diff --git a/web/src/lib/createClientTurnId.test.ts b/web/src/lib/createClientTurnId.test.ts
new file mode 100644
index 00000000..5d2e8b0a
--- /dev/null
+++ b/web/src/lib/createClientTurnId.test.ts
@@ -0,0 +1,65 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { createClientTurnId, isUuidV4 } from './createClientTurnId';
+
+const originalCrypto = globalThis.crypto;
+
+function restoreCrypto() {
+  Object.defineProperty(globalThis, 'crypto', {
+    configurable: true,
+    value: originalCrypto,
+  });
+}
+
+test('createClientTurnId uses randomUUID when available', () => {
+  Object.defineProperty(globalThis, 'crypto', {
+    configurable: true,
+    value: {
+      randomUUID: () => '11111111-1111-4111-8111-111111111111',
+    },
+  });
+
+  try {
+    assert.equal(createClientTurnId(), '11111111-1111-4111-8111-111111111111');
+  } finally {
+    restoreCrypto();
+  }
+});
+
+test('createClientTurnId falls back to getRandomValues UUID v4', () => {
+  Object.defineProperty(globalThis, 'crypto', {
+    configurable: true,
+    value: {
+      getRandomValues: (bytes: Uint8Array) => {
+        for (let i = 0; i < bytes.length; i += 1) {
+          bytes[i] = i;
+        }
+        return bytes;
+      },
+    },
+  });
+
+  try {
+    const id = createClientTurnId();
+    assert.equal(isUuidV4(id), true);
+    assert.match(id, /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i);
+  } finally {
+    restoreCrypto();
+  }
+});
+
+test('createClientTurnId throws when no secure random API exists', () => {
+  Object.defineProperty(globalThis, 'crypto', {
+    configurable: true,
+    value: {},
+  });
+
+  try {
+    assert.throws(
+      () => createClientTurnId(),
+      /当前浏览器不支持安全随机标识/
+    );
+  } finally {
+    restoreCrypto();
+  }
+});
diff --git a/web/src/lib/createClientTurnId.ts b/web/src/lib/createClientTurnId.ts
new file mode 100644
index 00000000..d719e39d
--- /dev/null
+++ b/web/src/lib/createClientTurnId.ts
@@ -0,0 +1,39 @@
+const UUID_V4_REGEX =
+  /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
+
+function formatUuidV4(bytes: Uint8Array): string {
+  bytes[6] = (bytes[6] & 0x0f) | 0x40;
+  bytes[8] = (bytes[8] & 0x3f) | 0x80;
+
+  const hex = Array.from(bytes, (value) => value.toString(16).padStart(2, '0'));
+
+  return [
+    hex.slice(0, 4).join(''),
+    hex.slice(4, 6).join(''),
+    hex.slice(6, 8).join(''),
+    hex.slice(8, 10).join(''),
+    hex.slice(10, 16).join(''),
+  ].join('-');
+}
+
+/**
+ * 生成客户端 turn 标识，兼容非 Secure Context（如局域网 HTTP）。
+ * 优先 randomUUID；否则用 getRandomValues 生成 RFC 4122 v4 UUID。
+ */
+export function createClientTurnId(): string {
+  if (typeof globalThis.crypto?.randomUUID === 'function') {
+    return globalThis.crypto.randomUUID();
+  }
+
+  if (typeof globalThis.crypto?.getRandomValues === 'function') {
+    const bytes = new Uint8Array(16);
+    globalThis.crypto.getRandomValues(bytes);
+    return formatUuidV4(bytes);
+  }
+
+  throw new Error('当前浏览器不支持安全随机标识，请升级浏览器或通过 HTTPS 访问');
+}
+
+export function isUuidV4(value: string): boolean {
+  return UUID_V4_REGEX.test(value);
+}
diff --git a/web/src/types/sendMessage.ts b/web/src/types/sendMessage.ts
new file mode 100644
index 00000000..86e44e09
--- /dev/null
+++ b/web/src/types/sendMessage.ts
@@ -0,0 +1,4 @@
+export type SendMessageResult = {
+  accepted: boolean;
+  error?: string;
+};