a7091447dfe"},"usage":{"inputTokens":2899,"outputTokens":87,"cacheReadTokens":0,"reasoningTokens":42}},"sourceEventSeqs":[5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64],"surfaceOp":"append"}
 {"type":"tool/call","seq":66,"time":1783352093617,"data":{"turn":1,"step":1,"callId":"call_00_n4eRJuGoxNR07svgNtk82243","name":"read","arguments":"{\"file_path\": \"data.txt\"}"}}
-{"type":"tool/result","seq":67,"time":1783352093624,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_n4eRJuGoxNR07svgNtk82243"},"content":[{"type":"tool-result","toolCallId":"call_00_n4eRJuGoxNR07svgNtk82243","content":[{"type":"text","text":"<path>{{cwd}}/data.txt</path>\n<type>file</type>\n<content>\n1: original contents\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"c14ef7fe-2bb8-4adf-ab15-5a988fbf5f55"}},"sourceEventSeqs":[66],"surfaceOp":"append"}
+{"type":"tool/result","seq":67,"time":1783352093624,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_n4eRJuGoxNR07svgNtk82243"},"content":[{"type":"tool-result","toolCallId":"call_00_n4eRJuGoxNR07svgNtk82243","content":[{"type":"text","text":"<path>{{cwd}}/data.txt</path>\n<type>file</type>\n<content>\n1: original contents\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"c14ef7fe-2bb8-4adf-ab15-5a988fbf5f55"},"meta":{"path":"{{cwd}}/data.txt","offset":1,"lines":[{"number":1,"text":"original contents"}],"totalLines":1}},"sourceEventSeqs":[66],"surfaceOp":"append"}
 {"type":"step/end","seq":68,"time":1783352093624,"data":{"turn":1,"step":1}}
 {"type":"step/start","seq":69,"time":1783352093625,"data":{"turn":1,"step":2}}
 {"type":"assistant/chunk","seq":70,"time":1783352094455,"data":{"turn":1,"step":2,"chunk":{"type":"block-start","index":0,"blockType":"reasoning"}}}
diff --git a/examples/acp-agent/tests/snapshots/parallel-tool-calls/session.jsonl b/examples/acp-agent/tests/snapshots/parallel-tool-calls/session.jsonl
index d4cca7a82c..7c22270112 100644
--- a/examples/acp-agent/tests/snapshots/parallel-tool-calls/session.jsonl
+++ b/examples/acp-agent/tests/snapshots/parallel-tool-calls/session.jsonl
@@ -15,8 +15,8 @@
 {"type":"assistant/message","seq":13,"time":0,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"tool-call","id":"call_read_a","name":"read","arguments":"{\"file_path\":\"a.txt\"}"},{"type":"tool-call","id":"call_read_b","name":"read","arguments":"{\"file_path\":\"b.txt\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"380ff5b4-d7f1-4c36-b87d-9a42ce1b264c"},"usage":{"inputTokens":10,"outputTokens":5}},"sourceEventSeqs":[5,6,7,8,9,10,11,12],"surfaceOp":"append"}
 {"type":"tool/call","seq":14,"time":0,"data":{"turn":1,"step":1,"callId":"call_read_a","name":"read","arguments":"{\"file_path\":\"a.txt\"}"}}
 {"type":"tool/call","seq":15,"time":0,"data":{"turn":1,"step":1,"callId":"call_read_b","name":"read","arguments":"{\"file_path\":\"b.txt\"}"}}
-{"type":"tool/result","seq":16,"time":0,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_read_a"},"content":[{"type":"tool-result","toolCallId":"call_read_a","content":[{"type":"text","text":"<path>{{cwd}}/a.txt</path>\n<type>file</type>\n<content>\n1: alpha\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"ccdf47d2-0e79-4ca6-a70f-2c8c42e2341e"}},"sourceEventSeqs":[14],"surfaceOp":"append"}
-{"type":"tool/result","seq":17,"time":0,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_read_b"},"content":[{"type":"tool-result","toolCallId":"call_read_b","content":[{"type":"text","text":"<path>{{cwd}}/b.txt</path>\n<type>file</type>\n<content>\n1: beta\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"49a6bffd-3a0e-490e-bf49-e9d3e6370f83"}},"sourceEventSeqs":[15],"surfaceOp":"append"}
+{"type":"tool/result","seq":16,"time":0,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_read_a"},"content":[{"type":"tool-result","toolCallId":"call_read_a","content":[{"type":"text","text":"<path>{{cwd}}/a.txt</path>\n<type>file</type>\n<content>\n1: alpha\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"ccdf47d2-0e79-4ca6-a70f-2c8c42e2341e"},"meta":{"path":"{{cwd}}/a.txt","offset":1,"lines":[{"number":1,"text":"alpha"}],"totalLines":1}},"sourceEventSeqs":[14],"surfaceOp":"append"}
+{"type":"tool/result","seq":17,"time":0,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_read_b"},"content":[{"type":"tool-result","toolCallId":"call_read_b","content":[{"type":"text","text":"<path>{{cwd}}/b.txt</path>\n<type>file</type>\n<content>\n1: beta\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"49a6bffd-3a0e-490e-bf49-e9d3e6370f83"},"meta":{"path":"{{cwd}}/b.txt","offset":1,"lines":[{"number":1,"text":"beta"}],"totalLines":1}},"sourceEventSeqs":[15],"surfaceOp":"append"}
 {"type":"step/end","seq":18,"time":0,"data":{"turn":1,"step":1}}
 {"type":"step/start","seq":19,"time":0,"data":{"turn":1,"step":2}}
 {"type":"assistant/chunk","seq":20,"time":0,"data":{"turn":1,"step":2,"chunk":{"type":"block-start","index":0,"blockType":"text"}}}
diff --git a/examples/acp-agent/tests/snapshots/workspace-context/session.jsonl b/examples/acp-agent/tests/snapshots/workspace-context/session.jsonl
index 832916d334..f2157a27fe 100644
--- a/examples/acp-agent/tests/snapshots/workspace-context/session.jsonl
+++ b/examples/acp-agent/tests/snapshots/workspace-context/session.jsonl
@@ -12,7 +12,7 @@
 {"type":"assistant/chunk","seq":10,"time":1784903339801,"data":{"turn":1,"step":1,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}
 {"type":"assistant/message","seq":11,"time":1784903339801,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"tool-call","id":"call_workspace_read","name":"read","arguments":"{\"file_path\":\"nested/task.txt\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"2093472f-8f2c-4cfd-8d71-515e3242dad2"},"usage":{"inputTokens":10,"outputTokens":5}},"sourceEventSeqs":[6,7,8,9,10],"surfaceOp":"append"}
 {"type":"tool/call","seq":12,"time":1784903339802,"data":{"turn":1,"step":1,"callId":"call_workspace_read","name":"read","arguments":"{\"file_path\":\"nested/task.txt\"}"}}
-{"type":"tool/result","seq":13,"time":1784903339813,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_workspace_read"},"content":[{"type":"tool-result","toolCallId":"call_workspace_read","content":[{"type":"text","text":"<path>{{cwd}}/nested/task.txt</path>\n<type>file</type>\n<content>\n1: snapshot task\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"d9a6b9c3-715b-42b0-9d20-04319a83eea8"}},"sourceEventSeqs":[12],"surfaceOp":"append"}
+{"type":"tool/result","seq":13,"time":1784903339813,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_workspace_read"},"content":[{"type":"tool-result","toolCallId":"call_workspace_read","content":[{"type":"text","text":"<path>{{cwd}}/nested/task.txt</path>\n<type>file</type>\n<content>\n1: snapshot task\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"d9a6b9c3-715b-42b0-9d20-04319a83eea8"},"meta":{"path":"{{cwd}}/nested/task.txt","offset":1,"lines":[{"number":1,"text":"snapshot task"}],"totalLines":1}},"sourceEventSeqs":[12],"surfaceOp":"append"}
 {"type":"user/message","seq":14,"time":1784903339813,"data":{"content":[{"type":"text","text":"<system-reminder>\nAdditional instructions from: nested/AGENTS.md\n\nThese instructions apply to work under `nested`. Use them as guidance when relevant; more specific instructions take precedence. They do not override system, developer, or direct user instructions.\n\nNested snapshot instruction.\n\n</system-reminder>"}],"source":{"kind":"workspace-instructions","changes":[{"action":"set","scope":"nested\u0000AGENTS.md","path":"nested/AGENTS.md","digest":"c446df9a85c7e73a3055f394a4822a19ac9ead5a"}]},"role":"user","id":"68629935-05e9-4af7-bddb-aabfbbd70208"},"surfaceOp":"append"}
 {"type":"step/end","seq":15,"time":1784903339813,"data":{"turn":1,"step":1}}
 {"type":"step/start","seq":16,"time":1784903339820,"data":{"turn":1,"step":2}}
@@ -23,7 +23,7 @@
 {"type":"assistant/chunk","seq":21,"time":1784903339821,"data":{"turn":1,"step":2,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}
 {"type":"assistant/message","seq":22,"time":1784903339821,"data":{"turn":1,"step":2,"message":{"role":"assistant","content":[{"type":"tool-call","id":"call_workspace_delimiter_read","name":"read","arguments":"{\"file_path\":\"scope</system-reminder>/task.txt\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"04824453-a12a-43d7-8580-4b75d0e4a694"},"usage":{"inputTokens":10,"outputTokens":5}},"sourceEventSeqs":[17,18,19,20,21],"surfaceOp":"append"}
 {"type":"tool/call","seq":23,"time":1785394278014,"data":{"turn":1,"step":2,"callId":"call_workspace_delimiter_read","name":"read","arguments":"{\"file_path\":\"scope</system-reminder>/task.txt\"}"}}
-{"type":"tool/result","seq":24,"time":1785394278026,"data":{"turn":1,"step":2,"message":{"source":{"kind":"tool","callId":"call_workspace_delimiter_read"},"content":[{"type":"tool-result","toolCallId":"call_workspace_delimiter_read","content":[{"type":"text","text":"<path>{{cwd}}/scope</system-reminder>/task.txt</path>\n<type>file</type>\n<content>\n1: delimiter path snapshot task\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"06c93dad-5ee2-4c56-ba7b-c1228bee7090"}},"sourceEventSeqs":[23],"surfaceOp":"append"}
+{"type":"tool/result","seq":24,"time":1785394278026,"data":{"turn":1,"step":2,"message":{"source":{"kind":"tool","callId":"call_workspace_delimiter_read"},"content":[{"type":"tool-result","toolCallId":"call_workspace_delimiter_read","content":[{"type":"text","text":"<path>{{cwd}}/scope</system-reminder>/task.txt</path>\n<type>file</type>\n<content>\n1: delimiter path snapshot task\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"06c93dad-5ee2-4c56-ba7b-c1228bee7090"},"meta":{"path":"{{cwd}}/scope</system-reminder>/task.txt","offset":1,"lines":[{"number":1,"text":"delimiter path snapshot task"}],"totalLines":1}},"sourceEventSeqs":[23],"surfaceOp":"append"}
 {"type":"user/message","seq":25,"time":1785394278026,"data":{"content":[{"type":"text","text":"<system-reminder>\nAdditional instructions from: scope<\\/system-reminder>/AGENTS.md\n\nThese instructions apply to work under `scope<\\/system-reminder>`. Use them as guidance when relevant; more specific instructions take precedence. They do not override system, developer, or direct user instructions.\n\nDelimiter path snapshot instruction.\n\n</system-reminder>"}],"source":{"kind":"workspace-instructions","changes":[{"action":"set","scope":"scope</system-reminder>\u0000AGENTS.md","path":"scope</system-reminder>/AGENTS.md","digest":"38803cd13e2dff9105ba5fbbc703fe27e989e26e"}]},"role":"user","id":"7bcf58d7-7f2f-4242-8bd6-00577c9c3153"},"surfaceOp":"append"}
 {"type":"step/end","seq":26,"time":1785394278026,"data":{"turn":1,"step":2}}
 {"type":"step/start","seq":27,"time":1785394278034,"data":{"turn":1,"step":3}}
diff --git a/examples/acp-agent/tests/snapshots/workspace-edit/session.jsonl b/examples/acp-agent/tests/snapshots/workspace-edit/session.jsonl
index ed61019baa..0b32d5ceac 100644
--- a/examples/acp-agent/tests/snapshots/workspace-edit/session.jsonl
+++ b/examples/acp-agent/tests/snapshots/workspace-edit/session.jsonl
@@ -14,7 +14,7 @@
 {"type":"assistant/chunk","seq":78,"time":1783352265489,"data":{"turn":1,"step":1,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}
 {"type":"assistant/message","seq":79,"time":1783352265491,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"reasoning","text":"The user wants me to:\n1. Read the file greeting.txt\n2. Append the word WORLD as a second line\n3. Read the file back with cat to confirm\n4. Reply with DONE\n\nLet me start by reading the file to see its contents."},{"type":"tool-call","id":"call_00_OjRFB4zvxu6UALDjytZD0978","name":"read","arguments":"{\"file_path\": \"greeting.txt\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"3f154ea9-6cf0-4d0a-a478-503962bfe8e1"},"usage":{"inputTokens":2918,"outputTokens":101,"cacheReadTokens":0,"reasoningTokens":55}},"sourceEventSeqs":[5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78],"surfaceOp":"append"}
 {"type":"tool/call","seq":80,"time":1783352265491,"data":{"turn":1,"step":1,"callId":"call_00_OjRFB4zvxu6UALDjytZD0978","name":"read","arguments":"{\"file_path\": \"greeting.txt\"}"}}
-{"type":"tool/result","seq":81,"time":1783352265504,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_OjRFB4zvxu6UALDjytZD0978"},"content":[{"type":"tool-result","toolCallId":"call_00_OjRFB4zvxu6UALDjytZD0978","content":[{"type":"text","text":"<path>{{cwd}}/greeting.txt</path>\n<type>file</type>\n<content>\n1: hello\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"59ffbde4-d450-4564-a907-beeec29af0d0"}},"sourceEventSeqs":[80],"surfaceOp":"append"}
+{"type":"tool/result","seq":81,"time":1783352265504,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_OjRFB4zvxu6UALDjytZD0978"},"content":[{"type":"tool-result","toolCallId":"call_00_OjRFB4zvxu6UALDjytZD0978","content":[{"type":"text","text":"<path>{{cwd}}/greeting.txt</path>\n<type>file</type>\n<content>\n1: hello\n\n(End of file - total 1 lines)\n</content>"}],"isError":false}],"role":"user","id":"59ffbde4-d450-4564-a907-beeec29af0d0"},"meta":{"path":"{{cwd}}/greeting.txt","offset":1,"lines":[{"number":1,"text":"hello"}],"totalLines":1}},"sourceEventSeqs":[80],"surfaceOp":"append"}
 {"type":"step/end","seq":82,"time":1783352265504,"data":{"turn":1,"step":1}}
 {"type":"step/start","seq":83,"time":1783352265505,"data":{"turn":1,"step":2}}
 {"type":"assistant/chunk","seq":84,"time":1783352266385,"data":{"turn":1,"step":2,"chunk":{"type":"block-start","index":0,"blockType":"reasoning"}}}
diff --git a/packages/cordis/tool-cordis/src/api-catalog.ts b/packages/cordis/tool-cordis/src/api-catalog.ts
index 66ac086b49..098e00325d 100644
--- a/packages/cordis/tool-cordis/src/api-catalog.ts
+++ b/packages/cordis/tool-cordis/src/api-catalog.ts
@@ -2211,6 +2211,14 @@ export const TYPE_API: readonly TypeApiEntry[] = [
     name: 'PtyWaitReason',
     declaration: 'export type PtyWaitReason = \'stdin_read\' | \'inferred_idle\' | \'timeout\' | \'session_exit\';',
   },
+  {
+    name: 'ReadFileLine',
+    declaration: 'export interface ReadFileLine {\n    number: number;\n    text: string;\n}',
+  },
+  {
+    name: 'ReadResultView',
+    declaration: 'export interface ReadResultView {\n    card: \'read\';\n    title?: string;\n    path: string;\n    offset: number;\n    lines: ReadFileLine[];\n    totalLines: number;\n    lang?: string;\n    content?: ContentBlock[];\n}',
+  },
   {
     name: 'ReasoningBlock',
     declaration: 'export interface ReasoningBlock {\n    type: \'reasoning\';\n    text: string;\n}',
@@ -2849,7 +2857,7 @@ export const TYPE_API: readonly TypeApiEntry[] = [
   },
   {
     name: 'ToolResultView',
-    declaration: 'export type ToolResultView = GenericResultView | TerminalResultView | DiffResultView | WebResultView;',
+    declaration: 'export type ToolResultView = GenericResultView | TerminalResultView | DiffResultView | ReadResultView | WebResultView;',
   },
   {
     name: 'ToolRunContext',
diff --git a/packages/core/tools/README.i18n.yaml b/packages/core/tools/README.i18n.yaml
index e888160b0f..064f3f9e1f 100644
--- a/packages/core/tools/README.i18n.yaml
+++ b/packages/core/tools/README.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 packages/core/tools/README.md
-README.md: e7f395f8c1d6417db856e590f5267cf6887e4d12
-README.zh.md: acb4c047bf86e36c828882ff751d4be1f627f99e
+README.md: dcce455f9551318f3871e3df84c29789078fef7c
+README.zh.md: 63eaa2e0b66797c74a1d4845c29ca970b63f5f99
diff --git a/packages/core/tools/README.md b/packages/core/tools/README.md
index e7f395f8c1..dcce455f95 100644
--- a/packages/core/tools/README.md
+++ b/packages/core/tools/README.md
@@ -108,7 +108,7 @@ Optional `isConcurrencySafe(args)` receives typed, softly validated arguments. E
 Tools optionally own pure `presentCall()` and `presentResult()` render intents, so UIs do not special-case tool names:
 
