feat(host): directory-picker capability seam with dialog and browse backends

The web GUI's folder picking was hardwired to one interaction: a native
OS chooser compiled into the gateway, unusable for remote deployments
and swappable only by editing apiproxy source.

Directory picking becomes a three-package capability seam in
packages/host: ctx.directoryPicker returns a discriminated capability —
dialog (the extracted native chooser; host-display only) or browse
(new: one-level listing + child creation over Node stdlib, hidden flags
host-stamped, symlinks followed, ancestry crumbs; remote-capable). The
gateway injects the seam, advertises the kind via
host.describe.directoryPicker, serves host.listDirectory /
host.createDirectory under browse, and answers
directory-picker-unavailable across kinds. cordis.yml is the swap
point; apps/cli keeps dialog mounted, so behavior is unchanged until
the in-app browser PR flips the default. The connection fixture serves
a deterministic browse tree; WorkspacesService gains the browse calls
the browser UI will drive. Decision record:
.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md

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: 2f51aa23e2639e2e98dfdd8aaf71e807d641c3dc
-README.zh.md: 687e60879702a762d9e85295789b77daea4bd4ac
+README.md: 7c53e6dc9ac5758fce91d8b39abbfab6641384d1
+README.zh.md: 5089935fe545bfc6ac3ddb39b9a2a25b50e1ceab

packages/host/apiproxy/README.md

@@ -16,7 +16,7 @@ Session model routing is a session-domain contract. `session.models` returns the
 
 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()`.
 
-`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's prefix-wide trust fence (dsh-client-connection) covers this method like every other `/api` request.
+Directory picking delegates to the composed `ctx.directoryPicker` backend ([the directory-picker seam](../directory-picker/README.md)); `host.describe.directoryPicker` advertises the capability kind the client renders for, and a method called outside the advertised kind fails with `directory-picker-unavailable`. Under `dialog`, `host.pickDirectory` opens one native chooser and returns its selected path (`null` on cancel); this user-paced method is the sole unary call exempt from the default 30-second timeout, and caller/connection aborts still propagate to the native process. Under `browse`, `host.listDirectory` returns one name-sorted directory level with breadcrumb ancestry, a `home` anchor, and host-owned `hidden` flags (absent path = home directory), and `host.createDirectory` creates one validated child segment; the backend's typed failures map 1:1 onto the `directory-unreadable`/`directory-exists`/`directory-create-failed` codes. The browser carrier's prefix-wide trust fence (dsh-client-connection) covers all of these like every other `/api` request.
 
 `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.
 
@@ -39,4 +39,4 @@ None; this package neither assembles nor sends a provider request.
 - **`respond` routing is shipped, but pending-interaction state is host-side work** — the wire shape (POST `/api/respond`, `RpcReceipt`) is final; the pending table that makes late/duplicate answers meaningful lives in `src/api-proxy.ts` and is still minimal (questions only, no approvals).
 - **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.
-- **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.
+- **Linux native picker requires desktop tooling** — under the `dialog` capability, `host.pickDirectory` reports an actionable error when neither Zenity nor KDialog is installed; the browse backend is the composition-level fallback (see the [dialog backend README](../directory-picker-dialog/README.md)).

packages/host/apiproxy/README.zh.md

@@ -16,7 +16,7 @@ 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
 
 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。
 
-`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。浏览器载体的前缀级信任栅栏（dsh-client-connection）像覆盖其他所有 `/api` 请求一样覆盖该方法。
+目录选择委托给组合的 `ctx.directoryPicker` 后端（[目录选择 seam](../directory-picker/README.md)）；`host.describe.directoryPicker` 广播客户端应按其渲染的能力 kind，调用广播之外的方法会以 `directory-picker-unavailable` 失败。在 `dialog` 下，`host.pickDirectory` 打开一个原生选择器并返回选中路径（取消为 `null`）；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，调用方与连接的中止仍会传播至原生进程。在 `browse` 下，`host.listDirectory` 返回一个按名称排序的目录层级，携带面包屑祖先链、`home` 锚点与宿主判定的 `hidden` 标志（不带路径即家目录），`host.createDirectory` 创建一个经校验的子段；后端的类型化失败 1:1 映射为 `directory-unreadable`／`directory-exists`／`directory-create-failed` 错误码。浏览器载体的前缀级信任栅栏（dsh-client-connection）像覆盖其他所有 `/api` 请求一样覆盖上述全部方法。
 
