Merge remote-tracking branch 'origin/master' into worktree/pr576-merge-master-20260723

.agents/notes/implemented/feature/2026-07-21-log-backed-session-titles.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write
-2026-07-21-log-backed-session-titles.md: cd0d2a4bab9b6504c65e942c0e03bce79488364e
-2026-07-21-log-backed-session-titles.zh.md: b90ac6c59677e6542733210b91de38ef1169c760
+2026-07-21-log-backed-session-titles.md: 183aa6909fecffdaf18c77c2a66fbc38c67c2d2c
+2026-07-21-log-backed-session-titles.zh.md: c6a0c2ce2ad4b2cddec2ada36f655fe55adb143b

.agents/notes/implemented/feature/2026-07-21-log-backed-session-titles.md

@@ -12,7 +12,7 @@ Session identity metadata is immutable, the event log is the replay and fork bou
 
 ## Decision
 
-The [`session-title` capability family](../../../../packages/session-title/README.md) owns title state and generation policy. `@deepseek-ai/dsh-session-title` provides `ctx.sessionTitle`, a deterministic first-message fallback, and a registry for at most one optional asynchronous provider. `@deepseek-ai/dsh-session-title-llm` owns the common auxiliary-model request policy; separate first-message and all-user-messages plugins choose input cadence. The shared agent spine mounts only the fallback service with overridable explicit example limits, leaving both model providers opt-in.
+The [`session-title` capability family](../../../../packages/session-title/README.md) owns title state and generation policy. `@deepseek-ai/dsh-session-title` provides `ctx.sessionTitle`, a deterministic first-message fallback, and a registry for at most one optional asynchronous provider. `@deepseek-ai/dsh-session-title-llm` owns the common auxiliary-model request policy; separate first-message and all-user-messages plugins choose input cadence. The shared agent spine mounts only the fallback service. The Web host mounts that service plus the first-message model provider with explicit overridable limits, so a fresh Web session gains an immediate fallback and then a non-blocking model summary. Other compositions choose either model provider explicitly.
 
 ### Event ownership and folding
 
@@ -32,7 +32,7 @@ The first-message provider schedules once when a fresh session first creates its
 
 `register(provider)` validates one branded stable id, cadence, and generation function, then returns an awaitable effect disposer. A second live registration throws immediately. Provider disposal marks the registration closing, aborts its pending and active work, and waits for every call to settle before removing the registration, so replacement cannot overlap a provider that ignores cancellation. Session disposal aborts its active work. Service teardown prevents queued fallback and provider microtasks from starting, aborts active work, and drains tracked promises before unloading completes. Every session-local generation has a monotonic revision and exact registration identity; acceptance rechecks revision, registration, session liveness, service liveness, and cancellation, so stale output cannot commit.
 
-Model providers require explicit word, CJK-character, input-byte, output-token, and timeout limits. Optional `provider` and `model` overrides are a pair; without them the helper uses the exact route from the logged main request header. Selected messages are framed as JSON under one fixed language-aware instruction. The input limit measures that final user prompt, including wrappers, seq fields, and JSON escaping, before the request is logged or dispatched. Oversized input is rejected rather than truncated because truncation would make the recorded source seqs falsely imply complete use. The fused deadline is checked while consuming each stream chunk and after completion, so a successful result returned after timeout cannot be accepted even when an interceptor or adapter ignores abort.
+Model providers require explicit word, CJK-character, input-byte, output-token, and timeout limits. Optional `provider` and `model` overrides are a pair; without them the helper uses the exact route from the logged main request header. Selected messages are framed as JSON under one fixed language-aware instruction. The dispatched `GenerateOptions` carries `purpose: 'session-title'`; the DeepSeek adapter maps that purpose to thinking-disabled and omits reasoning effort so the bounded output is visible title text, while the main conversation keeps its configured thinking mode. The input limit measures the final user prompt, including wrappers, seq fields, and JSON escaping, before the request is logged or dispatched. Oversized input is rejected rather than truncated because truncation would make the recorded source seqs falsely imply complete use. The fused deadline is checked while consuming each stream chunk and after completion, so a successful result returned after timeout cannot be accepted even when an interceptor or adapter ignores abort.
 
 Automatic provider failures are nonfatal warnings and retain the latest title. Explicit refresh failures reject to the caller. Output must be non-empty text with unique ordered seqs drawn from the fixed request; the service normalizes and byte-limits it before durable acceptance.
 
@@ -40,7 +40,7 @@ Automatic provider failures are nonfatal warnings and retain the latest title. E
 
 A fork inherits seed title events unchanged, like the rest of its source log. The first-message provider does not automatically retitle a fork. The all-messages provider may append a child-owned revision after a later child prompt, using inherited and new eligible messages.
 
-`ctx.sessionQuery.readTitle()` folds one live-preferred or persisted log without loading titles during `listSessions()`. ACP maps the event to `session_info_update` during both live streaming and load replay, using the event timestamp for `updatedAt`. The TUI uses the latest title as its header subtitle and sets the terminal window title to `<session title> — <configured product title>` after terminal-safe rendering. A synthetic title turn remains a completed durability boundary for the metadata write; consumers reporting agent completion use the core `findLastMessageTurnEnd()` fold so a later title, injection, or other plugin-owned turn cannot replace the preceding message-triggered outcome.
+`ctx.sessionQuery.readTitle()` folds one live-preferred or persisted log without loading titles during `listSessions()`. ACP maps the event to `session_info_update` during both live streaming and load replay, using the event timestamp for `updatedAt`. The TUI uses the latest title as its header subtitle and sets the terminal window title to `<session title> — <configured product title>` after terminal-safe rendering. The Web host folds the same log state into a validated mux control frame after each attached-session subscription baseline and immediately after forwarding a live raw title event. The browser retains only newer title event seqs even when the control frame precedes list or session-instance creation; sidebar labels, search, breadcrumbs, and the browser title then react to the projected revision. `session.list` remains metadata-only, so a cold persisted session uses the cwd basename or id until opening or resuming it attaches the log. The browser title uses `<session title> — <existing HTML title>` only for a selected titled session and otherwise preserves the product title. A synthetic title turn remains a completed durability boundary for the metadata write; consumers reporting agent completion use the core `findLastMessageTurnEnd()` fold so a later title, injection, or other plugin-owned turn cannot replace the preceding message-triggered outcome.
 
 ## Alternatives considered
 
@@ -50,11 +50,13 @@ A fork inherits seed title events unchanged, like the rest of its source log. Th
 - **Permit multiple registered providers and resolve precedence after completion** — rejected because completion order is not product precedence and would make retries, HMR, and provenance nondeterministic. A deployment that needs a composite policy can register one provider that owns that policy.
 - **Silently truncate oversized auxiliary input** — rejected because the provider result would claim exact source-message provenance while receiving only partial text. Keeping the prior title and warning preserves truthful attribution.
 - **Index titles in `listSessions()` immediately** — rejected because the existing lightweight metadata list would need per-backend derived-index synchronization. Exact `readTitle()` establishes the read contract without precommitting search or indexing policy.
+- **Keep the Web host fallback-only** — rejected because the UI would expose durable titles but never improve them beyond the first-prompt prefix. The first-message provider keeps its latency off the main response path while making model summaries the default Web outcome.
 
 ## Consequences
 
 - Titles survive JSONL and SQLite persistence, replay through ACP, and follow fork inheritance without a separate mutable record.
-- A fallback appears without an auxiliary call; deployments choose whether better titles justify model cost and whether later prompts should retitle a session.
+- Web title delivery stays incremental and log-backed without a title index or persisted-list scan; cold list rows improve after attach.
+- A fallback appears immediately. Each fresh Web session adds one first-message auxiliary call; other compositions choose whether better titles justify model cost and whether later prompts should retitle a session.
 - Auxiliary request records and late accepted titles consume event seqs and may create balanced zero-step turns, so persistence exposes both attempted dispatches and accepted updates even though model history and KV-cache identity do not change.
 - One provider and monotonic per-session revisions make disposal, supersession, and stale-result rejection explicit, at the cost of leaving multi-strategy precedence to a composite provider.
 - Manual rename, deletion, generated-versus-user precedence, search, and list indexing remain outside the capability.

.agents/notes/implemented/feature/2026-07-21-log-backed-session-titles.zh.md

@@ -12,7 +12,7 @@ Status: implemented
 
 ## 决策
 
-[`session-title` 功能包族](../../../../packages/session-title/README.md)负责标题状态和生成策略。`@deepseek-ai/dsh-session-title` 提供 `ctx.sessionTitle`、确定性的首消息回退方案，以及一个至多接受单个可选异步提供方的注册表。`@deepseek-ai/dsh-session-title-llm` 负责通用的辅助模型请求策略；首消息插件和全部用户消息插件分别选择输入调度方式。共享 agent 主干只挂载回退服务，并为其显式设置可覆盖的示例限制；两种模型提供方均需按需启用。
+[`session-title` 功能包族](../../../../packages/session-title/README.md)负责标题状态和生成策略。`@deepseek-ai/dsh-session-title` 提供 `ctx.sessionTitle`、确定性的首消息回退方案，以及一个至多接受单个可选异步提供方的注册表。`@deepseek-ai/dsh-session-title-llm` 负责通用的辅助模型请求策略；首消息插件和全部用户消息插件分别选择输入调度方式。共享 agent 主干只挂载回退服务。Web host 会挂载该服务和首消息模型提供方，并显式设置可覆盖的限制，因此新建的 Web 会话会立即获得回退标题，随后在不阻塞主响应的情况下获得模型摘要。其他组合需显式选择任一模型提供方。
 
 ### 事件归属与折叠
 
@@ -32,7 +32,7 @@ Status: implemented
 
 `register(provider)` 会验证一个带品牌类型的稳定 id、执行时机和生成函数，然后返回一个可等待完成的 effect 资源释放函数。第二个活跃注册会立即抛出错误。提供方执行资源释放时，会将注册标记为正在关闭，中止其待执行和活跃工作，并等待所有调用结束后才移除注册，因此替代提供方不会与忽略取消的旧提供方重叠运行。会话资源释放会中止其活跃工作。服务卸载时，会阻止排队中的回退和提供方微任务启动，中止活跃工作，并且卸载完成前会等待所有已跟踪的 promise 结算。每项会话本地生成都有单调递增的修订号和对应的注册身份；接受结果时会重新检查修订号、注册、会话活跃状态、服务活跃状态和取消状态，因此陈旧输出无法提交。
 
-模型提供方必须显式配置单词数、CJK 字符数、输入字节数、输出 token 数和超时限制。可选的 `provider` 和 `model` 覆盖项必须成对提供；两者均未提供时，辅助组件会使用主请求已记录请求头中的准确路由。系统在一条固定且能区分语言的指令下，将选中的消息封装为 JSON。输入字节数按最终形成的用户提示词计算，其中包括包装文本、seq 字段和 JSON 转义；系统会在记录请求或发起调用前完成这项检查。过大输入会被拒绝而不是截断，因为截断会让记录的源消息 seq 错误地表示这些消息已被完整使用。系统在消费每个流分片时以及流完成后都会检查融合后的截止时间，因此即使拦截器或适配器忽略中止信号，超时后返回的成功结果也不会被接受。
+模型提供方必须显式配置单词数、CJK 字符数、输入字节数、输出 token 数和超时限制。可选的 `provider` 和 `model` 覆盖项必须成对提供；两者均未提供时，辅助组件会使用主请求已记录请求头中的准确路由。系统在一条固定且能区分语言的指令下，将选中的消息封装为 JSON。发出的 `GenerateOptions` 携带 `purpose: 'session-title'`；DeepSeek 适配器将该用途映射为禁用思考且省略推理强度设置的请求，使受限输出成为可见的标题文本，而主对话仍沿用已配置的思考模式。输入字节数按最终形成的用户提示词计算，其中包括包装文本、seq 字段和 JSON 转义；系统会在记录请求或发起调用前完成这项检查。过大输入会被拒绝而不是截断，因为截断会让记录的源消息 seq 错误地表示这些消息已被完整使用。系统在消费每个流分片时以及流完成后都会检查融合后的截止时间，因此即使拦截器或适配器忽略中止信号，超时后返回的成功结果也不会被接受。
 
 自动提供方故障只会发出非致命警告，并保留最新标题。显式刷新失败则会向调用方返回拒绝。输出必须是非空文本，并包含来自固定请求、唯一且有序的 seq；服务会在持久接受前对其进行规范化并施加字节限制。
 
@@ -40,7 +40,7 @@ Status: implemented
 
 与源日志的其他部分相同，fork 会原样继承作为种子的标题事件。首消息提供方不会自动为 fork 重新生成标题。全部消息提供方可以在子会话出现后续提示词后追加一项归子会话所有的修订，并使用继承的合格消息和新增的合格消息。
 
-`ctx.sessionQuery.readTitle()` 会折叠一份实时优先或已持久化的日志，而不会在 `listSessions()` 期间加载标题。ACP（Agent Client Protocol）会在实时流式输出和加载回放期间把该事件映射到 `session_info_update`，并使用事件时间戳作为 `updatedAt`。TUI 使用最新标题作为其标题栏副标题，并在完成终端安全渲染后，将终端窗口标题设置为 `<session title> — <configured product title>`。合成标题轮次本身仍会完成，并作为元数据写入的持久性边界；报告 agent 完成情况的消费方使用核心的 `findLastMessageTurnEnd()` 折叠逻辑，因此后续的标题轮次、注入轮次或其他归插件所有的轮次无法取代此前由消息触发的结果。
+`ctx.sessionQuery.readTitle()` 会折叠一份实时优先或已持久化的日志，而不会在 `listSessions()` 期间加载标题。ACP（Agent Client Protocol）会在实时流式输出和加载回放期间把该事件映射到 `session_info_update`，并使用事件时间戳作为 `updatedAt`。TUI 使用最新标题作为其标题栏副标题，并在完成终端安全渲染后，将终端窗口标题设置为 `<session title> — <configured product title>`。Web host 会在每个已附加会话的订阅基线之后，以及转发实时原始标题事件后立即，将同一份日志状态折叠为经过校验的 mux 控制帧。即使控制帧先于列表或会话实例创建抵达，浏览器也只保留标题事件 seq 较新的版本；侧边栏标签、搜索、面包屑和浏览器标题会随投影后的修订更新。`session.list` 仍只包含元数据，因此尚未打开的持久化会话会继续以 cwd 基名或 id 作为回退，直至打开或恢复会话时附加其日志。浏览器仅在选中已有标题的会话时将标题设置为 `<session title> — <existing HTML title>`，否则保留产品标题。合成标题轮次本身仍会完成，并作为元数据写入的持久性边界；报告 agent 完成情况的消费方使用核心的 `findLastMessageTurnEnd()` 折叠逻辑，因此后续的标题轮次、注入轮次或其他归插件所有的轮次无法取代此前由消息触发的结果。
 
 ## 考虑过的替代方案
 
@@ -50,11 +50,13 @@ Status: implemented
 - **允许注册多个提供方，并在完成后解析优先级**：不予采纳，因为完成顺序并不等于产品优先级，而且会让重试、HMR 和来源信息变得不确定。需要组合策略的部署可以注册一个自行负责该策略的提供方。
 - **静默截断过大的辅助输入**：不予采纳，因为提供方结果会声明准确的源消息来源信息，实际却只接收了部分文本。保留原有标题并发出警告，可以保持归因真实。
 - **立即在 `listSessions()` 中索引标题**：不予采纳，因为现有的轻量元数据列表将需要逐后端同步派生索引。精确的 `readTitle()` 建立了读取契约，而没有提前锁定搜索或索引策略。
+- **让 Web host 只使用回退标题**：不予采纳，因为 UI 虽会显示持久标题，却始终无法将第一条提示词的前缀改进为更好的标题。首消息提供方在主响应路径之外运行，并让模型摘要成为 Web 的默认结果。
 
