diff --git a/.eslintrc.js b/.eslintrc.js
index 8506d3f8e5388..58baf6dabff2e 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -54,7 +54,7 @@ const allPackages = [
   'packages/common/debug',
   'packages/common/env',
   'packages/common/infra',
-  'packages/common/theme',
+  'packages/common/nbstore',
   'tools/cli',
 ];
 
diff --git a/packages/common/nbstore/README.md b/packages/common/nbstore/README.md
new file mode 100644
index 0000000000000..ce8e3118ecb94
--- /dev/null
+++ b/packages/common/nbstore/README.md
@@ -0,0 +1,69 @@
+# Space Storage
+
+## Usage
+
+### Independent Storage usage
+
+```ts
+import type { ConnectionStatus } from '@affine/nbstore';
+import { IndexedDBDocStorage } from '@affine/nbstore/idb';
+
+const storage = new IndexedDBDocStorage({
+  peer: 'local'
+  spaceId: 'my-new-workspace',
+});
+
+await storage.connect();
+storage.connection.onStatusChange((status: ConnectionStatus, error?: Error) => {
+  ui.show(status, error);
+});
+
+// { docId: string, bin: Uint8Array, timestamp: Date, editor?: string } | null
+const doc = await storage.getDoc('my-first-doc');
+```
+
+### Use All storages together
+
+```ts
+import { SpaceStorage } from '@affine/nbstore';
+import type { ConnectionStatus } from '@affine/nbstore';
+import { IndexedDBDocStorage } from '@affine/nbstore/idb';
+import { SqliteBlobStorage } from '@affine/nbstore/sqlite';
+
+const storage = new SpaceStorage([new IndexedDBDocStorage({}), new SqliteBlobStorage({})]);
+
+await storage.connect();
+storage.on('connection', ({ storage, status, error }) => {
+  ui.show(storage, status, error);
+});
+
+await storage.get('doc').pushDocUpdate({ docId: 'my-first-doc', bin: new Uint8Array(), editor: 'me' });
+await storage.tryGet('blob')?.get('img');
+```
+
+### Put Storage behind Worker
+
+```ts
+import { SpaceStorageWorkerClient } from '@affine/nbstore/op';
+import type { ConnectionStatus } from '@affine/nbstore';
+import { IndexedDBDocStorage } from '@affine/nbstore/idb';
+
+const client = new SpaceStorageWorkerClient();
+client.addStorage(IndexedDBDocStorage, {
+  // options can only be structure-cloneable type
+  peer: 'local',
+  spaceType: 'workspace',
+  spaceId: 'my-new-workspace',
+});
+
+await client.connect();
+client.ob$('connection', ({ storage, status, error }) => {
+  ui.show(storage, status, error);
+});
+
+await client.call('pushDocUpdate', { docId: 'my-first-doc', bin: new Uint8Array(), editor: 'me' });
+
+// call unregistered op will leads to Error
+// Error { message: 'Handler for operation [listHistory] is not registered.' }
+await client.call('listHistories', { docId: 'my-first-doc' });
+```
diff --git a/packages/common/nbstore/package.json b/packages/common/nbstore/package.json
new file mode 100644
index 0000000000000..c1658ead8db88
--- /dev/null
+++ b/packages/common/nbstore/package.json
@@ -0,0 +1,17 @@
+{
+  "name": "@affine/nbstore",
+  "type": "module",
+  "version": "0.18.0",
+  "private": true,
+  "sideEffects": false,
+  "exports": {
+    ".": "./src/index.ts"
+  },
+  "dependencies": {
+    "@toeverything/infra": "workspace:*",
+    "eventemitter2": "^6.4.9",
+    "lodash-es": "^4.17.21",
+    "rxjs": "^7.8.1",
+    "yjs": "patch:yjs@npm%3A13.6.18#~/.yarn/patches/yjs-npm-13.6.18-ad0d5f7c43.patch"
+  }
+}
diff --git a/packages/common/nbstore/src/connection/connection.ts b/packages/common/nbstore/src/connection/connection.ts
new file mode 100644
index 0000000000000..68e045eca93b9