 `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」。
 
@@ -39,4 +39,4 @@ Workspace 列表与 Session 列表是相互独立的重连基线。`workspace.cr
 - **`respond` 路由已经发布，但待处理交互状态仍属宿主侧工作**：协议形状（POST `/api/respond`、`RpcReceipt`）已经定型；使延迟或重复回答具有明确语义的待处理表位于 `src/api-proxy.ts`，目前仍很精简（只支持问题，不支持审批）。
 - **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。
-- **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。
+- **Linux 原生选择器依赖桌面工具**：在 `dialog` 能力下，Zenity 和 KDialog 均未安装时，`host.pickDirectory` 会给出包含解决建议的错误提示；组合层面的回退是 browse 后端（见 [dialog 后端 README](../directory-picker-dialog/README.md)）。

packages/host/apiproxy/package.json

@@ -43,6 +43,7 @@
     "@deepseek-ai/dsh-agent": "workspace:^",
     "@deepseek-ai/dsh-brand": "workspace:^",
     "@deepseek-ai/dsh-commands": "workspace:^",
+    "@deepseek-ai/dsh-host-directory-picker": "workspace:^",
     "@deepseek-ai/dsh-llm": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",
     "@deepseek-ai/dsh-session-persistence": "workspace:^",

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

@@ -39,7 +39,7 @@ 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'
+import { DirectoryPickerError } from '@deepseek-ai/dsh-host-directory-picker'
 
 /** Page size when history is called without maxMessages. */
 const DEFAULT_MAX_MESSAGES = 50
@@ -193,6 +193,14 @@ async function summarizeCold(persistence: SessionPersistence, meta: SessionHeade
   }
 }
 
+/** Map a browse-primitive failure onto the wire error vocabulary (unknown throws stay internal). */
+function directoryError(error: unknown): RpcError {
+  if (error instanceof DirectoryPickerError) {
+    return { code: error.code, message: error.message, details: { path: error.path } }
+  }
+  return { code: 'internal', message: error instanceof Error ? error.message : String(error), details: {} }
+}
+
 /** Resolved Host routing and project-directory defaults consumed by the API implementation. */
 export interface ApiProxyDefaults {
   provider: string
@@ -201,8 +209,6 @@ 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. */
@@ -990,12 +996,21 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
           provider: defaults.provider,
           model: defaults.model,
           attachedSessions: ctx.agents.list().length,
+          directoryPicker: ctx.directoryPicker.capability().kind,
         }))
       },
 
       async pickDirectory(request, signal) {
+        const capability = ctx.directoryPicker.capability()
+        if (capability.kind !== 'dialog') {
+          return err(request, {
+            code: 'directory-picker-unavailable',
+            message: `host.pickDirectory needs the dialog capability; the composed picker serves "${capability.kind}"`,
+            details: { capability: capability.kind },
+          })
+        }
         try {
-          const path = await (defaults.pickDirectory ?? pickNativeDirectory)(signal)
+          const path = await capability.pick(signal)
           return ok(request, { path })
         } catch (error: unknown) {
           if (signal.aborted) {
@@ -1012,6 +1027,38 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
           })
         }
       },
+
+      async listDirectory(request) {
+        const capability = ctx.directoryPicker.capability()
+        if (capability.kind !== 'browse') {
+          return err(request, {
+            code: 'directory-picker-unavailable',
+            message: `host.listDirectory needs the browse capability; the composed picker serves "${capability.kind}"`,
+            details: { capability: capability.kind },
+          })
+        }
+        try {
+          return ok(request, await capability.list(request.payload.path))
+        } catch (error: unknown) {
+          return err(request, directoryError(error))
+        }
+      },
+
+      async createDirectory(request) {
+        const capability = ctx.directoryPicker.capability()
+        if (capability.kind !== 'browse') {
+          return err(request, {
+            code: 'directory-picker-unavailable',
+            message: `host.createDirectory needs the browse capability; the composed picker serves "${capability.kind}"`,
+            details: { capability: capability.kind },
+          })
+        }
+        try {
+          return ok(request, { path: await capability.createDirectory(request.payload.path, request.payload.name) })
+        } catch (error: unknown) {
+          return err(request, directoryError(error))
+        }
+      },
     },
 
