diff --git a/packages/common/nbstore/package.json b/packages/common/nbstore/package.json
index f40500c6d58bc..5a9c66757ce47 100644
--- a/packages/common/nbstore/package.json
+++ b/packages/common/nbstore/package.json
@@ -20,6 +20,7 @@
     "lodash-es": "^4.17.21",
     "nanoid": "^5.0.9",
     "rxjs": "^7.8.1",
+    "y-protocols": "^1.0.6",
     "yjs": "patch:yjs@npm%3A13.6.18#~/.yarn/patches/yjs-npm-13.6.18-ad0d5f7c43.patch"
   },
   "devDependencies": {
diff --git a/packages/common/nbstore/src/__tests__/frontend.spec.ts b/packages/common/nbstore/src/__tests__/frontend.spec.ts
index 941a13a4d8754..4a00fbae581f4 100644
--- a/packages/common/nbstore/src/__tests__/frontend.spec.ts
+++ b/packages/common/nbstore/src/__tests__/frontend.spec.ts
@@ -1,10 +1,14 @@
 import 'fake-indexeddb/auto';
 
-import { test, vitest } from 'vitest';
+import { expect, test, vitest } from 'vitest';
+import { Awareness } from 'y-protocols/awareness.js';
 import { Doc as YDoc } from 'yjs';
 
+import { AwarenessFrontend } from '../frontend/awareness';
 import { DocFrontend } from '../frontend/doc';
+import { BroadcastChannelAwarenessStorage } from '../impls/broadcast-channel/awareness';
 import { IndexedDBDocStorage } from '../impls/idb';
+import { AwarenessSync } from '../sync/awareness';
 import { expectYjsEqual } from './utils';
 
 test('doc', async () => {
@@ -48,3 +52,86 @@ test('doc', async () => {
     });
   });
 });
+
+test('awareness', async () => {
+  const storage1 = new BroadcastChannelAwarenessStorage({
+    id: 'ws1',
+    peer: 'a',
+    type: 'workspace',
+  });
+
+  const storage2 = new BroadcastChannelAwarenessStorage({
+    id: 'ws1',
+    peer: 'b',
+    type: 'workspace',
+  });
+
+  await storage1.connect();
+  await storage2.connect();
+
+  // peer a
+  const docA = new YDoc({ guid: 'test-doc' });
+  docA.clientID = 1;
+  const awarenessA = new Awareness(docA);
+
+  // peer b
+  const docB = new YDoc({ guid: 'test-doc' });
+  docB.clientID = 2;
+  const awarenessB = new Awareness(docB);
+
+  // peer c
+  const docC = new YDoc({ guid: 'test-doc' });
+  docC.clientID = 3;
+  const awarenessC = new Awareness(docC);
+
+  {
+    const sync = new AwarenessSync(storage1, [storage2]);
+    const frontend = new AwarenessFrontend(sync);
+    frontend.connect(awarenessA);
+    frontend.connect(awarenessB);
+  }
+  {
+    const sync = new AwarenessSync(storage2, [storage1]);
+    const frontend = new AwarenessFrontend(sync);
+    frontend.connect(awarenessC);
+  }
+
+  awarenessA.setLocalState({
+    hello: 'world',
+  });
+
+  await vitest.waitFor(() => {
+    expect(awarenessB.getStates().get(1)).toEqual({
+      hello: 'world',
+    });
+    expect(awarenessC.getStates().get(1)).toEqual({
+      hello: 'world',
+    });
+  });
+
+  awarenessB.setLocalState({
+    foo: 'bar',
+  });
+
+  await vitest.waitFor(() => {
+    expect(awarenessA.getStates().get(2)).toEqual({
+      foo: 'bar',
+    });
+    expect(awarenessC.getStates().get(2)).toEqual({
+      foo: 'bar',
+    });
+  });
+
+  awarenessC.setLocalState({
+    baz: 'qux',
+  });
+
+  await vitest.waitFor(() => {
+    expect(awarenessA.getStates().get(3)).toEqual({
+      baz: 'qux',
+    });
+    expect(awarenessB.getStates().get(3)).toEqual({
+      baz: 'qux',
+    });
+  });
+});
diff --git a/packages/common/nbstore/src/__tests__/sync.spec.ts b/packages/common/nbstore/src/__tests__/sync.spec.ts
index e6c70452f837f..95ae54032d367 100644
--- a/packages/common/nbstore/src/__tests__/sync.spec.ts
+++ b/packages/common/nbstore/src/__tests__/sync.spec.ts
@@ -9,7 +9,7 @@ import {
   IndexedDBSyncStorage,
 } from '../impls/idb';
 import { SpaceStorage } from '../storage';
-import { SyncEngine } from '../sync';
+import { Sync } from '../sync';
 import { expectYjsEqual } from './utils';
 