 - Call views are `{ card: 'generic', title, kind?, rawInput?, content?, locations? }`, `{ card: 'terminal', title, description?, cwd? }`, or `{ card: 'diff', title, diffs, locations? }`.
-- Result views are `{ card: 'generic', title?, content? }`, `{ card: 'terminal', title?, output?, exitCode?, signal? }`, `{ card: 'diff', title?, diffs }`, or `{ card: 'web', kind: 'search' | 'fetch', title?, … }` (a completed web retrieval; the `kind` arms carry the structured search sources or the fetch summary, and a UI without the `web` capability falls back to the raw result content).
+- Result views are `{ card: 'generic', title?, content? }`, `{ card: 'terminal', title?, output?, exitCode?, signal? }`, `{ card: 'diff', title?, diffs }`, `{ card: 'read', title?, path, offset, lines, totalLines, lang?, content? }` (a completed file read → a line-numbered, optionally syntax-highlighted code view; `offset` is the 1-based first line the window requested, kept even when `lines` is empty; `lines` is `{ number, text }[]` keeping each file line number, and `content` is the envelope-stripped text a UI without read support falls back to), or `{ card: 'web', kind: 'search' | 'fetch', title?, … }` (a completed web retrieval; the `kind` arms carry the structured search sources or the fetch summary, and a UI without the `web` capability falls back to the raw result content).
 
