Merge remote-tracking branch 'origin/master' into codex/basic-session-search

# Conflicts: # apps/web/tests/snapshots/question-composer/answered.expected.md # packages/client/connection/tests/fake-api.ts # packages/client/runtime/README.i18n.yaml # packages/client/runtime/tests/fake-api.ts # packages/client/ui-workspace/README.i18n.yaml # packages/client/ui-workspace/README.md # packages/client/ui-workspace/README.zh.md # packages/client/ui-workspace/src/client/WorkspaceBrowser.tsx # packages/client/ui-workspace/tests/apply.spec.ts # packages/host/apiproxy/README.i18n.yaml # packages/host/apiproxy/README.md # packages/host/apiproxy/README.zh.md # packages/host/apiproxy/src/api-proxy.ts # packages/host/apiproxy/src/api/index.ts # packages/host/apiproxy/src/api/sessions.schema.ts # packages/host/apiproxy/src/fetch/client.ts # packages/host/apiproxy/src/fetch/handler.ts # packages/host/apiproxy/tests/fetch-carrier.spec.ts # packages/host/apiproxy/tests/rpc-schemas.spec.ts # packages/session-query/session-query/tests/search-helpers.spec.ts
2026-07-28 09:27:28 +08:00
parent cbe6293eec c49c0ba497
commit 05d4c19085
1288 changed files with 40508 additions and 19164 deletions
--- a/packages/host/apiproxy/README.i18n.yaml
+++ b/packages/host/apiproxy/README.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/host/apiproxy/README.md
-README.md: 31a41a945e11a610f2c67c0ccf89a4d2677a1067
-README.zh.md: b78f7b19b0bde51327f09f282ef84ab087fab25b
+README.md: 93ebca4628c1ebcb3649b0aeb849f2a94468b21e
+README.zh.md: 2c7141aaa8c6cc07027c738b4d14de5e6a389dfc
--- a/packages/host/apiproxy/README.md
+++ b/packages/host/apiproxy/README.md
@@ -12,12 +12,16 @@ The layering/protocol decisions are recorded in the [GUI layering and RPC protoc

 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.

+Session model routing is a session-domain contract. `session.models` returns the selected provider/model/reasoning target with provider-grouped advisory models, exact-route reasoning metadata, and provider-local lookup failures. `session.selectModel` validates the optional adapter-owned reasoning effort and replaces the complete target selected for the next prompt-assembly boundary. Catalog membership is not validation: an adapter may resolve an unlisted model, while an unavailable route or unsupported effort returns `model-unavailable`.
+
 Workspace and Session lists are separate reconnect baselines. `workspace.create` creates a unique name or adopts an existing directory, `workspace.delete` removes only the Workspace registration, `session.create` accepts an optional preallocated Session id, and `host/workspace-changed`, `host/workspace-removed`, plus `host/session-added` carry committed increments in either arrival order. Registration deletion preserves the directory and session logs; its Sessions remain in `session.list` and become Ungrouped. `SessionSummary.blank` and the `host/session-added` frame carry the derived zero-events bit: clients hide blank sessions and reuse them per workspace, flip blank on the first `host/session-status(running:true)`, and treat `session.list` as the reconnect authority; cold summaries are never blank because lazy persistence keeps never-appended sessions out of `list()`.

 `session.search` is a bounded content-search projection over the sessions visible through `session.list`. The gateway asks the optional `ctx.sessionQuery` service for globally ranked current-surface user, assistant, and steering matches, consumes that stream until it has at most 20 visible session/snippet pairs plus one lookahead, and revalidates every hit against the list-derived authorization set before returning it. Provider pages start at 20 hits; when a first-page request rejects that limit, the gateway probes 10, 5, 2, then 1 and retains the learned size for continuation and stale-generation restarts. Returned snippets contain at most 240 Unicode code points, and the response schema independently enforces that bound at each client boundary. Keeping the authorization set in Host memory avoids SQLite's variable ceiling for large valid corpora without weakening visibility or ranking.

 A stale continuation discards every partial result, deduplication entry, and cursor from that provider attempt, then restarts at the first page against the original list-derived visibility snapshot without discarding the learned provider page size. Limit probes and stale retries share the same limit of at most 100 provider calls (and therefore at most 2,000 inspected hits); a page larger than its requested limit, a repeated continuation cursor, or a still-unexhausted stream at that call budget fails closed as an `internal` business error. The carrier request signal cancels persistence listing, cold-summary collection, and every search call, including a limit or stale rejection observed concurrently with cancellation. A deployment without the service, or any unrecovered index/query failure, also returns an `internal` business error so clients can retain metadata-only matches.

+`host.pickDirectory` opens one native directory picker and returns its selected path, or `null` when the user cancels. Its host implementation invokes platform tools without a shell: `osascript` on macOS, an STA PowerShell `FolderBrowserDialog` on Windows, and Zenity with a KDialog fallback on Linux. The picker function is injectable for tests. This user-paced method is the sole unary call exempt from the default 30-second timeout; caller and connection aborts still propagate to the native process. The browser carrier separately restricts this privileged method to loopback, same-origin requests.
+
 `session.history` pages on message boundaries, and its tail page (no `beforeSeq`) carries two session-level extras the page window cannot supply: the in-flight partial's chunk events, and `todos` — the latest `todo/write` whole-list projection over the full log. Older pages omit `todos` because the projection is session-level, not per-page; a tail response that omits it means the whole log holds no `todo/write`, so clients read the absent field as the empty plan rather than as unchanged state.

 The `command.*` and `skill.*` domains expose the host command registry and skill catalog to clients. Every method addresses one session's agent by `sessionId` (a served session always has an Agent; `command.*` resumes cold sessions through the same path as `session.*`, while `skill.list` resolves the project root from the session header without touching the Agent registry). `command.execute` runs a slash-command line host-side and returns a detached result; the carrier's request signal cancels the running handler. `host/commands-changed` is the catalog invalidation frame: clients refetch `command.list` instead of diffing.
@@ -40,3 +44,4 @@ None; this package neither assembles nor sends a provider request.
 - **Reserved seams stay out of `RpcMethodMap`** — `session.fork`, `prompt.mode: 'inject'`, `task.list`, `host.listModels`, and a describe `hostInstanceId` are documented reservations; an unknown method fails loud at envelope parse rather than getting a not-implemented code.
 - **No protocol version field** — client and host ship together; `host.describe` gains a version negotiation field only when an independently released client exists.
 - **Search failures include provider diagnostics** — the gateway is a single-user local service. A carrier that exposes it to multiple users must replace internal search details with a public-safe diagnostic.
+- **Linux native picker requires desktop tooling** — `host.pickDirectory` reports an actionable error when neither Zenity nor KDialog is installed; it does not fall back to a custom or typed-path browser.
--- a/packages/host/apiproxy/README.zh.md
+++ b/packages/host/apiproxy/README.zh.md
@@ -12,12 +12,16 @@

 mux 流会在每个已附加会话的订阅基线之后，以及对应的实时原始标题事件之后，立即把基于日志的最新标题投影为经过校验的 `session/title` 控制帧。该投影不会把标题加入 `session.list`；冷会话在其中仍只有元数据，直到打开或恢复操作附加其日志。

+会话模型路由属于会话领域契约。`session.models` 返回选中的提供方／模型／推理（reasoning）目标，以及按提供方分组的建议性模型、精确路由推理元数据和逐提供方查询失败记录。`session.selectModel` 校验由适配器持有的可选推理强度，并替换将在下一提示词组装边界使用的完整目标。目录成员关系不构成校验：适配器可以解析未列出的模型，而不可用路由或不受支持的推理强度会返回 `model-unavailable`。
+
 Workspace 列表与 Session 列表是相互独立的重连基线。`workspace.create` 会创建唯一名称或接纳现有目录，`workspace.delete` 只移除 Workspace 注册记录，`session.create` 接受可选的预分配 Session id，`host/workspace-changed`、`host/workspace-removed` 与 `host/session-added` 则以任意到达顺序携带已提交的增量。删除注册记录会保留目录和会话日志；相关 Session 仍留在 `session.list` 中，并进入 Ungrouped。`SessionSummary.blank` 与 `host/session-added` 帧携带派生的零事件位：客户端隐藏空白会话并按 workspace 复用它们，在首个 `host/session-status(running:true)` 时翻转 blank，并以 `session.list` 作为重连权威；冷会话摘要永远不是空白：惰性持久化让从未追加过事件的会话根本不出现在 `list()` 中。

 `session.search` 是以 `session.list` 所列会话为范围的有界内容搜索投影。网关向可选的 `ctx.sessionQuery` 服务请求全局排序后的当前 surface user、assistant 和 steering（中途引导）匹配项，并持续消费该结果流，直到获得至多 20 个可见会话／snippet 对及一个前瞻项；返回前仍会依据从列表推导的授权集合重新校验每个命中。提供方分页初始请求 20 个命中；如果第一页请求因这一上限被拒绝，网关会依次探测 10、5、2、1，并在续传和陈旧世代重启中沿用探测所得的页面大小。返回的 snippet 最多包含 240 个 Unicode 码点，响应 schema 则会在每个客户端边界独立强制执行该上限。将授权集合保留在宿主内存中，可在不削弱可见性或排序的前提下避开有效大型语料库的 SQLite 变量上限。

 陈旧的续传会丢弃该提供方尝试中的所有部分结果、去重条目和游标，然后依据最初从列表推导的可见性快照从第一页重新开始，但不会丢弃探测所得的提供方页面大小。上限探测与陈旧重试共用最多 100 次提供方调用的限制（因此最多检查 2,000 个命中）；如果某页命中数超过其请求的上限、续传游标重复，或用尽该调用预算后结果流仍未耗尽，都会直接返回 `internal` 业务错误，不返回部分结果。载体请求信号可取消持久化列表枚举、冷会话摘要收集和每一次搜索调用；即使同时收到上限拒绝或陈旧拒绝，也以取消为准。部署若未挂载该服务，或索引／查询故障无法恢复，也会返回 `internal` 业务错误，以便客户端保留仅基于元数据的匹配项。

+`host.pickDirectory` 会打开一个原生目录选择器并返回选中的路径；用户取消时返回 `null`。宿主实现不经 shell 调用平台工具：macOS 使用 `osascript`，Windows 使用以 STA 模式运行的 PowerShell `FolderBrowserDialog`，Linux 使用 Zenity，并以 KDialog 作为回退。选择器函数可在测试中注入。该方法需等待用户完成操作，是唯一不受默认 30 秒超时限制的一元调用；调用方发出的中止信号和连接中止仍会传播至原生进程。浏览器载体另行将这一特权方法限制为仅接受来自回环地址的同源请求。
+
 `session.history` 按消息边界分页，其尾页（不带 `beforeSeq`）额外携带两项页窗口本身无法提供的会话级数据：进行中局部消息的 chunk 事件，以及 `todos`——整份日志上最后一次 `todo/write` 的整表投影。较早的页面不带 `todos`，因为该投影是会话级而非分页级的；尾页响应缺少该字段意味着整份日志中没有任何 `todo/write`，因此客户端要把缺失字段读作空计划，而不是读作「状态未变」。