 test('doc', async () => {
@@ -53,7 +53,7 @@ test('doc', async () => {
     bin: update,
   });
 
-  const sync = new SyncEngine(peerA, [peerB, peerC]);
+  const sync = new Sync(peerA, [peerB, peerC]);
   sync.start();
 
   await new Promise(resolve => setTimeout(resolve, 1000));
@@ -143,7 +143,7 @@ test('blob', async () => {
   await peerB.connect();
   await peerC.connect();
 
-  const sync = new SyncEngine(peerA, [peerB, peerC]);
+  const sync = new Sync(peerA, [peerB, peerC]);
   sync.start();
 
   await new Promise(resolve => setTimeout(resolve, 1000));
diff --git a/packages/common/nbstore/src/frontend/awareness.ts b/packages/common/nbstore/src/frontend/awareness.ts
new file mode 100644
index 0000000000000..19a092789bc42
--- /dev/null
+++ b/packages/common/nbstore/src/frontend/awareness.ts
@@ -0,0 +1,70 @@
+import { nanoid } from 'nanoid';
+import {
+  applyAwarenessUpdate,
+  type Awareness,
+  encodeAwarenessUpdate,
+} from 'y-protocols/awareness.js';
+
+import type { AwarenessRecord } from '../storage/awareness';
+import type { AwarenessSync } from '../sync/awareness';
+
+type AwarenessChanges = Record<'added' | 'updated' | 'removed', number[]>;
+
+export class AwarenessFrontend {
+  constructor(private readonly sync: AwarenessSync) {}
+
+  connect(awareness: Awareness) {
+    const uniqueId = nanoid();
+    const handleAwarenessUpdate = (
+      changes: AwarenessChanges,
+      origin: string
+    ) => {
+      if (origin === uniqueId) {
+        return;
+      }
+      const changedClients = Object.values(changes).reduce((res, cur) =>
+        res.concat(cur)
+      );
+
+      const update = encodeAwarenessUpdate(awareness, changedClients);
+
+      this.sync
+        .update(
+          {
+            docId: awareness.doc.guid,
+            bin: update,
+          },
+          uniqueId
+        )
+        .catch(error => {
+          console.error('update awareness error', error);
+        });
+    };
+
+    awareness.on('update', handleAwarenessUpdate);
+    const handleSyncUpdate = (update: AwarenessRecord, origin?: string) => {
+      if (origin === uniqueId) {
+        // skip self update
+        return;
+      }
+
+      applyAwarenessUpdate(awareness, update.bin, origin);
+    };
+    const handleSyncCollect = () => {
+      return {
+        docId: awareness.doc.guid,
+        bin: encodeAwarenessUpdate(awareness, [awareness.clientID]),
+      };
+    };
+    const unsubscribe = this.sync.subscribeUpdate(
+      awareness.doc.guid,
+      handleSyncUpdate,
+      handleSyncCollect
+    );
+
+    return () => {
+      awareness.off('update', handleAwarenessUpdate);
+      unsubscribe();
+    };
+  }
+}
diff --git a/packages/common/nbstore/src/frontend/blob.ts b/packages/common/nbstore/src/frontend/blob.ts
index 6d4c1e319d1d2..40af3f7773f30 100644
--- a/packages/common/nbstore/src/frontend/blob.ts
+++ b/packages/common/nbstore/src/frontend/blob.ts
@@ -1,10 +1,10 @@
 import type { BlobRecord, BlobStorage } from '../storage';
-import type { BlobSyncEngine } from '../sync/blob';
+import type { BlobSync } from '../sync/blob';
 