 ## 后果
 
 - 标题可以在 JSONL 和 SQLite 持久化中存续，通过 ACP 回放，并遵循 fork 继承语义，而无需单独的可变记录。
-- 回退标题无需辅助调用即可出现；部署方可以自行决定更优标题是否值得模型成本，以及后续提示词是否需要重新生成会话标题。
+- Web 标题仍以增量方式从日志交付，无需标题索引或扫描持久化列表；冷启动列表项会在会话附加后改用标题。
+- 回退标题会立即出现。每个新建的 Web 会话都会增加一次针对首消息的辅助调用；其他组合可以自行决定更优标题是否值得模型成本，以及后续提示词是否需要重新生成会话标题。
 - 辅助请求记录和延迟接受的标题会占用事件 seq，并可能创建平衡的零步骤轮次，因此持久化会同时呈现尝试发起的调用与已接受的更新，尽管模型历史和 KV 缓存标识保持不变。
 - 单个提供方和每会话单调递增的修订号让释放、取代和陈旧结果拒绝行为明确可见，但多策略优先级必须由复合提供方负责。
 - 手动重命名、删除、生成标题与用户标题的优先级、搜索和列表索引不在此功能范围内。

.agents/notes/implemented/process/2026-07-20-gui-testing-system.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write
-2026-07-20-gui-testing-system.md: fdd5c7f9d33f9a90ea4afe145265be5fe93e0fc2
-2026-07-20-gui-testing-system.zh.md: 0ae08133742711b87e9155ddc6f3104b757c1b55
+2026-07-20-gui-testing-system.md: e42dafcdf37e48475e7d420eaad9600e6c20891c
+2026-07-20-gui-testing-system.zh.md: e4ef6246e59e0ad6c0a3070a38c546f964e347fa

.agents/notes/implemented/process/2026-07-20-gui-testing-system.md

@@ -19,24 +19,24 @@ Cut along the architecture's natural test seams into three tiers, bottom-up:
 | Tier | Under test | Key technique | File location |
 |---|---|---|---|
 | 1 Protocol isomorphism | `AbstractApiClient` + `toFetchHandler` (bidirectional data / rpcId / zod types / SSE streams / batching / timeouts) | **The full chain at the isomorphic point**: `InProcessApiClient(toFetchHandler(脚本化 impl))` skips the network but genuinely runs the wire serialization — zero browser, pure node env | `packages/host/apiproxy/tests/client-handler.spec.ts` |
-| 2 Object-layer orchestration | `Session`/`SessionManager`/`ConnectionController` (state machines and timing: stitching / dedup / paging / optimistic draft clearing / pendingBuffers / reconnect / backoff) | **The "event sequence in → snapshot out" golden path**: programmable fakes + deferreds controlling timing + fake timers controlling backoff | `packages/client/web-runtime/tests/{session,manager,connection,…}.spec.ts` |
-| 3 Browser smoke | Build artifacts × a real browser (the page boots, one conversation round-trips) | Bare playwright library (chromium headless, no @playwright/test framework), minimal pass-through; fixture level + real-host level (self-skips without a key) | `apps/web/tests/smoke-{fixture,real}.e2e.ts` |
+| 2 Object-layer orchestration | `Session`/`SessionManager`/`ConnectionController` (state machines and timing: stitching / dedup / paging / optimistic draft clearing / pendingBuffers / reconnect / backoff) | **The "event sequence in → snapshot out" golden path**: programmable fakes + deferreds controlling timing + fake timers controlling backoff | `packages/client/{runtime,connection}/tests/` |
+| 3 Assembled presentation | Built artifacts × the real client loader and plugin composition | App-owned semantic snapshots boot all eight built client plugins under jsdom for deterministic cross-plugin state changes; bare Playwright smoke separately proves the real browser/carrier boundary, with real-host cases self-skipping without a key | `apps/web/tests/*.snapshot.ts`, `apps/web/tests/smoke-{fixture,real}.e2e.ts` |
 
-Inter-tier discipline: **each tier tests its own layer, upper tiers never re-test lower ones** — smoke only proves the wiring is alive (the fixture level asserts zero `/api` requests and zero pageerror), interaction detail belongs to the verify scripts (see the lane map), wire semantics to tier 1, data semantics to tier 2. Pure-function layers (lineage/partial/notifier/fold-adapter) are tested directly with zero fakes in the same package's tests/ alongside tier 2.
+Inter-tier discipline: **each tier tests its own layer, upper tiers never re-test lower ones** — an app semantic snapshot pins only user-visible projection across the assembled plugin boundary, while Playwright smoke proves browser and carrier liveness; wire semantics belong to tier 1 and data semantics to tier 2. Pure-function layers (lineage/partial/notifier/fold-adapter) are tested directly with zero fakes in the same package's tests/ alongside tier 2.
 
-- **Host side** (apiproxy/runtime/webserver): under the repo-wide `test:coverage` gate, per-file 100%.
-- **Client side**: web-runtime **is already under the per-file 100% gate** (12 defensive unreachable arms carry reasoned `/* v8 ignore */` comments); the `vitest.config.ts` coverage.exclude is down to `packages/client/web-ui/src/**` (temporary — lifted progressively as component specs fill in after the component redo); tests still run, the exclusion only keeps web-ui src out of the thresholds. web-ui takes the **jsdom route (landed)**: jsdom + @testing-library/react entered root devDependencies (dev-only), first spec `web-ui/tests/utils.spec.tsx` (utils pure functions + component RTL render + hook uSES probe); the environment uses the per-file `// @vitest-environment jsdom` pragma, zero impact on the other node-env packages.
-- The exclusion is an **explicitly annotated ruling**, not a silent waiver; the lift path = delete the exclude line + add a justified exclusion or the missing tests.
+- **Host and client source** are under the repo-wide per-file 100% coverage gate except the narrow browser-grade exclusions annotated in `vitest.config.ts`; component suites use per-file jsdom pragmas and Testing Library without changing Node suites.
+- **App-owned semantic snapshots** read built client bundles, execute them through the real loader, and drive only deterministic fixture hooks. They own stable visible state such as sidebar labels, breadcrumbs, and `document.title`, not CSS pixels or lower-layer state-machine details.
 
 ## Lane map
 
 | Scenario | Command | Content | When to run |
 |---|---|---|---|
 | Baseline | `pnpm run test:gui` | Tier 1+2 vitest (`packages/client packages/host`), seconds-fast, no browser, no server | Casually, after touching any GUI source |
+| Semantic snapshot | `DSH_EXAMPLE_MODE=lib pnpm run test:snapshot` | Keyless assembled-application semantics plus the repo's transport-specific expected outputs | After a human-visible GUI change; before delivery |
 | Browser end-to-end | `pnpm run test:web` | Rebuilds the front-end dist first, then runs the tier-3 two-level smoke (fixture level + real-host level self-skip) | After touching the build surface/boot/carriage; before delivery |
-| Gate | `pnpm run test:coverage` | The repo-wide gate (host-side GUI packages included, client side excluded) | The PR window |
+| Gate | `pnpm run test:coverage` | The repo-wide gate (host and client GUI packages included, except annotated browser-grade exclusions) | The PR window |
 
-**Division of labor between the verify scripts and vitest**: verify owns browser black-box regression (sequential steps = a user-operation script, one shared browser session, streaming PASS/FAIL output for the agent to locate the break), vitest owns first-class data-layer semantic assertions (reference stability `toBe`, state-machine timing, wire shapes). The two lanes complement each other, neither absorbs the other — scripts do not migrate to vitest (tearing apart an ordered script is a net loss); promoting one means wrapping a spawn shell hooked into the e2e lane, never rewriting the script body.
+**Division of labor between the browser scripts and vitest**: Playwright owns browser/carrier black-box regression and long sequential user journeys; ordinary vitest owns data-layer semantics such as reference stability, timing, and wire shapes; snapshot vitest owns stable app-level semantic output through the built composition. These lanes complement each other rather than duplicating assertions.
 
 ## Anti-regression discipline
 
@@ -46,7 +46,7 @@ Inter-tier discipline: **each tier tests its own layer, upper tiers never re-tes
 
 ## Consequences
 
-Each lane tests its own tier: touching any GUI source gets seconds-fast `test:gui` feedback, wire/object-layer semantics assert in milliseconds in node env, and the browser carries only wiring-liveness smoke. On the gate surface, the host side is fully under per-file 100%; on the client side web-runtime is under the gate while web-ui waits behind the explicitly annotated exclude. The accepted cost: the inter-tier discipline (upper tiers never re-test lower ones) is upheld by review rather than a machine gate, and web-ui's coverage gap persists until component specs fill in after the component redo.
+Each lane tests its own tier: touching any GUI source gets seconds-fast `test:gui` feedback, wire/object-layer semantics assert in milliseconds in Node, built-composition snapshots pin deterministic user-visible projection, and the browser carries wiring and carrier acceptance. The accepted cost is that inter-tier discipline is upheld by review rather than a machine gate and every new app snapshot must avoid unstable layout or clock output.
 
 ## Alternatives considered
 

.agents/notes/implemented/process/2026-07-20-gui-testing-system.zh.md

@@ -19,24 +19,24 @@ GUI 栈需要考虑多种应用形态，同应用形态内的不同运行环境
 | 层 | 被测物 | 关键手段 | 文件落点 |
 |---|---|---|---|
 | 1 协议同构层 | `AbstractApiClient` + `toFetchHandler`（双向数据/rpcId/ZOD类型/SSE 流/合批/超时） | **同构点全链**：`InProcessApiClient(toFetchHandler(脚本化 impl))` 不过网络但真跑 wire 序列化——零浏览器、纯 node env | `packages/host/apiproxy/tests/client-handler.spec.ts` |
-| 2 对象层编排 | `Session`/`SessionManager`/`ConnectionController`（状态机与时序：缝合/去重/翻页/乐观清稿/pendingBuffers/重连/退避） | **「事件序列进→快照出」黄金路径**：可编程假体 + deferred 控时序 + fake timers 控退避 | `packages/client/web-runtime/tests/{session,manager,connection,…}.spec.ts` |
-| 3 浏览器 smoke | 构建产物 × 真浏览器（页面起得来、一轮对话跑得通） | playwright 裸库（chromium headless，无 @playwright/test 框架）最简跑通；fixture 级 + 真 host 级（无 key self-skip） | `apps/web/tests/smoke-{fixture,real}.e2e.ts` |
+| 2 对象层编排 | `Session`/`SessionManager`/`ConnectionController`（状态机与时序：缝合/去重/翻页/乐观清稿/pendingBuffers/重连/退避） | **「事件序列进→快照出」黄金路径**：可编程假体 + deferred 控时序 + fake timers 控退避 | `packages/client/{runtime,connection}/tests/` |
+| 3 组装呈现层 | 构建产物 × 真实 client loader 与插件组合 | 归应用所有的语义快照会在 jsdom 下启动全部 8 个已构建的 client 插件，以固定确定性的跨插件状态变化；独立使用 Playwright 裸库的冒烟测试负责验证真实浏览器/承载层边界，真 host 用例在无密钥时自行跳过 | `apps/web/tests/*.snapshot.ts`、`apps/web/tests/smoke-{fixture,real}.e2e.ts` |
 
-层间纪律：**下层各测各的，上层不重测下层**——smoke 只证接线活着（fixture 级断零 `/api` 请求、零 pageerror），交互细节归 verify 脚本（见车道地图），wire 语义归 1 层，数据语义归 2 层。纯函数层（lineage/partial/notifier/fold-adapter）随 2 层同包 tests/ 零假体直测。
+层间纪律：**下层各测各的，上层不重测下层**：应用语义快照只固定组装后插件边界上的用户可见投影，Playwright 冒烟测试负责验证浏览器与承载层是否存活；wire 语义归 1 层，数据语义归 2 层。纯函数层（lineage/partial/notifier/fold-adapter）随 2 层同包 tests/ 零假体直测。
 
-- **host 侧**（apiproxy/runtime/webserver）：进全仓 `test:coverage` 门禁，per-file 100%。
-- **client 侧**：web-runtime **已进 per-file 100% 门禁**（12 处防御性不可达臂带理由 `/* v8 ignore */` 注释）；`vitest.config.ts` coverage.exclude 只剩 `packages/client/web-ui/src/**`（暂时——组件重做后随组件 specs 铺满逐步解除），测试照跑，只是不拉 web-ui src 进阈值。web-ui 走 **jsdom 路线（已落地）**：jsdom + @testing-library/react 入 root devDeps（dev-only），首个 spec `web-ui/tests/utils.spec.tsx`（utils 纯函数 + 组件 RTL render + hook uSES 探针）；环境用 per-file `// @vitest-environment jsdom` pragma，node env 的其他包零影响。
-- 排除是**显式注释的裁决**不是静默豁免；解除路径=删 exclude 行 + 补 justified 排除或补测。
+- **host 与 client 源码**均纳入全仓 per-file 100% 覆盖率门禁，仅排除 `vitest.config.ts` 中带注释的少量浏览器级例外；组件套件通过逐文件 jsdom pragma 和 Testing Library 运行，不会改变 Node 套件。
+- **归应用所有的语义快照**读取已构建的 client bundle，通过真实 loader 执行它们，并且只驱动确定性的 fixture 钩子。它们负责固定侧边栏标签、面包屑和 `document.title` 等稳定可见状态，而不固定 CSS 像素或下层状态机细节。
 
 ## 车道地图
 
 | 场景 | 命令 | 内容 | 何时跑 |
 |---|---|---|---|
 | 基础 | `pnpm run test:gui` | 1+2 层 vitest（`packages/client packages/host`），秒级、无浏览器无 server | 改 GUI 任意源码后随手跑 |
+| 语义快照 | `DSH_EXAMPLE_MODE=lib pnpm run test:snapshot` | 无需密钥的组装应用语义，以及仓库按传输形态划分的预期输出 | 用户可见的 GUI 变更后；交付前 |
 | 浏览器端到端 | `pnpm run test:web` | 先重建前端 dist，再跑 3 层双级 smoke（fixture 级 + 真 host 级 self-skip） | 改构建面/boot/承载后；交付前 |
-| 门禁 | `pnpm run test:coverage` | 全仓 gate（host 侧 GUI 包在内，client 侧 excluded） | PR 窗口 |
+| 门禁 | `pnpm run test:coverage` | 全仓 gate（host 与 client GUI 包均纳入，仅排除带注释的浏览器级例外） | PR 窗口 |
 
-**verify 脚本与 vitest 的分工**：verify 管浏览器黑盒回归（顺序步骤=用户操作剧本，共享一次浏览器会话，PASS/FAIL 流式输出供 agent 定位断点），vitest 管数据层语义一等断言（引用稳定性 `toBe`、状态机时序、wire 形）。两车道互补不收编——脚本不迁 vitest（拆散有序剧本是负收益），转正时包一层 spawn 壳挂 e2e 车道即可，脚本本体不改写。
+**浏览器脚本与 vitest 的分工**：Playwright 负责浏览器/承载层黑盒回归和较长的连续用户操作流程；普通 vitest 负责引用稳定性、时序和 wire 结构等数据层语义；快照 vitest 通过构建后的组合负责稳定的应用层语义输出。这些车道彼此互补，而不重复断言。
 
 ## 防回归纪律
 
@@ -46,7 +46,7 @@ GUI 栈需要考虑多种应用形态，同应用形态内的不同运行环境
 
 ## Consequences
 
-各车道各测各层：改任意 GUI 源码有秒级 `test:gui` 反馈，wire/对象层语义在 node env 毫秒级断言，浏览器只承担接线存活冒烟。门禁面上 host 侧全量进 per-file 100%；client 侧 web-runtime 已进门，web-ui 暂留显式注释的 exclude 之后。接受的代价：层间纪律（上层不重测下层）靠 review 而非机器门禁维持；web-ui 的覆盖缺口持续到组件重做后组件 specs 铺满为止。
+各车道各测各层：改动任意 GUI 源码后都能获得秒级 `test:gui` 反馈，wire/对象层语义在 Node 环境中进行毫秒级断言，基于构建后组合的快照固定确定性的用户可见投影，浏览器负责接线与承载层验收。接受的代价是层间纪律由评审而非机器门禁维持，而且每个新的应用快照都必须避开不稳定的布局或时钟输出。
 
 ## Alternatives considered
 

apps/cli/README.md

@@ -10,7 +10,7 @@ The TUI surface:
 - tells the agent where its own source lives: after boot it adds a prompt section naming this harness checkout, resolved from the launcher's real path so it holds under a PATH symlink and an arbitrary cwd, so the self-referential `cordis` toolset can read and modify it;
 - applies the personal overlay from `~/.dsh` (see [app-boot's Personal config](../../packages/ui/app-boot/README.md#personal-config)): `.env` fills environment gaps (ambient > project `.env` > personal `.env`), `config.yaml` patches the booted tree.
 