--- /dev/null
+++ b/packages/common/nbstore/src/connection/connection.ts
@@ -0,0 +1,132 @@
+import EventEmitter2 from 'eventemitter2';
+
+export type ConnectionStatus =
+  | 'idle'
+  | 'connecting'
+  | 'connected'
+  | 'error'
+  | 'closed';
+
+export abstract class Connection<T = any> {
+  private readonly event = new EventEmitter2();
+  private _inner: T | null = null;
+  private _status: ConnectionStatus = 'idle';
+  protected error?: Error;
+  private refCount = 0;
+
+  constructor() {
+    this.autoReconnect();
+  }
+
+  get shareId(): string | undefined {
+    return undefined;
+  }
+
+  get maybeConnection() {
+    return this._inner;
+  }
+
+  get inner(): T {
+    if (!this._inner) {
+      throw new Error(
+        `Connection ${this.constructor.name} has not been established.`
+      );
+    }
+
+    return this._inner;
+  }
+
+  protected set inner(inner: T | null) {
+    this._inner = inner;
+  }
+
+  get status() {
+    return this._status;
+  }
+
+  protected setStatus(status: ConnectionStatus, error?: Error) {
+    const shouldEmit = status !== this._status && error !== this.error;
+    this._status = status;
+    this.error = error;
+    if (shouldEmit) {
+      this.emitStatusChanged(status, error);
+    }
+  }
+
+  abstract doConnect(): Promise<T>;
+  abstract doDisconnect(conn: T): Promise<void>;
+
+  ref() {
+    this.refCount++;
+  }
+
+  deref() {
+    this.refCount = Math.max(0, this.refCount - 1);
+  }
+
+  async connect() {
+    if (this.status === 'idle' || this.status === 'error') {
+      this.setStatus('connecting');
+      try {
+        this._inner = await this.doConnect();
+        this.setStatus('connected');
+      } catch (error) {
+        this.setStatus('error', error as any);
+      }
+    }
+  }
+
+  async disconnect() {
+    this.deref();
+    if (this.refCount > 0) {
+      return;
+    }
+
+    if (this.status === 'connected') {
+      try {
+        if (this._inner) {
+          await this.doDisconnect(this._inner);
+          this._inner = null;
+        }
+        this.setStatus('closed');
+      } catch (error) {
+        this.setStatus('error', error as any);
+      }
+    }
+  }
+
+  private autoReconnect() {
+    // TODO:
+    //   - maximum retry count
+    //   - dynamic sleep time (attempt < 3 ? 1s : 1min)?
+    this.onStatusChanged(() => {
+      this.connect().catch(() => {});
+    });
+  }
+
+  onStatusChanged(
+    cb: (status: ConnectionStatus, error?: Error) => void
+  ): () => void {
+    this.event.on('statusChanged', cb);
+    return () => {
+      this.event.off('statusChanged', cb);
+    };
+  }
+
+  private readonly emitStatusChanged = (
+    status: ConnectionStatus,
+    error?: Error
+  ) => {
+    this.event.emit('statusChanged', status, error);
+  };
+}
+
+export class DummyConnection extends Connection<undefined> {
+  doConnect() {
+    return Promise.resolve(undefined);
+  }
+
+  doDisconnect() {
+    return Promise.resolve(undefined);
+  }
+}
diff --git a/packages/common/nbstore/src/connection/index.ts b/packages/common/nbstore/src/connection/index.ts
new file mode 100644
index 0000000000000..88ffcbb205efd
--- /dev/null
+++ b/packages/common/nbstore/src/connection/index.ts
@@ -0,0 +1,2 @@
+export * from './connection';
+export * from './shared-connection';
diff --git a/packages/common/nbstore/src/connection/shared-connection.ts b/packages/common/nbstore/src/connection/shared-connection.ts
new file mode 100644
