fix(plugins): pin every command to its activation runtime

App.tsx

@@ -12,6 +12,7 @@ import { ToastProvider } from './components/ui/toast';
 import { TooltipProvider } from './components/ui/tooltip';
 import { ScriptAutomationRoot } from './components/scripts/ScriptAutomationRoot';
 import { ExternalMcpApprovalsHost } from './components/ai/ExternalMcpApprovalsHost';
+import { PluginHostInteractionHost } from './components/plugins/PluginHostInteractionHost';
 import { PluginAuthenticationHost } from './components/plugins/PluginAuthenticationHost';
 import { MultilinePasteConfirmHost } from './components/terminal/MultilinePasteConfirmDialog';
 import { useExternalMcpGrantPersister } from './components/ai/useExternalMcpGrantPersister';
@@ -86,6 +87,7 @@ function AppWithProviders({ settings, appLock }: { settings: SettingsState; appL
               <ScriptAutomationRoot />
               <ExternalMcpApprovalsHost />
               <PluginAuthenticationHost />
+              <PluginHostInteractionHost />
               <MultilinePasteConfirmHost />
               <VaultPublisher>
                 <SessionPublisher persistSessionRestore={!isPeerSessionWindow}>

application/i18n/locales/en/core.ts

@@ -1246,6 +1246,16 @@ Highlight the focused split pane:
   "settings.plugins.manager.remove": "Uninstall",
   "settings.plugins.manager.removeNote": "Uninstall removes package code and local KV data. User-owned settings, secrets and sync sidecars are retained.",
   "settings.plugins.permissions.statusUnknown": "Status unknown",
+  "plugins.interaction.title": "Plugin request",
+  "plugins.interaction.sharing": "Text you share becomes available to this plugin and its granted capabilities, including network access. Reading does not approve a new network destination.",
+  "plugins.interaction.input": "Input text",
+  "plugins.interaction.filter": "Filter choices",
+  "plugins.interaction.preview": "Preview clipboard",
+  "plugins.interaction.previewNote": "The clipboard is read only after you choose Preview. You can then inspect the text and separately confirm sharing it.",
+  "plugins.interaction.previewAction": "Preview clipboard",
+  "plugins.interaction.share": "Share with plugin",
+  "plugins.interaction.copy": "Copy to clipboard",
+  "plugins.interaction.failed": "This request expired or could not be completed.",
   "settings.plugins.permissions.current": "Matches the current activation",
   "settings.plugins.permissions.inactive": "Inactive for the current activation",
   "settings.plugins.permissions.title": "Saved grants",

application/i18n/locales/es/core.ts

@@ -1246,6 +1246,16 @@ Resalta el panel dividido enfocado:
   "settings.plugins.manager.remove": "Desinstalar",
   "settings.plugins.manager.removeNote": "La desinstalación elimina el código y los datos KV locales. Se conservan los ajustes del usuario, los secretos y los datos auxiliares de sincronización.",
   "settings.plugins.permissions.statusUnknown": "Estado desconocido",
+  "plugins.interaction.title": "Solicitud de complemento",
+  "plugins.interaction.sharing": "El texto compartido estará disponible para este complemento y sus capacidades autorizadas, incluida la red. Leer no autoriza un nuevo destino de red.",
+  "plugins.interaction.input": "Introducir texto",
+  "plugins.interaction.filter": "Filtrar opciones",
+  "plugins.interaction.preview": "Vista previa del portapapeles",
+  "plugins.interaction.previewNote": "El portapapeles se lee al elegir Vista previa. Revise el texto y confirme por separado que desea compartirlo.",
+  "plugins.interaction.previewAction": "Vista previa del portapapeles",
+  "plugins.interaction.share": "Compartir con el complemento",
+  "plugins.interaction.copy": "Copiar al portapapeles",
+  "plugins.interaction.failed": "La solicitud caducó o no pudo completarse.",
   "settings.plugins.permissions.current": "Coincide con la ejecución actual",
   "settings.plugins.permissions.inactive": "No activa para la ejecución actual",
   "settings.plugins.permissions.title": "Autorizaciones guardadas",

application/i18n/locales/ru/core.ts

@@ -1141,6 +1141,16 @@ export const ruCoreMessages: Messages = {
   "settings.plugins.manager.remove": "Удалить",
   "settings.plugins.manager.removeNote": "Удаление очищает код пакета и локальные данные KV. Настройки пользователя, секреты и данные синхронизации сохраняются.",
   "settings.plugins.permissions.statusUnknown": "Состояние неизвестно",
+  "plugins.interaction.title": "Запрос плагина",
+  "plugins.interaction.sharing": "Переданный текст доступен плагину и его разрешённым возможностям, включая сеть. Чтение не разрешает новый сетевой адрес.",
+  "plugins.interaction.input": "Ввести текст",
+  "plugins.interaction.filter": "Фильтр вариантов",
+  "plugins.interaction.preview": "Предпросмотр буфера обмена",
+  "plugins.interaction.previewNote": "Буфер читается только после нажатия предпросмотра. Затем проверьте текст и отдельно подтвердите передачу.",
+  "plugins.interaction.previewAction": "Предпросмотр буфера обмена",
+  "plugins.interaction.share": "Передать плагину",
+  "plugins.interaction.copy": "Копировать в буфер обмена",
+  "plugins.interaction.failed": "Запрос истёк или не выполнен.",
   "settings.plugins.permissions.current": "Соответствует текущему запуску",
   "settings.plugins.permissions.inactive": "Не действует для текущего запуска",
   "settings.plugins.permissions.title": "Сохранённые разрешения",

application/i18n/locales/zh-CN/core.ts

@@ -1161,6 +1161,16 @@ Vaults 标签保持扁平，不使用这块背景。
   "settings.plugins.manager.remove": "卸载",
   "settings.plugins.manager.removeNote": "卸载会移除插件代码和本地 KV 数据，保留用户设置、秘密存储和同步 sidecar。",
   "settings.plugins.permissions.statusUnknown": "状态未知",
+  "plugins.interaction.title": "插件请求",
+  "plugins.interaction.sharing": "分享的文本将交给此插件及其已授权的能力（包括网络访问）。读取文本不代表批准新的网络目标。",
+  "plugins.interaction.input": "输入文本",
+  "plugins.interaction.filter": "筛选选项",
+  "plugins.interaction.preview": "剪贴板预览",
+  "plugins.interaction.previewNote": "仅在点击“预览剪贴板”后读取。检查文本后，还需单独确认才能分享给插件。",
+  "plugins.interaction.previewAction": "预览剪贴板",
+  "plugins.interaction.share": "分享给插件",
+  "plugins.interaction.copy": "复制到剪贴板",
+  "plugins.interaction.failed": "此请求已过期或无法完成。",
   "settings.plugins.permissions.current": "匹配当前运行实例",
   "settings.plugins.permissions.inactive": "对当前运行实例不生效",
   "settings.plugins.permissions.title": "已保存的授权",

application/i18n/locales/zh-TW/core.ts

@@ -1164,6 +1164,16 @@ Vaults 分頁維持扁平，不使用這塊背景。
   "settings.plugins.manager.remove": "卸載",
   "settings.plugins.manager.removeNote": "卸載會移除插件代碼和本地 KV 數據，保留用戶設置、秘密存儲和同步 sidecar。",
   "settings.plugins.permissions.statusUnknown": "狀態不明",
+  "plugins.interaction.title": "外掛請求",
+  "plugins.interaction.sharing": "分享的文字會交給此外掛及其已授權能力（包括網路存取）。讀取文字不代表核准新的網路目的地。",
+  "plugins.interaction.input": "輸入文字",
+  "plugins.interaction.filter": "篩選選項",
+  "plugins.interaction.preview": "剪貼簿預覽",
+  "plugins.interaction.previewNote": "僅在點選「預覽剪貼簿」後讀取。檢查文字後，還需另外確認才能分享給外掛。",
+  "plugins.interaction.previewAction": "預覽剪貼簿",
+  "plugins.interaction.share": "分享給外掛",
+  "plugins.interaction.copy": "複製到剪貼簿",
+  "plugins.interaction.failed": "此請求已過期或無法完成。",
   "settings.plugins.permissions.current": "符合目前執行個體",
   "settings.plugins.permissions.inactive": "對目前執行個體不生效",
   "settings.plugins.permissions.title": "已儲存的授權",

application/state/usePluginHostInteractions.ts

@@ -0,0 +1,53 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+import type { HostInteractionPrompt, HostInteractionResponse } from '@netcatty/plugin-contract';
+import { netcattyBridge } from '../../infrastructure/services/netcattyBridge';
+
+export function usePluginHostInteractions() {
+  const [prompt, setPrompt] = useState<HostInteractionPrompt | null>(null);
+  const [value, setValue] = useState('');
+  const [error, setError] = useState(false);
+  const [busy, setBusy] = useState(false);
+  const current = useRef<HostInteractionPrompt | null>(null);
+  const pending = useRef(false);
+  useEffect(() => {
+    const bridge = netcattyBridge.get();
+    if (!bridge?.onPluginInteraction || !bridge.setPluginInteractionReady) return;
+    const unsubscribe = bridge.onPluginInteraction((event) => {
+      if ('closed' in event) {
+        if (current.current?.requestId !== event.requestId) return;
+        current.current = null; setPrompt(null);
+      } else {
+        current.current = event; setPrompt(event);
+        setValue(event.request.kind === 'input' ? event.request.initialValue ?? '' : '');
+      }
+      pending.current = false; setBusy(false); setError(false);
+    });
+    void bridge.setPluginInteractionReady(true).catch(() => {});
+    return () => {
+      current.current = null;
+      unsubscribe();
+      void bridge.setPluginInteractionReady?.(false).catch(() => {});
+    };
+  }, []);
+  const respond = useCallback(async (action: HostInteractionResponse['action']) => {
+    const active = current.current;
+    if (!active || pending.current) return;
+    pending.current = true; setBusy(true); setError(false);
+    try {
+      const bridge = netcattyBridge.require();
+      if (!bridge.respondPluginInteraction) throw new Error('Host interactions unavailable');
+      const accepted = await bridge.respondPluginInteraction({
+        requestId: active.requestId, actionToken: active.actionToken, action,
+        ...(action === 'submit' && (active.request.kind === 'input' || active.request.kind === 'quickPick') ? { value } : {}),
+      });
+      if (!accepted && current.current?.actionToken === active.actionToken) {
+        current.current = null; setPrompt(null);
+      }
+    } catch {
+      if (current.current?.actionToken === active.actionToken) setError(true);
+    } finally {
+      if (current.current?.actionToken === active.actionToken) { pending.current = false; setBusy(false); }
+    }
+  }, [value]);
+  return { prompt, value, setValue, error, busy, respond };
+}

components/PluginHostInteractionHost.test.tsx

@@ -0,0 +1,91 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { EventEmitter } from 'node:events';
+import { JSDOM } from 'jsdom';
+
+test('host dialog drives choice/input/copy and the two-phase clipboard share using real service action tokens', async () => {
+  const dom = new JSDOM('<!doctype html><html><body><div id="root"></div></body></html>', { pretendToBeVisual: true, url: 'http://localhost' });
+  const previous = new Map<string, PropertyDescriptor | undefined>();
+  const install = (key: string, value: unknown) => {
+    previous.set(key, Object.getOwnPropertyDescriptor(globalThis, key));
+    Object.defineProperty(globalThis, key, { configurable: true, writable: true, value });
+  };
+  for (const key of ['window', 'document', 'navigator', 'HTMLElement', 'HTMLInputElement', 'Element', 'Node', 'NodeFilter', 'MutationObserver', 'CustomEvent', 'Event', 'KeyboardEvent', 'MouseEvent']) {
+    install(key, key === 'window' ? dom.window : dom.window[key as keyof typeof dom.window]);
+  }
+  install('getComputedStyle', dom.window.getComputedStyle.bind(dom.window));
+  install('requestAnimationFrame', dom.window.requestAnimationFrame.bind(dom.window));
+  install('cancelAnimationFrame', dom.window.cancelAnimationFrame.bind(dom.window));
+  install('IS_REACT_ACT_ENVIRONMENT', true);
+  const { default: React, act } = await import('react');
+  const { createRoot } = await import('react-dom/client');
+  const { I18nProvider } = await import('../application/i18n/I18nProvider');
+  const { PluginHostInteractionHost } = await import('./plugins/PluginHostInteractionHost');
+  const { PluginHostInteractionService, assertInteractionRequest } = await import('../electron/plugins/hostInteractionService.cjs');
+  let listener: ((event: unknown) => void) | null = null;
+  let reads = 0;
+  const writes: string[] = [];
+  const audits: unknown[] = [];
+  const sender = Object.assign(new EventEmitter(), { id: 7, isDestroyed: () => false, send(_channel: string, payload: unknown) { listener?.(payload); } });
+  const owner = Object.assign(new EventEmitter(), { webContents: sender, isFocused: () => true, isVisible: () => true, isDestroyed: () => false });
+  const service = new PluginHostInteractionService({
+    getWindow: () => owner, isLocked: () => false,
+    permissionEngine: { onDidRevoke() { return { dispose() {} }; } },
+    database: { recordSecurityAudit(...args: unknown[]) { audits.push(args); } },
+    quotaManager: { chargeBytes() {} },
+    clipboard: { readText() { reads++; return 'synthetic private text'; }, writeText(value: string) { writes.push(value); } },
+  });
+  Object.assign(dom.window, { netcatty: {
+    onPluginInteraction(callback: (event: unknown) => void) { listener = callback; return () => { listener = null; }; },
+    async setPluginInteractionReady(ready: boolean) { return service.setReady(sender, ready); },
+    async respondPluginInteraction(response: unknown) { return service.respond(sender, response); },
+  } });
+  const context = { pluginId: 'com.example.synthetic', pluginVersion: '1.0.0', runtimeId: 'runtime-synthetic', signal: new AbortController().signal, async assertActive() {} };
+  const root = createRoot(document.getElementById('root')!);
+  const settle = () => new Promise((resolve) => setTimeout(resolve, 20));
+  const button = (text: string) => Array.from(document.querySelectorAll<HTMLButtonElement>('button')).find((item) => item.textContent === text)!;
+  const click = async (element: HTMLElement) => { assert.ok(element); await act(async () => { element.click(); await settle(); }); };
+  const begin = async (params: unknown) => {
+    let promise!: Promise<unknown>;
+    await act(async () => { promise = service.request(assertInteractionRequest(params), context); void promise.catch(() => {}); await settle(); });
+    return { promise };
+  };
+  try {
+    await act(async () => root.render(<I18nProvider locale="en"><PluginHostInteractionHost /></I18nProvider>));
+    const choice = await begin({ kind: 'quickPick', title: 'Synthetic choice', items: [{ id: 'compose', label: 'Compose' }] });
+    assert.match(document.querySelector('[role="dialog"]')?.textContent ?? '', /com.example.synthetic/);
+    assert.equal(button('Continue').disabled, true);
+    await click(document.querySelector<HTMLInputElement>('input[type="radio"]')!);
+    await click(button('Continue'));
+    assert.deepEqual(await choice.promise, { cancelled: false, value: 'compose' });
+    await assert.rejects(begin({ kind: 'input', title: 'Invalid hidden newline', initialValue: 'first\nsecond' }), /invalid/);
+    assert.equal(document.querySelector('[role="dialog"]'), null, 'invalid initial text never creates a misleading single-line dialog');
+    const input = await begin({ kind: 'input', title: 'Synthetic input', initialValue: 'synthetic output' });
+    assert.equal(document.querySelector<HTMLInputElement>('input')?.value, 'synthetic output');
+    await click(button('Continue'));
+    assert.deepEqual(await input.promise, { cancelled: false, value: 'synthetic output' });
+    const copy = await begin({ kind: 'clipboard.write', title: 'Copy result', text: 'synthetic output' });
+    assert.deepEqual(writes, []);
+    assert.equal(document.querySelector('textarea')?.value, 'synthetic output');
+    await click(button('Copy to clipboard'));
+    assert.deepEqual(await copy.promise, { cancelled: false, value: true });
+    assert.deepEqual(writes, ['synthetic output']);
+    const share = await begin({ kind: 'clipboard.read', title: 'Share clipboard' });
+    assert.equal(reads, 0);
+    assert.equal(document.querySelector('textarea'), null);
+    await click(button('Preview clipboard'));
+    assert.equal(reads, 1);
+    assert.equal(document.querySelector('textarea')?.value, 'synthetic private text');
+    await click(button('Share with plugin'));
+    assert.deepEqual(await share.promise, { cancelled: false, value: 'synthetic private text' });
+    assert.equal(JSON.stringify(audits).includes('synthetic private text'), false);
+    const cancelled = await begin({ kind: 'clipboard.write', title: 'Cancelled copy', text: 'must not copy' });
+    await click(button('Cancel'));
+    assert.deepEqual(await cancelled.promise, { cancelled: true });
+    assert.deepEqual(writes, ['synthetic output']);
+    assert.equal(service.pending.size, 0);
+  } finally {
+    await act(async () => { root.unmount(); await settle(); }); service.shutdown(); dom.window.close();
+    for (const [key, descriptor] of previous) { if (descriptor) Object.defineProperty(globalThis, key, descriptor); else Reflect.deleteProperty(globalThis, key); }
+  }
+});

