diff --git a/common/scripts/version.txt b/common/scripts/version.txt
index 293d8d75c6..74327e84bd 100644
--- a/common/scripts/version.txt
+++ b/common/scripts/version.txt
@@ -1 +1 @@
-"0.7.145"
+"0.7.145"
\ No newline at end of file
diff --git a/models/activity/src/notification.ts b/models/activity/src/notification.ts
index 521d85b8a6..c7c05922ce 100644
--- a/models/activity/src/notification.ts
+++ b/models/activity/src/notification.ts
@@ -1,8 +1,9 @@
 import notification from '@hcengineering/notification'
-import core from '@hcengineering/core'
+import core, { type ClassCollaborators } from '@hcengineering/core'
 import { type Builder } from '@hcengineering/model'
 
 import activity from './plugin'
+import { type ActivityMessage, type DocUpdateMessage } from '@hcengineering/activity'
 
 export function buildNotifications (builder: Builder): void {
   builder.createDoc(
@@ -41,11 +42,13 @@ export function buildNotifications (builder: Builder): void {
     enabledTypes: [activity.ids.AddReactionNotification]
   })
 
-  builder.mixin(activity.class.ActivityMessage, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<ActivityMessage>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: activity.class.ActivityMessage,
     fields: ['createdBy', 'repliedPersons']
   })
 
-  builder.mixin(activity.class.DocUpdateMessage, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<DocUpdateMessage>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: activity.class.DocUpdateMessage,
     fields: ['createdBy', 'repliedPersons']
   })
 
diff --git a/models/calendar/src/index.ts b/models/calendar/src/index.ts
index 904209223f..8b473541f2 100644
--- a/models/calendar/src/index.ts
+++ b/models/calendar/src/index.ts
@@ -35,7 +35,8 @@ import {
   type Markup,
   type Ref,
   type Timestamp,
-  type PersonId
+  type PersonId,
+  type ClassCollaborators
 } from '@hcengineering/core'
 import {
   ArrOf,
@@ -247,7 +248,8 @@ export function createModel (builder: Builder): void {
     calendar.ids.CalendarNotificationGroup
   )
 
-  builder.mixin(calendar.class.Event, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Event>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: calendar.class.Event,
     fields: ['participants']
   })
 
diff --git a/models/chunter/src/notifications.ts b/models/chunter/src/notifications.ts
index bc9b8c696b..2578ce45d4 100644
--- a/models/chunter/src/notifications.ts
+++ b/models/chunter/src/notifications.ts
@@ -19,13 +19,17 @@ import core from '@hcengineering/model-core'
 import activity from '@hcengineering/activity'
 
 import chunter from './plugin'
+import { type ClassCollaborators } from '@hcengineering/core'
+import { type Channel, type DirectMessage } from '@hcengineering/chunter'
 
 export function defineNotifications (builder: Builder): void {
-  builder.mixin(chunter.class.DirectMessage, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<DirectMessage>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: chunter.class.DirectMessage,
     fields: ['members']
   })
 
-  builder.mixin(chunter.class.Channel, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Channel>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: chunter.class.Channel,
     fields: ['members']
   })
 
diff --git a/models/contact/src/index.ts b/models/contact/src/index.ts
index db1cd0cc2b..4abee5afa4 100644
--- a/models/contact/src/index.ts
+++ b/models/contact/src/index.ts
@@ -36,6 +36,7 @@ import {
 } from '@hcengineering/contact'
 import {
   AccountRole,
+  type ClassCollaborators,
   DOMAIN_MODEL,
   DateRangeMode,
   IndexKind,
@@ -615,7 +616,8 @@ export function createModel (builder: Builder): void {
     inlineEditor: contact.component.ContactArrayEditor
   })
 
-  builder.mixin(contact.class.Contact, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Contact>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: contact.class.Contact,
     fields: []
   })
 
@@ -623,7 +625,8 @@ export function createModel (builder: Builder): void {
     component: contact.component.ChannelPanel
   })
 
-  builder.mixin(contact.class.Channel, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Channel>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: contact.class.Channel,
     fields: ['modifiedBy']
   })
 
diff --git a/models/controlled-documents/src/index.ts b/models/controlled-documents/src/index.ts
index 93bf5e9b40..5eb65a7784 100644
--- a/models/controlled-documents/src/index.ts
+++ b/models/controlled-documents/src/index.ts
@@ -16,6 +16,7 @@
 import activity from '@hcengineering/activity'
 import contact from '@hcengineering/contact'
 import documentsPlugin, {
+  type ControlledDocument,
   documentsId,
   DocumentState,
   type Document,
@@ -37,7 +38,7 @@ import setting from '@hcengineering/setting'
 import tags from '@hcengineering/tags'
 import textEditor from '@hcengineering/text-editor'
 
-import { AccountRole, type Class, type Doc, type Ref } from '@hcengineering/core'
+import { AccountRole, type ClassCollaborators, type Class, type Doc, type Ref } from '@hcengineering/core'
 import { type Action } from '@hcengineering/view'
 import { definePermissions } from './permissions'
 import documents from './plugin'
@@ -976,7 +977,8 @@ export function defineNotifications (builder: Builder): void {
     components: { input: { component: chunter.component.ChatMessageInput } }
   })
 
-  builder.mixin(documents.class.ControlledDocument, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<ControlledDocument>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: documents.class.ControlledDocument,
     fields: ['author', 'owner', 'reviewers', 'approvers', 'coAuthors']
   })
 
diff --git a/models/core/src/core.ts b/models/core/src/core.ts
index 5e83792388..ad9798ee40 100644
--- a/models/core/src/core.ts
+++ b/models/core/src/core.ts
@@ -14,24 +14,28 @@
 //
 
 import {
-  type PersonId,
+  type AccountUuid,
   type AnyAttribute,
   type ArrOf,
   type Association,
   type AttachedDoc,
   type Blob,
   type Class,
+  type ClassCollaborators,
   type ClassifierKind,
+  type Collaborator,
   type Collection,
   type Configuration,
   type ConfigurationElement,
   type Doc,
   type Domain,
   DOMAIN_BLOB,
+  DOMAIN_COLLABORATOR,
   DOMAIN_CONFIGURATION,
   DOMAIN_MIGRATION,
   DOMAIN_MODEL,
   DOMAIN_RELATION,
+  DOMAIN_SEQUENCE,
   type DomainIndexConfiguration,
   type Enum,
   type EnumOf,
@@ -43,18 +47,18 @@ import {
   type MigrationState,
   type Mixin,
   type Obj,
+  type PersonId,
   type PluginConfiguration,
   type Ref,
   type RefTo,
   type Relation,
-  type Space,
   type Sequence,
+  type Space,
   type Timestamp,
   type TransientConfiguration,
   type Type,
   type TypeAny,
-  type Version,
-  DOMAIN_SEQUENCE
+  type Version
 } from '@hcengineering/core'
 import {
   Hidden,
@@ -66,10 +70,10 @@ import {
   TypeBoolean,
   TypeFileSize,
   TypeIntlString,
+  TypePersonId,
   TypeRef,
   TypeString,
   TypeTimestamp,
-  TypePersonId,
   UX
 } from '@hcengineering/model'
 import { getEmbeddedLabel, type IntlString, type Plugin } from '@hcengineering/platform'
@@ -390,3 +394,15 @@ export class TSequence extends TDoc implements Sequence {
 
   sequence!: number
 }
+
+@Model(core.class.ClassCollaborators, core.class.Doc, DOMAIN_MODEL)
+export class TClassCollaborators extends TDoc implements ClassCollaborators<Doc> {
+  attachedTo!: Ref<Class<Doc>>
+  fields!: (keyof Doc)[]
+  provideSecurity?: boolean
+}
+
+@Model(core.class.Collaborator, core.class.Doc, DOMAIN_COLLABORATOR)
+export class TCollaborator extends TAttachedDoc implements Collaborator {
+  collaborator!: AccountUuid
+}
diff --git a/models/core/src/index.ts b/models/core/src/index.ts
index d30190a37a..a138a1bf6d 100644
--- a/models/core/src/index.ts
+++ b/models/core/src/index.ts
@@ -69,7 +69,9 @@ import {
   TTypeString,
   TTypeTimestamp,
   TVersion,
-  TSequence
+  TSequence,
+  TClassCollaborators,
+  TCollaborator
 } from './core'
 import { definePermissions } from './permissions'
 import { TPermission, TRole, TSpace, TSpaceType, TSpaceTypeDescriptor, TSystemSpace, TTypedSpace } from './security'
@@ -161,7 +163,9 @@ export function createModel (builder: Builder): void {
     TAssociation,
     TDomainIndexConfiguration,
     TBenchmarkDoc,
-    TTransientConfiguration
+    TTransientConfiguration,
+    TClassCollaborators,
+    TCollaborator
   )
 
   builder.createDoc(core.class.DomainIndexConfiguration, core.space.Model, {
diff --git a/models/document/src/index.ts b/models/document/src/index.ts
index ecd8bc5da4..94eb41ae01 100644
--- a/models/document/src/index.ts
+++ b/models/document/src/index.ts
@@ -14,7 +14,16 @@
 //
 
 import activity from '@hcengineering/activity'
-import type { CollectionSize, MarkupBlobRef, Domain, Rank, Ref, Role, RolesAssignment } from '@hcengineering/core'
+import type {
+  CollectionSize,
+  MarkupBlobRef,
+  Domain,
+  Rank,
+  Ref,
+  Role,
+  RolesAssignment,
+  ClassCollaborators
+} from '@hcengineering/core'
 import { AccountUuid, AccountRole, IndexKind } from '@hcengineering/core'
 import {
   type Document,
@@ -423,7 +432,8 @@ function defineDocument (builder: Builder): void {
 
   builder.mixin(document.class.Document, core.class.Class, activity.mixin.ActivityDoc, {})
 
-  builder.mixin(document.class.Document, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Document>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: document.class.Document,
     fields: ['createdBy', 'modifiedBy']
   })
 
diff --git a/models/lead/src/index.ts b/models/lead/src/index.ts
index 56964a75bf..0db4cce2b1 100644
--- a/models/lead/src/index.ts
+++ b/models/lead/src/index.ts
@@ -15,7 +15,7 @@
 
 // To help typescript locate view plugin properly
 import activity from '@hcengineering/activity'
-import { AccountRole, SortingOrder, type FindOptions } from '@hcengineering/core'
+import { AccountRole, type ClassCollaborators, SortingOrder, type FindOptions } from '@hcengineering/core'
 import { leadId, type Lead } from '@hcengineering/lead'
 import { type Builder } from '@hcengineering/model'
 import chunter from '@hcengineering/model-chunter'
@@ -539,7 +539,8 @@ export function createModel (builder: Builder): void {
     filters: ['attachedTo']
   })
 
-  builder.mixin(lead.class.Lead, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Lead>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: lead.class.Lead,
     fields: ['createdBy', 'assignee']
   })
 
diff --git a/models/love/src/index.ts b/models/love/src/index.ts
index 4dc7bb34a4..2326f2a4a7 100644
--- a/models/love/src/index.ts
+++ b/models/love/src/index.ts
@@ -24,7 +24,9 @@ import {
   type Timestamp,
   DOMAIN_TRANSIENT,
   DateRangeMode,
-  IndexKind
+  IndexKind,
+  type ClassCollaborators,
+  type AccountUuid
 } from '@hcengineering/core'
 import {
   type DevicesPreference,
@@ -157,6 +159,8 @@ export class TParticipantInfo extends TDoc implements ParticipantInfo {
   y!: number
 
   sessionId!: string | null
+
+  account!: AccountUuid | null
 }
 
 @Model(love.class.JoinRequest, core.class.Doc, DOMAIN_TRANSIENT)
@@ -663,8 +667,10 @@ export function createModel (builder: Builder): void {
     enabledTypes: [love.ids.MeetingMinutesChatNotification]
   })
 