index 0000000000000..3ef9e1b165e95
--- /dev/null
+++ b/packages/common/nbstore/src/connection/shared-connection.ts
@@ -0,0 +1,22 @@
+import type { Connection } from './connection';
+
+const CONNECTIONS: Map<string, Connection<any>> = new Map();
+export function share<T extends Connection<any>>(conn: T): T {
+  if (!conn.shareId) {
+    throw new Error(
+      `Connection ${conn.constructor.name} is not shareable.\nIf you want to make it shareable, please override [shareId].`
+    );
+  }
+
+  const existing = CONNECTIONS.get(conn.shareId);
+
+  if (existing) {
+    existing.ref();
+    return existing as T;
+  }
+
+  CONNECTIONS.set(conn.shareId, conn);
+  conn.ref();
+
+  return conn;
+}
diff --git a/packages/common/nbstore/src/index.ts b/packages/common/nbstore/src/index.ts
new file mode 100644
index 0000000000000..db2f6eb6cf459
--- /dev/null
+++ b/packages/common/nbstore/src/index.ts
@@ -0,0 +1,2 @@
+export * from './connection';
+export * from './storage';
diff --git a/packages/common/nbstore/src/storage/blob.ts b/packages/common/nbstore/src/storage/blob.ts
new file mode 100644
index 0000000000000..6cd877a2e0b47
--- /dev/null
+++ b/packages/common/nbstore/src/storage/blob.ts
@@ -0,0 +1,29 @@
+import { Storage, type StorageOptions } from './storage';
+
+export interface BlobStorageOptions extends StorageOptions {}
+
+export interface BlobRecord {
+  key: string;
+  data: Uint8Array;
+  mime: string;
+  createdAt: Date;
+}
+
+export interface ListedBlobRecord {
+  key: string;
+  mime: string;
+  size: number;
+  createdAt: Date;
+}
+
+export abstract class BlobStorage<
+  Options extends BlobStorageOptions = BlobStorageOptions,
+> extends Storage<Options> {
+  override readonly storageType = 'blob';
+
+  abstract get(key: string): Promise<BlobRecord | null>;
+  abstract set(blob: BlobRecord): Promise<void>;
+  abstract delete(key: string, permanently: boolean): Promise<void>;
+  abstract release(): Promise<void>;
+  abstract list(): Promise<ListedBlobRecord[]>;
+}
diff --git a/packages/common/nbstore/src/storage/doc.ts b/packages/common/nbstore/src/storage/doc.ts
new file mode 100644
index 0000000000000..876ffad53dffc
--- /dev/null
+++ b/packages/common/nbstore/src/storage/doc.ts
@@ -0,0 +1,258 @@
+import EventEmitter2 from 'eventemitter2';
+import { diffUpdate, encodeStateVectorFromUpdate, mergeUpdates } from 'yjs';
+
+import type { Lock } from './lock';
+import { SingletonLocker } from './lock';
+import { Storage, type StorageOptions } from './storage';
+
+export interface DocClock {
+  docId: string;
+  timestamp: Date;
+}
+
+export type DocClocks = Record<string, Date>;
+export interface DocRecord extends DocClock {
+  bin: Uint8Array;
+  editor?: string;
+}
+
+export interface DocDiff extends DocClock {
+  missing: Uint8Array;
+  state: Uint8Array;
+}
+
+export interface DocUpdate {
+  docId: string;
+  bin: Uint8Array;
+  editor?: string;
+}
+
+export interface Editor {
+  name: string;
+  avatarUrl: string | null;
+}
+
+export interface DocStorageOptions extends StorageOptions {
+  mergeUpdates?: (updates: Uint8Array[]) => Promise<Uint8Array> | Uint8Array;
+}
+
+export abstract class DocStorage<
+  Opts extends DocStorageOptions = DocStorageOptions,
+> extends Storage<Opts> {
+  private readonly event = new EventEmitter2();
+  override readonly storageType = 'doc';
+  private readonly locker = new SingletonLocker();
+
+  /**
+   * Tell a binary is empty yjs binary or not.
