diff --git a/packages/core/src/__tests__/client.test.ts b/packages/core/src/__tests__/client.test.ts
index d22405c96e..21173e041b 100644
--- a/packages/core/src/__tests__/client.test.ts
+++ b/packages/core/src/__tests__/client.test.ts
@@ -14,10 +14,10 @@
 // limitations under the License.
 //
 import { IntlString, Plugin } from '@hcengineering/platform'
+import { ClientConnectEvent, DocChunk } from '..'
 import type { Account, Class, Data, Doc, Domain, PluginConfiguration, Ref, Timestamp } from '../classes'
 import { ClassifierKind, DOMAIN_MODEL, Space } from '../classes'
 import { ClientConnection, createClient } from '../client'
-import { clone } from '../clone'
 import core from '../component'
 import { Hierarchy } from '../hierarchy'
 import { ModelDb, TxDb } from '../memdb'
@@ -103,38 +103,62 @@ describe('client', () => {
         return await transactions.findAll(_class, query)
       }
 
-      return {
-        isConnected: () => true,
-        findAll,
+      return new (class implements ClientConnection {
+        handler?: (event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>
 
-        searchFulltext: async (query: SearchQuery, options: SearchOptions): Promise<SearchResult> => {
+        set onConnect (
+          handler: ((event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>) | undefined
+        ) {
+          this.handler = handler
+          void this.handler?.(ClientConnectEvent.Connected, '', {})
+        }
+
+        get onConnect ():
+        | ((event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>)
+        | undefined {
+          return this.handler
+        }
+
+        isConnected = (): boolean => true
+        findAll = findAll
+
+        searchFulltext = async (query: SearchQuery, options: SearchOptions): Promise<SearchResult> => {
           return { docs: [] }
-        },
+        }
 
-        tx: async (tx: Tx): Promise<TxResult> => {
+        tx = async (tx: Tx): Promise<TxResult> => {
           if (tx.objectSpace === core.space.Model) {
             hierarchy.tx(tx)
           }
           const result = await Promise.all([transactions.tx(tx)])
           return result[0]
-        },
-        close: async () => {},
+        }
+
+        close = async (): Promise<void> => {}
 
-        loadChunk: async (domain: Domain, idx?: number) => ({
+        loadChunk = async (domain: Domain, idx?: number): Promise<DocChunk> => ({
           idx: -1,
-          index: -1,
           docs: [],
-          finished: true,
-          digest: ''
-        }),
-        closeChunk: async (idx: number) => {},
-        loadDocs: async (domain: Domain, docs: Ref<Doc>[]) => [],
-        upload: async (domain: Domain, docs: Doc[]) => {},
-        clean: async (domain: Domain, docs: Ref<Doc>[]) => {},
-        loadModel: async (last: Timestamp) => clone(txes),
-        getAccount: async () => null as unknown as Account,
-        sendForceClose: async () => {}
-      }
+          finished: true
+        })
+
+        async closeChunk (idx: number): Promise<void> {}
+        async loadDocs (domain: Domain, docs: Ref<Doc>[]): Promise<Doc[]> {
+          return []
+        }
+
+        async upload (domain: Domain, docs: Doc[]): Promise<void> {}
+        async clean (domain: Domain, docs: Ref<Doc>[]): Promise<void> {}
+        async loadModel (last: Timestamp): Promise<Tx[]> {
+          return txes
+        }
+
+        async getAccount (): Promise<Account> {
+          return null as unknown as Account
+        }
+
+        async sendForceClose (): Promise<void> {}
+      })()
     }
     const spyCreate = jest.spyOn(TxProcessor, 'createDoc2Doc')
     const spyUpdate = jest.spyOn(TxProcessor, 'updateDoc2Doc')
diff --git a/packages/core/src/__tests__/connection.ts b/packages/core/src/__tests__/connection.ts
index 17b549e10d..84570e22cf 100644
--- a/packages/core/src/__tests__/connection.ts
+++ b/packages/core/src/__tests__/connection.ts
@@ -13,12 +13,13 @@
 // limitations under the License.
 //
 