-  builder.mixin(love.class.MeetingMinutes, core.class.Class, notification.mixin.ClassCollaborators, {
-    fields: ['createdBy']
+  builder.createDoc<ClassCollaborators<MeetingMinutes>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: love.class.MeetingMinutes,
+    fields: ['createdBy'],
+    provideSecurity: true
   })
 
   builder.mixin(love.class.Room, core.class.Class, core.mixin.IndexConfiguration, {
diff --git a/models/notification/src/index.ts b/models/notification/src/index.ts
index 69caac5bbf..26fa7ca3f4 100644
--- a/models/notification/src/index.ts
+++ b/models/notification/src/index.ts
@@ -18,9 +18,12 @@ import activity, { type ActivityMessage } from '@hcengineering/activity'
 import { type PersonSpace } from '@hcengineering/contact'
 import {
   AccountRole,
+  type Collaborator,
+  type CollectionSize,
   DOMAIN_MODEL,
+  DOMAIN_TRANSIENT,
   IndexKind,
-  type PersonId,
+  type AccountUuid,
   type AttachedDoc,
   type Class,
   type Collection,
@@ -29,41 +32,40 @@ import {
   type DocumentQuery,
   type IndexingConfiguration,
   type Markup,
+  type PersonId,
   type Ref,
   type Space,
   type Timestamp,
   type Tx,
-  type TxCUD,
-  DOMAIN_TRANSIENT,
-  type AccountUuid
+  type TxCUD
 } from '@hcengineering/core'
 import {
-  ArrOf,
+  Collection as CollectionType,
   Index,
   Mixin,
   Model,
   Prop,
+  TypeAccountUuid,
   TypeBoolean,
   TypeDate,
   TypeIntlString,
   TypeMarkup,
   TypeRef,
   UX,
-  type Builder,
-  TypeAccountUuid
+  type Builder
 } from '@hcengineering/model'
 import core, { TClass, TDoc } from '@hcengineering/model-core'
 import preference, { TPreference } from '@hcengineering/model-preference'
 import view, { createAction, template } from '@hcengineering/model-view'
 import workbench from '@hcengineering/model-workbench'
 import {
-  notificationId,
-  DOMAIN_USER_NOTIFY,
-  DOMAIN_NOTIFICATION,
+  type Collaborators,
   DOMAIN_DOC_NOTIFY,
+  DOMAIN_NOTIFICATION,
+  DOMAIN_USER_NOTIFY,
+  notificationId,
   type ActivityInboxNotification,
   type ActivityNotificationViewlet,
-  type NotificationType,
   type BrowserNotification,
   type CommonInboxNotification,
   type DocNotifyContext,
@@ -78,6 +80,7 @@ import {
   type NotificationProviderDefaults,
   type NotificationProviderSetting,
   type NotificationTemplate,
+  type NotificationType,
   type NotificationTypeSetting,
   type PushSubscription,
   type PushSubscriptionKeys
@@ -88,7 +91,7 @@ import { type AnyComponent, type Location } from '@hcengineering/ui/src/types'
 
 import notification from './plugin'
 
-export { notificationId, DOMAIN_USER_NOTIFY, DOMAIN_NOTIFICATION, DOMAIN_DOC_NOTIFY } from '@hcengineering/notification'
+export { DOMAIN_DOC_NOTIFY, DOMAIN_NOTIFICATION, DOMAIN_USER_NOTIFY, notificationId } from '@hcengineering/notification'
 export { notificationOperation } from './migration'
 export { notification as default }
 
@@ -155,17 +158,11 @@ export class TNotificationProviderSetting extends TPreference implements Notific
   enabled!: boolean
 }
 
-@Mixin(notification.mixin.ClassCollaborators, core.class.Class)
-export class TClassCollaborators extends TClass {
-  fields!: string[]
-}
-
 @Mixin(notification.mixin.Collaborators, core.class.Doc)
 @UX(notification.string.Collaborators)
-export class TCollaborators extends TDoc {
-  @Prop(ArrOf(TypeAccountUuid()), notification.string.Collaborators)
-  @Index(IndexKind.Indexed)
-    collaborators!: AccountUuid[]
+export class TCollaborators extends TDoc implements Collaborators {
+  @Prop(CollectionType(core.class.Collaborator), notification.string.Collaborators)
+    collaborators!: CollectionSize<Collaborator>
 }
 
 @Mixin(notification.mixin.NotificationObjectPresenter, core.class.Class)
@@ -342,12 +339,11 @@ export const notificationActionTemplates = template({
 
 export function createModel (builder: Builder): void {
   builder.createModel(
+    TCollaborators,
     TBrowserNotification,
     TNotificationType,
     TNotificationGroup,
     TNotificationPreferencesGroup,
-    TClassCollaborators,
-    TCollaborators,
     TNotificationObjectPresenter,
     TNotificationPreview,
     TDocNotifyContext,
@@ -434,34 +430,39 @@ export function createModel (builder: Builder): void {
       label: notification.string.Collaborators,
       group: notification.ids.NotificationGroup,
       txClasses: [],
-      objectClass: notification.mixin.Collaborators,
+      objectClass: core.class.Collaborator,
       defaultEnabled: true
     },
     notification.ids.CollaboratoAddNotification
   )
 
-  builder.createDoc(notification.class.ActivityNotificationViewlet, core.space.Model, {
-    presenter: notification.component.NotificationCollaboratorsChanged,
-    messageMatch: {
-      _class: activity.class.DocUpdateMessage,
-      'attributeUpdates.attrClass': notification.mixin.Collaborators
-    }
-  })
+  builder.createDoc(
+    activity.class.DocUpdateMessageViewlet,
+    core.space.Model,
+    {
+      objectClass: core.class.Collaborator,
+      action: 'create',
+      icon: notification.icon.Notifications,
+      component: notification.component.CollaboratorsChanged
+    },
+    notification.ids.CollaboratorsAddMessage
+  )
 
   builder.createDoc(
     activity.class.DocUpdateMessageViewlet,
     core.space.Model,
     {
-      objectClass: notification.mixin.Collaborators,
-      action: 'update',
+      objectClass: core.class.Collaborator,
+      action: 'remove',
       icon: notification.icon.Notifications,
-      label: notification.string.ChangeCollaborators
+      component: notification.component.CollaboratorsChanged
     },
-    notification.ids.CollaboratorsChangedMessage
+    notification.ids.CollaboratorsRemoveMessage
   )
 
-  builder.mixin(notification.mixin.Collaborators, core.class.Class, activity.mixin.ActivityAttributeUpdatesPresenter, {
-    presenter: notification.component.CollaboratorsChanged
+  builder.mixin(core.class.Collaborator, core.class.Class, view.mixin.CollectionEditor, {
+    editor: notification.component.CollaboratorEditor,
+    inlineEditor: notification.component.CollaboratorEditor
   })
 
   createAction(
diff --git a/models/notification/src/migration.ts b/models/notification/src/migration.ts
index 3c7bc95fd3..17e1f3d947 100644
--- a/models/notification/src/migration.ts
+++ b/models/notification/src/migration.ts
@@ -23,7 +23,10 @@ import core, {
   type DocumentQuery,
   type Ref,
   type Space,
-  type AccountUuid
+  type AccountUuid,
+  DOMAIN_COLLABORATOR,
+  type Collaborator,
+  generateId
 } from '@hcengineering/core'
 import {
   migrateSpace,
@@ -39,7 +42,8 @@ import notification, {
   type PushSubscription,
   type BrowserNotification,
   type DocNotifyContext,
-  type InboxNotification
+  type InboxNotification,
+  type OldCollaborators
 } from '@hcengineering/notification'
 import { DOMAIN_PREFERENCE } from '@hcengineering/preference'
 
@@ -239,6 +243,78 @@ export async function migrateDuplicateContexts (client: MigrationClient): Promis
   }
 }
 
+async function migrateCollaborators (client: MigrationClient): Promise<void> {
+  const alreadyMigrated = await client.find<Collaborator>(DOMAIN_COLLABORATOR, {}, { limit: 1 })
+  if (alreadyMigrated.length > 0) {
+    client.logger.log('collaborators already migrated, skipping', {})
+    return
+  }
+  const hierarchy = client.hierarchy
+  client.logger.log('processing extract collaborators ', {})
+  for (const domain of client.hierarchy.domains()) {
+    if (['tx'].includes(domain)) continue
+    client.logger.log('processing domain ', { domain })
+    let processed = 0
+    const iterator = await client.traverse(domain, {})
+
+    try {
+      while (true) {
+        const docs = await iterator.next(200)
+        if (docs === null || docs.length === 0) {
+          break
+        }
+
+        const operations: { filter: MigrationDocumentQuery<Doc>, update: MigrateUpdate<Doc> }[] = []
+
+        const collabs: Collaborator[] = []
+
+        for (const doc of docs) {
+          const mixin = hierarchy.as(doc, notification.mixin.Collaborators) as any as OldCollaborators
+          const oldCollaborators = mixin.collaborators
+
+          if (oldCollaborators === undefined || oldCollaborators.length === 0) continue
+
+          for (const collab of oldCollaborators) {
+            collabs.push({
+              _id: generateId(),
+              _class: core.class.Collaborator,
+              space: doc.space,
+              collaborator: collab,
+              attachedTo: doc._id,
+              attachedToClass: doc._class,
+              collection: 'collaborators',
+              modifiedOn: Date.now(),
+              modifiedBy: core.account.System
+            })
+          }
+
+          operations.push({
+            filter: { _id: doc._id },
+            update: {
+              $unset: {
+                'notification:mixin:Collaborators': true
+              }
+            }
+          })
+        }
+
+        if (operations.length > 0) {
+          await client.bulk(domain, operations)
+          await client.create(DOMAIN_COLLABORATOR, collabs)
+        }
+
+        processed += docs.length
+        client.logger.log('...processed', { count: processed })
+      }
+
+      client.logger.log('finished processing domain ', { domain, processed })
+    } finally {
+      await iterator.close()
+    }
+  }
+  client.logger.log('finished processing collaborators ', {})
+}
+
 /**
  * Migrates old accounts to new accounts/social ids.
  * Should be applied to prodcution directly without applying migrateSocialIdsToAccountUuids
@@ -268,8 +344,10 @@ async function migrateAccounts (client: MigrationClient): Promise<void> {
 
         const operations: { filter: MigrationDocumentQuery<Doc>, update: MigrateUpdate<Doc> }[] = []
 
+        const collabs: Collaborator[] = []
+
         for (const doc of docs) {
-          const mixin = hierarchy.as(doc, notification.mixin.Collaborators)
+          const mixin = hierarchy.as(doc, notification.mixin.Collaborators) as any as OldCollaborators
           const oldCollaborators = mixin.collaborators
 
           if (oldCollaborators === undefined || oldCollaborators.length === 0) continue
@@ -281,11 +359,25 @@ async function migrateAccounts (client: MigrationClient): Promise<void> {
             accountUuidByOldAccount
           )
 