 export class BlobFrontend {
   constructor(
     readonly storage: BlobStorage,
-    readonly sync?: BlobSyncEngine
+    readonly sync?: BlobSync
   ) {}
 
   get(blobId: string) {
diff --git a/packages/common/nbstore/src/frontend/doc.ts b/packages/common/nbstore/src/frontend/doc.ts
index 7a1bf7b06d9b1..c95aee1c18195 100644
--- a/packages/common/nbstore/src/frontend/doc.ts
+++ b/packages/common/nbstore/src/frontend/doc.ts
@@ -9,7 +9,7 @@ import {
 } from 'yjs';
 
 import type { DocRecord, DocStorage } from '../storage';
-import type { DocSyncEngine } from '../sync/doc';
+import type { DocSync } from '../sync/doc';
 import { AsyncPriorityQueue } from '../utils/async-priority-queue';
 import { isEmptyUpdate } from '../utils/is-empty-update';
 import { throwIfAborted } from '../utils/throw-if-aborted';
@@ -56,7 +56,7 @@ export class DocFrontend {
 
   constructor(
     private readonly storage: DocStorage,
-    private readonly sync: DocSyncEngine | null,
+    private readonly sync: DocSync | null,
     readonly options: DocFrontendOptions = {}
   ) {}
 
diff --git a/packages/common/nbstore/src/impls/broadcast-channel/awareness.ts b/packages/common/nbstore/src/impls/broadcast-channel/awareness.ts
new file mode 100644
index 0000000000000..837dc04784f91
--- /dev/null
+++ b/packages/common/nbstore/src/impls/broadcast-channel/awareness.ts
@@ -0,0 +1,128 @@
+import { nanoid } from 'nanoid';
+
+import {
+  type AwarenessRecord,
+  AwarenessStorage,
+} from '../../storage/awareness';
+import { BroadcastChannelConnection } from './channel';
+
+type ChannelMessage =
+  | {
+      type: 'awareness-update';
+      docId: string;
+      bin: Uint8Array;
+      origin?: string;
+    }
+  | {
+      type: 'awareness-collect';
+      docId: string;
+      collectId: string;
+    }
+  | {
+      type: 'awareness-collect-fallback';
+      docId: string;
+      bin: Uint8Array;
+      collectId: string;
+    };
+
+export class BroadcastChannelAwarenessStorage extends AwarenessStorage {
+  override readonly storageType = 'awareness';
+  override readonly connection = new BroadcastChannelConnection(this.options);
+  get channel() {
+    return this.connection.inner;
+  }
+
+  private readonly subscriptions = new Map<
+    string,
+    Set<{
+      onUpdate: (update: AwarenessRecord, origin?: string) => void;
+      onCollect: () => AwarenessRecord;
+    }>
+  >();
+
+  override update(record: AwarenessRecord, origin?: string): Promise<void> {
+    const subscribers = this.subscriptions.get(record.docId);
+    if (subscribers) {
+      subscribers.forEach(subscriber => subscriber.onUpdate(record, origin));
+    }
+    this.channel.postMessage({
+      type: 'awareness-update',
+      docId: record.docId,
+      bin: record.bin,
+      origin,
+    } satisfies ChannelMessage);
+    return Promise.resolve();
+  }
+
+  override subscribeUpdate(
+    id: string,
+    onUpdate: (update: AwarenessRecord, origin?: string) => void,
+    onCollect: () => AwarenessRecord
+  ): () => void {
+    const subscribers = this.subscriptions.get(id) ?? new Set();
+    subscribers.forEach(subscriber => {
+      const fallback = subscriber.onCollect();
+      onUpdate(fallback);
+    });
+
+    const collectUniqueId = nanoid();
+
+    const onChannelMessage = (message: MessageEvent<ChannelMessage>) => {
+      if (
+        message.data.type === 'awareness-update' &&
+        message.data.docId === id
+      ) {
+        onUpdate(
+          {
+            docId: message.data.docId,