+import { ClientConnectEvent, DocChunk } from '..'
 import type { Account, Class, Doc, Domain, Ref, Timestamp } from '../classes'
 import { ClientConnection } from '../client'
 import core from '../component'
 import { Hierarchy } from '../hierarchy'
 import { ModelDb, TxDb } from '../memdb'
-import type { DocumentQuery, FindResult, TxResult, SearchQuery, SearchOptions, SearchResult } from '../storage'
+import type { DocumentQuery, FindResult, SearchOptions, SearchQuery, SearchResult, TxResult } from '../storage'
 import type { Tx } from '../tx'
 import { DOMAIN_TX } from '../tx'
 import { genMinModel } from './minmodel'
@@ -42,37 +43,62 @@ export async function connect (handler: (tx: Tx) => void): Promise<ClientConnect
     return await model.findAll(_class, query)
   }
 
-  return {
-    isConnected: () => true,
-    findAll,
+  class ClientConnectionImpl implements ClientConnection {
+    isConnected = (): boolean => true
+    findAll = findAll
 
-    searchFulltext: async (query: SearchQuery, options: SearchOptions): Promise<SearchResult> => {
+    handler?: (event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>
+
+    set onConnect (
+      handler: ((event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>) | undefined
+    ) {
+      this.handler = handler
+      void this.handler?.(ClientConnectEvent.Connected, '', {})
+    }
+
+    get onConnect (): ((event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>) | undefined {
+      return this.handler
+    }
+
+    async searchFulltext (query: SearchQuery, options: SearchOptions): Promise<SearchResult> {
       return { docs: [] }
-    },
+    }
 
-    tx: async (tx: Tx): Promise<TxResult> => {
+    async tx (tx: Tx): Promise<TxResult> {
       if (tx.objectSpace === core.space.Model) {
         hierarchy.tx(tx)
       }
       const result = await Promise.all([model.tx(tx), transactions.tx(tx)])
       return result[0]
-      // handler(tx) - we have only one client, should not update?
-    },
-    close: async () => {},
-
-    loadChunk: async (domain: Domain, idx?: number) => ({
-      idx: -1,
-      index: -1,
-      docs: [],
-      finished: true,
-      digest: ''
-    }),
-    closeChunk: async (idx: number) => {},
-    loadDocs: async (domain: Domain, docs: Ref<Doc>[]) => [],
-    upload: async (domain: Domain, docs: Doc[]) => {},
-    clean: async (domain: Domain, docs: Ref<Doc>[]) => {},
-    loadModel: async (last: Timestamp) => txes,
-    getAccount: async () => null as unknown as Account,
-    sendForceClose: async () => {}
+    }
+
+    async close (): Promise<void> {}
+
+    async loadChunk (domain: Domain, idx?: number): Promise<DocChunk> {
+      return {
+        idx: -1,
+        docs: [],
+        finished: true
+      }
+    }
+
+    async closeChunk (idx: number): Promise<void> {}
+    async loadDocs (domain: Domain, docs: Ref<Doc>[]): Promise<Doc[]> {
+      return []
+    }
+
+    async upload (domain: Domain, docs: Doc[]): Promise<void> {}
+    async clean (domain: Domain, docs: Ref<Doc>[]): Promise<void> {}
+    async loadModel (last: Timestamp): Promise<Tx[]> {
+      return txes
+    }
+
+    async getAccount (): Promise<Account> {
+      return null as unknown as Account
+    }
+
+    async sendForceClose (): Promise<void> {}
   }
+
+  return new ClientConnectionImpl()
 }
diff --git a/packages/core/src/client.ts b/packages/core/src/client.ts
index 0f9e9e4849..e3f009213b 100644
--- a/packages/core/src/client.ts
+++ b/packages/core/src/client.ts
@@ -254,12 +254,9 @@ export async function createClient (
       }
     }
   }
+  let initialized = false
   const conn = await ctx.with('connect', {}, () => connect(txHandler))
 