+   *
+   * NOTE:
+   *   `[0, 0]` is empty yjs update binary
+   *   `[0]` is empty yjs state vector binary
+   */
+  isEmptyBin(bin: Uint8Array): boolean {
+    return (
+      bin.length === 0 ||
+      // 0x0 for state vector
+      (bin.length === 1 && bin[0] === 0) ||
+      // 0x00 for update
+      (bin.length === 2 && bin[0] === 0 && bin[1] === 0)
+    );
+  }
+
+  // REGION: open apis by Op system
+  /**
+   * Get a doc record with latest binary.
+   */
+  async getDoc(docId: string) {
+    await using _lock = await this.lockDocForUpdate(docId);
+
+    const snapshot = await this.getDocSnapshot(docId);
+    const updates = await this.getDocUpdates(docId);
+
+    if (updates.length) {
+      const { timestamp, bin, editor } = await this.squash(
+        snapshot ? [snapshot, ...updates] : updates
+      );
+
+      const newSnapshot = {
+        spaceId: this.spaceId,
+        docId,
+        bin,
+        timestamp,
+        editor,
+      };
+
+      await this.setDocSnapshot(newSnapshot, snapshot);
+
+      // always mark updates as merged unless throws
+      await this.markUpdatesMerged(docId, updates);
+
+      return newSnapshot;
+    }
+
+    return snapshot;
+  }
+
+  /**
+   * Get a yjs binary diff with the given state vector.
+   */
+  async getDocDiff(docId: string, state?: Uint8Array) {
+    const doc = await this.getDoc(docId);
+
+    if (!doc) {
+      return null;
+    }
+
+    return {
+      docId,
+      missing: state ? diffUpdate(doc.bin, state) : doc.bin,
+      state: encodeStateVectorFromUpdate(doc.bin),
+      timestamp: doc.timestamp,
+    };
+  }
+
+  /**
+   * Push updates into storage
+   */
+  abstract pushDocUpdate(update: DocUpdate): Promise<DocClock>;
+
+  /**
+   * Get all docs timestamps info. especially for useful in sync process.
+   */
+  abstract getDocTimestamps(after?: Date): Promise<DocClocks>;
+
+  /**
+   * Delete a specific doc data with all snapshots and updates
+   */
+  abstract deleteDoc(docId: string): Promise<void>;
+
+  /**
+   * Subscribe on doc updates emitted from storage itself.
+   *
+   * NOTE:
+   *
+   *   There is not always update emitted from storage itself.
+   *
+   *   For example, in Sqlite storage, the update will only come from user's updating on docs,
+   *   in other words, the update will never somehow auto generated in storage internally.
+   *
+   *   But for Cloud storage, there will be updates broadcasted from other clients,
+   *   so the storage will emit updates to notify the client to integrate them.
+   */
+  subscribeDocUpdate(callback: (update: DocRecord) => void) {
+    this.event.on('update', callback);
+
+    return () => {
+      this.event.off('update', callback);
+    };
+  }
+  // ENDREGION
+
+  // REGION: api for internal usage
+  protected on(
+    event: 'update',
+    callback: (update: DocRecord) => void
+  ): () => void;
+  protected on(
+    event: 'snapshot',
+    callback: (snapshot: DocRecord, prevSnapshot: DocRecord | null) => void
+  ): () => void;
+  protected on(event: string, callback: (...args: any[]) => void): () => void {
+    this.event.on(event, callback);
+    return () => {
+      this.event.off(event, callback);
+    };
+  }
+
+  protected emit(event: 'update', update: DocRecord): void;
+  protected emit(
+    event: 'snapshot',
+    snapshot: DocRecord,
+    prevSnapshot: DocRecord | null
+  ): void;
+  protected emit(event: string, ...args: any[]): void {
+    this.event.emit(event, ...args);
+  }
+
+  protected off(event: string, callback: (...args: any[]) => void): void {
+    this.event.off(event, callback);
+  }
+
+  /**
+   * Get a doc snapshot from storage
+   */
+  protected abstract getDocSnapshot(docId: string): Promise<DocRecord | null>;
+  /**
+   * Set the doc snapshot into storage
+   *
+   * @safety
+   * be careful when implementing this method.