+            bin: message.data.bin,
+          },
+          message.data.origin
+        );
+      }
+      if (
+        message.data.type === 'awareness-collect' &&
+        message.data.docId === id
+      ) {
+        const fallback = onCollect();
+        if (fallback) {
+          this.channel.postMessage({
+            type: 'awareness-collect-fallback',
+            docId: message.data.docId,
+            bin: fallback.bin,
+            collectId: collectUniqueId,
+          } satisfies ChannelMessage);
+        }
+      }
+      if (
+        message.data.type === 'awareness-collect-fallback' &&
+        message.data.docId === id &&
+        message.data.collectId === collectUniqueId
+      ) {
+        onUpdate({
+          docId: message.data.docId,
+          bin: message.data.bin,
+        });
+      }
+    };
+
+    this.channel.addEventListener('message', onChannelMessage);
+    this.channel.postMessage({
+      type: 'awareness-collect',
+      docId: id,
+      collectId: collectUniqueId,
+    } satisfies ChannelMessage);
+
+    const subscriber = {
+      onUpdate,
+      onCollect,
+    };
+    subscribers.add(subscriber);
+    this.subscriptions.set(id, subscribers);
+
+    return () => {
+      subscribers.delete(subscriber);
+      this.channel.removeEventListener('message', onChannelMessage);
+    };
+  }
+}
diff --git a/packages/common/nbstore/src/impls/broadcast-channel/channel.ts b/packages/common/nbstore/src/impls/broadcast-channel/channel.ts
new file mode 100644
index 0000000000000..e3d7b1327bef2
--- /dev/null
+++ b/packages/common/nbstore/src/impls/broadcast-channel/channel.ts
@@ -0,0 +1,23 @@
+import { Connection } from '../../connection';
+import type { StorageOptions } from '../../storage';
+
+export class BroadcastChannelConnection extends Connection<BroadcastChannel> {
+  readonly channelName = `channel:${this.opts.peer}:${this.opts.type}:${this.opts.id}`;
+
+  constructor(private readonly opts: StorageOptions) {
+    super();
+  }
+
+  override async doConnect() {
+    return new BroadcastChannel(this.channelName);
+  }
+
+  override async doDisconnect() {
+    this.close();
+  }
+
+  private close(error?: Error) {
+    this.maybeConnection?.close();
+    this.setStatus('closed', error);
+  }
+}
diff --git a/packages/common/nbstore/src/impls/cloud/awareness.ts b/packages/common/nbstore/src/impls/cloud/awareness.ts
new file mode 100644
index 0000000000000..f15b8916293b9
--- /dev/null
+++ b/packages/common/nbstore/src/impls/cloud/awareness.ts
@@ -0,0 +1,148 @@
+import type { SocketOptions } from 'socket.io-client';
+
+import { share } from '../../connection';
+import {
+  type AwarenessRecord,
+  AwarenessStorage,
+  type AwarenessStorageOptions,
+} from '../../storage/awareness';
+import {
+  base64ToUint8Array,
+  SocketConnection,
+  uint8ArrayToBase64,
+} from './socket';
+
+interface CloudAwarenessStorageOptions extends AwarenessStorageOptions {
+  socketOptions: SocketOptions;
+}
+
+export class CloudAwarenessStorage extends AwarenessStorage<CloudAwarenessStorageOptions> {
+  connection = share(
+    new SocketConnection(this.peer, this.options.socketOptions)
+  );
+
+  private get socket() {
+    return this.connection.inner;
+  }
+
+  override async connect(): Promise<void> {
+    await super.connect();
+  }
+
+  override async update(record: AwarenessRecord): Promise<void> {
+    const encodedUpdate = await uint8ArrayToBase64(record.bin);
