diff --git a/apps/desktop-shell/scripts/check-config.mjs b/apps/desktop-shell/scripts/check-config.mjs
index 92bf5ed59..03076fac1 100644
--- a/apps/desktop-shell/scripts/check-config.mjs
+++ b/apps/desktop-shell/scripts/check-config.mjs
@@ -705,6 +705,12 @@ const requiredMainSnippets = [
   'DownloadEvent::Requested { .. } => false',
   '.on_download(|_webview, event| should_allow_desktop_webview_download(&event))',
   'NewWindowResponse::Deny',
+  'HOST_BRIDGE_METHODS',
+  'HOST_BRIDGE_REQUEST_ID_MAX_LENGTH',
+  'normalize_request_id',
+  'is_host_bridge_method',
+  'invalid host bridge request id',
+  'invalid host bridge method',
   'HostBridgeReplayState',
   'HostBridgeReplayReservation',
   'HOST_BRIDGE_RESPONSE_CACHE_MAX',
diff --git a/apps/desktop-shell/src-tauri/src/main.rs b/apps/desktop-shell/src-tauri/src/main.rs
index 43b76172f..2f3a1afeb 100644
--- a/apps/desktop-shell/src-tauri/src/main.rs
+++ b/apps/desktop-shell/src-tauri/src/main.rs
@@ -24,6 +24,31 @@ use tauri_plugin_opener::OpenerExt;
 
 const HOST_BRIDGE_PROTOCOL: &str = "GenarrativeHostBridge";
 const HOST_BRIDGE_VERSION: u8 = 1;
+const HOST_BRIDGE_METHODS: [&str; 23] = [
+    "host.getRuntime",
+    "appearance.getColorScheme",
+    "auth.requestLogin",
+    "payment.request",
+    "share.setTarget",
+    "share.open",
+    "navigation.openNativePage",
+    "app.reloadWebView",
+    "app.openExternalUrl",
+    "app.setTitle",
+    "app.setBadgeCount",
+    "network.status",
+    "clipboard.writeText",
+    "clipboard.readText",
+    "file.exportText",
+    "file.importText",
+    "file.exportImage",
+    "file.importImage",
+    "file.captureImage",
+    "file.importAudio",
+    "file.exportAudio",
+    "haptics.impact",
+    "notification.showLocal",
+];
 const WEB_APP_ORIGIN: &str = "https://app.genarrative.world";
 const EXTERNAL_URL_PROTOCOLS: [&str; 4] = ["http:", "https:", "mailto:", "tel:"];
 const EXPORT_TEXT_MAX_BYTES: usize = 5 * 1024 * 1024;
@@ -39,6 +64,7 @@ const DESKTOP_NETWORK_CHECK_TIMEOUT_MS: u64 = 1200;
 const LOCAL_NOTIFICATION_TITLE_MAX_LENGTH: usize = 80;
 const LOCAL_NOTIFICATION_BODY_MAX_LENGTH: usize = 240;
 const CLIPBOARD_TEXT_MAX_LENGTH: usize = 100000;
+const HOST_BRIDGE_REQUEST_ID_MAX_LENGTH: usize = 120;
 const HOST_BRIDGE_RESPONSE_CACHE_MAX: usize = 128;
 const DESKTOP_TRAY_ID: &str = "genarrative-desktop-tray";
 const TRAY_MENU_SHOW: &str = "show-main-window";
@@ -296,15 +322,54 @@ fn color_scheme_from_theme(theme: Theme) -> &'static str {
     }
 }
 
+fn has_control_character(value: &str) -> bool {
+    value.chars().any(|character| {
+        let code_point = character as u32;
+        code_point <= 31 || code_point == 127
+    })
+}
+
+fn normalize_request_id(raw_id: &str) -> Option<String> {
+    let id = raw_id.trim();
+    if id.is_empty()
+        || id.chars().count() > HOST_BRIDGE_REQUEST_ID_MAX_LENGTH
+        || has_control_character(id)
+    {
+        return None;
+    }
+
+    Some(id.to_string())
+}
+
+fn is_host_bridge_method(method: &str) -> bool {
+    HOST_BRIDGE_METHODS.contains(&method)
+}
+
 fn validate_request(request: &HostBridgeRequest) -> Option<HostBridgeResponse> {
+    let Some(request_id) = normalize_request_id(&request.id) else {
+        return Some(failed(
+            "invalid".to_string(),
+            "invalid_request",
+            "invalid host bridge request id",
+        ));
+    };
+
     if request.bridge != HOST_BRIDGE_PROTOCOL || request.version != HOST_BRIDGE_VERSION {
         return Some(failed(
-            request.id.clone(),
+            request_id,
             "invalid_request",
             "invalid host bridge envelope",
         ));
     }
 