     commands: {

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

@@ -3,6 +3,7 @@
  */
 
 import { z } from 'zod'
+import type { DirectoryEntry } from './host.ts'
 import type { RequestPayload, ResponseValue } from './rpc-map.ts'
 import type { Wire } from './rpc.schema.ts'
 
@@ -16,6 +17,7 @@ export const hostDescribeValueSchema = z.object({
   provider: z.string().optional(),
   model: z.string().optional(),
   attachedSessions: z.number().int().nonnegative(),
+  directoryPicker: z.union([z.literal('dialog'), z.literal('browse')]),
 }) satisfies z.ZodType<Wire<ResponseValue<'host.describe'>>>
 
 /** host.pickDirectory request payload (empty object literal). */
@@ -25,3 +27,38 @@ export const hostPickDirectoryRequestSchema = z.object({}) satisfies z.ZodType<W
 export const hostPickDirectoryValueSchema = z.object({
   path: z.string().nullable(),
 }) satisfies z.ZodType<Wire<ResponseValue<'host.pickDirectory'>>>
+
+/** Directory row shared by listing entries and breadcrumb crumbs. */
+export const directoryEntrySchema = z.object({
+  name: z.string(),
+  path: z.string(),
+  hidden: z.boolean(),
+}) satisfies z.ZodType<Wire<DirectoryEntry>>
+
+/** host.listDirectory request payload; an absent path lists the home directory. */
+export const hostListDirectoryRequestSchema = z.object({
+  path: z.string().optional(),
+}) satisfies z.ZodType<Wire<RequestPayload<'host.listDirectory'>>>
+
+/** host.listDirectory response value. */
+export const hostListDirectoryValueSchema = z.object({
+  path: z.string(),
+  home: z.string(),
+  crumbs: z.array(directoryEntrySchema),
+  entries: z.array(directoryEntrySchema),
+}) satisfies z.ZodType<Wire<ResponseValue<'host.listDirectory'>>>
+
+/** host.createDirectory request payload: name must be one plain path segment. */
+export const hostCreateDirectoryRequestSchema = z.object({
+  path: z.string(),
+  name: z.string(),
+}).refine(
+  payload => payload.name.trim() !== '' && payload.name !== '.' && payload.name !== '..'
+    && !/[/\\]/.test(payload.name),
+  { message: 'host.createDirectory requires a single non-blank path segment name' },
+) satisfies z.ZodType<Wire<RequestPayload<'host.createDirectory'>>>
+
+/** host.createDirectory response value: the created directory's absolute path. */
+export const hostCreateDirectoryValueSchema = z.object({
+  path: z.string(),
+}) satisfies z.ZodType<Wire<ResponseValue<'host.createDirectory'>>>

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

@@ -5,6 +5,40 @@
 
 import type { RpcRequest, RpcResponse } from './rpc.ts'
 