 `command.*` 与 `skill.*` 领域向客户端暴露宿主命令注册表和技能目录。每个方法都通过 `sessionId` 寻址一个会话的 Agent（被服务的会话必有 Agent；`command.*` 经由与 `session.*` 相同的路径恢复冷会话，而 `skill.list` 从会话头解析项目根目录，不触碰 Agent 注册表）。`command.execute` 在宿主侧运行一条斜杠命令行并返回脱耦结果；载体的请求信号可取消正在运行的处理器。`host/commands-changed` 是目录失效帧：客户端重新拉取 `command.list` 而不是做差分。
@@ -40,3 +44,4 @@ Workspace 列表与 Session 列表是相互独立的重连基线。`workspace.cr
 - **预留 seam 不进入 `RpcMethodMap`**：`session.fork`、`prompt.mode: 'inject'`、`task.list`、`host.listModels` 和描述字段 `hostInstanceId` 都是已记录的预留项；未知方法会在信封解析时直接失败，而不会返回「尚未实现」错误码。
 - **没有协议版本字段**：客户端与宿主一同发布；只有出现独立发布的客户端后，`host.describe` 才会增加版本协商字段。
 - **搜索失败会包含提供方诊断信息**：网关是单用户本地服务。将其暴露给多名用户的载体必须用可安全公开的诊断信息替代内部搜索细节。
+- **Linux 原生选择器依赖桌面工具**：Zenity 和 KDialog 均未安装时，`host.pickDirectory` 会给出包含解决建议的错误提示；它不会回退到自定义目录浏览器，也不会要求用户手动输入路径。
--- a/packages/host/apiproxy/src/api-proxy.ts
+++ b/packages/host/apiproxy/src/api-proxy.ts
@@ -7,7 +7,12 @@ import { randomUUID } from 'node:crypto'
 import { mkdir, stat } from 'node:fs/promises'
 import { join } from 'node:path'
 import type { Context } from 'cordis'
-import type { Agent, AgentMessage, AgentMessageId, AgentStatus } from '@deepseek-ai/dsh-agent'
+import { installAgentLlmTarget } from '@deepseek-ai/dsh-agent'
+import type {
+  Agent, AgentLlmTarget, AgentLlmTargetRef, AgentMessage, AgentMessageId, AgentStatus,
+} from '@deepseek-ai/dsh-agent'
+import { ReasoningEffortId } from '@deepseek-ai/dsh-llm'
+import { errorChain } from '@deepseek-ai/dsh-llm'
 import type { ContentBlock, MessageSource } from '@deepseek-ai/dsh-llm'
 import type { JsonValue, Session, SessionEvent, SessionHeader, SessionId, TodoItem } from '@deepseek-ai/dsh-session'
 import type { SessionPersistence } from '@deepseek-ai/dsh-session-persistence'
@@ -21,8 +26,9 @@ import {
 // Type-only: brings the `ctx.tools` Context merge into this program (viewFor reads presenters).
 import type {} from '@deepseek-ai/dsh-tools'
 import type {
-  ApiProxy, HistoryEntry, HostFrame, MuxFrame, QuestionResponsePayload, SessionSearchItem,
-  SessionSummary, ToolEventView, WorkspaceId, WorkspaceView,
+  ApiProxy, HistoryEntry, HostFrame, ModelCatalogFailure, ModelProviderGroup, ModelReasoning,
+  MuxFrame, QuestionResponsePayload, SessionSearchItem, SessionSummary, ToolEventView,
+  WorkspaceId, WorkspaceView,
 } from './api/index.ts'
 import {
  SESSION_SEARCH_RESULT_LIMIT,
@@ -39,6 +45,7 @@ import type {
  AskUserQuestionAnswer, AskUserQuestionItem, AskUserQuestionRequest,
 } from '@deepseek-ai/dsh-user-interaction'
 import { UserInteractionError } from '@deepseek-ai/dsh-user-interaction'
+import { pickNativeDirectory } from './native-directory-picker.ts'

 /** Page size when history is called without maxMessages. */
 const DEFAULT_MAX_MESSAGES = 50
@@ -218,6 +225,8 @@ export interface ApiProxyDefaults {
  cwd: string
  /** Parent directory for name-created workspaces. */
  workspaceRoot: string
+  /** Native single-directory picker; injectable for carrier tests. */
+  pickDirectory?: (signal: AbortSignal) => Promise<string | null>
 }

 /** The tool/call payload fields the presenter path reads. */
@@ -381,6 +390,8 @@ function changedWorkspaceView(workspaceId: string, value: unknown): WorkspaceVie
 */
 export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiProxy {
  const agentOptions = { provider: defaults.provider, model: defaults.model }
+  type WebLlmTargetRef = AgentLlmTargetRef & { current: AgentLlmTarget }
+  const targets = new WeakMap<Agent, WebLlmTargetRef>()
  /** Implicit resume of cold sessions, deduplicating concurrent calls (follows the jsonrpc sessionCreations precedent). */
  const resumes = new Map<SessionId, Promise<Agent>>()
  /** Client-chosen identity creation/resume, deduplicated across concurrent retries. */
@@ -390,6 +401,40 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
  const pendingQuestions = new Map<RpcId, PendingQuestion>()
  const muxQueues = new Set<FrameQueue<RpcRequest<MuxFrame>>>()

+  /**
+   * Install or return the session-local target that prompt assembly snapshots.
+   * Seed order: latest logged request/header, else the host default routing.
+   * There is no create-time per-session override tier on this wire — if one
+   * returns (a create-options contribution), it must fold in between the two.
+   */
+  function targetFor(agent: Agent): WebLlmTargetRef {
+    const installed = targets.get(agent)
+    if (installed !== undefined) return installed
+    const logged = agent.session.requestHeader()?.config
+    const target: WebLlmTargetRef = {
+      current: logged === undefined
+        ? { provider: defaults.provider, model: defaults.model }
+        : {
+          provider: logged.provider,
+          model: logged.model,
+          ...logged.reasoningEffort === undefined
+            ? {}
+            : { reasoningEffort: logged.reasoningEffort },
+        },
+      assembled: undefined,
+    }
+    installAgentLlmTarget(agent.ctx, target)
+    targets.set(agent, target)
+    return target
+  }
+
+  /** Pre-publication setup used by both fresh and resumed Web agents. */
+  function installTarget(agentCtx: Context): void {
+    const agent = agentCtx.agent
+    if (agent === undefined) throw new Error('api-proxy: agent setup has no scoped agent')
+    targetFor(agent)
+  }
+
  /** Send one transient frame to every connected mux consumer. */
  function broadcast(payload: MuxFrame): void {
    const envelope = frame(payload)
@@ -403,7 +448,7 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
   * `agent/inbox/dequeue` OR `agent/inbox/discard` (the inbox contract), so
   * the mirror needs no consumption heuristics or sweeps beyond disposal.
   */
-  const queuedMirror = new Map<SessionId, Map<AgentMessageId, AgentMessage>>()
+  const queuedMirror = new Map<SessionId, Map<AgentMessageId, { message: AgentMessage; steering: boolean }>>()
  ctx.effect(() => {
    const retire = (agent: Agent, id: AgentMessageId): void => {
      const entries = queuedMirror.get(agent.id)
@@ -412,11 +457,21 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
      if (entries.size === 0) queuedMirror.delete(agent.id)
    }
    const disposers = [
-      ctx.on('agent/inbox/enqueue', (agent: Agent, message: AgentMessage) => {
+      ctx.on('agent/inbox/enqueue', (agent: Agent, message: AgentMessage, placement) => {
        let entries = queuedMirror.get(agent.id)
-        if (entries === undefined) queuedMirror.set(agent.id, entries = new Map<AgentMessageId, AgentMessage>())
-        entries.set(message.id, message)
-        broadcast({ type: 'session/queued', sessionId: agent.id, content: message.content, source: message.source, steering: message.steering })
+        if (entries === undefined) {
+          entries = new Map<AgentMessageId, { message: AgentMessage; steering: boolean }>()
+          queuedMirror.set(agent.id, entries)
+        }
+        const steering = placement === 'steering'
+        entries.set(message.id, { message, steering })
+        broadcast({
+          type: 'session/queued',
+          sessionId: agent.id,
+          content: message.content,
+          source: message.source,
+          steering,
+        })
      }),
      ctx.on('agent/inbox/dequeue', (agent: Agent, message: AgentMessage) => {
        retire(agent, message.id)
@@ -503,7 +558,11 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
      resume = (async () => {
        try {
          await assertServable(sessionId)
-          const handle = await ctx.agents.resume({ resumeSessionId: sessionId, agentOptions })
+          const handle = await ctx.agents.resume({
+            resumeSessionId: sessionId,
+            agentOptions,
+            setup: installTarget,
+          })
          return handle.agent
        } finally {
          resumes.delete(sessionId)
@@ -538,7 +597,11 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
          if (stored.cwd !== cwd) {
            throw new SessionCwdConflict(sessionId, cwd, stored.cwd)
          }
-          return (await ctx.agents.resume({ resumeSessionId: sessionId, agentOptions })).agent
+          return (await ctx.agents.resume({
+            resumeSessionId: sessionId,
+            agentOptions,
+            setup: installTarget,
+          })).agent
        }

        try {
@@ -546,7 +609,12 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
        } catch (error: unknown) {
          throw new Error(`failed to ensure project directory "${cwd}": ${String(error)}`, { cause: error })
        }
-        return (await ctx.agents.create({ sessionId, agentOptions, meta: { cwd } })).agent
+        return (await ctx.agents.create({
+          sessionId,
+          agentOptions,
+          meta: { cwd },
+          setup: installTarget,
+        })).agent
      })().catch((error: unknown) => {
        // Another Host entry path may have published the same identity while
        // this operation crossed an asynchronous persistence/filesystem step.
@@ -845,6 +913,107 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
        return ok(request, { events: entries, hasMore: page.hasMore, ...todos === undefined ? {} : { todos } })
      },

+      async models(request) {
+        const { sessionId } = request.payload
+        const found = await agentFor(sessionId)
+        if ('error' in found) return err(request, found.error)
+        const current = targetFor(found.agent).current
+        const catalog = await Promise.all(ctx.llm.listProviders().map(async (provider) => {
+          try {
+            const advertised = await ctx.llm.listModels(provider.id)
+            const models = [...advertised]
+            if (
+              provider.id === current.provider
+              && !models.some(model => model.id === current.model)
+            ) {
+              models.push({
+                provider: provider.id,
+                id: current.model,
+                name: current.model,
+              })
+            }
+            const entries = await Promise.all(models.map(async (model) => {
+              const resolved = await ctx.llm.resolveModelInfo(provider.id, model.id)
+              const reasoning: ModelReasoning | undefined = resolved.reasoning === undefined
+                ? undefined
+                : {
+                  efforts: resolved.reasoning.efforts.map(effort => ({
+                    id: effort.id,
+                    name: effort.name,
+                    ...effort.description === undefined
+                      ? {}
+                      : { description: effort.description },
+                  })),
+                  ...resolved.reasoning.defaultEffort === undefined
+                    ? {}
+                    : { defaultEffort: resolved.reasoning.defaultEffort },
+                }
+              return {
+                id: model.id,
+                name: model.name,
+                ...model.description === undefined ? {} : { description: model.description },
+                ...provider.id === current.provider
+                  && model.id === current.model
+                  && !advertised.some(candidate => candidate.id === current.model)
+                  ? { unlisted: true as const }
+                  : {},
+                ...reasoning === undefined ? {} : { reasoning },
+              }
+            }))
+            const group: ModelProviderGroup = {
+              id: provider.id,
+              name: provider.name,
+              models: entries,
+            }
+            return { kind: 'group' as const, group }
+          } catch (error: unknown) {
+            const failure: ModelCatalogFailure = {
+              id: provider.id,
+              name: provider.name,
+              message: error instanceof Error ? error.message : String(error),
+            }
+            return { kind: 'failure' as const, failure }
+          }
+        }))
+        const groups = catalog.flatMap(item => item.kind === 'group' ? [item.group] : [])
+        const failures = catalog.flatMap(item => item.kind === 'failure' ? [item.failure] : [])
+        return ok(request, {
+          current: { ...current },
+          groups: groups.filter(group => group.models.length > 0),
+          failures,
+        })
+      },
+
+      async selectModel(request) {
+        const { sessionId, provider, model, reasoningEffort } = request.payload
+        const found = await agentFor(sessionId)
+        if ('error' in found) return err(request, found.error)
+        try {
+          const resolved = await ctx.llm.resolveCallConfig({
+            provider,
+            model,
+            ...reasoningEffort === undefined
+              ? {}
+              : { reasoningEffort: ReasoningEffortId(reasoningEffort) },
+          })
+          const selected: AgentLlmTarget = {
+            provider: resolved.provider,
+            model: resolved.model,
+            ...resolved.reasoningEffort === undefined
+              ? {}
+              : { reasoningEffort: resolved.reasoningEffort },
+          }
+          targetFor(found.agent).current = selected
+          return ok(request, { selected: { ...selected } })
+        } catch (error: unknown) {
+          return err(request, {
+            code: 'model-unavailable',
+            message: error instanceof Error ? error.message : String(error),
+            details: { provider, model },
+          })
+        }
+      },
+
      async prompt(request) {
        const { sessionId, mode, content } = request.payload
        const found = await agentFor(sessionId)
@@ -853,8 +1022,8 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
        // The rpcId rides MessageSource into user/message (merge declaration in api/sessions.ts; provisional correlation).
        const source: MessageSource = { kind: 'user', rpcId: request.rpcId }
        try {
-          if (mode === 'steer') agent.steer(content, { source })
-          else agent.followup(content, { source })
+          if (mode === 'steer') agent.steer({ content, source })
+          else agent.followup({ content, source })
        } catch (error: unknown) {
          // A synchronous throw from steer/followup means disposed or invalid input; surface as agent-busy with the reason attached.
          return err(request, { code: 'agent-busy', message: 'prompt rejected', details: { reason: String(error) } })
@@ -872,7 +1041,7 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
            details: { sessionId },
          }))
        }
-        agent.cancel()
+        agent.cancel({ kind: 'user' })
        return Promise.resolve(ok(request, { accepted: true as const }))
      },
    },
@@ -1010,6 +1179,26 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
          attachedSessions: ctx.agents.list().length,
        }))
      },
+
+      async pickDirectory(request, signal) {
+        try {
+          const path = await (defaults.pickDirectory ?? pickNativeDirectory)(signal)
+          return ok(request, { path })
+        } catch (error: unknown) {
+          if (signal.aborted) {
+            return err(request, {
+              code: 'cancelled',
+              message: 'directory picker was aborted',
+              details: {},
+            })
+          }
+          return err(request, {
+            code: 'internal',
+            message: `directory picker failed: ${error instanceof Error ? error.message : String(error)}`,
+            details: {},
+          })
+        }
+      },
    },