-The Web surface treats its invoking directory as the default project and loads applicable `AGENTS.md`/`CLAUDE.md` instructions into each agent-loop request prefix with a 65,536-byte render budget.
+The Web surface treats its invoking directory as the default project, loads applicable `AGENTS.md`/`CLAUDE.md` instructions into each agent-loop request prefix with a 65,536-byte render budget, and opts into first-message model titles. The headless surface retains deterministic fallback titles without making the auxiliary title-model request.
 
 ## Install (developer machine)
 

apps/cli/src/web.ts

@@ -40,6 +40,7 @@ export async function runWeb(argv: string[]): Promise<void> {
     boot: {
       persistenceRoot: './.sessions',
       workspaceContext: { maxBytes: 65_536 },
+      sessionTitleLlm: true,
     },
   })
 

apps/web/tests/session-title.snapshot.ts

@@ -0,0 +1,114 @@
+// @vitest-environment jsdom
+import { readFileSync } from 'node:fs'
+import { join } from 'node:path'
+import { act, cleanup, fireEvent, screen, waitFor, within } from '@testing-library/react'
+import { afterEach, beforeEach, expect, it, vi } from 'vitest'
+import type { BootPluginEntry } from '@deepseek-ai/dsh-client-runtime/client'
+import { bootWebShell } from '@deepseek-ai/dsh-client-web'
+
+const PLUGINS: readonly (BootPluginEntry & { dir: string })[] = [
+  { id: '@deepseek-ai/dsh-client-connection', dir: 'connection', url: '/plugins/connection.js', inject: [], immediately: true },
+  { id: '@deepseek-ai/dsh-client-runtime', dir: 'runtime', url: '/plugins/runtime.js', inject: ['@deepseek-ai/dsh-client-connection'], immediately: true },
+  { id: '@deepseek-ai/dsh-client-ui-theme', dir: 'ui-theme', url: '/plugins/ui-theme.js', inject: [], immediately: true },
+  { id: '@deepseek-ai/dsh-client-i18n', dir: 'i18n', url: '/plugins/i18n.js', inject: [], immediately: true },
+  { id: '@deepseek-ai/dsh-client-ui-layout', dir: 'ui-layout', url: '/plugins/ui-layout.js', inject: ['@deepseek-ai/dsh-client-runtime'] },
+  { id: '@deepseek-ai/dsh-client-ui-sidebar', dir: 'ui-sidebar', url: '/plugins/ui-sidebar.js', inject: ['@deepseek-ai/dsh-client-ui-layout'] },
+  { id: '@deepseek-ai/dsh-client-ui-conversation', dir: 'ui-conversation', url: '/plugins/ui-conversation.js', inject: ['@deepseek-ai/dsh-client-ui-layout'] },
+  { id: '@deepseek-ai/dsh-client-ui-trajectory', dir: 'ui-trajectory', url: '/plugins/ui-trajectory.js', inject: ['@deepseek-ai/dsh-client-ui-conversation'] },
+]
+
+const bundles = new Map(PLUGINS.map(plugin => [
+  plugin.url,
+  readFileSync(join(process.cwd(), 'packages/client', plugin.dir, 'lib/client.js'), 'utf8'),
+]))
+
+interface FixtureTiming {
+  appendTitle(id: string, title: string): void
+}
+
+interface FixtureWindow extends Window {
+  __DSH_BOOT__?: { plugins: BootPluginEntry[] }
+  DSHClientProxy?: unknown
+}
+
+class ResizeObserverStub {
+  observe(): void {}
+  disconnect(): void {}
+  unobserve(): void {}
+}
+
+const win = window as FixtureWindow
+let unmount: (() => void) | undefined
+
+beforeEach(() => {
+  localStorage.clear()
+  history.replaceState(null, '', '/?fixture')
+  document.title = 'DeepSeek Harness'
+  const root = document.createElement('div')
+  root.id = 'root'
+  document.body.appendChild(root)
+  vi.stubGlobal('ResizeObserver', ResizeObserverStub)
+  vi.stubGlobal('requestAnimationFrame', (callback: FrameRequestCallback) =>
+    setTimeout(() => { callback(0) }, 0) as unknown as number)
+  vi.stubGlobal('cancelAnimationFrame', (id: number) => { clearTimeout(id) })
+  win.__DSH_BOOT__ = { plugins: PLUGINS.map(({ dir: _dir, ...plugin }) => plugin) }
+})
+
+afterEach(() => {
+  act(() => { unmount?.() })
+  unmount = undefined
+  cleanup()
+  delete win.__DSH_BOOT__
+  delete win.DSHClientProxy
+  delete (globalThis as Record<string, unknown>).__fxTiming
+  document.body.innerHTML = ''
+  document.head.querySelectorAll('style[data-plugin]').forEach((style) => { style.remove() })
+  document.title = ''
+  history.replaceState(null, '', '/')
+  vi.unstubAllGlobals()
+})
+
+/** Read only the stable, user-facing title surfaces from the assembled app. */
+function titleSurfaces(label: string): { sidebar: string; breadcrumb: string; documentTitle: string } {
+  const tree = screen.getByRole('tree', { name: 'Sessions' })
+  const sidebar = within(tree).getByText(label).textContent ?? ''
+  const breadcrumb = within(screen.getByRole('navigation', { name: '会话层级' }))
+    .getByRole('button', { name: label }).textContent ?? ''
+  return { sidebar, breadcrumb, documentTitle: document.title }
+}
+
+it('projects initial and revised durable titles through the built eight-plugin fixture app', async () => {
+  const root = document.querySelector<HTMLElement>('#root')
+  if (root === null) throw new Error('snapshot root missing')
+  act(() => {
+    unmount = bootWebShell(root, {
+      fetchBundle: (url) => {
+        const code = bundles.get(url)
+        return code === undefined ? Promise.reject(new Error(`missing built bundle ${url}`)) : Promise.resolve(code)
+      },
+      executeBundle: (code) => { (0, eval)(code) },
+    })
+  })
+
+  const projectLabel = await screen.findByText('fixture', {}, { timeout: 10_000 })
+  const projectRow = projectLabel.closest<HTMLElement>('[role="treeitem"]')
+  if (projectRow === null) throw new Error('fixture project row missing')
+  fireEvent.click(projectRow)
+
+  const initialLabel = 'Fixture 历史会话'
+  const initialRowLabel = await screen.findByText(initialLabel)
+  const initialRow = initialRowLabel.closest<HTMLElement>('[role="treeitem"]')
+  if (initialRow === null) throw new Error('fixture session row missing')
+  fireEvent.click(initialRow)
+  await waitFor(() => { expect(document.title).toBe(`${initialLabel} — DeepSeek Harness`) })
+  const initial = titleSurfaces(initialLabel)
+
+  const revisedLabel = 'Fixture 修订标题'
+  const timing = (globalThis as Record<string, unknown>).__fxTiming as FixtureTiming
+  act(() => { timing.appendTitle('fx-alpha', revisedLabel) })
+  await waitFor(() => { expect(document.title).toBe(`${revisedLabel} — DeepSeek Harness`) })
+  const revised = titleSurfaces(revisedLabel)
+
+  await expect(`${JSON.stringify({ initial, revised }, null, 2)}\n`)
+    .toMatchFileSnapshot('./snapshots/session-title.json')
+})

apps/web/tests/smoke-fixture.e2e.ts

@@ -220,9 +220,11 @@ describe('web boot chain success pass (keyless, nine real bundles, ?fixture)', (
 
   it('renders and completes the resident question through the composer slot', async () => {
     onTestFailed(() => saveFailureShot(page, 'smoke-question-composer'))
-    await page.getByText('fixture', { exact: true }).click()
-    await page.locator('[role="treeitem"]').nth(1).click()
-    const composer = page.locator('[data-question-rpc-id]')
+    const sessionTree = page.getByRole('tree', { name: 'Sessions' })
+    const projectRow = sessionTree.getByRole('treeitem').filter({ hasText: '3 sessions' })
+    if (await projectRow.getAttribute('aria-expanded') === 'false') await projectRow.click()
+    await sessionTree.getByText('Fixture 历史会话', { exact: true }).click()
+    const composer = page.locator('[data-question-key]')
     await composer.waitFor({ timeout: 15_000 })
     expect({
       question: await composer.getByRole('heading').innerText(),

apps/web/tests/smoke-real.e2e.ts

@@ -77,6 +77,55 @@ async function rpc<T>(baseUrl: string, method: string, payload: unknown): Promis
   return body.result.value
 }
 
+interface HistoryPage {
+  events: { event: { type: string; data: unknown } }[]
+  hasMore: boolean
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null
+}
+
+function providerTitle(page: HistoryPage): string | undefined {
+  for (let index = page.events.length - 1; index >= 0; index--) {
+    const event = page.events[index]!.event
+    if (event.type !== 'session/title' || !isRecord(event.data)) continue
+    const source = event.data.source
+    if (typeof event.data.title === 'string' && isRecord(source) && source.kind === 'provider') {
+      return event.data.title
+    }
+  }
+  return undefined
+}
+
+function hasAssistantMarker(page: HistoryPage, marker: string): boolean {
+  return page.events.some(({ event }) => {
+    if (event.type !== 'assistant/message' || !isRecord(event.data) || !Array.isArray(event.data.content)) return false
+    return event.data.content.some(block =>
+      isRecord(block) && block.type === 'text' && typeof block.text === 'string' && block.text.includes(marker))
+  })
+}
+
+async function history(baseUrl: string, sessionId: string): Promise<HistoryPage> {
+  return rpc<HistoryPage>(baseUrl, 'session.history', { sessionId, maxMessages: 10 })
+}
+
+async function waitForProviderTitle(baseUrl: string, sessionId: string): Promise<string> {
+  let observed: string | undefined
+  await expect.poll(async () => {
+    observed = providerTitle(await history(baseUrl, sessionId))
+    return observed
+  }, { timeout: 90_000 }).toEqual(expect.any(String))
+  if (observed === undefined) throw new Error('provider-backed session title was not observed')
+  return observed
+}
+
+async function waitForAssistantMarker(baseUrl: string, sessionId: string, marker: string): Promise<void> {
+  await expect.poll(async () => hasAssistantMarker(await history(baseUrl, sessionId), marker), {
+    timeout: 120_000,
+  }).toBe(true)
+}
+
 /** W5 screenshot: evidence for the figma comparison, not a failure artifact. */
 async function screen(page: Page, name: string): Promise<void> {
   await page.screenshot({ path: join(REPO_ROOT, '.artifacts', `w5-${name}.png`) })
@@ -99,6 +148,7 @@ async function detailsTrack(page: Page): Promise<number> {
 // plugin's client bundle exists and exports apply, the loader fail-louds and
 // the frame never appears.
 const UI_PLUGIN_DIRS = ['connection', 'runtime', 'ui-theme', 'i18n', 'ui-layout', 'ui-sidebar', 'ui-conversation', 'ui-question', 'ui-trajectory']
+const ROUND_DONE_MARKER = 'WEB_ROUND_DONE'
 const notReady = UI_PLUGIN_DIRS.filter((dir) => {
   const bundle = join(REPO_ROOT, 'packages/client', dir, 'lib/client.js')
   return !existsSync(bundle) || !readFileSync(bundle, 'utf8').includes('exports.apply')
@@ -280,7 +330,8 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY || notReady.length > 0)('web smoke
     const input = page.locator('textarea').first()
     await input.waitFor({ timeout: 10_000 })
     await screen(page, '02-empty-state')
-    await input.fill('请简单介绍事件溯源，两句话即可，最后以「介绍完毕」结尾')
+    const prompt = `Please answer this request carefully: explain event sourcing in two sentences, ending with exactly ${ROUND_DONE_MARKER}.`
+    await input.fill(prompt)
     await input.press('Enter')
     // startSession chain: session mounts, composer moves to the bottom.
     // Regression pin (P0, 585671106): this send used to white-screen the tree
@@ -288,7 +339,32 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY || notReady.length > 0)('web smoke
     // near-empty here means that class of bug is back.
     await page.waitForFunction(() => document.body.innerText.length > 50, undefined, { timeout: 15_000 })
     expect(pageErrors).toEqual([])
-    await page.waitForFunction(() => document.body.innerText.includes('介绍完毕'), undefined, { timeout: 120_000 })
+    await page.waitForFunction(
+      () => document.title !== 'DeepSeek Harness' && document.title.endsWith(' — DeepSeek Harness'),
+      undefined,
+      { timeout: 15_000 },
+    )
+    await expect.poll(async () => (await rpc<{ items: { sessionId: string }[] }>(baseUrl, 'session.list', {})).items.length, {
+      timeout: 15_000,
+    }).toBe(1)
+    const sessions = await rpc<{ items: { sessionId: string }[] }>(baseUrl, 'session.list', {})
+    const sessionId = sessions.items[0]?.sessionId
+    if (sessionId === undefined) throw new Error('created Web session was not listed')
+    const durableTitle = await waitForProviderTitle(baseUrl, sessionId)
+    await page.waitForFunction(
+      expected => document.title === `${expected} — DeepSeek Harness`,
+      durableTitle,
+      { timeout: 15_000 },
+    )
+    const sessionTree = page.getByRole('tree', { name: 'Sessions' })
+    const projectRow = sessionTree.getByRole('treeitem').first()
+    if (await projectRow.getAttribute('aria-expanded') === 'false') await projectRow.click()
+    await Promise.all([
+      sessionTree.getByText(durableTitle, { exact: true }).waitFor({ timeout: 10_000 }),
+      page.getByRole('navigation').getByText(durableTitle, { exact: true }).waitFor({ timeout: 10_000 }),
+    ])
+    await waitForAssistantMarker(baseUrl, sessionId, ROUND_DONE_MARKER)
+    await page.locator('p').filter({ hasText: ROUND_DONE_MARKER }).waitFor({ timeout: 10_000 })
     await screen(page, '04-round-complete')
   }, 150_000)
 
@@ -308,10 +384,10 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY || notReady.length > 0)('web smoke
     await input.fill('请用 bash 工具运行命令 echo w5marker 然后告诉我结果')
     await input.press('Enter')
     // Wait for the tool ROW, not response text (the reply echoes any marker).
-    // bash renders through the third-party sample registration (data-sample) —
-    // that IS the differential-rendering acceptance; the generic path renders
-    // data-variant rows with the handler on the data-clickable inner row.
-    const toolRow = page.locator('[data-sample], [data-variant] [data-clickable]').first()
+    // Bash renders through the third-party sample registration. Match that
+    // exact row: other clickable variants (for example Think disclosure)
+    // may precede the tool call in document order.
+    const toolRow = page.locator('[data-sample="bash-global"]')
     await toolRow.waitFor({ timeout: 120_000 })
     await screen(page, '08-bash-round')
     expect(await detailsTrack(page)).toBe(0)
@@ -363,7 +439,7 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY || notReady.length > 0)('web smoke
     onTestFailed(() => saveFailureShot(page, 'w5-reload'))
     await page.reload({ waitUntil: 'load' })
     await page.waitForSelector('[class*="frame"]', { timeout: 30_000 })
-    await page.waitForFunction(() => document.body.innerText.includes('介绍完毕'), undefined, { timeout: 30_000 })
+    await page.locator('p').filter({ hasText: ROUND_DONE_MARKER }).waitFor({ timeout: 30_000 })
     await screen(page, '12-reload-recovery')
   })
 

apps/web/tests/snapshots/session-title.json

@@ -0,0 +1,12 @@
+{
+  "initial": {
+    "sidebar": "Fixture 历史会话",
+    "breadcrumb": "Fixture 历史会话",
+    "documentTitle": "Fixture 历史会话 — DeepSeek Harness"
+  },
+  "revised": {
+    "sidebar": "Fixture 修订标题",
+    "breadcrumb": "Fixture 修订标题",
+    "documentTitle": "Fixture 修订标题 — DeepSeek Harness"
+  }
+}