+/**
+ * The composed directory-picker interaction the host serves (mirror of the
+ * `ctx.directoryPicker` capability kind): `dialog` = one native OS chooser on
+ * the host display (`host.pickDirectory`); `browse` = in-app listing/creation
+ * primitives (`host.listDirectory`/`host.createDirectory`). Calling a method
+ * outside the advertised kind fails with `directory-picker-unavailable`.
+ */
+export type DirectoryPickerKind = 'dialog' | 'browse'
+
+/** One directory row of a listing: a child entry or a breadcrumb ancestor. */
+export interface DirectoryEntry {
+  /** Base name shown in a browser row (a root crumb carries its full path). */
+  name: string
+  /** Absolute host path — the client never joins path segments itself. */
+  path: string
+  /** Hidden by the host platform's convention (dot-prefixed on POSIX); the client owns whether to show it. */
+  hidden: boolean
+}
+
+/** host.listDirectory response value: one directory level plus its ancestry. */
+export interface DirectoryListing {
+  /** Absolute path of the listed directory. */
+  path: string
+  /** The host account's home directory (breadcrumb "Home" rooting). */
+  home: string
+  /**
+   * Ancestor chain from the filesystem root to the listed directory
+   * inclusive; every crumb is a jump target (crumb `hidden` is always false).
+   */
+  crumbs: DirectoryEntry[]
+  /** Direct child directories, name-sorted; symlinks to directories included. */
+  entries: DirectoryEntry[]
+}
+
 /** Host-level unary methods. */
 export interface HostApi {
   /**
@@ -13,7 +47,8 @@ export interface HostApi {
    * directory (root for session persistence and tool execution); provider/model = the defaults
    * applied when a new agent doesn't specify them explicitly, absent when the host configures
    * no explicit default (the adapter falls back internally);
-   * attachedSessions = count of currently attached sessions (those with a live agent).
+   * attachedSessions = count of currently attached sessions (those with a live agent);
+   * directoryPicker = the composed picker interaction the client renders for.
    */
   describe(request: RpcRequest<{}>): Promise<RpcResponse<{
     version: string
@@ -21,11 +56,34 @@ export interface HostApi {
     provider?: string
     model?: string
     attachedSessions: number
+    directoryPicker: DirectoryPickerKind
   }>>
 
-  /** Open the operating system's single-directory picker; cancellation returns null. */
+  /**
+   * Open the operating system's single-directory picker; cancellation returns
+   * null. Only served under the `dialog` capability.
+   */
   pickDirectory(
     request: RpcRequest<{}>,
     signal: AbortSignal,
   ): Promise<RpcResponse<{ path: string | null }>>
+
+  /**
+   * List one directory level for the in-app browser; an absent path lists the
+   * host account's home directory. Only served under the `browse` capability;
+   * unreadable or missing targets fail with `directory-unreadable`.
+   */
+  listDirectory(
+    request: RpcRequest<{ path?: string }>,
+  ): Promise<RpcResponse<DirectoryListing>>
+
+  /**
+   * Create one child directory under an existing parent (the browser's
+   * "New folder"). Only served under the `browse` capability; an existing
+   * child fails with `directory-exists`, every other filesystem failure with
+   * `directory-create-failed`.
+   */
+  createDirectory(
+    request: RpcRequest<{ path: string; name: string }>,
+  ): Promise<RpcResponse<{ path: string }>>
 }

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

@@ -29,7 +29,7 @@ export type {
   HistoryEntry, ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
   ModelReasoningEffort, ModelTarget, SessionModels, SessionsApi, SessionSummary,
 } from './sessions.ts'
-export type { HostApi } from './host.ts'
+export type { DirectoryEntry, DirectoryListing, DirectoryPickerKind, HostApi } from './host.ts'
 export type { WorkspaceApi, WorkspaceId, WorkspaceView } from './workspace.ts'
 export type { CommandsApi, CommandDescriptor, CommandExecuteResult } from './commands.ts'
 export type { SkillsApi, SkillEntry } from './skills.ts'

packages/host/apiproxy/src/api/rpc-map.ts

@@ -26,6 +26,8 @@ export interface RpcMethodMap {
   'session.cancel': SessionsApi['cancel']
   'host.describe': HostApi['describe']
   'host.pickDirectory': HostApi['pickDirectory']
+  'host.listDirectory': HostApi['listDirectory']
+  'host.createDirectory': HostApi['createDirectory']
   'workspace.list': WorkspaceApi['list']
   'workspace.create': WorkspaceApi['create']
   'workspace.rename': WorkspaceApi['rename']