components/plugins/PluginHostInteractionHost.tsx

@@ -0,0 +1,54 @@
+import React, { useState } from 'react';
+import { PLUGIN_HOST_INTERACTION_LIMITS } from '@netcatty/plugin-contract';
+import { useI18n } from '../../application/i18n/I18nProvider';
+import { usePluginHostInteractions } from '../../application/state/usePluginHostInteractions';
+import { Button } from '../ui/button';
+import { Input } from '../ui/input';
+import { Dialog, DialogContent, DialogDescription, DialogFooter, DialogHeader, DialogTitle } from '../ui/dialog';
+
+export function PluginHostInteractionHost() {
+  const state = usePluginHostInteractions();
+  if (!state.prompt) return null;
+  return <HostInteractionDialog key={state.prompt.requestId} state={state} prompt={state.prompt} />;
+}
+
+function HostInteractionDialog({ state, prompt }: {
+  state: ReturnType<typeof usePluginHostInteractions>;
+  prompt: NonNullable<ReturnType<typeof usePluginHostInteractions>['prompt']>;
+}) {
+  const { t } = useI18n();
+  const [search, setSearch] = useState('');
+  const request = prompt.request;
+  const previewClipboard = request.kind === 'clipboard.read' && prompt.phase === 'request';
+  const textBytes = new TextEncoder().encode(state.value).length;
+  const canSubmit = request.kind === 'quickPick' ? request.items.some((item) => item.id === state.value) : textBytes <= PLUGIN_HOST_INTERACTION_LIMITS.textBytes;
+  return <Dialog open onOpenChange={(open) => { if (!open) void state.respond('cancel'); }}>
+    <DialogContent className="sm:max-w-[520px]" hideCloseButton>
+      <DialogHeader>
+        <DialogTitle>{t('plugins.interaction.title')}</DialogTitle>
+        <DialogDescription className="break-all">{prompt.pluginId} · {prompt.pluginVersion}</DialogDescription>
+      </DialogHeader>
+      <p className="break-words text-sm font-medium">{request.title}</p>
+      <p className="text-xs text-muted-foreground">{t('plugins.interaction.sharing')}</p>
+      {request.kind === 'input' && <Input aria-label={t('plugins.interaction.input')} value={state.value} maxLength={PLUGIN_HOST_INTERACTION_LIMITS.textBytes} autoComplete="off" autoFocus disabled={state.busy} onChange={(event) => state.setValue(event.target.value)} />}
+      {request.kind === 'quickPick' && <>
+        <Input aria-label={t('plugins.interaction.filter')} value={search} onChange={(event) => setSearch(event.target.value)} autoFocus disabled={state.busy} />
+        <div className="max-h-64 space-y-2 overflow-y-auto" role="radiogroup" aria-label={request.title}>
+          {request.items.filter((item) => `${item.label} ${item.description ?? ''}`.toLocaleLowerCase().includes(search.toLocaleLowerCase())).map((item) => <label key={item.id} className="flex items-start gap-3 rounded-md border p-3">
+            <input type="radio" name="plugin-host-choice" value={item.id} checked={state.value === item.id} disabled={state.busy} onChange={() => state.setValue(item.id)} />
+            <span className="min-w-0 break-words text-sm">{item.label}{item.description && <span className="block text-xs text-muted-foreground">{item.description}</span>}</span>
+          </label>)}
+        </div>
+      </>}
+      {previewClipboard && <p className="text-sm">{t('plugins.interaction.previewNote')}</p>}
+      {(request.kind === 'clipboard.write' || prompt.phase === 'preview') && <textarea aria-label={t('plugins.interaction.preview')} readOnly className="min-h-28 max-h-64 w-full resize-none rounded-md border bg-muted/30 p-3 font-mono text-xs" value={request.kind === 'clipboard.write' ? request.text : prompt.previewText ?? ''} />}
+      {state.error && <p role="alert" className="text-sm text-destructive">{t('plugins.interaction.failed')}</p>}
+      <DialogFooter>
+        <Button variant="outline" disabled={state.busy} onClick={() => void state.respond('cancel')}>{t('common.cancel')}</Button>
+        <Button disabled={state.busy || !canSubmit} onClick={() => void state.respond(previewClipboard ? 'preview' : 'submit')}>
+          {t(previewClipboard ? 'plugins.interaction.previewAction' : request.kind === 'clipboard.read' ? 'plugins.interaction.share' : request.kind === 'clipboard.write' ? 'plugins.interaction.copy' : 'common.continue')}
+        </Button>
+      </DialogFooter>
+    </DialogContent>
+  </Dialog>;
+}

docs/plugin-platform/capability-coverage.md

@@ -11,13 +11,13 @@ mean complete. Existing APIs remain available.
 
 | Subsystem | Working API at baseline | Enumeration or missing adapter | Accepted bounded entry | Data and action risk | Authorization resource | Revocation, audit, quota | Verification and disposition |
 | --- | --- | --- | --- | --- | --- | --- | --- |
-| Authorization management | Engine `listGrants`, `revokeAll`, database audit | Manager shows declarations only | Host-only grant list, bounded audit summary, disable and revoke | Paths, session IDs, grant metadata are sensitive | Exact plugin ID, trusted app sender | Serialized manager mutation, disable before revoke, runtime teardown, retained audit | Batch 1 implemented: host/manager/UI tests. Native acceptance pending. No plugin RPC for managing grants |
-| Network and credential leases | `network.request`, `credentials.createLease`, single-use host redemption | SDK request omits lease and authorization fields | Canonical request types matching broker | Network mutation and credentials | Exact origin plus secret reference and operation | Existing timeout, redirects, byte quotas, runtime checks, lease TTL | Batch 1 implemented: canonical schema and SDK, synthetic fixture and lease tests, feature negotiation. Native acceptance pending. No plaintext secret API |
+| Authorization management | Engine `listGrants`, `revokeAll`, database audit | Manager shows declarations only | Host-only grant list, bounded audit summary, disable and revoke | Paths, session IDs, grant metadata are sensitive | Exact plugin ID, trusted app sender | Serialized manager mutation, disable before revoke, runtime teardown, retained audit | Batch 1 limited acceptance complete on ff3734d: independent review fixes, host/manager/UI tests, exact test/packaging CI, parent native own-views Application grant/revoke/disable/runtime-stop check. Visible view was manually closed beforehand. No plugin RPC for managing grants |
+| Network and credential leases | `network.request`, `credentials.createLease`, single-use host redemption | SDK request omits lease and authorization fields | Canonical request types matching broker | Network mutation and credentials | Exact origin plus secret reference and operation | Existing timeout, redirects, byte quotas, runtime checks, lease TTL | Batch 1 contract/SDK consistency complete: canonical types, synthetic fixture/lease tests, feature discovery and exact CI. No live network or credential acceptance claimed. No plaintext secret API |
 | Commands, menus, toolbar, status bar, views | `commands.execute`, settings, context keys, view state and messages, UI contributions | No editor or SFTP menu slots | Existing contribution system | Plugin text and arguments may be sensitive | Namespaced contributions and permissions | Existing lifecycle, rate and message limits | Existing tests. New context menu slots planned with bounded context DTOs |
 | Terminal providers | Decorations, links, completion, snapshots through provider requests | Session change delivery follows prior provider request and non-once grant | Preserve providers. Standalone selected-session watch planned | Hostnames, session state, endpoint identity | Host-selected session, runtime identity | Session-close and revoke cleanup, bounded event rate | Existing provider tests. Ordinary views cannot independently subscribe today |
 | Current context and host picker | Host context keys are boolean state | `vault.metadata` enumeration is not generic SDK | Selected host/session DTO from an explicit whitelist | Labels and endpoint metadata are sensitive | Host-owned user-action context, selected host/session | TTL, runtime and session invalidation, redacted audit | Planned. Never reuse agent `sanitizeHostForAgent` as plugin DTO |
 | Terminal selection and input draft | Provider-supplied snapshots, completion suggestions | No explicit selection-share or draft API | User shares selection, plugin proposes a visible editable draft | Terminal plaintext, accidental execution | Host action token plus exact live session/endpoint | Single-use token, size cap, no plaintext audit, active identity before commit | Planned. Reject Enter/control characters for draft insertion. No full history or direct shell |
-| Native interactions and clipboard | Native permission dialogs | Clipboard enum only. No quick-pick/input/progress/toast SDK | Host-owned prompts, explicit copy/paste with preview | Clipboard and input may contain secrets, prompt spam | Host action context plus clipboard direction | Cancellation, request count and byte caps, runtime cleanup | Planned. No background reads or trusted plugin `userGesture` boolean |
+| Native interactions and clipboard | Native permission dialogs; new browser SDK host choice/input and explicit copy/share workflow | Progress/toast remain unimplemented | Host-owned prompts, two-phase clipboard snapshot/share, exact copy preview | Clipboard and input may contain secrets; UI discloses granted network capability; prompt spam | `ui.interact`, clipboard direction, host-signed window/runtime/version/phase/TTL action | Admission before permission prompt, byte/rate/concurrency limits, lock/blur/close/revoke cleanup, active guard, content-free audit | [Host interaction slice](./host-interactions.md) implemented and synthetic-tested; native acceptance/review/CI pending. Progress/toast still planned. No background reads or trusted plugin `userGesture` boolean |
 | Local filesystem | Read file, stat, overwrite existing regular file | Directory listing lacks same-handle native adapter | Keep current boundary, evaluate file picker handles | Arbitrary local file content and writes | Canonical exact path or selected file handle | Inode checks, no symlink alias, bounded bytes, active runtime | Existing filesystem tests. Directory enumeration and new arbitrary-path creation deferred until portable safe native adapter exists |
 | SFTP and remote files | No generic plugin API | `sftp.read` and `sftp.write` enumerated only | Host-selected session/path/mode/TTL handles, read and explicit save/upload | Remote secrets and destructive overwrite | Live endpoint identity, exact path, read/write split | Cancel streams, byte quota, overwrite confirmation, close/revoke cleanup | Batch 2 planned. Never forward arbitrary MCP catalog or session ID alone |
 | Editor and Notes | No plugin document API | No versioned snapshot or edit preview | Explicit snapshot and versioned proposed edit | Document secrets, lost updates, executable files | Selected document plus revision and action token | Version conflict check, preview, bounded bytes, revocation | Planned evaluation after shared action context. No unattended edits |
@@ -27,21 +27,25 @@ mean complete. Existing APIs remain available.
 | Vault and keychain | Credential references and import preview/commit | Metadata/write enums do not grant a generic Vault SDK | Only user-selected whitelist DTOs and drafts | Notes, environmentVariables, startupCommand, keys and credentials | Selected object plus field/direction | Explicit preview, identity checks, redacted audit | Full Vault export and secret reads deferred indefinitely. No agent field-exclusion DTO reuse |
 | System manager and Docker | No plugin system API | Agent/MCP adapters are separate authority | Typed read-only summaries excluding args/env/inspect | Process command lines and Docker inspect can expose secrets | Selected live session and summary kind | Bounded result, endpoint identity, cancellation | Planned evaluation. Arbitrary process/inspect forwarding deferred |
 | Port forwarding | No generic plugin API | Existing agent start is write-sensitive | Selected rule status and open host form | Rule endpoints and local exposure | Selected rule plus host action | Bounded DTO, session close and revoke | Planned evaluation. Direct start deferred until binding/listener approval design |
-| Themes, settings, appearance, i18n | Contributions, scoped setting API, environment updates | No arbitrary application settings write | Existing namespaced contributions. Candidate: declarative global ThemePack using the 19 semantic tokens in `uiThemes.ts`, with preview/apply/reset and uninstall fallback | Settings can contain sensitive plugin values. A theme must preserve contrast and security UI | Plugin namespace, declared scope | Existing persistence and lifecycle, explicit sync flag | Existing tests. ThemePack design pending parent review of allowed tokens, accessibility and fallback. No arbitrary host DOM/CSS, remote CSS/fonts or security UI hiding. Arbitrary host settings mutation deferred |
+| Themes, settings, appearance, i18n | Terminal theme/background Providers, isolated view CSS, scoped settings and environment updates | No host global theme contribution. Personal customCSS is not plugin authority | Accepted ThemePack stage: static palette registry, selector, local preview, revision-safe apply/cancel/reset, terminal linkage | Unreadable palettes and misleading security UI. Nineteen UiThemeTokens fields are not independent: accent derives primary/ring/foregrounds | User explicitly selects a theme; static contribution enablement separate from code permissions | Immutable version/hash, bounded JSON, contrast/security-surface gates, preview owner/revision and safe fallback | Planned independent implementation after current controlled workflow/navigation. No arbitrary DOM/CSS, remote assets, layout replacement or security UI customization |
 | Transfer center | Host transfer queue exists, no plugin entry | No ownership-bound task API | Observe and cancel only plugin-created tasks | Paths and host endpoints reveal user data. Cancel may leave partial files | Own transfer handle plus source/destination authority | Shared backpressure, cancel/close cleanup, honest partial status | Planned with batch 2. Do not broadcast or cancel other tasks |
 | AI, MCP, automation | Host agent catalog and harness exist separately | No generic plugin AI or tool forwarding | Selection-to-proposal workflow through the same controlled primitives | Content disclosure, account authority and model cost | Explicit content sharing plus service origin/budget | No inherited history, tools, account, or hidden cron | Controlled workflow planned. Generic host AI and visible schedules deferred to distinct product decision |
 | Known hosts, app lock and global security | Host security management UI | No plugin management API | Future allowlisted security-page navigation | Host-key trust, unlock, keys and security policy affect all sessions | Host navigation action only | No mutation or sensitive DTO | Security policy mutation, private-key reads, auto-trust and unlocking deferred indefinitely |
 | Plugin blob/cache | Local KV exists | No exclusive blob cache | Evaluate bounded plugin-owned cache when a real workflow needs it | Disk growth and lifecycle ambiguity | Plugin namespace, no arbitrary path | Size quota, eviction and uninstall policy required | Deferred until a concrete larger-than-KV workflow establishes value and retention policy |
+| Vault and terminal navigation | `tab` mounts a sandbox page through TopTabs/QuickSwitcher; aside/panel are overlays | No Vault subpage registry or terminal side-panel plugin tool. `settings` is a detail entry, not a new settings category | Accepted independent slice: host-owned namespaced Vault pages in an Extensions group, mounted in the Vault content area through existing ViewHost; then terminal pane/split pages for the selected session | Navigation cannot disclose session contents or replace built-in/security navigation | Declared page contribution plus host selection. Content reads have independent permissions | Host order/when/focus, cancellation of late open, view cleanup on hide/update/disable/uninstall, safe invalid-link fallback | Planned after host interaction/selected-context workflow. A button that merely opens a top tab does not satisfy Vault-page acceptance. No arbitrary router/DOM API |
 | Distribution and runtimes | Browser-only public catalog, immutable packages, advanced developer gate | Signing/trust and release remain separate phase | Retain existing boundary | Package execution and publisher trust | Pinned catalog selection, hash, engine/features | Existing install transaction, quarantine and cleanup | No merge/release. Do not extend to arbitrary Node, IPC, shell, or global capabilities |
 
 ## Delivery order and stopping rule
 
 1. Batch 1: actual authorization management plus network contract consistency.
    Keep the existing manager layout. Add one independent permission panel.
-2. Batch 1b: host action context, native interactions, selected context and terminal
+2. Batch 1b: the host text interaction slice, then selected context and terminal
    sharing/drafts. A plugin-supplied gesture is never authority.
-3. Batch 2: SFTP selected-file handles and explicit transfer destinations.
-4. Reassess editor, Notes, snippets, menus, system summaries, and port forwarding
+3. A separate navigation slice mounts actual Vault extension pages, then terminal
+   sidebar panes, reusing the isolated ViewHost and keeping content permissions separate.
+4. Deliver the declarative ThemePack stage with security appearance and contrast gates.
+5. Batch 2: SFTP selected-file handles and explicit transfer destinations.
+6. Reassess editor, Notes, snippets, menus, system summaries, and port forwarding
    using the tested host-action and resource primitives.
 