docs/core-data-structures/core.md

@@ -238,10 +238,10 @@ interface GenerateOptions {
   sessionId?: Branded<'SessionId'>
   /**
    * Provider-neutral classification for an auxiliary model call. Adapters may
-   * map the purpose to model-hidden transport metadata. Ordinary conversation
-   * requests leave it unset.
+   * map the purpose to model-hidden transport metadata or purpose-specific
+   * generation policy. Ordinary conversation requests leave it unset.
    */
-  purpose?: 'compaction'
+  purpose?: 'compaction' | 'session-title'
 }
 ```
 

knip.json

@@ -555,6 +555,7 @@
     "apps/web": {
       "entry": [
         "tests/**/*.e2e.ts",
+        "tests/**/*.snapshot.ts",
         "tests/support.ts"
       ],
       "project": [
@@ -562,7 +563,6 @@
         "tests/**/*.ts"
       ],
       "ignoreDependencies": [
-        "@deepseek-ai/dsh-client-runtime",
         "@deepseek-ai/dsh-client-ui-primitives",
         "@deepseek-ai/dsh-client-ui-slots",
         "@deepseek-ai/dsh-client-web-react",

packages/client/connection/src/client/fixture.ts

@@ -62,13 +62,19 @@ function buildAlphaLog(): SessionEvent[] {
   }
   for (let turn = 0; turn < 60; turn++) {
     push({ type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } })
-    push({
+    const userSeq = push({
       type: 'user/message', surfaceOp: 'append',
       data: {
         content: text(turn === 59 ? USER_MARKDOWN_LITERAL : `问题 ${turn}：fixture 历史消息，用于翻页与渲染验收。`),
         source: { kind: 'user' },
       },
     })
+    if (turn === 0) {
+      push({
+        type: 'session/title',
+        data: { title: 'Fixture 历史会话', messageSeqs: [userSeq], source: { kind: 'fallback' } },
+      })
+    }
     if (turn % 9 === 4) {
       push({ type: 'context/message', surfaceOp: 'append', data: { content: text(`[fixture] 上下文注入（turn ${turn}）`), source: { kind: 'plugin', plugin: 'fixture' } } })
     }
@@ -187,6 +193,20 @@ function viewFor(event: SessionEvent, log: readonly SessionEvent[]): ToolEventVi
   return undefined
 }
 
+/** Fold the latest fixture title into the host's control-frame projection. */
+function titleFrameOf(id: SessionId, log: readonly SessionEvent[]): Extract<MuxFrame, { type: 'session/title' }> | undefined {
+  const event = log.findLast(item => (item as { type: string }).type === 'session/title')
+  if (event === undefined) return undefined
+  const titleEvent = event as unknown as { seq: number; time: number; data: { title: string } }
+  return {
+    type: 'session/title',
+    sessionId: id,
+    title: titleEvent.data.title,
+    eventSeq: titleEvent.seq,
+    updatedAt: titleEvent.time,
+  }
+}
+
 /**
  * Message-boundary paging (mirrors the host's paging contract): count
  * maxMessages messages
@@ -361,6 +381,10 @@ export function createFixtureApi(): ApiProxy {
     emitMux(view === undefined
       ? { type: 'session/event', sessionId: id, event }
       : { type: 'session/event', sessionId: id, event, view })
+    if ((event as { type: string }).type === 'session/title') {
+      // The raw title is already in this log, so the latest-title fold must find it.
+      emitMux(titleFrameOf(id, log) as Extract<MuxFrame, { type: 'session/title' }>)
+    }
   }
 
   /** At most one in-flight replay per session; cancel clears it. */
@@ -389,6 +413,12 @@ export function createFixtureApi(): ApiProxy {
     appendUser(id: string, msg: string): void {
       append(sid(id), { type: 'user/message', surfaceOp: 'append', data: { content: text(msg), source: { kind: 'user' } } })
     },
+    /** Append a later durable title revision through the normal raw-event + control-frame path. */
+    appendTitle(id: string, title: string): void {
+      const log = logOf(sid(id))
+      const messageSeqs = log.filter(event => event.type === 'user/message').map(event => event.seq)
+      append(sid(id), { type: 'session/title', data: { title, messageSeqs, source: { kind: 'provider', provider: 'fixture' } } })
+    },
     /** Log append WITHOUT the mux emit: a frame lost in transit — history still serves it, the client must repull. */
     appendSilent(id: string, msg: string): void {
       const log = logOf(sid(id))
@@ -506,6 +536,8 @@ export function createFixtureApi(): ApiProxy {
         for (const s of sessions) {
           if (!s.running) continue
           conn.push({ rpcId: mint(), payload: { type: 'session/subscribed', sessionId: s.sessionId, lastSeq: (logs.get(s.sessionId)?.length ?? 0) - 1 } })
+          const title = titleFrameOf(s.sessionId, logs.get(s.sessionId) ?? [])
+          if (title !== undefined) conn.push({ rpcId: mint(), payload: title })
         }
         conn.push({
           rpcId: pendingApprovalRpcId,

packages/client/connection/tests/fixture.spec.ts

@@ -18,6 +18,7 @@ interface TimingHooks {
   setHistoryDelay(ms: number): void
   failNextHistory(): void
   appendUser(id: string, msg: string): void
+  appendTitle(id: string, title: string): void
   appendSilent(id: string, msg: string): void
   breakStreams(): void
 }
@@ -155,7 +156,7 @@ describe('createFixtureApi', () => {
       const envelopes: RpcRequest<MuxFrame>[] = []
       for await (const envelope of api.events.mux(req({}), abort.signal)) {
         envelopes.push(envelope)
-        if (envelopes.length >= 3) abort.abort()
+        if (envelopes.length >= 4) abort.abort()
       }
       return envelopes
     }
@@ -163,10 +164,11 @@ describe('createFixtureApi', () => {
     const second = await openOnce()
     expect(first[0]?.payload).toMatchObject({ type: 'session/subscribed', sessionId: 'fx-alpha' })
     expect((first[0]?.payload as { lastSeq: number }).lastSeq).toBeGreaterThan(0)
-    expect(first[1]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
-    expect(second[1]?.rpcId).toBe(first[1]?.rpcId) // stable rpcId across replays (host replay semantics)
-    expect(first[2]?.payload).toMatchObject({ type: 'question/requested', sessionId: 'fx-alpha' })
-    expect(second[2]?.rpcId).toBe(first[2]?.rpcId)
+    expect(first[1]?.payload).toMatchObject({ type: 'session/title', sessionId: 'fx-alpha', title: 'Fixture 历史会话' })
+    expect(first[2]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
+    expect(second[2]?.rpcId).toBe(first[2]?.rpcId) // stable rpcId across replays (host replay semantics)
+    expect(first[3]?.payload).toMatchObject({ type: 'question/requested', sessionId: 'fx-alpha' })
+    expect(second[3]?.rpcId).toBe(first[3]?.rpcId)
   })
 
   it('steer with no replay in flight falls through to a fresh queued turn; non-text blocks stringify empty', async () => {
@@ -279,10 +281,15 @@ describe('createFixtureApi', () => {
     await new Promise(resolve => setTimeout(resolve, 10))
     hooks.appendSilent('fx-alpha', '静默丢帧')
     hooks.appendUser('fx-alpha', '正常直播')
+    hooks.appendTitle('fx-alpha', 'Fixture 修订标题')
     await vi.waitFor(() => {
       expect(seen.some(f => f.type === 'session/event' && JSON.stringify(f.event.data).includes('正常直播'))).toBe(true)
+      expect(seen.some(f => f.type === 'session/title' && f.title === 'Fixture 修订标题')).toBe(true)
     })
     expect(seen.some(f => f.type === 'session/event' && JSON.stringify(f.event.data).includes('静默丢帧'))).toBe(false)
+    const rawTitleIndex = seen.findIndex(f => f.type === 'session/event' && (f.event as { type: string }).type === 'session/title')
+    const titleControlIndex = seen.findIndex(f => f.type === 'session/title' && f.title === 'Fixture 修订标题')
+    expect(titleControlIndex).toBe(rawTitleIndex + 1)
     // But history serves the silent event (the client's repull finds it).
     const repull = await api.sessions.history(req({ sessionId: sid('fx-alpha'), maxMessages: 5 }))
     if (!repull.result.ok) throw new Error('repull failed')

packages/client/runtime/README.md

@@ -2,6 +2,10 @@
 
 Client cordis boot + core services: SlotsService (Service wrapper over SlotCore + 'slots/changed' bridge), SessionsService (list store projection, scope tree, bindings, ancestry), the Session object layer (exported as a type; instances are owned and handed out by SessionsService — the manager/paging internals stay package-internal, tests reach them via src), ClientLoader (`./loader` subpath, statically held by the shell). Contract: api-contracts v3 §4.
 
+## Session title projection
+
+`SessionManager` retains the latest validated `session/title` control snapshot independently of list and session-instance arrival. Newer event seqs replace older snapshots, title timestamps contribute to list recency, and a subscription baseline discards any retained title beyond its `lastSeq` before the optional folded title arrives. Explicit session removal also clears the retained title. The client-facing `SessionSummary.title` is therefore only the actual durable title; `displayTitle` is always present and falls back through the cwd basename and session id. A cold persisted session keeps that fallback until opening or resuming it causes the host to fold and project its log-backed title.
+
 ## Model Experience
 
 None, as the client runtime hosts browser-side services and the session object layer; nothing here reaches a model request.
@@ -15,4 +19,3 @@ None; this package neither assembles nor sends a provider request.
 - **`loader.unload` is a stub (throws not-implemented)** — the full chain (fiber dispose → registration cascade → style removal) lands with the HMR project.
 - **Scope teardown is stage-driven, single-occupant today** — the staged session follows `list.current` exactly (staging is the open signal: the event window opens ⟺ the session is on stage); a removed-while-staged session's scope survives frozen until the stage moves on, not until true observer count reaches zero. Resolution (`cell()`/`binding()`/`scope()`) is pure addressing, render-safe. The staged state can widen to a multi-pane list when concurrent panes land.
 - **Value imports of this package from plugin bundles must use the `/client` subpath** — the bare package name is not in the loader externals table and inlines a second module instance, whose private scope-tag Symbol never matches (the empty-state P0 postmortem).
-- **`SessionSummary.title` is a display projection** — the wire summary carries no title yet; the cwd basename stands in, then the raw id.

packages/client/runtime/src/client/sessions/lineage.ts

@@ -4,9 +4,15 @@
 
 import type { SessionId, SessionSummary } from '@deepseek-ai/dsh-client-connection/client'
 
+/** Host list summary enriched with the latest mux-projected durable title. */
+export interface TitledSessionSummary extends SessionSummary {
+  title?: string
+}
+
 /** One flattened session-list row (summary + lineage indent depth). */
 export interface SessionListEntry {
   sessionId: SessionId
+  title?: string
   updatedAt: number
   running: boolean
   parentSessionId?: SessionId
@@ -21,12 +27,12 @@ export interface SessionListEntry {
  * @param summaries - the host's session.list items.
  * @returns display rows in render order.
  */
-export function flattenLineage(summaries: readonly SessionSummary[]): SessionListEntry[] {
-  const byId = new Map<SessionId, SessionSummary>()
+export function flattenLineage(summaries: readonly TitledSessionSummary[]): SessionListEntry[] {
+  const byId = new Map<SessionId, TitledSessionSummary>()
   for (const s of summaries) byId.set(s.sessionId, s)
 
-  const children = new Map<SessionId, SessionSummary[]>()
-  const roots: SessionSummary[] = []
+  const children = new Map<SessionId, TitledSessionSummary[]>()
+  const roots: TitledSessionSummary[] = []
   for (const s of summaries) {
     if (s.parentSessionId !== undefined && byId.has(s.parentSessionId)) {
       const list = children.get(s.parentSessionId) ?? []
@@ -37,12 +43,12 @@ export function flattenLineage(summaries: readonly SessionSummary[]): SessionLis
     }
   }
 
-  const byUpdatedDesc = (a: SessionSummary, b: SessionSummary): number => b.updatedAt - a.updatedAt
+  const byUpdatedDesc = (a: TitledSessionSummary, b: TitledSessionSummary): number => b.updatedAt - a.updatedAt
   roots.sort(byUpdatedDesc)
 
   const out: SessionListEntry[] = []
   const visited = new Set<SessionId>()
-  const walk = (s: SessionSummary, depth: number): void => {
+  const walk = (s: TitledSessionSummary, depth: number): void => {
     if (visited.has(s.sessionId)) {
       console.warn(`[web-runtime] lineage cycle at ${s.sessionId}; emitting as root`)
       return

packages/client/runtime/src/client/sessions/manager.ts

@@ -4,7 +4,7 @@
 
 import type { IApiClient, HostFrame, MuxFrame, RpcError, RpcRequest, RpcResult, SessionId, SessionSummary } from '@deepseek-ai/dsh-client-connection/client'
 import { transportError } from '@deepseek-ai/dsh-client-connection/client'
-import type { SessionListEntry } from './lineage.ts'
+import type { SessionListEntry, TitledSessionSummary } from './lineage.ts'
 import { flattenLineage } from './lineage.ts'
 import { Notifier } from './notifier.ts'
 import { Session } from './session.ts'
@@ -19,6 +19,13 @@ export interface SessionListSnapshot {
 /** Per-session cap for pre-instantiation approval/question buffering (low-frequency frames; a few dozen covers any real backlog). */
 const PENDING_BUFFER_CAP = 32
 
+/** Latest title control snapshot retained independently of list/instance arrival. */
+interface SessionTitleSnapshot {
+  title: string
+  eventSeq: number
+  updatedAt: number
+}
+
 /** Instance cluster + frame entry + the session list (see the web client architecture RFC). */
 export class SessionManager {
   private readonly sessions = new Map<SessionId, Session>()
@@ -27,6 +34,7 @@ export class SessionManager {
    *  drop-and-backfill path; replayed and cleared on instantiation. Bounded per session (these
    *  frames are low-frequency; overflow drops oldest) and dropped on session-removed (audit S7). */
   private readonly pendingBuffers = new Map<SessionId, RpcRequest<MuxFrame>[]>()
+  private readonly titleSnapshots = new Map<SessionId, SessionTitleSnapshot>()
   private summaries: SessionSummary[] = []
   private listState: 'idle' | 'loading' | 'error' = 'idle'
   private listError: RpcError | null = null
@@ -158,6 +166,24 @@ export class SessionManager {
   handleMuxEnvelope(envelope: RpcRequest<MuxFrame>): void {
     const frame = envelope.payload
     if (frame.type === 'stream/error') return // Controller already treats this as stream failure
+    if (frame.type === 'session/title') {
+      const current = this.titleSnapshots.get(frame.sessionId)
+      if (current !== undefined && current.eventSeq >= frame.eventSeq) return
+      this.titleSnapshots.set(frame.sessionId, {
+        title: frame.title,
+        eventSeq: frame.eventSeq,
+        updatedAt: frame.updatedAt,
+      })
+      this.notifier.markDirty()
+      return
+    }
+    if (frame.type === 'session/subscribed') {
+      const current = this.titleSnapshots.get(frame.sessionId)
+      if (current !== undefined && current.eventSeq > frame.lastSeq) {
+        this.titleSnapshots.delete(frame.sessionId)
+        this.notifier.markDirty()
+      }
+    }
     const session = this.sessions.get(frame.sessionId)
     if (session === undefined) {
       // Approval/question frames never hit history: buffer for replay on instantiation;
@@ -204,6 +230,7 @@ export class SessionManager {
         this.summaries = this.summaries.filter(s => s.sessionId !== frame.sessionId)
         this.sessions.get(frame.sessionId)?.handleRemoved() // instance survives (resident-instance rule), only flagged in the snapshot
         this.pendingBuffers.delete(frame.sessionId) // a removed session's buffered frames must not replay on a future instantiation
+        this.titleSnapshots.delete(frame.sessionId)
         this.notifier.markDirty()
         return
       }
@@ -230,12 +257,19 @@ export class SessionManager {
   }
 
   private buildListSnapshot(): SessionListSnapshot {
-    const fresh = flattenLineage(this.summaries)
+    const merged: TitledSessionSummary[] = this.summaries.map((summary) => {
+      const title = this.titleSnapshots.get(summary.sessionId)