+          for (const collab of newCollaborators) {
+            collabs.push({
+              _id: generateId(),
+              _class: core.class.Collaborator,
+              space: doc.space,
+              collaborator: collab,
+              attachedTo: doc._id,
+              attachedToClass: doc._class,
+              collection: 'collaborators',
+              modifiedOn: Date.now(),
+              modifiedBy: core.account.System
+            })
+          }
+
           operations.push({
             filter: { _id: doc._id },
             update: {
-              [`${notification.mixin.Collaborators}`]: {
-                collaborators: newCollaborators
+              $unset: {
+                'notification:mixin:Collaborators': true
               }
             }
           })
@@ -293,6 +385,7 @@ async function migrateAccounts (client: MigrationClient): Promise<void> {
 
         if (operations.length > 0) {
           await client.bulk(domain, operations)
+          await client.create(DOMAIN_COLLABORATOR, collabs)
         }
 
         processed += docs.length
@@ -751,6 +844,11 @@ export const notificationOperation: MigrateOperation = {
         state: 'accounts-to-social-ids-v2',
         mode: 'upgrade',
         func: migrateAccounts
+      },
+      {
+        state: 'migrate-collaborators',
+        mode: 'upgrade',
+        func: migrateCollaborators
       }
     ])
   },
diff --git a/models/notification/src/plugin.ts b/models/notification/src/plugin.ts
index 5d0a661d19..1647f62ab0 100644
--- a/models/notification/src/plugin.ts
+++ b/models/notification/src/plugin.ts
@@ -27,7 +27,6 @@ export default mergeIds(notificationId, notification, {
     PlatformNotification: '' as IntlString,
     BrowserNotification: '' as IntlString,
     EmailNotification: '' as IntlString,
-    Collaborators: '' as IntlString,
     Archive: '' as IntlString,
     MarkAsUnread: '' as IntlString,
     MarkAsRead: '' as IntlString,
@@ -42,7 +41,8 @@ export default mergeIds(notificationId, notification, {
     Inbox: '' as Ref<Application>
   },
   ids: {
-    CollaboratorsChangedMessage: '' as Ref<DocUpdateMessageViewlet>
+    CollaboratorsAddMessage: '' as Ref<DocUpdateMessageViewlet>,
+    CollaboratorsRemoveMessage: '' as Ref<DocUpdateMessageViewlet>
   },
   component: {
     NotificationSettings: '' as AnyComponent,
diff --git a/models/recruit/src/index.ts b/models/recruit/src/index.ts
index ac1c12ada7..d13695cffd 100644
--- a/models/recruit/src/index.ts
+++ b/models/recruit/src/index.ts
@@ -14,7 +14,7 @@
 //
 
 import activity from '@hcengineering/activity'
-import { AccountRole, SortingOrder, type Lookup, type Ref } from '@hcengineering/core'
+import { AccountRole, type ClassCollaborators, SortingOrder, type Lookup, type Ref } from '@hcengineering/core'
 import { type Builder } from '@hcengineering/model'
 import calendar from '@hcengineering/model-calendar'
 import chunter from '@hcengineering/model-chunter'
@@ -30,7 +30,7 @@ import view, { createAction, showColorsViewOption, actionTemplates as viewTempla
 import workbench, { createNavigateAction, type Application } from '@hcengineering/model-workbench'
 import notification from '@hcengineering/notification'
 import { type IntlString } from '@hcengineering/platform'
-import { recruitId, type Applicant, RecruitEvents } from '@hcengineering/recruit'
+import { recruitId, type Applicant, RecruitEvents, type Vacancy } from '@hcengineering/recruit'
 import setting from '@hcengineering/setting'
 import { type KeyBinding, type ViewOptionModel, type ViewOptionsModel } from '@hcengineering/view'
 
@@ -84,7 +84,8 @@ export function createModel (builder: Builder): void {
     editor: recruit.component.VacancyList
   })
 
-  builder.mixin(recruit.class.Vacancy, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Vacancy>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: recruit.class.Vacancy,
     fields: ['createdBy']
   })
 
@@ -96,7 +97,8 @@ export function createModel (builder: Builder): void {
     inlineEditor: view.component.ArrayEditor
   })
 
-  builder.mixin(recruit.class.Applicant, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Applicant>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: recruit.class.Applicant,
     fields: ['createdBy', 'assignee']
   })
 
diff --git a/models/request/src/index.ts b/models/request/src/index.ts
index ddaa1a8e1d..ed3526079a 100644
--- a/models/request/src/index.ts
+++ b/models/request/src/index.ts
@@ -16,7 +16,7 @@
 import activity from '@hcengineering/activity'
 import type { Person } from '@hcengineering/contact'
 import contact from '@hcengineering/contact'
-import { type Timestamp, type Domain, type Ref, type Tx } from '@hcengineering/core'
+import { type Timestamp, type Domain, type Ref, type Tx, type ClassCollaborators } from '@hcengineering/core'
 import {
   ArrOf,
   type Builder,
@@ -108,7 +108,8 @@ export function createModel (builder: Builder): void {
     presenter: request.component.RequestView
   })
 
-  builder.mixin(request.class.Request, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Request>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: request.class.Request,
     fields: ['requested', 'createdBy']
   })
 
diff --git a/models/setting/src/index.ts b/models/setting/src/index.ts
index dc6dbb7fef..bc8e5b8537 100644
--- a/models/setting/src/index.ts
+++ b/models/setting/src/index.ts
@@ -15,7 +15,15 @@
 
 import activity from '@hcengineering/activity'
 import contact from '@hcengineering/contact'
-import { AccountRole, DOMAIN_MODEL, type Blob, type Domain, type Ref, type AccountUuid } from '@hcengineering/core'
+import {
+  AccountRole,
+  DOMAIN_MODEL,
+  type Blob,
+  type Domain,
+  type Ref,
+  type AccountUuid,
+  type ClassCollaborators
+} from '@hcengineering/core'
 import { Mixin, Model, type Builder, UX } from '@hcengineering/model'
 import core, { TClass, TConfiguration, TDoc } from '@hcengineering/model-core'
 import view, { createAction } from '@hcengineering/model-view'
@@ -146,7 +154,8 @@ export function createModel (builder: Builder): void {
     setting.ids.SettingsWidget
   )
 
-  builder.mixin(setting.class.Integration, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Integration>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: setting.class.Integration,
     fields: ['modifiedBy']
   })
 
diff --git a/models/time/src/index.ts b/models/time/src/index.ts
index 3cf22ac236..83032d37a3 100644
--- a/models/time/src/index.ts
+++ b/models/time/src/index.ts
@@ -28,7 +28,8 @@ import {
   type Type,
   DateRangeMode,
   IndexKind,
-  AccountRole
+  AccountRole,
+  type ClassCollaborators
 } from '@hcengineering/core'
 import lead from '@hcengineering/lead'
 import {
@@ -386,7 +387,8 @@ export function createModel (builder: Builder): void {
     enabledTypes: [time.ids.ToDoCreated]
   })
 
-  builder.mixin(time.class.ToDo, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<ToDo>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: time.class.ToDo,
     fields: ['user']
   })
 
diff --git a/models/tracker/src/index.ts b/models/tracker/src/index.ts
index e8f1d4f6ab..0563ea0a1f 100644
--- a/models/tracker/src/index.ts
+++ b/models/tracker/src/index.ts
@@ -15,7 +15,7 @@
 
 import activity from '@hcengineering/activity'
 import chunter from '@hcengineering/chunter'
-import { AccountRole, type Ref, type Status } from '@hcengineering/core'
+import { AccountRole, type ClassCollaborators, type Ref, type Status } from '@hcengineering/core'
 import { type Builder } from '@hcengineering/model'
 import core from '@hcengineering/model-core'
 import { generateClassNotificationTypes } from '@hcengineering/model-notification'
@@ -25,7 +25,7 @@ import view from '@hcengineering/model-view'
 import workbench from '@hcengineering/model-workbench'
 import notification from '@hcengineering/notification'
 import setting from '@hcengineering/setting'
-import pluginState, { trackerId } from '@hcengineering/tracker'
+import pluginState, { type Issue, trackerId } from '@hcengineering/tracker'
 
 import type { TaskStatusFactory } from '@hcengineering/task'
 import { PaletteColorIndexes } from '@hcengineering/ui/src/colors'
@@ -502,7 +502,8 @@ export function createModel (builder: Builder): void {
 
   defineSortAndGrouping(builder)
 
-  builder.mixin(tracker.class.Issue, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<Issue>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: tracker.class.Issue,
     fields: ['createdBy', 'assignee']
   })
 
diff --git a/models/training/src/index.ts b/models/training/src/index.ts
index dcd9c2e091..cb539af8e0 100644
--- a/models/training/src/index.ts
+++ b/models/training/src/index.ts
@@ -31,7 +31,14 @@ import {
   TrainingSpecialIds
 } from '@hcengineering/training'
 
-import { AccountRole, type Data, type FindOptions, type Permission, type Ref } from '@hcengineering/core'
+import {
+  AccountRole,
+  ClassCollaborators,
+  type Data,
+  type FindOptions,
+  type Permission,
+  type Ref
+} from '@hcengineering/core'
 import { Prop, type Builder } from '@hcengineering/model'
 
 import contacts from '@hcengineering/model-contact'
@@ -569,8 +576,9 @@ function defineTrainingRequest (builder: Builder): void {
     titleProvider: training.function.TrainingRequestObjectTitleProvider
   })
 
-  builder.mixin(training.class.TrainingRequest, core.class.Class, notification.mixin.ClassCollaborators, {
-    fields: ['trainees'] as Array<keyof TrainingRequest>
+  builder.createDoc<ClassCollaborators<TrainingRequest>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: training.class.TrainingRequest,
+    fields: ['trainees']
   })
 
   builder.createDoc<NotificationType>(
diff --git a/packages/core/src/classes.ts b/packages/core/src/classes.ts
index 6fca816f2d..a069bf9dbf 100644
--- a/packages/core/src/classes.ts
+++ b/packages/core/src/classes.ts
@@ -411,6 +411,11 @@ export const DOMAIN_TRANSIENT = 'transient' as Domain
  */
 export const DOMAIN_RELATION = 'relation' as Domain
 
+/**
+ * @public
+ */
+export const DOMAIN_COLLABORATOR = 'collaborator' as Domain
+
 /**
  * @public
  */
@@ -870,3 +875,13 @@ export interface AccountInfo {
 }
 
 export type SocialKey = Pick<SocialId, 'type' | 'value'>
+
+export interface ClassCollaborators<T extends Doc> extends Doc {
+  attachedTo: Ref<Class<T>>
+  fields: (keyof T)[] // PersonId | Ref<Employee> | PersonId[] | Ref<Employee>[]
+  provideSecurity?: boolean // If true, will provide security for collaborators
+}
+
+export interface Collaborator extends AttachedDoc {
+  collaborator: AccountUuid
+}
diff --git a/packages/core/src/component.ts b/packages/core/src/component.ts
index 28a6361df3..3cf9fa75ca 100644
--- a/packages/core/src/component.ts
+++ b/packages/core/src/component.ts
@@ -60,7 +60,9 @@ import type {
   TypedSpace,
   UserStatus,
   Version,
-  AccountUuid
+  AccountUuid,
+  ClassCollaborators,
+  Collaborator
 } from './classes'
 import { type Status, type StatusCategory } from './status'
 import type {
@@ -148,6 +150,7 @@ export default plugin(coreId, {
     Version: '' as Ref<Class<Version>>,
     PluginConfiguration: '' as Ref<Class<PluginConfiguration>>,
     UserStatus: '' as Ref<Class<UserStatus>>,
+
     TypeRelatedDocument: '' as Ref<Class<Type<RelatedDocument>>>,
     DomainIndexConfiguration: '' as Ref<Class<DomainIndexConfiguration>>,
 