 Returning `undefined` selects generic fallback. Presenters depend only on their arguments and the durable result because UIs call them during live streaming and log replay. `output.presentationMeta(args, value)` derives JSON metadata for direct surface calls; that metadata persists with `tool/result` and returns to `presentResult`, while the canonical value itself remains execution-local and is never replayed. Nested Code dispatches do not compute metadata. `defineTool` soft-validates older logged arguments and falls back instead of crashing replay. `dsh-tool-bash` and `dsh-tool-fs` are the reference implementations; the [canonical-output Agent Note](../../../.agents/notes/implemented/architecture/2026-07-20-canonical-tool-output-contract.md) owns the value/presentation split and the [render-intent Agent Note](../../../.agents/notes/implemented/architecture/2026-07-02-tool-render-intent-union.md) owns card vocabulary.
 
diff --git a/packages/core/tools/README.zh.md b/packages/core/tools/README.zh.md
index acb4c047bf..63eaa2e0b6 100644
--- a/packages/core/tools/README.zh.md
+++ b/packages/core/tools/README.zh.md
@@ -108,7 +108,7 @@ ctx.tools.register(defineTool({
 工具可以选择拥有纯 `presentCall()` 和 `presentResult()` 呈现意图，使 UI 无需特殊处理工具名称：
 