 Stop only when every row is implemented and tested, reasonably deferred with a

docs/plugin-platform/host-interactions.md

@@ -0,0 +1,130 @@
+# Host text interactions
+
+Status: internal preview. This layer builds on the grant management in Draft
+#3955. It adds `host.interactions` feature discovery, a generated request/result
+contract, and an ordinary browser SDK workflow. Native acceptance remains a
+separate parent-owned gate.
+
+## SDK and authorization
+
+| SDK call | Permission | Result |
+| --- | --- | --- |
+| `ui.quickPick(title, items)` | `ui.interact` | Approved item ID or `undefined` on cancel |
+| `ui.input(title, initialValue?)` | `ui.interact` | Approved single-line text or `undefined` on cancel |
+| `clipboard.readText(title)` | `clipboard.read` | Explicitly shared snapshot or `undefined` on cancel |
+| `clipboard.writeText(text, title)` | `clipboard.write` | `true` after copy, `false` on cancel |
+
+`ui.input` rejects CR and LF in initial values before any dialog is displayed,
+and rejects line breaks on submission. It does not silently remove hidden
+newlines. The displayed single-line value is the value submitted to the plugin.
+Clipboard text continues to support multiple lines.
+
+All calls use the canonical `ui.interact` RPC. No host DOM, native object,
+router, general command ID, or arbitrary IPC channel enters the SDK. Existing
+API versions remain offered. A plugin requiring the new workflow declares
+`features.required: ["host.interactions"]`; old hosts reject unsupported
+required features. Old plugins keep their existing APIs and permissions.
+
+Clipboard prompts restrict new permission decisions to once. Required or
+previously saved grants never skip the host action confirmation. Input and
+choice dialogs need their own declaration; a `views` or `menus` declaration is
+not permission to open them. Direction-specific clipboard permissions remain
+separate. The normal sample uses no network, host/session, filesystem, secret,
+Node, or shell capability.
+
+## User action and text sharing
+
+The host always displays plugin ID/version and a fixed source heading. Titles,
+choices, and text render as plain text. No plugin-supplied `userGesture` flag is
+accepted. The host creates an HMAC action token bound to request ID, runtime,
+plugin version, owner window, action kind, phase, nonce, and expiry. It sends
+that token only to the trusted host renderer. A response must come from the
+same WebContents and present the current token. Tokens are consumed before the
+first asynchronous action guard, so old-phase and duplicate responses cannot
+commit an action.
+
+Clipboard reading has two steps. **Preview clipboard** authorizes a host read
+into a bounded in-memory snapshot. The plugin receives nothing yet. **Share
+with plugin** sends exactly that snapshot after another active-identity check.
+Changes to the system clipboard after preview do not replace it. Cancel, lock,
+window loss, or revoke discards the snapshot. Copy shows the exact replacement
+text and requires its own confirmation before a native write.
+
+Shared text can be sensitive. The host explains that it becomes available to
+the plugin and its granted capabilities, including network access. Reading
+text does not approve a new network destination. This UI does not claim to
+prevent a plugin from transmitting derived text through an already granted
+capability. The example avoids network permission entirely.
+
+## Availability, limits, and cleanup
+
+The first slice supports the focused, visible, unlocked main window only.
+The host renderer registers readiness before any prompt can be presented.
+Other or unready windows return unavailable instead of inheriting an owner's
+authority. One interaction occupies an owner window at a time; there is no
+hidden prompt queue.
+
+`HostInteractionLimits` is the shared canonical source for 4,096 UTF-8 text
+bytes, 100 choices, 64 KiB serialized requests, one pending request per runtime,
+eight total, ten attempts per minute per runtime, and a 60-second lifetime.
+The current main-window-only adapter is narrower than the total pending bound.
+Admission runs before the permission prompt. The generic capability quotas and
+byte windows still apply. Text exceeding its cap is rejected without silent
+truncation. RPC uses the same generated deadline.
+
+After a native permission decision, an originally foreground request can wait
+at most one second for the same owner to regain focus. The host never focuses
+the window itself, presents content in the background, or postpones admission
+for an originally background request. Hide, lock, revoke, runtime stop, owner
+replacement and reload invalidate this admission, even during the permission
+dialog. Runtime activity and foreground state are checked again after waiting.
+
+Input cancellation, timeout, disable/update/crash/revoke, owner blur/hide/close,
+main-document reload, renderer exit, and app lock invalidate pending tokens.
+Same-document or subframe navigation does not permanently unregister a live
+host UI. Runtime teardown clears rate accounting. The broker checks runtime
+activity, owner readiness/focus, and app lock again immediately before native
+read/write or disclosure. A revoked operation cannot resume from a late reply.
+
+Commands normally retain the existing 30-second RPC deadline. A command that
+declares `interactive: true` must require `commands.interactive`; the host gives
+only that command a fixed 180-second total budget. This is not a global timeout
+increase or a UI/clipboard permission. Each individual host interaction still
+has its own 60-second deadline, including permission approval time.
+
+When an outer command fails, times out or is cancelled, the host cancels pending
+interactions and pre-prompt admissions for its captured runtime. On successful
+completion it closes orphan interactions once the last concurrent command ends.
+This cleanup does not reset rate/byte quotas and cannot affect a replacement
+runtime. A failure conservatively closes that runtime's single shared pending
+dialog even if another command is active. Late action tokens cannot commit a
+clipboard effect. Cancellation does not forcibly terminate arbitrary plugin
+JavaScript; ignored errors remain subject to permission, focus, rate and runtime
+limits. Do not start independent interactive workflows concurrently.
+
+Audit records contain only fixed event/action/kind fields. They contain no
+prompt, choices, user text, clipboard bytes, action tokens, or hashes derived
+from those values. A failed consent-audit write prevents the native action;
+no successful operation is reported for that failure.
+
+## Verification and native acceptance
+
+The [browser fixture](../../examples/plugins/host-interactions/README.md)
+exercises choice, input, copy, and clipboard transformation without a plugin
+view. Tests cover the actual runtime/SDK RPC path through permission middleware,
+actual host React dialog events against service-signed actions, denial, cancel,
+quota before prompt, overlong text, duplicate/forged actions, wrong owners,
+stale runtime, revoke during an asynchronous guard, audit failure, deadline,
+lock, blur, document navigation, and renderer teardown.
+
+Parent native acceptance uses a separately approved temporary example-plugin
+session and synthetic clipboard text. It needs no real hosts, credentials,
+network destination, shell, or persistent grant. Check both complete workflows,
+cancel before reading, cancel after preview, cancel copy, and disable/revoke
+with a pending dialog. Record the exact SHA and restore the test clipboard.
+Unit tests are not evidence of native Electron acceptance.
+
+Progress/toast, selected context and terminal sharing/drafts remain later slices.
+Navigation uses the existing sandbox ViewHost and adds no content permission.
+ThemePack and SFTP remain separate stages. This layer alone does not finish the
+capability coverage matrix.

domain/pluginPermissionDescriptions.cjs

@@ -9,6 +9,7 @@ const PERMISSION_DESCRIPTIONS = {
   "settings.write": [false, "Change plugin settings", "Update this plugin's preferences.", "修改插件设置", "修改此插件自己的设置。"],
   commands: [false, "Plugin commands", "Register and run this plugin's own commands.", "插件命令", "注册和执行此插件自己的命令。"],
   menus: [false, "Menu entries", "Add this plugin's actions to host menus.", "菜单入口", "将此插件的操作加入应用菜单。"],
+  "ui.interact": [false, "Host prompts", "Ask the host to show bounded input and choice dialogs.", "宿主交互", "请求宿主显示有界的输入和选择对话框。"],
   views: [false, "Plugin panels", "Display plugin-owned panels inside the app.", "插件面板", "在应用中显示插件自己的面板。"],
   "clipboard.read": [true, "Read clipboard", "Read copied text, which may contain passwords or other sensitive data.", "读取剪贴板", "读取复制的文本，其中可能包含密码或其他敏感数据。"],
   "clipboard.write": [true, "Write clipboard", "Replace clipboard content that you may paste elsewhere.", "写入剪贴板", "替换剪贴板内容，可能影响你随后粘贴的数据。"],

electron/main/registerBridges.cjs

@@ -165,6 +165,9 @@ function createBridgeRegistrar(context) {
           app,
           electron: electronModule,
           safeStorage,
+          getInteractionWindow: () => win,
+          isAppLocked: () => getAppLockController?.()?.getRuntimeState?.()?.locked !== false,
+          subscribeAppLock: (listener) => getAppLockController?.()?.subscribe?.(listener),
           requestPermissionDecision: createNativePermissionDecisionProvider({
             getLocale: () => getWindowManager().getCurrentLanguage?.() ?? "en",
             dialog: electronModule.dialog,
@@ -217,6 +220,7 @@ function createBridgeRegistrar(context) {
     });
     registerPluginBridge(ipcMain, {
       manager: pluginHostService?.manager,
+      interactionService: pluginHostService?.interactionService,
       permissionEngine: pluginHostService?.permissionEngine,
       runtimeSupervisor: pluginHostService?.runtimeSupervisor,
       database: pluginHostService?.database,

electron/plugins/contributionService.cjs

@@ -6,6 +6,7 @@ const { assertPluginContextKey, evaluateContextKeyExpression } = require("./cont
 const { assertPluginJsonValue } = require("./jsonBoundary.cjs");
 const { compileRestrictedJsonSchema } = require("./restrictedJsonSchema.cjs");
 const { PluginRpcError, RPC_ERRORS } = require("./rpcRouter.cjs");
+const { InteractiveCommandFeature, InteractiveCommandLimits } = require("./generated/plugin-contract.schema.json").$defs;
 
 const MAX_SETTING_BYTES = 128 * 1024;
 const MAX_PATTERN_LENGTH = 512;
@@ -149,6 +150,8 @@ class PluginContributionService {
   constructor(options) {
     this.database = options.database;
     this.runtimeSupervisor = options.runtimeSupervisor;
+    this.onCommandFinished = options.onCommandFinished;
+    this.activeCommandCalls = new Map();
     this.secretStore = options.secretStore;
     this.getLocale = options.getLocale ?? (() => "en");
     this.contextKeys = new Map();
@@ -336,12 +339,31 @@ class PluginContributionService {
       throw new PluginRpcError(RPC_ERRORS.failedPrecondition, `Plugin command is disabled: ${commandId}`);
     }
     assertJsonValue(args ?? null, "command arguments");
-    await this.#ensureActivated(plugin, `onCommand:${commandId}`);
-    return this.runtimeSupervisor.request(plugin.id, "plugin.command.execute", {
-      command: commandId,
-      ...(args === undefined ? {} : { args }),
-      invocation: freezeJson({ source: invocation.source ?? "host", context: invocation.context ?? {} }),
-    });
+    if (contribution.interactive && !plugin.manifest.features?.required?.includes(InteractiveCommandFeature.const)) {
+      throw new PluginRpcError(RPC_ERRORS.failedPrecondition, "Interactive command feature is required");
+    }
+    const identity = await this.#ensureActivated(plugin, `onCommand:${commandId}`);
+    const runtimeId = identity?.runtimeId;
+    if (runtimeId) this.activeCommandCalls.set(runtimeId, (this.activeCommandCalls.get(runtimeId) ?? 0) + 1);
+    let failed = true;
+    try {
+      const result = await this.runtimeSupervisor.request(plugin.id, "plugin.command.execute", {
+        command: commandId,
+        ...(args === undefined ? {} : { args }),
+        invocation: freezeJson({ source: invocation.source ?? "host", context: invocation.context ?? {} }),
+      }, { expectedIdentity: identity, ...(contribution.interactive ? { timeoutMs: InteractiveCommandLimits.const.timeoutMs } : {}) });
+      failed = false;
+      return result;
+    } finally {
+      if (runtimeId) {
+        const remaining = Math.max(0, (this.activeCommandCalls.get(runtimeId) ?? 1) - 1);
+        if (remaining) this.activeCommandCalls.set(runtimeId, remaining);
+        else this.activeCommandCalls.delete(runtimeId);
+        // A failed command must not leave a live native consent prompt. On
+        // success wait for other concurrent commands before closing orphans.
+        if (failed || remaining === 0) this.onCommandFinished?.(runtimeId);
+      }
+    }
   }
 
   async activateView(viewId, params = {}) {

electron/plugins/contributionService.test.cjs

@@ -87,6 +87,7 @@ function setup(context, pluginManifest, options = {}) {
     runtimeSupervisor,
     secretStore,
     getLocale: () => "zh-CN",
+    onCommandFinished: options.onCommandFinished,
   });
   return { calls, database, secretStore, service, secrets };
 }
@@ -100,6 +101,48 @@ test("plugin contribution values enforce the exact JSON value boundary", () => {
   }
 });
 
+test("only explicitly declared interactive commands receive the fixed budget and command completion is runtime-bound", async (t) => {
+  const pluginManifest = manifest();
+  delete pluginManifest.contributes.commands[0].enablement;
+  pluginManifest.features = { required: ["commands.interactive"] };
+  pluginManifest.contributes.commands.push({ id: `${pluginManifest.id}.interactive`, title: "Interactive", interactive: true });
+  const optionsSeen = [], finished = [];
+  const runtimeId = "runtime-budget";
+  const { service } = setup(t, pluginManifest, {
+    onCommandFinished: (id) => finished.push(id),
+    runtimeSupervisor: {
+      async start() { return { runtimeId, pluginVersion: pluginManifest.version }; },
+      async request(_id, _method, _params, options) { optionsSeen.push(options); return null; },
+    },
+  });
+  await service.executeCommand(`${pluginManifest.id}.hello`);
+  await service.executeCommand(`${pluginManifest.id}.interactive`);
+  assert.equal(Object.hasOwn(optionsSeen[0], "timeoutMs"), false, "ordinary commands retain the existing router deadline");
+  assert.equal(optionsSeen[0].expectedIdentity.runtimeId, runtimeId);
+  assert.equal(optionsSeen[1].timeoutMs, 180_000);
+  assert.equal(optionsSeen[1].expectedIdentity.runtimeId, runtimeId);
+  assert.deepEqual(finished, [runtimeId, runtimeId]);
+  assert.equal(service.activeCommandCalls.size, 0);
+});
+
+test("concurrent successful commands retain the runtime interaction until the last ends, while a failed command cancels it", async (t) => {
+  const pluginManifest = manifest(); delete pluginManifest.contributes.commands[0].enablement;
+  const pending = [], finished = [];
+  const { service } = setup(t, pluginManifest, { onCommandFinished: (id) => finished.push(id),
+    runtimeSupervisor: { async start() { return { runtimeId: "runtime-concurrent" }; },
+      request() { return new Promise((resolve, reject) => pending.push({ resolve, reject })); } },
+  });
+  const first = service.executeCommand(`${pluginManifest.id}.hello`);
+  const second = service.executeCommand(`${pluginManifest.id}.hello`);
+  await new Promise((resolve) => setImmediate(resolve));
+  pending[0].resolve(null); await first;
+  assert.deepEqual(finished, []);
+  pending[1].reject(new Error("synthetic timeout"));
+  await assert.rejects(second, /synthetic timeout/);
+  assert.deepEqual(finished, ["runtime-concurrent"]);
+  assert.equal(service.activeCommandCalls.size, 0);
+});
+
 test("only onStartupFinished plugins activate during contribution initialization", async (context) => {
   const pluginManifest = manifest("com.example.startup", ["onStartupFinished"]);
   const { calls, service } = setup(context, pluginManifest);

electron/plugins/generated/plugin-contract.schema.json

@@ -231,6 +231,315 @@
       },
       "additionalProperties": false
     },
+    "HostInteractionLimits": {
+      "const": {
+        "textBytes": 4096,
+        "requestBytes": 65536,
+        "items": 100,
+        "pendingPerRuntime": 1,
+        "pendingTotal": 8,
+        "requestsPerMinute": 10,
+        "timeoutMs": 60000
+      }
+    },
+    "HostInteractionFeature": {
+      "const": "host.interactions"
+    },
+    "InteractiveCommandFeature": {
+      "const": "commands.interactive"
+    },
+    "InteractiveCommandLimits": {
+      "const": {
+        "timeoutMs": 180000
+      }
+    },
+    "HostQuickPickItem": {
+      "type": "object",
+      "required": [
+        "id",
+        "label"
+      ],
+      "properties": {
+        "id": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128
+        },
+        "label": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 512
+        },
+        "description": {
+          "type": "string",
+          "maxLength": 512
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostQuickPickRequest": {
+      "type": "object",
+      "required": [
+        "kind",
+        "title",
+        "items"
+      ],
+      "properties": {
+        "kind": {
+          "const": "quickPick"
+        },
+        "title": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128,
+          "pattern": "^[^\\u0000-\\u001f\\u007f]*$"
+        },
+        "items": {
+          "type": "array",
+          "minItems": 1,
+          "maxItems": 100,
+          "items": {
+            "$ref": "#/$defs/HostQuickPickItem"
+          }
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostSingleLineInputText": {
+      "description": "Single-line host input. CR and LF are rejected before display and on submission; clipboard text remains multiline.",
+      "type": "string",
+      "maxLength": 4096,
+      "pattern": "^[^\\u0000\\r\\n]*$"
+    },
+    "HostInputRequest": {
+      "type": "object",
+      "required": [
+        "kind",
+        "title"
+      ],
+      "properties": {
+        "kind": {
+          "const": "input"
+        },
+        "title": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128,
+          "pattern": "^[^\\u0000-\\u001f\\u007f]*$"
+        },
+        "initialValue": {
+          "$ref": "#/$defs/HostSingleLineInputText"
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostClipboardReadRequest": {
+      "type": "object",
+      "required": [
+        "kind",
+        "title"
+      ],
+      "properties": {
+        "kind": {
+          "const": "clipboard.read"
+        },
+        "title": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128,
+          "pattern": "^[^\\u0000-\\u001f\\u007f]*$"
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostClipboardWriteRequest": {
+      "type": "object",
+      "required": [
+        "kind",
+        "title",
+        "text"
+      ],
+      "properties": {
+        "kind": {
+          "const": "clipboard.write"
+        },
+        "title": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128,
+          "pattern": "^[^\\u0000-\\u001f\\u007f]*$"
+        },
+        "text": {
+          "type": "string",
+          "maxLength": 4096,
+          "pattern": "^[^\\u0000]*$"
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostInteractionRequest": {
+      "oneOf": [
+        {
+          "$ref": "#/$defs/HostQuickPickRequest"
+        },
+        {
+          "$ref": "#/$defs/HostInputRequest"
+        },
+        {
+          "$ref": "#/$defs/HostClipboardReadRequest"
+        },
+        {
+          "$ref": "#/$defs/HostClipboardWriteRequest"
+        }
+      ]
+    },
+    "HostInteractionResult": {
+      "oneOf": [
+        {
+          "type": "object",
+          "required": [
+            "cancelled"
+          ],
+          "properties": {
+            "cancelled": {
+              "const": true
+            }
+          },
+          "additionalProperties": false
+        },
+        {
+          "type": "object",
+          "required": [
+            "cancelled",
+            "value"
+          ],
+          "properties": {
+            "cancelled": {
+              "const": false
+            },
+            "value": {
+              "oneOf": [
+                {
+                  "type": "string",
+                  "maxLength": 4096,
+                  "pattern": "^[^\\u0000]*$"
+                },
+                {
+                  "const": true
+                }
+              ]
+            }
+          },
+          "additionalProperties": false
+        }
+      ]
+    },
+    "HostInteractionResponse": {
+      "type": "object",
+      "required": [
+        "requestId",
+        "actionToken",
+        "action"
+      ],
+      "properties": {
+        "requestId": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128
+        },
+        "actionToken": {
+          "type": "string",
+          "minLength": 32,
+          "maxLength": 256
+        },
+        "action": {
+          "enum": [
+            "cancel",
+            "preview",
+            "submit"
+          ]
+        },
+        "value": {
+          "type": "string",
+          "maxLength": 4096,
+          "pattern": "^[^\\u0000]*$"
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostInteractionClosed": {
+      "type": "object",
+      "required": [
+        "requestId",
+        "closed"
+      ],
+      "properties": {
+        "requestId": {
+          "type": "string",
+          "maxLength": 128
+        },
+        "closed": {
+          "const": true
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostInteractionEvent": {
+      "oneOf": [
+        {
+          "$ref": "#/$defs/HostInteractionPrompt"
+        },
+        {
+          "$ref": "#/$defs/HostInteractionClosed"
+        }
+      ]
+    },
+    "HostInteractionPrompt": {
+      "type": "object",
+      "required": [
+        "requestId",
+        "actionToken",
+        "pluginId",
+        "pluginVersion",
+        "expiresAt",
+        "phase",
+        "request"
+      ],
+      "properties": {
+        "requestId": {
+          "type": "string",
+          "maxLength": 128
+        },
+        "actionToken": {
+          "type": "string",
+          "maxLength": 256
+        },
+        "pluginId": {
+          "$ref": "#/$defs/PluginId"
+        },
+        "pluginVersion": {
+          "$ref": "#/$defs/SemanticVersion"
+        },
+        "expiresAt": {
+          "$ref": "#/$defs/SafePositiveInteger"
+        },
+        "phase": {
+          "enum": [
+            "request",
+            "preview"
+          ]
+        },
+        "request": {
+          "$ref": "#/$defs/HostInteractionRequest"
+        },
+        "previewText": {
+          "type": "string",
+          "maxLength": 4096,
+          "pattern": "^[^\\u0000]*$"
+        }
+      },
+      "additionalProperties": false
+    },
     "NetworkCredentialLeaseFeature": {
       "const": "network.credential-lease"
     },
@@ -398,6 +707,7 @@
         "commands",
         "menus",
         "views",
+        "ui.interact",
         "clipboard.read",
         "clipboard.write",
         "terminal.metadata",
@@ -435,6 +745,7 @@
         "commands",
         "menus",
         "views",
+        "ui.interact",
         "clipboard.read",
         "clipboard.write",
         "terminal.metadata",
@@ -871,6 +1182,11 @@
         },
         "enablement": {
           "$ref": "#/$defs/ContextKeyExpression"
+        },
+        "interactive": {
+          "type": "boolean",
+          "default": false,
+          "description": "Require commands.interactive for this command's fixed bounded host interaction budget. Does not grant UI or clipboard permissions."
         }
       },
       "additionalProperties": false