@@ -161,7 +164,9 @@ export default plugin(coreId, {
     FullTextSearchContext: '' as Ref<Mixin<FullTextSearchContext>>,
     Association: '' as Ref<Class<Association>>,
     Relation: '' as Ref<Class<Relation>>,
-    Sequence: '' as Ref<Class<Sequence>>
+    Sequence: '' as Ref<Class<Sequence>>,
+    ClassCollaborators: '' as Ref<Class<ClassCollaborators<Doc>>>,
+    Collaborator: '' as Ref<Class<Collaborator>>
   },
   icon: {
     TypeString: '' as Asset,
diff --git a/plugins/chunter-resources/src/components/threads/Threads.svelte b/plugins/chunter-resources/src/components/threads/Threads.svelte
index 31417db26a..a6004fc31a 100644
--- a/plugins/chunter-resources/src/components/threads/Threads.svelte
+++ b/plugins/chunter-resources/src/components/threads/Threads.svelte
@@ -13,21 +13,22 @@
 // limitations under the License.
 -->
 <script lang="ts">
-  import { getCurrentAccount, SortingOrder } from '@hcengineering/core'
-  import { createQuery } from '@hcengineering/presentation'
-  import { Scroller, Loading, Lazy } from '@hcengineering/ui'
   import activity, { ActivityMessage } from '@hcengineering/activity'
   import { ActivityMessagePresenter } from '@hcengineering/activity-resources'
-  import notification from '@hcengineering/notification'
   import attachment from '@hcengineering/attachment'
+  import core, { Collaborator, getCurrentAccount, Ref, SortingOrder } from '@hcengineering/core'
+  import { createQuery, getClient } from '@hcengineering/presentation'
+  import { Lazy, Loading, Scroller } from '@hcengineering/ui'
 
-  import chunter from '../../plugin'
-  import Header from '../Header.svelte'
   import { openMessageFromSpecial } from '../../navigation'
+  import chunter from '../../plugin'
   import BlankView from '../BlankView.svelte'
+  import Header from '../Header.svelte'
   import LoadingHistory from '../LoadingHistory.svelte'
 
   const threadsQuery = createQuery()
+  const client = getClient()
+  const h = client.getHierarchy()
 
   let threads: ActivityMessage[] = []
   let isLoading = true
@@ -37,11 +38,25 @@
   let limit = 100
   let hasNextPage = true
 
+  let collabs: Collaborator[] = []
+
+  const query = createQuery()
+  query.query(
+    core.class.Collaborator,
+    {
+      collaborator: getCurrentAccount().uuid,
+      attachedToClass: { $in: h.getDescendants(activity.class.ActivityMessage) }
+    },
+    (res) => {
+      collabs = res
+    }
+  )
+
   $: threadsQuery.query(
     activity.class.ActivityMessage,
     {
       replies: { $gte: 1 },
-      [`${notification.mixin.Collaborators}.collaborators`]: getCurrentAccount().uuid
+      _id: { $in: collabs.map((c) => c.attachedTo as Ref<ActivityMessage>) }
     },
     (res) => {
       if (res.length <= limit) {
diff --git a/plugins/gmail-resources/src/components/Main.svelte b/plugins/gmail-resources/src/components/Main.svelte
index 29f13a960c..4c47accfe9 100644
--- a/plugins/gmail-resources/src/components/Main.svelte
+++ b/plugins/gmail-resources/src/components/Main.svelte
@@ -52,7 +52,7 @@
   let integrations: Integration[] = []
   let selectedIntegration: Integration | undefined = undefined
 
-  channel && inboxClient.forceReadDoc(channel._id, channel._class)
+  channel && inboxClient.forceReadDoc(channel)
 
   const dispatch = createEventDispatcher()
 
diff --git a/plugins/gmail-resources/src/components/NewMessage.svelte b/plugins/gmail-resources/src/components/NewMessage.svelte
index df9837e05d..09423b120a 100644
--- a/plugins/gmail-resources/src/components/NewMessage.svelte
+++ b/plugins/gmail-resources/src/components/NewMessage.svelte
@@ -83,7 +83,7 @@
       objectId
     )
     Analytics.handleEvent(GmailEvents.SentEmail, { to: channel.value })
-    await inboxClient.forceReadDoc(channel._id, channel._class)
+    await inboxClient.forceReadDoc(channel)
     objectId = generateId()
     dispatch('close')
   }
diff --git a/plugins/gmail-resources/src/components/NewMessages.svelte b/plugins/gmail-resources/src/components/NewMessages.svelte
index a39cad31e1..71ae508311 100644
--- a/plugins/gmail-resources/src/components/NewMessages.svelte
+++ b/plugins/gmail-resources/src/components/NewMessages.svelte
@@ -99,7 +99,7 @@
           .filter((m) => m.length)
       })
       Analytics.handleEvent(GmailEvents.SentEmail, { to: channel.value })
-      await inboxClient.forceReadDoc(channel._id, channel._class)
+      await inboxClient.forceReadDoc(channel)
       for (const attachment of attachments) {
         await client.addCollection(
           attachmentP.class.Attachment,
diff --git a/plugins/love-resources/src/utils.ts b/plugins/love-resources/src/utils.ts
index 521fc7208c..944cba6542 100644
--- a/plugins/love-resources/src/utils.ts
+++ b/plugins/love-resources/src/utils.ts
@@ -1,7 +1,7 @@
 import aiBot from '@hcengineering/ai-bot'
 import { connectMeeting, disconnectMeeting } from '@hcengineering/ai-bot-resources'
 import { Analytics } from '@hcengineering/analytics'
-import calendar, { type Event, type Schedule, getAllEvents } from '@hcengineering/calendar'
+import calendar, { type Event, getAllEvents, type Schedule } from '@hcengineering/calendar'
 import chunter from '@hcengineering/chunter'
 import contact, { getCurrentEmployee, getName, type Person } from '@hcengineering/contact'
 import core, {
@@ -11,7 +11,6 @@ import core, {
   type Data,
   type Doc,
   type DocumentQuery,
-  generateId,
   getCurrentAccount,
   type Hierarchy,
   type Ref,
@@ -79,30 +78,30 @@ import {
   type LocalTrack,
   type LocalTrackPublication,
   LocalVideoTrack,
+  type Participant,
   type RemoteParticipant,
   type RemoteTrack,
   type RemoteTrackPublication,
   RoomEvent,
+  type ScreenShareCaptureOptions,
   Track,
-  type VideoCaptureOptions,
-  type Participant,
-  type ScreenShareCaptureOptions
+  type VideoCaptureOptions
 } from 'livekit-client'
 import { get, writable } from 'svelte/store'
 
+import { getPersonByPersonRef } from '@hcengineering/contact-resources'
 import { sendMessage } from './broadcast'
+import MeetingMinutesSearchItem from './components/MeetingMinutesSearchItem.svelte'
 import RoomSettingsPopup from './components/RoomSettingsPopup.svelte'
 import love from './plugin'
 import {
   $myPreferences,
   currentMeetingMinutes,
-  currentSession,
   currentRoom,
+  currentSession,
   myOffice,
   selectedRoomPlace
 } from './stores'
-import MeetingMinutesSearchItem from './components/MeetingMinutesSearchItem.svelte'
-import { getPersonByPersonRef } from '@hcengineering/contact-resources'
 
 export async function getToken (
   roomName: string,
@@ -753,6 +752,7 @@ async function moveToRoom (
       room: room._id,
       person: currentPerson._id,
       name: currentPerson.name,
+      account: getCurrentAccount().uuid,
       sessionId
     })
   }
@@ -787,43 +787,7 @@ async function initMeetingMinutes (room: Room): Promise<void> {
     status: MeetingStatus.Active
   })
 
-  if (doc === undefined) {
-    const date = new Date()
-      .toLocaleDateString('en-GB', {
-        day: 'numeric',
-        month: 'long',
-        year: 'numeric'
-      })
-      .replace(',', ' at')
-    const _id = generateId<MeetingMinutes>()
-    const newDoc: MeetingMinutes = {
-      _id,
-      _class: love.class.MeetingMinutes,
-      attachedTo: room._id,
-      attachedToClass: room._class,
-      collection: 'meetings',
-      space: core.space.Workspace,
-      title: `${await getRoomName(room)} ${date}`,
-      description: null,
-      status: MeetingStatus.Active,
-      modifiedBy: getCurrentAccount().primarySocialId,
-      modifiedOn: Date.now()
-    }
-    await client.addCollection(
-      love.class.MeetingMinutes,
-      core.space.Workspace,
-      room._id,
-      room._class,
-      'meetings',
-      { title: newDoc.title, description: newDoc.description, status: newDoc.status },
-      _id
-    )
-    currentMeetingMinutes.set(newDoc)
-    const loc = getCurrentLocation()
-    if (loc.path[2] === loveId || room.type === RoomType.Video) {
-      await navigateToOfficeDoc(client.getHierarchy(), newDoc)
-    }
-  } else {
+  if (doc !== undefined) {
     currentMeetingMinutes.set(doc)
     const loc = getCurrentLocation()
     if (loc.path[2] === loveId || room.type === RoomType.Video) {
@@ -952,7 +916,7 @@ export async function tryConnect (
     await client.update(invite, { status: invite.room === room._id ? RequestStatus.Approved : RequestStatus.Rejected })
   }
 
-  const isGuest = client.getHierarchy().as(currentPerson, contact.mixin.Employee).role === AccountRole.Guest
+  const isGuest = getCurrentAccount().role === AccountRole.Guest
   if ((room.access === RoomAccess.Knock || isGuest) && (!isOffice(room) || room.person !== currentPerson._id)) {
     const _id = await client.createDoc(love.class.JoinRequest, core.space.Workspace, {
       person: currentPerson._id,
diff --git a/plugins/love/src/index.ts b/plugins/love/src/index.ts
index 3d5858a27a..82374fcb40 100644
--- a/plugins/love/src/index.ts
+++ b/plugins/love/src/index.ts
@@ -1,6 +1,6 @@
 import { Event, Schedule } from '@hcengineering/calendar'
 import { Person } from '@hcengineering/contact'
-import { AttachedDoc, Class, MarkupBlobRef, Doc, Mixin, Ref, Timestamp } from '@hcengineering/core'
+import { AttachedDoc, Class, MarkupBlobRef, Doc, Mixin, Ref, Timestamp, AccountUuid } from '@hcengineering/core'
 import { Drive } from '@hcengineering/drive'
 import { NotificationType } from '@hcengineering/notification'
 import { Asset, IntlString, Metadata, Plugin, plugin } from '@hcengineering/platform'
@@ -122,6 +122,7 @@ export interface ParticipantInfo extends Doc {
   x: number
   y: number
   sessionId: string | null
+  account: AccountUuid | null
 }
 