    commands: {
@@ -1115,7 +1304,13 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
        // queue view from these alone.
        for (const [sessionId, entries] of queuedMirror) {
          for (const entry of entries.values()) {
-            queue.push(frame({ type: 'session/queued', sessionId, content: entry.content, source: entry.source, steering: entry.steering }))
+            queue.push(frame({
+              type: 'session/queued',
+              sessionId,
+              content: entry.message.content,
+              source: entry.message.source,
+              steering: entry.steering,
+            }))
          }
        }
        // Per-session open-call table for result-view pairing. Bounded by the
@@ -1179,11 +1374,10 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
            queue.push(frame({ type: 'host/session-removed', sessionId: session.id }))
          }),
          ctx.on('agent/status', (agent: Agent, status: AgentStatus) => {
-            if (status === 'disposed') return
            queue.push(frame({ type: 'host/session-status', sessionId: agent.id, running: status === 'running' }))
          }),
-          ctx.on('agent/error', (agent: Agent, _turn: number, _step: number, error: Error) => {
-            queue.push(frame({ type: 'host/agent-error', sessionId: agent.id, message: String(error) }))
+          ctx.on('agent/error', (agent: Agent, _turn: number, _step: number, error: unknown) => {
+            queue.push(frame({ type: 'host/agent-error', sessionId: agent.id, message: errorChain(error) }))
          }),
          ctx.on('domain/changed', (change) => {
            if (change.domain !== 'workspace') return
--- a/packages/host/apiproxy/src/api/events.ts
+++ b/packages/host/apiproxy/src/api/events.ts
@@ -63,14 +63,16 @@ export type MuxFrame =
  | { type: 'question/requested'; sessionId: SessionId; questions: AskUserQuestionItem[] }
  | { type: 'question/resolved'; sessionId: SessionId; questionRpcId: RpcId; outcome: 'answered' | 'cancelled' }
  /**
-   * A message entered the addressed agent's inbox (`agent/queued` passthrough:
-   * a queued message is not model-visible, so there is no session event to
-   * ride — this transient frame is the only wire signal). On stream open the
+   * A message entered the addressed agent's inbox. A queued message is not
+   * model-visible, so there is no session event to carry it; this transient
+   * frame is the only wire signal. On stream open the
   * host replays the current queue snapshot for every attached session (same
   * refresh-recovery baseline as pending questions); queue clearing on cancel
   * has no dedicated frame — clients fold it from the status flip.
-   * source carries the prompt's rpcId when the message came over this wire
-   * (the client's provisional-echo reconciliation key).
+   * `steering` is the host's acceptance-time queue classification and remains
+   * authoritative in reconnect snapshots. `source` carries the prompt's rpcId
+   * when the message came over this wire (the client's provisional-echo
+   * reconciliation key).
   */
  | { type: 'session/queued'; sessionId: SessionId; content: ContentBlock[]; source: MessageSource; steering: boolean }
  | { type: 'stream/error'; error: RpcError }
--- a/packages/host/apiproxy/src/api/host.schema.ts
+++ b/packages/host/apiproxy/src/api/host.schema.ts
@@ -17,3 +17,11 @@ export const hostDescribeValueSchema = z.object({
  model: z.string().optional(),
  attachedSessions: z.number().int().nonnegative(),
 }) satisfies z.ZodType<Wire<ResponseValue<'host.describe'>>>
+
+/** host.pickDirectory request payload (empty object literal). */
+export const hostPickDirectoryRequestSchema = z.object({}) satisfies z.ZodType<Wire<RequestPayload<'host.pickDirectory'>>>
+
+/** host.pickDirectory response value; null means the user cancelled. */
+export const hostPickDirectoryValueSchema = z.object({
+  path: z.string().nullable(),
+}) satisfies z.ZodType<Wire<ResponseValue<'host.pickDirectory'>>>
--- a/packages/host/apiproxy/src/api/host.ts
+++ b/packages/host/apiproxy/src/api/host.ts
@@ -22,4 +22,10 @@ export interface HostApi {
    model?: string
    attachedSessions: number
  }>>
+
+  /** Open the operating system's single-directory picker; cancellation returns null. */
+  pickDirectory(
+    request: RpcRequest<{}>,
+    signal: AbortSignal,
+  ): Promise<RpcResponse<{ path: string | null }>>
 }
--- a/packages/host/apiproxy/src/api/index.ts
+++ b/packages/host/apiproxy/src/api/index.ts
@@ -25,7 +25,10 @@ export interface ApiProxy {
 }

 // ---- Domain interfaces and payload entities ----
-export type { HistoryEntry, SessionSearchItem, SessionsApi, SessionSummary } from './sessions.ts'
+export type {
+  HistoryEntry, ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
+  ModelReasoningEffort, ModelTarget, SessionModels, SessionSearchItem, SessionsApi, SessionSummary,
+} from './sessions.ts'
 export type { HostApi } from './host.ts'
 export type { WorkspaceApi, WorkspaceId, WorkspaceView } from './workspace.ts'
 export type { CommandsApi, CommandDescriptor, CommandExecuteResult } from './commands.ts'
--- a/packages/host/apiproxy/src/api/rpc-map.ts
+++ b/packages/host/apiproxy/src/api/rpc-map.ts
@@ -21,9 +21,12 @@ export interface RpcMethodMap {
  'session.search': SessionsApi['search']
  'session.create': SessionsApi['create']
  'session.history': SessionsApi['history']
+  'session.models': SessionsApi['models']
+  'session.selectModel': SessionsApi['selectModel']
  'session.prompt': SessionsApi['prompt']
  'session.cancel': SessionsApi['cancel']
  'host.describe': HostApi['describe']
+  'host.pickDirectory': HostApi['pickDirectory']
  'workspace.list': WorkspaceApi['list']
  'workspace.create': WorkspaceApi['create']
  'workspace.rename': WorkspaceApi['rename']
--- a/packages/host/apiproxy/src/api/rpc.schema.ts
+++ b/packages/host/apiproxy/src/api/rpc.schema.ts
@@ -35,6 +35,7 @@ export const rpcErrorSchema: z.ZodType<RpcError> = z.discriminatedUnion('code',
  z.object({ code: z.literal('bad-request'), message: z.string(), details: z.object({ issues: z.array(z.custom<ZodIssue>()) }) }),
  z.object({ code: z.literal('cancelled'), message: z.string(), details: z.object({}) }),
  z.object({ code: z.literal('session-not-found'), message: z.string(), details: z.object({ sessionId: z.string() }) }),
+  z.object({ code: z.literal('model-unavailable'), message: z.string(), details: z.object({ provider: z.string(), model: z.string() }) }),
  z.object({ code: z.literal('session-conflict'), message: z.string(), details: z.object({ sessionId: z.string(), requestedCwd: z.string(), existingCwd: z.string().optional() }) }),
  z.object({ code: z.literal('workspace-attach-failed'), message: z.string(), details: z.object({ sessionId: z.string(), workspaceId: z.string() }) }),
  z.object({ code: z.literal('workspace-not-found'), message: z.string(), details: z.object({ workspaceId: z.string() }) }),
--- a/packages/host/apiproxy/src/api/rpc.ts
+++ b/packages/host/apiproxy/src/api/rpc.ts
@@ -32,6 +32,7 @@ export interface RpcErrorDetailsMap {
  'bad-request': { issues: ZodIssue[] }
  'cancelled': {}
  'session-not-found': { sessionId: SessionId }
+  'model-unavailable': { provider: string; model: string }
  'session-conflict': { sessionId: SessionId; requestedCwd: string; existingCwd?: string }
  'workspace-attach-failed': { sessionId: SessionId; workspaceId: string }
  'workspace-not-found': { workspaceId: string }
--- a/packages/host/apiproxy/src/api/sessions.schema.ts
+++ b/packages/host/apiproxy/src/api/sessions.schema.ts
@@ -9,7 +9,10 @@ import { z } from 'zod'
 import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session/types'
 import type { RequestPayload, ResponseValue } from './rpc-map.ts'
 import type { Wire } from './rpc.schema.ts'
-import type { HistoryEntry, SessionSearchItem, SessionSummary } from './sessions.ts'
+import type {
+  HistoryEntry, ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
+  ModelReasoningEffort, ModelTarget, SessionSearchItem, SessionSummary,
+} from './sessions.ts'
 import type { ToolEventView } from './events.ts'
 import type { WorkspaceId } from './workspace.ts'
 import {
@@ -108,6 +111,49 @@ export const sessionHistoryRequestSchema = z.object({
  maxMessages: z.number().int().positive().optional(),
 }) satisfies z.ZodType<Wire<RequestPayload<'session.history'>>>

+/** Complete provider/model target. */
+export const modelTargetSchema = z.object({
+  provider: z.string().min(1),
+  model: z.string().min(1),
+  reasoningEffort: z.string().min(1).optional(),
+}) satisfies z.ZodType<Wire<ModelTarget>>
+
+/** One adapter-owned reasoning effort. */
+export const modelReasoningEffortSchema = z.object({
+  id: z.string().min(1),
+  name: z.string().min(1),
+  description: z.string().optional(),
+}) satisfies z.ZodType<Wire<ModelReasoningEffort>>
+
+/** Exact-model reasoning metadata. */
+export const modelReasoningSchema = z.object({
+  efforts: z.array(modelReasoningEffortSchema).min(1),
+  defaultEffort: z.string().min(1).optional(),
+}) satisfies z.ZodType<Wire<ModelReasoning>>
+
+/** One advisory model entry inside a provider group. */
+export const modelCatalogModelSchema = z.object({
+  id: z.string().min(1),
+  name: z.string().min(1),
+  description: z.string().optional(),
+  unlisted: z.literal(true).optional(),
+  reasoning: modelReasoningSchema.optional(),
+}) satisfies z.ZodType<Wire<ModelCatalogModel>>
+
+/** One successfully loaded provider group. */
+export const modelProviderGroupSchema = z.object({
+  id: z.string().min(1),
+  name: z.string().min(1),
+  models: z.array(modelCatalogModelSchema),
+}) satisfies z.ZodType<Wire<ModelProviderGroup>>
+
+/** One provider-local catalog failure. */
+export const modelCatalogFailureSchema = z.object({
+  id: z.string().min(1),
+  name: z.string().min(1),
+  message: z.string(),
+}) satisfies z.ZodType<Wire<ModelCatalogFailure>>
+
 /**
 * ToolEventView passthrough: lock only the `for` discriminant and the presence
 * of a card-tagged `view` object. The view interior is a host-computed product
@@ -138,6 +184,31 @@ export const sessionHistoryValueSchema = z.object({
  todos: z.array(todoItemSchema).optional(),
 }) satisfies z.ZodType<Wire<ResponseValue<'session.history'>>>