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

@@ -42,6 +42,10 @@ export const rpcErrorSchema: z.ZodType<RpcError> = z.discriminatedUnion('code',
   z.object({ code: z.literal('workspace-invalid-path'), message: z.string(), details: z.object({ path: z.string() }) }),
   z.object({ code: z.literal('workspace-name-conflict'), message: z.string(), details: z.object({ name: z.string() }) }),
   z.object({ code: z.literal('workspace-move-invalid'), message: z.string(), details: z.object({ workspaceId: z.string(), sessionId: z.string(), beforeSessionId: z.string().optional() }) }),
+  z.object({ code: z.literal('directory-unreadable'), message: z.string(), details: z.object({ path: z.string() }) }),
+  z.object({ code: z.literal('directory-exists'), message: z.string(), details: z.object({ path: z.string() }) }),
+  z.object({ code: z.literal('directory-create-failed'), message: z.string(), details: z.object({ path: z.string() }) }),
+  z.object({ code: z.literal('directory-picker-unavailable'), message: z.string(), details: z.object({ capability: z.string() }) }),
   z.object({ code: z.literal('agent-busy'), message: z.string(), details: z.object({ reason: z.string() }) }),
   z.object({ code: z.literal('internal'), message: z.string(), details: z.object({}) }),
 ]) as unknown as z.ZodType<RpcError>

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

@@ -39,6 +39,10 @@ export interface RpcErrorDetailsMap {
   'workspace-invalid-path': { path: string }
   'workspace-name-conflict': { name: string }
   'workspace-move-invalid': { workspaceId: string; sessionId: SessionId; beforeSessionId?: SessionId }
+  'directory-unreadable': { path: string }
+  'directory-exists': { path: string }
+  'directory-create-failed': { path: string }
+  'directory-picker-unavailable': { capability: string }
   'agent-busy': { reason: string }
   'internal': {}
 }

packages/host/apiproxy/src/fetch/client.ts

@@ -13,7 +13,10 @@ 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, hostPickDirectoryValueSchema } from '../api/host.schema.ts'
+import {
+  hostCreateDirectoryValueSchema, hostDescribeValueSchema,
+  hostListDirectoryValueSchema, hostPickDirectoryValueSchema,
+} from '../api/host.schema.ts'
 import {
   sessionCancelValueSchema,
   sessionCreateValueSchema,
@@ -61,6 +64,8 @@ export interface IApiClient {
   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'>>>
+    listDirectory(payload: RequestPayload<'host.listDirectory'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'host.listDirectory'>>>
+    createDirectory(payload: RequestPayload<'host.createDirectory'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'host.createDirectory'>>>
   }
   workspace: {
     list(payload: RequestPayload<'workspace.list'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'workspace.list'>>>
@@ -98,6 +103,8 @@ const UNARY_VALUE_SCHEMAS: { [K in keyof RpcMethodMap]: z.ZodType<Wire<ResponseV
   'session.cancel': sessionCancelValueSchema,
   'host.describe': hostDescribeValueSchema,
   'host.pickDirectory': hostPickDirectoryValueSchema,
+  'host.listDirectory': hostListDirectoryValueSchema,
+  'host.createDirectory': hostCreateDirectoryValueSchema,
   'workspace.list': workspaceListValueSchema,
   'workspace.create': workspaceCreateValueSchema,
   'workspace.rename': workspaceRenameValueSchema,
@@ -305,6 +312,8 @@ export abstract class AbstractApiClient implements IApiClient {
     // 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),
+    listDirectory: (payload, signal) => this.callUnary('host.listDirectory', payload, signal),
+    createDirectory: (payload, signal) => this.callUnary('host.createDirectory', payload, signal),
   }
 
   readonly workspace: IApiClient['workspace'] = {

packages/host/apiproxy/src/fetch/handler.ts

@@ -23,7 +23,10 @@ import {
   sessionPromptRequestSchema,
   sessionSelectModelRequestSchema,
 } from '../api/sessions.schema.ts'
-import { hostDescribeRequestSchema, hostPickDirectoryRequestSchema } from '../api/host.schema.ts'
+import {
+  hostCreateDirectoryRequestSchema, hostDescribeRequestSchema,
+  hostListDirectoryRequestSchema, hostPickDirectoryRequestSchema,
+} from '../api/host.schema.ts'
 import {
   workspaceCreateRequestSchema,
   workspaceDeleteRequestSchema,
@@ -60,6 +63,8 @@ const UNARY_ROUTES: UnaryRoutes = {
   '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) },
+  'host.listDirectory': { schema: hostListDirectoryRequestSchema, invoke: (api, r) => api.host.listDirectory(r) },
+  'host.createDirectory': { schema: hostCreateDirectoryRequestSchema, invoke: (api, r) => api.host.createDirectory(r) },
   '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) },