 export interface RoomInfo extends Doc {
diff --git a/plugins/notification-resources/src/components/CollaboratorEditor.svelte b/plugins/notification-resources/src/components/CollaboratorEditor.svelte
new file mode 100644
index 0000000000..851fb25ac6
--- /dev/null
+++ b/plugins/notification-resources/src/components/CollaboratorEditor.svelte
@@ -0,0 +1,54 @@
+<!--
+// Copyright © 2025 Hardcore Engineering Inc.
+//
+// Licensed under the Eclipse Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License. You may
+// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+-->
+<script lang="ts">
+  import { AccountArrayEditor } from '@hcengineering/contact-resources'
+  import core, { AccountUuid, Collaborator, Doc } from '@hcengineering/core'
+  import { createQuery, getClient } from '@hcengineering/presentation'
+  import notification from '../plugin'
+
+  export let object: Doc
+
+  let collaborators: Collaborator[] = []
+
+  const query = createQuery()
+  const client = getClient()
+
+  query.query(
+    core.class.Collaborator,
+    {
+      attachedTo: object._id
+    },
+    (res) => {
+      collaborators = res
+    }
+  )
+
+  $: accounts = collaborators.map((c) => c.collaborator)
+
+  async function change (res: AccountUuid[]): Promise<void> {
+    const toAdd: AccountUuid[] = res.filter((a) => !accounts.includes(a))
+    const toRemove: Collaborator[] = collaborators.filter((a) => !res.includes(a.collaborator))
+    for (const account of toAdd) {
+      await client.addCollection(core.class.Collaborator, object.space, object._id, object._class, 'collaborators', {
+        collaborator: account
+      })
+    }
+    for (const collaborator of toRemove) {
+      await client.remove(collaborator)
+    }
+  }
+</script>
+
+<AccountArrayEditor label={notification.string.Collaborators} value={accounts} onChange={change} />
diff --git a/plugins/notification-resources/src/components/activity/CollaboratorsChanged.svelte b/plugins/notification-resources/src/components/activity/CollaboratorsChanged.svelte
index a7c438a0e3..5453b751eb 100644
--- a/plugins/notification-resources/src/components/activity/CollaboratorsChanged.svelte
+++ b/plugins/notification-resources/src/components/activity/CollaboratorsChanged.svelte
@@ -17,74 +17,29 @@
   import { Icon, IconAdd, IconDelete, Label } from '@hcengineering/ui'
   import { employeeRefByAccountUuidStore, PersonRefPresenter } from '@hcengineering/contact-resources'
   import { Person } from '@hcengineering/contact'
-  import { type Ref, type AccountUuid, notEmpty } from '@hcengineering/core'
-  import activity, { DocAttributeUpdates } from '@hcengineering/activity'
+  import { type Ref, type AccountUuid, notEmpty, Doc, Collaborator } from '@hcengineering/core'
+  import activity, { DisplayDocUpdateMessage, DocAttributeUpdates } from '@hcengineering/activity'
   import notification from '@hcengineering/notification'
 
-  export let value: DocAttributeUpdates
+  export let message: DisplayDocUpdateMessage
+  export let value: Collaborator
 
-  $: removed = getPersonRefs(value.removed, $employeeRefByAccountUuidStore)
-  $: added = getPersonRefs(value.added.length > 0 ? value.added : value.set, $employeeRefByAccountUuidStore)
-
-  function getPersonRefs (
-    values: DocAttributeUpdates['removed' | 'added' | 'set'],
-    personRefByAccountUuid: Map<AccountUuid, Ref<Person>>
-  ): Ref<Person>[] {
-    const persons = new Set(
-      values
-        .map((value) => {
-          if (typeof value !== 'string') {
-            return undefined
-          }
-
-          const person = personRefByAccountUuid.get(value as AccountUuid)
-
-          if (person === undefined) {
-            return undefined
-          }
-
-          return person
-        })
-        .filter(notEmpty)
-    )
-
-    return Array.from(persons)
-  }
-
-  $: hasDifferentChanges = added.length > 0 && removed.length > 0
+  $: person = $employeeRefByAccountUuidStore.get(value.collaborator)
 </script>
 
 <span class="root">
   <Icon icon={activity.icon.Activity} size="small" />
   <span class="label">
-    {#if hasDifferentChanges}
-      <Label label={notification.string.ChangedCollaborators} />:
-    {:else if added.length > 0}
+    {#if message.action === 'create'}
       <Label label={notification.string.NewCollaborators} />:
-    {:else if removed.length > 0}
+    {:else}
       <Label label={notification.string.RemovedCollaborators} />:
     {/if}
   </span>
 
-  {#if added.length > 0}
+  {#if person !== undefined}
     <span class="row">
-      {#if hasDifferentChanges}
-        <IconAdd size={'x-small'} fill={'var(--theme-trans-color)'} />
-      {/if}
-      {#each added as add}
-        <PersonRefPresenter value={add} avatarSize="card" compact />
-      {/each}
-    </span>
-  {/if}
-  <span class="antiHSpacer"></span>
-  {#if removed.length > 0}
-    <span class="row">
-      {#if hasDifferentChanges}
-        <IconDelete size={'x-small'} fill={'var(--theme-trans-color)'} />
-      {/if}
-      {#each removed as remove}
-        <PersonRefPresenter value={remove} avatarSize="card" compact />
-      {/each}
+      <PersonRefPresenter value={person} avatarSize="card" compact />
     </span>
   {/if}
 </span>
@@ -94,6 +49,7 @@
     display: flex;
     flex-wrap: wrap;
     align-items: center;
+    color: var(--global-primary-TextColor);
     gap: 0.5rem;
   }
 
diff --git a/plugins/notification-resources/src/inboxNotificationsClient.ts b/plugins/notification-resources/src/inboxNotificationsClient.ts
index a56269202a..764223c6b7 100644
--- a/plugins/notification-resources/src/inboxNotificationsClient.ts
+++ b/plugins/notification-resources/src/inboxNotificationsClient.ts
@@ -13,13 +13,12 @@
 // limitations under the License.
 //
 import activity from '@hcengineering/activity'
-import {
-  type Account,
-  type Client,
+import core, {
   SortingOrder,
   getCurrentAccount,
   toIdMap,
-  type Class,
+  type Account,
+  type Client,
   type Doc,
   type IdMap,
   type Ref,
@@ -28,7 +27,6 @@ import {
 } from '@hcengineering/core'
 import notification, {
   type ActivityInboxNotification,
-  type Collaborators,
   type DocNotifyContext,
   type InboxNotification,
   type InboxNotificationsClient
@@ -173,46 +171,25 @@ export class InboxNotificationsClientImpl implements InboxNotificationsClient {
     await op.commit()
   }
 
-  async forceReadDoc (_id: Ref<Doc>, _class: Ref<Class<Doc>>): Promise<void> {
-    const context = this._contextByDoc.get(_id)
+  async forceReadDoc (doc: Doc): Promise<void> {
+    const context = this._contextByDoc.get(doc._id)
 
     if (context !== undefined) {
-      await this.readDoc(_id)
+      await this.readDoc(doc._id)
       return
     }
 
     const client = getClient()
-    const doc = await client.findOne(_class, { _id })
 
-    if (doc === undefined) {
-      return
-    }
+    const current = await client.findOne(core.class.Collaborator, {
+      attachedTo: doc._id,
+      collaborator: getCurrentAccount().uuid
+    })
 
-    const hierarchy = client.getHierarchy()
-    const collaboratorsMixin = hierarchy.as<Doc, Collaborators>(doc, notification.mixin.Collaborators)
-
-    if (collaboratorsMixin.collaborators === undefined) {
-      await client.createMixin<Doc, Collaborators>(
-        collaboratorsMixin._id,
-        collaboratorsMixin._class,
-        collaboratorsMixin.space,
-        notification.mixin.Collaborators,
-        {
-          collaborators: [getCurrentAccount().uuid]
-        }
-      )
-    } else if (collaboratorsMixin.collaborators.includes(getCurrentAccount().uuid)) {
-      await client.updateMixin(
-        collaboratorsMixin._id,
-        collaboratorsMixin._class,
-        collaboratorsMixin.space,
-        notification.mixin.Collaborators,
-        {
-          $push: {
-            collaborators: getCurrentAccount().primarySocialId
-          }
-        }
-      )
+    if (current === undefined) {
+      await client.addCollection(core.class.Collaborator, doc.space, doc._id, doc._class, 'collaborators', {
+        collaborator: getCurrentAccount().uuid
+      })
     }
   }
 
diff --git a/plugins/notification-resources/src/index.ts b/plugins/notification-resources/src/index.ts
index c356418d42..eb17ebfbe7 100644
--- a/plugins/notification-resources/src/index.ts
+++ b/plugins/notification-resources/src/index.ts
@@ -26,6 +26,7 @@ import CommonInboxNotificationPresenter from './components/inbox/CommonInboxNoti
 import MentionInboxNotificationPresenter from './components/inbox/MentionInboxNotificationPresenter.svelte'
 import NotificationCollaboratorsChanged from './components/NotificationCollaboratorsChanged.svelte'
 import ReactionNotificationPresenter from './components/ReactionNotificationPresenter.svelte'
+import CollaboratorEditor from './components/CollaboratorEditor.svelte'
 import GeneralPreferencesGroup from './components/settings/GeneralPreferencesGroup.svelte'
 import {
   unsubscribe,
@@ -69,7 +70,8 @@ export default async (): Promise<Resources> => ({
     MentionInboxNotificationPresenter,
     NotificationCollaboratorsChanged,
     ReactionNotificationPresenter,
-    GeneralPreferencesGroup
+    GeneralPreferencesGroup,
+    CollaboratorEditor
   },
   function: {
     // eslint-disable-next-line @typescript-eslint/unbound-method
diff --git a/plugins/notification-resources/src/utils.ts b/plugins/notification-resources/src/utils.ts
index bee80416c2..042ced64fa 100644
--- a/plugins/notification-resources/src/utils.ts
+++ b/plugins/notification-resources/src/utils.ts
@@ -30,7 +30,6 @@ import chunter, { type ThreadMessage } from '@hcengineering/chunter'
 import core, {
   type Class,
   type Doc,
-  type DocumentUpdate,
   getCurrentAccount,
   type Ref,
   SortingOrder,
@@ -39,9 +38,9 @@ import core, {
 } from '@hcengineering/core'
 import notification, {
   type ActivityInboxNotification,
-  type Collaborators,
   type DisplayInboxNotification,
   type DocNotifyContext,
+  getClassCollaborators,
   type InboxNotification,
   type MentionInboxNotification,
   notificationId,
@@ -64,8 +63,8 @@ import {
 } from '@hcengineering/ui'
 import view, { decodeObjectURI, encodeObjectURI, type LinkIdProvider } from '@hcengineering/view'
 import { getObjectLinkId, parseLinkId } from '@hcengineering/view-resources'
-import { get, writable } from 'svelte/store'
 import type { LocationData } from '@hcengineering/workbench'
+import { get, writable } from 'svelte/store'
 
 import { InboxNotificationsClientImpl } from './inboxNotificationsClient'
 import { type InboxData, type InboxNotificationsFilter } from './types'
@@ -235,36 +234,22 @@ export async function subscribeDoc (
 ): Promise<void> {
   const myAcc = getCurrentAccount()
   const hierarchy = client.getHierarchy()
-
-  if (hierarchy.classHierarchyMixin(docClass, notification.mixin.ClassCollaborators) === undefined) return
+  const classCollaborators = getClassCollaborators(client.getModel(), hierarchy, docClass)
+  if (classCollaborators === undefined) return
 
