diff --git a/server-node/src/modules/story/storySpacetimeBridge.test.ts b/server-node/src/modules/story/storySpacetimeBridge.test.ts
new file mode 100644
index 00000000..e6167dcd
--- /dev/null
+++ b/server-node/src/modules/story/storySpacetimeBridge.test.ts
@@ -0,0 +1,248 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import type { Request } from 'express';
+
+import type { AppConfig } from '../../config.js';
+import {
+  authenticateRuntimeStoryViaSpacetime,
+  createRuntimeStorySnapshotRepository,
+  resetRuntimeStoryBridgeConnectorForTest,
+  setRuntimeStoryBridgeConnectorForTest,
+  shouldUseSpacetimeStoryAuth,
+} from './storySpacetimeBridge.js';
+
+function createTestConfig(): AppConfig {
+  return {
+    nodeEnv: 'test',
+    projectRoot: '/tmp/genarrative-test',
+    publicDir: '/tmp/genarrative-test/public',
+    logsDir: '/tmp/genarrative-test/logs',
+    dataDir: '/tmp/genarrative-test/data',
+    rawEnv: {},
+    databaseUrl: 'pg-mem://genarrative-test',
+    serverAddr: ':0',
+    logLevel: 'silent',
+    editorApiEnabled: true,
+    assetsApiEnabled: true,
+    jwtSecret: 'test-secret',
+    jwtExpiresIn: '7d',
+    jwtIssuer: 'genarrative-test',
+    llm: {
+      baseUrl: 'https://example.invalid',
+      apiKey: '',
+      model: 'test-model',
+    },
+    dashScope: {
+      baseUrl: 'https://example.invalid',
+      apiKey: '',
+      imageModel: 'test-image-model',
+      requestTimeoutMs: 1000,
+    },
+    smsAuth: {
+      enabled: true,
+      provider: 'mock',
+      endpoint: 'dypnsapi.aliyuncs.com',
+      accessKeyId: '',
+      accessKeySecret: '',
+      signName: 'Test Sign',
+      templateCode: '100001',
+      templateParamKey: 'code',
+      countryCode: '86',
+      schemeName: '',
+      codeLength: 6,
+      codeType: 1,
+      validTimeSeconds: 300,
+      intervalSeconds: 60,
+      duplicatePolicy: 1,
+      caseAuthPolicy: 1,
+      returnVerifyCode: false,
+      mockVerifyCode: '123456',
+      maxSendPerPhonePerDay: 20,
+      maxSendPerIpPerHour: 30,
+      maxVerifyFailuresPerPhonePerHour: 12,
+      maxVerifyFailuresPerIpPerHour: 24,
+      captchaTtlSeconds: 180,
+      captchaTriggerVerifyFailuresPerPhone: 3,
+      captchaTriggerVerifyFailuresPerIp: 5,
+      blockPhoneFailureThreshold: 6,
+      blockIpFailureThreshold: 10,
+      blockPhoneDurationMinutes: 30,
+      blockIpDurationMinutes: 30,
+    },
+    wechatAuth: {
+      enabled: true,
+      provider: 'mock',
+      appId: '',
+      appSecret: '',
+      authorizeEndpoint: 'https://open.weixin.qq.com/connect/qrconnect',
+      accessTokenEndpoint: 'https://api.weixin.qq.com/sns/oauth2/access_token',
+      userInfoEndpoint: 'https://api.weixin.qq.com/sns/userinfo',
+      callbackPath: '/api/auth/wechat/callback',
+      defaultRedirectPath: '/',
+      mockUserId: 'mock_wechat_user',
+      mockUnionId: 'mock_wechat_union',
+      mockDisplayName: '微信旅人',
+      mockAvatarUrl: '',
+    },
+    authSession: {
+      refreshCookieName: 'genarrative_refresh_session',
+      refreshSessionTtlDays: 30,
+      refreshCookieSecure: false,
+      refreshCookieSameSite: 'Lax',
+      refreshCookiePath: '/api/auth',
+    },
+    spacetime: {
+      uri: 'ws://127.0.0.1:3000',
+      databaseName: 'genarrative-test',
+    },
+  };
+}
+
+function createRequest(headers: Record<string, string> = {}) {
+  const normalizedHeaders = Object.fromEntries(
+    Object.entries(headers).map(([key, value]) => [key.toLowerCase(), value]),
+  );
+
+  return {
+    header(name: string) {
+      return normalizedHeaders[name.toLowerCase()] ?? undefined;
+    },
+    ip: '127.0.0.1',
+    userId: undefined,
+    runtimeStoryAuthMode: undefined,
+  } as unknown as Request;
+}
+
+test('shouldUseSpacetimeStoryAuth only accepts the runtime story spacetime marker', () => {
+  assert.equal(
+    shouldUseSpacetimeStoryAuth(
+      createRequest({
+        'x-genarrative-runtime-story-auth': 'spacetime-token',
+      }),
+    ),
+    true,
+  );
+  assert.equal(
+    shouldUseSpacetimeStoryAuth(
+      createRequest({
+        'x-genarrative-runtime-story-auth': 'http-access-token',
+      }),
+    ),
+    false,
+  );
+});
+
+test('authenticateRuntimeStoryViaSpacetime resolves account id from bridge connection', async () => {
+  setRuntimeStoryBridgeConnectorForTest(async () => ({
+    db: {
+      my_auth_state: {
+        iter: () =>
+          [
+            {