electron/plugins/hostInteractionExample.test.cjs

@@ -0,0 +1,117 @@
+"use strict";
+const assert = require("node:assert/strict");
+const { readFile } = require("node:fs/promises");
+const { EventEmitter } = require("node:events");
+const { pathToFileURL } = require("node:url");
+const test = require("node:test");
+const { MessageChannel } = require("node:worker_threads");
+const { PluginRpcRouter } = require("./rpcRouter.cjs");
+const { PluginHostRpcRegistry } = require("./hostRpcRegistry.cjs");
+const { PluginPermissionEngine } = require("./permissionEngine.cjs");
+const { PluginHostInteractionService } = require("./hostInteractionService.cjs");
+const { PluginContributionService } = require("./contributionService.cjs");
+
+for (const source of ["compose", "share"]) test(`normal browser example completes the ${source} text workflow through permission middleware`, async () => {
+  const { startPluginRuntime } = await import("./runtime/runtimePeer.mjs");
+  const plugin = await import("../../examples/plugins/host-interactions/browser.js");
+  const manifest = JSON.parse(await readFile(new URL("../../examples/plugins/host-interactions/netcatty.plugin.json", pathToFileURL(__filename)), "utf8"));
+  const audit = [], copied = [], requests = [];
+  let reads = 0, active = true;
+  const database = { listPermissionGrants: () => [], recordSecurityAudit(...args) { audit.push(args); } };
+  const permissionEngine = new PluginPermissionEngine({ database,
+    requestDecision: async (request) => { requests.push(request.permission); return { requestId: request.requestId, decision: "allow", scope: "once" }; },
+  });
+  let service;
+  const sender = Object.assign(new EventEmitter(), { id: 7, isDestroyed: () => false,
+    send(_channel, message) {
+      if (message.closed) return;
+      queueMicrotask(() => {
+        const action = message.request.kind === "clipboard.read" && message.phase === "request" ? "preview" : "submit";
+        const value = message.request.kind === "quickPick" ? source : message.request.kind === "input" ? "synthetic output" : undefined;
+        void service.respond(sender, { requestId: message.requestId, actionToken: message.actionToken, action, ...(value === undefined ? {} : { value }) }).catch(() => {});
+      });
+    },
+  });
+  const window = Object.assign(new EventEmitter(), { webContents: sender, isFocused: () => true, isVisible: () => true, isDestroyed: () => false });
+  service = new PluginHostInteractionService({ database, permissionEngine, getWindow: () => window, isLocked: () => false,
+    quotaManager: { chargeBytes() {} },
+    clipboard: { readText() { reads++; return "synthetic private text"; }, writeText(text) { copied.push(text); } },
+  });
+  service.setReady(sender, true);
+  const registry = new PluginHostRpcRegistry();
+  registry.use(permissionEngine.createMiddleware()); service.registerRpcCapabilities(registry);
+  const routes = registry.createRoutes({ pluginId: manifest.id, pluginVersion: manifest.version, runtimeId: "runtime-synthetic", runtimeKind: "browser", manifest,
+    assertCurrent() { if (!active) throw new Error("stale runtime"); },
+  });
+  const { port1, port2 } = new MessageChannel();
+  const host = new PluginRpcRouter({ pluginId: manifest.id, send: (message) => port1.postMessage(message), handlers: routes.requestHandlers });
+  port1.on("message", (message) => { void host.accept(message); });
+  const peer = await startPluginRuntime({ port: port2,
+    config: { pluginId: manifest.id, pluginVersion: manifest.version, netcattyVersion: "0.0.0", apiVersion: "0.1.0-internal.1", enabledFeatures: ["host.interactions"] },
+    loadPlugin: async () => plugin,
+  });
+  try {
+    await host.request("plugin.initialize", { netcattyVersion: "0.0.0", apiVersion: "0.1.0-internal.1", supportedFeatures: ["host.interactions"] });
+    await host.request("plugin.activate", {});
+    const result = await host.request("plugin.command.execute", { command: "com.netcatty.host-interactions.text", invocation: { source: "palette" } });
+    const output = source === "compose" ? "synthetic output" : "SYNTHETIC PRIVATE TEXT";
+    assert.deepEqual(result, { copied: true, characters: output.length });
+    assert.deepEqual(copied, [output]); assert.equal(reads, source === "share" ? 1 : 0);
+    assert.ok(requests.includes("ui.interact")); assert.ok(requests.includes("clipboard.write"));
+    assert.equal(requests.includes("clipboard.read"), source === "share");
+    assert.equal(JSON.stringify(audit).includes("synthetic private text"), false);
+    assert.equal(JSON.stringify(audit).includes("synthetic output"), false);
+    assert.equal(service.pending.size, 0);
+  } finally { active = false; await peer.dispose(); host.close(); port1.close(); service.shutdown(); permissionEngine.shutdown(); }
+});
+
+test("outer command deadline closes its real browser clipboard confirmation and rejects late commit", async () => {
+  const { startPluginRuntime } = await import("./runtime/runtimePeer.mjs");
+  const plugin = await import("../../examples/plugins/host-interactions/browser.js");
+  const manifest = JSON.parse(await readFile(new URL("../../examples/plugins/host-interactions/netcatty.plugin.json", pathToFileURL(__filename)), "utf8"));
+  const identity = { pluginId: manifest.id, pluginVersion: manifest.version, runtimeId: "runtime-deadline", runtimeKind: "browser" };
+  const writes = [], messages = [];
+  const database = { listPermissionGrants: () => [], recordSecurityAudit() {},
+    listPlugins: () => [{ id: manifest.id, activeVersion: manifest.version, manifest, enabled: true, runtime: { status: "running" } }],
+  };
+  const engine = new PluginPermissionEngine({ database, requestDecision: async (request) => ({ requestId: request.requestId, decision: "allow", scope: "once" }) });
+  let service, confirm;
+  const copyPrompt = new Promise((resolve) => { confirm = resolve; });
+  const sender = Object.assign(new EventEmitter(), { id: 8, isDestroyed: () => false, send(_channel, message) {
+    messages.push(message); if (message.closed) return;
+    if (message.request.kind === "clipboard.write") { confirm(message); return; }
+    const value = message.request.kind === "quickPick" ? "compose" : "synthetic pending copy";
+    queueMicrotask(() => { void service.respond(sender, { requestId: message.requestId, actionToken: message.actionToken, action: "submit", value }).catch(() => {}); });
+  } });
+  const owner = Object.assign(new EventEmitter(), { webContents: sender, isFocused: () => true, isVisible: () => true, isDestroyed: () => false });
+  service = new PluginHostInteractionService({ database, permissionEngine: engine, getWindow: () => owner, isLocked: () => false,
+    quotaManager: { chargeBytes() {} }, clipboard: { writeText(text) { writes.push(text); } } });
+  service.setReady(sender, true);
+  const registry = new PluginHostRpcRegistry(); registry.use(engine.createMiddleware()); service.registerRpcCapabilities(registry);
+  const routes = registry.createRoutes({ ...identity, manifest, assertCurrent() {} });
+  const { port1, port2 } = new MessageChannel();
+  const host = new PluginRpcRouter({ pluginId: manifest.id, send: (message) => port1.postMessage(message), handlers: routes.requestHandlers });
+  port1.on("message", (message) => { void host.accept(message); });
+  const features = manifest.features.required;
+  const peer = await startPluginRuntime({ port: port2, config: { ...identity, netcattyVersion: "0.0.0", apiVersion: "0.1.0-internal.1", enabledFeatures: features }, loadPlugin: async () => plugin });
+  try {
+    await host.request("plugin.initialize", { netcattyVersion: "0.0.0", apiVersion: "0.1.0-internal.1", supportedFeatures: features });
+    await host.request("plugin.activate", {});
+    const contributions = new PluginContributionService({ database, onCommandFinished: (runtimeId) => service.cancelRuntimeRequests(runtimeId),
+      runtimeSupervisor: { async start() { return identity; }, request(_pluginId, method, params, options) {
+        assert.equal(options.timeoutMs, 180_000, "host chooses the fixed declared budget");
+        return host.request(method, params, { timeoutMs: 500 }); // bounded synthetic timer, no production timeout change
+      } },
+    });
+    const command = contributions.executeCommand("com.netcatty.host-interactions.text");
+    const prompt = await Promise.race([copyPrompt, command.then(() => { throw new Error("command finished before confirmation"); })]);
+    const attempts = service.rates.get(identity.runtimeId).count;
+    await assert.rejects(command, /timed out/);
+    assert.equal(service.pending.size, 0);
+    assert.equal(service.rates.get(identity.runtimeId).count, attempts);
+    assert.ok(messages.some((message) => message.closed && message.requestId === prompt.requestId));
+    assert.equal(await service.respond(sender, { requestId: prompt.requestId, actionToken: prompt.actionToken, action: "submit" }), false);
+    assert.deepEqual(writes, []);
+    assert.equal(contributions.activeCommandCalls.size, 0);
+  } finally { await peer.dispose(); host.close(); port1.close(); service.shutdown(); engine.shutdown(); }
+});