+   *
+   * It might be called with outdated snapshot when running in multi-thread environment.
+   *
+   * A common solution is update the snapshot record is DB only when the coming one's timestamp is newer.
+   *
+   * @example
+   * ```ts
+   * await using _lock = await this.lockDocForUpdate(docId);
+   * // set snapshot
+   *
+   * ```
+   */
+  protected abstract setDocSnapshot(
+    snapshot: DocRecord,
+    prevSnapshot: DocRecord | null
+  ): Promise<boolean>;
+
+  /**
+   * Get all updates of a doc that haven't been merged into snapshot.
+   *
+   * Updates queue design exists for a performace concern:
+   * A huge amount of write time will be saved if we don't merge updates into snapshot immediately.
+   * Updates will be merged into snapshot when the latest doc is requested.
+   */
+  protected abstract getDocUpdates(docId: string): Promise<DocRecord[]>;
+
+  /**
+   * Mark updates as merged into snapshot.
+   */
+  protected abstract markUpdatesMerged(
+    docId: string,
+    updates: DocRecord[]
+  ): Promise<number>;
+
+  /**
+   * Merge doc updates into a single update.
+   */
+  protected async squash(updates: DocRecord[]): Promise<DocRecord> {
+    const lastUpdate = updates.at(-1);
+    if (!lastUpdate) {
+      throw new Error('No updates to be squashed.');
+    }
+
+    // fast return
+    if (updates.length === 1) {
+      return lastUpdate;
+    }
+
+    const finalUpdate = await this.mergeUpdates(updates.map(u => u.bin));
+
+    return {
+      docId: lastUpdate.docId,
+      bin: finalUpdate,
+      timestamp: lastUpdate.timestamp,
+      editor: lastUpdate.editor,
+    };
+  }
+
+  protected mergeUpdates(updates: Uint8Array[]) {
+    const merge = this.options?.mergeUpdates ?? mergeUpdates;
+
+    return merge(updates.filter(bin => !this.isEmptyBin(bin)));
+  }
+
+  protected async lockDocForUpdate(docId: string): Promise<Lock> {
+    return this.locker.lock(`workspace:${this.spaceId}:update`, docId);
+  }
+}
diff --git a/packages/common/nbstore/src/storage/history.ts b/packages/common/nbstore/src/storage/history.ts
new file mode 100644
index 0000000000000..4f7d52c4f3571
--- /dev/null
+++ b/packages/common/nbstore/src/storage/history.ts
@@ -0,0 +1,122 @@
+import { noop } from 'lodash-es';
+import {
+  applyUpdate,
+  Doc,
+  encodeStateAsUpdate,
+  encodeStateVector,
+  UndoManager,
+} from 'yjs';
+
+import { type DocRecord, DocStorage, type DocStorageOptions } from './doc';
+
+export interface HistoryFilter {
+  before?: Date;
+  limit?: Date;
+}
+
+export interface ListedHistory {
+  userId: string | null;
+  timestamp: Date;
+}
+
+export abstract class HistoricalDocStorage<
+  Options extends DocStorageOptions = DocStorageOptions,
+> extends DocStorage<Options> {
+  constructor(opts: Options) {
+    super(opts);
+
+    this.on('snapshot', snapshot => {
+      this.createHistory(snapshot.docId, snapshot).catch(noop);
+    });
+  }
+
+  override async setDocSnapshot(
+    snapshot: DocRecord,
+    prevSnapshot: DocRecord | null
+  ): Promise<boolean> {
+    const success = await this.upsertDocSnapshot(snapshot, prevSnapshot);
+    if (success) {
+      this.emit('snapshot', snapshot, prevSnapshot);
+    }
+    return success;
+  }
+
+  /**
+   * Update the doc snapshot in storage or create a new one if not exists.