-  await ctx.with('load-model', { reload: false }, (ctx) =>
-    loadModel(ctx, conn, modelFilter, hierarchy, model, false, txPersistence)
-  )
-
   txBuffer = txBuffer.filter((tx) => tx.space !== core.space.Model)
 
   client = new ClientImpl(conn)
@@ -271,56 +268,92 @@ export async function createClient (
   const oldOnConnect:
   | ((event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>)
   | undefined = conn.onConnect
-  conn.onConnect = async (event, _lastTx, data) => {
-    console.log('Client: onConnect', event)
-    if (event === ClientConnectEvent.Maintenance) {
-      lastTx = _lastTx
-      await oldOnConnect?.(ClientConnectEvent.Maintenance, _lastTx, data)
-      return
-    }
-    // Find all new transactions and apply
-    const loadModelResponse = await ctx.with('connect', { reload: true }, (ctx) =>
-      loadModel(ctx, conn, modelFilter, hierarchy, model, true, txPersistence)
-    )
-
-    if (event === ClientConnectEvent.Reconnected && loadModelResponse.full) {
-      // We have upgrade procedure and need rebuild all stuff.
-      hierarchy = new Hierarchy()
-      model = new ModelDb(hierarchy)
 
-      await ctx.with('build-model', {}, (ctx) => buildModel(ctx, loadModelResponse, modelFilter, hierarchy, model))
-      await oldOnConnect?.(ClientConnectEvent.Upgraded, _lastTx, data)
-      lastTx = _lastTx
-      // No need to fetch more stuff since upgrade was happened.
-      return
-    }
+  await new Promise<void>((resolve) => {
+    conn.onConnect = async (event, _lastTx, data) => {
+      console.log('Client: onConnect', event)
+      if (event === ClientConnectEvent.Maintenance) {
+        lastTx = _lastTx
+        await oldOnConnect?.(ClientConnectEvent.Maintenance, _lastTx, data)
+        return
+      }
+      // Find all new transactions and apply
+      const { mode, current, addition } = await ctx.with('load-model', {}, (ctx) => loadModel(ctx, conn, txPersistence))
+      if (!initialized) {
+        switch (mode) {
+          case 'same':
+          case 'upgrade':
+            await ctx.with('build-model', {}, (ctx) => buildModel(ctx, current, modelFilter, hierarchy, model))
+            break
+          case 'addition':
+            await ctx.with('build-model', {}, (ctx) =>
+              buildModel(ctx, current.concat(addition), modelFilter, hierarchy, model)
+            )
+        }
+        initialized = true
+      } else {
+        switch (mode) {
+          case 'upgrade':
+            // We have upgrade procedure and need rebuild all stuff.
+            hierarchy = new Hierarchy()
+            model = new ModelDb(hierarchy)
+            ;(client as ClientImpl).setModel(hierarchy, model)
+
+            await ctx.with('build-model', {}, (ctx) => buildModel(ctx, current, modelFilter, hierarchy, model))
+            await oldOnConnect?.(ClientConnectEvent.Upgraded, _lastTx, data)
+            // No need to fetch more stuff since upgrade was happened.
+            break
+          case 'addition':
+            await ctx.with('build-model', {}, (ctx) =>
+              buildModel(ctx, current.concat(addition), modelFilter, hierarchy, model)
+            )
+            break
+        }
+      }
+      resolve()
+
+      if (lastTx === undefined) {
+        // No need to do anything here since we connected.
+        await oldOnConnect?.(event, _lastTx, data)
+        lastTx = _lastTx
+        resolve()
+        return
+      }
 