+    if !is_host_bridge_method(&request.method) {
+        return Some(failed(
+            request_id,
+            "invalid_request",
+            "invalid host bridge method",
+        ));
+    }
+
     None
 }
 
@@ -1676,11 +1741,12 @@ async fn execute_host_bridge_request(
 async fn host_bridge_request(
     app: tauri::AppHandle,
     replay_state: tauri::State<'_, HostBridgeReplayState>,
-    request: HostBridgeRequest,
+    mut request: HostBridgeRequest,
 ) -> Result<HostBridgeResponse, String> {
     if let Some(response) = validate_request(&request) {
         return Ok(response);
     }
+    request.id = normalize_request_id(&request.id).unwrap_or(request.id);
 
     let response = match replay_state.reserve(&request.id) {
         HostBridgeReplayReservation::Wait(slot) => HostBridgeReplayState::wait_for_response(slot),
@@ -1903,6 +1969,38 @@ mod tests {
         assert_eq!(response.error.expect("error").code, "invalid_request");
     }
 
+    #[test]
+    fn invalid_request_id_and_unknown_method_are_rejected() {
+        for id in ["", "request\n1"] {
+            let mut invalid = request("share.open");
+            invalid.id = id.to_string();
+
+            let response = resolve_host_bridge_request(invalid);
+
+            assert!(!response.ok);
+            assert_eq!(response.id, "invalid");
+            assert_eq!(response.error.expect("error").code, "invalid_request");
+        }
+
+        let mut oversized = request("share.open");
+        oversized.id = "a".repeat(HOST_BRIDGE_REQUEST_ID_MAX_LENGTH + 1);
+        let response = resolve_host_bridge_request(oversized);
+        assert!(!response.ok);
+        assert_eq!(response.id, "invalid");
+        assert_eq!(response.error.expect("error").code, "invalid_request");
+
+        let mut multibyte_boundary = request("host.getRuntime");
+        multibyte_boundary.id = "作".repeat(HOST_BRIDGE_REQUEST_ID_MAX_LENGTH);
+        let response = resolve_host_bridge_request(multibyte_boundary);
+        assert!(response.ok);
+
+        let response = resolve_host_bridge_request(request("host.runArbitraryCommand"));
+        assert!(!response.ok);
+        let error = response.error.expect("error");
+        assert_eq!(error.code, "invalid_request");
+        assert_eq!(error.message, "invalid host bridge method");
+    }
+
     #[test]
     fn host_bridge_replay_state_reuses_first_response_for_duplicate_id() {
         let replay_state = HostBridgeReplayState::default();
diff --git a/apps/mobile-shell/scripts/check-config.mjs b/apps/mobile-shell/scripts/check-config.mjs
index dfeee5c73..7ea7d8410 100644
--- a/apps/mobile-shell/scripts/check-config.mjs
+++ b/apps/mobile-shell/scripts/check-config.mjs
@@ -649,6 +649,8 @@ for (const snippet of [
   'normalizeHostBridgeExportFileName',
   'normalizeHostBridgeClipboardText',
   'base64Data',
+  'isHostBridgeMethod',
+  'normalizeHostBridgeRequestId',
   'HOST_BRIDGE_RESPONSE_CACHE_MAX',
   'completedHostBridgeResponses',
   'inFlightHostBridgeResponses',
diff --git a/apps/mobile-shell/src/mobileHostBridge.test.ts b/apps/mobile-shell/src/mobileHostBridge.test.ts
index 0b4a3e341..53c4c3a5d 100644
--- a/apps/mobile-shell/src/mobileHostBridge.test.ts
+++ b/apps/mobile-shell/src/mobileHostBridge.test.ts
@@ -198,6 +198,21 @@ async function send(requestValue: HostBridgeRequest) {
   return response;
 }
 