+    this.socket.emit('space:update-awareness', {
+      spaceType: this.spaceType,
+      spaceId: this.spaceId,
+      docId: record.docId,
+      awarenessUpdate: encodedUpdate,
+    });
+  }
+
+  override subscribeUpdate(
+    id: string,
+    onUpdate: (update: AwarenessRecord, origin?: string) => void,
+    onCollect: () => AwarenessRecord
+  ): () => void {
+    // leave awareness
+    const leave = () => {
+      this.socket.emit('space:leave-awareness', {
+        spaceType: this.spaceType,
+        spaceId: this.spaceId,
+        docId: id,
+      });
+    };
+
+    // join awareness, and collect awareness from others
+    const joinAndCollect = async () => {
+      await this.socket.emitWithAck('space:join-awareness', {
+        spaceType: this.spaceType,
+        spaceId: this.spaceId,
+        docId: id,
+        clientVersion: BUILD_CONFIG.appVersion,
+      });
+      this.socket.emit('space:load-awarenesses', {
+        spaceType: this.spaceType,
+        spaceId: this.spaceId,
+        docId: id,
+      });
+    };
+
+    joinAndCollect().catch(err => console.error('awareness join failed', err));
+
+    const unsubscribeConnectionStatusChanged = this.connection.onStatusChanged(
+      status => {
+        if (status === 'connected') {
+          joinAndCollect().catch(err =>
+            console.error('awareness join failed', err)
+          );
+        }
+      }
+    );
+
+    const handleCollectAwareness = ({
+      spaceId,
+      spaceType,
+      docId,
+    }: {
+      spaceId: string;
+      spaceType: string;
+      docId: string;
+    }) => {
+      if (
+        spaceId === this.spaceId &&
+        spaceType === this.spaceType &&
+        docId === id
+      ) {
+        (async () => {
+          const record = onCollect();
+          const encodedUpdate = await uint8ArrayToBase64(record.bin);
+          this.socket.emit('space:update-awareness', {
+            spaceType: this.spaceType,
+            spaceId: this.spaceId,
+            docId: record.docId,
+            awarenessUpdate: encodedUpdate,
+          });
+        })().catch(err => console.error('awareness upload failed', err));
+      }
+    };
+
+    const handleBroadcastAwarenessUpdate = ({
+      spaceType,
+      spaceId,
+      docId,
+      awarenessUpdate,
+    }: {
+      spaceType: string;
+      spaceId: string;
+      docId: string;
+      awarenessUpdate: string;
+    }) => {
+      if (
+        spaceId === this.spaceId &&
+        spaceType === this.spaceType &&
+        docId === id
+      ) {
+        onUpdate({
+          bin: base64ToUint8Array(awarenessUpdate),
+          docId: id,
+        });
+      }
+    };
+
+    this.socket.on('space:collect-awareness', handleCollectAwareness);
+    this.socket.on(
+      'space:broadcast-awareness-update',
+      handleBroadcastAwarenessUpdate
+    );
+    return () => {
+      leave();
+      this.socket.off('space:collect-awareness', handleCollectAwareness);
+      this.socket.off(
+        'space:broadcast-awareness-update',
+        handleBroadcastAwarenessUpdate
+      );
+      unsubscribeConnectionStatusChanged();
+    };
+  }
+}
diff --git a/packages/common/nbstore/src/impls/cloud/doc.ts b/packages/common/nbstore/src/impls/cloud/doc.ts
index 327ac777fa90c..6dd855ae521fa 100644
--- a/packages/common/nbstore/src/impls/cloud/doc.ts
+++ b/packages/common/nbstore/src/impls/cloud/doc.ts
@@ -1,4 +1,3 @@
-import { noop } from 'lodash-es';
 import type { SocketOptions } from 'socket.io-client';
 