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', 'llm', 'sessions', 'tools', 'userInteraction', 'workspace']
+  static inject = ['agents', 'directoryPicker', 'llm', 'sessions', 'tools', 'userInteraction', 'workspace']
 
   static Config: z<Config> = z.object({
     provider: z.string().required(),

packages/host/apiproxy/src/native-directory-picker.ts

@@ -1,136 +0,0 @@
-/** 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}`)
-}

packages/host/apiproxy/tests/api-proxy-workspace.spec.ts

@@ -10,6 +10,8 @@ import type { Session } from '@deepseek-ai/dsh-session'
 import Storage from '@deepseek-ai/dsh-storage'
 import { DomainFacility } from '@deepseek-ai/dsh-storage-domain'
 import UserInteractionService from '@deepseek-ai/dsh-user-interaction'
+import { DirectoryPickerError } from '@deepseek-ai/dsh-host-directory-picker'
+import type { DirectoryPickerCapability } from '@deepseek-ai/dsh-host-directory-picker'
 import WorkspaceRegistry from '@deepseek-ai/dsh-workspace'
 import type { HostFrame, WorkspaceId } from '@deepseek-ai/dsh-host-apiproxy/api'
 import type { RpcRequest, RpcResponse } from '@deepseek-ai/dsh-host-apiproxy/api/rpc'
@@ -57,7 +59,7 @@ 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>,
+  picker: DirectoryPickerCapability = { kind: 'dialog', pick: async () => null },
 ) {
   const ctx = new Context()
   await ctx.plugin(SessionStore)
@@ -92,36 +94,114 @@ async function harness(
     },
   }
   ctx.agents.setFactory(factory)
+  // Structural picker fake: the gateway only reads capability(); a stable
+  // object per harness mirrors the seam's stability contract.
+  ctx.provide('directoryPicker', { capability: () => picker } as never)
   const api = createApiProxy(ctx, {
     provider: 'test',
     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')
+  it('returns a selected path or explicit cancellation from the dialog capability', async () => {
+    const selected = await harness(undefined, { kind: 'dialog', pick: 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)
+    const cancelled = await harness(undefined, { kind: 'dialog', pick: 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 })
-    }))
+  it('propagates abort into the dialog capability as a cancelled RPC error', async () => {
+    const { api } = await harness(undefined, {
+      kind: 'dialog',
+      pick: 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' } })
   })
+
+  it('folds a non-abort dialog failure into an internal error', async () => {
+    const { api } = await harness(undefined, { kind: 'dialog', pick: async () => { throw new Error('no chooser installed') } })
+    const response = await api.host.pickDirectory(request({}), new AbortController().signal)
+    expect(response.result).toMatchObject({ ok: false, error: { code: 'internal' } })
+  })
+
+  it('refuses the dialog RPC under a browse composition', async () => {
+    const { api } = await harness(undefined, BROWSE_STUB)
+    const response = await api.host.pickDirectory(request({}), new AbortController().signal)
+    expect(response.result).toMatchObject({
+      ok: false,
+      error: { code: 'directory-picker-unavailable', details: { capability: 'browse' } },
+    })
+  })
+})
+
+/** Canned browse capability: one listing, one created path, typed failures on demand. */
+const BROWSE_STUB: DirectoryPickerCapability = {
+  kind: 'browse',
+  list: async (path) => {
+    if (path === '/denied') throw new DirectoryPickerError('directory-unreadable', '/denied', 'cannot list /denied')
+    const target = path ?? '/home/user'
+    return {
+      path: target,
+      home: '/home/user',
+      crumbs: [{ name: '/', path: '/', hidden: false }],
+      entries: [{ name: 'projects', path: `${target}/projects`, hidden: false }],
+    }
+  },
+  createDirectory: async (path, name) => {
+    if (name === 'taken') throw new DirectoryPickerError('directory-exists', `${path}/${name}`, 'already exists')
+    if (name === 'unwritable') throw new Error('disk detached')
+    return `${path}/${name}`
+  },
+}
+
+describe('host.listDirectory / host.createDirectory', () => {
+  it('serves listings and creation through the browse capability, defaulting to home', async () => {
+    const { api } = await harness(undefined, BROWSE_STUB)
+    const home = await api.host.listDirectory(request({}))
+    expect(home.result).toMatchObject({ ok: true, value: { path: '/home/user', home: '/home/user' } })
+    const listed = await api.host.listDirectory(request({ path: '/home/user/projects' }))
+    expect(listed.result).toMatchObject({ ok: true, value: { path: '/home/user/projects' } })
+    const created = await api.host.createDirectory(request({ path: '/home/user', name: 'fresh' }))
+    expect(created.result).toEqual({ ok: true, value: { path: '/home/user/fresh' } })
+  })
+
+  it('maps typed picker failures onto the wire error codes and folds unknown throws to internal', async () => {
+    const { api } = await harness(undefined, BROWSE_STUB)
+    expect((await api.host.listDirectory(request({ path: '/denied' }))).result).toMatchObject({
+      ok: false, error: { code: 'directory-unreadable', details: { path: '/denied' } },
+    })
+    expect((await api.host.createDirectory(request({ path: '/home/user', name: 'taken' }))).result).toMatchObject({
+      ok: false, error: { code: 'directory-exists' },
+    })
+    expect((await api.host.createDirectory(request({ path: '/home/user', name: 'unwritable' }))).result).toMatchObject({
+      ok: false, error: { code: 'internal' },
+    })
+  })
+
+  it('refuses the browse RPCs under a dialog composition and advertises the kind in describe', async () => {
+    const { api } = await harness()
+    expect((await api.host.describe(request({}))).result).toMatchObject({ ok: true, value: { directoryPicker: 'dialog' } })
+    expect((await api.host.listDirectory(request({}))).result).toMatchObject({
+      ok: false, error: { code: 'directory-picker-unavailable', details: { capability: 'dialog' } },
+    })
+    expect((await api.host.createDirectory(request({ path: '/x', name: 'y' }))).result).toMatchObject({
+      ok: false, error: { code: 'directory-picker-unavailable', details: { capability: 'dialog' } },
+    })
+    const browse = await harness(undefined, BROWSE_STUB)
+    expect((await browse.api.host.describe(request({}))).result).toMatchObject({ ok: true, value: { directoryPicker: 'browse' } })
+  })
 })
 