+async function sendRaw(requestValue: unknown) {
+  const responses: HostBridgeResponse[] = [];
+
+  await handleMobileHostBridgeMessage(JSON.stringify(requestValue), (response) =>
+    responses.push(response),
+  );
+
+  const response = responses[0];
+  if (!response) {
+    throw new Error('host bridge response missing');
+  }
+
+  return response;
+}
+
 function expectOk(response: HostBridgeResponse) {
   if (!response.ok) {
     throw new Error('expected ok host bridge response');
@@ -431,6 +446,31 @@ describe('handleMobileHostBridgeMessage', () => {
     },
   );
 
+  test('拒绝非法 request id 和未知 method', async () => {
+    const invalidId = await sendRaw({
+      bridge: HOST_BRIDGE_PROTOCOL,
+      version: HOST_BRIDGE_VERSION,
+      id: 'request\n1',
+      method: 'share.open',
+    });
+    const unknownMethod = await sendRaw({
+      bridge: HOST_BRIDGE_PROTOCOL,
+      version: HOST_BRIDGE_VERSION,
+      id: 'request-unknown',
+      method: 'host.runArbitraryCommand',
+    });
+
+    expect(expectFailed(invalidId).error).toEqual({
+      code: 'invalid_request',
+      message: 'invalid host bridge request',
+    });
+    expect(expectFailed(unknownMethod).error).toEqual({
+      code: 'invalid_request',
+      message: 'invalid host bridge request',
+    });
+    expect(Share.share).not.toHaveBeenCalled();
+  });
+
   test('app.reloadWebView 刷新移动壳当前 WebView', async () => {
     const reloadWebView = vi.fn();
     configureMobileHostBridgeNavigation({
diff --git a/apps/mobile-shell/src/mobileHostBridge.ts b/apps/mobile-shell/src/mobileHostBridge.ts
index ce00f2c25..7af479d35 100644
--- a/apps/mobile-shell/src/mobileHostBridge.ts
+++ b/apps/mobile-shell/src/mobileHostBridge.ts
@@ -37,12 +37,14 @@ import {
   type HostBridgeResponse,
   type HostBridgeTextMimeType,
   type NavigateNativePagePayload,
+  isHostBridgeMethod,
   normalizeHostBridgeBadgeCount,
   normalizeHostBridgeClipboardText,
   normalizeHostBridgeColorScheme,
   normalizeHostBridgeExportFileName,
   normalizeHostBridgeExternalUrl,
   normalizeHostBridgeLocalNotification,
+  normalizeHostBridgeRequestId,
   type OpenExternalUrlPayload,
   type SetBadgeCountPayload,
   type ShareOpenPayload,
@@ -204,11 +206,12 @@ function isHostBridgeRequest(value: unknown): value is HostBridgeRequest {
   }
 
   const candidate = value as Partial<HostBridgeRequest>;
+  const requestId = normalizeHostBridgeRequestId(candidate.id);
   return (
     candidate.bridge === HOST_BRIDGE_PROTOCOL &&
     candidate.version === HOST_BRIDGE_VERSION &&
-    typeof candidate.id === 'string' &&
-    typeof candidate.method === 'string'
+    requestId !== null &&
+    isHostBridgeMethod(candidate.method)
   );
 }
 
@@ -1040,6 +1043,7 @@ export async function handleMobileHostBridgeMessage(
     return;
   }
 
+  parsed.id = normalizeHostBridgeRequestId(parsed.id) ?? parsed.id;
   sendResponse(await resolveMobileHostBridgeResponse(parsed));
 }
 