   const target = doc ?? (await client.findOne(docClass, { _id: docId }))
   if (target === undefined) return
-  if (hierarchy.hasMixin(target, notification.mixin.Collaborators)) {
-    const collab = hierarchy.as(target, notification.mixin.Collaborators)
-    let collabUpdate: DocumentUpdate<Collaborators> | undefined
-    const includesMe = collab.collaborators.includes(myAcc.uuid)
-
-    if (includesMe && op === 'remove') {
-      collabUpdate = {
-        $pull: {
-          collaborators: myAcc.uuid
-        }
-      }
-    } else if (!includesMe && op === 'add') {
-      collabUpdate = {
-        $push: {
-          collaborators: myAcc.uuid
-        }
-      }
-    }
-
-    if (collabUpdate !== undefined) {
-      await client.updateMixin(collab._id, collab._class, collab.space, notification.mixin.Collaborators, collabUpdate)
-    }
-  } else if (op === 'add') {
-    await client.createMixin(docId, docClass, target.space, notification.mixin.Collaborators, {
-      collaborators: [myAcc.uuid]
+  const current = await client.findOne(core.class.Collaborator, {
+    attachedTo: docId,
+    collaborator: myAcc.uuid
+  })
+  if (op === 'remove') {
+    if (current === undefined) return // already removed
+    await client.remove(current)
+  } else {
+    if (current !== undefined) return // already added
+    await client.addCollection(core.class.Collaborator, target.space, target._id, target._class, 'collaborators', {
+      collaborator: myAcc.uuid
     })
   }
 }
diff --git a/plugins/notification/src/index.ts b/plugins/notification/src/index.ts
index 454025be79..591ec7dd66 100644
--- a/plugins/notification/src/index.ts
+++ b/plugins/notification/src/index.ts
@@ -30,7 +30,9 @@ import {
   Tx,
   TxCUD,
   TxOperations,
-  AccountUuid
+  AccountUuid,
+  Collaborator,
+  CollectionSize
 } from '@hcengineering/core'
 import type { Asset, IntlString, Metadata, Plugin, Resource } from '@hcengineering/platform'
 import { plugin } from '@hcengineering/platform'
@@ -43,6 +45,7 @@ import { PersonSpace } from '@hcengineering/contact'
 import { Readable, Writable } from './types'
 
 export * from './types'
+export * from './utils'
 
 export const DOMAIN_NOTIFICATION = 'notification' as Domain
 export const DOMAIN_DOC_NOTIFY = 'notification-dnc' as Domain
@@ -185,13 +188,6 @@ export interface NotificationTypeSetting extends Preference {
   enabled: boolean
 }
 
-/**
- * @public
- */
-export interface ClassCollaborators extends Class<Doc> {
-  fields: string[] // PersonId | Ref<Employee> | PersonId[] | Ref<Employee>[]
-}
-
 /**
  * @public
  */
@@ -203,6 +199,13 @@ export interface NotificationObjectPresenter extends Class<Doc> {
  * @public
  */
 export interface Collaborators extends Doc {
+  collaborators: CollectionSize<Collaborator>
+}
+
+/**
+ * @public
+ */
+export interface OldCollaborators extends Doc {
   collaborators: AccountUuid[]
 }
 
@@ -307,7 +310,7 @@ export interface InboxNotificationsClient {
   inboxNotificationsByContext: Readable<Map<Ref<DocNotifyContext>, InboxNotification[]>>
 
   readDoc: (_id: Ref<Doc>) => Promise<void>
-  forceReadDoc: (_id: Ref<Doc>, _class: Ref<Class<Doc>>) => Promise<void>
+  forceReadDoc: (doc: Doc) => Promise<void>
   readNotifications: (client: TxOperations, ids: Array<Ref<InboxNotification>>) => Promise<void>
   unreadNotifications: (client: TxOperations, ids: Array<Ref<InboxNotification>>) => Promise<void>
   archiveNotifications: (client: TxOperations, ids: Array<Ref<InboxNotification>>) => Promise<void>
@@ -339,7 +342,6 @@ export type NotifyFunc = (title: string, body: string, _id?: string, onClick?: (
  */
 const notification = plugin(notificationId, {
   mixin: {
-    ClassCollaborators: '' as Ref<Mixin<ClassCollaborators>>,
     Collaborators: '' as Ref<Mixin<Collaborators>>,
     NotificationObjectPresenter: '' as Ref<Mixin<NotificationObjectPresenter>>,
     NotificationPreview: '' as Ref<Mixin<NotificationPreview>>,
@@ -386,7 +388,8 @@ const notification = plugin(notificationId, {
     DocNotifyContextPresenter: '' as AnyComponent,
     NotificationCollaboratorsChanged: '' as AnyComponent,
     ReactionNotificationPresenter: '' as AnyComponent,
-    GeneralPreferencesGroup: '' as AnyComponent
+    GeneralPreferencesGroup: '' as AnyComponent,
+    CollaboratorEditor: '' as AnyComponent
   },
   action: {
     PinDocNotifyContext: '' as Ref<Action>,
@@ -435,7 +438,8 @@ const notification = plugin(notificationId, {
     SoundNotificationsDescription: '' as IntlString,
     Sound: '' as IntlString,
     NoAccessToObject: '' as IntlString,
-    ViewIn: '' as IntlString
+    ViewIn: '' as IntlString,
+    Collaborators: '' as IntlString
   },
   function: {
     Notify: '' as Resource<NotifyFunc>,
diff --git a/plugins/notification/src/utils.ts b/plugins/notification/src/utils.ts
new file mode 100644
index 0000000000..81895f4b6e
--- /dev/null
+++ b/plugins/notification/src/utils.ts
@@ -0,0 +1,37 @@
+//
+// Copyright © 2025 Hardcore Engineering Inc.
+//
+// Licensed under the Eclipse Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License. You may
+// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import core, { Class, ClassCollaborators, Doc, Hierarchy, ModelDb, Ref } from '@hcengineering/core'
+
+export function getClassCollaborators<T extends Doc> (
+  model: ModelDb,
+  hiearachy: Hierarchy,
+  _id: Ref<Class<T>>
+): ClassCollaborators<T> | undefined {
+  const ancestors = hiearachy.getAncestors(_id)
+  const collabs = new Map(
+    model
+      .findAllSync(core.class.ClassCollaborators, {
+        attachedTo: { $in: ancestors }
+      })
+      .map((c) => [c.attachedTo, c])
+  )
+  for (const ancestor of ancestors) {
+    const res = collabs.get(ancestor)
+    if (res !== undefined) {
+      return res
+    }
+  }
+}
diff --git a/plugins/recruit-resources/src/components/EditVacancy.svelte b/plugins/recruit-resources/src/components/EditVacancy.svelte
index bcc301ee4a..ca2d51a537 100644
--- a/plugins/recruit-resources/src/components/EditVacancy.svelte
+++ b/plugins/recruit-resources/src/components/EditVacancy.svelte
@@ -15,15 +15,7 @@
 -->
 <script lang="ts">
   import { AttachmentStyleBoxCollabEditor } from '@hcengineering/attachment-resources'
-  import core, {
-    ClassifierKind,
-    type CollaborativeDoc,
-    Data,
-    Doc,
-    type MarkupBlobRef,
-    Mixin,
-    Ref
-  } from '@hcengineering/core'
+  import { Data, Doc, type MarkupBlobRef, Mixin, Ref } from '@hcengineering/core'
   import notification from '@hcengineering/notification'
   import { Panel } from '@hcengineering/panel'
   import { getResource } from '@hcengineering/platform'
@@ -33,7 +25,7 @@
   import tracker from '@hcengineering/tracker'
   import { Button, Component, EditBox, IconMixin, IconMoreH, Label } from '@hcengineering/ui'
   import view from '@hcengineering/view'
-  import { DocAttributeBar, DocNavLink, showMenu } from '@hcengineering/view-resources'
+  import { DocAttributeBar, DocNavLink, getDocMixins, showMenu } from '@hcengineering/view-resources'
   import { createEventDispatcher, onDestroy } from 'svelte'
   import recruit from '../plugin'
   import VacancyApplications from './VacancyApplications.svelte'
@@ -80,24 +72,10 @@
 
   $: updateObject(_id)
 
-  const ignoreMixins: Set<Ref<Mixin<Doc>>> = new Set<Ref<Mixin<Doc>>>()
   const hierarchy = client.getHierarchy()
   let mixins: Mixin<Doc>[] = []
 
-  function getMixins (object: Doc, showAllMixins: boolean): void {
-    if (object === undefined) return
-    const descendants = hierarchy.getDescendants(core.class.Doc).map((p) => hierarchy.getClass(p))
-
-    mixins = descendants.filter(
-      (m) =>
-        m.kind === ClassifierKind.MIXIN &&
-        !ignoreMixins.has(m._id) &&
-        (hierarchy.hasMixin(object, m._id) ||
-          (showAllMixins && hierarchy.isDerived(object._class, hierarchy.getBaseClass(m._id))))
-    )
-  }
-
-  $: getMixins(object, showAllMixins)
+  $: mixins = getDocMixins(object, showAllMixins)
 
   let descriptionBox: AttachmentStyleBoxCollabEditor
   $: descriptionKey = client.getHierarchy().getAttribute(recruit.class.Vacancy, 'fullDescription')
diff --git a/plugins/telegram-resources/src/components/Chat.svelte b/plugins/telegram-resources/src/components/Chat.svelte
index 03e9d5305d..53a80059e3 100644
--- a/plugins/telegram-resources/src/components/Chat.svelte
+++ b/plugins/telegram-resources/src/components/Chat.svelte
@@ -89,7 +89,7 @@
       (res) => {
         messages = res.reverse()
         if (channel !== undefined) {
-          inboxClient.forceReadDoc(channel._id, channel._class)
+          inboxClient.forceReadDoc(channel)
         }
       },
       {
diff --git a/plugins/tracker-resources/src/components/issues/edit/ControlPanel.svelte b/plugins/tracker-resources/src/components/issues/edit/ControlPanel.svelte
index 1bf022371f..33f131bc57 100644
--- a/plugins/tracker-resources/src/components/issues/edit/ControlPanel.svelte
+++ b/plugins/tracker-resources/src/components/issues/edit/ControlPanel.svelte
@@ -20,7 +20,13 @@
   import tags from '@hcengineering/tags'
   import type { Issue } from '@hcengineering/tracker'
   import { Component, Label } from '@hcengineering/ui'
-  import { getFiltredKeys, isCollectionAttr, ObjectBox, restrictionStore } from '@hcengineering/view-resources'
+  import {
+    getDocMixins,
+    getFiltredKeys,
+    isCollectionAttr,
+    ObjectBox,
+    restrictionStore
+  } from '@hcengineering/view-resources'
 
   import tracker from '../../../plugin'
   import ComponentEditor from '../../components/ComponentEditor.svelte'
@@ -30,6 +36,7 @@
   import PriorityEditor from '../PriorityEditor.svelte'
   import RelationEditor from '../RelationEditor.svelte'
   import StatusEditor from '../StatusEditor.svelte'
+  import notification from '@hcengineering/notification'
 
   export let issue: Issue
   export let showAllMixins: boolean = false
@@ -69,18 +76,13 @@
 
   let mixins: Mixin<Doc>[] = []
 
-  $: getMixins(issue, showAllMixins)
+  $: _mixins = getDocMixins(issue, showAllMixins)
 
-  function getMixins (object: Issue, showAllMixins: boolean): void {
-    const descendants = hierarchy.getDescendants(core.class.Doc).map((p) => hierarchy.getClass(p))
+  $: mixins = _mixins.find((p) => p._id === notification.mixin.Collaborators)
+    ? _mixins
+    : [..._mixins, hierarchy.getClass(notification.mixin.Collaborators)]
 
-    mixins = descendants.filter(
-      (m) =>
-        m.kind === ClassifierKind.MIXIN &&
-        (hierarchy.hasMixin(object, m._id) ||
-          (showAllMixins && hierarchy.isDerived(tracker.class.Issue, hierarchy.getBaseClass(m._id))))
-    )
-  }
+  const allowedCollections = ['collaborators']
 
   function getMixinKeys (mixin: Ref<Mixin<Doc>>): KeyedAttribute[] {
     const mixinClass = hierarchy.getClass(mixin)
@@ -90,7 +92,7 @@
       [],
       hierarchy.isMixin(mixinClass.extends as Ref<Class<Doc>>) ? mixinClass.extends : issue._class
     )
-    return filtredKeys.filter((key) => !isCollectionAttr(hierarchy, key))
+    return filtredKeys.filter((key) => !isCollectionAttr(hierarchy, key) || allowedCollections.includes(key.key))
   }
 