 import { share } from '../../connection';
@@ -33,7 +32,9 @@ export class CloudDocStorage extends DocStorage<CloudDocStorageOptions> {
     await super.connect();
     this.connection.onStatusChanged(status => {
       if (status === 'connected') {
-        this.join().catch(noop);
+        this.join().catch(err => {
+          console.error('doc storage join failed', err);
+        });
         this.socket.on('space:broadcast-doc-update', this.onServerUpdate);
       }
     });
diff --git a/packages/common/nbstore/src/impls/cloud/index.ts b/packages/common/nbstore/src/impls/cloud/index.ts
index d476ae6eb9b92..f4829dcdbfe8a 100644
--- a/packages/common/nbstore/src/impls/cloud/index.ts
+++ b/packages/common/nbstore/src/impls/cloud/index.ts
@@ -1,2 +1,3 @@
+export * from './awareness';
 export * from './blob';
 export * from './doc';
diff --git a/packages/common/nbstore/src/impls/cloud/socket.ts b/packages/common/nbstore/src/impls/cloud/socket.ts
index 61f0a2403118b..de80a479912b1 100644
--- a/packages/common/nbstore/src/impls/cloud/socket.ts
+++ b/packages/common/nbstore/src/impls/cloud/socket.ts
@@ -29,6 +29,19 @@ interface ServerEvents {
     timestamp: number;
     editor: string;
   };
+
+  'space:collect-awareness': {
+    spaceType: string;
+    spaceId: string;
+    docId: string;
+  };
+
+  'space:broadcast-awareness-update': {
+    spaceType: string;
+    spaceId: string;
+    docId: string;
+    awarenessUpdate: string;
+  };
 }
 