-    if (event === ClientConnectEvent.Connected && _lastTx !== lastTx && lastTx === undefined) {
-      // No need to do anything here since we connected.
-      await oldOnConnect?.(event, _lastTx, data)
+      if (lastTx === _lastTx) {
+        // Same lastTx, no need to refresh
+        await oldOnConnect?.(ClientConnectEvent.Reconnected, _lastTx, data)
+        resolve()
+        return
+      }
       lastTx = _lastTx
-      return
-    }
-
-    if (_lastTx === lastTx) {
-      // Same lastTx, no need to refresh
-      await oldOnConnect?.(ClientConnectEvent.Reconnected, _lastTx, data)
-      return
+      // We need to trigger full refresh on queries, etc.
+      await oldOnConnect?.(ClientConnectEvent.Refresh, lastTx, data)
+      resolve()
     }
-    lastTx = _lastTx
-    // We need to trigger full refresh on queries, etc.
-    await oldOnConnect?.(ClientConnectEvent.Refresh, lastTx, data)
-  }
+  })
 
   return client
 }
 
-async function tryLoadModel (
+// Ignore Employee accounts.
+function isPersonAccount (tx: Tx): boolean {
+  return (
+    (tx._class === core.class.TxCreateDoc ||
+      tx._class === core.class.TxUpdateDoc ||
+      tx._class === core.class.TxRemoveDoc) &&
+    ((tx as TxCUD<Doc>).objectClass === 'contact:class:PersonAccount' ||
+      (tx as TxCUD<Doc>).objectClass === 'core:class:Account')
+  )
+}
+
+async function loadModel (
   ctx: MeasureContext,
   conn: ClientConnection,
-  reload: boolean,
   persistence?: TxPersistenceStore
-): Promise<LoadModelResponse> {
+): Promise<{ mode: 'same' | 'addition' | 'upgrade', current: Tx[], addition: Tx[] }> {
+  const t = Date.now()
+
   const current = (await ctx.with('persistence-load', {}, () => persistence?.load())) ?? {
     full: true,
     transactions: [],
@@ -329,8 +362,7 @@ async function tryLoadModel (
 
   if (conn.getLastHash !== undefined && (await conn.getLastHash(ctx)) === current.hash) {
     // We have same model hash.
-    current.full = false // Since we load, no need to send full
-    return current
+    return { mode: 'same', current: current.transactions, addition: [] }
   }
   const lastTxTime = getLastTxTime(current.transactions)
   const result = await ctx.with('connection-load-model', { hash: current.hash !== '' }, (ctx) =>
@@ -340,78 +372,37 @@ async function tryLoadModel (
   if (Array.isArray(result)) {
     // Fallback to old behavior, only for tests
     return {
-      full: true,
-      transactions: result,
-      hash: ''
+      mode: 'same',
+      current: result,
+      addition: []
     }
   }
-  const transactions = current.transactions.concat(result.transactions)
-  if (result.hash !== current.hash) {
-    // Save concatenated, if have some more of them.
-    void ctx
-      .with('persistence-store', {}, (ctx) =>
-        persistence?.store({
-          ...result,
-          transactions: !result.full ? transactions : result.transactions
-        })
-      )
-      .catch((err) => {
-        Analytics.handleError(err)
-      })
-  }
-
-  if (!result.full && !reload) {
-    result.transactions = transactions
-  }
-
-  return result
-}
-
-// Ignore Employee accounts.
-function isPersonAccount (tx: Tx): boolean {
-  return (
-    (tx._class === core.class.TxCreateDoc ||
-      tx._class === core.class.TxUpdateDoc ||
-      tx._class === core.class.TxRemoveDoc) &&
-    ((tx as TxCUD<Doc>).objectClass === 'contact:class:PersonAccount' ||
-      (tx as TxCUD<Doc>).objectClass === 'core:class:Account')
-  )
-}
 