+/** session.models request payload. */
+export const sessionModelsRequestSchema = z.object({
+  sessionId: sessionIdSchema,
+}) satisfies z.ZodType<Wire<RequestPayload<'session.models'>>>
+
+/** session.models response value. */
+export const sessionModelsValueSchema = z.object({
+  current: modelTargetSchema,
+  groups: z.array(modelProviderGroupSchema),
+  failures: z.array(modelCatalogFailureSchema),
+}) satisfies z.ZodType<Wire<ResponseValue<'session.models'>>>
+
+/** session.selectModel request payload. */
+export const sessionSelectModelRequestSchema = z.object({
+  sessionId: sessionIdSchema,
+  provider: z.string().min(1),
+  model: z.string().min(1),
+  reasoningEffort: z.string().min(1).optional(),
+}) satisfies z.ZodType<Wire<RequestPayload<'session.selectModel'>>>
+
+/** session.selectModel response value. */
+export const sessionSelectModelValueSchema = z.object({
+  selected: modelTargetSchema,
+}) satisfies z.ZodType<Wire<ResponseValue<'session.selectModel'>>>
+
 /** ContentBlock passthrough: core is merge-extensible — the type discriminant envelope is strict, the rest stays wide. */
 export const contentBlockSchema = z.looseObject({ type: z.string() })

--- a/packages/host/apiproxy/src/api/sessions.ts
+++ b/packages/host/apiproxy/src/api/sessions.ts
@@ -32,6 +32,78 @@ export interface HistoryEntry {
  view?: ToolEventView
 }

+/** Complete model target selected for one session. */
+export interface ModelTarget {
+  /** Registered provider route. */
+  provider: string
+  /** Provider-owned model id. */
+  model: string
+  /** Adapter-owned reasoning effort; absence preserves adapter/provider default behavior. */
+  reasoningEffort?: string
+}
+
+/** One adapter-owned reasoning effort displayed for an exact model route. */
+export interface ModelReasoningEffort {
+  /** Opaque value submitted back to the owning adapter. */
+  id: string
+  /** Adapter-supplied display name. */
+  name: string
+  /** Optional adapter-supplied description. */
+  description?: string
+}
+
+/** Selectable reasoning metadata for one exact model route. */
+export interface ModelReasoning {
+  /** Efforts in adapter-preferred display order. */
+  efforts: ModelReasoningEffort[]
+  /** Adapter-configured default; absence preserves the provider default. */
+  defaultEffort?: string
+}
+
+/** One model displayed inside its provider group. */
+export interface ModelCatalogModel {
+  /** Provider-owned model id. */
+  id: string
+  /** Provider-supplied display name. */
+  name: string
+  /** Optional provider-supplied description. */
+  description?: string
+  /** The current model was inserted because the advisory catalog omitted it. */
+  unlisted?: true
+  /** Exact-route reasoning metadata when the adapter exposes it. */
+  reasoning?: ModelReasoning
+}
+
+/** One provider and the models it advertised successfully. */
+export interface ModelProviderGroup {
+  /** Provider route id used for requests. */
+  id: string
+  /** Provider display name. */
+  name: string
+  /** Models in provider-preferred order. */
+  models: ModelCatalogModel[]
+}
+
+/** A provider whose asynchronous catalog lookup failed. */
+export interface ModelCatalogFailure {
+  /** Provider route id. */
+  id: string
+  /** Provider display name. */
+  name: string
+  /** Lookup failure diagnostic. */
+  message: string
+}
+
+/** Detached model-directory snapshot for one session. */
+export interface SessionModels {
+  /** Target selected for the session's next assembled step. */
+  current: ModelTarget
+  /** Successfully loaded provider groups. */
+  groups: ModelProviderGroup[]
+  /** Provider-local failures; successful groups remain usable. */
+  failures: ModelCatalogFailure[]
+}
+
 /** Session list entry (v1 builds no index: list does readdir+stat). */
 export interface SessionSummary {
  sessionId: SessionId
@@ -102,6 +174,22 @@ export interface SessionsApi {
  history(request: RpcRequest<{ sessionId: SessionId; beforeSeq?: number; maxMessages?: number }>):
  Promise<RpcResponse<{ events: HistoryEntry[]; hasMore: boolean; todos?: TodoItem[] }>>

+  /** Reads a fresh advisory model directory for this session. Provider lookups run independently. */
+  models(request: RpcRequest<{ sessionId: SessionId }>): Promise<RpcResponse<SessionModels>>
+
+  /**
+   * Selects the complete target for this session. Exact model metadata
+   * validates an optional reasoning effort, while catalog membership remains
+   * advisory.
+   */
+  selectModel(request: RpcRequest<{
+    sessionId: SessionId
+    provider: string
+    model: string
+    reasoningEffort?: string
+  }>):
+  Promise<RpcResponse<{ selected: ModelTarget }>>
+
  /** Sends a message. content is core's ContentBlock[] verbatim; mode maps 1:1 — queue→send, steer→steer. */
  prompt(request: RpcRequest<{ sessionId: SessionId; mode: 'queue' | 'steer'; content: ContentBlock[] }>):
  Promise<RpcResponse<{ accepted: true }>>
--- a/packages/host/apiproxy/src/fetch/client.ts
+++ b/packages/host/apiproxy/src/fetch/client.ts
@@ -13,14 +13,16 @@ import { RpcId } from '../api/rpc.ts'
 import type { Wire } from '../api/rpc.schema.ts'
 import { rpcReceiptSchema, serverRequestSchema, serverResponseSchema } from '../api/rpc.schema.ts'
 import { hostFrameSchema, muxFrameSchema } from '../api/events.schema.ts'
-import { hostDescribeValueSchema } from '../api/host.schema.ts'
+import { hostDescribeValueSchema, hostPickDirectoryValueSchema } from '../api/host.schema.ts'
 import {
  sessionCancelValueSchema,
  sessionCreateValueSchema,
  sessionHistoryValueSchema,
  sessionListValueSchema,
+  sessionModelsValueSchema,
  sessionPromptValueSchema,
  sessionSearchValueSchema,
+  sessionSelectModelValueSchema,
 } from '../api/sessions.schema.ts'
 import {
  workspaceCreateValueSchema,
@@ -53,11 +55,14 @@ export interface IApiClient {
    search(payload: RequestPayload<'session.search'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'session.search'>>>
    create(payload: RequestPayload<'session.create'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'session.create'>>>
    history(payload: RequestPayload<'session.history'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'session.history'>>>
+    models(payload: RequestPayload<'session.models'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'session.models'>>>
+    selectModel(payload: RequestPayload<'session.selectModel'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'session.selectModel'>>>
    prompt(payload: RequestPayload<'session.prompt'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'session.prompt'>>>
    cancel(payload: RequestPayload<'session.cancel'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'session.cancel'>>>
  }
  host: {
    describe(payload: RequestPayload<'host.describe'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'host.describe'>>>
+    pickDirectory(payload: RequestPayload<'host.pickDirectory'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'host.pickDirectory'>>>
  }
  workspace: {
    list(payload: RequestPayload<'workspace.list'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'workspace.list'>>>
@@ -90,9 +95,12 @@ const UNARY_VALUE_SCHEMAS: { [K in keyof RpcMethodMap]: z.ZodType<Wire<ResponseV
  'session.search': sessionSearchValueSchema,
  'session.create': sessionCreateValueSchema,
  'session.history': sessionHistoryValueSchema,
+  'session.models': sessionModelsValueSchema,
+  'session.selectModel': sessionSelectModelValueSchema,
  'session.prompt': sessionPromptValueSchema,
  'session.cancel': sessionCancelValueSchema,
  'host.describe': hostDescribeValueSchema,
+  'host.pickDirectory': hostPickDirectoryValueSchema,
  'workspace.list': workspaceListValueSchema,
  'workspace.create': workspaceCreateValueSchema,
  'workspace.rename': workspaceRenameValueSchema,
@@ -180,13 +188,22 @@ export abstract class AbstractApiClient implements IApiClient {
   * Shared POST leg of both C→S carriers (callUnary/respond): JSON body,
   * timeout merged with the caller's optional external signal, non-2xx → transport throw.
   */
-  private async postJson(path: string, body: ClientRequest | ClientResponse, signal: AbortSignal | undefined): Promise<Response> {
-    const timeout = AbortSignal.timeout(this.timeoutMs)
+  private async postJson(
+    path: string,
+    body: ClientRequest | ClientResponse,
+    signal: AbortSignal | undefined,
+    useDefaultTimeout = true,
+  ): Promise<Response> {
+    const requestSignal = useDefaultTimeout
+      ? signal === undefined
+        ? AbortSignal.timeout(this.timeoutMs)
+        : AbortSignal.any([AbortSignal.timeout(this.timeoutMs), signal])
+      : signal
    const response = await this.doFetch(new URL(path, this.resolveBase()), {
      method: 'POST',
      headers: { 'content-type': 'application/json' },
      body: JSON.stringify(body),
-      signal: signal === undefined ? timeout : AbortSignal.any([timeout, signal]),
+      ...requestSignal === undefined ? {} : { signal: requestSignal },
    })
    if (!response.ok) throw new Error(`transport failure for ${path}: HTTP ${response.status}`)
    return response
@@ -201,10 +218,11 @@ export abstract class AbstractApiClient implements IApiClient {
    method: K,
    payload: RequestPayload<K>,
    signal?: AbortSignal,
+    useDefaultTimeout = true,
  ): Promise<RpcResponse<ResponseValue<K>>> {
    const message: ClientRequest = { type: 'client-request', rpcId: this.mintRpcId(), method, payload }
    this.onEnvelope(message)
-    const response = await this.postJson(`/api/${method}`, message, signal)
+    const response = await this.postJson(`/api/${method}`, message, signal, useDefaultTimeout)
    const full = serverResponseSchema.parse(await response.json())
    this.onEnvelope(full)
    if (full.rpcId !== message.rpcId) throw new Error(`rpcId mismatch for ${method}: sent ${message.rpcId}, got ${full.rpcId}`)
@@ -280,12 +298,17 @@ export abstract class AbstractApiClient implements IApiClient {
    search: (payload, signal) => this.callUnary('session.search', payload, signal),
    create: (payload, signal) => this.callUnary('session.create', payload, signal),
    history: (payload, signal) => this.callUnary('session.history', payload, signal),
+    models: (payload, signal) => this.callUnary('session.models', payload, signal),
+    selectModel: (payload, signal) => this.callUnary('session.selectModel', payload, signal),
    prompt: (payload, signal) => this.callUnary('session.prompt', payload, signal),
    cancel: (payload, signal) => this.callUnary('session.cancel', payload, signal),
  }

  readonly host: IApiClient['host'] = {
    describe: (payload, signal) => this.callUnary('host.describe', payload, signal),
+    // A native system dialog is user-paced and may legitimately stay open
+    // longer than the normal unary deadline. Caller/connection aborts remain.
+    pickDirectory: (payload, signal) => this.callUnary('host.pickDirectory', payload, signal, false),
  }