 - 调用视图为 `{ card: 'generic', title, kind?, rawInput?, content?, locations? }`、`{ card: 'terminal', title, description?, cwd? }` 或 `{ card: 'diff', title, diffs, locations? }`。
-- 结果视图为 `{ card: 'generic', title?, content? }`、`{ card: 'terminal', title?, output?, exitCode?, signal? }`、`{ card: 'diff', title?, diffs }` 或 `{ card: 'web', kind: 'search' | 'fetch', title?, … }`（已完成的 web 检索；`kind` 各分支携带结构化的搜索来源或抓取摘要，不具备 `web` 能力的 UI 回退到原始结果内容）。
+- 结果视图为 `{ card: 'generic', title?, content? }`、`{ card: 'terminal', title?, output?, exitCode?, signal? }`、`{ card: 'diff', title?, diffs }`、`{ card: 'read', title?, path, offset, lines, totalLines, lang?, content? }`（已完成的文件读取→带行号、可选语法高亮的代码视图；`offset` 是窗口请求的 1-based 起始行，即使 `lines` 为空也保留；`lines` 是 `{ number, text }[]`，保留每一行的文件行号，`content` 是无读取能力的 UI 回退时使用的去信封文本）或 `{ card: 'web', kind: 'search' | 'fetch', title?, … }`（已完成的 web 检索；`kind` 各分支携带结构化的搜索来源或抓取摘要，不具备 `web` 能力的 UI 回退到原始结果内容）。
 
 返回 `undefined` 会选择通用回退。呈现器只依赖其参数和持久结果，因为 UI 会在实时流式输出和日志回放期间调用它们。`output.presentationMeta(args, value)` 为直接接口调用派生 JSON 元数据；该元数据随 `tool/result` 持久化并传回 `presentResult`，而规范值本身仍只存在于执行局部，绝不会回放。嵌套 Code 分发不会计算元数据。`defineTool` 会软验证较旧的日志参数并回退，而不会使回放崩溃。`dsh-tool-bash` 与 `dsh-tool-fs` 是参考实现；[规范输出 Agent Note](../../../.agents/notes/implemented/architecture/2026-07-20-canonical-tool-output-contract.md) 规定值／呈现拆分，[呈现意图 Agent Note](../../../.agents/notes/implemented/architecture/2026-07-02-tool-render-intent-union.md) 规定卡片词汇。
 
diff --git a/packages/core/tools/src/index.ts b/packages/core/tools/src/index.ts
index e825a1a0dc..60dafed720 100644
--- a/packages/core/tools/src/index.ts
+++ b/packages/core/tools/src/index.ts
@@ -74,6 +74,7 @@ export type {
   ToolCallKind,
   FileLocation,
   FileDiff,
+  ReadFileLine,
   ToolCallView,
   GenericCallView,
   TerminalCallView,
@@ -82,6 +83,7 @@ export type {
   GenericResultView,
   TerminalResultView,
   DiffResultView,
+  ReadResultView,
   WebResultView,
   WebSearchResultView,
   WebFetchResultView,
diff --git a/packages/core/tools/src/presentation.ts b/packages/core/tools/src/presentation.ts
index d1e7d552b5..b2b24554c4 100644
--- a/packages/core/tools/src/presentation.ts
+++ b/packages/core/tools/src/presentation.ts
@@ -117,6 +117,18 @@ export interface DiffCallView {
   locations?: FileLocation[]
 }
 
+/**
+ * One numbered line of a file, the unit a {@link ReadResultView} carries so a
+ * capable UI can render a syntax-highlighted, line-numbered code view. `number`
+ * is the 1-based line number in the file (a window past `offset` keeps the file's
+ * own numbering, not a 1-based re-count); `text` is the line without its trailing
+ * newline, already truncated to the read tool's per-line cap.
+ */
+export interface ReadFileLine {
+  number: number
+  text: string
+}
+
 /**
  * How a tool wants the COMPLETED call shown — the *result* state, after `execute`
  * returns. A `card`-tagged union mirroring {@link ToolCallView}: a UI switches on
@@ -125,7 +137,7 @@ export interface DiffCallView {
  * `ToolDefinition.presentResult`; omitting the method keeps the pending
  * title and renders the raw result content.
  */
-export type ToolResultView = GenericResultView | TerminalResultView | DiffResultView | WebResultView
+export type ToolResultView = GenericResultView | TerminalResultView | DiffResultView | ReadResultView | WebResultView
 
 /**
  * The default completed card: an optional replacement title and reformatted
@@ -177,6 +189,47 @@ export interface DiffResultView {
   diffs: FileDiff[]
 }
 
+/**
+ * A completed file read rendered as a line-numbered, optionally syntax-highlighted
+ * code view by a capable UI. Set by a tool whose call reads file text (e.g.
+ * `read`); the pending state stays a {@link GenericCallView} (`kind: 'read'`)
+ * because a call carries no content until `execute` returns. The structured
+ * `lines`/`path`/`lang`/`totalLines` fields cannot be reconstructed from the
+ * model-facing result text alone, so the read tool projects them through its
+ * `output.presentationMeta` (persisted with the session log) and `presentResult`
+ * narrows that metadata back into this view on live and replay paths alike. A UI
+ * without the read capability falls back to `content` (the model-facing text with
+ * its envelope stripped), so this view degrades to the generic text card.
+ */
+export interface ReadResultView {
+  card: 'read'
+  /** Replacement title for the completed call. Omit to keep the pending-state title. */
+  title?: string
+  /** The read file's path (the model-facing path; the bridge relativizes it). */
+  path: string
+  /**
+   * The 1-based first line the window requested, preserved even when `lines` is
+   * empty (a byte cap below the first selected line yields an empty window) so a
+   * UI knows where the window starts and where a continuation resumes.
+   */
+  offset: number
+  /** The returned window's lines, in file order, each keeping its file line number. */
+  lines: ReadFileLine[]
+  /** Exact total line count in the file, so a UI can show a "showing N of M" affordance. */
+  totalLines: number
+  /**
+   * A syntax-highlighting language hint derived from the file extension (e.g.
+   * `ts`, `py`), or omitted when the extension maps to no known language so a UI
+   * renders the lines as plain text.
+   */
+  lang?: string
+  /**
+   * The model-facing result content with its envelope stripped, for a UI without
+   * the read capability. Omit to let such a UI render the raw result content.
+   */
+  content?: ContentBlock[]
+}
+
 /**
  * One citeable source in a completed {@link WebSearchResultView}, the faithful
  * projection of one web-search source. The presentation projection of `dsh-web`'s
diff --git a/packages/fs/tool-fs/README.i18n.yaml b/packages/fs/tool-fs/README.i18n.yaml
index a3ebe97bc4..65c6b65268 100644
--- a/packages/fs/tool-fs/README.i18n.yaml
+++ b/packages/fs/tool-fs/README.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 packages/fs/tool-fs/README.md
-README.md: 4ff9b043525e8e7a0b59e3d91410951d88bb9a69
-README.zh.md: ce93e10072d74ce268273aa472bfbb3f34f46259
+README.md: c00b59fed06249e6d9479c4a809cdf7d78f93239
+README.zh.md: f90fbb36391c1388ab0f6836daa2a9061d046be6
diff --git a/packages/fs/tool-fs/README.md b/packages/fs/tool-fs/README.md
index 4ff9b04352..c00b59fed0 100644
--- a/packages/fs/tool-fs/README.md
+++ b/packages/fs/tool-fs/README.md
@@ -34,7 +34,7 @@ All keys are optional; the defaults are the shipped read caps.
 