diff --git a/docs/project-memory/shared-memory/decision-log.md b/docs/project-memory/shared-memory/decision-log.md
index 932829143..f7aaa6c09 100644
--- a/docs/project-memory/shared-memory/decision-log.md
+++ b/docs/project-memory/shared-memory/decision-log.md
@@ -68,6 +68,7 @@
 - 2026-06-18 桌面壳 DevTools 边界：Tauri 主 WebView 配置必须显式 `devtools=false`，Cargo 依赖不得启用 Tauri `devtools` feature；桌面壳本地调试走普通浏览器和 Vite，不把 debug / release 桌面包变成可打开浏览器检查器的调试容器。配置检查会拒绝主窗口 DevTools 或 release feature 被重新打开。
 - 2026-06-18 桌面壳 Tauri 命令白名单：桌面壳源码、Tauri build manifest、主窗口 capability 和本地自动生成权限目录都只能暴露 `host_bridge_request` 一个受控 command；所有桌面能力继续在 Rust 内部按 HostBridge method 白名单分发，不新增可被 H5 直接 `invoke` 的 Tauri command，也不授予插件 JS guest API。检查脚本会拒绝多余 command、权限列表顺序漂移和残留的自动生成权限文件。
 - 2026-06-18 HostBridge request id replay：Expo 和 Tauri 壳都必须按 request id 回放首次完成结果；同 id 进行中的请求共享同一执行结果，已完成请求直接回放缓存响应，避免系统分享、外链、剪贴板、文件选择 / 保存、本地通知、窗口导航等宿主副作用被重复触发。两端配置检查和测试会锁住 replay 结构。
+- 2026-06-18 HostBridge request envelope 校验：共享契约提供 `isHostBridgeMethod` 与 `normalizeHostBridgeRequestId`，Expo 壳直接复用，Tauri 壳镜像同一白名单和 id 规则；空 id、控制字符 id、超长 id 和未知 method 都必须在 replay / 能力分发前返回 `invalid_request`，已知但当前壳未实现的登录 / 支付等 method 才返回 `unsupported_method`。
 - 2026-06-18 桌面壳 CSP 分层：Tauri release `csp` 不得包含 `http://127.0.0.1:*`、`ws://127.0.0.1:*` 或其它本机调试源，本机 Vite、HMR WebSocket 和开发 frame 只允许出现在 `devCsp`。桌面壳配置检查会同时拒绝 release CSP 混入本机调试源、dev CSP 缺失本机开发源，以及 release / dev CSP 加入 `unsafe-eval`、`tauri:` 或 `file:`。
 - 2026-06-18 壳生产代码禁用临时替身：Expo 与 Tauri 壳的生产源码和配置不得出现 mock / fake / placeholder / stub / TODO / FIXME 以及对应中文脚手架词；测试文件仍可使用 mock。两端壳配置检查会扫描生产入口、配置和壳实现，根级 `npm run check:native-shells` 也会统一扫描两端壳生产源码，防止把临时替身、占位文案或伪实现带进可分发壳。
 - 2026-06-18 移动壳启动页与 adaptive icon：Expo 移动壳启动页和 Android adaptive icon 复用现有真实品牌图标 `apps/mobile-shell/assets/icon.png`，背景色固定为 H5 壳根背景 `#fffdf9`。该 PNG 是 1024x1024 RGBA 透明前景品牌资产，不新增占位图；配置检查会校验图标尺寸、透明像素、splash 和 adaptive icon 指向，避免后续换成非品牌或占位素材。
@@ -2392,6 +2393,13 @@
 - 影响范围：`apps/mobile-shell/src/mobileHostBridge.ts`、`apps/desktop-shell/src-tauri/src/main.rs`、两端配置检查、Expo / Tauri HostBridge 方案文档。
 - 验证方式：`npm run check:native-shells`、`npm run typecheck`、`npm run check:encoding`、`git diff --check`。
 
+## 2026-06-18 HostBridge request envelope 校验
+
+- 背景：HostBridge 请求来自 H5 WebView / Tauri 注入通道，TypeScript 类型不能替代宿主运行时校验；空 id、控制字符 id、过长 id 或未知 method 如果进入 replay / 能力分发，可能污染缓存、绕过方法白名单或造成错误语义混乱。
+- 决策：共享契约提供 `isHostBridgeMethod` 和 `normalizeHostBridgeRequestId`；Expo 壳直接复用，Tauri 壳镜像同一 `HOST_BRIDGE_METHODS` 和 request id 规则。request id 归一后必须为 1-120 字符且不含控制字符；未知 method 在进入能力分发前返回 `invalid_request`，只有白名单内但当前壳未实现的登录 / 支付等 method 返回 `unsupported_method`。
+- 影响范围：`packages/shared/src/contracts/hostBridge.ts`、`apps/mobile-shell/src/mobileHostBridge.ts`、`apps/desktop-shell/src-tauri/src/main.rs`、两端配置检查、Expo / Tauri HostBridge 方案文档。
+- 验证方式：`npm run check:native-shells`、`npm run typecheck`、`npm run check:encoding`、`git diff --check`。
+
 ## 2026-06-18 移动壳渠道 SDK 依赖收口
 
