diff --git a/packages/common/nbstore/src/impls/cloud/index.ts b/packages/common/nbstore/src/impls/cloud/index.ts
index c8b0cda3e8..2e2e818bb3 100644
--- a/packages/common/nbstore/src/impls/cloud/index.ts
+++ b/packages/common/nbstore/src/impls/cloud/index.ts
@@ -3,11 +3,13 @@ import { CloudAwarenessStorage } from './awareness';
 import { CloudBlobStorage } from './blob';
 import { CloudDocStorage } from './doc';
 import { StaticCloudDocStorage } from './doc-static';
+import { CloudIndexerStorage } from './indexer';
 
 export * from './awareness';
 export * from './blob';
 export * from './doc';
 export * from './doc-static';
+export * from './indexer';
 export * from './socket';
 
 export const cloudStorages = [
@@ -15,4 +17,5 @@ export const cloudStorages = [
   StaticCloudDocStorage,
   CloudBlobStorage,
   CloudAwarenessStorage,
+  CloudIndexerStorage,
 ] satisfies StorageConstructor[];
diff --git a/packages/common/nbstore/src/impls/cloud/indexer.ts b/packages/common/nbstore/src/impls/cloud/indexer.ts
new file mode 100644
index 0000000000..5ff20427af
--- /dev/null
+++ b/packages/common/nbstore/src/impls/cloud/indexer.ts
@@ -0,0 +1,142 @@
+import {
+  type AggregateInput,
+  indexerAggregateQuery,
+  indexerSearchQuery,
+  type SearchInput,
+} from '@affine/graphql';
+import { Observable } from 'rxjs';
+
+import {
+  type AggregateOptions,
+  type AggregateResult,
+  type IndexerDocument,
+  type IndexerSchema,
+  IndexerStorageBase,
+  type Query,
+  type SearchOptions,
+  type SearchResult,
+} from '../../storage/indexer';
+import { HttpConnection } from './http';
+
+interface CloudIndexerStorageOptions {
+  serverBaseUrl: string;
+  id: string;
+}
+
+export class CloudIndexerStorage extends IndexerStorageBase {
+  static readonly identifier = 'CloudIndexerStorage';
+  readonly isReadonly = true;
+  readonly connection = new HttpConnection(this.options.serverBaseUrl);
+
+  constructor(private readonly options: CloudIndexerStorageOptions) {
+    super();
+  }
+
+  override async search<
+    T extends keyof IndexerSchema,
+    const O extends SearchOptions<T>,
+  >(table: T, query: Query<T>, options?: O): Promise<SearchResult<T, O>> {
+    const res = await this.connection.gql({
+      query: indexerSearchQuery,
+      variables: {
+        id: this.options.id,
+        input: {
+          table,
+          query,
+          options,
+        } as SearchInput,
+      },
+    });
+    const result = res.workspace.search as unknown as SearchResult<T, O>;
+    return result;
+  }
+
+  override search$<
+    T extends keyof IndexerSchema,
+    const O extends SearchOptions<T>,
+  >(table: T, query: Query<T>, options?: O): Observable<SearchResult<T, O>> {
+    return new Observable(observer => {
+      this.search(table, query, options)
+        .then(data => {
+          observer.next(data);
+          observer.complete();
+        })
+        .catch(error => {
+          observer.error(error);
+        });
+    });
+  }
+
+  override async aggregate<
+    T extends keyof IndexerSchema,
+    const O extends AggregateOptions<T>,
+  >(
+    table: T,
+    query: Query<T>,
+    field: keyof IndexerSchema[T],
+    options?: O
+  ): Promise<AggregateResult<T, O>> {
+    const res = await this.connection.gql({
+      query: indexerAggregateQuery,
+      variables: {
+        id: this.options.id,
+        input: { table, query, field, options } as AggregateInput,
+      },
+    });
+    const result = res.workspace.aggregate as unknown as AggregateResult<T, O>;
+    return result;
+  }
+
+  override aggregate$<
+    T extends keyof IndexerSchema,
+    const O extends AggregateOptions<T>,
+  >(
+    table: T,
+    query: Query<T>,
+    field: keyof IndexerSchema[T],
+    options?: O
+  ): Observable<AggregateResult<T, O>> {
+    return new Observable(observer => {
+      this.aggregate(table, query, field, options)
+        .then(data => {
+          observer.next(data);
+          observer.complete();
+        })
+        .catch(error => {
+          observer.error(error);
+        });
+    });
+  }
+
+  override deleteByQuery<T extends keyof IndexerSchema>(
+    _table: T,
+    _query: Query<T>
+  ): Promise<void> {
+    return Promise.resolve();
+  }
+
+  override insert<T extends keyof IndexerSchema>(
+    _table: T,
+    _document: IndexerDocument<T>
+  ): Promise<void> {
+    return Promise.resolve();
+  }
+
+  override delete<T extends keyof IndexerSchema>(
+    _table: T,
+    _id: string
+  ): Promise<void> {
+    return Promise.resolve();
+  }
+
+  override update<T extends keyof IndexerSchema>(
+    _table: T,
+    _document: IndexerDocument<T>
+  ): Promise<void> {
+    return Promise.resolve();
+  }
+
+  override refresh<T extends keyof IndexerSchema>(_table: T): Promise<void> {
+    return Promise.resolve();
+  }
+}
diff --git a/packages/frontend/core/src/modules/feature-flag/constant.ts b/packages/frontend/core/src/modules/feature-flag/constant.ts
index 76a2325d38..12058a6b14 100644
--- a/packages/frontend/core/src/modules/feature-flag/constant.ts
+++ b/packages/frontend/core/src/modules/feature-flag/constant.ts
@@ -3,6 +3,7 @@ import type { FlagInfo } from './types';
 // const isNotStableBuild = BUILD_CONFIG.appBuildType !== 'stable';
 const isDesktopEnvironment = BUILD_CONFIG.isElectron;
 const isCanaryBuild = BUILD_CONFIG.appBuildType === 'canary';
+const isBetaBuild = BUILD_CONFIG.appBuildType === 'beta';
 const isMobile = BUILD_CONFIG.isMobileEdition;
 