+      return title === undefined
+        ? summary
+        : { ...summary, title: title.title, updatedAt: Math.max(summary.updatedAt, title.updatedAt) }
+    })
+    const fresh = flattenLineage(merged)
     const items = fresh.map((entry) => {
       const prev = this.entryCache.get(entry.sessionId)
       if (
         prev !== undefined && prev.updatedAt === entry.updatedAt && prev.running === entry.running
-        && prev.parentSessionId === entry.parentSessionId && prev.cwd === entry.cwd && prev.depth === entry.depth
+        && prev.parentSessionId === entry.parentSessionId && prev.cwd === entry.cwd
+        && prev.title === entry.title && prev.depth === entry.depth
       ) return prev
       this.entryCache.set(entry.sessionId, entry)
       return entry

packages/client/runtime/src/client/sessions/service.ts

@@ -25,7 +25,10 @@ import type { Session } from './session.ts'
 /** Session list row projected from the host list RPC plus live stream increments. */
 export interface SessionSummary {
   id: SessionId
-  title: string
+  /** Latest durable log-backed title, absent until the host projects one. */
+  title?: string
+  /** Human-facing label: durable title, project basename, then session id. */
+  displayTitle: string
   cwd?: string
   parentId?: SessionId
   running: boolean
@@ -62,10 +65,11 @@ export function scopeOf(ctx: Context): SessionId | undefined {
 function sessionScope(): void {}
 
 /**
- * Display title projection. The wire summary carries no title yet (P-I
- * ledger): the project directory's basename stands in, then the raw id.
+ * Display title projection: durable title, project directory basename, then
+ * the raw id.
  */
-function titleOf(cwd: string | undefined, id: SessionId): string {
+function displayTitleOf(title: string | undefined, cwd: string | undefined, id: SessionId): string {
+  if (title !== undefined) return title
   if (cwd !== undefined && cwd !== '') {
     const base = cwd.replace(/[/\\]+$/, '').split(/[/\\]/).pop()
     if (base !== undefined && base !== '') return base
@@ -259,9 +263,10 @@ export class SessionsService {
       ids.push(entry.sessionId)
       byId[entry.sessionId] = {
         id: entry.sessionId,
-        title: titleOf(entry.cwd, entry.sessionId),
+        displayTitle: displayTitleOf(entry.title, entry.cwd, entry.sessionId),
         running: entry.running,
         updatedAt: entry.updatedAt,
+        ...(entry.title !== undefined ? { title: entry.title } : {}),
         ...(entry.cwd !== undefined ? { cwd: entry.cwd } : {}),
         ...(entry.parentSessionId !== undefined ? { parentId: entry.parentSessionId } : {}),
       }

packages/client/runtime/tests/manager.spec.ts

@@ -89,6 +89,66 @@ describe('list lifecycle', () => {
     expect(result).toMatchObject({ ok: true, value: { sessionId: S2 } })
     expect(manager.getListSnapshot().items.map(i => i.sessionId)).toEqual([S2])
   })
+
+  it('retains monotonic title snapshots before list arrival, merges recency, and clears them on removal', async () => {
+    const api = new FakeApiClient()
+    const manager = new SessionManager(api)
+    manager.handleMuxEnvelope({
+      rpcId: 'title-new' as never,
+      payload: { type: 'session/title', sessionId: S1, title: 'Newest', eventSeq: 4, updatedAt: 300 },
+    })
+    manager.handleMuxEnvelope({
+      rpcId: 'title-stale' as never,
+      payload: { type: 'session/title', sessionId: S1, title: 'Stale', eventSeq: 3, updatedAt: 900 },
+    })
+    manager.handleMuxEnvelope({
+      rpcId: 'title-equal' as never,
+      payload: { type: 'session/title', sessionId: S1, title: 'Equal', eventSeq: 4, updatedAt: 901 },
+    })
+    api.onList = () => Promise.resolve(ok({
+      items: [summary(S1), summary(S2, { updatedAt: 200 })] as never[],
+    }))
+    await manager.refreshList()
+
+    const titled = manager.getListSnapshot()
+    expect(titled.items.map(item => item.sessionId)).toEqual([S1, S2])
+    expect(titled.items[0]).toMatchObject({ title: 'Newest', updatedAt: 300 })
+    expect(titled.items[1]?.title).toBeUndefined()
+
+    manager.handleHostEnvelope({ rpcId: 'removed' as never, payload: { type: 'host/session-removed', sessionId: S1 } })
+    manager.handleHostEnvelope({ rpcId: 'readded' as never, payload: { type: 'host/session-added', sessionId: S1 } })
+    expect(manager.getListSnapshot().items.find(item => item.sessionId === S1)?.title).toBeUndefined()
+  })
+
+  it('drops a retained title beyond the subscription baseline before accepting its durable replay', async () => {
+    const api = new FakeApiClient()
+    api.onList = () => Promise.resolve(ok({ items: [summary(S1)] as never[] }))
+    const manager = new SessionManager(api)
+    await manager.refreshList()
+    manager.handleMuxEnvelope({
+      rpcId: 'title-unflushed' as never,
+      payload: { type: 'session/title', sessionId: S1, title: 'Unflushed', eventSeq: 4, updatedAt: 400 },
+    })
+
+    manager.handleMuxEnvelope({
+      rpcId: 'subscribed-recovered' as never,
+      payload: { type: 'session/subscribed', sessionId: S1, lastSeq: 2 },
+    })
+    expect(manager.getListSnapshot().items[0]?.title).toBeUndefined()
+    expect(manager.getListSnapshot().items[0]?.updatedAt).toBe(100)
+
+    manager.handleMuxEnvelope({
+      rpcId: 'title-durable' as never,
+      payload: { type: 'session/title', sessionId: S1, title: 'Durable', eventSeq: 2, updatedAt: 200 },
+    })
+    expect(manager.getListSnapshot().items[0]).toMatchObject({ title: 'Durable', updatedAt: 200 })
+
+    manager.handleMuxEnvelope({
+      rpcId: 'subscribed-current' as never,
+      payload: { type: 'session/subscribed', sessionId: S1, lastSeq: 2 },
+    })
+    expect(manager.getListSnapshot().items[0]).toMatchObject({ title: 'Durable', updatedAt: 200 })
+  })
 })
 
 describe('host frame routing', () => {

packages/client/runtime/tests/sessions-service.spec.ts

@@ -41,16 +41,21 @@ async function feedList(b: Bench, rows: { id: string; cwd?: string; parentId?: s
 }
 
 describe('list store projection', () => {
-  it('projects ids/byId with cwd-basename titles (id fallback) and parent links', async () => {
+  it('projects durable titles separately from cwd/id display fallbacks and parent links', async () => {
     const b = bench()
+    b.svc.manager.handleMuxEnvelope({
+      rpcId: 'title' as never,
+      payload: { type: 'session/title', sessionId: sid('s1'), title: 'Durable title', eventSeq: 2, updatedAt: 3 },
+    })
     await feedList(b, [
       { id: 's1', cwd: '/home/u/proj-a/' },
       { id: 's2', parentId: 's1', running: true },
     ])
     const state = b.svc.list.getSnapshot()
     expect(state.ids).toEqual(['s1', 's2'])
-    expect(state.byId[sid('s1')]).toMatchObject({ title: 'proj-a', cwd: '/home/u/proj-a/' })
-    expect(state.byId[sid('s2')]).toMatchObject({ title: 's2', parentId: 's1', running: true })
+    expect(state.byId[sid('s1')]).toMatchObject({ title: 'Durable title', displayTitle: 'Durable title', cwd: '/home/u/proj-a/' })
+    expect(state.byId[sid('s2')]).toMatchObject({ displayTitle: 's2', parentId: 's1', running: true })
+    expect(state.byId[sid('s2')]?.title).toBeUndefined()
   })
 
   it('reflects live increments (host stream via manager) into the store', async () => {
@@ -273,12 +278,13 @@ describe('create', () => {
 })
 
 describe('coverage tails (branch duals)', () => {
-  it('titleOf falls back to the id for empty and separator-only cwd', async () => {
+  it('displayTitleOf falls back to the id for empty and separator-only cwd', async () => {
     const b = bench()
     await feedList(b, [{ id: 'no-base', cwd: '///' }, { id: 'empty-cwd', cwd: '' }])
     const { byId } = b.svc.list.getSnapshot()
-    expect(byId[sid('no-base')]?.title).toBe('no-base')
-    expect(byId[sid('empty-cwd')]?.title).toBe('empty-cwd')
+    expect(byId[sid('no-base')]?.displayTitle).toBe('no-base')
+    expect(byId[sid('empty-cwd')]?.displayTitle).toBe('empty-cwd')
+    expect(byId[sid('no-base')]?.title).toBeUndefined()
   })
 
   it('binding for an unknown session returns undefined and leaves the staged scope intact', async () => {

packages/client/ui-conversation/src/client/skeleton/ConversationRoot.tsx

@@ -90,7 +90,7 @@ export function ConversationRoot({
                     disabled={last}
                     onClick={() => { open(s.id) }}
                   >
-                    {s.title}
+                    {s.displayTitle}
                   </button>
                 </span>
               )

packages/client/ui-conversation/tests/apply-inject.spec.tsx

@@ -51,7 +51,7 @@ async function bench() {
 
   const listStore = createSnapshotStore<SessionListState>({
     ids: [ROOT],
-    byId: { [ROOT]: { id: ROOT, title: 'R', cwd: '/proj', running: false, updatedAt: 1 } },
+    byId: { [ROOT]: { id: ROOT, title: 'R', displayTitle: 'R', cwd: '/proj', running: false, updatedAt: 1 } },
     current: ROOT,
   } as SessionListState)
   const sessionFake = {

packages/client/ui-conversation/tests/chat-apply.spec.tsx

@@ -26,8 +26,8 @@ async function bench() {
   const listStore = createSnapshotStore<SessionListState>({
     ids: [ROOT, CHILD],
     byId: {
-      [ROOT]: { id: ROOT, title: 'R', running: false, updatedAt: 1 },
-      [CHILD]: { id: CHILD, title: 'C', parentId: ROOT, running: false, updatedAt: 2 },
+      [ROOT]: { id: ROOT, title: 'R', displayTitle: 'R', running: false, updatedAt: 1 },
+      [CHILD]: { id: CHILD, title: 'C', displayTitle: 'C', parentId: ROOT, running: false, updatedAt: 2 },
     },
     current: undefined,
   } as SessionListState)

packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx

@@ -122,8 +122,8 @@ describe('bash sample row', () => {
     return createSnapshotStore<SessionListState>({
       ids: [ROOT, CHILD],
       byId: {
-        [ROOT]: { id: ROOT, title: 'r', running: false, updatedAt: 0 },
-        [CHILD]: { id: CHILD, title: 'c', parentId: ROOT, running: false, updatedAt: 0 },
+        [ROOT]: { id: ROOT, title: 'r', displayTitle: 'r', running: false, updatedAt: 0 },
+        [CHILD]: { id: CHILD, title: 'c', displayTitle: 'c', parentId: ROOT, running: false, updatedAt: 0 },
       },
       current: undefined,
     } as SessionListState)
@@ -157,7 +157,7 @@ describe('bash sample row', () => {
     const orphan = 'late-child' as SessionId
     store.update((d) => {
       d.ids.push(orphan)
-      d.byId[orphan] = { id: orphan, title: 'l', running: false, updatedAt: 0 }
+      d.byId[orphan] = { id: orphan, title: 'l', displayTitle: 'l', running: false, updatedAt: 0 }
     })
     const view = render(<BashRow {...rowProps(orphan, { store })} />)
     expect(view.container.querySelector('[data-sample="bash-global"]')).not.toBeNull()

packages/client/ui-conversation/tests/selection-survival.spec.ts

@@ -123,23 +123,25 @@ describe('selection survives on the store seat', () => {
     expect(two.store.getSnapshot().selection).toEqual({ turnSeq: 9, callId: 'z' })
   })
 
-  it('a title-upgrading list refresh keeps instance identity and the selection value', async () => {
+  it('a display-title-upgrading list refresh keeps instance identity and the selection value', async () => {
     const b = bench()
     // First-send shape: client-side create inserts the row without cwd (title = bare id).
     b.api.onCreate = () => Promise.resolve(ok({ sessionId: sid('s1') }))
     const id = await b.sessions.create({})
     await flush()
-    expect(b.sessions.list.getSnapshot().byId[id]?.title).toBe('s1')
+    expect(b.sessions.list.getSnapshot().byId[id]).toMatchObject({ displayTitle: 's1' })
+    expect(b.sessions.list.getSnapshot().byId[id]?.title).toBeUndefined()
 
     const store = storeFor(b, 'conversation', id)
     store.actions.select({ turnSeq: 3, callId: 'c1' })
     store.actions.setDraft('half-typed')
 
-    // The late list refresh lands (host knows the cwd → formal title).
+    // The late list refresh lands (host knows the cwd → better fallback label).
     feed(b, [{ id: 's1', cwd: '/w/proj-a' }])
     await b.sessions.manager.refreshList()
     await flush()
-    expect(b.sessions.list.getSnapshot().byId[id]?.title).toBe('proj-a')
+    expect(b.sessions.list.getSnapshot().byId[id]).toMatchObject({ displayTitle: 'proj-a' })
+    expect(b.sessions.list.getSnapshot().byId[id]?.title).toBeUndefined()
 
     const after = storeFor(b, 'conversation', id)
     expect(after).toBe(store)

packages/client/ui-conversation/tests/skeleton-branches.spec.tsx

@@ -46,7 +46,7 @@ function listHook(rows: { id: string; title: string; cwd?: string; parentId?: st
   const store = createSnapshotStore<SessionListState>({
     ids: rows.map(r => r.id as SessionId),
     byId: Object.fromEntries(rows.map(r => [r.id, {
-      id: r.id as SessionId, title: r.title, running: false, updatedAt: 1,
+      id: r.id as SessionId, title: `durable ${r.title}`, displayTitle: r.title, running: false, updatedAt: 1,
       ...(r.cwd !== undefined ? { cwd: r.cwd } : {}),
       ...(r.parentId !== undefined ? { parentId: r.parentId as SessionId } : {}),
     }])),

packages/client/ui-conversation/tests/skeleton.spec.tsx

@@ -53,7 +53,7 @@ function fakeSessions(rows: { id: string; title: string; cwd?: string; parentId?
   const store = createSnapshotStore<SessionListState>({
     ids: rows.map(r => sid(r.id)),
     byId: Object.fromEntries(rows.map(r => [r.id, {
-      id: sid(r.id), title: r.title, running: false, updatedAt: 1,
+      id: sid(r.id), title: `durable ${r.title}`, displayTitle: r.title, running: false, updatedAt: 1,
       ...(r.cwd !== undefined ? { cwd: r.cwd } : {}),
       ...(r.parentId !== undefined ? { parentId: sid(r.parentId) } : {}),
     }])),

packages/client/ui-sidebar/src/client/tree.ts

@@ -154,7 +154,7 @@ function sessionRow(g: Group, s: SessionSummary, depth: number, hasChildren: boo
     type: 'session',
     id: s.id,
     groupKey: g.key,
-    title: s.title,
+    title: s.displayTitle,
     depth,
     hasChildren,
     expanded,
@@ -183,7 +183,7 @@ function flattenVisible(g: Group, expandedSessions: ReadonlySet<string>, rows: S
 function searchVisible(g: Group, q: string): Set<SessionId> {
   const visible = new Set<SessionId>()
   for (const m of g.summaries.values()) {
-    if (!m.title.toLowerCase().includes(q)) continue
+    if (!m.displayTitle.toLowerCase().includes(q)) continue
     let cur: SessionSummary | undefined = m
     while (cur !== undefined && !visible.has(cur.id)) {
       visible.add(cur.id)
@@ -213,9 +213,9 @@ function flattenSearch(g: Group, visible: ReadonlySet<SessionId>, rows: SidebarR
  *
  * Normal mode: every project row shows; sessions show under expanded
  * projects, descending only into expanded sessions. Search mode (non-blank
- * query, case-insensitive title substring): expansion state is ignored —
+ * query, case-insensitive display-title substring): expansion state is ignored —
  * matched sessions and their ancestor chains are forced visible, groups
- * without a title or label hit are dropped, and a label-only hit keeps the
+ * without a display-title or label hit are dropped, and a label-only hit keeps the
  * bare project row.
  * @param list - sessions list snapshot.
  * @param view - local expansion arrays and search query.

packages/client/ui-sidebar/tests/apply.spec.tsx

@@ -23,7 +23,7 @@ async function bench() {
   await ctx.plugin(SlotsService).await()
   const list = createSnapshotStore<SessionListState>({
     ids: [sid('a')],
-    byId: { [sid('a')]: { id: sid('a'), title: 'alpha', cwd: '/proj', running: false, updatedAt: 1 } },
+    byId: { [sid('a')]: { id: sid('a'), title: 'alpha', displayTitle: 'alpha', cwd: '/proj', running: false, updatedAt: 1 } },
     current: undefined,
   })
   const sessions = { list, create: vi.fn(async () => sid('minted')), open: vi.fn() }

packages/client/ui-sidebar/tests/sidebar-root.spec.tsx

@@ -38,6 +38,7 @@ function summary(init: SummaryInit): SessionSummary {
   const s: SessionSummary = {
     id: sid(init.id),
     title: init.title ?? init.id,
+    displayTitle: init.title ?? init.id,