   $: updateKeys(issue._class, ignoreKeys)
diff --git a/plugins/view-resources/src/components/DocAttributeBar.svelte b/plugins/view-resources/src/components/DocAttributeBar.svelte
index d40bd17524..1ec8a50779 100644
--- a/plugins/view-resources/src/components/DocAttributeBar.svelte
+++ b/plugins/view-resources/src/components/DocAttributeBar.svelte
@@ -18,6 +18,7 @@
   import setting from '@hcengineering/setting'
 
   import ClassAttributeBar from './ClassAttributeBar.svelte'
+  import notification from '@hcengineering/notification'
 
   export let object: Doc
   export let mixins: Array<Mixin<Doc>> = []
@@ -28,6 +29,11 @@
 
   const client = getClient()
   const hierarchy = client.getHierarchy()
+
+  $: _allowedCollections = [...allowedCollections, 'collaborators']
+  $: _mixins = mixins.find((p) => p._id === notification.mixin.Collaborators)
+    ? mixins
+    : [...mixins, hierarchy.getClass(notification.mixin.Collaborators)]
 </script>
 
 <ClassAttributeBar
@@ -35,13 +41,13 @@
   {object}
   {ignoreKeys}
   to={undefined}
-  {allowedCollections}
+  allowedCollections={_allowedCollections}
   {showHeader}
   {readonly}
   isMainClass
   on:update
 />
-{#each mixins as mixin}
+{#each _mixins as mixin}
   {@const to = !hierarchy.hasMixin(mixin, setting.mixin.UserMixin) ? object._class : mixin.extends}
   {#if !hierarchy.hasMixin(mixin, setting.mixin.Editable) || hierarchy.as(mixin, setting.mixin.Editable).value}
     {#key mixin._id}
@@ -51,7 +57,7 @@
         {ignoreKeys}
         {to}
         {readonly}
-        {allowedCollections}
+        allowedCollections={_allowedCollections}
         {showHeader}
         on:update
       />
diff --git a/plugins/view-resources/src/components/EditDoc.svelte b/plugins/view-resources/src/components/EditDoc.svelte
index 18c6cd7a82..8451c7f951 100644
--- a/plugins/view-resources/src/components/EditDoc.svelte
+++ b/plugins/view-resources/src/components/EditDoc.svelte
@@ -114,7 +114,7 @@
 
   let ignoreKeys: string[] = []
   let activityOptions = { enabled: true, showInput: true }
-  let allowedCollections: string[] = []
+  let allowedCollections: string[] = ['collaborators']
   let collectionArrays: string[] = []
   let inplaceAttributes: string[] = []
   let ignoreMixins: Set<Ref<Mixin<Doc>>> = new Set<Ref<Mixin<Doc>>>()
@@ -218,7 +218,7 @@
     ignoreKeys = ev.detail.ignoreKeys
     activityOptions = ev.detail.activityOptions ?? activityOptions
     ignoreMixins = new Set(ev.detail.ignoreMixins)
-    allowedCollections = ev.detail.allowedCollections ?? []
+    allowedCollections = [...(ev.detail.allowedCollections ?? []), 'collaborators']
     collectionArrays = ev.detail.collectionArrays ?? []
     title = ev.detail.title
     mixins = getDocMixins(object, showAllMixins, ignoreMixins, realObjectClass)
diff --git a/server-plugins/activity-resources/src/index.ts b/server-plugins/activity-resources/src/index.ts
index cb7d656fb9..249581af54 100644
--- a/server-plugins/activity-resources/src/index.ts
+++ b/server-plugins/activity-resources/src/index.ts
@@ -379,7 +379,7 @@ async function ActivityMessagesHandler (_txes: TxCUD<Doc>[], control: TriggerCon
     const messages = txes.map((messageTx) => TxProcessor.createDoc2Doc(messageTx as TxCreateDoc<DocUpdateMessage>))
 
     const notificationTxes = await control.ctx.with('createCollaboratorNotifications', {}, (ctx) =>
-      createCollaboratorNotifications(ctx, tx, control, messages, undefined, cache.docs as Map<Ref<Doc>, Doc>)
+      createCollaboratorNotifications(ctx, tx, control, messages)
     )
 
     result.push(...txes, ...notificationTxes)
diff --git a/server-plugins/activity-resources/src/references.ts b/server-plugins/activity-resources/src/references.ts
index 143d7fa4b1..627fca396a 100644
--- a/server-plugins/activity-resources/src/references.ts
+++ b/server-plugins/activity-resources/src/references.ts
@@ -16,39 +16,42 @@
 import activity, { type ActivityMessage, type ActivityReference, type UserMentionInfo } from '@hcengineering/activity'
 import contact, { type Employee, type Person } from '@hcengineering/contact'
 import core, {
-  type PersonId,
+  type AccountUuid,
   type Blob,
   type Class,
   type Data,
   type Doc,
   type Hierarchy,
   type Markup,
+  type MeasureContext,
+  type ModelDb,
+  type PersonId,
   type Ref,
   type Space,
   type Tx,
   type TxCreateDoc,
   type TxCUD,
   TxFactory,
-  type TxMixin,
   TxProcessor,
   type TxRemoveDoc,
   type TxUpdateDoc,
-  type Type,
-  type MeasureContext,
-  type AccountUuid
+  type Type
 } from '@hcengineering/core'
-import notification, { type MentionInboxNotification, type NotificationType } from '@hcengineering/notification'
+import notification, {
+  getClassCollaborators,
+  type MentionInboxNotification,
+  type NotificationType
+} from '@hcengineering/notification'
 import { getPerson } from '@hcengineering/server-contact'
 import { type StorageAdapter, type TriggerControl } from '@hcengineering/server-core'
 import {
+  getAllowedProviders,
   getCommonNotificationTxes,
   getNotificationProviderControl,
-  getPushCollaboratorTx,
-  getAllowedProviders,
+  getReceiversInfo,
   type NotificationProviderControl
 } from '@hcengineering/server-notification-resources'
 import { areEqualJson, extractReferences, jsonToMarkup, markupToJSON } from '@hcengineering/text-core'
-import { getReceiversInfo } from '@hcengineering/server-notification-resources'
 
 export function isDocMentioned (doc: Ref<Doc>, content: string): boolean {
   const references = []
@@ -107,7 +110,7 @@ export async function getPersonNotificationTxes (
   let collaborators: AccountUuid[] = []
 
   if ([contact.mention.Everyone, contact.mention.Here].includes(reference.attachedTo as Ref<Employee>)) {
-    collaborators = await getMultipleMentionCollaborators(reference, control, doc)
+    collaborators = await getMultipleMentionCollaborators(ctx, reference, control, doc)
   } else {
     const employee = (
       await control.findAll(ctx, contact.mixin.Employee, { _id: reference.attachedTo as Ref<Employee> })
@@ -196,16 +199,22 @@ function getUpdateMentionInfoTx (
 }
 
 async function getMultipleMentionCollaborators (
+  ctx: MeasureContext,
   reference: Data<ActivityReference>,
   control: TriggerControl,
   doc: Doc
 ): Promise<AccountUuid[]> {
-  const { hierarchy } = control
+  const { hierarchy, modelDb } = control
   const personRef = reference.attachedTo as Ref<Person>
 
-  const mixin = hierarchy.classHierarchyMixin(doc._class, notification.mixin.ClassCollaborators)
-  if (mixin === undefined) return []
-  const collaborators = hierarchy.as(doc, notification.mixin.Collaborators).collaborators
+  const classCollaborators = getClassCollaborators(modelDb, hierarchy, doc._class)
+
+  if (classCollaborators === undefined) return []
+  const collaborators = (
+    await control.findAll(ctx, core.class.Collaborator, {
+      attachedTo: doc._id
+    })
+  ).map((it) => it.collaborator)
 
   if (collaborators.length === 0) return []
   const statuses = Array.from(control.userStatusMap.values())
@@ -229,16 +238,18 @@ function checkSpace (account: AccountUuid, space: Space, control: TriggerControl
   return true
 }
 
-function getCollaboratorsTxes (control: TriggerControl, receiver: AccountUuid, object?: Doc): TxMixin<Doc, Doc>[] {
-  const res: TxMixin<Doc, Doc>[] = []
+function getCollaboratorsTxes (control: TriggerControl, receiver: AccountUuid, object?: Doc): Tx[] {
+  const res: Tx[] = []
 
   if (object !== undefined) {
-    // Add user to collaborators of object where user is mentioned
-    const objectTx = getPushCollaboratorTx(control, receiver, object)
+    const tx = control.txFactory.createTxCreateDoc(core.class.Collaborator, object.space, {
+      attachedTo: object._id,
+      collaborator: receiver,
+      attachedToClass: object._class,
+      collection: 'collaborators'
+    })
 
-    if (objectTx !== undefined) {
-      res.push(objectTx)
-    }
+    res.push(tx)
   }
 
   return res
@@ -553,6 +564,7 @@ async function getRemoveActivityReferenceTxes (
 }
 
 function guessReferenceObj (
+  modelDb: ModelDb,
   hierarchy: Hierarchy,
   tx: TxCUD<Doc>
 ): {
@@ -568,7 +580,7 @@ function guessReferenceObj (
       }
     }
 
-    const mixin = hierarchy.classHierarchyMixin(tx.objectClass, notification.mixin.ClassCollaborators)
+    const mixin = getClassCollaborators(modelDb, hierarchy, tx.objectClass)
     return mixin !== undefined
       ? {
           objectId: tx.objectId,
@@ -595,7 +607,7 @@ async function ActivityReferenceCreate (tx: TxCUD<Doc>, control: TriggerControl)
   const txFactory = new TxFactory(control.txFactory.account)
 
   const doc = TxProcessor.createDoc2Doc(ctx)
-  const target = guessReferenceObj(control.hierarchy, tx)
+  const target = guessReferenceObj(control.modelDb, control.hierarchy, tx)
 
   const txes: Tx[] = await getCreateReferencesTxes(
     control.ctx,
@@ -643,7 +655,7 @@ async function ActivityReferenceUpdate (tx: TxCUD<Doc>, control: TriggerControl)
 
   const txFactory = new TxFactory(control.txFactory.account)
   const doc = TxProcessor.updateDoc2Doc(rawDoc, ctx)
-  const target = guessReferenceObj(control.hierarchy, tx)
+  const target = guessReferenceObj(control.modelDb, control.hierarchy, tx)
 
   const txes: Tx[] = await getUpdateReferencesTxes(
     control.ctx,
diff --git a/server-plugins/activity-resources/src/utils.ts b/server-plugins/activity-resources/src/utils.ts
index d5fad00f49..dddce73272 100644
--- a/server-plugins/activity-resources/src/utils.ts
+++ b/server-plugins/activity-resources/src/utils.ts
@@ -2,10 +2,12 @@ import { type ActivityMessageControl, type DocAttributeUpdates, type DocUpdateAc
 import cardPlugin, { type Card, type Tag } from '@hcengineering/card'
 import { type ActivityUpdate, ActivityUpdateType } from '@hcengineering/communication-types'
 import core, {
+  type ArrOf,
   type AttachedDoc,
   type Attribute,
   type Class,
   type Collection,
+  combineAttributes,
   type Doc,
   type Hierarchy,
   type MeasureContext,
@@ -16,16 +18,11 @@ import core, {
   type TxCUD,
   type TxMixin,
   TxProcessor,
-  type TxUpdateDoc,
-  combineAttributes,
-  type ArrOf,
-  type AccountUuid
+  type TxUpdateDoc
 } from '@hcengineering/core'
-import notification from '@hcengineering/notification'
 import { translate } from '@hcengineering/platform'
 import { type ActivityControl, type DocObjectCache, getAllObjectTransactions } from '@hcengineering/server-activity'
 import { type TriggerControl } from '@hcengineering/server-core'
-import { getDocCollaborators } from '@hcengineering/server-notification-resources'
 
 function getAvailableAttributesKeys (tx: TxCUD<Doc>, hierarchy: Hierarchy): string[] {
   if (hierarchy.isDerived(tx._class, core.class.TxUpdateDoc)) {
@@ -148,41 +145,11 @@ interface AttributeDiff {
   removed: DocAttributeUpdates['removed']
 }
 