  readonly workspace: IApiClient['workspace'] = {
--- a/packages/host/apiproxy/src/fetch/handler.ts
+++ b/packages/host/apiproxy/src/fetch/handler.ts
@@ -19,10 +19,12 @@ import {
  sessionCreateRequestSchema,
  sessionHistoryRequestSchema,
  sessionListRequestSchema,
+  sessionModelsRequestSchema,
  sessionPromptRequestSchema,
  sessionSearchRequestSchema,
+  sessionSelectModelRequestSchema,
 } from '../api/sessions.schema.ts'
-import { hostDescribeRequestSchema } from '../api/host.schema.ts'
+import { hostDescribeRequestSchema, hostPickDirectoryRequestSchema } from '../api/host.schema.ts'
 import {
  workspaceCreateRequestSchema,
  workspaceDeleteRequestSchema,
@@ -55,9 +57,12 @@ const UNARY_ROUTES: UnaryRoutes = {
  'session.search': { schema: sessionSearchRequestSchema, invoke: (api, r, signal) => api.sessions.search(r, signal) },
  'session.create': { schema: sessionCreateRequestSchema, invoke: (api, r) => api.sessions.create(r) },
  'session.history': { schema: sessionHistoryRequestSchema, invoke: (api, r) => api.sessions.history(r) },
+  'session.models': { schema: sessionModelsRequestSchema, invoke: (api, r) => api.sessions.models(r) },
+  'session.selectModel': { schema: sessionSelectModelRequestSchema, invoke: (api, r) => api.sessions.selectModel(r) },
  'session.prompt': { schema: sessionPromptRequestSchema, invoke: (api, r) => api.sessions.prompt(r) },
  'session.cancel': { schema: sessionCancelRequestSchema, invoke: (api, r) => api.sessions.cancel(r) },
  'host.describe': { schema: hostDescribeRequestSchema, invoke: (api, r) => api.host.describe(r) },
+  'host.pickDirectory': { schema: hostPickDirectoryRequestSchema, invoke: (api, r, signal) => api.host.pickDirectory(r, signal) },
  'workspace.list': { schema: workspaceListRequestSchema, invoke: (api, r) => api.workspace.list(r) },
  'workspace.create': { schema: workspaceCreateRequestSchema, invoke: (api, r) => api.workspace.create(r) },
  'workspace.rename': { schema: workspaceRenameRequestSchema, invoke: (api, r) => api.workspace.rename(r) },
--- a/packages/host/apiproxy/src/index.ts
+++ b/packages/host/apiproxy/src/index.ts
@@ -45,7 +45,7 @@ export interface Config {
 * project directory and the fallback parent for name-created Workspaces.
 */
 export class ApiProxyService extends Service implements ApiProxy {
-  static inject = ['agents', 'sessions', 'tools', 'userInteraction', 'workspace']
+  static inject = ['agents', 'llm', 'sessions', 'tools', 'userInteraction', 'workspace']

  static Config: z<Config> = z.object({
    provider: z.string().required(),
--- a/packages/host/apiproxy/src/native-directory-picker.ts
+++ b/packages/host/apiproxy/src/native-directory-picker.ts
@@ -0,0 +1,136 @@
+/** Cross-platform native single-directory picker used by the local GUI carrier. */
+
+import { execFile } from 'node:child_process'
+
+/** Testable command boundary; native implementations never invoke a shell. */
+export type DirectoryPickerRunner = (
+  command: string,
+  args: readonly string[],
+  signal: AbortSignal,
+) => Promise<{ stdout: string; stderr: string }>
+
+/** Injectable platform facts for deterministic adapter tests. */
+export interface DirectoryPickerInternals {
+  platform?: NodeJS.Platform
+  run?: DirectoryPickerRunner
+}
+
+const runCommand: DirectoryPickerRunner = (command, args, signal) =>
+  new Promise((resolve, reject) => {
+    execFile(
+      command,
+      [...args],
+      { encoding: 'utf8', signal, windowsHide: true },
+      (error, stdout, stderr) => {
+        if (error !== null) {
+          const failure = Object.assign(new Error(error.message, { cause: error }), {
+            code: error.code,
+            stdout,
+            stderr,
+          })
+          reject(failure)
+          return
+        }
+        resolve({ stdout, stderr })
+      },
+    )
+  })
+
+function outputPath(stdout: string): string | null {
+  const path = stdout.replace(/[\r\n]+$/, '')
+  return path === '' ? null : path
+}
+
+function errorCode(error: unknown): string | number | undefined {
+  if (typeof error !== 'object' || error === null || !('code' in error)) return undefined
+  const code = (error as { code?: unknown }).code
+  return typeof code === 'string' || typeof code === 'number' ? code : undefined
+}
+
+function errorStderr(error: unknown): string {
+  if (typeof error !== 'object' || error === null || !('stderr' in error)) return ''
+  const stderr = (error as { stderr?: unknown }).stderr
+  return typeof stderr === 'string' ? stderr : ''
+}
+
+function isMissingCommand(error: unknown): boolean {
+  return errorCode(error) === 'ENOENT'
+}
+
+function rethrowIfAborted(signal: AbortSignal, error: unknown): void {
+  if (signal.aborted) throw error
+}
+
+/**
+ * Open the platform directory picker.
+ * @param signal - caller/connection lifetime; abort terminates the native command.
+ * @param internals - platform and runner seam for deterministic tests.
+ * @returns the selected path, or null when the user cancels.
+ */
+export async function pickNativeDirectory(
+  signal: AbortSignal,
+  internals: DirectoryPickerInternals = {},
+): Promise<string | null> {
+  const platform = internals.platform ?? process.platform
+  const run = internals.run ?? runCommand
+
+  if (platform === 'darwin') {
+    try {
+      const result = await run('osascript', [
+        '-e', 'set selectedFolder to choose folder with prompt "Select Workspace Directory"',
+        '-e', 'POSIX path of selectedFolder',
+      ], signal)
+      return outputPath(result.stdout)
+    } catch (error: unknown) {
+      if (!signal.aborted && errorCode(error) === 1
+        && /(?:User canceled|-128)/i.test(errorStderr(error))) return null
+      throw error
+    }
+  }
+
+  if (platform === 'win32') {
+    const script = [
+      "$ErrorActionPreference = 'Stop'",
+      'Add-Type -AssemblyName System.Windows.Forms',
+      '$dialog = New-Object System.Windows.Forms.FolderBrowserDialog',
+      "$dialog.Description = 'Select Workspace Directory'",
+      '$dialog.ShowNewFolderButton = $true',
+      '$result = $dialog.ShowDialog()',
+      'if ($result -eq [System.Windows.Forms.DialogResult]::OK) {',
+      '  [Console]::OutputEncoding = [System.Text.Encoding]::UTF8',
+      '  [Console]::WriteLine($dialog.SelectedPath)',
+      '}',
+    ].join('; ')
+    const result = await run('powershell.exe', ['-NoProfile', '-STA', '-Command', script], signal)
+    return outputPath(result.stdout)
+  }
+
+  if (platform === 'linux') {
+    try {
+      const result = await run('zenity', [
+        '--file-selection', '--directory', '--title=Select Workspace Directory',
+      ], signal)
+      return outputPath(result.stdout)
+    } catch (error: unknown) {
+      rethrowIfAborted(signal, error)
+      if (errorCode(error) === 1) return null
+      if (!isMissingCommand(error)) throw error
+    }
+
+    try {
+      const result = await run('kdialog', [
+        '--getexistingdirectory', '.', '--title', 'Select Workspace Directory',
+      ], signal)
+      return outputPath(result.stdout)
+    } catch (error: unknown) {
+      rethrowIfAborted(signal, error)
+      if (errorCode(error) === 1) return null
+      if (isMissingCommand(error)) {
+        throw new Error('no supported native directory picker found (install zenity or kdialog)')
+      }
+      throw error
+    }
+  }
+
+  throw new Error(`native directory picker is unsupported on ${platform}`)
+}
--- a/packages/host/apiproxy/tests/api-proxy-cold.spec.ts
+++ b/packages/host/apiproxy/tests/api-proxy-cold.spec.ts
@@ -1,8 +1,9 @@
 /**
 * Cold-session and degenerate-composition paths of the host ApiProxy:
 * sessions.list merging persisted-but-unattached summaries (mtime source,
- * createdAt fallbacks, lineage projection) and the resume error split when
- * the composition has no persistence gate and no agent factory.
+ * createdAt fallbacks, lineage projection), the resume error split when
+ * the composition has no persistence gate and no agent factory, and the
+ * agent-busy mapping of a synchronous prompt rejection.
 */

 import { mkdtempSync, writeFileSync, utimesSync } from 'node:fs'
@@ -12,6 +13,7 @@ import { describe, expect, it } from 'vitest'
 import { Context } from 'cordis'
 import SessionStore from '@deepseek-ai/dsh-session'
 import AgentRegistry from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
 import UserInteractionService from '@deepseek-ai/dsh-user-interaction'
 import type { SessionHeader, SessionId } from '@deepseek-ai/dsh-session'
 import type { RpcRequest } from '@deepseek-ai/dsh-host-apiproxy/api/rpc'
@@ -98,3 +100,38 @@ describe('degenerate composition (no persistence, no factory)', () => {
    }
  })
 })
+
+describe('sessions.prompt synchronous rejection', () => {
+  it('maps a synchronous send throw (disposed/invalid input) to agent-busy with the reason attached', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SessionStore)
+    await ctx.plugin(AgentRegistry)
+    await ctx.plugin(UserInteractionService)
+    const session = ctx.sessions.create(sid('session-throwing'))
+    // A live structural stub whose delivery verbs throw synchronously, the
+    // shape a disposed loop presents at this seam.
+    ctx.agents.register({
+      id: session.id,
+      session,
+      status: 'idle',
+      ctx,
+      followup: () => { throw new Error('agent "session-throwing" lifecycle disposed') },
+      steer: () => { throw new Error('agent "session-throwing" lifecycle disposed') },
+    } as unknown as Agent)
+    const api = createApiProxy(ctx, { provider: 'p', model: 'm', cwd: '/tmp', workspaceRoot: '/tmp' })
+
+    for (const mode of ['queue', 'steer'] as const) {
+      const response = await api.sessions.prompt(request({
+        sessionId: session.id, mode, content: [{ type: 'text' as const, text: 'x' }],
+      }))
+      expect(response.result.ok).toBe(false)
+      if (!response.result.ok) {
+        expect(response.result.error.code).toBe('agent-busy')
+        expect(response.result.error.message).toBe('prompt rejected')
+        expect(response.result.error.details).toEqual({
+          reason: 'Error: agent "session-throwing" lifecycle disposed',
+        })
+      }
+    }
+  })
+})
--- a/packages/host/apiproxy/tests/api-proxy-commands.spec.ts
+++ b/packages/host/apiproxy/tests/api-proxy-commands.spec.ts
@@ -238,14 +238,11 @@ describe('host/commands-changed frame', () => {
 })

 /** Build one frozen inbox message for the live `agent/inbox/*` events. */
-function inboxMessage(id: string, text: string, steering: boolean, rpcId?: string): AgentMessage {
+function inboxMessage(id: string, text: string, rpcId?: string): AgentMessage {
  return Object.freeze({
    id: AgentMessageId(id),
    content: [{ type: 'text' as const, text }],
    source: rpcId === undefined ? { kind: 'user' as const } : { kind: 'user' as const, rpcId: RpcId(rpcId) },
-    contexts: [],
-    steering,
-    wakeup: true,
  })
 }

@@ -259,10 +256,10 @@ describe('session/queued frames', () => {
    // subscribed baseline + 2 queued frames
    const liveCollected = collect<MuxFrame>(liveStream, 3, live)

-    const queued = inboxMessage('m-1', 'queued prompt', false)
-    const steering = inboxMessage('m-2', 'queued prompt', true)
-    ctx.emit('agent/inbox/enqueue', agent, queued)
-    ctx.emit('agent/inbox/enqueue', agent, steering)
+    const queued = inboxMessage('m-1', 'queued prompt')
+    const steering = inboxMessage('m-2', 'queued prompt')
+    ctx.emit('agent/inbox/enqueue', agent, queued, 'queued')
+    ctx.emit('agent/inbox/enqueue', agent, steering, 'steering')

    const liveFrames = (await liveCollected).filter(f => f.type === 'session/queued')
    expect(liveFrames).toEqual([
@@ -274,17 +271,17 @@ describe('session/queued frames', () => {
    const replay = new AbortController()
    const replayFrames = await collect<MuxFrame>(
      api.events.mux({ rpcId: RpcId('t-mux-replay'), payload: {} }, replay.signal), 3, replay)
-    expect(replayFrames.filter(f => f.type === 'session/queued')).toHaveLength(2)
+    expect(replayFrames.filter(f => f.type === 'session/queued')).toEqual(liveFrames)
  })

  it('retires mirror entries on their terminal dequeue', async () => {
    const ctx = await harness()
    const api = createApiProxy(ctx, DEFAULTS)
    const agent = stubAgent(ctx)
-    const queued = inboxMessage('m-3', 'x', false)
-    const steering = inboxMessage('m-4', 'x', true, 'r-1')
-    ctx.emit('agent/inbox/enqueue', agent, queued)
-    ctx.emit('agent/inbox/enqueue', agent, steering)
+    const queued = inboxMessage('m-3', 'x')
+    const steering = inboxMessage('m-4', 'x', 'r-1')
+    ctx.emit('agent/inbox/enqueue', agent, queued, 'queued')
+    ctx.emit('agent/inbox/enqueue', agent, steering, 'steering')
    ctx.emit('agent/inbox/dequeue', agent, queued)
    ctx.emit('agent/inbox/dequeue', agent, steering)