+              accountId: 'stdb-account-01',
+            },
+          ][Symbol.iterator](),
+      },
+    },
+    disconnect() {},
+  }));
+
+  const request = createRequest({
+    authorization: 'Bearer stdb-token',
+  });
+
+  await authenticateRuntimeStoryViaSpacetime(request, {
+    config: createTestConfig(),
+  });
+
+  assert.equal(request.userId, 'stdb-account-01');
+  assert.equal(request.runtimeStoryAuthMode, 'spacetime');
+
+  resetRuntimeStoryBridgeConnectorForTest();
+});
+
+test('createRuntimeStorySnapshotRepository uses STDB snapshot rows when request is marked as spacetime', async () => {
+  let savedSnapshotInput: Record<string, unknown> | null = null;
+
+  setRuntimeStoryBridgeConnectorForTest(async () => ({
+    db: {
+      my_snapshot: {
+        iter: () =>
+          [
+            {
+              version: 8,
+              savedAtMs: BigInt(Date.parse('2026-04-20T00:00:00.000Z')),
+              gameStateJson: JSON.stringify({
+                worldType: 'WUXIA',
+                currentScene: 'Story',
+              }),
+              bottomTab: 'adventure',
+              currentStoryJson: JSON.stringify({
+                text: '桥接后的快照',
+                options: [],
+              }),
+            },
+          ][Symbol.iterator](),
+      },
+    },
+    procedures: {
+      async saveSnapshot(input: Record<string, unknown>) {
+        savedSnapshotInput = input;
+        return {
+          ok: true,
+          message: 'ok',
+        };
+      },
+    },
+    disconnect() {},
+  }));
+
+  const request = createRequest({
+    authorization: 'Bearer stdb-token',
+    'user-agent': 'test-agent',
+  });
+  request.runtimeStoryAuthMode = 'spacetime';
+
+  const repository = createRuntimeStorySnapshotRepository({
+    request,
+    config: createTestConfig(),
+    runtimeRepository: {
+      async getSnapshot() {
+        throw new Error('should not hit legacy repository');
+      },
+      async putSnapshot() {
+        throw new Error('should not hit legacy repository');
+      },
+    } as never,
+  });
+
+  const snapshot = await repository.getSnapshot('ignored-user-id');
+  assert.equal(snapshot?.version, 8);
+  assert.equal(snapshot?.gameState.worldType, 'WUXIA');
+
+  const persisted = await repository.putSnapshot('ignored-user-id', {
+    savedAt: '2026-04-20T00:00:00.000Z',
+    bottomTab: 'adventure',
+    gameState: {
+      worldType: 'WUXIA',
+      currentScene: 'Story',
+    },
+    currentStory: {
+      text: '桥接后的快照',
+      options: [],
+    },
+  });
+
+  assert.equal(persisted.version, 8);
+  assert.equal(savedSnapshotInput?.bottomTab, 'adventure');
+  assert.equal(
+    savedSnapshotInput?.currentStoryJson,
+    JSON.stringify({
+      text: '桥接后的快照',
+      options: [],
+    }),
+  );
+
+  resetRuntimeStoryBridgeConnectorForTest();
+});
diff --git a/server-node/src/modules/story/storySpacetimeBridge.ts b/server-node/src/modules/story/storySpacetimeBridge.ts
index ac5129bf..0af14fb9 100644
--- a/server-node/src/modules/story/storySpacetimeBridge.ts
+++ b/server-node/src/modules/story/storySpacetimeBridge.ts
@@ -23,6 +23,8 @@ type StoryStdbBridgeContext = {
   config: AppConfig;
 };
 
+type StoryBridgeDbConnection = Awaited<ReturnType<typeof connectWithToken>>;
+
 function readBearerToken(request: Request) {
   const authorization = request.header('authorization')?.trim() || '';
   if (!authorization.startsWith('Bearer ')) {
@@ -102,9 +104,9 @@ async function connectWithToken(config: AppConfig, token: string) {
 async function withBridgeConnection<T>(
   config: AppConfig,
   token: string,
-  run: (connection: DbConnection) => Promise<T>,
+  run: (connection: StoryBridgeDbConnection) => Promise<T>,
 ) {
-  const connection = await connectWithToken(config, token);
+  const connection = await runtimeStoryBridgeConnector(config, token);
   try {
     return await run(connection);
   } finally {
@@ -112,6 +114,18 @@ async function withBridgeConnection<T>(
   }
 }
 
+let runtimeStoryBridgeConnector = connectWithToken;
+
+export function setRuntimeStoryBridgeConnectorForTest(
+  connector: typeof connectWithToken,
+) {
+  runtimeStoryBridgeConnector = connector;
+}
+
+export function resetRuntimeStoryBridgeConnectorForTest() {
+  runtimeStoryBridgeConnector = connectWithToken;
+}
+
 export function shouldUseSpacetimeStoryAuth(request: Request) {
   return (
     request.header(STORY_STDB_AUTH_HEADER)?.trim() === 'spacetime-token'