     running: init.running ?? false,
     updatedAt: init.updatedAt ?? 0,
   }

packages/client/ui-sidebar/tests/tree.spec.ts

@@ -11,6 +11,7 @@ const sid = (s: string) => s as SessionId
 interface SummaryInit {
   id: string
   title?: string
+  displayTitle?: string
   cwd?: string
   parentId?: string
   running?: boolean
@@ -20,10 +21,11 @@ interface SummaryInit {
 function summary(init: SummaryInit): SessionSummary {
   const s: SessionSummary = {
     id: sid(init.id),
-    title: init.title ?? init.id,
+    displayTitle: init.displayTitle ?? init.title ?? init.id,
     running: init.running ?? false,
     updatedAt: init.updatedAt ?? 0,
   }
+  if (init.title !== undefined) s.title = init.title
   if (init.cwd !== undefined) s.cwd = init.cwd
   if (init.parentId !== undefined) s.parentId = sid(init.parentId)
   return s
@@ -211,6 +213,15 @@ describe('deriveRows search', () => {
     const rows = deriveRows(list, view({ query: '   ' }))
     expect(rows.every(r => r.type === 'project')).toBe(true)
   })
+
+  it('matches the effective display title when no durable title is available', () => {
+    const fallback = listOf(summary({ id: 'raw-id', displayTitle: 'project fallback', cwd: '/elsewhere' }))
+    const rows = deriveRows(fallback, view({ query: 'fallback' }))
+    expect(rows).toEqual([
+      expect.objectContaining({ type: 'project', key: '/elsewhere' }),
+      expect.objectContaining({ type: 'session', id: 'raw-id', title: 'project fallback' }),
+    ])
+  })
 })
 
 describe('formatRelativeTime', () => {

packages/client/web/README.md

@@ -4,6 +4,8 @@ Web shell library: `bootWebShell(el, seams?)` mounts the whole client — loader
 
 The optional `seams` parameter forwards the client loader's `fetchBundle`/`executeBundle` transport overrides (`BootSeams`); production callers omit it — it exists for test environments where `<script>` execution cannot reach the page context (jsdom).
 
+The shell owns browser-title projection. With a selected session carrying a durable title, it renders `<session title> — <existing HTML title>` and reacts to later title revisions; no selection or a selected untitled session preserves the existing title, and shell unmount restores it. The existing HTML title remains the configurable product suffix.
+
 ## Model Experience
 
 None, as the entry shell boots the browser plugin tree; nothing here reaches a model request.

packages/client/web/src/DocumentTitle.tsx

@@ -0,0 +1,22 @@
+import { useEffect, useRef } from 'react'
+
+/** Props for the shell-owned browser title projection. */
+export interface DocumentTitleProps {
+  /** Durable title of the selected session, or undefined for the product title. */
+  title?: string
+}
+
+/**
+ * Project the selected durable session title into the browser title and
+ * restore the shell's original product title when unmounted.
+ * @param props - selected session title projection.
+ * @returns no rendered content.
+ */
+export function DocumentTitle({ title }: DocumentTitleProps): null {
+  const original = useRef(document.title)
+  useEffect(() => {
+    document.title = title === undefined ? original.current : `${title} — ${original.current}`
+    return () => { document.title = original.current }
+  }, [title])
+  return null
+}

packages/client/web/src/app.tsx

@@ -6,6 +6,9 @@
  */
 import type { ReactNode } from 'react'
 import type { Context } from 'cordis'
+import type { SessionsService } from '@deepseek-ai/dsh-client-runtime/client'
+import { bindSnapshotSelector } from '@deepseek-ai/dsh-client-web-react'
+import { DocumentTitle } from './DocumentTitle.tsx'
 // Type-only: pulls the runtime's SlotMap declaration merge (the 'root' key) into this program.
 import type {} from '@deepseek-ai/dsh-client-runtime/client'
 
@@ -24,5 +27,20 @@ export interface AssemblyDeps {
  */
 export function buildRenderApp(deps: AssemblyDeps): () => ReactNode {
   const { ctx } = deps
-  return () => ctx.slots.renderSlot('root', {})
+  const sessions = ctx.get('sessions') as SessionsService | undefined
+  if (sessions === undefined) throw new Error('shell assembly: sessions service unavailable')
+  const useSessions = bindSnapshotSelector(sessions.list)
+  const SessionDocumentTitle = (): ReactNode => {
+    const title = useSessions((state) => {
+      const id = state.current
+      return id === undefined ? undefined : state.byId[id]?.title
+    })
+    return <DocumentTitle {...title === undefined ? {} : { title }} />
+  }
+  return () => (
+    <>
+      <SessionDocumentTitle />
+      {ctx.slots.renderSlot('root', {})}
+    </>
+  )
 }

packages/client/web/src/index.ts

@@ -8,4 +8,5 @@
 export { bootWebShell } from './boot.tsx'
 export { AppRoot, type AppRootProps } from './AppRoot.tsx'
 export { buildRenderApp, type AssemblyDeps } from './app.tsx'
+export { DocumentTitle, type DocumentTitleProps } from './DocumentTitle.tsx'
 export { seedModules } from './seed.ts'

packages/client/web/tests/boot.spec.tsx

@@ -39,7 +39,7 @@ window.DSHClientProxy.loadPlugin({
     return {
       apply: (ctx) => {
         ctx.plugin(SlotsService)
-        const list = createSnapshotStore({ ids: ['s1'], byId: { s1: { id: 's1', title: 'S1', running: false, updatedAt: 1 } }, current: 's1' })
+        const list = createSnapshotStore({ ids: ['s1'], byId: { s1: { id: 's1', title: 'S1', displayTitle: 'S1', running: false, updatedAt: 1 } }, current: 's1' })
         ctx.provide('sessions', {
           list,
           cell: (id) => (id === 's1' ? { sessionId: 's1', session: { getSnapshot: () => ({}), subscribe: () => () => {} } } : undefined),
@@ -134,6 +134,7 @@ afterEach(() => {
   delete win.__TEST_RUNTIME_STORE__
   document.body.innerHTML = ''
   document.head.querySelectorAll('script').forEach((s) => { s.remove() })
+  document.title = ''
 })
 
 /** Hand the real runtime surface to the stub bundle (runtime is not a seeded library). */
@@ -147,6 +148,7 @@ describe('bootWebShell (real loader + real script execution)', () => {
     win.__DSH_BOOT__ = { plugins: bootPlugins() }
     seedSlotsService()
     const el = mountPoint()
+    document.title = 'DeepSeek Harness'
     let unmount: (() => void) | undefined
     act(() => { unmount = bootWebShell(el, seams(fakeBundles())) })
     expect(el.textContent).toContain('HARNESS')
@@ -155,9 +157,11 @@ describe('bootWebShell (real loader + real script execution)', () => {
     await flushLoader()
     expect(el.querySelector('[data-testid="fake-frame"]')).not.toBeNull()
     expect(el.textContent).not.toContain('HARNESS')
+    expect(document.title).toBe('S1 — DeepSeek Harness')
 
     act(() => { unmount!() })
     expect(el.childElementCount).toBe(0)
+    expect(document.title).toBe('DeepSeek Harness')
   })
 
   it('store seat round-trips through the entry props (useStore + actions)', async () => {
@@ -218,6 +222,9 @@ describe('buildRenderApp — assembly contract', () => {
     const ctx = new Context()
     const fiber = ctx.plugin(SlotsService)
     await fiber.await()
+    ctx.provide('sessions', {
+      list: createSnapshotStore({ ids: [], byId: {}, current: undefined }),
+    })
     const renderApp = buildRenderApp({ ctx, requireModule: () => undefined })
     expect(renderApp).toBeTypeOf('function')
     // No renderer installed: the one-line shell must surface the boot-order error.

packages/client/web/tests/document-title.spec.tsx

@@ -0,0 +1,28 @@
+// @vitest-environment jsdom
+import { afterEach, describe, expect, it } from 'vitest'
+import { cleanup, render } from '@testing-library/react'
+import { DocumentTitle } from '../src/DocumentTitle.tsx'
+
+afterEach(() => {
+  cleanup()
+  document.title = ''
+})
+
+describe('DocumentTitle', () => {
+  it('preserves the product title without a durable title and restores it on unmount', () => {
+    document.title = 'DeepSeek Harness'
+    const mounted = render(<DocumentTitle />)
+    expect(document.title).toBe('DeepSeek Harness')
+
+    mounted.rerender(<DocumentTitle title="First title" />)
+    expect(document.title).toBe('First title — DeepSeek Harness')
+
+    mounted.rerender(<DocumentTitle title="Revised title" />)
+    expect(document.title).toBe('Revised title — DeepSeek Harness')
+
+    mounted.rerender(<DocumentTitle />)
+    expect(document.title).toBe('DeepSeek Harness')
+    mounted.unmount()
+    expect(document.title).toBe('DeepSeek Harness')
+  })
+})

packages/cordis/tool-cordis/src/api-catalog.ts

@@ -1455,7 +1455,7 @@ export const TYPE_API: readonly TypeApiEntry[] = [
   },
   {
     name: 'GenerateOptions',
-    declaration: 'export interface GenerateOptions {\n    provider: string;\n    model: string;\n    messages: Message[];\n    system?: string;\n    tools?: ToolSchema[];\n    temperature?: number;\n    maxTokens?: number;\n    stop?: string[];\n    signal?: AbortSignal;\n    sessionId?: Branded<\'SessionId\'>;\n    purpose?: \'compaction\';\n}',
+    declaration: 'export interface GenerateOptions {\n    provider: string;\n    model: string;\n    messages: Message[];\n    system?: string;\n    tools?: ToolSchema[];\n    temperature?: number;\n    maxTokens?: number;\n    stop?: string[];\n    signal?: AbortSignal;\n    sessionId?: Branded<\'SessionId\'>;\n    purpose?: \'compaction\' | \'session-title\';\n}',
   },
   {
     name: 'GenericCallView',

packages/host/apiproxy/README.md

@@ -8,6 +8,8 @@ Wire messages form a four-quadrant discriminated union — who initiates × requ
 
 The layering/protocol decisions are recorded in the [GUI layering and RPC protocol RFC](../../../.agents/notes/implemented/architecture/2026-07-19-gui-layering-and-rpc-protocol.md); the browser-side consumption architecture in the [web client architecture RFC](../../../.agents/notes/implemented/architecture/2026-07-19-gui-web-client-architecture.md).
 
+The mux stream projects the latest log-backed title as a validated `session/title` control frame after each attached-session subscription baseline and immediately after the corresponding live raw title event. This projection does not add titles to `session.list`; cold sessions remain metadata-only there until opening or resuming attaches their logs.
+
 ## Carrier layer (`/client` + root)
 
 `AbstractApiClient` holds every protocol invariant — rpcId minting, envelope wrap/unwrap, zod parsing, SSE frame decoding, unary timeout, microtask-batched envelope observation (`subscribeEnvelopes`) — while platform subclasses supply only the `doFetch` transport aspect. `InProcessApiClient` over `toFetchHandler(api)` is the isomorphic point: the full wire serialization/validation path with no network, used by `dsh -p` headless.

packages/host/apiproxy/src/api/events.schema.ts

@@ -26,6 +26,7 @@ export const askUserQuestionItemSchema = z.object({
 export const muxFrameSchema = z.discriminatedUnion('type', [
   z.object({ type: z.literal('session/event'), sessionId: sessionIdSchema, event: sessionEventSchema, view: toolEventViewSchema.optional() }),
   z.object({ type: z.literal('session/subscribed'), sessionId: sessionIdSchema, lastSeq: z.number().int() }),
+  z.object({ type: z.literal('session/title'), sessionId: sessionIdSchema, title: z.string().min(1), eventSeq: z.number().int().nonnegative(), updatedAt: z.number() }),
   z.object({ type: z.literal('approval/requested'), sessionId: sessionIdSchema, approvalId: approvalRequestIdSchema, toolName: z.string(), callId: z.string().optional(), reason: z.string().optional() }),
   z.object({ type: z.literal('approval/resolved'), sessionId: sessionIdSchema, approvalId: approvalRequestIdSchema, outcome: z.union([z.literal('allowed-once'), z.literal('rejected'), z.literal('cancelled'), z.literal('unavailable')]) }),
   // Non-empty by wire contract: the user-interaction service rejects empty

packages/host/apiproxy/src/api/events.ts

@@ -33,8 +33,9 @@ export type ToolEventView =
 export interface EventsApi {
   /**
    * All-session aggregated mux stream. On open, emits a subscribed control frame for every
-   * attached session and replays each session's still-pending approval/question requested
-   * frames (rpcId reused verbatim — the refresh-recovery baseline).
+   * attached session followed by its optional latest title snapshot, then replays each
+   * session's still-pending approval/question requested frames (rpcId reused verbatim — the
+   * refresh-recovery baseline).
    * since: resume seam, unimplemented in v1 (ignored if passed); reconnection = reopen the
    * stream + refetch history.
    */
@@ -54,6 +55,7 @@ export interface EventsApi {
 export type MuxFrame =
   | { type: 'session/event'; sessionId: SessionId; event: SessionEvent; view?: ToolEventView }
   | { type: 'session/subscribed'; sessionId: SessionId; lastSeq: number }
+  | { type: 'session/title'; sessionId: SessionId; title: string; eventSeq: number; updatedAt: number }
   | { type: 'approval/requested'; sessionId: SessionId; approvalId: ApprovalRequestId; toolName: string; callId?: CallId; reason?: string }
   | { type: 'approval/resolved'; sessionId: SessionId; approvalId: ApprovalRequestId; outcome: ApprovalOutcome }
   | { type: 'question/requested'; sessionId: SessionId; questions: AskUserQuestionItem[] }

packages/host/apiproxy/tests/rpc-schemas.spec.ts

@@ -124,6 +124,7 @@ describe('events frame schemas', () => {
     const frames = [
       { type: 'session/event', sessionId: 's', event: { type: 't', seq: 0, time: 1, data: null } },
       { type: 'session/subscribed', sessionId: 's', lastSeq: -1 },
+      { type: 'session/title', sessionId: 's', title: 'Durable title', eventSeq: 2, updatedAt: 3 },
       { type: 'approval/requested', sessionId: 's', approvalId: 'a', toolName: 'bash', callId: 'c', reason: 'r' },
       { type: 'approval/resolved', sessionId: 's', approvalId: 'a', outcome: 'allowed-once' },
       { type: 'question/requested', sessionId: 's', questions: [{ id: 'q', question: 'Q?', options: [{ label: 'L' }], multiSelect: true }] },
@@ -132,6 +133,13 @@ describe('events frame schemas', () => {
     ]
     for (const frame of frames) expect(muxFrameSchema.parse(frame)).toMatchObject({ type: frame.type })
     expect(() => muxFrameSchema.parse({ type: 'unknown/frame' })).toThrow()
+    for (const invalid of [
+      { type: 'session/title', sessionId: 's', title: '', eventSeq: 0, updatedAt: 1 },
+      { type: 'session/title', sessionId: 's', title: 'x', eventSeq: -1, updatedAt: 1 },
+      { type: 'session/title', sessionId: 's', title: 'x', eventSeq: 0.5, updatedAt: 1 },
+      { type: 'session/title', sessionId: 's', title: 'x', eventSeq: 0, updatedAt: 'now' },
+      { type: 'session/title', sessionId: 's', title: 'x', eventSeq: 0, updatedAt: Number.NaN },
+    ]) expect(() => muxFrameSchema.parse(invalid)).toThrow()
     expect(askUserQuestionItemSchema.parse({ id: 'q', question: 'Q?' }).id).toBe('q')
   })
 

packages/host/runtime/README.md

@@ -1,6 +1,6 @@
 # @deepseek-ai/dsh-host-runtime
 
-Host runtime assembly for `dsh`: `bootHost` composes the core plugin spine (LLM service + DeepSeek adapter, sessions with JSONL persistence, system prompt, tools, agents, agent loop, workspace instructions, local bash, and the provider-neutral user-interaction service), `createApiProxy` implements the [`dsh-host-apiproxy`](../apiproxy/README.md) contract over that composition, and `startHost` is the one-step shell seam returning `{ api, handler, defaults, ctx, dispose }`.
+Host runtime assembly for `dsh`: `bootHost` composes the core plugin spine (LLM service + DeepSeek adapter, sessions with JSONL persistence and immediate fallback titles, optional first-message model summaries, system prompt, tools, agents, agent loop, workspace instructions, local bash, and the provider-neutral user-interaction service), `createApiProxy` implements the [`dsh-host-apiproxy`](../apiproxy/README.md) contract over that composition, and `startHost` is the one-step shell seam returning `{ api, handler, defaults, ctx, dispose }`.
 