@@ -298,10 +295,10 @@ describe('session/queued frames', () => {
    const ctx = await harness()
    const api = createApiProxy(ctx, DEFAULTS)
    const agent = stubAgent(ctx)
-    const doomed = inboxMessage('m-5', 'doomed', false)
-    const survivor = inboxMessage('m-6', 'survivor', false)
-    ctx.emit('agent/inbox/enqueue', agent, doomed)
-    ctx.emit('agent/inbox/enqueue', agent, survivor)
+    const doomed = inboxMessage('m-5', 'doomed')
+    const survivor = inboxMessage('m-6', 'survivor')
+    ctx.emit('agent/inbox/enqueue', agent, doomed, 'queued')
+    ctx.emit('agent/inbox/enqueue', agent, survivor, 'queued')
    ctx.emit('agent/inbox/discard', agent, [doomed])

    const abort = new AbortController()
--- a/packages/host/apiproxy/tests/api-proxy-models.spec.ts
+++ b/packages/host/apiproxy/tests/api-proxy-models.spec.ts
@@ -0,0 +1,233 @@
+/**
+ * Web session model-directory and selection behavior: dynamic provider grouping,
+ * provider-local catalog failures, logged-target restoration, advisory unlisted
+ * models, and the prompt-assembly boundary for a running selection change.
+ */
+
+import { describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import AgentRegistry, { agentEvents } from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
+import LlmService, { LlmAdapter, ReasoningEffortId } from '@deepseek-ai/dsh-llm'
+import type {
+  GenerateOptions, LlmCallConfig, LlmModelInfo, LlmModelReasoningInfo, LlmProviderInfo,
+  LlmResolvedModelInfo, StreamChunk,
+} from '@deepseek-ai/dsh-llm'
+import SessionStore from '@deepseek-ai/dsh-session'
+import type { SessionId } from '@deepseek-ai/dsh-session'
+import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
+import UserInteractionService from '@deepseek-ai/dsh-user-interaction'
+import type { RpcRequest } from '@deepseek-ai/dsh-host-apiproxy/api/rpc'
+import { RpcId } from '@deepseek-ai/dsh-host-apiproxy/api/rpc'
+import { createApiProxy } from '../src/api-proxy.ts'
+
+let nextRpc = 1
+function request<P>(payload: P): RpcRequest<P> {
+  return { rpcId: RpcId(`models-${String(nextRpc++)}`), payload }
+}
+
+class CatalogAdapter extends LlmAdapter {
+  constructor(
+    private readonly name: string,
+    private readonly models: readonly LlmModelInfo[] | Error,
+    private readonly reasoning?: LlmModelReasoningInfo,
+    private readonly exactError?: Error,
+  ) {
+    super()
+  }
+
+  override providerInfo(provider: string): LlmProviderInfo {
+    return { id: provider, name: this.name }
+  }
+
+  override listModels(): Promise<readonly LlmModelInfo[]> {
+    return this.models instanceof Error
+      ? Promise.reject(this.models)
+      : Promise.resolve(this.models)
+  }
+
+  override resolveModel(provider: string, model: string): Promise<LlmResolvedModelInfo> {
+    if (this.exactError !== undefined) return Promise.reject(this.exactError)
+    return Promise.resolve({
+      provider,
+      id: model,
+      name: model,
+      ...this.reasoning === undefined ? {} : { reasoning: this.reasoning },
+    })
+  }
+
+  override async *stream(_options: GenerateOptions): AsyncIterable<StreamChunk> {
+    // Catalog tests never enter provider streaming.
+  }
+}
+
+const REASONING: LlmModelReasoningInfo = {
+  efforts: [
+    { id: ReasoningEffortId('off'), name: 'Off' },
+    { id: ReasoningEffortId('high'), name: 'High' },
+    { id: ReasoningEffortId('max'), name: 'Max' },
+  ],
+  defaultEffort: ReasoningEffortId('high'),
+}
+
+async function harness(logged?: {
+  provider: string
+  model: string
+  reasoningEffort?: ReasoningEffortId
+}): Promise<{
+  ctx: Context
+  agent: Agent
+  sessionId: SessionId
+}> {
+  const ctx = new Context()
+  await ctx.plugin(SessionStore)
+  await ctx.plugin(SystemPrompt, { persona: '' })
+  await ctx.plugin(LlmService)
+  await ctx.plugin(UserInteractionService)
+  await ctx.plugin(AgentRegistry)
+  ctx.llm.registerAdapter(['deepseek'], new CatalogAdapter('DeepSeek', [
+    { provider: 'deepseek', id: 'deepseek-chat', name: 'DeepSeek Chat' },
+    { provider: 'deepseek', id: 'deepseek-reasoner', name: 'DeepSeek Reasoner', description: 'Reasoning model' },
+  ], REASONING))
+  ctx.llm.registerAdapter(['broken'], new CatalogAdapter('Broken Provider', new Error('catalog offline')))
+  ctx.llm.registerAdapter(['metadata-broken'], new CatalogAdapter('Metadata Broken', [
+    { provider: 'metadata-broken', id: 'listed', name: 'Listed' },
+  ], undefined, new Error('reasoning metadata offline')))
+  ctx.llm.registerAdapter(['empty'], new CatalogAdapter('Empty Provider', []))
+  ctx.llm.registerAdapter(['duplicate'], new CatalogAdapter('Duplicate Provider', [
+    { provider: 'duplicate', id: 'same', name: 'Same' },
+    { provider: 'duplicate', id: 'same', name: 'Same Again' },
+  ]))
+  const session = ctx.sessions.create()
+  if (logged !== undefined) {
+    session.append('request/header', { header: { config: logged }, reason: 'initial' })
+  }
+  const agent = {
+    id: session.id,
+    session,
+    status: 'running',
+    ctx,
+  } as Agent
+  ctx.agents.register(agent)
+  return { ctx, agent, sessionId: session.id }
+}
+
+function expectValue<T>(response: { result: { ok: true; value: T } | { ok: false } }): T {
+  if (!response.result.ok) throw new Error('expected successful response')
+  return response.result.value
+}
+
+describe('Web session model selection', () => {
+  it('groups successful providers, isolates failures, and preserves an unlisted current model', async () => {
+    const { ctx, sessionId } = await harness({
+      provider: 'deepseek',
+      model: 'private-preview',
+      reasoningEffort: ReasoningEffortId('max'),
+    })
+    const api = createApiProxy(ctx, { provider: 'deepseek', model: 'deepseek-chat', cwd: '/tmp', workspaceRoot: '/tmp' })
+
+    const catalog = expectValue(await api.sessions.models(request({ sessionId })))
+    expect(catalog.current).toEqual({
+      provider: 'deepseek',
+      model: 'private-preview',
+      reasoningEffort: 'max',
+    })
+    expect(catalog.groups).toEqual([{
+      id: 'deepseek',
+      name: 'DeepSeek',
+      models: [
+        { id: 'deepseek-chat', name: 'DeepSeek Chat', reasoning: REASONING },
+        {
+          id: 'deepseek-reasoner',
+          name: 'DeepSeek Reasoner',
+          description: 'Reasoning model',
+          reasoning: REASONING,
+        },
+        {
+          id: 'private-preview',
+          name: 'private-preview',
+          unlisted: true,
+          reasoning: REASONING,
+        },
+      ],
+    }])
+    expect(catalog.failures).toEqual([
+      { id: 'broken', name: 'Broken Provider', message: 'catalog offline' },
+      { id: 'metadata-broken', name: 'Metadata Broken', message: 'reasoning metadata offline' },
+      {
+        id: 'duplicate',
+        name: 'Duplicate Provider',
+        message: 'adapter returned invalid or duplicate model metadata for provider "duplicate"',
+      },
+    ])
+    await ctx.fiber.dispose()
+  })
+
+  it('accepts an advisory-unlisted model, rejects an unavailable provider, and switches only after the next assembly', async () => {
+    const { ctx, agent, sessionId } = await harness()
+    const api = createApiProxy(ctx, { provider: 'deepseek', model: 'deepseek-chat', cwd: '/tmp', workspaceRoot: '/tmp' })
+    const seed: LlmCallConfig = { provider: 'seed', model: 'seed', temperature: 0.2 }
+    const signal = new AbortController().signal
+
+    expect(expectValue(await api.sessions.models(request({ sessionId }))).current)
+      .toEqual({ provider: 'deepseek', model: 'deepseek-chat' })
+    expect((await ctx.systemPrompt.assemble()).variables)
+      .toMatchObject({ provider: 'deepseek', model: 'deepseek-chat' })
+
+    const selected = expectValue(await api.sessions.selectModel(request({
+      sessionId,
+      provider: 'deepseek',
+      model: 'private-preview',
+      reasoningEffort: 'max',
+    })))
+    expect(selected.selected).toEqual({
+      provider: 'deepseek',
+      model: 'private-preview',
+      reasoningEffort: 'max',
+    })
+    await expect(agentEvents(ctx, agent).waterfall(
+      'agent/request', 1, 0, signal, () => Promise.resolve(seed),
+    )).resolves.toMatchObject({ provider: 'deepseek', model: 'deepseek-chat' })
+
+    expect((await ctx.systemPrompt.assemble()).variables)
+      .toMatchObject({ provider: 'deepseek', model: 'private-preview' })
+    await expect(agentEvents(ctx, agent).waterfall(
+      'agent/request', 1, 1, signal, () => Promise.resolve(seed),
+    )).resolves.toMatchObject({
+      provider: 'deepseek',
+      model: 'private-preview',
+      reasoningEffort: 'max',
+    })
+
+    const unsupported = await api.sessions.selectModel(request({
+      sessionId,
+      provider: 'deepseek',
+      model: 'private-preview',
+      reasoningEffort: 'medium',
+    }))
+    expect(unsupported.result).toMatchObject({
+      ok: false,
+      error: {
+        code: 'model-unavailable',
+        message: 'provider "deepseek" model "private-preview" does not support reasoning effort "medium"',
+      },
+    })
+
+    const rejected = await api.sessions.selectModel(request({
+      sessionId,
+      provider: 'missing',
+      model: 'model',
+    }))
+    expect(rejected.result).toEqual({
+      ok: false,
+      error: {
+        code: 'model-unavailable',
+        message: 'no adapter registered for provider "missing"',
+        details: { provider: 'missing', model: 'model' },
+      },
+    })
+    expect(expectValue(await api.sessions.models(request({ sessionId }))).current)
+      .toEqual({ provider: 'deepseek', model: 'private-preview', reasoningEffort: 'max' })
+    await ctx.fiber.dispose()
+  })
+})
--- a/packages/host/apiproxy/tests/api-proxy-workspace.spec.ts
+++ b/packages/host/apiproxy/tests/api-proxy-workspace.spec.ts
@@ -43,9 +43,9 @@ function stubAgent(session: Session): Agent {
    options: {},
    session,
    status: 'idle',
+    acceptsNextStep: false,
    ctx: new Context(),
    followup: () => AgentMessageId('stub'),
-    queue: () => AgentMessageId('stub'),
    steer: () => AgentMessageId('stub'),
    inject: () => AgentMessageId('stub'),
    send: () => AgentMessageId('stub'),
@@ -57,6 +57,7 @@ function stubAgent(session: Session): Agent {
 /** Compose the API over real Session, Agent, Storage, Domain, and Workspace services. */
 async function harness(
  workspaceRoot = realpathSync(mkdtempSync(join(tmpdir(), 'dsh-apiproxy-workspace-'))),
+  pickDirectory?: (signal: AbortSignal) => Promise<string | null>,
 ) {
  const ctx = new Context()
  await ctx.plugin(SessionStore)
@@ -96,10 +97,33 @@ async function harness(
    model: 'test-model',
    cwd: workspaceRoot,
    workspaceRoot,
+    ...pickDirectory === undefined ? {} : { pickDirectory },
  })
  return { api, ctx, storageDomain, workspaceRoot }
 }