 describe('workspace.create', () => {

packages/host/apiproxy/tests/client-handler.spec.ts

@@ -48,8 +48,10 @@ function scriptedApi(overrides: {
       ...overrides.sessions,
     },
     host: {
-      describe: r => ok(r, { version: '0-test', cwd: '/t', attachedSessions: 0 }),
+      describe: r => ok(r, { version: '0-test', cwd: '/t', attachedSessions: 0, directoryPicker: 'browse' as const }),
       pickDirectory: r => ok(r, { path: null }),
+      listDirectory: r => ok(r, { path: '/t', home: '/t', crumbs: [], entries: [] }),
+      createDirectory: r => ok(r, { path: '/t/new' }),
       ...overrides.host,
     },
     workspace: {

packages/host/apiproxy/tests/fetch-carrier.spec.ts

@@ -75,11 +75,17 @@ function fakeApi(overrides: Partial<{ muxFrames: MuxFrame[]; hostFrames: HostFra
     },
     host: {
       async describe(request) {
-        return { rpcId: request.rpcId, result: { ok: true, value: { version: 'v', cwd: '/w', attachedSessions: 0 } } }
+        return { rpcId: request.rpcId, result: { ok: true, value: { version: 'v', cwd: '/w', attachedSessions: 0, directoryPicker: 'dialog' as const } } }
       },
       async pickDirectory(request) {
         return { rpcId: request.rpcId, result: { ok: true, value: { path: null } } }
       },
+      async listDirectory(request) {
+        return { rpcId: request.rpcId, result: { ok: true, value: { path: '/w', home: '/w', crumbs: [{ name: '/', path: '/', hidden: false }], entries: [] } } }
+      },
+      async createDirectory(request) {
+        return { rpcId: request.rpcId, result: { ok: true, value: { path: '/w/new' } } }
+      },
     },
     workspace: {
       async list(request) {