 Which plugins mount and with what defaults is decided only here — shells must not `ctx.plugin` to alter the assembly. `RunningHost.ctx` is a formal seam with exactly two sanctioned uses: mounting protocol front-door plugins (e.g. a future `dsh acp`) and headless session-event subscription; consuming clients must not bypass `api` through it.
 
@@ -12,6 +12,9 @@ Which plugins mount and with what defaults is decided only here — shells must
 | `workspaceContext` | (required) | [`AGENTS.md`/`CLAUDE.md` loader](../../context/workspace-context/README.md) config with an explicit `maxBytes`, or `false` to disable it. |
 | `provider` | `'deepseek'` | Default provider route injected as agentOptions on create/resume and reported by `host.describe`. |
 | `model` | `'deepseek-v4-flash'` | Default model id, same single source as `provider`. |
+| `cwd` | `process.cwd()` | Default project directory for a session whose create request omits `cwd`. |
+| `sessionTitle` | 5 words / 40 fallback bytes / 80 accepted bytes | Deterministic fallback and accepted-title limits. |
+| `sessionTitleLlm` | disabled | `true` enables the 5-word / 10-CJK-character, 4,096-input-byte, 64-output-token, 60-second first-message policy; an explicit config overrides it. An omitted route inherits the logged main-request provider and model. |
 
 ## ApiProxy implementation notes
 
@@ -19,11 +22,11 @@ Unary methods take the narrow `RpcRequest<P>` and echo `request.rpcId`; a prompt
 
 ## Model Experience
 
-Indirectly, through the model-facing plugins bootHost mounts and the provider/model defaults injected into created and resumed agents. When `workspaceContext` is enabled, each agent-loop instance freezes the applicable workspace instructions into its logged request prefix; the owning package documents the exact [model-visible framing](../../context/workspace-context/README.md#prompt-shape).
+Indirectly, through the non-blocking first-message title request owned by [`dsh-session-title-llm`](../../session-title/session-title-llm/README.md) when `sessionTitleLlm` is enabled, the provider/model defaults injected into created and resumed agents, the other model-facing plugins `bootHost` mounts, and the logged [workspace-instruction prefix](../../context/workspace-context/README.md#prompt-shape) when `workspaceContext` is enabled.
 
 #### KV Cache effect
 
-No direct invalidation; the mounted model-facing plugins own their request-prefix changes.
+No main-request invalidation; when enabled, the auxiliary title request has its own cache behavior and leaves the conversation prefix unchanged.
 
 ## Known Limitations and Deferred Work
 

packages/host/runtime/package.json

@@ -50,6 +50,8 @@
     "@deepseek-ai/dsh-session": "workspace:^",
     "@deepseek-ai/dsh-session-persistence": "workspace:^",
     "@deepseek-ai/dsh-session-persistence-jsonl": "workspace:^",
+    "@deepseek-ai/dsh-session-title": "workspace:^",
+    "@deepseek-ai/dsh-session-title-first-message-llm": "workspace:^",
     "@deepseek-ai/dsh-skill": "workspace:^",
     "@deepseek-ai/dsh-skill-local": "workspace:^",
     "@deepseek-ai/dsh-spill-local": "workspace:^",

packages/host/runtime/src/api-proxy.ts

@@ -10,6 +10,7 @@ import type { Agent, AgentStatus } from '@deepseek-ai/dsh-agent'
 import type { ContentBlock, MessageSource } from '@deepseek-ai/dsh-llm'
 import type { JsonValue, Session, SessionEvent, SessionHeader, SessionId } from '@deepseek-ai/dsh-session'
 import type { SessionPersistence } from '@deepseek-ai/dsh-session-persistence'
+import { foldSessionTitle } from '@deepseek-ai/dsh-session-title'
 import type {
   ApiProxy, HistoryEntry, HostFrame, MuxFrame, QuestionResponsePayload, SessionSummary, ToolEventView,
 } from '@deepseek-ai/dsh-host-apiproxy/api'
@@ -109,6 +110,28 @@ function frame<F>(payload: F): RpcRequest<F> {
   return { rpcId: RpcId(randomUUID()), payload }
 }
 
+type SessionTitleFrame = Extract<MuxFrame, { type: 'session/title' }>
+
+/** Project the latest durable title without exposing title-generation policy. */
+function titleFrame(session: Session): SessionTitleFrame | undefined {
+  const title = foldSessionTitle(session.events)
+  if (title === undefined) return undefined
+  return {
+    type: 'session/title',
+    sessionId: session.id,
+    title: title.title,
+    eventSeq: title.eventSeq,
+    updatedAt: title.updatedAt,
+  }
+}
+
+/** Queue the subscription baseline followed by its optional title snapshot. */
+function subscribeSession(queue: FrameQueue<RpcRequest<MuxFrame>>, session: Session): void {
+  queue.push(frame({ type: 'session/subscribed', sessionId: session.id, lastSeq: session.seq - 1 }))
+  const title = titleFrame(session)
+  if (title !== undefined) queue.push(frame(title))
+}
+
 /** SessionSummary projection for attached (in-memory) sessions. */
 function summarize(session: Session, running: boolean): SessionSummary {
   return {
@@ -455,7 +478,7 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
         const queue = new FrameQueue<RpcRequest<MuxFrame>>()
         muxQueues.add(queue)
         for (const session of ctx.sessions.list()) {
-          queue.push(frame({ type: 'session/subscribed', sessionId: session.id, lastSeq: session.seq - 1 }))
+          subscribeSession(queue, session)
         }
         for (const pending of pendingQuestions.values()) {
           queue.push({
@@ -487,9 +510,13 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
             const view = viewFor(ctx, event, callId =>
               openCalls.get(session.id)?.get(callId) ?? backscanArgs(session.events, callId))
             queue.push(frame({ type: 'session/event', sessionId: session.id, event, ...view === undefined ? {} : { view } }))
+            if (event.type === 'session/title') {
+              // The accepted raw event is already in session.events, so the fold must find it.
+              queue.push(frame(titleFrame(session) as SessionTitleFrame))
+            }
           }),
           ctx.on('session/created', (session: Session) => {
-            queue.push(frame({ type: 'session/subscribed', sessionId: session.id, lastSeq: session.seq - 1 }))
+            subscribeSession(queue, session)
           }),
           ctx.on('session/disposed', (session: Session) => {
             openCalls.delete(session.id)

packages/host/runtime/src/boot.ts

@@ -8,6 +8,9 @@ import { Context } from 'cordis'
 import Timer from '@cordisjs/plugin-timer'
 import LlmService from '@deepseek-ai/dsh-llm'
 import SessionStore from '@deepseek-ai/dsh-session'
+import SessionTitleService, { type Config as SessionTitleConfig } from '@deepseek-ai/dsh-session-title'
+import * as SessionTitleFirstMessageLlm from '@deepseek-ai/dsh-session-title-first-message-llm'
+import type { Config as SessionTitleLlmConfig } from '@deepseek-ai/dsh-session-title-first-message-llm'
 import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
 import ToolRegistry from '@deepseek-ai/dsh-tools'
 import AgentRegistry from '@deepseek-ai/dsh-agent'
@@ -40,6 +43,22 @@ import SpillLocal from '@deepseek-ai/dsh-spill-local'
 import * as spillPolicy from '@deepseek-ai/dsh-spill-policy'
 import UserInteractionService from '@deepseek-ai/dsh-user-interaction'
 
+/** Default deterministic title policy for sessions created through the host. */
+const DEFAULT_SESSION_TITLE_CONFIG: SessionTitleConfig = {
+  fallbackMaxWords: 5,
+  fallbackMaxBytes: 40,
+  maxTitleBytes: 80,
+}
+
+/** Default first-message model-title policy for sessions created through the host. */
+const DEFAULT_SESSION_TITLE_LLM_CONFIG: SessionTitleLlmConfig = {
+  targetWords: 5,
+  targetCjkCharacters: 10,
+  maxInputBytes: 4_096,
+  maxOutputTokens: 64,
+  timeoutMs: 60_000,
+}
+
 /** Options for bootHost — the assembly-layer composition knobs. */
 export interface BootHostOptions {
   /** Root directory for JSONL session persistence. */
@@ -50,6 +69,10 @@ export interface BootHostOptions {
   provider?: string
   /** Default model id (defaults to 'deepseek-v4-flash', matching the demos). */
   model?: string
+  /** Deterministic fallback-title limits. */
+  sessionTitle?: SessionTitleConfig
+  /** Opt-in first-message model-title policy; `true` selects host defaults and an explicit config overrides them. */
+  sessionTitleLlm?: true | SessionTitleLlmConfig
   /**
    * Default project directory for sessions created without an explicit cwd
    * (defaults to the host process working directory). A session's cwd is its
@@ -93,6 +116,13 @@ export async function bootHost(options: BootHostOptions): Promise<HostHandle> {
   await ctx.plugin(Timer)
   await ctx.plugin(LlmService)
   await ctx.plugin(SessionStore)
+  await ctx.plugin(SessionTitleService, options.sessionTitle ?? DEFAULT_SESSION_TITLE_CONFIG)
+  if (options.sessionTitleLlm !== undefined) {
+    await ctx.plugin(
+      SessionTitleFirstMessageLlm,
+      options.sessionTitleLlm === true ? DEFAULT_SESSION_TITLE_LLM_CONFIG : options.sessionTitleLlm,
+    )
+  }
   await ctx.plugin(SystemPrompt, { persona: '' })
   await ctx.plugin(ToolRegistry)
   await ctx.plugin(UserInteractionService)

packages/host/runtime/tests/host-runtime.spec.ts

@@ -8,6 +8,8 @@ import { agentEvents } from '@deepseek-ai/dsh-agent'
 import type { GenerateOptions, StreamChunk } from '@deepseek-ai/dsh-llm'
 import { LlmAdapter } from '@deepseek-ai/dsh-llm'
 import type { SessionId } from '@deepseek-ai/dsh-session'
+import type { Config as SessionTitleConfig } from '@deepseek-ai/dsh-session-title'
+import type { Config as SessionTitleLlmConfig } from '@deepseek-ai/dsh-session-title-first-message-llm'
 import type { HostFrame, MuxFrame } from '@deepseek-ai/dsh-host-apiproxy/api'
 import type { RpcRequest, RpcResponse } from '@deepseek-ai/dsh-host-apiproxy/api/rpc'
 import { RpcId } from '@deepseek-ai/dsh-host-apiproxy/api/rpc'
@@ -22,6 +24,10 @@ class ScriptedAdapter extends LlmAdapter {
   }
 
   async * stream(options: GenerateOptions): AsyncIterable<StreamChunk> {
+    if ((options.tools?.length ?? 0) === 0) {
+      yield * textResponse('Durable append-only session titles')
+      return
+    }
     this.requests.push(options)
     const entry = this.script.shift()
     if (!entry) throw new Error('ScriptedAdapter: script exhausted')
@@ -68,6 +74,21 @@ function expectOk<T>(response: RpcResponse<T>): T {
   return response.result.value
 }
 
+async function nextMux(iterator: AsyncIterator<RpcRequest<MuxFrame>>): Promise<RpcRequest<MuxFrame>> {
+  const next = await iterator.next()
+  if (next.done === true) throw new Error('mux ended before the expected frame')
+  return next.value
+}
+
+/** Durably append a title event without mounting title-generation policy. */
+function appendTitle(ctx: Context, agent: Agent, title: string) {
+  return ctx.sessions.appendOutOfBand(agent.session, 'session/title', {
+    title,
+    messageSeqs: [1],
+    source: { kind: 'fallback' },
+  }, { kind: 'session-title' })
+}
+
 let host: RunningHost | undefined
 
 beforeEach(() => {
@@ -80,13 +101,19 @@ afterEach(async () => {
   vi.unstubAllEnvs()
 })
 
-async function boot(script: (StreamChunk[] | 'hang')[] = []): Promise<RunningHost> {
+async function boot(
+  script: (StreamChunk[] | 'hang')[] = [],
+  sessionTitle?: SessionTitleConfig,
+  sessionTitleLlm?: true | SessionTitleLlmConfig,
+): Promise<RunningHost> {
   host = await startHost({
     boot: {
       persistenceRoot: mkdtempSync(join(tmpdir(), 'dsh-host-runtime-')),
       workspaceContext: false,
       provider: 'scripted',
       model: 'test-model',
+      ...(sessionTitle === undefined ? {} : { sessionTitle }),
+      ...(sessionTitleLlm === undefined ? {} : { sessionTitleLlm }),
     },
   })
   host.ctx.llm.registerAdapter(['scripted'], new ScriptedAdapter(script))
@@ -161,6 +188,23 @@ describe('bootHost / startHost', () => {
     expect(requestText).toContain('Instructions from: AGENTS.md')
     expect(requestText).toContain('host-workspace-context-probe')
   })
+
+  it('keeps model title generation disabled when sessionTitleLlm is omitted', async () => {
+    const running = await boot([textResponse('pong')])
+    const { api, ctx } = running
+    const { sessionId } = expectOk(await api.sessions.create(request({})))
+    const agent = ctx.agents.get(sessionId) as Agent
+    const idle = waitForIdle(ctx, agent)
+    expectOk(await api.sessions.prompt(request({
+      sessionId,
+      mode: 'queue' as const,
+      content: [{ type: 'text' as const, text: 'Explain durable session titles.' }],
+    })))
+    await idle
+
+    expect((await ctx.sessionTitle.refresh(agent.session))?.source).toEqual({ kind: 'fallback' })
+    expect(agent.session.events.some(event => event.type === 'session/title-llm-request')).toBe(false)
+  })
 })
 
 describe('host.describe', () => {
@@ -190,6 +234,94 @@ describe('sessions.create / list', () => {
 })
 
 describe('sessions.prompt / cancel', () => {
+  it.each([
+    { name: 'host default', config: true, target: '5 words', maxTokens: 64 },
+    {
+      name: 'configured policy',
+      config: {
+        targetWords: 3,
+        targetCjkCharacters: 8,
+        maxInputBytes: 2_048,
+        maxOutputTokens: 24,
+        timeoutMs: 2_000,
+      },
+      target: '3 words',
+      maxTokens: 24,
+    },
+  ] satisfies {
+    name: string
+    config: true | SessionTitleLlmConfig
+    target: string
+    maxTokens: number
+  }[])('replaces the fallback with a model-backed first-message title using the $name', async ({ config, target, maxTokens }) => {
+    const modelTitle = 'Durable append-only session titles'
+    const running = await boot([textResponse('pong')], undefined, config)
+    const { api, ctx } = running
+    const { sessionId } = expectOk(await api.sessions.create(request({})))
+    const agent = ctx.agents.get(sessionId) as Agent
+    const idle = waitForIdle(ctx, agent)
+    expectOk(await api.sessions.prompt(request({
+      sessionId,
+      mode: 'queue' as const,
+      content: [{ type: 'text' as const, text: 'Explain why append-only logs make session titles durable.' }],
+    })))
+    await idle
+
+    await vi.waitFor(() => {
+      expect(agent.session.events.filter(event => event.type === 'session/title').map(event => event.data))
+        .toEqual([
+          {
+            title: 'Explain why append-only logs make',
+            messageSeqs: [1],
+            source: { kind: 'fallback' },
+          },
+          {
+            title: modelTitle,
+            messageSeqs: [1],
+            source: {
+              kind: 'provider',
+              provider: 'session-title-first-message-llm',
+              model: { provider: 'scripted', model: 'test-model' },
+            },
+          },
+        ])
+    })
+    const titleRequest = agent.session.events.find(event => event.type === 'session/title-llm-request')
+    expect(titleRequest?.data.system).toContain(target)
+    expect(titleRequest?.data.maxTokens).toBe(maxTokens)
+  })
+
+  it.each([
+    { name: 'host default', config: undefined, expected: 'Show the Web UI durable' },
+    {
+      name: 'configured limit',
+      config: { fallbackMaxWords: 2, fallbackMaxBytes: 40, maxTitleBytes: 80 },
+      expected: 'Show the',
+    },
+  ] satisfies { name: string; config: SessionTitleConfig | undefined; expected: string }[])(
+    'logs a durable fallback title with the $name',
+    async ({ config, expected }) => {
+      const running = await boot([textResponse('pong')], config)
+      const { api, ctx } = running
+      const { sessionId } = expectOk(await api.sessions.create(request({})))
+      const agent = ctx.agents.get(sessionId) as Agent
+      const idle = waitForIdle(ctx, agent)
+      expectOk(await api.sessions.prompt(request({
+        sessionId,
+        mode: 'queue' as const,
+        content: [{ type: 'text' as const, text: 'Show the Web UI durable session title' }],
+      })))
+      await idle
+
+      const title = agent.session.events.find(event => event.type === 'session/title')
+      expect(title?.data).toEqual({
+        title: expected,
+        messageSeqs: [1],
+        source: { kind: 'fallback' },
+      })
+    },
+  )
+
   it('queues a prompt whose rpcId rides into user/message, then the reply lands', async () => {