+describe('host.pickDirectory', () => {
+  it('returns a selected path or explicit cancellation from the injected native boundary', async () => {
+    const selected = await harness(undefined, async () => '/tmp/project')
+    expect((await selected.api.host.pickDirectory(request({}), new AbortController().signal)).result)
+      .toEqual({ ok: true, value: { path: '/tmp/project' } })
+
+    const cancelled = await harness(undefined, async () => null)
+    expect((await cancelled.api.host.pickDirectory(request({}), new AbortController().signal)).result)
+      .toEqual({ ok: true, value: { path: null } })
+  })
+
+  it('propagates abort into the native boundary as a cancelled RPC error', async () => {
+    const { api } = await harness(undefined, signal => new Promise((_resolve, reject) => {
+      signal.addEventListener('abort', () => { reject(new Error('aborted')) }, { once: true })
+    }))
+    const abort = new AbortController()
+    const pending = api.host.pickDirectory(request({}), abort.signal)
+    abort.abort()
+    expect((await pending).result).toMatchObject({ ok: false, error: { code: 'cancelled' } })
+  })
+})
+
 describe('workspace.create', () => {
  it('serializes concurrent names and rejects the duplicate', async () => {
    const { api, workspaceRoot } = await harness()
@@ -131,6 +155,13 @@ describe('workspace.create', () => {
    expect(first).toMatchObject({ created: true, workspace: { path: existing, title: 'existing' } })
    expect(repeated).toMatchObject({ created: false, workspace: { workspaceId: first.workspace.workspaceId } })

+    expectOk(await api.workspace.rename(request({
+      workspaceId: first.workspace.workspaceId,
+      title: 'renamed-existing',
+    })))
+    const reopened = expectOk(await api.workspace.create(request({ path: existing })))
+    expect(reopened.workspace.title).toBe('renamed-existing')
+
    const missing = join(workspaceRoot, 'missing')
    const missingResult = await api.workspace.create(request({ path: missing }))
    expect(missingResult.result).toMatchObject({ ok: false, error: { code: 'workspace-invalid-path' } })
@@ -141,6 +172,20 @@ describe('workspace.create', () => {
      expect(invalid.result).toMatchObject({ ok: false, error: { code: 'workspace-invalid-path' } })
    }
  })
+
+  it('rejects different paths that derive the same Workspace title', async () => {
+    const { api, workspaceRoot } = await harness()
+    const first = join(workspaceRoot, 'one', 'project')
+    const second = join(workspaceRoot, 'two', 'project')
+    mkdirSync(first, { recursive: true })
+    mkdirSync(second, { recursive: true })
+    expectOk(await api.workspace.create(request({ path: first })))
+    const conflict = await api.workspace.create(request({ path: second }))
+    expect(conflict.result).toMatchObject({
+      ok: false,
+      error: { code: 'workspace-name-conflict', details: { name: 'project' } },
+    })
+  })
 })

 describe('session creation and Workspace membership', () => {
--- a/packages/host/apiproxy/tests/client-handler.spec.ts
+++ b/packages/host/apiproxy/tests/client-handler.spec.ts
@@ -31,12 +31,28 @@ function scriptedApi(overrides: {
      list: r => ok(r, { items: [] }),
      search: r => ok(r, { items: [], hasMore: false }),
      create: r => ok(r, { sessionId: sid('s-new') }),
-      history: r => ok(r, { events: [], hasMore: false }),
+      history: r => ok(r, {
+        events: [],
+        hasMore: false,
+        modelTarget: { provider: 'deepseek', model: 'deepseek-v4-flash' },
+      }),
+      models: r => ok(r, {
+        current: { provider: 'deepseek', model: 'deepseek-v4-flash' },
+        groups: [],
+        failures: [],
+      }),
+      selectModel: r => ok(r, {
+        selected: { provider: r.payload.provider, model: r.payload.model },
+      }),
      prompt: r => ok(r, { accepted: true as const }),
      cancel: r => ok(r, { accepted: true as const }),
      ...overrides.sessions,
    },
-    host: { describe: r => ok(r, { version: '0-test', cwd: '/t', attachedSessions: 0 }), ...overrides.host },
+    host: {
+      describe: r => ok(r, { version: '0-test', cwd: '/t', attachedSessions: 0 }),
+      pickDirectory: r => ok(r, { path: null }),
+      ...overrides.host,
+    },
    workspace: {
      list: r => ok(r, { items: [] }),
      create: r => ok(r, { workspace: { workspaceId: 'w1' as never, path: '/t', title: 't', sessionIds: [], createdAt: '0', updatedAt: '0' }, created: true }),
--- a/packages/host/apiproxy/tests/fetch-carrier.spec.ts
+++ b/packages/host/apiproxy/tests/fetch-carrier.spec.ts
@@ -56,6 +56,36 @@ function fakeApi(overrides: Partial<{ muxFrames: MuxFrame[]; hostFrames: HostFra
          result: { ok: false, error: { code: 'session-not-found', message: 'nope', details: { sessionId: request.payload.sessionId } } },
        }
      },
+      async models(request) {
+        return {
+          rpcId: request.rpcId,
+          result: {
+            ok: true,
+            value: {
+              current: { provider: 'deepseek', model: 'deepseek-v4-flash' },
+              groups: [],
+              failures: [],
+            },
+          },
+        }
+      },
+      async selectModel(request) {
+        return {
+          rpcId: request.rpcId,
+          result: {
+            ok: true,
+            value: {
+              selected: {
+                provider: request.payload.provider,
+                model: request.payload.model,
+                ...request.payload.reasoningEffort === undefined
+                  ? {}
+                  : { reasoningEffort: request.payload.reasoningEffort },
+              },
+            },
+          },
+        }
+      },
      async prompt(request) {
        return { rpcId: request.rpcId, result: { ok: true, value: { accepted: true as const } } }
      },
@@ -67,6 +97,9 @@ function fakeApi(overrides: Partial<{ muxFrames: MuxFrame[]; hostFrames: HostFra
      async describe(request) {
        return { rpcId: request.rpcId, result: { ok: true, value: { version: 'v', cwd: '/w', attachedSessions: 0 } } }
      },
+      async pickDirectory(request) {
+        return { rpcId: request.rpcId, result: { ok: true, value: { path: null } } }
+      },
    },
    workspace: {
      async list(request) {
@@ -128,8 +161,8 @@ function fakeApi(overrides: Partial<{ muxFrames: MuxFrame[]; hostFrames: HostFra
  }
 }

-function client(api: ApiProxy = fakeApi()): InProcessApiClient {
-  return new InProcessApiClient(toFetchHandler(api))
+function client(api: ApiProxy = fakeApi(), timeoutMs?: number): InProcessApiClient {
+  return new InProcessApiClient(toFetchHandler(api), timeoutMs)
 }

 async function collect<F>(stream: AsyncIterable<RpcRequest<F>>): Promise<RpcRequest<F>[]> {
@@ -164,11 +197,38 @@ describe('unary round trip (handler ⇄ client, no network)', () => {
      value: { items: [{ sessionId: 's1', snippet: 'fixture match' }], hasMore: false },
    })
    expect((await c.sessions.create({})).result.ok).toBe(true)
+    expect((await c.sessions.models({ sessionId: 's' as never })).result.ok).toBe(true)
+    const selected = await c.sessions.selectModel({
+      sessionId: 's' as never,
+      provider: 'deepseek',
+      model: 'deepseek-v4-flash',
+      reasoningEffort: 'max',
+    })
+    expect(selected.result).toMatchObject({
+      ok: true,
+      value: {
+        selected: {
+          provider: 'deepseek',
+          model: 'deepseek-v4-flash',
+          reasoningEffort: 'max',
+        },
+      },
+    })
    expect((await c.sessions.prompt({ sessionId: 's' as never, mode: 'queue', content: [{ type: 'text', text: 'x' }] })).result.ok).toBe(true)
    expect((await c.sessions.cancel({ sessionId: 's' as never })).result.ok).toBe(true)
    expect((await c.host.describe({})).result.ok).toBe(true)
  })

+  it('round-trips the native picker without the default unary timeout', async () => {
+    const api = fakeApi()
+    api.host.pickDirectory = async (request) => {
+      await new Promise(resolve => setTimeout(resolve, 15))
+      return { rpcId: request.rpcId, result: { ok: true, value: { path: '/tmp/project' } } }
+    }
+    const response = await client(api, 1).host.pickDirectory({})
+    expect(response.result).toEqual({ ok: true, value: { path: '/tmp/project' } })
+  })
+
  it('round-trips command.list / command.execute / skill.list through the wire form', async () => {
    const c = client()
    const list = await c.commands.list({ sessionId: 's' as never })
@@ -217,6 +277,30 @@ describe('unary round trip (handler ⇄ client, no network)', () => {
    expect(parsed.rpcId).toBe('r-search-sig')
    expect(parsed.result.error?.code).toBe('cancelled')
  })
+
+  it('propagates the carrier Request signal into host.pickDirectory', async () => {
+    const api = fakeApi()
+    api.host.pickDirectory = async (request, signal) => {
+      if (!signal.aborted) {
+        await new Promise<void>((resolve) => {
+          signal.addEventListener('abort', () => { resolve() }, { once: true })
+        })
+      }
+      return {
+        rpcId: request.rpcId,
+        result: { ok: false, error: { code: 'cancelled', message: 'aborted', details: {} } },
+      }
+    }
+    const handler = toFetchHandler(api)
+    const controller = new AbortController()
+    const body = JSON.stringify({ type: 'client-request', rpcId: 'r-picker', method: 'host.pickDirectory', payload: {} })
+    const pending = handler.fetch(new Request('http://x/api/host.pickDirectory', {
+      method: 'POST', body, signal: controller.signal,
+    }))
+    controller.abort()
+    const parsed = await (await pending).json() as { result: { error?: { code: string } } }
+    expect(parsed.result.error?.code).toBe('cancelled')
+  })
 })