 Field names are snake_case to match Claude Code and existing harness tool schemas.
 
-Canonical successes are `read` → `{ path, offset, lines: [{ number, text }], totalLines }`, `write` → `{ path, operation: 'create' | 'update', before: string | null, after }`, and `edit` → `{ path, before, after }`. Native renderers preserve the line-numbered read and mutation acknowledgements below. Write/edit derive replayable diff-card metadata from these values; the values themselves are execution-local and are not added to `tool/result`.
+Canonical successes are `read` → `{ path, offset, lines: [{ number, text }], totalLines }`, `write` → `{ path, operation: 'create' | 'update', before: string | null, after }`, and `edit` → `{ path, before, after }`. Native renderers preserve the line-numbered read and mutation acknowledgements below. `write`/`edit` derive replayable diff-card metadata, and `read` derives a replayable read-card window `{ path, offset, lines, totalLines, lang? }`, from these canonical values; the canonical values themselves are execution-local and are not added to `tool/result`, only the derived presentation metadata is persisted.
 
 ## The tool is the executor; policy is an event gate
 
diff --git a/packages/fs/tool-fs/README.zh.md b/packages/fs/tool-fs/README.zh.md
index ce93e10072..f90fbb3639 100644
--- a/packages/fs/tool-fs/README.zh.md
+++ b/packages/fs/tool-fs/README.zh.md
@@ -34,7 +34,7 @@ await ctx.plugin(ToolFs)                                  // this package — re
 
 字段名使用 snake_case，与 Claude Code 和现有 harness 工具 schema 一致。
 
-规范成功值分别为：`read` → `{ path, offset, lines: [{ number, text }], totalLines }`，`write` → `{ path, operation: 'create' | 'update', before: string | null, after }`，`edit` → `{ path, before, after }`。原生渲染器会保留下方带行号的读取结果和变更确认。写入/编辑从这些值派生可回放的 diff 卡片元数据；这些值本身仅限于本次执行，不会添加到 `tool/result`。
+规范成功值分别为：`read` → `{ path, offset, lines: [{ number, text }], totalLines }`，`write` → `{ path, operation: 'create' | 'update', before: string | null, after }`，`edit` → `{ path, before, after }`。原生渲染器会保留下方带行号的读取结果和变更确认。`write`/`edit` 从这些规范值派生可回放的 diff 卡片元数据，`read` 派生可回放的读取卡片窗口 `{ path, offset, lines, totalLines, lang? }`；规范值本身仅限于本次执行，不会添加到 `tool/result`，只有派生出的呈现元数据会被持久化。
 
 ## 工具就是执行器；策略是事件门禁
 
diff --git a/packages/fs/tool-fs/src/read-render.ts b/packages/fs/tool-fs/src/read-render.ts
index 7e581bb22c..19b6c0b1e7 100644
--- a/packages/fs/tool-fs/src/read-render.ts
+++ b/packages/fs/tool-fs/src/read-render.ts
@@ -168,3 +168,105 @@ export function formatReadOutput(displayPath: string, outcome: FileReadOutcome):
 ${body}
 </content>`
 }
+
+/**
+ * Lowercased file-extension to syntax-highlighting language hint. Keys are the
+ * extension without its dot; a UI treats an absent key as plain text. The map is
+ * intentionally small — common source, config, and markup extensions a
+ * line-numbered code view benefits from highlighting — not an exhaustive registry.
+ */
+const LANG_BY_EXTENSION: Readonly<Record<string, string>> = {
+  ts: 'ts', tsx: 'tsx', mts: 'ts', cts: 'ts',
+  js: 'js', jsx: 'jsx', mjs: 'js', cjs: 'js',
+  json: 'json', jsonc: 'json',
+  py: 'py', rb: 'rb', go: 'go', rs: 'rs', java: 'java',
+  c: 'c', h: 'c', cc: 'cpp', cpp: 'cpp', hpp: 'cpp', cxx: 'cpp',
+  cs: 'cs', kt: 'kotlin', swift: 'swift', php: 'php',
+  sh: 'sh', bash: 'sh', zsh: 'sh',
+  yaml: 'yaml', yml: 'yaml', toml: 'toml', ini: 'ini',
+  md: 'md', markdown: 'md', mdx: 'mdx',
+  html: 'html', htm: 'html', css: 'css', scss: 'scss', less: 'less',
+  sql: 'sql', xml: 'xml', lua: 'lua',
+}
+
+/**
+ * Derive a syntax-highlighting language hint from a read path's file extension.
+ * Pure and case-insensitive on the extension; a dotfile with no extension
+ * (`.gitignore`) and an unknown extension both yield `undefined`.
+ * @param path - the model-facing path the read reported.
+ * @returns the language hint for {@link LANG_BY_EXTENSION}, or `undefined` when the extension maps to none.
+ */
+export function langFromPath(path: string): string | undefined {
+  const base = path.slice(Math.max(path.lastIndexOf('/'), path.lastIndexOf('\\')) + 1)
+  const dot = base.lastIndexOf('.')
+  // A leading dot is a dotfile (no extension), not an empty extension.
+  if (dot <= 0) return undefined
+  const ext = base.slice(dot + 1).toLowerCase()
+  // Own-property check only: a filename whose extension is an Object.prototype
+  // key (`foo.constructor`, `foo.__proto__`) must map to no language, not to the
+  // inherited member — otherwise a function would reach `lang` and fail the
+  // tool-output JSON validation.
+  return Object.hasOwn(LANG_BY_EXTENSION, ext) ? LANG_BY_EXTENSION[ext] : undefined
+}
+
+/**
+ * The `read` tool's private `tool/result` `meta` payload: the structured
+ * line-numbered window a capable UI renders as a code view. Attached opaquely (as
+ * `unknown`) on the tool result and persisted with the session log — it must be
+ * JSON-serializable (the session validates this at `append`), so `presentResult`
+ * reproduces the read card on replay when the raw structured output is no longer
+ * on the wire. The producing tool owns and narrows this opaque shape.
+ */
+export interface FsReadMeta {
+  /** The read file's model-facing path. */
+  path: string
+  /** The 1-based first line the window requested, kept even when `lines` is empty. */
+  offset: number
+  /** The returned window's lines, each keeping its file line number. */
+  lines: FileTextLine[]
+  /** Exact total line count in the file. */
+  totalLines: number
+  /** Syntax-highlighting language hint from the extension, or omitted for plain text. */
+  lang?: string
+}
+
+/**
+ * Whether `value` is a valid {@link FileTextLine} (defensive narrowing from
+ * opaque `meta`). `number` must be a 1-based integer line number, since a card
+ * rendered from a zero, fractional, or non-finite line number would violate the
+ * 1-based numbering contract the read window promises.
+ */
+function isFileTextLine(value: unknown): value is FileTextLine {
+  if (typeof value !== 'object' || value === null || Array.isArray(value)) return false
+  const { number, text } = value as Record<string, unknown>
+  return typeof number === 'number' && Number.isInteger(number) && number >= 1 && typeof text === 'string'
+}
+
+/**
+ * Narrow opaque live or replayed result metadata to a structured read window.
+ * Malformed metadata returns `undefined` so presentation can fall back to the
+ * generic text card instead of throwing during replay. Beyond shape, the
+ * semantic contract of a read window is enforced against replayed JSON that is
+ * well-typed but out of range: `offset` must be a 1-based integer, `totalLines`
+ * must be a non-negative integer, each line number must be a 1-based integer no
+ * less than `offset`, the line numbers must strictly increase, and no line number
+ * may exceed `totalLines`. Any violation declines to the generic fallback rather
+ * than emitting a card that misnumbers or overcounts.
+ * @param meta - result metadata.
+ * @returns the validated read window, or `undefined` for absent, malformed, or semantically invalid data.
+ */
+export function readMetaFromMeta(meta: unknown): FsReadMeta | undefined {
+  if (typeof meta !== 'object' || meta === null || Array.isArray(meta)) return undefined
+  const { path, offset, lines, totalLines, lang } = meta as Record<string, unknown>
+  if (typeof path !== 'string' || typeof totalLines !== 'number' || typeof offset !== 'number') return undefined
+  if (!Number.isInteger(offset) || offset < 1) return undefined
+  if (!Number.isInteger(totalLines) || totalLines < 0) return undefined
+  if (!Array.isArray(lines) || !lines.every(isFileTextLine)) return undefined
+  if (lang !== undefined && typeof lang !== 'string') return undefined
+  let previous = offset - 1
+  for (const { number } of lines) {
+    if (number <= previous || number > totalLines) return undefined
+    previous = number
+  }
+  return { path, offset, lines, totalLines, ...lang === undefined ? {} : { lang } }
+}
diff --git a/packages/fs/tool-fs/src/read.ts b/packages/fs/tool-fs/src/read.ts
index 05e1b41ae2..a92fdcaad8 100644
--- a/packages/fs/tool-fs/src/read.ts
+++ b/packages/fs/tool-fs/src/read.ts
@@ -6,11 +6,11 @@
 
