diff --git a/dev/storage/src/storage.ts b/dev/storage/src/storage.ts
index 0c3708807f..3421279af1 100644
--- a/dev/storage/src/storage.ts
+++ b/dev/storage/src/storage.ts
@@ -23,7 +23,7 @@ import type {
   FindOptions
 } from '@anticrm/core'
 import { getResource } from '@anticrm/platform'
-import core, { ModelDb, TxDb, Hierarchy, DOMAIN_TX, DefaultTxFactory } from '@anticrm/core'
+import core, { ModelDb, TxDb, Hierarchy, DOMAIN_TX, TxFactory } from '@anticrm/core'
 
 import * as txJson from './model.tx.json'
 
@@ -40,14 +40,14 @@ export interface ServerStorage {
 }
 
 class DevStorage implements ServerStorage {
-  private readonly txFactory: DefaultTxFactory
+  private readonly txFactory: TxFactory
 
   constructor (
     private readonly hierarchy: Hierarchy,
     private readonly txdb: TxDb,
     private readonly modeldb: ModelDb
   ) {
-    this.txFactory = new DefaultTxFactory(core.account.System)
+    this.txFactory = new TxFactory(core.account.System)
   }
 
   async findAll<T extends Doc> (
diff --git a/packages/core/src/__tests__/minmodel.ts b/packages/core/src/__tests__/minmodel.ts
index c991d66bbc..a9fe2256a6 100644
--- a/packages/core/src/__tests__/minmodel.ts
+++ b/packages/core/src/__tests__/minmodel.ts
@@ -15,43 +15,19 @@
 
 import type { Account, Class, Data, Doc, Domain, Obj, Ref } from '../classes'
 import { ClassifierKind, DOMAIN_MODEL } from '../classes'
-import type { Tx, TxCreateDoc } from '../tx'
+import { Tx, TxCreateDoc, TxFactory } from '../tx'
 import core from '../component'
 import { DOMAIN_TX } from '../tx'
 import { generateId } from '../utils'
 
-export function createClass<T extends Class<Obj>> (_id: Ref<T>, cl: Omit<Data<T>, 'kind'>, domain?: Domain): Tx {
-  const result: TxCreateDoc<Doc> = {
-    _id: generateId(),
-    _class: core.class.TxCreateDoc,
-    objectId: _id,
-    objectClass: core.class.Class,
-    attributes: {
-      kind: ClassifierKind.CLASS,
-      domain: domain ?? DOMAIN_MODEL,
-      ...cl
-    },
-    modifiedBy: 'model' as Ref<Account>,
-    modifiedOn: Date.now(),
-    objectSpace: core.space.Model,
-    space: core.space.Model
-  }
-  return result
+const txFactory = new TxFactory(core.account.System)
+
+function createClass(_class: Ref<Class<Obj>>, attributes: Data<Class<Obj>>) {
+  return txFactory.createTxCreateDoc(core.class.Class, core.space.Model, attributes)
 }
 
-export function createDoc<T extends Doc> (_class: Ref<Class<T>>, attributes: Data<T>): Tx {
-  const tx: TxCreateDoc<T> = {
-    _id: generateId(),
-    _class: core.class.TxCreateDoc,
-    space: core.space.Tx,
-    modifiedBy: core.account.System,
-    modifiedOn: Date.now(),
-    objectId: generateId(),
-    objectClass: _class,
-    objectSpace: core.space.Model,
-    attributes
-  }
-  return tx
+export function createDoc<T extends Doc> (_class: Ref<Class<T>>, attributes: Data<T>) {
+  return txFactory.createTxCreateDoc(_class, core.space.Model, attributes)
 }
 
 /**
@@ -61,16 +37,16 @@ export function createDoc<T extends Doc> (_class: Ref<Class<T>>, attributes: Dat
 export function genMinModel (): Tx[] {
   const txes = []
   // Fill Tx'es with basic model classes.
-  txes.push(createClass(core.class.Obj, {}))
-  txes.push(createClass(core.class.Doc, { extends: core.class.Obj }))
-  txes.push(createClass(core.class.Class, { extends: core.class.Doc }))
-  txes.push(createClass(core.class.Space, { extends: core.class.Doc }))
-  txes.push(createClass(core.class.Account, { extends: core.class.Doc }))
+  txes.push(createClass(core.class.Obj, { kind: ClassifierKind.CLASS }))
+  txes.push(createClass(core.class.Doc, { extends: core.class.Obj, kind: ClassifierKind.CLASS }))
+  txes.push(createClass(core.class.Class, { extends: core.class.Doc, kind: ClassifierKind.CLASS, domain: DOMAIN_MODEL }))
+  txes.push(createClass(core.class.Space, { extends: core.class.Doc, kind: ClassifierKind.CLASS, domain: DOMAIN_MODEL }))
+  txes.push(createClass(core.class.Account, { extends: core.class.Doc, kind: ClassifierKind.CLASS, domain: DOMAIN_MODEL }))
 
-  txes.push(createClass(core.class.Tx, { extends: core.class.Doc }, DOMAIN_TX))
-  txes.push(createClass(core.class.TxCreateDoc, { extends: core.class.Tx }, DOMAIN_TX))
-  txes.push(createClass(core.class.TxUpdateDoc, { extends: core.class.Tx }, DOMAIN_TX))
-  txes.push(createClass(core.class.TxRemoveDoc, { extends: core.class.Tx }, DOMAIN_TX))
+  txes.push(createClass(core.class.Tx, { extends: core.class.Doc, kind: ClassifierKind.CLASS, domain: DOMAIN_TX }))
+  txes.push(createClass(core.class.TxCreateDoc, { extends: core.class.Tx, kind: ClassifierKind.CLASS }))
+  txes.push(createClass(core.class.TxUpdateDoc, { extends: core.class.Tx, kind: ClassifierKind.CLASS }))
+  txes.push(createClass(core.class.TxRemoveDoc, { extends: core.class.Tx, kind: ClassifierKind.CLASS }))
 
   txes.push(
     createDoc(core.class.Space, {