 describe('handler carrier-layer statuses', () => {
--- a/packages/host/apiproxy/tests/native-directory-picker.spec.ts
+++ b/packages/host/apiproxy/tests/native-directory-picker.spec.ts
@@ -0,0 +1,139 @@
+type ExecFileCallback = (
+  error: (Error & { code?: string | number }) | null,
+  stdout: string,
+  stderr: string,
+) => void
+type ExecFileMock = (
+  command: string,
+  args: readonly string[],
+  options: { encoding: string; signal: AbortSignal; windowsHide: boolean },
+  callback: ExecFileCallback,
+) => void
+
+const { execFileMock } = vi.hoisted(() => ({ execFileMock: vi.fn<ExecFileMock>() }))
+
+vi.mock('node:child_process', () => ({ execFile: execFileMock }))
+
+import { describe, expect, it, vi } from 'vitest'
+import { pickNativeDirectory, type DirectoryPickerRunner } from '../src/native-directory-picker.ts'
+
+function failure(code: string | number, stderr = ''): Error {
+  return Object.assign(new Error(`command failed: ${String(code)}`), { code, stderr })
+}
+
+const signal = () => new AbortController().signal
+
+describe('native directory picker', () => {
+  it('uses the macOS folder chooser and maps user cancellation to null', async () => {
+    const run = vi.fn<DirectoryPickerRunner>(async () => ({ stdout: '/Users/test/project/\n', stderr: '' }))
+    await expect(pickNativeDirectory(signal(), { platform: 'darwin', run })).resolves.toBe('/Users/test/project/')
+    expect(run).toHaveBeenCalledWith('osascript', expect.arrayContaining(['POSIX path of selectedFolder']), expect.any(AbortSignal))
+
+    run.mockRejectedValueOnce(failure(1, 'execution error: User canceled. (-128)'))
+    await expect(pickNativeDirectory(signal(), { platform: 'darwin', run })).resolves.toBeNull()
+
+    run.mockRejectedValueOnce(failure(2, 'permission denied'))
+    await expect(pickNativeDirectory(signal(), { platform: 'darwin', run })).rejects.toThrow('command failed')
+  })
+
+  it.each([
+    ['a primitive error', 'failed'],
+    ['an invalid code type', { code: true }],
+    ['a missing stderr property', { code: 1 }],
+    ['a non-string stderr property', { code: 1, stderr: 42 }],
+  ])('does not mistake %s for macOS cancellation', async (_label, reason) => {
+    const run = vi.fn<DirectoryPickerRunner>(async () => { throw reason })
+    await expect(pickNativeDirectory(signal(), { platform: 'darwin', run })).rejects.toBe(reason)
+  })
+
+  it('uses the Windows STA folder dialog and maps empty output to cancellation', async () => {
+    const run = vi.fn<DirectoryPickerRunner>(async () => ({ stdout: 'C:\\work\\project\r\n', stderr: '' }))
+    await expect(pickNativeDirectory(signal(), { platform: 'win32', run })).resolves.toBe('C:\\work\\project')
+    expect(run).toHaveBeenCalledWith(
+      'powershell.exe',
+      expect.arrayContaining(['-NoProfile', '-STA', '-Command']),
+      expect.any(AbortSignal),
+    )
+    expect(run.mock.calls[0]?.[1].at(-1)).toContain("$ErrorActionPreference = 'Stop'")
+    run.mockResolvedValueOnce({ stdout: '', stderr: '' })
+    await expect(pickNativeDirectory(signal(), { platform: 'win32', run })).resolves.toBeNull()
+    run.mockRejectedValueOnce(failure(1, 'Add-Type failed'))
+    await expect(pickNativeDirectory(signal(), { platform: 'win32', run })).rejects.toThrow('command failed')
+  })
+
+  it('runs the default command adapter without a shell and preserves command failures', async () => {
+    execFileMock.mockImplementationOnce((_command, _args, _options, callback) => {
+      callback(null, 'C:\\work\\default\r\n', '')
+    })
+    await expect(pickNativeDirectory(signal(), { platform: 'win32' })).resolves.toBe('C:\\work\\default')
+    const [command, args, options] = execFileMock.mock.calls[0]!
+    expect(command).toBe('powershell.exe')
+    expect(args).toEqual(expect.arrayContaining(['-NoProfile', '-STA', '-Command']))
+    expect(options.encoding).toBe('utf8')
+    expect(options.windowsHide).toBe(true)
+    expect(options.signal).toBeInstanceOf(AbortSignal)
+
+    const commandError = Object.assign(new Error('powershell failed'), { code: 7 })
+    execFileMock.mockImplementationOnce((_command, _args, _options, callback) => {
+      callback(commandError, 'partial output', 'failure details')
+    })
+    await expect(pickNativeDirectory(signal(), { platform: 'win32' })).rejects.toMatchObject({
+      message: 'powershell failed', cause: commandError, code: 7,
+      stdout: 'partial output', stderr: 'failure details',
+    })
+  })
+
+  it('uses the current process platform when no platform override is supplied', async () => {
+    const run = vi.fn<DirectoryPickerRunner>(async () => ({ stdout: '/default/platform\n', stderr: '' }))
+    await expect(pickNativeDirectory(signal(), { run })).resolves.toBe('/default/platform')
+  })
+
+  it('uses Zenity on Linux and falls back to KDialog only when Zenity is missing', async () => {
+    const run = vi.fn<DirectoryPickerRunner>()
+      .mockRejectedValueOnce(failure('ENOENT'))
+      .mockResolvedValueOnce({ stdout: '/home/test/project\n', stderr: '' })
+    await expect(pickNativeDirectory(signal(), { platform: 'linux', run })).resolves.toBe('/home/test/project')
+    expect(run.mock.calls.map(call => call[0])).toEqual(['zenity', 'kdialog'])
+
+    const zenity = vi.fn<DirectoryPickerRunner>(async () => ({ stdout: '/home/test/direct\n', stderr: '' }))
+    await expect(pickNativeDirectory(signal(), { platform: 'linux', run: zenity }))
+      .resolves.toBe('/home/test/direct')
+    expect(zenity).toHaveBeenCalledOnce()
+  })
+
+  it('maps Linux cancellation to null and reports a missing desktop picker', async () => {
+    const cancelled = vi.fn<DirectoryPickerRunner>(async () => { throw failure(1) })
+    await expect(pickNativeDirectory(signal(), { platform: 'linux', run: cancelled })).resolves.toBeNull()
+
+    const missing = vi.fn<DirectoryPickerRunner>(async () => { throw failure('ENOENT') })
+    await expect(pickNativeDirectory(signal(), { platform: 'linux', run: missing }))
+      .rejects.toThrow('install zenity or kdialog')
+
+    const kdialogCancelled = vi.fn<DirectoryPickerRunner>()
+      .mockRejectedValueOnce(failure('ENOENT'))
+      .mockRejectedValueOnce(failure(1))
+    await expect(pickNativeDirectory(signal(), { platform: 'linux', run: kdialogCancelled }))
+      .resolves.toBeNull()
+
+    const zenityFailed = vi.fn<DirectoryPickerRunner>(async () => { throw failure(2) })
+    await expect(pickNativeDirectory(signal(), { platform: 'linux', run: zenityFailed }))
+      .rejects.toThrow('command failed')
+
+    const kdialogFailed = vi.fn<DirectoryPickerRunner>()
+      .mockRejectedValueOnce(failure('ENOENT'))
+      .mockRejectedValueOnce(failure(2))
+    await expect(pickNativeDirectory(signal(), { platform: 'linux', run: kdialogFailed }))
+      .rejects.toThrow('command failed')
+  })
+
+  it('does not convert caller aborts into user cancellation', async () => {
+    const abort = new AbortController()
+    abort.abort(new Error('closed'))
+    const run = vi.fn<DirectoryPickerRunner>(async () => { throw failure('ABORT_ERR') })
+    await expect(pickNativeDirectory(abort.signal, { platform: 'linux', run })).rejects.toThrow('command failed')
+  })
+
+  it('reports unsupported platforms', async () => {
+    await expect(pickNativeDirectory(signal(), { platform: 'aix' })).rejects.toThrow('unsupported on aix')
+  })
+})
--- a/packages/host/apiproxy/tests/rpc-schemas.spec.ts
+++ b/packages/host/apiproxy/tests/rpc-schemas.spec.ts
@@ -8,8 +8,10 @@ import { z } from 'zod'
 import {
  contentBlockSchema, sessionCancelRequestSchema, sessionCancelValueSchema, sessionCreateRequestSchema,
  sessionCreateValueSchema, sessionEventSchema, sessionHistoryRequestSchema, sessionHistoryValueSchema,
-  sessionIdSchema, sessionListRequestSchema, sessionListValueSchema, sessionPromptRequestSchema,
-  sessionPromptValueSchema, sessionSearchRequestSchema, sessionSearchValueSchema, sessionSummarySchema,
+  sessionIdSchema, sessionListRequestSchema, sessionListValueSchema, sessionModelsRequestSchema,
+  sessionModelsValueSchema, sessionPromptRequestSchema, sessionPromptValueSchema,
+  sessionSearchRequestSchema, sessionSearchValueSchema, sessionSelectModelRequestSchema,
+  sessionSelectModelValueSchema, sessionSummarySchema,
 } from '../src/api/sessions.schema.ts'
 import { hostDescribeRequestSchema, hostDescribeValueSchema } from '../src/api/host.schema.ts'
 import {
@@ -56,6 +58,11 @@ describe('rpcErrorSchema', () => {
    expect(rpcErrorSchema.parse({ code: 'workspace-invalid-path', message: 'm', details: { path: '/x' } }).code).toBe('workspace-invalid-path')
    expect(rpcErrorSchema.parse({ code: 'workspace-name-conflict', message: 'm', details: { name: 'x' } }).code).toBe('workspace-name-conflict')
    expect(rpcErrorSchema.parse({ code: 'workspace-move-invalid', message: 'm', details: { workspaceId: 'w', sessionId: 's' } }).code).toBe('workspace-move-invalid')
+    expect(rpcErrorSchema.parse({
+      code: 'model-unavailable',
+      message: 'm',
+      details: { provider: 'p', model: 'm' },
+    }).code).toBe('model-unavailable')
    expect(rpcErrorSchema.parse({ code: 'agent-busy', message: 'm', details: { reason: 'r' } }).code).toBe('agent-busy')
    expect(rpcErrorSchema.parse({ code: 'internal', message: 'm', details: {} }).code).toBe('internal')
  })
@@ -159,7 +166,62 @@ describe('sessions domain schemas', () => {
    expect(sessionCreateValueSchema.parse({ sessionId: 's1' }).sessionId).toBe('s1')
    expect(sessionHistoryRequestSchema.parse({ sessionId: 's1', beforeSeq: 3, maxMessages: 5 }).beforeSeq).toBe(3)
    expect(() => sessionHistoryRequestSchema.parse({ sessionId: 's1', maxMessages: 0 })).toThrow()
-    expect(sessionHistoryValueSchema.parse({ events: [], hasMore: false }).hasMore).toBe(false)
+    expect(sessionHistoryValueSchema.parse({
+      events: [],
+      hasMore: false,
+      modelTarget: { provider: 'deepseek', model: 'deepseek-v4-flash' },
+    }).hasMore).toBe(false)
+    expect(sessionModelsRequestSchema.parse({ sessionId: 's1' }).sessionId).toBe('s1')
+    expect(sessionModelsValueSchema.parse({
+      current: { provider: 'deepseek', model: 'deepseek-v4-flash', reasoningEffort: 'max' },
+      groups: [{
+        id: 'deepseek',
+        name: 'DeepSeek',
+        models: [{
+          id: 'deepseek-v4-flash',
+          name: 'DeepSeek V4 Flash',
+          description: 'fast',
+          unlisted: true,
+          reasoning: {
+            efforts: [
+              { id: 'off', name: 'Off' },
+              { id: 'max', name: 'Max', description: 'Largest budget' },
+            ],
+            defaultEffort: 'off',
+          },
+        }],
+      }],
+      failures: [{ id: 'broken', name: 'Broken', message: 'offline' }],
+    }).groups[0]?.models[0]?.id).toBe('deepseek-v4-flash')
+    expect(sessionSelectModelRequestSchema.parse({
+      sessionId: 's1',
+      provider: 'deepseek',
+      model: 'deepseek-v4-pro',
+      reasoningEffort: 'max',
+    }).reasoningEffort).toBe('max')
+    expect(sessionSelectModelValueSchema.parse({
+      selected: { provider: 'deepseek', model: 'deepseek-v4-pro', reasoningEffort: 'max' },
+    }).selected.reasoningEffort).toBe('max')
+    expect(() => sessionSelectModelRequestSchema.parse({
+      sessionId: 's1',
+      provider: '',
+      model: 'm',
+    })).toThrow()
+    expect(() => sessionSelectModelRequestSchema.parse({
+      sessionId: 's1',
+      provider: 'deepseek',
+      model: 'm',
+      reasoningEffort: '',
+    })).toThrow()
+    expect(() => sessionModelsValueSchema.parse({
+      current: { provider: 'deepseek', model: 'm' },
+      groups: [{
+        id: 'deepseek',
+        name: 'DeepSeek',
+        models: [{ id: 'm', name: 'M', reasoning: { efforts: [] } }],
+      }],
+      failures: [],
+    })).toThrow()
    const prompt = sessionPromptRequestSchema.parse({ sessionId: 's1', mode: 'queue', content: [{ type: 'text', text: 'hi' }] })
    expect(prompt.mode).toBe('queue')
    expect(() => sessionPromptRequestSchema.parse({ sessionId: 's1', mode: 'inject', content: [] })).toThrow()
@@ -299,8 +361,8 @@ describe('events frame schemas', () => {
  })

  it('rejects a queued frame missing its members', () => {
-    expect(() => muxFrameSchema.parse({ type: 'session/queued', sessionId: 's', content: [{ type: 'text' }], source: { kind: 'user' } })).toThrow()
-    expect(() => muxFrameSchema.parse({ type: 'session/queued', sessionId: 's', content: 'x', source: { kind: 'user' }, steering: false })).toThrow()
+    expect(() => muxFrameSchema.parse({ type: 'session/queued', sessionId: 's', content: 'x', source: { kind: 'user' } })).toThrow()
+    expect(() => muxFrameSchema.parse({ type: 'session/queued', sessionId: 's', content: [], source: { kind: 'user' } })).toThrow()
    expect(() => muxFrameSchema.parse({ type: 'session/queued', sessionId: 's', content: [], source: {}, steering: false })).toThrow()
  })