 interface ClientEvents {
@@ -52,6 +65,19 @@ interface ClientEvents {
     docId: string;
   };
 
+  'space:update-awareness': {
+    spaceType: string;
+    spaceId: string;
+    docId: string;
+    awarenessUpdate: string;
+  };
+
+  'space:load-awarenesses': {
+    spaceType: string;
+    spaceId: string;
+    docId: string;
+  };
+
   'space:push-doc-update': [
     { spaceType: string; spaceId: string; docId: string; updates: string },
     { timestamp: number },
diff --git a/packages/common/nbstore/src/impls/idb/db.ts b/packages/common/nbstore/src/impls/idb/db.ts
index 5397698ecdcfd..60129fe1515b5 100644
--- a/packages/common/nbstore/src/impls/idb/db.ts
+++ b/packages/common/nbstore/src/impls/idb/db.ts
@@ -34,7 +34,7 @@ export class IDBConnection extends Connection<{
           this.setStatus('error', new Error('Blocked by other tabs.'));
         },
       }),
-      channel: new BroadcastChannel(this.dbName),
+      channel: new BroadcastChannel('idb:' + this.dbName),
     };
   }
 
diff --git a/packages/common/nbstore/src/storage/awareness.ts b/packages/common/nbstore/src/storage/awareness.ts
new file mode 100644
index 0000000000000..5b47f3a450105
--- /dev/null
+++ b/packages/common/nbstore/src/storage/awareness.ts
@@ -0,0 +1,27 @@
+import { Storage, type StorageOptions } from './storage';
+
+export interface AwarenessStorageOptions extends StorageOptions {}
+
+export type AwarenessRecord = {
+  docId: string;
+  bin: Uint8Array;
+};
+
+export abstract class AwarenessStorage<
+  Options extends AwarenessStorageOptions = AwarenessStorageOptions,
+> extends Storage<Options> {
+  override readonly storageType = 'awareness';
+
+  /**
+   * Update the awareness record.
+   *
+   * @param origin - Internal identifier to recognize the source in the "update" event. Will not be stored or transferred.
+   */
+  abstract update(record: AwarenessRecord, origin?: string): Promise<void>;
+
+  abstract subscribeUpdate(
+    id: string,
+    onUpdate: (update: AwarenessRecord, origin?: string) => void,
+    onCollect: () => AwarenessRecord
+  ): () => void;
+}
diff --git a/packages/common/nbstore/src/storage/index.ts b/packages/common/nbstore/src/storage/index.ts
index 53cc9f3ba10a8..c053c664f1b9d 100644
--- a/packages/common/nbstore/src/storage/index.ts
+++ b/packages/common/nbstore/src/storage/index.ts
@@ -3,7 +3,7 @@ import EventEmitter2 from 'eventemitter2';
 import type { ConnectionStatus } from '../connection';
 import type { BlobStorage } from './blob';
 import type { DocStorage } from './doc';
-import { type Storage, type StorageType } from './storage';
+import type { Storage, StorageType } from './storage';
 import type { SyncStorage } from './sync';
 
 type Storages = DocStorage | BlobStorage | SyncStorage;
@@ -22,7 +22,10 @@ export class SpaceStorage {
   tryGet<T extends StorageType>(
     type: T
   ): Extract<Storages, { storageType: T }> | undefined {
-    return this.storages.get(type) as Extract<Storages, { storageType: T }>;
+    return this.storages.get(type) as unknown as Extract<
+      Storages,
+      { storageType: T }
+    >;
   }
 
   get<T extends StorageType>(type: T): Extract<Storages, { storageType: T }> {
diff --git a/packages/common/nbstore/src/storage/storage.ts b/packages/common/nbstore/src/storage/storage.ts
index 32e8a762adcf7..be37afcbdd4fa 100644
--- a/packages/common/nbstore/src/storage/storage.ts
+++ b/packages/common/nbstore/src/storage/storage.ts
@@ -1,7 +1,7 @@
 import type { Connection } from '../connection';
 
 export type SpaceType = 'workspace' | 'userspace';
-export type StorageType = 'blob' | 'doc' | 'sync';
+export type StorageType = 'blob' | 'doc' | 'sync' | 'awareness';
 
 export interface StorageOptions {
   peer: string;
diff --git a/packages/common/nbstore/src/sync/awareness/index.ts b/packages/common/nbstore/src/sync/awareness/index.ts
new file mode 100644
index 0000000000000..cfdcbf9047e20
--- /dev/null
+++ b/packages/common/nbstore/src/sync/awareness/index.ts
@@ -0,0 +1,30 @@
+import type {
+  AwarenessRecord,
+  AwarenessStorage,
+} from '../../storage/awareness';
+
+export class AwarenessSync {
+  constructor(
+    readonly local: AwarenessStorage,
+    readonly remotes: AwarenessStorage[]
+  ) {}
+
+  async update(record: AwarenessRecord, origin?: string) {
+    await Promise.all(
+      [this.local, ...this.remotes].map(peer => peer.update(record, origin))
+    );
+  }
+
+  subscribeUpdate(
+    id: string,
+    onUpdate: (update: AwarenessRecord, origin?: string) => void,
+    onCollect: () => AwarenessRecord
+  ): () => void {
+    const unsubscribes = [this.local, ...this.remotes].map(peer =>
+      peer.subscribeUpdate(id, onUpdate, onCollect)
+    );
+    return () => {
+      unsubscribes.forEach(unsubscribe => unsubscribe());
+    };
+  }
+}
diff --git a/packages/common/nbstore/src/sync/blob/index.ts b/packages/common/nbstore/src/sync/blob/index.ts
index a04a9920df22d..7a337b5bef7d6 100644
--- a/packages/common/nbstore/src/sync/blob/index.ts
+++ b/packages/common/nbstore/src/sync/blob/index.ts
@@ -3,7 +3,7 @@ import { difference } from 'lodash-es';
 import type { BlobRecord, BlobStorage } from '../../storage';
 import { MANUALLY_STOP, throwIfAborted } from '../../utils/throw-if-aborted';
 