-async function loadModel (
-  ctx: MeasureContext,
-  conn: ClientConnection,
-  modelFilter: ModelFilter | undefined,
-  hierarchy: Hierarchy,
-  model: ModelDb,
-  reload = false,
-  persistence?: TxPersistenceStore
-): Promise<LoadModelResponse> {
-  const t = Date.now()
-
-  const modelResponse = await ctx.with('try-load-model', { reload }, (ctx) =>
-    tryLoadModel(ctx, conn, reload, persistence)
-  )
-
-  if (reload && modelResponse.full) {
-    return modelResponse
-  }
+  // Save concatenated, if have some more of them.
+  void ctx
+    .with('persistence-store', {}, (ctx) =>
+      persistence?.store({
+        ...result,
+        // Store concatinated old + new txes
+        transactions: result.full ? result.transactions : current.transactions.concat(result.transactions)
+      })
+    )
+    .catch((err) => {
+      Analytics.handleError(err)
+    })
 
   if (typeof window !== 'undefined') {
-    console.log(
-      'find' + (modelResponse.full ? 'full model' : 'model diff'),
-      modelResponse.transactions.length,
-      Date.now() - t
-    )
+    console.log('find' + (result.full ? 'full model' : 'model diff'), result.transactions.length, Date.now() - t)
   }
-
-  await ctx.with('build-model', {}, (ctx) => buildModel(ctx, modelResponse, modelFilter, hierarchy, model))
-  return modelResponse
+  if (result.full) {
+    return { mode: 'upgrade', current: result.transactions, addition: [] }
+  }
+  return { mode: 'addition', current: current.transactions, addition: result.transactions }
 }
 
 async function buildModel (
   ctx: MeasureContext,
-  modelResponse: LoadModelResponse,
+  transactions: Tx[],
   modelFilter: ModelFilter | undefined,
   hierarchy: Hierarchy,
   model: ModelDb
@@ -419,7 +410,7 @@ async function buildModel (
   const systemTx: Tx[] = []
   const userTx: Tx[] = []
 
-  const atxes = modelResponse.transactions
+  const atxes = transactions
 
   ctx.withSync('split txes', {}, () => {
     atxes.forEach((tx) =>
diff --git a/packages/query/src/__tests__/connection.ts b/packages/query/src/__tests__/connection.ts
index 3cb9a5c4a6..6c41e0cd76 100644
--- a/packages/query/src/__tests__/connection.ts
+++ b/packages/query/src/__tests__/connection.ts
@@ -13,26 +13,33 @@
 // limitations under the License.
 //
 
-import type {
+import core, {
+  Account,
   AccountClient,
   BackupClient,
   Class,
+  ClientConnectEvent,
+  ClientConnection,
   Doc,
+  DocChunk,
   DocumentQuery,
   Domain,
+  DOMAIN_TX,
   FindOptions,
   FindResult,
+  FulltextStorage,
+  Hierarchy,
   LoadModelResponse,
+  ModelDb,
   Ref,
+  SearchOptions,
+  SearchQuery,
+  SearchResult,
   Timestamp,
   Tx,
-  TxResult,
-  FulltextStorage,
-  SearchQuery,
-  SearchOptions,
-  SearchResult
+  TxDb,
+  TxResult
 } from '@hcengineering/core'
-import core, { DOMAIN_TX, Hierarchy, ModelDb, TxDb } from '@hcengineering/core'
 import { genMinModel } from './minmodel'
 
 export async function connect (handler: (tx: Tx) => void): Promise<
@@ -55,49 +62,103 @@ FulltextStorage & {
     await model.tx(tx)
   }
 
-  async function findAll<T extends Doc> (
-    _class: Ref<Class<T>>,
-    query: DocumentQuery<T>,
-    options?: FindOptions<T>
-  ): Promise<FindResult<T>> {
-    const domain = hierarchy.getClass(_class).domain
-    if (domain === DOMAIN_TX) return await transactions.findAll(_class, query, options)
-    return await model.findAll(_class, query, options)
-  }
+  class TestConnection implements ClientConnection {
+    private readonly hierarchy: Hierarchy
+    private readonly model: ModelDb
+    private readonly transactions: TxDb
+
+    constructor (hierarchy: Hierarchy, model: ModelDb, transactions: TxDb) {
+      this.hierarchy = hierarchy
+      this.model = model
+      this.transactions = transactions
+    }
+
+    isConnected (): boolean {
+      return true
+    }
+
+    async findAll<T extends Doc>(
+      _class: Ref<Class<T>>,
+      query: DocumentQuery<T>,
+      options?: FindOptions<T>
+    ): Promise<FindResult<T>> {
+      const domain = this.hierarchy.getClass(_class).domain
+      if (domain === DOMAIN_TX) return await this.transactions.findAll(_class, query, options)
+      return await this.model.findAll(_class, query, options)
+    }
+
+    async findOne<T extends Doc>(
+      _class: Ref<Class<T>>,
+      query: DocumentQuery<T>,
+      options?: FindOptions<T>
+    ): Promise<T | undefined> {
+      return (await this.findAll(_class, query, { ...options, limit: 1 })).shift()
+    }
+
+    getHierarchy (): Hierarchy {
+      return this.hierarchy
+    }
+
+    getModel (): ModelDb {
+      return this.model
+    }
+
+    async getAccount (): Promise<Account> {
+      return {} as unknown as any
+    }
 