 import type { Context } from 'cordis'
 import { defineTool } from '@deepseek-ai/dsh-tools'
-import type { GenericCallView, GenericResultView, ToolResult } from '@deepseek-ai/dsh-tools'
+import type { GenericCallView, ReadResultView, ToolResult } from '@deepseek-ai/dsh-tools'
 import { FsError } from '@deepseek-ai/dsh-fs'
 import type {} from '@deepseek-ai/dsh-fs'
 import type {} from '@deepseek-ai/dsh-system-prompt'
-import { buildWindow, formatReadOutput } from './read-render.ts'
+import { buildWindow, formatReadOutput, langFromPath, readMetaFromMeta } from './read-render.ts'
 import { sessionResolveOptions } from './session-cwd.ts'
 
 /** Default and maximum number of lines returned by one `read` call (the `readLimit` config). */
@@ -118,6 +118,19 @@ export function applyReadTool(ctx: Context, caps: ReadToolCaps): void {
           }),
         }]
       },
+      // Project the structured window into persisted `meta` so a UI's read card
+      // survives replay: the raw canonical output object is not on the wire, only
+      // the model-facing text, from which the line/lang data cannot be recovered.
+      presentationMeta: (_args, value) => {
+        const lang = langFromPath(value.path)
+        return {
+          path: value.path,
+          offset: value.offset,
+          lines: value.lines.map(({ number, text }) => ({ number, text })),
+          totalLines: value.totalLines,
+          ...lang === undefined ? {} : { lang },
+        }
+      },
     },
     // Observation races fail closed because guarded mutations re-check the version in-lock.
     isConcurrencySafe: () => true,
@@ -154,15 +167,32 @@ export function applyReadTool(ctx: Context, caps: ReadToolCaps): void {
       ctx.emit('fs/observed', target, info.version, exec)
       return outcome
     },
-    presentResult(_args, result: ToolResult): GenericResultView | undefined {
+    // Result-time display: a `read` card carrying the structured line window a
+    // capable UI renders as a line-numbered, syntax-highlighted view. The
+    // structured data is narrowed from the persisted `meta` (replay-safe); the
+    // envelope-stripped model-facing text rides along as `content` so a UI without
+    // the read capability still shows the file text. A malformed or absent meta,
+    // or a result whose text is not the read envelope, declines to `undefined`
+    // (the generic fallback), never throwing on replay of obsolete logged output.
+    presentResult(_args, result: ToolResult): ReadResultView | undefined {
       if (result.isError) return undefined
+      const meta = readMetaFromMeta(result.meta)
+      if (meta === undefined) return undefined
       const only = result.content.length === 1 ? result.content[0] : undefined
       const text = only?.type === 'text' ? only.text : undefined
       if (text === undefined) return undefined
       // Group 1 always captures (possibly empty) when the envelope matches.
       const body = /^<path>[^\n]*<\/path>\n<type>file<\/type>\n<content>\n([\s\S]*)\n<\/content>$/u.exec(text)?.[1]
       if (body === undefined) return undefined
-      return { card: 'generic', content: [{ type: 'text', text: body }] }
+      return {
+        card: 'read',
+        path: meta.path,
+        offset: meta.offset,
+        lines: meta.lines,
+        totalLines: meta.totalLines,
+        ...meta.lang === undefined ? {} : { lang: meta.lang },
+        content: [{ type: 'text', text: body }],
+      }
     },
     // Pure display: a generic card titled by the file with the read window appended (`Read
     // foo.txt (5 - 8)`), `read` kind (icon), and a follow-along location whose line is the
diff --git a/packages/fs/tool-fs/tests/read-render.spec.ts b/packages/fs/tool-fs/tests/read-render.spec.ts
index c2afaf002e..cc03a0c8f9 100644
--- a/packages/fs/tool-fs/tests/read-render.spec.ts
+++ b/packages/fs/tool-fs/tests/read-render.spec.ts
@@ -6,7 +6,7 @@
  */
 
 import { describe, expect, it } from 'vitest'
-import { buildWindow, READ_MAX_BYTES, READ_MAX_LINE_LENGTH } from '../src/read-render.ts'
+import { buildWindow, langFromPath, readMetaFromMeta, READ_MAX_BYTES, READ_MAX_LINE_LENGTH } from '../src/read-render.ts'
 import type { ReadWindow } from '../src/read-render.ts'
 