packages/host/apiproxy/tests/native-directory-picker.spec.ts

@@ -1,139 +0,0 @@
-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')
-  })
-})

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

@@ -12,7 +12,11 @@ import {
   sessionModelsValueSchema, sessionPromptRequestSchema, sessionPromptValueSchema,
   sessionSelectModelRequestSchema, sessionSelectModelValueSchema, sessionSummarySchema,
 } from '../src/api/sessions.schema.ts'
-import { hostDescribeRequestSchema, hostDescribeValueSchema } from '../src/api/host.schema.ts'
+import {
+  hostCreateDirectoryRequestSchema, hostCreateDirectoryValueSchema,
+  hostDescribeRequestSchema, hostDescribeValueSchema,
+  hostListDirectoryRequestSchema, hostListDirectoryValueSchema,
+} from '../src/api/host.schema.ts'
 import {
   workspaceCreateRequestSchema, workspaceCreateValueSchema, workspaceIdSchema,
   workspaceDeleteRequestSchema, workspaceDeleteValueSchema,
@@ -204,9 +208,27 @@ describe('sessions domain schemas', () => {
 describe('host domain schemas', () => {
   it('validates describe request/value', () => {
     expect(hostDescribeRequestSchema.parse({})).toEqual({})
-    const value = hostDescribeValueSchema.parse({ version: '1', cwd: '/x', provider: 'p', model: 'm', attachedSessions: 2 })
+    const value = hostDescribeValueSchema.parse({ version: '1', cwd: '/x', provider: 'p', model: 'm', attachedSessions: 2, directoryPicker: 'dialog' })
     expect(value.attachedSessions).toBe(2)
-    expect(hostDescribeValueSchema.parse({ version: '1', cwd: '/x', attachedSessions: 0 }).provider).toBeUndefined()
+    expect(hostDescribeValueSchema.parse({ version: '1', cwd: '/x', attachedSessions: 0, directoryPicker: 'browse' }).provider).toBeUndefined()
+    expect(() => hostDescribeValueSchema.parse({ version: '1', cwd: '/x', attachedSessions: 0, directoryPicker: 'other' })).toThrow()
+  })
+
+  it('validates the browse listing/creation payloads', () => {
+    expect(hostListDirectoryRequestSchema.parse({})).toEqual({})
+    expect(hostListDirectoryRequestSchema.parse({ path: '/x' })).toEqual({ path: '/x' })
+    const listing = hostListDirectoryValueSchema.parse({
+      path: '/home/u/p',
+      home: '/home/u',
+      crumbs: [{ name: '/', path: '/', hidden: false }, { name: 'p', path: '/home/u/p', hidden: false }],
+      entries: [{ name: '.dot', path: '/home/u/p/.dot', hidden: true }],
+    })
+    expect(listing.entries[0]?.hidden).toBe(true)
+    expect(hostCreateDirectoryRequestSchema.parse({ path: '/x', name: 'new' })).toEqual({ path: '/x', name: 'new' })
+    for (const name of ['', ' ', '.', '..', 'a/b', 'a\\b']) {
+      expect(() => hostCreateDirectoryRequestSchema.parse({ path: '/x', name })).toThrow()
+    }
+    expect(hostCreateDirectoryValueSchema.parse({ path: '/x/new' })).toEqual({ path: '/x/new' })
   })
 })
 

packages/host/apiproxy/tsconfig.json

@@ -50,6 +50,9 @@
     {
       "path": "../../workspace/workspace"
     },
+    {
+      "path": "../directory-picker"
+    },
     {
       "path": "../../support/invariants"
     }