-export class BlobSyncEngine {
+export class BlobSync {
   private abort: AbortController | null = null;
 
   constructor(
diff --git a/packages/common/nbstore/src/sync/doc/index.ts b/packages/common/nbstore/src/sync/doc/index.ts
index 7b7fb63d4dc12..0585556b231af 100644
--- a/packages/common/nbstore/src/sync/doc/index.ts
+++ b/packages/common/nbstore/src/sync/doc/index.ts
@@ -1,7 +1,7 @@
 import type { DocStorage, SyncStorage } from '../../storage';
 import { DocSyncPeer } from './peer';
 
-export class DocSyncEngine {
+export class DocSync {
   private readonly peers: DocSyncPeer[];
   private abort: AbortController | null = null;
 
diff --git a/packages/common/nbstore/src/sync/index.ts b/packages/common/nbstore/src/sync/index.ts
index 22b640a6c12cd..58bfea2700273 100644
--- a/packages/common/nbstore/src/sync/index.ts
+++ b/packages/common/nbstore/src/sync/index.ts
@@ -1,10 +1,10 @@
 import type { BlobStorage, DocStorage, SpaceStorage } from '../storage';
-import { BlobSyncEngine } from './blob';
-import { DocSyncEngine } from './doc';
+import { BlobSync } from './blob';
+import { DocSync } from './doc';
 
-export class SyncEngine {
-  private readonly doc: DocSyncEngine | null;
-  private readonly blob: BlobSyncEngine | null;
+export class Sync {
+  private readonly doc: DocSync | null;
+  private readonly blob: BlobSync | null;
 
   constructor(
     readonly local: SpaceStorage,
@@ -16,7 +16,7 @@ export class SyncEngine {
 
     this.doc =
       doc && sync
-        ? new DocSyncEngine(
+        ? new DocSync(
             doc,
             sync,
             peers
@@ -25,7 +25,7 @@ export class SyncEngine {
           )
         : null;
     this.blob = blob
-      ? new BlobSyncEngine(
+      ? new BlobSync(
           blob,
           peers
             .map(peer => peer.tryGet('blob'))
diff --git a/yarn.lock b/yarn.lock
index 3e1e6c98aec90..714bc07cfa4f8 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -747,6 +747,7 @@ __metadata:
     rxjs: "npm:^7.8.1"
     socket.io-client: "npm:^4.8.1"
     vitest: "npm:2.1.8"
+    y-protocols: "npm:^1.0.6"
     yjs: "patch:yjs@npm%3A13.6.18#~/.yarn/patches/yjs-npm-13.6.18-ad0d5f7c43.patch"
   peerDependencies:
     "@affine/electron-api": "workspace:*"
@@ -15060,9 +15061,9 @@ __metadata:
   linkType: hard
 
 "@ungap/structured-clone@npm:^1.0.0":
-  version: 1.2.1
-  resolution: "@ungap/structured-clone@npm:1.2.1"
-  checksum: 10/6770f71e8183311b2871601ddb02d62a26373be7cf2950cb546a345a2305c75b502e36ce80166120aa2f5f1ea1562141684651ebbfcc711c58acd32035d3e545
+  version: 1.2.0
+  resolution: "@ungap/structured-clone@npm:1.2.0"
+  checksum: 10/c6fe89a505e513a7592e1438280db1c075764793a2397877ff1351721fe8792a966a5359769e30242b3cd023f2efb9e63ca2ca88019d73b564488cc20e3eab12
   languageName: node
   linkType: hard