 const DEFAULT_CAPS = { maxLineLength: READ_MAX_LINE_LENGTH, maxBytes: READ_MAX_BYTES }
@@ -116,3 +116,103 @@ describe('buildWindow', () => {
     })
   })
 })
+
+describe('langFromPath', () => {
+  it('maps a known extension to its language hint, case-insensitively', () => {
+    expect(langFromPath('src/a.ts')).toBe('ts')
+    expect(langFromPath('src/a.TSX')).toBe('tsx')
+    expect(langFromPath('/abs/module.mjs')).toBe('js')
+    expect(langFromPath('conf.yml')).toBe('yaml')
+    expect(langFromPath('README.md')).toBe('md')
+  })
+
+  it('reads the extension after the last path segment and last dot', () => {
+    expect(langFromPath('a.py.bak')).toBeUndefined()
+    expect(langFromPath('archive.tar.gz')).toBeUndefined()
+    expect(langFromPath('/dir.py/plain')).toBeUndefined()
+    expect(langFromPath('C:\\src\\main.rs')).toBe('rs')
+  })
+
+  it('returns undefined for a dotfile, an extensionless name, and an unknown extension', () => {
+    expect(langFromPath('.gitignore')).toBeUndefined()
+    expect(langFromPath('/etc/hosts')).toBeUndefined()
+    expect(langFromPath('data.unknownext')).toBeUndefined()
+    expect(langFromPath('trailingdot.')).toBeUndefined()
+  })
+
+  it('returns undefined for a filename whose extension is an Object.prototype key', () => {
+    // Own-property lookup only: these must not resolve to the inherited member
+    // (a function/object), which would fail the tool-output JSON validation.
+    expect(langFromPath('foo.constructor')).toBeUndefined()
+    expect(langFromPath('foo.__proto__')).toBeUndefined()
+    expect(langFromPath('foo.toString')).toBeUndefined()
+    expect(langFromPath('foo.hasOwnProperty')).toBeUndefined()
+  })
+})
+
+describe('readMetaFromMeta', () => {
+  const good = { path: '/abs/a.ts', offset: 1, lines: [{ number: 1, text: 'x' }], totalLines: 1, lang: 'ts' }
+
+  it('narrows a well-formed read meta, with and without a lang hint', () => {
+    expect(readMetaFromMeta(good)).toEqual(good)
+    const noLang = { path: '/abs/a', offset: 1, lines: [], totalLines: 0 }
+    expect(readMetaFromMeta(noLang)).toEqual(noLang)
+  })
+
+  it('narrows an empty window at a positive offset (byte cap below the first selected line)', () => {
+    const empty = { path: '/abs/a', offset: 5, lines: [], totalLines: 9 }
+    expect(readMetaFromMeta(empty)).toEqual(empty)
+  })
+
+  it('returns undefined for absent, non-object, or array meta', () => {
+    expect(readMetaFromMeta(undefined)).toBeUndefined()
+    expect(readMetaFromMeta(null)).toBeUndefined()
+    expect(readMetaFromMeta('nope')).toBeUndefined()
+    expect(readMetaFromMeta([good])).toBeUndefined()
+  })
+
+  it('returns undefined when a field is missing or the wrong type (defensive narrowing)', () => {
+    expect(readMetaFromMeta({ ...good, path: 5 })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, offset: '1' })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, totalLines: '1' })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, lines: 'nope' })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, lines: [{ number: '1', text: 'x' }] })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, lines: [{ number: 1 }] })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, lines: [null] })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, lang: 5 })).toBeUndefined()
+  })
+
+  it('rejects an offset that is not a 1-based integer', () => {
+    expect(readMetaFromMeta({ ...good, offset: 0 })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, offset: 1.5 })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, offset: NaN })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, offset: Infinity })).toBeUndefined()
+  })
+
+  it('rejects a first line number below offset', () => {
+    expect(readMetaFromMeta({ ...good, offset: 2, lines: [{ number: 1, text: 'x' }], totalLines: 2 })).toBeUndefined()
+  })
+
+  it('rejects a line number that is not a 1-based integer', () => {
+    expect(readMetaFromMeta({ ...good, lines: [{ number: 0, text: 'x' }], totalLines: 1 })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, lines: [{ number: 1.5, text: 'x' }], totalLines: 2 })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, lines: [{ number: NaN, text: 'x' }], totalLines: 1 })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, lines: [{ number: Infinity, text: 'x' }], totalLines: 1 })).toBeUndefined()
+  })
+
+  it('rejects a totalLines that is not a non-negative integer', () => {
+    expect(readMetaFromMeta({ ...good, totalLines: -1 })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, totalLines: 1.5 })).toBeUndefined()
+    expect(readMetaFromMeta({ ...good, totalLines: NaN })).toBeUndefined()
+  })
+
+  it('rejects lines that do not strictly increase or exceed totalLines', () => {
+    const twoLines = { path: '/abs/a', offset: 1, lang: 'ts' }
+    // Duplicate line numbers.
+    expect(readMetaFromMeta({ ...twoLines, lines: [{ number: 1, text: 'a' }, { number: 1, text: 'b' }], totalLines: 2 })).toBeUndefined()
+    // Out-of-order line numbers.
+    expect(readMetaFromMeta({ ...twoLines, lines: [{ number: 2, text: 'b' }, { number: 1, text: 'a' }], totalLines: 2 })).toBeUndefined()
+    // A line number past totalLines.
+    expect(readMetaFromMeta({ ...twoLines, lines: [{ number: 3, text: 'c' }], totalLines: 2 })).toBeUndefined()
+  })
+})
diff --git a/packages/fs/tool-fs/tests/tools.spec.ts b/packages/fs/tool-fs/tests/tools.spec.ts
index de844dcaf4..914a1bf7de 100644
--- a/packages/fs/tool-fs/tests/tools.spec.ts
+++ b/packages/fs/tool-fs/tests/tools.spec.ts
@@ -320,6 +320,39 @@ describe('read tool', () => {
     expect(text(result)).toContain('Output capped.')
   })
 
+  it('attaches the structured window as presentation meta, and presentResult narrows it into a read card', async () => {
+    const { ctx, fs } = await setup()
+    fs.files.set('key:a.ts', 'const x = 1\nconst y = 2')
+    const result = await call(ctx, 'read', { file_path: 'a.ts' })
+    expect(result.isError).toBe(false)
+    if (result.isError) throw new Error('expected read success')
+    // The extension drives the lang hint; the window rides on persisted meta.
+    expect(result.meta).toEqual({
+      path: '/abs/a.ts',
+      offset: 1,
+      lines: [{ number: 1, text: 'const x = 1' }, { number: 2, text: 'const y = 2' }],
+      totalLines: 2,
+      lang: 'ts',
+    })
+    const view = ctx.tools.get('read')?.presentResult?.({ file_path: 'a.ts' }, result)
+    expect(view).toEqual({
+      card: 'read',
+      path: '/abs/a.ts',
+      offset: 1,
+      lines: [{ number: 1, text: 'const x = 1' }, { number: 2, text: 'const y = 2' }],
+      totalLines: 2,
+      lang: 'ts',
+      content: [{ type: 'text', text: '1: const x = 1\n2: const y = 2\n\n(End of file - total 2 lines)' }],
+    })
+  })
+
+  it('omits the lang hint in meta for an extension that maps to no language', async () => {
+    const { ctx, fs } = await setup()
+    fs.files.set('key:notes', 'plain')
+    const result = await call(ctx, 'read', { file_path: 'notes' })
+    if (result.isError) throw new Error('expected read success')
+    expect(result.meta).toEqual({ path: '/abs/notes', offset: 1, lines: [{ number: 1, text: 'plain' }], totalLines: 1 })
+  })
 })
 
 describe('formatReadOutput footer variants', () => {
@@ -450,33 +483,72 @@ describe('tool-owned presentation (pure presentCall)', () => {
     })
   })
 