+   *
+   * @safety
+   * be careful when implementing this method.
+   *
+   * It might be called with outdated snapshot when running in multi-thread environment.
+   *
+   * A common solution is update the snapshot record is DB only when the coming one's timestamp is newer.
+   *
+   * @example
+   * ```ts
+   * await using _lock = await this.lockDocForUpdate(docId);
+   * // set snapshot
+   *
+   * ```
+   */
+  abstract upsertDocSnapshot(
+    snapshot: DocRecord,
+    prevSnapshot: DocRecord | null
+  ): Promise<boolean>;
+
+  abstract listHistories(
+    docId: string,
+    filter?: HistoryFilter
+  ): Promise<ListedHistory[]>;
+  abstract getHistory(
+    docId: string,
+    timestamp: Date
+  ): Promise<DocRecord | null>;
+  abstract deleteHistory(docId: string, timestamp: Date): Promise<void>;
+
+  async rollbackDoc(docId: string, timestamp: Date, editor?: string) {
+    const toSnapshot = await this.getHistory(docId, timestamp);
+    if (!toSnapshot) {
+      throw new Error('Can not find the version to rollback to.');
+    }
+
+    const fromSnapshot = await this.getDoc(docId);
+
+    if (!fromSnapshot) {
+      throw new Error('Can not find the current version of the doc.');
+    }
+
+    const change = this.generateRevertUpdate(fromSnapshot.bin, toSnapshot.bin);
+    await this.pushDocUpdate({ docId, bin: change, editor });
+    // force create a new history record after rollback
+    await this.createHistory(docId, fromSnapshot);
+  }
+
+  // history can only be created upon update pushing.
+  protected abstract createHistory(
+    docId: string,
+    snapshot: DocRecord
+  ): Promise<void>;
+
+  protected generateRevertUpdate(
+    fromNewerBin: Uint8Array,
+    toOlderBin: Uint8Array
+  ): Uint8Array {
+    const newerDoc = new Doc();
+    applyUpdate(newerDoc, fromNewerBin);
+    const olderDoc = new Doc();
+    applyUpdate(olderDoc, toOlderBin);
+
+    const newerState = encodeStateVector(newerDoc);
+    const olderState = encodeStateVector(olderDoc);
+
+    const diff = encodeStateAsUpdate(newerDoc, olderState);
+
+    const undoManager = new UndoManager(Array.from(olderDoc.share.values()));
+
+    applyUpdate(olderDoc, diff);
+
+    undoManager.undo();
+
+    return encodeStateAsUpdate(olderDoc, newerState);
+  }
+}
diff --git a/packages/common/nbstore/src/storage/index.ts b/packages/common/nbstore/src/storage/index.ts
new file mode 100644
index 0000000000000..220af70e754a1
--- /dev/null
+++ b/packages/common/nbstore/src/storage/index.ts
@@ -0,0 +1,93 @@
+import EventEmitter2 from 'eventemitter2';
+
+import type { ConnectionStatus } from '../connection';
+import { type Storage, type StorageType } from '../storage';
+
+export class SpaceStorage {
+  protected readonly storages: Map<StorageType, Storage> = new Map();
+  private readonly event = new EventEmitter2();
+  private readonly disposables: Set<() => void> = new Set();
+
+  constructor(storages: Storage[] = []) {
+    this.storages = new Map(
+      storages.map(storage => [storage.storageType, storage])
+    );
+  }
+
+  tryGet(type: StorageType) {
+    return this.storages.get(type);
+  }
+
+  get(type: StorageType) {
+    const storage = this.tryGet(type);
+
+    if (!storage) {
+      throw new Error(`Storage ${type} not registered.`);
+    }
+
+    return storage;
+  }
+
+  async connect() {
+    await Promise.allSettled(
+      Array.from(this.storages.values()).map(async storage => {
+        this.disposables.add(