electron/plugins/hostInteractionService.cjs

@@ -0,0 +1,339 @@
+"use strict";
+
+const { createHmac, randomBytes, randomUUID, timingSafeEqual } = require("node:crypto");
+const { createDefinitionValidator } = require("./contractValidator.cjs");
+const { PluginRpcError, RPC_ERRORS } = require("./rpcRouter.cjs");
+const schema = require("./generated/plugin-contract.schema.json");
+const LIMITS = schema.$defs.HostInteractionLimits.const;
+const HOST_INTERACTION_FEATURE = schema.$defs.HostInteractionFeature.const;
+const validateRequest = createDefinitionValidator("HostInteractionRequest");
+const validateResponse = createDefinitionValidator("HostInteractionResponse");
+const validateResult = createDefinitionValidator("HostInteractionResult");
+const validateSingleLineInput = createDefinitionValidator("HostSingleLineInputText");
+const PROMPT_CHANNEL = "netcatty:plugins:host-interaction";
+
+function fail(code, message) { return new PluginRpcError(RPC_ERRORS[code], message); }
+function assertTextBytes(text) {
+  if (typeof text !== "string" || Buffer.byteLength(text, "utf8") > LIMITS.textBytes || text.includes("\0")) {
+    throw fail("resourceExhausted", "Host interaction text exceeds its limit");
+  }
+  return text;
+}
+function assertInteractionRequest(params) {
+  if (!validateRequest(params)) throw fail("invalidArgument", "Host interaction request is invalid");
+  if (Buffer.byteLength(JSON.stringify(params)) > LIMITS.requestBytes) {
+    throw fail("resourceExhausted", "Host interaction request exceeds its limit");
+  }
+  if (params.kind === "input") assertTextBytes(params.initialValue ?? "");
+  if (params.kind === "clipboard.write") assertTextBytes(params.text);
+  if (params.kind === "quickPick" && new Set(params.items.map((item) => item.id)).size !== params.items.length) {
+    throw fail("invalidArgument", "Host interaction choice IDs must be unique");
+  }
+  return Object.freeze(structuredClone(params));
+}
+function interactionAuthorization(params) {
+  const permission = params.kind === "clipboard.read" ? "clipboard.read"
+    : params.kind === "clipboard.write" ? "clipboard.write" : "ui.interact";
+  return {
+    permission,
+    resources: [permission.startsWith("clipboard.") ? "clipboard:text" : "*"],
+    reason: permission.startsWith("clipboard.") ? "Explicitly share or replace clipboard text" : "Show a host input or choice dialog",
+    operationId: `ui:${params.kind}`,
+    ...(permission.startsWith("clipboard.") ? { allowedScopes: ["once"] } : {}),
+  };
+}
+
+class PluginHostInteractionService {
+  constructor(options) {
+    this.database = options.database;
+    this.permissionEngine = options.permissionEngine;
+    this.quotaManager = options.quotaManager;
+    this.clipboard = options.clipboard;
+    this.getWindow = options.getWindow ?? (() => null);
+    this.isLocked = options.isLocked ?? (() => true);
+    this.clock = options.clock ?? Date.now;
+    this.timeoutMs = Math.min(options.timeoutMs ?? LIMITS.timeoutMs, LIMITS.timeoutMs);
+    this.key = randomBytes(32);
+    this.pending = new Map();
+    this.rates = new Map();
+    this.admissions = new WeakMap();
+    this.admissionGuards = new Map();
+    this.admissionRevision = 0;
+    this.focusRestoreMs = Math.min(options.focusRestoreMs ?? 1_000, 1_000);
+    this.owner = null;
+    this.ownerCleanup = null;
+    this.closed = false;
+    this.revocation = this.permissionEngine.onDidRevoke((event) => this.releasePlugin(event.pluginId));
+    this.unsubscribeLock = options.subscribeLock?.((state) => { if (state.locked) this.cancelAll(); });
+  }
+
+  registerRpcCapabilities(registry) {
+    registry.registerRequest("ui.interact", (params, context) => this.request(params, context), {
+      metadata: { capability: "ui", mutating: true },
+      validateParams: assertInteractionRequest,
+      authorization: (params, context) => {
+        const sender = this.#admit(params, context);
+        let guard = this.admissionGuards.get(context.runtimeId);
+        if (!guard) { guard = { active: true }; this.admissionGuards.set(context.runtimeId, guard); }
+        this.admissions.set(params, { sender, runtimeId: context.runtimeId, revision: this.admissionRevision, guard });
+        return interactionAuthorization(params);
+      },
+    });
+  }
+
+  setReady(sender, ready) {
+    const window = this.getWindow();
+    if (!sender || window?.webContents !== sender || sender.isDestroyed?.()) {
+      throw fail("permissionDenied", "Host interaction window is not the owner");
+    }
+    if (typeof ready !== "boolean") throw fail("invalidArgument", "Host interaction readiness is invalid");
+    if (!ready) { this.releaseWindow(sender); return true; }
+    if (this.closed) throw fail("unavailable", "Host interactions are unavailable");
+    if (this.owner === sender) return true;
+    if (this.owner) this.releaseWindow(this.owner);
+    this.owner = sender;
+    const close = () => this.releaseWindow(sender);
+    // A native permission dialog can temporarily blur its parent. Already
+    // displayed interactions still cancel immediately; pre-prompt admission
+    // can only resume once this same owner actually regains focus.
+    const blur = () => this.cancelAll(false);
+    const hide = () => this.cancelAll();
+    const navigate = (details, _url, isInPlace, isMainFrame) => {
+      const main = details?.isMainFrame ?? isMainFrame;
+      const sameDocument = details?.isSameDocument ?? isInPlace;
+      if (main !== false && sameDocument !== true) close();
+    };
+    sender.once?.("destroyed", close);
+    sender.on?.("did-start-navigation", navigate);
+    sender.on?.("render-process-gone", close);
+    window.on?.("blur", blur);
+    window.on?.("hide", hide);
+    this.ownerCleanup = () => {
+      sender.removeListener?.("destroyed", close);
+      sender.removeListener?.("did-start-navigation", navigate);
+      sender.removeListener?.("render-process-gone", close);
+      window.removeListener?.("blur", blur);
+      window.removeListener?.("hide", hide);
+    };
+    return true;
+  }
+
+  #assertWindow(sender = this.owner) {
+    const window = this.getWindow();
+    if (this.closed || this.isLocked() || !sender || sender !== this.owner
+      || window?.webContents !== sender || window.isDestroyed?.()
+      || sender.isDestroyed?.() || window.isVisible?.() === false || window.isFocused?.() !== true) {
+      throw fail("unavailable", "Host interactions require the focused unlocked main window");
+    }
+    return sender;
+  }
+
+  #token(entry) {
+    const nonce = randomBytes(24).toString("base64url");
+    const binding = JSON.stringify([
+      nonce, entry.id, entry.context.pluginId, entry.context.pluginVersion,
+      entry.context.runtimeId, entry.sender.id, entry.params.kind, entry.phase, entry.expiresAt,
+    ]);
+    return `${nonce}.${createHmac("sha256", this.key).update(binding).digest("base64url")}`;
+  }
+
+  #present(entry) {
+    entry.actionToken = this.#token(entry);
+    entry.sender.send(PROMPT_CHANNEL, {
+      requestId: entry.id, actionToken: entry.actionToken,
+      pluginId: entry.context.pluginId, pluginVersion: entry.context.pluginVersion,
+      expiresAt: entry.expiresAt, phase: entry.phase, request: entry.params,
+      ...(entry.previewText === undefined ? {} : { previewText: entry.previewText }),
+    });
+  }
+
+  #finish(entry, result, error) {
+    if (this.pending.get(entry.id) !== entry) return false;
+    this.pending.delete(entry.id);
+    entry.actionToken = null;
+    entry.previewText = undefined;
+    clearTimeout(entry.timer);
+    entry.context.signal?.removeEventListener("abort", entry.onAbort);
+    try { entry.sender.send(PROMPT_CHANNEL, { requestId: entry.id, closed: true }); } catch {}
+    if (error) entry.reject(error);
+    else if (!validateResult(result)) entry.reject(fail("internal", "Host interaction result is invalid"));
+    else entry.resolve(result);
+    return true;
+  }
+
+  #audit(entry, action) {
+    // Fixed metadata only. Never record title, choices, user input, clipboard
+    // bytes, action token or a hash derived from user content.
+    try {
+      this.database.recordSecurityAudit(entry.context.pluginId, "ui.interaction", { kind: entry.params.kind, action });
+    } catch {
+      throw fail("unavailable", "Host interaction audit is unavailable");
+    }
+  }
+
+  #admit(params, context) {
+    const sender = this.#assertWindow();
+    if ((params.kind === "clipboard.read" && typeof this.clipboard?.readText !== "function")
+      || (params.kind === "clipboard.write" && typeof this.clipboard?.writeText !== "function")) {
+      throw fail("unavailable", "Host clipboard text is unavailable");
+    }
+    const now = this.clock();
+    const rate = this.rates.get(context.runtimeId);
+    const nextRate = !rate || now - rate.startedAt >= 60_000 ? { startedAt: now, count: 0 } : rate;
+    if (nextRate.count >= LIMITS.requestsPerMinute || this.pending.size >= LIMITS.pendingTotal
+      || [...this.pending.values()].some((entry) => entry.context.runtimeId === context.runtimeId || entry.sender === sender)) {
+      throw fail("resourceExhausted", "Host interaction limit reached");
+    }
+    nextRate.count++;
+    this.rates.set(context.runtimeId, nextRate);
+    this.quotaManager.chargeBytes(context.runtimeId, "ui", Buffer.byteLength(JSON.stringify(params)));
+    return sender;
+  }
+
+  async request(params, context) {
+    await context.assertActive();
+    const admission = this.admissions.get(params);
+    this.admissions.delete(params);
+    let sender;
+    if (admission?.runtimeId === context.runtimeId) {
+      // Electron may resolve showMessageBox before restoring parent focus.
+      // Never focus it ourselves or defer an originally background request.
+      // Owner replacement, lock, hide, revoke and runtime stop invalidate this
+      // host-owned admission, including changes during the permission prompt.
+      const deadline = Date.now() + this.focusRestoreMs;
+      for (;;) {
+        context.signal?.throwIfAborted();
+        if (!admission.guard.active || admission.revision !== this.admissionRevision || admission.sender !== this.owner) {
+          throw fail("cancelled", "Host interaction admission was revoked");
+        }
+        const window = this.getWindow();
+        if (this.closed || this.isLocked() || window?.webContents !== admission.sender
+          || window.isDestroyed?.() || admission.sender.isDestroyed?.() || window.isVisible?.() === false) {
+          throw fail("unavailable", "Host interaction owner is unavailable");
+        }
+        if (window.isFocused?.() === true) break;
+        if (Date.now() >= deadline) throw fail("unavailable", "Host interactions require the focused unlocked main window");
+        await new Promise((resolve) => setTimeout(resolve, Math.min(20, Math.max(1, deadline - Date.now()))));
+      }
+      await context.assertActive();
+      if (!admission.guard.active || admission.revision !== this.admissionRevision) throw fail("cancelled", "Host interaction admission was revoked");
+      sender = this.#assertWindow(admission.sender);
+    } else sender = this.#admit(params, context);
+    if (this.pending.size >= LIMITS.pendingTotal || [...this.pending.values()].some((entry) => entry.context.runtimeId === context.runtimeId || entry.sender === sender)) {
+      throw fail("resourceExhausted", "Host interaction limit reached");
+    }
+    const now = this.clock();
+    return new Promise((resolve, reject) => {
+      const entry = {
+        id: randomUUID(), context, params, sender, resolve, reject,
+        expiresAt: now + this.timeoutMs, phase: "request", actionToken: null,
+      };
+      entry.onAbort = () => this.#finish(entry, null, fail("cancelled", "Host interaction was cancelled"));
+      entry.timer = setTimeout(() => this.#finish(entry, null, fail("deadlineExceeded", "Host interaction expired")), this.timeoutMs);
+      entry.timer.unref?.();
+      this.pending.set(entry.id, entry);
+      context.signal?.addEventListener("abort", entry.onAbort, { once: true });
+      if (context.signal?.aborted) { entry.onAbort(); return; }
+      try { this.#present(entry); }
+      catch { this.#finish(entry, null, fail("unavailable", "Host interaction window is unavailable")); }
+    });
+  }
+
+  async respond(sender, response) {
+    this.#assertWindow(sender);
+    if (!validateResponse(response)) throw fail("invalidArgument", "Host interaction response is invalid");
+    const entry = this.pending.get(response.requestId);
+    if (!entry || entry.sender !== sender || !entry.actionToken || this.clock() >= entry.expiresAt) return false;
+    const expected = Buffer.from(entry.actionToken);
+    const supplied = Buffer.from(response.actionToken);
+    if (expected.length !== supplied.length || !timingSafeEqual(expected, supplied)) return false;
+    // Consume before the first asynchronous boundary. Duplicate and old-phase
+    // replies cannot race the same native action.
+    entry.actionToken = null;
+    try {
+      await entry.context.assertActive();
+      this.#assertWindow(sender);
+      if (this.pending.get(entry.id) !== entry) return false;
+      if (response.action === "cancel") {
+        this.#audit(entry, "cancelled");
+        return this.#finish(entry, { cancelled: true });
+      }
+      if (entry.params.kind === "clipboard.read" && entry.phase === "request") {
+        if (response.action !== "preview") throw fail("invalidArgument", "Clipboard sharing requires a preview action");
+        this.#audit(entry, "preview-confirmed");
+        let rawText;
+        try { rawText = this.clipboard.readText(); }
+        catch { throw fail("unavailable", "Host clipboard text is unavailable"); }
+        const text = assertTextBytes(rawText);
+        this.quotaManager.chargeBytes(entry.context.runtimeId, "clipboard", Buffer.byteLength(text));
+        entry.previewText = text;
+        entry.phase = "preview";
+        try { this.#present(entry); }
+        catch { throw fail("unavailable", "Host interaction window is unavailable"); }
+        return true;
+      }
+      if (response.action !== "submit") throw fail("invalidArgument", "Host interaction action is invalid");
+      let value;
+      if (entry.params.kind === "input") {
+        if (!validateSingleLineInput(response.value)) throw fail("invalidArgument", "Host input must be a single line");
+        value = assertTextBytes(response.value);
+      }
+      else if (entry.params.kind === "quickPick") {
+        if (!entry.params.items.some((item) => item.id === response.value)) throw fail("invalidArgument", "Host interaction choice is invalid");
+        value = response.value;
+      } else if (entry.params.kind === "clipboard.read") value = entry.previewText;
+      else value = true;
+      this.#audit(entry, entry.params.kind === "clipboard.write" ? "copy-confirmed" : "share-confirmed");
+      if (entry.params.kind === "clipboard.write") {
+        try { this.clipboard.writeText(entry.params.text); }
+        catch { throw fail("unavailable", "Host clipboard write failed"); }
+      }
+      return this.#finish(entry, { cancelled: false, value });
+    } catch (error) {
+      this.#finish(entry, null, error);
+      throw error;
+    }
+  }
+
+  releaseWindow(sender) {
+    if (this.owner !== sender) return;
+    this.admissionRevision++;
+    this.owner = null;
+    this.ownerCleanup?.(); this.ownerCleanup = null;
+    for (const entry of [...this.pending.values()]) {
+      if (entry.sender === sender) this.#finish(entry, null, fail("cancelled", "Host interaction window closed"));
+    }
+  }
+  releasePlugin(pluginId) {
+    this.admissionRevision++;
+    for (const entry of [...this.pending.values()]) {
+      if (entry.context.pluginId === pluginId) this.#finish(entry, null, fail("cancelled", "Plugin access was revoked"));
+    }
+  }
+  releaseRuntime(runtimeId) {
+    this.cancelRuntimeRequests(runtimeId, "Plugin runtime stopped");
+    this.rates.delete(runtimeId);
+  }
+  cancelRuntimeRequests(runtimeId, reason = "Host command finished") {
+    const guard = this.admissionGuards.get(runtimeId);
+    if (guard) guard.active = false;
+    this.admissionGuards.delete(runtimeId);
+    for (const entry of [...this.pending.values()]) {
+      if (entry.context.runtimeId === runtimeId) this.#finish(entry, null, fail("cancelled", reason));
+    }
+  }
+  cancelAll(invalidateAdmission = true) {
+    if (invalidateAdmission) this.admissionRevision++;
+    for (const entry of [...this.pending.values()]) this.#finish(entry, null, fail("cancelled", "Host interaction was cancelled"));
+  }
+  shutdown() {
+    if (this.closed) return;
+    this.closed = true;
+    if (this.owner) this.releaseWindow(this.owner);
+    this.cancelAll(); this.rates.clear(); this.admissionGuards.clear();
+    this.revocation.dispose(); this.unsubscribeLock?.();
+    this.key.fill(0);
+  }
+}
+
+module.exports = { HOST_INTERACTION_FEATURE, LIMITS, PROMPT_CHANNEL, PluginHostInteractionService, assertInteractionRequest, interactionAuthorization };