-  it('read: completed presentation removes the model-facing XML envelope', async () => {
-    expect(await presentResult('read', { file_path: 'a.txt' }, {
-      content: [{ type: 'text', text: '<path>/tmp/a.txt</path>\n<type>file</type>\n<content>\n1: hello\n\n(End of file - total 1 lines)\n</content>' }],
+  it('read: completed presentation is a read card carrying the structured window with the envelope stripped', async () => {
+    // The structured line data rides on persisted meta (the raw output object is
+    // not on the wire); presentResult narrows it and appends the stripped text as
+    // the no-capability `content` fallback.
+    const meta = { path: '/tmp/a.ts', offset: 1, lines: [{ number: 1, text: 'hello' }], totalLines: 1, lang: 'ts' }
+    expect(await presentResult('read', { file_path: 'a.ts' }, {
+      content: [{ type: 'text', text: '<path>/tmp/a.ts</path>\n<type>file</type>\n<content>\n1: hello\n\n(End of file - total 1 lines)\n</content>' }],
       isError: false,
+      meta,
     })).toEqual({
-      card: 'generic',
+      card: 'read',
+      path: '/tmp/a.ts',
+      offset: 1,
+      lines: [{ number: 1, text: 'hello' }],
+      totalLines: 1,
+      lang: 'ts',
       content: [{ type: 'text', text: '1: hello\n\n(End of file - total 1 lines)' }],
     })
-    expect(await presentResult('read', { file_path: 'a.txt' }, {
+    // A window whose extension maps to no language omits `lang` from the card.
+    expect(await presentResult('read', { file_path: 'notes' }, {
+      content: [{ type: 'text', text: '<path>/tmp/notes</path>\n<type>file</type>\n<content>\nbody\n</content>' }],
+      isError: false,
+      meta: { path: '/tmp/notes', offset: 1, lines: [{ number: 1, text: 'body' }], totalLines: 1 },
+    })).toEqual({
+      card: 'read',
+      path: '/tmp/notes',
+      offset: 1,
+      lines: [{ number: 1, text: 'body' }],
+      totalLines: 1,
+      content: [{ type: 'text', text: 'body' }],
+    })
+    // Malformed envelope text with valid meta still declines (the fallback text is unavailable).
+    expect(await presentResult('read', { file_path: 'a.ts' }, {
       content: [{ type: 'text', text: 'malformed replay' }],
       isError: false,
+      meta,
+    })).toBeUndefined()
+    // Valid envelope but absent/malformed meta declines to the generic fallback.
+    expect(await presentResult('read', { file_path: 'a.ts' }, {
+      content: [{ type: 'text', text: '<path>/tmp/a.ts</path>\n<type>file</type>\n<content>\n1: hello\n</content>' }],
+      isError: false,
+    })).toBeUndefined()
+    expect(await presentResult('read', { file_path: 'a.ts' }, {
+      content: [{ type: 'text', text: '<path>/tmp/a.ts</path>\n<type>file</type>\n<content>\n1: hello\n</content>' }],
+      isError: false,
+      meta: { path: '/tmp/a.ts', lines: 'nope', totalLines: 1 },
     })).toBeUndefined()
   })
 
   it('read: completed presentation declines errors and non-single-text content', async () => {
     const envelope = '<path>/tmp/a.txt</path>\n<type>file</type>\n<content>\nbody\n</content>'
+    const meta = { path: '/tmp/a.txt', offset: 1, lines: [{ number: 1, text: 'body' }], totalLines: 1 }
     expect(await presentResult('read', { file_path: 'a.txt' }, {
       content: [{ type: 'text', text: envelope }],
       isError: true,
+      meta,
     })).toBeUndefined()
     expect(await presentResult('read', { file_path: 'a.txt' }, {
       content: [{ type: 'text', text: envelope }, { type: 'text', text: 'second' }],
       isError: false,
+      meta,
     })).toBeUndefined()
     expect(await presentResult('read', { file_path: 'a.txt' }, {
       content: [{ type: 'reasoning', text: envelope }],
       isError: false,
+      meta,
     })).toBeUndefined()
   })
 
diff --git a/packages/ui/tui/src/components/transcript.ts b/packages/ui/tui/src/components/transcript.ts
index 8491b98733..c991e85c1f 100644
--- a/packages/ui/tui/src/components/transcript.ts
+++ b/packages/ui/tui/src/components/transcript.ts
@@ -402,12 +402,15 @@ export class ToolCardComponent implements Component {
     const glyph = this.result === undefined ? '○' : '●'
     const rawBody = this.renderBody()
     const view = this.resultView ?? this.callView
-    // A generic card's own content, or a web card's fallback to the raw result
-    // content (the `web` view carries no `content` copy), both render as one dim
-    // Markdown block below, so links/lists/headings keep the unified dim styling
-    // rather than reading as bare text. Terminal and diff cards own their body
-    // styling, so they are excluded (mirrors renderBody's post-terminal/diff fallback).
-    const markdownContent = view.card === 'generic'
+    // A generic card's own content, or a read card's `content` fallback (the
+    // envelope-stripped file text — the TUI has no dedicated read rendering, so a
+    // read renders exactly as before the read card existed), or a web card's
+    // fallback to the raw result content (the `web` view carries no `content`
+    // copy), all render as one dim Markdown block below, so links/lists/headings
+    // keep the unified dim styling rather than reading as bare text. Terminal and
+    // diff cards own their body styling, so they are excluded (mirrors
+    // renderBody's post-terminal/diff fallback).
+    const markdownContent = view.card === 'generic' || view.card === 'read'
       ? view.content ?? this.result?.content
       : view.card === 'web'
         // A web resultView is only assigned alongside this.result (the result
@@ -532,11 +535,12 @@ export class ToolCardComponent implements Component {
       // rather than under the dim result-output color.
       return { prelude: [...hunks, footer], lines: [] }
     }
-    // The web card carries no `content` copy, so a `web` result view falls back
-    // to the raw result content here (`view.card === 'generic'` narrows the
-    // generic union arm; a `web` card takes the same fallback, mirroring the
-    // `markdownContent` selection in render()).
-    const content = (view.card === 'generic' ? view.content : undefined) ?? this.result?.content
+    // A generic or read card carries its own envelope-stripped `content`; a `web`
+    // card carries no `content` copy and falls back to the raw result content
+    // here. (Mirrors the `markdownContent` selection in render(); a read card has
+    // no dedicated TUI rendering, so its `content` takes the same body path,
+    // keeping read output as it was before the read card existed.)
+    const content = (view.card === 'generic' || view.card === 'read' ? view.content : undefined) ?? this.result?.content
     const prelude: string[] = []
     const lines: string[] = []
     // The presenter title headlines the body now that the header is a fixed