     const running = await boot([textResponse('pong')])
     const { api, ctx } = running
@@ -261,6 +393,7 @@ describe('sessions.history', () => {
     const idle = waitForIdle(first.ctx, agent)
     agent.send([{ type: 'text', text: 'save me' }])
     await idle
+    const titleEvent = await appendTitle(first.ctx, agent, 'Persisted title')
     await first.dispose()
 
     host = await startHost({
@@ -268,6 +401,8 @@ describe('sessions.history', () => {
     })
     host.ctx.llm.registerAdapter(['scripted'], new ScriptedAdapter([]))
     expect(host.ctx.agents.get(sessionId)).toBeUndefined()
+    const abort = new AbortController()
+    const mux = host.api.events.mux(request({}), abort.signal)[Symbol.asyncIterator]()
     const [a, b] = await Promise.all([
       host.api.sessions.history(request({ sessionId })),
       host.api.sessions.history(request({ sessionId })),
@@ -278,6 +413,11 @@ describe('sessions.history', () => {
     }
     expect(host.ctx.agents.get(sessionId)).toBeDefined()
     expect(host.ctx.agents.list()).toHaveLength(1)
+    expect((await nextMux(mux)).payload).toMatchObject({ type: 'session/subscribed', sessionId })
+    expect((await nextMux(mux)).payload).toEqual(expect.objectContaining({
+      type: 'session/title', sessionId, title: 'Persisted title', eventSeq: titleEvent.seq,
+    }))
+    abort.abort()
   })
 
   it('errors session-not-found when resume fails, deduplicating concurrent resumes', async () => {
@@ -385,6 +525,43 @@ describe('events streams', () => {
     expect((await stream.next()).done).toBe(true)
   })
 
+  it('mux: projects durable titles after open baselines and immediately after live raw events', async () => {
+    const running = await boot()
+    const { api, ctx } = running
+    const { sessionId } = expectOk(await api.sessions.create(request({})))
+    const agent = ctx.agents.get(sessionId) as Agent
+    const initial = await appendTitle(ctx, agent, 'Initial title')
+
+    const ac = new AbortController()
+    const stream = api.events.mux(request({}), ac.signal)[Symbol.asyncIterator]()
+    expect((await nextMux(stream)).payload).toMatchObject({ type: 'session/subscribed', sessionId })
+    expect((await nextMux(stream)).payload).toEqual(expect.objectContaining({
+      type: 'session/title', sessionId, title: 'Initial title', eventSeq: initial.seq, updatedAt: initial.time,
+    }))
+
+    const revised = await appendTitle(ctx, agent, 'Revised title')
+    let raw: RpcRequest<MuxFrame>
+    do raw = await nextMux(stream)
+    while (!(raw.payload.type === 'session/event' && raw.payload.event.type === 'session/title'))
+    expect(raw.payload).toMatchObject({ type: 'session/event', sessionId, event: { seq: revised.seq } })
+    expect((await nextMux(stream)).payload).toEqual(expect.objectContaining({
+      type: 'session/title', sessionId, title: 'Revised title', eventSeq: revised.seq, updatedAt: revised.time,
+    }))
+    ac.abort()
+  })
+
+  it('mux: emits no title control for untitled subscriptions', async () => {
+    const { api } = await boot()
+    const first = expectOk(await api.sessions.create(request({}))).sessionId
+    const ac = new AbortController()
+    const stream = api.events.mux(request({}), ac.signal)[Symbol.asyncIterator]()
+    expect((await nextMux(stream)).payload).toMatchObject({ type: 'session/subscribed', sessionId: first })
+
+    const second = expectOk(await api.sessions.create(request({}))).sessionId
+    expect((await nextMux(stream)).payload).toMatchObject({ type: 'session/subscribed', sessionId: second })
+    ac.abort()
+  })
+
   it('host: session lifecycle, status flips (disposed suppressed), and agent errors', async () => {
     const running = await boot([textResponse('x')])
     const { api, ctx } = running

packages/host/runtime/tsconfig.json

@@ -23,6 +23,12 @@
     {
       "path": "../../core/session"
     },
+    {
+      "path": "../../session-title/session-title"
+    },
+    {
+      "path": "../../session-title/session-title-first-message-llm"
+    },
     {
       "path": "../../core/system-prompt"
     },

packages/llm/llm-deepseek/README.md

@@ -32,7 +32,7 @@ The plugin registers the single provider route `deepseek`. A request selects it
 
 `reasoningEffort` is **omitted by default** — when unset, the `reasoning_effort` wire field is not sent and the server applies its own default for the model. The only accepted values are `high` and `max` (DeepSeek's official effort levels). It is meaningful only with thinking enabled (the provider default).
 
-`thinking`/`reasoningEffort` are adapter-level request defaults serialized as the official top-level `thinking: {type}` / `reasoning_effort` wire fields. They live in adapter config (not `GenerateOptions`) to keep the core vocabulary provider-neutral.
+`thinking`/`reasoningEffort` are adapter-level request defaults serialized as the official top-level `thinking: {type}` / `reasoning_effort` wire fields. They live in adapter config (not `GenerateOptions`) to keep the core vocabulary provider-neutral. A request with `GenerateOptions.purpose: 'session-title'` forces thinking disabled and omits `reasoning_effort`, reserving its bounded output for visible title text without changing conversation or compaction defaults.
 
 `streamIdleTimeoutMs` bounds each outstanding provider read, including the initial `fetch`, without counting time the consumer spends between chunks. One stable abort signal reaches the request and body reader for the whole call; expiry stops the transport and throws `LlmError('TIMEOUT')`, while an earlier caller abort throws `LlmError('ABORTED')`. The adapter makes exactly one provider request per `stream()` call; agent-level retry is a separate plugin policy.
 

packages/llm/llm-deepseek/src/serialize.ts

@@ -118,14 +118,18 @@ export function serializeRequest(options: GenerateOptions, defaults: RequestDefa
       parameters: tool.parameters,
     },
   }))
+  // A short title budget must produce visible text; conversation and
+  // compaction calls continue to inherit the adapter's thinking defaults.
+  const thinking = options.purpose === 'session-title' ? 'disabled' : defaults.thinking
+  const reasoningEffort = options.purpose === 'session-title' ? undefined : defaults.reasoningEffort
 
   return {
     model: options.model,
     messages,
     stream: true,
     stream_options: { include_usage: true },
-    ...defaults.thinking !== undefined ? { thinking: { type: defaults.thinking } } : {},
-    ...defaults.reasoningEffort !== undefined ? { reasoning_effort: defaults.reasoningEffort } : {},
+    ...thinking !== undefined ? { thinking: { type: thinking } } : {},
+    ...reasoningEffort !== undefined ? { reasoning_effort: reasoningEffort } : {},
     ...tools !== undefined && tools.length > 0 ? { tools } : {},
     ...options.temperature !== undefined ? { temperature: options.temperature } : {},
     ...options.maxTokens !== undefined ? { max_tokens: options.maxTokens } : {},

packages/llm/llm-deepseek/tests/serialize.spec.ts

@@ -180,6 +180,15 @@ describe('serializeRequest', () => {
     expect(wire.reasoning_effort).toBe('max')
   })
 
+  it('disables thinking for session-title requests without changing adapter defaults', () => {
+    const wire = serializeRequest(
+      request({ messages: history, purpose: 'session-title' }),
+      { thinking: 'enabled', reasoningEffort: 'max' },
+    )
+    expect(wire.thinking).toEqual({ type: 'disabled' })
+    expect(wire.reasoning_effort).toBeUndefined()
+  })
+
   it('omits thinking fields when unset (provider default applies)', () => {
     const wire = serializeRequest(request({ messages: history }))
     expect(wire.thinking).toBeUndefined()

packages/llm/llm/README.md

@@ -39,7 +39,7 @@ Streaming is a raw chunk protocol (`block-start`, `text-delta`, `reasoning-delta
 
 ### Call configuration (`call-config.ts`)
 
-`LlmCallConfig` is the provider + model + sampling scalars of one conversation's requests (`provider`, `model`, `temperature`, `maxTokens`, `stop` — each mapping 1:1 onto the same-named `GenerateOptions` field). It is per-conversation state recorded in the session log as part of the request header (see the dsh-session `request/header` events), never a silently-adjustable per-call knob: the `agent/request` waterfall proposes a replacement and the loop logs a real change. `callConfigEquals(a, b)` is the field-wise real-change detector; `deepFreeze(value)` is the ownership helper the loop applies to every built request before dispatch (`llm/stream` listeners and adapters read, never rewrite). `markAgentLoopRequest()` gives that exact object process-local loop provenance, and `isAgentLoopRequest()` lets observers distinguish it from independently logged auxiliary calls that may also be frozen and session-associated.
+`LlmCallConfig` is the provider + model + sampling scalars of one conversation's requests (`provider`, `model`, `temperature`, `maxTokens`, `stop` — each mapping 1:1 onto the same-named `GenerateOptions` field). It is per-conversation state recorded in the session log as part of the request header (see the dsh-session `request/header` events), never a silently-adjustable per-call knob: the `agent/request` waterfall proposes a replacement and the loop logs a real change. `callConfigEquals(a, b)` is the field-wise real-change detector; `deepFreeze(value)` is the ownership helper the loop applies to every built request before dispatch (`llm/stream` listeners and adapters read, never rewrite). `markAgentLoopRequest()` gives that exact object process-local loop provenance, and `isAgentLoopRequest()` lets observers distinguish it from independently logged auxiliary calls that may also be frozen and session-associated. `GenerateOptions.purpose` classifies logged auxiliary compaction and session-title calls so adapters can apply purpose-specific transport policy without changing ordinary conversation requests.
 
 ### App attribution (`attribution.ts`)
 

packages/llm/llm/src/types.ts

@@ -228,8 +228,8 @@ export interface GenerateOptions {
   sessionId?: Branded<'SessionId'>
   /**
    * Provider-neutral classification for an auxiliary model call. Adapters may
-   * map the purpose to model-hidden transport metadata. Ordinary conversation
-   * requests leave it unset.
+   * map the purpose to model-hidden transport metadata or purpose-specific
+   * generation policy. Ordinary conversation requests leave it unset.
    */
-  purpose?: 'compaction'
+  purpose?: 'compaction' | 'session-title'
 }

packages/session-title/session-title-llm/README.md

@@ -8,7 +8,7 @@ This package is a library, not a Cordis plugin. The provider plugins call `regis
 
 `provider` and `model` overrides are optional but must be supplied together as non-empty strings. Without that pair, the helper uses the exact provider/model route captured from the current session's logged `request/header`; an explicit refresh before any route exists therefore needs overrides. The helper measures the final JSON-framed user prompt, including seq fields, wrappers, and JSON escaping, against `maxInputBytes` before logging or dispatch instead of truncating it. Timeout and caller cancellation are rechecked while consuming the stream and after it completes, so a late successful result cannot be accepted even if an interceptor or adapter ignores abort. Malformed or empty output, tool calls, and non-stop finish reasons also reject; the session-title service decides whether that rejection is an automatic warning or an explicit caller failure.
 
-After route and input validation, the helper appends a log-only `session/title-llm-request` event before model dispatch. It contains the title-provider id, exact source seqs, route, system prompt, message list, and output-token cap used by the call. The append shares the title capability's per-session settlement queue, so a superseding request cannot collide with an earlier fallback, request record, or accepted-title flush. The dispatched envelope is deep-frozen to keep interceptors aligned with that record but deliberately lacks dsh-agent-loop's process-local request identity, so loop-only reconstruction observers do not compare it with the conversation header. A later model failure leaves that request record intact; validation failures that never become dispatchable requests do not create one. The event stays outside derived model history.
+After route and input validation, the helper appends a log-only `session/title-llm-request` event before model dispatch. It contains the title-provider id, exact source seqs, route, system prompt, message list, and output-token cap used by the call. The append shares the title capability's per-session settlement queue, so a superseding request cannot collide with an earlier fallback, request record, or accepted-title flush. The dispatched envelope is deep-frozen, carries `purpose: 'session-title'`, and deliberately lacks dsh-agent-loop's process-local request identity. Interceptors stay aligned with the record while loop-only reconstruction observers do not compare it with the conversation header. The DeepSeek adapter maps that purpose to thinking-disabled so the small output budget is reserved for visible title text; other adapters own their purpose-specific behavior. A later model failure leaves the request record intact; validation failures that never become dispatchable requests do not create one. The event stays outside derived model history.
 
 ## Configuration
 
@@ -33,7 +33,7 @@ The title model receives a fixed system instruction to return one concise unador
 
 #### Token effect
 
-The auxiliary request consumes tokens according to selected input size and `maxOutputTokens`. It is separate from the main agent request and does not add title text or framing to agent history.
+The auxiliary request consumes tokens according to selected input size and `maxOutputTokens`. It is separate from the main agent request and does not add title text or framing to agent history. DeepSeek title calls disable thinking; the main conversation retains its configured thinking mode.
 
 #### KV Cache effect
 

packages/session-title/session-title-llm/src/index.ts

@@ -261,6 +261,7 @@ export async function generateSessionTitleWithLlm(
     system,
     maxTokens: config.maxOutputTokens,
     sessionId: request.session.id,
+    purpose: 'session-title',
     signal: callDeadline.signal,
   })
   await appendSessionTitleOutOfBand(ctx, request.session, 'session/title-llm-request', {

packages/session-title/session-title-llm/tests/llm.spec.ts

@@ -156,6 +156,7 @@ describe('generateSessionTitleWithLlm', () => {
       model: 'current-model',
       maxTokens: 32,
       sessionId: providerRequest.session.id,
+      purpose: 'session-title',
     })
     expect(options.system).toContain('5 words')
     expect(options.system).toContain('10 CJK characters')

pnpm-lock.yaml

@@ -2084,6 +2084,12 @@ importers:
       '@deepseek-ai/dsh-session-persistence-jsonl':
         specifier: workspace:^
         version: link:../../session-persistence/session-persistence-jsonl
+      '@deepseek-ai/dsh-session-title':
+        specifier: workspace:^
+        version: link:../../session-title/session-title
+      '@deepseek-ai/dsh-session-title-first-message-llm':
+        specifier: workspace:^
+        version: link:../../session-title/session-title-first-message-llm
       '@deepseek-ai/dsh-skill':
         specifier: workspace:^
         version: link:../../skill/skill

vitest.snapshot.config.ts

@@ -42,6 +42,9 @@ export default defineConfig({
   test: {
     setupFiles: ['./scripts/test-invariants.ts'],
     include: [
+      // The assembled Web snapshot executes generated client bundles; source
+      // mode remains the zero-build path, while lib mode requires a prior build.
+      ...(process.env.DSH_EXAMPLE_MODE === 'lib' ? ['apps/web/tests/**/*.snapshot.ts'] : []),
       'examples/*/tests/**/*.snapshot.ts',
       'packages/sdk/*/tests/**/*.snapshot.ts',
       'packages/ui/tui/tests/**/*.snapshot.ts',