electron/plugins/hostInteractionService.test.cjs

@@ -0,0 +1,301 @@
+"use strict";
+const assert = require("node:assert/strict");
+const { EventEmitter } = require("node:events");
+const test = require("node:test");
+const { PluginHostInteractionService, assertInteractionRequest, interactionAuthorization, PROMPT_CHANNEL } = require("./hostInteractionService.cjs");
+
+function fixture(t, options = {}) {
+  const messages = [], audit = [], writes = [], charges = [];
+  let reads = 0, locked = false, focused = true, active = true;
+  const sender = Object.assign(new EventEmitter(), { id: 7, isDestroyed: () => false, send: (channel, message) => { assert.equal(channel, PROMPT_CHANNEL); messages.push(message); } });
+  const window = Object.assign(new EventEmitter(), { webContents: sender, isFocused: () => focused, isVisible: () => true, isDestroyed: () => false });
+  const signal = new AbortController();
+  let onRevoke;
+  const service = new PluginHostInteractionService({
+    getWindow: () => window, isLocked: () => locked,
+    permissionEngine: { onDidRevoke(fn) { onRevoke = fn; return { dispose() {} }; } },
+    database: { recordSecurityAudit(...args) { audit.push(args); } },
+    quotaManager: { chargeBytes(...args) { charges.push(args); } },
+    clipboard: { readText() { reads++; return "synthetic clipboard"; }, writeText(text) { writes.push(text); } },
+    ...options,
+  });
+  service.setReady(sender, true);
+  t.after(() => service.shutdown());
+  const context = {
+    pluginId: "com.example.synthetic", pluginVersion: "1.0.0", runtimeId: "runtime-synthetic", signal: signal.signal,
+    async assertActive() { signal.signal.throwIfAborted(); if (!active) throw new Error("stale runtime"); },
+  };
+  const begin = async (params) => {
+    const promise = service.request(assertInteractionRequest(params), context);
+    void promise.catch(() => {});
+    await new Promise((resolve) => setImmediate(resolve));
+    return { promise, prompt: messages.filter((message) => !message.closed).at(-1) };
+  };
+  const respond = (prompt, action, value) => service.respond(sender, { requestId: prompt.requestId, actionToken: prompt.actionToken, action, ...(value === undefined ? {} : { value }) });
+  return { service, sender, window, context, messages, audit, writes, charges, begin, respond, signal,
+    get reads() { return reads; }, revoke() { onRevoke({ pluginId: context.pluginId }); },
+    lock() { locked = true; }, blur() { focused = false; window.emit("blur"); }, focus() { focused = true; window.emit("focus"); }, stale() { active = false; },
+  };
+}
+
+test("normal input and quick pick return only an approved bounded value", async (t) => {
+  const f = fixture(t);
+  const input = await f.begin({ kind: "input", title: "Synthetic input", initialValue: "draft" });
+  assert.equal(await f.respond(input.prompt, "submit", "approved"), true);
+  assert.deepEqual(await input.promise, { cancelled: false, value: "approved" });
+  const choice = await f.begin({ kind: "quickPick", title: "Pick", items: [{ id: "one", label: "One" }] });
+  assert.equal(await f.respond(choice.prompt, "submit", "one"), true);
+  assert.deepEqual(await choice.promise, { cancelled: false, value: "one" });
+  assert.equal(JSON.stringify(f.audit).includes("approved"), false);
+  assert.equal(f.reads, 0); assert.deepEqual(f.writes, []);
+});
+
+test("ending a host command cancels pending native actions without resetting its quota", async (t) => {
+  const f = fixture(t);
+  const request = await f.begin({ kind: "clipboard.write", title: "Synthetic", text: "must not copy" });
+  const count = f.service.rates.get(f.context.runtimeId).count;
+  f.service.cancelRuntimeRequests(f.context.runtimeId);
+  await assert.rejects(request.promise, /command finished/);
+  assert.equal(await f.respond(request.prompt, "submit"), false);
+  assert.deepEqual(f.writes, []);
+  assert.equal(f.service.rates.get(f.context.runtimeId).count, count);
+});
+
+test("old command completion cannot invalidate a replacement runtime's host-owned admission", async (t) => {
+  const f = fixture(t);
+  let authorize;
+  f.service.registerRpcCapabilities({ registerRequest(_name, _handler, options) { authorize = options.authorization; } });
+  const old = assertInteractionRequest({ kind: "input", title: "Old" });
+  authorize(old, f.context);
+  f.service.cancelRuntimeRequests(f.context.runtimeId);
+  await assert.rejects(f.service.request(old, f.context), /revoked/);
+  const nextContext = { ...f.context, runtimeId: "runtime-replacement" };
+  const next = assertInteractionRequest({ kind: "input", title: "New" });
+  authorize(next, nextContext);
+  f.service.cancelRuntimeRequests(f.context.runtimeId);
+  const request = f.service.request(next, nextContext);
+  await new Promise((resolve) => setImmediate(resolve));
+  const prompt = f.messages.find((message) => !message.closed);
+  assert.ok(prompt);
+  await f.respond(prompt, "submit", "synthetic new input");
+  assert.deepEqual(await request, { cancelled: false, value: "synthetic new input" });
+});
+
+test("Once permission dialog may restore the same owner's focus after its decision resolves", async (t) => {
+  const { PluginHostRpcRegistry } = require("./hostRpcRegistry.cjs");
+  const { PluginPermissionEngine } = require("./permissionEngine.cjs");
+  const f = fixture(t);
+  let decisions = 0;
+  const engine = new PluginPermissionEngine({
+    database: { listPermissionGrants: () => [], recordSecurityAudit() {} },
+    requestDecision: async (request) => {
+      decisions++;
+      f.blur();
+      setTimeout(() => f.focus(), 30);
+      return { requestId: request.requestId, decision: "allow", scope: "once" };
+    },
+  });
+  t.after(() => engine.shutdown());
+  const registry = new PluginHostRpcRegistry();
+  registry.use(engine.createMiddleware());
+  f.service.registerRpcCapabilities(registry);
+  const route = registry.createRoutes({ ...f.context, runtimeKind: "browser", assertCurrent() {},
+    manifest: { id: f.context.pluginId, publisher: "example", permissions: { optional: ["ui.interact"] } },
+  }).requestHandlers["ui.interact"];
+  const result = route({ kind: "input", title: "Synthetic input", initialValue: "visible" }, { signal: f.context.signal });
+  await new Promise((resolve) => setTimeout(resolve, 10));
+  assert.equal(f.messages.length, 0, "no dialog is delivered while the owner is backgrounded");
+  await new Promise((resolve) => setTimeout(resolve, 45));
+  const prompt = f.messages.find((message) => !message.closed);
+  assert.ok(prompt);
+  await f.respond(prompt, "submit", "visible");
+  assert.deepEqual(await result, { cancelled: false, value: "visible" });
+  assert.equal(decisions, 1);
+  assert.equal(f.reads, 0); assert.deepEqual(f.writes, []);
+});
+
+test("focus restoration is bounded and admission cannot survive owner or access lifecycle changes", async (t) => {
+  for (const action of ["timeout", "hide", "revoke", "runtime", "window", "lock", "signal", "stale"]) {
+    const f = fixture(t, { focusRestoreMs: 35 });
+    let authorize;
+    f.service.registerRpcCapabilities({ registerRequest(_name, _handler, options) { authorize = options.authorization; } });
+    const params = assertInteractionRequest({ kind: "clipboard.write", title: "Never copied", text: "synthetic" });
+    authorize(params, f.context); // admission is host-owned and originally foregrounded
+    f.blur();
+    const result = f.service.request(params, f.context);
+    void result.catch(() => {});
+    await new Promise((resolve) => setTimeout(resolve, 5));
+    if (action === "hide") f.window.emit("hide");
+    if (action === "revoke") f.revoke();
+    if (action === "runtime") f.service.releaseRuntime(f.context.runtimeId);
+    if (action === "window") { f.sender.emit("did-start-navigation", { isMainFrame: true, isSameDocument: false }); f.service.setReady(f.sender, true); }
+    if (action === "lock") f.lock();
+    if (action === "signal") f.signal.abort();
+    if (action === "stale") f.stale();
+    if (action !== "timeout") f.focus();
+    await assert.rejects(result, /focused unlocked|revoked|unavailable|abort|stale/i, action);
+    assert.equal(f.messages.length, 0, action);
+    assert.deepEqual(f.writes, []); assert.equal(f.reads, 0);
+  }
+  const background = fixture(t);
+  background.blur();
+  await assert.rejects(background.service.request(assertInteractionRequest({ kind: "input", title: "Background" }), background.context), /focused unlocked/);
+});
+
+test("clipboard read waits for preview action and a separate single-use sharing confirmation", async (t) => {
+  const f = fixture(t);
+  const request = await f.begin({ kind: "clipboard.read", title: "Share text" });
+  let done = false; void request.promise.then(() => { done = true; });
+  assert.equal(f.reads, 0);
+  await f.respond(request.prompt, "preview");
+  const preview = f.messages.filter((message) => !message.closed).at(-1);
+  assert.equal(preview.phase, "preview"); assert.equal(preview.previewText, "synthetic clipboard");
+  assert.notEqual(preview.actionToken, request.prompt.actionToken);
+  assert.equal(f.reads, 1); assert.equal(done, false);
+  assert.equal(await f.respond(request.prompt, "submit"), false, "old-phase action cannot share text");
+  assert.equal(await f.respond(preview, "submit"), true);
+  assert.deepEqual(await request.promise, { cancelled: false, value: "synthetic clipboard" });
+  assert.equal(await f.respond(preview, "submit"), false, "no replay");
+  assert.equal(f.reads, 1); assert.equal(JSON.stringify(f.audit).includes("synthetic clipboard"), false);
+});
+
+test("clipboard copy is explicit and duplicate replies write once", async (t) => {
+  const f = fixture(t);
+  const request = await f.begin({ kind: "clipboard.write", title: "Copy", text: "synthetic output" });
+  assert.deepEqual(f.writes, []);
+  const first = f.respond(request.prompt, "submit");
+  assert.equal(await f.respond(request.prompt, "submit"), false);
+  assert.equal(await first, true);
+  assert.deepEqual(await request.promise, { cancelled: false, value: true });
+  assert.deepEqual(f.writes, ["synthetic output"]);
+});
+
+test("cancel, blur, revoke, runtime release, and incoming cancellation revoke pending action tokens", async (t) => {
+  for (const action of ["cancel", "blur", "revoke", "runtime", "signal", "window"]) {
+    const f = fixture(t);
+    const request = await f.begin({ kind: "clipboard.write", title: "Copy", text: "never written" });
+    if (action === "cancel") { await f.respond(request.prompt, "cancel"); assert.deepEqual(await request.promise, { cancelled: true }); }
+    else {
+      if (action === "blur") f.blur();
+      if (action === "revoke") f.revoke();
+      if (action === "runtime") f.service.releaseRuntime(f.context.runtimeId);
+      if (action === "signal") f.signal.abort();
+      if (action === "window") f.sender.emit("destroyed");
+      await assert.rejects(request.promise, /cancelled|revoked|stopped|closed/);
+    }
+    assert.deepEqual(f.writes, []);
+    assert.equal(f.service.pending.size, 0);
+  }
+});
+
+test("wrong windows, forged tokens and stale runtimes cannot commit a native action", async (t) => {
+  const f = fixture(t);
+  const request = await f.begin({ kind: "clipboard.write", title: "Copy", text: "never written" });
+  await assert.rejects(f.service.respond({ id: 9 }, { requestId: request.prompt.requestId, actionToken: request.prompt.actionToken, action: "submit" }), /focused unlocked/);
+  assert.equal(await f.respond({ ...request.prompt, actionToken: "x".repeat(64) }, "submit"), false);
+  f.stale();
+  await assert.rejects(f.respond(request.prompt, "submit"), /stale runtime/);
+  await assert.rejects(request.promise, /stale runtime/);
+  assert.deepEqual(f.writes, []);
+});
+
+test("quota, deadline, locked host, unknown fields, duplicate choices and text bounds fail closed", async (t) => {
+  const f = fixture(t, { timeoutMs: 20 });
+  const request = await f.begin({ kind: "input", title: "Input" });
+  await assert.rejects(f.service.request(assertInteractionRequest({ kind: "input", title: "Another" }), f.context), /limit/);
+  const keepAlive = setTimeout(() => {}, 100);
+  await assert.rejects(request.promise, /expired/); clearTimeout(keepAlive);
+  f.lock();
+  await assert.rejects(f.service.request(assertInteractionRequest({ kind: "input", title: "Locked" }), f.context), /focused unlocked/);
+  assert.throws(() => assertInteractionRequest({ kind: "clipboard.read", title: "Forged", userGesture: true }), /invalid/);
+  assert.throws(() => assertInteractionRequest({ kind: "quickPick", title: "Duplicate", items: [{ id: "same", label: "A" }, { id: "same", label: "B" }] }), /unique/);
+  assert.throws(() => assertInteractionRequest({ kind: "clipboard.write", title: "Too long", text: "文".repeat(1500) }), /limit/);
+  assert.equal(interactionAuthorization({ kind: "clipboard.read" }).permission, "clipboard.read");
+  assert.equal(interactionAuthorization({ kind: "clipboard.write" }).permission, "clipboard.write");
+  assert.equal(interactionAuthorization({ kind: "input" }).permission, "ui.interact");
+});
+
+test("manifest permission checks and interaction quota run before any host prompt", async (t) => {
+  const { PluginHostRpcRegistry } = require("./hostRpcRegistry.cjs");
+  const { PluginPermissionEngine } = require("./permissionEngine.cjs");
+  const f = fixture(t);
+  let decisions = 0;
+  const engine = new PluginPermissionEngine({
+    database: { listPermissionGrants: () => [], recordSecurityAudit() {} },
+    requestDecision: async (request) => { decisions++; return { requestId: request.requestId, decision: "deny" }; },
+  });
+  t.after(() => engine.shutdown());
+  const registry = new PluginHostRpcRegistry();
+  registry.use(engine.createMiddleware());
+  f.service.registerRpcCapabilities(registry);
+  const base = { ...f.context, runtimeKind: "browser", manifest: { id: f.context.pluginId, publisher: "example", permissions: {} }, assertCurrent() {} };
+  const denied = registry.createRoutes(base).requestHandlers["ui.interact"];
+  await assert.rejects(denied({ kind: "input", title: "Undeclared" }, { signal: f.context.signal }), /declare/);
+  assert.equal(decisions, 0); assert.equal(f.messages.length, 0);
+  const route = registry.createRoutes({ ...base, manifest: { ...base.manifest, permissions: { optional: ["ui.interact"] } } }).requestHandlers["ui.interact"];
+  for (let count = 1; count < 10; count++) {
+    await assert.rejects(route({ kind: "input", title: "Denied" }, { signal: f.context.signal }), /denied/);
+  }
+  const before = decisions;
+  await assert.rejects(route({ kind: "input", title: "Over quota" }, { signal: f.context.signal }), /limit/);
+  assert.equal(decisions, before, "over-quota work cannot open another permission prompt");
+  assert.equal(f.messages.length, 0);
+});
+
+test("revoke during an asynchronous active guard and audit failure cannot write clipboard", async (t) => {
+  const f = fixture(t);
+  const request = await f.begin({ kind: "clipboard.write", title: "Copy", text: "never copied" });
+  let resume;
+  f.context.assertActive = () => new Promise((resolve) => { resume = resolve; });
+  const reply = f.respond(request.prompt, "submit");
+  f.revoke();
+  resume();
+  assert.equal(await reply, false);
+  await assert.rejects(request.promise, /revoked/);
+  assert.deepEqual(f.writes, []);
+  const g = fixture(t, { database: { recordSecurityAudit() { throw new Error("synthetic audit failure"); } } });
+  const failed = await g.begin({ kind: "clipboard.write", title: "Copy", text: "never copied" });
+  await assert.rejects(g.respond(failed.prompt, "submit"), /audit is unavailable/);
+  await assert.rejects(failed.promise, /audit is unavailable/);
+  assert.deepEqual(g.writes, []);
+});
+
+test("same-document navigation keeps ownership, while document reload and renderer exit cancel it", async (t) => {
+  for (const event of ["reload", "renderer"]) {
+    const f = fixture(t);
+    const request = await f.begin({ kind: "clipboard.read", title: "Share" });
+    f.sender.emit("did-start-navigation", { isMainFrame: false, isSameDocument: false });
+    f.sender.emit("did-start-navigation", { isMainFrame: true, isSameDocument: true });
+    assert.equal(f.service.pending.size, 1);
+    if (event === "reload") f.sender.emit("did-start-navigation", { isMainFrame: true, isSameDocument: false });
+    else f.sender.emit("render-process-gone");
+    await assert.rejects(request.promise, /window closed/);
+    assert.equal(f.reads, 0); assert.equal(f.service.owner, null);
+  }
+});
+
+test("host lock subscription cancels previewed text before it can be shared", async (t) => {
+  let changed;
+  const f = fixture(t, { subscribeLock(listener) { changed = listener; return () => {}; } });
+  const request = await f.begin({ kind: "clipboard.read", title: "Share" });
+  await f.respond(request.prompt, "preview");
+  const preview = f.messages.filter((message) => !message.closed).at(-1);
+  changed({ locked: true });
+  await assert.rejects(request.promise, /cancelled/);
+  assert.equal(await f.respond(preview, "submit"), false);
+  assert.equal(f.reads, 1); assert.equal(f.service.pending.size, 0);
+});
+
+test("single-line inputs reject CR/LF before display and submission while clipboard text stays multiline", async (t) => {
+  const f = fixture(t);
+  for (const text of ["first\nsecond", "first\rsecond", "first\r\nsecond"]) {
+    assert.throws(() => assertInteractionRequest({ kind: "input", title: "Single line", initialValue: text }), /invalid/);
+    const request = await f.begin({ kind: "input", title: "Single line", initialValue: "first second" });
+    await assert.rejects(f.respond(request.prompt, "submit", text), /single line/);
+    await assert.rejects(request.promise, /single line/);
+  }
+  const copy = await f.begin({ kind: "clipboard.write", title: "Multiline clipboard", text: "first\nsecond" });
+  await f.respond(copy.prompt, "submit");
+  assert.deepEqual(await copy.promise, { cancelled: false, value: true });
+  assert.deepEqual(f.writes, ["first\nsecond"]);
+});

electron/plugins/hostService.cjs

@@ -2,6 +2,7 @@
 
 const path = require("node:path");
 const NETWORK_CREDENTIAL_LEASE_FEATURE = require("./generated/plugin-contract.schema.json").$defs.NetworkCredentialLeaseFeature.const;
+const INTERACTIVE_COMMAND_FEATURE = require("./generated/plugin-contract.schema.json").$defs.InteractiveCommandFeature.const;
 
 const { assertBrowserOnlyPlugin } = require("../../domain/pluginRuntimePolicy.cjs");
 const { isPluginDevelopmentEnabled, PLUGIN_API_VERSION } = require("./constants.cjs");
@@ -23,6 +24,7 @@ const { PackageStore } = require("./packageStore.cjs");
 const { createPluginPaths } = require("./paths.cjs");
 const { PluginManager } = require("./pluginManager.cjs");
 const { PluginNetworkBroker } = require("./networkBroker.cjs");
+const { HOST_INTERACTION_FEATURE, PluginHostInteractionService } = require("./hostInteractionService.cjs");
 const { PluginPermissionEngine } = require("./permissionEngine.cjs");
 const { PluginProtocol } = require("./pluginProtocol.cjs");
 const { PluginViewHost } = require("./pluginViewHost.cjs");
@@ -86,6 +88,7 @@ function createPluginHostService(options) {
   const appRoot = options.appRoot ?? options.app.getAppPath();
   const runtimeDirectory = options.runtimeDirectory ?? path.join(__dirname, "runtime");
   const database = new PluginDatabase(paths.database);
+  let interactionService;
   try {
     const packageStore = new PackageStore({
       allowAdvancedPlugins,
@@ -93,7 +96,7 @@ function createPluginHostService(options) {
       database,
       netcattyVersion: options.app.getVersion(),
       apiVersion: PLUGIN_API_VERSION,
-      supportedFeatures: [...new Set(["metadata.brand-icon", NETWORK_CREDENTIAL_LEASE_FEATURE, ...(options.supportedFeatures ?? [])])],
+      supportedFeatures: [...new Set(["metadata.brand-icon", NETWORK_CREDENTIAL_LEASE_FEATURE, HOST_INTERACTION_FEATURE, INTERACTIVE_COMMAND_FEATURE, ...(options.supportedFeatures ?? [])])],
     });
     const contributionIconService = new PluginContributionIconService({
       database,
@@ -165,6 +168,7 @@ function createPluginHostService(options) {
       runtimeSupervisor: runtimeAccess,
       secretStore,
       getLocale: options.getLocale,
+      onCommandFinished: (runtimeId) => interactionService?.cancelRuntimeRequests(runtimeId),
     });
     contributionService.registerRpcCapabilities(rpcRegistry);
     registerSecurePluginCapabilities(rpcRegistry, {
@@ -177,6 +181,14 @@ function createPluginHostService(options) {
       quotaManager,
       secretStore,
     });
+    interactionService = new PluginHostInteractionService({
+      database, permissionEngine, quotaManager,
+      clipboard: options.electron.clipboard,
+      getWindow: options.getInteractionWindow,
+      isLocked: options.isAppLocked,
+      subscribeLock: options.subscribeAppLock,
+    });
+    interactionService.registerRpcCapabilities(rpcRegistry);
     const configuredRegistry = options.configureRpcRegistry?.(rpcRegistry);
     if (configuredRegistry && typeof configuredRegistry.then === "function") {
       throw new TypeError("Plugin host RPC registry configuration must be synchronous");
@@ -224,7 +236,7 @@ function createPluginHostService(options) {
       paths,
       netcattyVersion: options.app.getVersion(),
       apiVersion: PLUGIN_API_VERSION,
-      supportedFeatures: [...new Set(["metadata.brand-icon", NETWORK_CREDENTIAL_LEASE_FEATURE, ...(options.supportedFeatures ?? [])])],
+      supportedFeatures: [...new Set(["metadata.brand-icon", NETWORK_CREDENTIAL_LEASE_FEATURE, HOST_INTERACTION_FEATURE, INTERACTIVE_COMMAND_FEATURE, ...(options.supportedFeatures ?? [])])],
       runtimeDirectory,
       appRoot,
       rpcRegistry,
@@ -234,6 +246,7 @@ function createPluginHostService(options) {
       getInitialEnvironment: () => contributionService.getEnvironment(),
       runtimeResourceMonitor: quotaManager,
       runtimeCleanup: async (identity) => {
+        interactionService?.releaseRuntime(identity.runtimeId);
         leaseStore.revokeRuntime(identity.runtimeId);
         await companionSupervisor.releaseRuntime(identity.runtimeId);
       },
@@ -360,6 +373,7 @@ function createPluginHostService(options) {
       runtimeSupervisor,
       contributionService,
       beforeClose: async () => {
+        interactionService.shutdown();
         terminalDataPipelineService?.shutdown();
         extensionProviderService.shutdown();
         credentialResolver.shutdown?.();
@@ -371,6 +385,7 @@ function createPluginHostService(options) {
       },
     });
     return {
+      interactionService,
       catalogService: new RegistryCatalogService({ manager, fetch: options.electron.net?.fetch?.bind(options.electron.net) }),
       companionSupervisor,
       contributionIconService,
@@ -398,6 +413,7 @@ function createPluginHostService(options) {
       viewHost,
     };
   } catch (error) {
+    try { interactionService?.shutdown(); } catch {}
     database.close();
     throw error;
   }

electron/plugins/pluginBridge.cjs

@@ -16,6 +16,8 @@ const { assertSecretKey } = require("./secretStore.cjs");
 