+          storage.connection.onStatusChanged((status, error) => {
+            this.event.emit('connection', {
+              storage: storage.storageType,
+              status,
+              error,
+            });
+          })
+        );
+        await storage.connect();
+      })
+    );
+  }
+
+  async disconnect() {
+    await Promise.allSettled(
+      Array.from(this.storages.values()).map(async storage => {
+        await storage.disconnect();
+      })
+    );
+  }
+
+  on(
+    event: 'connection',
+    cb: (payload: {
+      storage: StorageType;
+      status: ConnectionStatus;
+      error?: Error;
+    }) => void
+  ): () => void {
+    this.event.on(event, cb);
+    return () => {
+      this.event.off(event, cb);
+    };
+  }
+
+  off(
+    event: 'connection',
+    cb: (payload: {
+      storage: StorageType;
+      status: ConnectionStatus;
+      error?: Error;
+    }) => void
+  ): void {
+    this.event.off(event, cb);
+  }
+
+  async destroy() {
+    await this.disconnect();
+    this.disposables.forEach(disposable => disposable());
+    this.event.removeAllListeners();
+    this.storages.clear();
+  }
+}
+
+export * from './blob';
+export * from './doc';
+export * from './history';
+export * from './storage';
+export * from './sync';
diff --git a/packages/common/nbstore/src/storage/lock.ts b/packages/common/nbstore/src/storage/lock.ts
new file mode 100644
index 0000000000000..d83c2dc03ce64
--- /dev/null
+++ b/packages/common/nbstore/src/storage/lock.ts
@@ -0,0 +1,44 @@
+export interface Locker {
+  lock(domain: string, resource: string): Promise<Lock>;
+}
+
+export class SingletonLocker implements Locker {
+  lockedResource = new Map<string, Lock>();
+  constructor() {}
+
+  async lock(domain: string, resource: string) {
+    const key = `${domain}:${resource}`;
+    let lock = this.lockedResource.get(key);
+
+    if (!lock) {
+      lock = new Lock();
+      this.lockedResource.set(key, lock);
+    }
+
+    await lock.acquire();
+
+    return lock;
+  }
+}
+
+export class Lock {
+  private inner: Promise<void> = Promise.resolve();
+  private release: () => void = () => {};
+
+  async acquire() {
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    let release: () => void = null!;
+    const nextLock = new Promise<void>(resolve => {
+      release = resolve;
+    });
+
+    await this.inner;
+    this.inner = nextLock;
+    this.release = release;
+  }
+
+  [Symbol.asyncDispose]() {
+    this.release();
+    return Promise.resolve();
+  }
+}
diff --git a/packages/common/nbstore/src/storage/storage.ts b/packages/common/nbstore/src/storage/storage.ts
new file mode 100644
index 0000000000000..bbf6182d58734
--- /dev/null
+++ b/packages/common/nbstore/src/storage/storage.ts
@@ -0,0 +1,37 @@
+import type { Connection } from '../connection';
+
+export type SpaceType = 'workspace' | 'userspace';
+export type StorageType = 'blob' | 'doc' | 'sync';
+
+export interface StorageOptions {
+  peer: string;
+  type: SpaceType;
+  id: string;
+}
+
+export abstract class Storage<Opts extends StorageOptions = StorageOptions> {
+  abstract readonly storageType: StorageType;
+  abstract readonly connection: Connection;
+
+  get peer() {
+    return this.options.peer;
+  }
+
+  get spaceType() {
+    return this.options.type;
+  }
+
+  get spaceId() {
+    return this.options.id;
+  }
+
+  constructor(public readonly options: Opts) {}
+
+  async connect() {
+    await this.connection.connect();