-  return {
-    isConnected: () => true,
-    findAll,
-    findOne: async (_class, query, options) => (await findAll(_class, query, { ...options, limit: 1 })).shift(),
-    getHierarchy: () => hierarchy,
-    getModel: () => model,
-    getAccount: async () => ({}) as unknown as any,
-    tx: async (tx: Tx): Promise<TxResult> => {
+    async tx (tx: Tx): Promise<TxResult> {
       if (tx.objectSpace === core.space.Model) {
-        hierarchy.tx(tx)
+        this.hierarchy.tx(tx)
       }
-      await Promise.all([model.tx(tx), transactions.tx(tx)])
-      // Not required, since handled in client.
+      await Promise.all([this.model.tx(tx), this.transactions.tx(tx)])
       handler(tx)
       return {}
-    },
-    close: async () => {},
-    loadChunk: async (domain: Domain, idx?: number) => ({
-      idx: -1,
-      index: -1,
-      docs: [],
-      finished: true,
-      digest: ''
-    }),
-    loadModel: async (lastTxTime) => txes,
-    closeChunk: async (idx: number) => {},
-    loadDocs: async (domain: Domain, docs: Ref<Doc>[]) => [],
-    upload: async (domain: Domain, docs: Doc[]) => {},
-    clean: async (domain: Domain, docs: Ref<Doc>[]) => {},
-
-    searchFulltext: async (query: SearchQuery, options: SearchOptions): Promise<SearchResult> => {
+    }
+
+    async close (): Promise<void> {}
+
+    async loadChunk (domain: Domain, idx?: number): Promise<DocChunk> {
+      return {
+        idx: -1,
+        docs: [],
+        finished: true
+      }
+    }
+
+    async loadModel (lastTxTime: Timestamp): Promise<Tx[]> {
+      return txes
+    }
+
+    async closeChunk (idx: number): Promise<void> {}
+
+    async loadDocs (domain: Domain, docs: Ref<Doc>[]): Promise<Doc[]> {
+      return []
+    }
+
+    async upload (domain: Domain, docs: Doc[]): Promise<void> {}
+
+    async clean (domain: Domain, docs: Ref<Doc>[]): Promise<void> {}
+
+    async searchFulltext (query: SearchQuery, options: SearchOptions): Promise<SearchResult> {
       return { docs: [] }
-    },
-    sendForceClose: async () => {}
+    }
+
+    async sendForceClose (): Promise<void> {}
+
+    handler?: (event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>
+
+    set onConnect (
+      handler: ((event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>) | undefined
+    ) {
+      this.handler = handler
+      void this.handler?.(ClientConnectEvent.Connected, '', {})
+    }
+
+    get onConnect (): ((event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>) | undefined {
+      return this.handler
+    }
   }
+
+  return new TestConnection(hierarchy, model, transactions)
 }
diff --git a/packages/query/src/__tests__/query.test.ts b/packages/query/src/__tests__/query.test.ts
index 517dee02c6..3e19654ecc 100644
--- a/packages/query/src/__tests__/query.test.ts
+++ b/packages/query/src/__tests__/query.test.ts
@@ -984,7 +984,7 @@ describe('query', () => {
   it('test clone ops', async () => {
     const { liveQuery, factory } = await getClient()
 