 const CHANNELS = Object.freeze({
   status: "netcatty:plugins:status",
+  interactionReady: "netcatty:plugins:interaction-ready",
+  interactionResponse: "netcatty:plugins:interaction-response",
   list: "netcatty:plugins:list",
   permissions: "netcatty:plugins:permissions",
   revokePermissions: "netcatty:plugins:revoke-permissions",
@@ -661,6 +663,14 @@ function registerPluginBridge(ipcMain, options) {
     if (!options.catalogService) throw new Error("Plugin catalog unavailable");
     return options.catalogService.install(payload?.id, payload?.selectionToken);
   });
+  handle(CHANNELS.interactionReady, async (_manager, payload, event) => {
+    if (!options.interactionService) throw new Error("Host interactions are unavailable");
+    return options.interactionService.setReady(event.sender, payload?.ready);
+  });
+  handle(CHANNELS.interactionResponse, async (_manager, payload, event) => {
+    if (!options.interactionService) throw new Error("Host interactions are unavailable");
+    return options.interactionService.respond(event.sender, payload);
+  });
   handle(CHANNELS.list, async (activeManager) => activeManager.list());
   const assertManagedPluginId = (payload) => {
     const id = payload?.pluginId;

electron/plugins/pluginBridge.test.cjs

@@ -1694,3 +1694,23 @@ test("grant classification uses only the current host activation and stops match
   await read({}, payload);
   assert.equal(contexts[3], null, "stopped and lazy plugins show saved grants as inactive");
 });
+
+test("host interaction ready and response channels reject untrusted senders before touching the adapter", async () => {
+  const ipcMain = createIpcMain(), calls = [];
+  const sender = { id: 7 };
+  registerPluginBridge(ipcMain, {
+    manager: { async initialize() {} }, isTrustedSender: (event) => event?.trusted === true,
+    interactionService: {
+      setReady(...args) { calls.push(args); return true; },
+      respond(...args) { calls.push(args); return true; },
+    },
+  });
+  for (const channel of [CHANNELS.interactionReady, CHANNELS.interactionResponse]) {
+    await assert.rejects(ipcMain.handlers.get(channel)({ sender }, {}), /Untrusted/);
+  }
+  assert.deepEqual(calls, []);
+  await ipcMain.handlers.get(CHANNELS.interactionReady)({ trusted: true, sender }, { ready: true });
+  const response = { requestId: "opaque", actionToken: "host-token", action: "cancel" };
+  await ipcMain.handlers.get(CHANNELS.interactionResponse)({ trusted: true, sender }, response);
+  assert.deepEqual(calls, [[sender, true], [sender, response]]);
+});

electron/plugins/runtime/runtimePeer.mjs

@@ -5,7 +5,7 @@ import {
   PLUGIN_ERROR_WIRE_CODES,
   pluginErrorToRpcError,
 } from "@netcatty/plugin-sdk";
-import { createMessagePortStreamEnvelope } from "@netcatty/plugin-contract";
+import { createMessagePortStreamEnvelope, PLUGIN_HOST_INTERACTION_LIMITS } from "@netcatty/plugin-contract";
 import { createPluginStreamEndpoint } from "./pluginStreamEndpoint.mjs";
 
 let terminalInterceptorTransportPromise;
@@ -365,6 +365,16 @@ function createPluginContext(config, client, runtimeApi) {
       ...(options?.ttlMs === undefined ? {} : { ttlMs: options.ttlMs }),
     }),
   };
+  const interact = (params) => client.request("ui.interact", params, { deadlineMs: PLUGIN_HOST_INTERACTION_LIMITS.timeoutMs })
+    .then((result) => result.cancelled ? undefined : result.value);
+  const ui = {
+    quickPick: (title, items) => interact({ kind: "quickPick", title, items }),
+    input: (title, initialValue) => interact({ kind: "input", title, ...(initialValue === undefined ? {} : { initialValue }) }),
+  };
+  const clipboard = {
+    readText: (title) => interact({ kind: "clipboard.read", title }),
+    writeText: (text, title) => interact({ kind: "clipboard.write", title, text }).then((value) => value === true),
+  };
   const network = {
     request: (request) => client.request("network.request", request, {
       deadlineMs: forwardedDeadline(request?.timeoutMs, 300_000),
@@ -543,6 +553,8 @@ function createPluginContext(config, client, runtimeApi) {
     secrets,
     credentials,
     network,
+    ui,
+    clipboard,
     filesystem,
     companions,
     streams,

electron/plugins/runtimeSupervisor.test.cjs

@@ -12,6 +12,7 @@ const { createPluginPaths } = require("./paths.cjs");
 const { RPC_ERRORS } = require("./rpcRouter.cjs");
 const { RuntimeSupervisor } = require("./runtimeSupervisor.cjs");
 const { createContainmentError } = require("./utilityPluginRuntime.cjs");
+const { PluginContributionService } = require("./contributionService.cjs");
 
 function pluginManifest(overrides = {}) {
   return {
@@ -66,6 +67,31 @@ function createFixture(context, runtimeFactory, supervisorOptions = {}) {
   return { database, manifest, runtimeOptions, supervisor };
 }
 
+test("ordinary command activation A cannot dispatch on replacement runtime B", async (t) => {
+  let executed = 0, activation;
+  const fixture = createFixture(t, () => ({ async start(config) { return { pluginId: config.pluginId, pluginVersion: config.pluginVersion,
+    apiVersion: config.apiVersion, enabledFeatures: config.enabledFeatures }; }, async stop() {}, async request() { executed++; return null; } }));
+  t.after(() => fixture.supervisor.shutdown());
+  const manifest = { ...fixture.manifest, contributes: { commands: [{ id: `${fixture.manifest.id}.ordinary`, title: "Ordinary" }] } };
+  const finished = [];
+  const service = new PluginContributionService({
+    database: { listPlugins: () => [{ id: manifest.id, manifest, activeVersion: manifest.version, enabled: true, runtime: {} }] },
+    onCommandFinished: (runtimeId) => finished.push(runtimeId),
+    runtimeSupervisor: {
+      async start(pluginId) {
+        activation = await fixture.supervisor.start(pluginId);
+        await fixture.supervisor.restart(pluginId);
+        return activation;
+      },
+      request: (...args) => fixture.supervisor.request(...args),
+    },
+  });
+  await assert.rejects(service.executeCommand(`${manifest.id}.ordinary`), /no longer matches the authorized activation/);
+  assert.notEqual(fixture.supervisor.getRuntimeIdentity(manifest.id).runtimeId, activation.runtimeId);
+  assert.equal(executed, 0, "replacement B receives no stale command");
+  assert.deepEqual(finished, [activation.runtimeId]);
+});
+
 test("supervisor prefers the ordinary browser runtime and enforces negotiated identity", async (context) => {
   const calls = [];
   const initialEnvironment = { locale: "en", theme: "light", reducedMotion: false, highContrast: false };

electron/preload/api.cjs

@@ -102,6 +102,13 @@ function createPreloadApi(ctx) {
   listPluginCatalog: () => ipcRenderer.invoke("netcatty:plugins:catalog"),
   getPluginCatalogReadme: (id, selectionToken) => ipcRenderer.invoke("netcatty:plugins:catalog-readme", { id, selectionToken }),
   installCatalogPlugin: (id, selectionToken) => ipcRenderer.invoke("netcatty:plugins:catalog-install", { id, selectionToken }),
+  setPluginInteractionReady: (ready) => ipcRenderer.invoke("netcatty:plugins:interaction-ready", { ready }),
+  respondPluginInteraction: (response) => ipcRenderer.invoke("netcatty:plugins:interaction-response", response),
+  onPluginInteraction: (callback) => {
+    const listener = (_event, payload) => callback(payload);
+    ipcRenderer.on("netcatty:plugins:host-interaction", listener);
+    return () => ipcRenderer.removeListener("netcatty:plugins:host-interaction", listener);
+  },
   listPlugins: () => ipcRenderer.invoke("netcatty:plugins:list"),
   getPluginPermissions: (pluginId) => ipcRenderer.invoke("netcatty:plugins:permissions", { pluginId }),
   revokePluginPermissions: (pluginId) => ipcRenderer.invoke("netcatty:plugins:revoke-permissions", { pluginId }),

examples/plugins/host-interactions/README.md

@@ -0,0 +1,41 @@
+# Host text workflow
+
+This browser-only fixture uses host choice/input dialogs and explicit clipboard
+copy/share. It has no network, filesystem, host/session, credential, Node, or
+shell permission. Shared text stays in the current operation's memory and is
+not returned in the command result or written to plugin storage/logs.
+
+Version 0.1.1 requires `host.interactions` and `commands.interactive`. Its one
+command explicitly declares the fixed 180-second interactive budget; ordinary
+commands keep 30 seconds and each dialog keeps 60 seconds. The host closes
+pending confirmations when the command fails or ends, without resetting quotas.
+These features add no new data permission. The permission list remains
+required `commands`/`menus`, optional `ui.interact`/`clipboard.read`/`clipboard.write`.
+
+Pack the source after building the plugin packages:
+
+```sh
+node packages/plugin-cli/dist/cli.js pack examples/plugins/host-interactions --out /tmp/host-interactions.ncpkg
+```
+
+Import it disabled in the normal manager. Inspect permissions before enabling.
+Use one-use permissions for this check. With the unlocked main window focused,
+choose **Host text workflow** in the command palette.
+
+- **Compose synthetic text** asks for text and then previews the exact clipboard
+  replacement. Cancel leaves the clipboard unchanged.
+- **Share clipboard and uppercase it** first asks before reading the clipboard.
+  The host previews the captured text and requires a second confirmation to
+  share it with the plugin. The transformed output needs a separate copy
+  confirmation. Clipboard changes after preview do not change the shared
+  snapshot.
+
+Use only synthetic clipboard text. Do not use account data or real secrets.
+The fixture does not require a persistent grant or any network destination.
+A different plugin that also has network permission could send shared text
+through its granted capabilities; reading text does not approve a new origin.
+
+Blur/lock/close the owner window, cancel, revoke access, or disable the plugin
+to end a pending request. Late/duplicate replies cannot commit an old action.
+Only the focused unlocked main window is supported in this first slice. Other
+windows return unavailable instead of inheriting the request's authority.

examples/plugins/host-interactions/browser.js

@@ -0,0 +1,21 @@
+import { definePlugin, PLUGIN_HOST_INTERACTION_FEATURE } from '@netcatty/plugin-sdk';
+
+export default definePlugin({
+  activate(context) {
+    context.subscriptions.add(context.commands.registerCommand('com.netcatty.host-interactions.text', async () => {
+      if (!context.enabledFeatures.has(PLUGIN_HOST_INTERACTION_FEATURE)) throw new Error('Host interactions are unavailable');
+      const source = await context.ui.quickPick('Choose a text workflow', [
+        { id: 'compose', label: 'Compose synthetic text', description: 'Edit a draft, then explicitly confirm clipboard replacement.' },
+        { id: 'share', label: 'Share clipboard and uppercase it', description: 'Preview text, confirm sharing, then confirm the transformed copy.' },
+      ]);
+      if (source === undefined) return { cancelled: true };
+      const text = source === 'compose'
+        ? await context.ui.input('Edit synthetic text', 'synthetic text')
+        : await context.clipboard.readText('Share clipboard text for uppercase conversion');
+      if (text === undefined) return { cancelled: true };
+      const output = source === 'share' ? text.toUpperCase() : text;
+      const copied = await context.clipboard.writeText(output, 'Confirm the exact text to copy');
+      return { copied, characters: output.length };
+    }));
+  },
+});

examples/plugins/host-interactions/netcatty.plugin.json

@@ -0,0 +1,52 @@
+{
+  "manifestVersion": 1,
+  "id": "com.netcatty.host-interactions",
+  "name": "host-interactions",
+  "displayName": "Host text interactions",
+  "description": "Synthetic host choice, input and explicit clipboard sharing workflow.",
+  "version": "0.1.1",
+  "publisher": "netcatty",
+  "license": "GPL-3.0-or-later",
+  "engines": {
+    "netcatty": ">=0.0.0",
+    "api": ">=0.1.0-internal <0.2.0"
+  },
+  "features": {
+    "required": [
+      "host.interactions",
+      "commands.interactive"
+    ]
+  },
+  "main": {
+    "browser": "browser.js"
+  },
+  "activationEvents": [
+    "onCommand:com.netcatty.host-interactions.text"
+  ],
+  "permissions": {
+    "required": [
+      "commands",
+      "menus"
+    ],
+    "optional": [
+      "ui.interact",
+      "clipboard.read",
+      "clipboard.write"
+    ]
+  },
+  "contributes": {
+    "commands": [
+      {
+        "id": "com.netcatty.host-interactions.text",
+        "title": "Host text workflow",
+        "interactive": true
+      }
+    ],
+    "menus": [
+      {
+        "command": "com.netcatty.host-interactions.text",
+        "location": "commandPalette"
+      }
+    ]
+  }
+}

global.d.ts

@@ -444,6 +444,9 @@ declare global {
     listPluginCatalog?(): Promise<NetcattyPluginCatalogSnapshot>;
     getPluginCatalogReadme?(id: string, selectionToken?: string): Promise<string>;
     installCatalogPlugin?(id: string, selectionToken?: string): Promise<NetcattyInstalledPlugin>;
+    setPluginInteractionReady?(ready: boolean): Promise<boolean>;
+    respondPluginInteraction?(response: import("@netcatty/plugin-contract").HostInteractionResponse): Promise<boolean>;
+    onPluginInteraction?(callback: (event: import("@netcatty/plugin-contract").HostInteractionEvent) => void): () => void;
     listPlugins?(): Promise<NetcattyInstalledPlugin[]>;
     getPluginPermissions?(pluginId: string): Promise<NetcattyPluginPermissionSnapshot>;
     revokePluginPermissions?(pluginId: string): Promise<NetcattyInstalledPlugin>;

packages/plugin-cli/src/interactiveCommands.test.ts

@@ -0,0 +1,15 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { readFile } from 'node:fs/promises';
+import { validateManifestValue } from './manifest.js';
+import { checkPluginCompatibility } from './compatibility.js';
+
+const manifest = JSON.parse(await readFile(new URL('../../../examples/plugins/host-interactions/netcatty.plugin.json', import.meta.url), 'utf8'));
+test('interactive command budget requires feature negotiation without changing ordinary command admission', () => {
+  assert.equal(validateManifestValue(manifest).valid, true);
+  assert.equal(validateManifestValue({ ...manifest, features: { required: ['host.interactions'] } }).valid, false);
+  assert.equal(checkPluginCompatibility(manifest, { netcattyVersion: '1.0.0', features: ['host.interactions'] }).compatible, false);
+  assert.equal(checkPluginCompatibility(manifest, { netcattyVersion: '1.0.0', features: ['host.interactions', 'commands.interactive'] }).compatible, true);
+  const legacy = structuredClone(manifest); delete legacy.contributes.commands[0].interactive; legacy.features.required = ['host.interactions'];
+  assert.equal(validateManifestValue(legacy).valid, true);
+});

packages/plugin-cli/src/manifest.ts

@@ -367,6 +367,8 @@ function validateSemantics(manifest: PluginManifest): string[] {
   }
 
   const requiredFeatures = new Set(manifest.features?.required ?? []);
+  if (manifest.contributes?.commands?.some((command) => command.interactive)
+    && !requiredFeatures.has('commands.interactive')) errors.push('Interactive commands require commands.interactive');
   if (manifest.icon) {
     if (!requiredFeatures.has('metadata.brand-icon')) errors.push('Brand icons require metadata.brand-icon');
     if (!validRange(manifest.engines.api) || !satisfies('0.1.0-internal.1', manifest.engines.api) || satisfies('0.1.0-internal', manifest.engines.api)) errors.push('Brand icons require API >=0.1.0-internal.1 excluding the legacy revision');