+  }
+
+  async disconnect() {
+    await this.connection.disconnect();
+  }
+}
diff --git a/packages/common/nbstore/src/storage/sync.ts b/packages/common/nbstore/src/storage/sync.ts
new file mode 100644
index 0000000000000..b2ad2744335de
--- /dev/null
+++ b/packages/common/nbstore/src/storage/sync.ts
@@ -0,0 +1,16 @@
+import type { DocClock, DocClocks } from './doc';
+import { Storage, type StorageOptions } from './storage';
+
+export interface SyncStorageOptions extends StorageOptions {}
+
+export abstract class SyncStorage<
+  Opts extends SyncStorageOptions = SyncStorageOptions,
+> extends Storage<Opts> {
+  override readonly storageType = 'sync';
+
+  abstract getPeerClocks(peer: string): Promise<DocClocks>;
+  abstract setPeerClock(peer: string, clock: DocClock): Promise<void>;
+  abstract getPeerPushedClocks(peer: string): Promise<DocClocks>;
+  abstract setPeerPushedClock(peer: string, clock: DocClock): Promise<void>;
+  abstract clearClocks(): Promise<void>;
+}
diff --git a/packages/common/nbstore/tsconfig.json b/packages/common/nbstore/tsconfig.json
new file mode 100644
index 0000000000000..e5276f5627270
--- /dev/null
+++ b/packages/common/nbstore/tsconfig.json
@@ -0,0 +1,20 @@
+{
+  "extends": "../../../tsconfig.json",
+  "include": ["./src"],
+  "compilerOptions": {
+    "composite": true,
+    "noEmit": false,
+    "outDir": "lib"
+  },
+  "references": [
+    {
+      "path": "../../frontend/graphql"
+    },
+    {
+      "path": "../../frontend/electron-api"
+    },
+    {
+      "path": "../infra"
+    }
+  ]
+}
diff --git a/tools/commitlint/.commitlintrc.json b/tools/commitlint/.commitlintrc.json
index 2240b41237b4a..e3ef1467c514a 100644
--- a/tools/commitlint/.commitlintrc.json
+++ b/tools/commitlint/.commitlintrc.json
@@ -25,7 +25,7 @@
         "native",
         "templates",
         "debug",
-        "storage",
+        "nbstore",
         "infra"
       ]
     ]
diff --git a/tsconfig.json b/tsconfig.json
index d5872013e8f85..17a68dee4a50d 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -72,7 +72,8 @@
       "@affine/native/*": ["./packages/frontend/native/*"],
       "@affine/server-native": ["./packages/backend/native/index.d.ts"],
       // Development only
-      "@affine/electron/*": ["./packages/frontend/apps/electron/src/*"]
+      "@affine/electron/*": ["./packages/frontend/apps/electron/src/*"],
+      "@affine/nbstore": ["./packages/common/nbstore/src"]
     }
   },
   "include": [],
@@ -131,6 +132,9 @@
     {
       "path": "./packages/common/infra"
     },
+    {
+      "path": "./packages/common/nbstore"
+    },
     // Tools
     {
       "path": "./tools/cli"
diff --git a/yarn.lock b/yarn.lock
index c348956a9e56a..d4be8065aea03 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -723,6 +723,18 @@ __metadata:
   languageName: unknown
   linkType: soft
 
+"@affine/nbstore@workspace:packages/common/nbstore":
+  version: 0.0.0-use.local
+  resolution: "@affine/nbstore@workspace:packages/common/nbstore"
+  dependencies:
+    "@toeverything/infra": "workspace:*"
+    eventemitter2: "npm:^6.4.9"
+    lodash-es: "npm:^4.17.21"
+    rxjs: "npm:^7.8.1"
+    yjs: "patch:yjs@npm%3A13.6.18#~/.yarn/patches/yjs-npm-13.6.18-ad0d5f7c43.patch"
+  languageName: unknown
+  linkType: soft
+
 "@affine/playstore-auto-bump@workspace:tools/playstore-auto-bump":
   version: 0.0.0-use.local
   resolution: "@affine/playstore-auto-bump@workspace:tools/playstore-auto-bump"