-    const counter = 10000
+    const counter = 1000
     const ctx = new MeasureMetricsContext('tool', {})
     let data: Space[] = []
     const pp = new Promise((resolve) => {
diff --git a/server/core/src/utils.ts b/server/core/src/utils.ts
index 5fb08a4021..c0f43a2002 100644
--- a/server/core/src/utils.ts
+++ b/server/core/src/utils.ts
@@ -1,5 +1,6 @@
 import core, {
   AccountRole,
+  ClientConnectEvent,
   WorkspaceEvent,
   generateId,
   getTypeOf,
@@ -11,17 +12,27 @@ import core, {
   type BulkUpdateEvent,
   type Class,
   type Client,
+  type ClientConnection,
   type Doc,
+  type DocChunk,
+  type DocumentQuery,
+  type Domain,
+  type FindOptions,
+  type FindResult,
   type MeasureContext,
   type ModelDb,
   type Ref,
+  type SearchResult,
   type SessionData,
+  type Tx,
+  type TxResult,
   type TxWorkspaceEvent,
   type WorkspaceIdWithUrl
 } from '@hcengineering/core'
 import platform, { PlatformError, Severity, Status, unknownError } from '@hcengineering/platform'
 import { type Hash } from 'crypto'
 import fs from 'fs'
+import type { DbAdapter } from './adapter'
 import { BackupClientOps } from './storage'
 import type { Pipeline } from './types'
 
@@ -293,3 +304,65 @@ export function wrapPipeline (
     notify: (...tx) => {}
   }
 }
+
+export function wrapAdapterToClient (ctx: MeasureContext, storageAdapter: DbAdapter, txes: Tx[]): ClientConnection {
+  class TestClientConnection implements ClientConnection {
+    isConnected = (): boolean => true
+
+    handler?: (event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>
+
+    set onConnect (
+      handler: ((event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>) | undefined
+    ) {
+      this.handler = handler
+      void this.handler?.(ClientConnectEvent.Connected, '', {})
+    }
+
+    get onConnect (): ((event: ClientConnectEvent, lastTx: string | undefined, data: any) => Promise<void>) | undefined {
+      return this.handler
+    }
+
+    async findAll<T extends Doc>(
+      _class: Ref<Class<Doc>>,
+      query: DocumentQuery<Doc>,
+      options?: FindOptions<Doc>
+    ): Promise<FindResult<T>> {
+      return (await storageAdapter.findAll(ctx, _class, query, options)) as any
+    }
+
+    async tx (tx: Tx): Promise<TxResult> {
+      return await storageAdapter.tx(ctx, tx)
+    }
+
+    async searchFulltext (): Promise<SearchResult> {
+      return { docs: [] }
+    }
+
+    async close (): Promise<void> {}
+
+    async loadChunk (domain: Domain): Promise<DocChunk> {
+      throw new Error('unsupported')
+    }
+
+    async closeChunk (idx: number): Promise<void> {}
+
+    async loadDocs (domain: Domain, docs: Ref<Doc>[]): Promise<Doc[]> {
+      return []
+    }
+
+    async upload (domain: Domain, docs: Doc[]): Promise<void> {}
+
+    async clean (domain: Domain, docs: Ref<Doc>[]): Promise<void> {}
+
+    async loadModel (): Promise<Tx[]> {
+      return txes
+    }
+
+    async getAccount (): Promise<Account> {
+      return {} as any
+    }
+
+    async sendForceClose (): Promise<void> {}
+  }
+  return new TestClientConnection()
+}
diff --git a/server/mongo/src/__tests__/storage.test.ts b/server/mongo/src/__tests__/storage.test.ts
index 99a408c17a..71216c5a9b 100644
--- a/server/mongo/src/__tests__/storage.test.ts
+++ b/server/mongo/src/__tests__/storage.test.ts
@@ -15,11 +15,7 @@
 //
 import core, {
   type Client,
-  type ClientConnection,
   createClient,
-  type Doc,
-  type DocChunk,
-  type Domain,
   generateId,
   getWorkspaceId,
   Hierarchy,
@@ -30,7 +26,7 @@ import core, {
   type Space,
   TxOperations
 } from '@hcengineering/core'
-import { type DbAdapter } from '@hcengineering/server-core'
+import { type DbAdapter, wrapAdapterToClient } from '@hcengineering/server-core'
 import { createMongoAdapter, createMongoTxAdapter } from '..'
 import { getMongoClient, type MongoClientReference, shutdown } from '../utils'
 import { genMinModel } from './minmodel'
@@ -108,22 +104,7 @@ describe('mongo operations', () => {
     const ctx = new MeasureMetricsContext('client', {})
 