 export const AFFINE_FLAGS = {
@@ -317,6 +318,13 @@ export const AFFINE_FLAGS = {
     configurable: isCanaryBuild,
     defaultState: false,
   },
+  enable_cloud_indexer: {
+    category: 'affine',
+    displayName: 'Enable Cloud Indexer',
+    description: 'Use cloud indexer to search docs',
+    configurable: isBetaBuild || isCanaryBuild,
+    defaultState: false,
+  },
 } satisfies { [key in string]: FlagInfo };
 
 // oxlint-disable-next-line no-redeclare
diff --git a/packages/frontend/core/src/modules/workspace-engine/impls/cloud.ts b/packages/frontend/core/src/modules/workspace-engine/impls/cloud.ts
index 238025049e..68e076711d 100644
--- a/packages/frontend/core/src/modules/workspace-engine/impls/cloud.ts
+++ b/packages/frontend/core/src/modules/workspace-engine/impls/cloud.ts
@@ -1,3 +1,4 @@
+import { FeatureFlagService } from '@affine/core/modules/feature-flag';
 import { DebugLogger } from '@affine/debug';
 import {
   createWorkspaceMutation,
@@ -85,6 +86,7 @@ const logger = new DebugLogger('affine:cloud-workspace-flavour-provider');
 class CloudWorkspaceFlavourProvider implements WorkspaceFlavourProvider {
   private readonly authService: AuthService;
   private readonly graphqlService: GraphQLService;
+  private readonly featureFlagService: FeatureFlagService;
   private readonly unsubscribeAccountChanged: () => void;
 
   constructor(
@@ -93,6 +95,7 @@ class CloudWorkspaceFlavourProvider implements WorkspaceFlavourProvider {
   ) {
     this.authService = server.scope.get(AuthService);
     this.graphqlService = server.scope.get(GraphQLService);
+    this.featureFlagService = server.scope.get(FeatureFlagService);
     this.unsubscribeAccountChanged = this.server.scope.eventBus.on(
       AccountChanged,
       () => {
@@ -474,14 +477,24 @@ class CloudWorkspaceFlavourProvider implements WorkspaceFlavourProvider {
             id: `${this.flavour}:${workspaceId}`,
           },
         },
-        indexer: {
-          name: 'IndexedDBIndexerStorage',
-          opts: {
-            flavour: this.flavour,
-            type: 'workspace',
-            id: workspaceId,
-          },
-        },
+        indexer: this.featureFlagService.flags.enable_cloud_indexer.value
+          ? {
+              name: 'CloudIndexerStorage',
+              opts: {
+                flavour: this.flavour,
+                type: 'workspace',
+                id: workspaceId,
+                serverBaseUrl: this.server.serverMetadata.baseUrl,
+              },
+            }
+          : {
+              name: 'IndexedDBIndexerStorage',
+              opts: {
+                flavour: this.flavour,
+                type: 'workspace',
+                id: workspaceId,
+              },
+            },
         indexerSync: {
           name: 'IndexedDBIndexerSyncStorage',
           opts: {