packages/plugin-contract/schema/plugin-contract.schema.json

@@ -178,6 +178,311 @@
       },
       "additionalProperties": false
     },
+    "HostInteractionLimits": {
+      "const": {
+        "textBytes": 4096,
+        "requestBytes": 65536,
+        "items": 100,
+        "pendingPerRuntime": 1,
+        "pendingTotal": 8,
+        "requestsPerMinute": 10,
+        "timeoutMs": 60000
+      }
+    },
+    "HostInteractionFeature": {
+      "const": "host.interactions"
+    },
+    "InteractiveCommandFeature": {
+      "const": "commands.interactive"
+    },
+    "InteractiveCommandLimits": {
+      "const": { "timeoutMs": 180000 }
+    },
+    "HostQuickPickItem": {
+      "type": "object",
+      "required": [
+        "id",
+        "label"
+      ],
+      "properties": {
+        "id": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128
+        },
+        "label": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 512
+        },
+        "description": {
+          "type": "string",
+          "maxLength": 512
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostQuickPickRequest": {
+      "type": "object",
+      "required": [
+        "kind",
+        "title",
+        "items"
+      ],
+      "properties": {
+        "kind": {
+          "const": "quickPick"
+        },
+        "title": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128,
+          "pattern": "^[^\\u0000-\\u001f\\u007f]*$"
+        },
+        "items": {
+          "type": "array",
+          "minItems": 1,
+          "maxItems": 100,
+          "items": {
+            "$ref": "#/$defs/HostQuickPickItem"
+          }
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostSingleLineInputText": {
+      "description": "Single-line host input. CR and LF are rejected before display and on submission; clipboard text remains multiline.",
+      "type": "string",
+      "maxLength": 4096,
+      "pattern": "^[^\\u0000\\r\\n]*$"
+    },
+    "HostInputRequest": {
+      "type": "object",
+      "required": [
+        "kind",
+        "title"
+      ],
+      "properties": {
+        "kind": {
+          "const": "input"
+        },
+        "title": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128,
+          "pattern": "^[^\\u0000-\\u001f\\u007f]*$"
+        },
+        "initialValue": { "$ref": "#/$defs/HostSingleLineInputText" }
+      },
+      "additionalProperties": false
+    },
+    "HostClipboardReadRequest": {
+      "type": "object",
+      "required": [
+        "kind",
+        "title"
+      ],
+      "properties": {
+        "kind": {
+          "const": "clipboard.read"
+        },
+        "title": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128,
+          "pattern": "^[^\\u0000-\\u001f\\u007f]*$"
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostClipboardWriteRequest": {
+      "type": "object",
+      "required": [
+        "kind",
+        "title",
+        "text"
+      ],
+      "properties": {
+        "kind": {
+          "const": "clipboard.write"
+        },
+        "title": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128,
+          "pattern": "^[^\\u0000-\\u001f\\u007f]*$"
+        },
+        "text": {
+          "type": "string",
+          "maxLength": 4096,
+          "pattern": "^[^\\u0000]*$"
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostInteractionRequest": {
+      "oneOf": [
+        {
+          "$ref": "#/$defs/HostQuickPickRequest"
+        },
+        {
+          "$ref": "#/$defs/HostInputRequest"
+        },
+        {
+          "$ref": "#/$defs/HostClipboardReadRequest"
+        },
+        {
+          "$ref": "#/$defs/HostClipboardWriteRequest"
+        }
+      ]
+    },
+    "HostInteractionResult": {
+      "oneOf": [
+        {
+          "type": "object",
+          "required": [
+            "cancelled"
+          ],
+          "properties": {
+            "cancelled": {
+              "const": true
+            }
+          },
+          "additionalProperties": false
+        },
+        {
+          "type": "object",
+          "required": [
+            "cancelled",
+            "value"
+          ],
+          "properties": {
+            "cancelled": {
+              "const": false
+            },
+            "value": {
+              "oneOf": [
+                {
+                  "type": "string",
+                  "maxLength": 4096,
+                  "pattern": "^[^\\u0000]*$"
+                },
+                {
+                  "const": true
+                }
+              ]
+            }
+          },
+          "additionalProperties": false
+        }
+      ]
+    },
+    "HostInteractionResponse": {
+      "type": "object",
+      "required": [
+        "requestId",
+        "actionToken",
+        "action"
+      ],
+      "properties": {
+        "requestId": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128
+        },
+        "actionToken": {
+          "type": "string",
+          "minLength": 32,
+          "maxLength": 256
+        },
+        "action": {
+          "enum": [
+            "cancel",
+            "preview",
+            "submit"
+          ]
+        },
+        "value": {
+          "type": "string",
+          "maxLength": 4096,
+          "pattern": "^[^\\u0000]*$"
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostInteractionClosed": {
+      "type": "object",
+      "required": [
+        "requestId",
+        "closed"
+      ],
+      "properties": {
+        "requestId": {
+          "type": "string",
+          "maxLength": 128
+        },
+        "closed": {
+          "const": true
+        }
+      },
+      "additionalProperties": false
+    },
+    "HostInteractionEvent": {
+      "oneOf": [
+        {
+          "$ref": "#/$defs/HostInteractionPrompt"
+        },
+        {
+          "$ref": "#/$defs/HostInteractionClosed"
+        }
+      ]
+    },
+    "HostInteractionPrompt": {
+      "type": "object",
+      "required": [
+        "requestId",
+        "actionToken",
+        "pluginId",
+        "pluginVersion",
+        "expiresAt",
+        "phase",
+        "request"
+      ],
+      "properties": {
+        "requestId": {
+          "type": "string",
+          "maxLength": 128
+        },
+        "actionToken": {
+          "type": "string",
+          "maxLength": 256
+        },
+        "pluginId": {
+          "$ref": "#/$defs/PluginId"
+        },
+        "pluginVersion": {
+          "$ref": "#/$defs/SemanticVersion"
+        },
+        "expiresAt": {
+          "$ref": "#/$defs/SafePositiveInteger"
+        },
+        "phase": {
+          "enum": [
+            "request",
+            "preview"
+          ]
+        },
+        "request": {
+          "$ref": "#/$defs/HostInteractionRequest"
+        },
+        "previewText": {
+          "type": "string",
+          "maxLength": 4096,
+          "pattern": "^[^\\u0000]*$"
+        }
+      },
+      "additionalProperties": false
+    },
     "NetworkCredentialLeaseFeature": {
       "const": "network.credential-lease"
     },
@@ -335,6 +640,7 @@
         "commands",
         "menus",
         "views",
+        "ui.interact",
         "clipboard.read",
         "clipboard.write",
         "terminal.metadata",
@@ -372,6 +678,7 @@
         "commands",
         "menus",
         "views",
+        "ui.interact",
         "clipboard.read",
         "clipboard.write",
         "terminal.metadata",
@@ -648,7 +955,8 @@
         "category": { "$ref": "#/$defs/LocalizedText" },
         "description": { "$ref": "#/$defs/LocalizedText" },
         "icon": { "$ref": "#/$defs/IconReference" },
-        "enablement": { "$ref": "#/$defs/ContextKeyExpression" }
+        "enablement": { "$ref": "#/$defs/ContextKeyExpression" },
+        "interactive": { "type": "boolean", "default": false, "description": "Require commands.interactive for this command's fixed bounded host interaction budget. Does not grant UI or clipboard permissions." }
       },
       "additionalProperties": false
     },

packages/plugin-contract/src/generated/plugin-contract-limits.ts

@@ -6,6 +6,7 @@ export const PLUGIN_JSON_MAX_DEPTH = 128 as const;
 export const PLUGIN_JSON_MAX_NODES = 100000 as const;
 export const PLUGIN_WIRE_MAX_SAFE_INTEGER = 9007199254740991 as const;
 export const PLUGIN_RPC_MAX_JSON_BYTES = 1048576 as const;
+export const PLUGIN_HOST_INTERACTION_LIMITS = {"textBytes":4096,"requestBytes":65536,"items":100,"pendingPerRuntime":1,"pendingTotal":8,"requestsPerMinute":10,"timeoutMs":60000} as const;
 export const PLUGIN_RPC_ERROR_CODES = [-32700,-32600,-32601,-32602,-32603,-32001,-32002,-32003,-32004,-32005,-32006,-32007,-32008,-32009,-32010,-32011,-32012,-32013,-32014,-32015,-32016] as const;
 export const PLUGIN_STREAM_MAX_ID_LENGTH = 128 as const;
 export const PLUGIN_STREAM_MAX_CHUNK_BYTES = 16777216 as const;

packages/plugin-contract/src/generated/plugin-contract.ts

@@ -80,6 +80,7 @@ export type CommandContribution = {
   description?: LocalizedText;
   icon?: IconReference;
   enablement?: ContextKeyExpression;
+  interactive?: boolean;
 };
 
 export type CompanionExecutable = {
@@ -167,6 +168,75 @@ export type CredentialRef = {
 
 export type FeatureId = string;
 
+export type HostClipboardReadRequest = {
+  kind: "clipboard.read";
+  title: string;
+};
+
+export type HostClipboardWriteRequest = {
+  kind: "clipboard.write";
+  title: string;
+  text: string;
+};
+
+export type HostInputRequest = {
+  kind: "input";
+  title: string;
+  initialValue?: HostSingleLineInputText;
+};
+
+export type HostInteractionClosed = {
+  requestId: string;
+  closed: true;
+};
+
+export type HostInteractionEvent = (HostInteractionPrompt) | (HostInteractionClosed);
+
+export type HostInteractionFeature = "host.interactions";
+
+export type HostInteractionLimits = {"textBytes":4096,"requestBytes":65536,"items":100,"pendingPerRuntime":1,"pendingTotal":8,"requestsPerMinute":10,"timeoutMs":60000};
+
+export type HostInteractionPrompt = {
+  requestId: string;
+  actionToken: string;
+  pluginId: PluginId;
+  pluginVersion: SemanticVersion;
+  expiresAt: SafePositiveInteger;
+  phase: "request" | "preview";
+  request: HostInteractionRequest;
+  previewText?: string;
+};
+
+export type HostInteractionRequest = (HostQuickPickRequest) | (HostInputRequest) | (HostClipboardReadRequest) | (HostClipboardWriteRequest);
+
+export type HostInteractionResponse = {
+  requestId: string;
+  actionToken: string;
+  action: "cancel" | "preview" | "submit";
+  value?: string;
+};
+
+export type HostInteractionResult = ({
+  cancelled: true;
+}) | ({
+  cancelled: false;
+  value: (string) | (true);
+});
+
+export type HostQuickPickItem = {
+  id: string;
+  label: string;
+  description?: string;
+};
+
+export type HostQuickPickRequest = {
+  kind: "quickPick";
+  title: string;
+  items: Array<HostQuickPickItem>;
+};
+
+export type HostSingleLineInputText = string;
+
 export type IconReference = (ThemeIcon) | (PackageIcon);
 
 export type ImporterDetectPayload = {
@@ -319,6 +389,10 @@ export type ImporterSnippetDraft = {
   description?: string;
 };
 
+export type InteractiveCommandFeature = "commands.interactive";
+
+export type InteractiveCommandLimits = {"timeoutMs":180000};
+
 export type JsonPrimitive = (string) | (number) | (boolean) | (null);
 
 export type JsonRpcStandardErrorCode = -32700 | -32600 | -32601 | -32602 | -32603;
@@ -357,7 +431,7 @@ export type MenuLocation = "commandPalette" | "application" | "host/context" | "
 
 export type NetworkCredentialLeaseFeature = "network.credential-lease";
 
-export type NonResourceScopedPermission = "storage" | "runtime.advanced" | "settings.read" | "settings.write" | "commands" | "menus" | "views" | "clipboard.read" | "clipboard.write" | "terminal.metadata" | "terminal.output" | "terminal.input" | "terminal.decorate" | "terminal.complete" | "terminal.intercept.input" | "terminal.intercept.output" | "vault.metadata" | "vault.write" | "vault.credentials" | "sftp.read" | "sftp.write" | "secrets" | "provider.terminal" | "provider.connection" | "provider.authentication" | "provider.sync" | "provider.importer";
+export type NonResourceScopedPermission = "storage" | "runtime.advanced" | "settings.read" | "settings.write" | "commands" | "menus" | "views" | "ui.interact" | "clipboard.read" | "clipboard.write" | "terminal.metadata" | "terminal.output" | "terminal.input" | "terminal.decorate" | "terminal.complete" | "terminal.intercept.input" | "terminal.intercept.output" | "vault.metadata" | "vault.write" | "vault.credentials" | "sftp.read" | "sftp.write" | "secrets" | "provider.terminal" | "provider.connection" | "provider.authentication" | "provider.sync" | "provider.importer";
 
 export type NullableRpcId = (RpcId) | (null);
 
@@ -511,7 +585,7 @@ export type PluginNetworkResponse = {
   };
 };
 
-export type PluginPermission = "storage" | "runtime.advanced" | "settings.read" | "settings.write" | "commands" | "menus" | "views" | "clipboard.read" | "clipboard.write" | "terminal.metadata" | "terminal.output" | "terminal.input" | "terminal.decorate" | "terminal.complete" | "terminal.intercept.input" | "terminal.intercept.output" | "vault.metadata" | "vault.write" | "vault.credentials" | "sftp.read" | "sftp.write" | "network" | "filesystem.read" | "filesystem.write" | "secrets" | "companion.execute" | "provider.terminal" | "provider.connection" | "provider.authentication" | "provider.sync" | "provider.importer";
+export type PluginPermission = "storage" | "runtime.advanced" | "settings.read" | "settings.write" | "commands" | "menus" | "views" | "ui.interact" | "clipboard.read" | "clipboard.write" | "terminal.metadata" | "terminal.output" | "terminal.input" | "terminal.decorate" | "terminal.complete" | "terminal.intercept.input" | "terminal.intercept.output" | "vault.metadata" | "vault.write" | "vault.credentials" | "sftp.read" | "sftp.write" | "network" | "filesystem.read" | "filesystem.write" | "secrets" | "companion.execute" | "provider.terminal" | "provider.connection" | "provider.authentication" | "provider.sync" | "provider.importer";
 
 export type PluginWireErrorCode = -32001 | -32002 | -32003 | -32004 | -32005 | -32006 | -32007 | -32008 | -32009 | -32010 | -32011 | -32012 | -32013 | -32014 | -32015 | -32016;
 

packages/plugin-contract/src/index.ts

@@ -10,6 +10,7 @@ export {
   serializeJsonValue,
 } from "./jsonValue.js";
 export {
+  PLUGIN_HOST_INTERACTION_LIMITS,
   PLUGIN_IMPORTER_MAX_INPUT_BYTES,
   PLUGIN_IMPORTER_MAX_OUTPUT_BYTES,
   PLUGIN_IMPORTER_MAX_RECORD_BYTES,
@@ -51,3 +52,7 @@ export {
 export { inspectPluginBrandIcon, PLUGIN_BRAND_ICON_FEATURE, PLUGIN_BRAND_ICON_MAX_BYTES, PLUGIN_BRAND_ICON_MAX_EDGE } from './brandIcon.js';
 
 export const PLUGIN_NETWORK_CREDENTIAL_LEASE_FEATURE = "network.credential-lease" as const satisfies import("./generated/plugin-contract.js").NetworkCredentialLeaseFeature;
+
+export const PLUGIN_HOST_INTERACTION_FEATURE = "host.interactions" as const satisfies import("./generated/plugin-contract.js").HostInteractionFeature;
+
+export const PLUGIN_INTERACTIVE_COMMAND_FEATURE = "commands.interactive" as const satisfies import("./generated/plugin-contract.js").InteractiveCommandFeature;

packages/plugin-sdk/src/index.test.ts

@@ -413,3 +413,19 @@ test("network requests expose canonical host-consumed credential leases without
     void network.request({ url: 'https://example.invalid', authorization: { scheme: 'Digest' } });
   `);
 });
+
+test("host interaction SDK exposes bounded choice/input and explicit clipboard methods", () => {
+  assertSdkTypeChecks(`
+    import type { PluginContext } from './index.ts';
+    declare const context: PluginContext;
+    const choice: Promise<string | undefined> = context.ui.quickPick('Pick', [{ id: 'one', label: 'One' }]);
+    const input: Promise<string | undefined> = context.ui.input('Input', 'synthetic');
+    const text: Promise<string | undefined> = context.clipboard.readText('Share');
+    const copied: Promise<boolean> = context.clipboard.writeText('synthetic', 'Copy');
+    void [choice, input, text, copied];
+    // @ts-expect-error A plugin boolean cannot grant clipboard authority.
+    context.clipboard.readText('Share', { userGesture: true });
+    // @ts-expect-error No ambient clipboard watcher exists.
+    context.clipboard.watch(() => {});
+  `);
+});

packages/plugin-sdk/src/index.ts

@@ -109,6 +109,19 @@ export interface PluginCommands {
   executeCommand<T extends JsonValue = JsonValue>(commandId: string, args?: JsonValue): Promise<T>;
 }
 
+export interface PluginHostUI {
+  quickPick(title: string, items: readonly import("@netcatty/plugin-contract").HostQuickPickItem[]): Promise<string | undefined>;
+  /** Single-line text. The host rejects CR/LF in initial values and submitted responses. */
+  input(title: string, initialValue?: string): Promise<string | undefined>;
+}
+
+export interface PluginClipboard {
+  /** The host previews text only after the user asks, then separately confirms sharing it. */
+  readText(title: string): Promise<string | undefined>;
+  /** The host shows the exact text and requires explicit confirmation before replacement. */
+  writeText(text: string, title: string): Promise<boolean>;
+}
+
 export interface PluginContextKeys {
   set(key: string, value: JsonValue): Promise<void>;
 }
@@ -723,6 +736,8 @@ export interface PluginContext {
   readonly storage: PluginKeyValueStore;
   readonly settings: PluginSettings;
   readonly commands: PluginCommands;
+  readonly ui: PluginHostUI;
+  readonly clipboard: PluginClipboard;
   readonly contextKeys: PluginContextKeys;
   readonly views: PluginViews;
   readonly providers: PluginProviders;
@@ -913,3 +928,6 @@ export function throwIfCancellationRequested(token: CancellationToken): void {
 }
 
 export { PLUGIN_NETWORK_CREDENTIAL_LEASE_FEATURE } from "@netcatty/plugin-contract";
+
+export { PLUGIN_HOST_INTERACTION_FEATURE } from "@netcatty/plugin-contract";
+export { PLUGIN_INTERACTIVE_COMMAND_FEATURE } from "@netcatty/plugin-contract";

scripts/generate-plugin-contract.mjs

@@ -305,6 +305,11 @@ function schemaTypeToTs(node, level = 0) {
   return "unknown";
 }
 
+const hostInteractionLimits = schema.$defs.HostInteractionLimits?.const;
+if (!hostInteractionLimits || Object.values(hostInteractionLimits).some((value) => !Number.isSafeInteger(value) || value < 1)) {
+  throw new Error("HostInteractionLimits must contain positive bounded integers");
+}
+
 const definitionNames = Object.keys(schema.$defs).sort((left, right) =>
   left.localeCompare(right, "en"),
 );
@@ -327,6 +332,7 @@ const generatedLimits = [
   `export const PLUGIN_JSON_MAX_NODES = ${jsonValueLimits.maxNodes} as const;`,
   `export const PLUGIN_WIRE_MAX_SAFE_INTEGER = ${wireIntegerLimits.maxSafeInteger} as const;`,
   `export const PLUGIN_RPC_MAX_JSON_BYTES = ${rpcLimits.maxJsonBytes} as const;`,
+  `export const PLUGIN_HOST_INTERACTION_LIMITS = ${JSON.stringify(hostInteractionLimits)} as const;`,
   `export const PLUGIN_RPC_ERROR_CODES = ${JSON.stringify(rpcErrorCodes)} as const;`,
   `export const PLUGIN_STREAM_MAX_ID_LENGTH = ${streamLimits.maxStreamIdLength} as const;`,
   `export const PLUGIN_STREAM_MAX_CHUNK_BYTES = ${streamLimits.maxChunkBytes} as const;`,