     client = await createClient(async (handler) => {
-      const st: ClientConnection = {
-        isConnected: () => true,
-        findAll: async (_class, query, options) => await serverStorage.findAll(ctx, _class, query, options),
-        tx: async (tx) => await serverStorage.tx(ctx, tx),
-        searchFulltext: async () => ({ docs: [] }),
-        close: async () => {},
-        loadChunk: async (domain): Promise<DocChunk> => await Promise.reject(new Error('unsupported')),
-        closeChunk: async (idx) => {},
-        loadDocs: async (domain: Domain, docs: Ref<Doc>[]) => [],
-        upload: async (domain: Domain, docs: Doc[]) => {},
-        clean: async (domain: Domain, docs: Ref<Doc>[]) => {},
-        loadModel: async () => txes,
-        getAccount: async () => ({}) as any,
-        sendForceClose: async () => {}
-      }
-      return st
+      return wrapAdapterToClient(ctx, serverStorage, txes)
     })
 
     operations = new TxOperations(client, core.account.System)
diff --git a/server/postgres/src/__tests__/storage.test.ts b/server/postgres/src/__tests__/storage.test.ts
index 7b7b5acea2..bc619a440e 100644
--- a/server/postgres/src/__tests__/storage.test.ts
+++ b/server/postgres/src/__tests__/storage.test.ts
@@ -14,11 +14,7 @@
 //
 import core, {
   type Client,
-  type ClientConnection,
   createClient,
-  type Doc,
-  type DocChunk,
-  type Domain,
   generateId,
   getWorkspaceId,
   Hierarchy,
@@ -29,7 +25,7 @@ import core, {
   type Space,
   TxOperations
 } from '@hcengineering/core'
-import { type DbAdapter } from '@hcengineering/server-core'
+import { type DbAdapter, wrapAdapterToClient } from '@hcengineering/server-core'
 import { createPostgresAdapter, createPostgresTxAdapter } from '..'
 import { getDBClient, type PostgresClientReference, shutdown } from '../utils'
 import { genMinModel } from './minmodel'
@@ -121,22 +117,7 @@ describe('postgres operations', () => {
     )
     await serverStorage.init?.(ctx)
     client = await createClient(async (handler) => {
-      const st: ClientConnection = {
-        isConnected: () => true,
-        findAll: async (_class, query, options) => await serverStorage.findAll(ctx, _class, query, options),
-        tx: async (tx) => await serverStorage.tx(ctx, tx),
-        searchFulltext: async () => ({ docs: [] }),
-        close: async () => {},
-        loadChunk: async (domain): Promise<DocChunk> => await Promise.reject(new Error('unsupported')),
-        closeChunk: async (idx) => {},
-        loadDocs: async (domain: Domain, docs: Ref<Doc>[]) => [],
-        upload: async (domain: Domain, docs: Doc[]) => {},
-        clean: async (domain: Domain, docs: Ref<Doc>[]) => {},
-        loadModel: async () => txes,
-        getAccount: async () => ({}) as any,
-        sendForceClose: async () => {}
-      }
-      return st
+      return wrapAdapterToClient(ctx, serverStorage, txes)
     })
 
     operations = new TxOperations(client, core.account.System)