 - 背景：Expo 移动壳运行时依赖可能从根安装树解析；如果只检查 `apps/mobile-shell/package.json`，根 H5 包仍可能直接引入 Expo Updates、Sentry、Firebase Analytics、PostHog、Amplitude、Segment、CodePush 等移动端发布通道、崩溃上报或 analytics SDK，让壳边界绕过真实渠道契约。
diff --git a/docs/【前端架构】ExpoReactNative与Tauri宿主壳方案-2026-06-17.md b/docs/【前端架构】ExpoReactNative与Tauri宿主壳方案-2026-06-17.md
index 3bfb49f0c..ebe4da1c5 100644
--- a/docs/【前端架构】ExpoReactNative与Tauri宿主壳方案-2026-06-17.md
+++ b/docs/【前端架构】ExpoReactNative与Tauri宿主壳方案-2026-06-17.md
@@ -229,7 +229,7 @@ GameBridge 禁止：
 
 ## 安全约束
 
-- HostBridge request 必须校验 `bridge`、`version`、`id`、`method` 和 payload shape。
+- HostBridge request 必须校验 `bridge`、`version`、`id`、`method` 和 payload shape；`id` 归一后必须是 1-120 字符且不含控制字符，`method` 必须来自共享白名单，未知 method 作为非法 request 拒绝。
 - 壳层只接受来自允许 origin / packaged asset 的消息。
 - H5 侧 HostBridge listener 只接收原生壳注入到当前窗口的 message；带有非当前窗口 `source` 或非当前页面 `origin` 的消息必须忽略，避免 AI sandbox iframe 或其它子上下文伪造 HostBridge response / event。
 - 每个请求必须有超时，重复 `id` 不得重复执行支付、登录、系统分享、文件导入导出、本地通知等宿主副作用；Expo 和 Tauri 壳都必须按 request id 回放首次完成结果。
@@ -350,6 +350,8 @@ GameBridge 禁止：
 
 2026-06-18 追加：HostBridge request id 进入宿主侧 replay 门禁。Expo 壳会缓存已完成响应并让进行中的同 id 请求共用同一执行结果；Tauri 壳在唯一 `host_bridge_request` command 外层通过 `HostBridgeReplayState` 对同 id 请求做等待 / 回放。重复 id 只返回首次结果，不会二次触发系统分享、外链、剪贴板、文件选择 / 保存、本地通知或窗口动作。
 
+2026-06-18 追加：HostBridge request envelope 校验收紧。共享契约提供 `isHostBridgeMethod` 和 `normalizeHostBridgeRequestId`；Expo 壳直接复用，Tauri 壳镜像同一 method 白名单和 request id 规则。空 id、控制字符 id、超长 id 和未知 method 都在进入 replay / 能力分发前返回 `invalid_request`，已知但当前壳未实现的登录 / 支付等 method 才返回 `unsupported_method`。
+
 2026-06-18 追加：桌面壳 release CSP 与 dev CSP 分离。Release `csp` 不再包含 `http://127.0.0.1:*` 或 `ws://127.0.0.1:*`，只允许打包资产、自身脚本、生产 HTTPS / WSS API、图片、媒体和 sandbox frame 所需来源；本地 Vite、HMR WebSocket 和开发 frame 只写入 Tauri `devCsp`。`apps/desktop-shell/scripts/check-config.mjs` 会拒绝 release CSP 混入本机调试源，也会校验 dev CSP 仍保留本机开发源。
 
 2026-06-18 追加：桌面壳 release 构建烟测进入统一验收。`npm run check:native-shells` 会在 H5 HostBridge、Expo 壳和 Tauri 单测通过后执行 `npm run desktop-shell:build -- --no-bundle`，确认根 `dist` H5 资产、Tauri release 入口、受控命令白名单、图标和 Rust release 编译可以共同产出桌面二进制；该烟测不生成平台安装包，避免把 Linux 本机缺少的系统打包器误判为 HostBridge 回归。
diff --git a/packages/shared/src/contracts/hostBridge.test.ts b/packages/shared/src/contracts/hostBridge.test.ts
index fa90df065..20a9e8bd1 100644
--- a/packages/shared/src/contracts/hostBridge.test.ts
+++ b/packages/shared/src/contracts/hostBridge.test.ts
@@ -1,6 +1,7 @@
 import { describe, expect, test } from 'vitest';
 
 import {
+  isHostBridgeMethod,
   isHostBridgeCapability,
   normalizeHostBridgeBadgeCount,
   normalizeHostBridgeClipboardText,
@@ -10,6 +11,7 @@ import {
   normalizeHostBridgeExternalUrl,
   normalizeHostBridgeLifecycleState,
   normalizeHostBridgeLocalNotification,
+  normalizeHostBridgeRequestId,
 } from './hostBridge';
 
 describe('HostBridge shared contract helpers', () => {
@@ -51,6 +53,10 @@ describe('HostBridge shared contract helpers', () => {
   });
 
   test('识别 HostBridge 能力白名单', () => {
+    expect(isHostBridgeMethod('host.getRuntime')).toBe(true);
+    expect(isHostBridgeMethod('share.open')).toBe(true);
+    expect(isHostBridgeMethod('app.lifecycle')).toBe(false);
+    expect(isHostBridgeMethod('unknown.method')).toBe(false);
     expect(isHostBridgeCapability('appearance.getColorScheme')).toBe(true);
     expect(isHostBridgeCapability('share.open')).toBe(true);
     expect(isHostBridgeCapability('app.reloadWebView')).toBe(true);
@@ -71,6 +77,14 @@ describe('HostBridge shared contract helpers', () => {
     expect(isHostBridgeCapability(null)).toBe(false);
   });
 
+  test('归一化 HostBridge request id', () => {
+    expect(normalizeHostBridgeRequestId('  request-1  ')).toBe('request-1');
+    expect(normalizeHostBridgeRequestId('')).toBeNull();
+    expect(normalizeHostBridgeRequestId('request\n1')).toBeNull();
+    expect(normalizeHostBridgeRequestId('a'.repeat(121))).toBeNull();
+    expect(normalizeHostBridgeRequestId(null)).toBeNull();
+  });
+
   test('归一化宿主剪贴板读取文本', () => {
     expect(normalizeHostBridgeClipboardText('作品号 PZ-1')).toEqual({
       text: '作品号 PZ-1',
diff --git a/packages/shared/src/contracts/hostBridge.ts b/packages/shared/src/contracts/hostBridge.ts
index 2bb5eac33..460f52fa7 100644
--- a/packages/shared/src/contracts/hostBridge.ts
+++ b/packages/shared/src/contracts/hostBridge.ts
@@ -41,6 +41,13 @@ export const HOST_BRIDGE_METHODS = [
 
 export type HostBridgeMethod = (typeof HOST_BRIDGE_METHODS)[number];
 
+export function isHostBridgeMethod(value: unknown): value is HostBridgeMethod {
+  return (
+    typeof value === 'string' &&
+    HOST_BRIDGE_METHODS.includes(value as HostBridgeMethod)
+  );
+}
+
 export const HOST_BRIDGE_CAPABILITIES = [
   ...HOST_BRIDGE_METHODS,
   'host.events',
@@ -78,6 +85,25 @@ export type HostBridgeRequest<Payload = unknown> = {
   timeoutMs?: number;
 };
 
+export const HOST_BRIDGE_REQUEST_ID_MAX_LENGTH = 120;
+
+export function normalizeHostBridgeRequestId(rawId: unknown) {
+  if (typeof rawId !== 'string') {
+    return null;
+  }
+
+  const id = rawId.trim();
+  if (
+    !id ||
+    id.length > HOST_BRIDGE_REQUEST_ID_MAX_LENGTH ||
+    hasHostBridgeControlCharacter(id)
+  ) {
+    return null;
+  }
+
+  return id;
+}
+
 export type HostBridgeError = {
   code:
     | 'invalid_request'