-async function getCollaboratorsDiff (
-  control: ActivityControl,
-  doc: Doc,
-  prevDoc: Doc | undefined
-): Promise<AttributeDiff> {
-  const { hierarchy } = control
-  const value = hierarchy.as(doc, notification.mixin.Collaborators).collaborators ?? []
-
-  let prevValue: AccountUuid[] = []
-
-  if (prevDoc !== undefined && hierarchy.hasMixin(prevDoc, notification.mixin.Collaborators)) {
-    prevValue = hierarchy.as(prevDoc, notification.mixin.Collaborators).collaborators ?? []
-  } else if (prevDoc !== undefined) {
-    const mixin = hierarchy.classHierarchyMixin(prevDoc._class, notification.mixin.ClassCollaborators)
-    prevValue =
-      mixin !== undefined
-        ? await getDocCollaborators((control as TriggerControl).ctx, prevDoc, mixin, control as TriggerControl)
-        : []
-  }
-
-  const added = value.filter((item) => !prevValue.includes(item)) as DocAttributeUpdates['added']
-  const removed = prevValue.filter((item) => !value.includes(item)) as DocAttributeUpdates['removed']
-
-  return {
-    added,
-    removed
-  }
-}
-
 export async function getAttributeDiff (
   control: ActivityControl,
   doc: Doc,
   prevDoc: Doc | undefined,
   attrKey: string,
-  attrClass: Ref<Class<Doc>>,
   mixin?: Ref<Mixin<Doc>>
 ): Promise<AttributeDiff> {
   const { hierarchy } = control
@@ -190,10 +157,6 @@ export async function getAttributeDiff (
   let actualDoc: Doc | undefined = doc
   let actualPrevDoc: Doc | undefined = prevDoc
 
-  if (mixin != null && hierarchy.isDerived(attrClass, notification.mixin.Collaborators)) {
-    return await getCollaboratorsDiff(control, doc, prevDoc)
-  }
-
   if (mixin != null) {
     actualDoc = hierarchy.as(doc, mixin)
     actualPrevDoc = prevDoc === undefined ? undefined : hierarchy.as(prevDoc, mixin)
@@ -293,14 +256,14 @@ export async function getTxAttributesUpdates (
       continue
     }
 
-    if (hierarchy.isDerived(attrClass, core.class.TypeMarkup) || mixin === notification.mixin.Collaborators) {
+    if (hierarchy.isDerived(attrClass, core.class.TypeMarkup)) {
       if (docDiff === undefined) {
         docDiff = await getDocDiff(control, updateObject._class, updateObject._id, tx._id, mixin, objectCache)
       }
     }
 
     if (Array.isArray(attrValue) && docDiff?.doc !== undefined) {
-      const diff = await getAttributeDiff(control, docDiff.doc, docDiff.prevDoc, key, attrClass, mixin)
+      const diff = await getAttributeDiff(control, docDiff.doc, docDiff.prevDoc, key, mixin)
       added.push(...diff.added)
       removed.push(...diff.removed)
       attrValue = []
@@ -483,7 +446,7 @@ export async function getNewActivityUpdates (
     }
 
     if (Array.isArray(attrValue)) {
-      const diff = await getAttributeDiff(control, card, undefined, key, attrClass, mixin)
+      const diff = await getAttributeDiff(control, card, undefined, key, mixin)
       added.push(...diff.added)
       removed.push(...diff.removed)
     }
diff --git a/server-plugins/chunter-resources/src/index.ts b/server-plugins/chunter-resources/src/index.ts
index fff606e21e..14478bd2de 100644
--- a/server-plugins/chunter-resources/src/index.ts
+++ b/server-plugins/chunter-resources/src/index.ts
@@ -16,16 +16,18 @@
 import activity, { ActivityMessage, ActivityReference } from '@hcengineering/activity'
 import chunter, { Channel, ChatMessage, chunterId, ChunterSpace, ThreadMessage } from '@hcengineering/chunter'
 import contact, { Employee, Person } from '@hcengineering/contact'
-import { getAccountBySocialId, getPerson } from '@hcengineering/server-contact'
 import core, {
-  PersonId,
+  AccountUuid,
   Class,
+  combineAttributes,
   concatLink,
   Doc,
   DocumentQuery,
   FindOptions,
   FindResult,
   Hierarchy,
+  notEmpty,
+  PersonId,
   Ref,
   Timestamp,
   Tx,
@@ -34,21 +36,19 @@ import core, {
   TxProcessor,
   TxUpdateDoc,
   UserStatus,
-  type MeasureContext,
-  combineAttributes,
-  AccountUuid,
-  notEmpty
+  type MeasureContext
 } from '@hcengineering/core'
-import notification, { DocNotifyContext, NotificationContent } from '@hcengineering/notification'
+import notification, { DocNotifyContext, getClassCollaborators, NotificationContent } from '@hcengineering/notification'
 import { getMetadata, IntlString, translate } from '@hcengineering/platform'
+import { getAccountBySocialId, getPerson } from '@hcengineering/server-contact'
 import serverCore, { TriggerControl } from '@hcengineering/server-core'
 import {
   createCollaboratorNotifications,
-  getDocCollaborators,
-  getMixinTx
+  getAddCollaboratTxes,
+  getDocCollaborators
 } from '@hcengineering/server-notification-resources'
-import { extractReferences, markupToText, stripTags } from '@hcengineering/text-core'
 import { jsonToHTML, markupToJSON } from '@hcengineering/text'
+import { extractReferences, markupToText, stripTags } from '@hcengineering/text-core'
 import { workbenchId } from '@hcengineering/workbench'
 
 import { NOTIFICATION_BODY_SIZE } from '@hcengineering/server-notification'
@@ -169,7 +169,7 @@ async function OnChatMessageCreated (ctx: MeasureContext, tx: TxCUD<Doc>, contro
 
   const message = TxProcessor.createDoc2Doc(actualTx)
   if (message.modifiedBy === core.account.System) return []
-  const mixin = hierarchy.classHierarchyMixin(message.attachedToClass, notification.mixin.ClassCollaborators)
+  const mixin = getClassCollaborators(control.modelDb, hierarchy, message.attachedToClass)
 
   if (mixin === undefined) {
     return []
@@ -192,34 +192,34 @@ async function OnChatMessageCreated (ctx: MeasureContext, tx: TxCUD<Doc>, contro
       ? await control.findAll(ctx, contact.mixin.Employee, { _id: { $in: mentionedPersons as Ref<Employee>[] } })
       : []
   const collaboratorsFromMessage = [...employees.map((it) => it.personUuid), account].filter(notEmpty)
+  let currentCollaborators = (
+    await control.findAll(ctx, core.class.Collaborator, {
+      attachedTo: targetDoc._id
+    })
+  ).map((it) => it.collaborator)
 
-  if (hierarchy.hasMixin(targetDoc, notification.mixin.Collaborators)) {
-    const collaboratorsMixin = hierarchy.as(targetDoc, notification.mixin.Collaborators)
-    const newCollabs = collaboratorsFromMessage.filter((it) => !collaboratorsMixin.collaborators.includes(it))
-    if (newCollabs.length > 0) {
-      res.push(
-        control.txFactory.createTxMixin(
-          targetDoc._id,
-          targetDoc._class,
-          targetDoc.space,
-          notification.mixin.Collaborators,
-          {
-            $push: { collaborators: { $each: newCollabs, $position: 0 } }
-          }
-        )
-      )
+  if (currentCollaborators.length === 0) {
+    const mixin = getClassCollaborators(control.modelDb, control.hierarchy, targetDoc._class)
+    if (mixin !== undefined) {
+      const collaborators = await getDocCollaborators(ctx, targetDoc, mixin, control)
+      currentCollaborators = collaborators
+      res.push(...getAddCollaboratTxes(tx.objectId, tx.objectClass, tx.objectSpace, control, collaborators))
     }
-  } else {
-    const collaborators = await getDocCollaborators(ctx, targetDoc, mixin, control)
-    res.push(getMixinTx(tx, control, Array.from(new Set(collaborators.concat(collaboratorsFromMessage)))))
   }
 
-  if (collaboratorsFromMessage.length > 0) {
-    control.txFactory.createTxMixin(message._id, message._class, message.space, notification.mixin.Collaborators, {
-      $push: {
-        $push: { collaborators: { $each: collaboratorsFromMessage, $position: 0 } }
-      }
+  for (const collab of collaboratorsFromMessage) {
+    if (currentCollaborators.includes(collab)) {
+      continue
+    }
+
+    const tx = control.txFactory.createTxCreateDoc(core.class.Collaborator, targetDoc.space, {
+      attachedTo: targetDoc._id,
+      attachedToClass: targetDoc._class,
+      collaborator: collab,
+      collection: 'collaborators'
     })
+
+    res.push(tx)
   }
 
   if (account != null && isChannel && !(targetDoc as Channel).members.includes(account)) {
diff --git a/server-plugins/contact-resources/src/index.ts b/server-plugins/contact-resources/src/index.ts
index 812009f25e..22b3f2cfbf 100644
--- a/server-plugins/contact-resources/src/index.ts
+++ b/server-plugins/contact-resources/src/index.ts
@@ -50,7 +50,6 @@ import core, {
   TxUpdateDoc,
   TypedSpace
 } from '@hcengineering/core'
-import notification, { Collaborators } from '@hcengineering/notification'
 import { getMetadata } from '@hcengineering/platform'
 import { makeRank } from '@hcengineering/rank'
 import { getAccountBySocialId, getCurrentPerson } from '@hcengineering/server-contact'
@@ -253,29 +252,13 @@ export async function OnChannelUpdate (txes: Tx[], control: TriggerControl): Pro
       const doc = (await control.findAll(control.ctx, uTx.objectClass, { _id: uTx.objectId }, { limit: 1 }))[0]
       const account = await getAccountBySocialId(control, tx.modifiedBy)
       if (doc !== undefined && account != null) {
-        if (control.hierarchy.hasMixin(doc, notification.mixin.Collaborators)) {
-          const collab = control.hierarchy.as(doc, notification.mixin.Collaborators) as Doc as Collaborators
-          if (collab.collaborators.includes(account)) {
-            result.push(
-              control.txFactory.createTxMixin(doc._id, doc._class, doc.space, notification.mixin.Collaborators, {
-                $push: {
-                  collaborators: account
-                }
-              })
-            )
-          }
-        } else {
-          const res = control.txFactory.createTxMixin<Doc, Collaborators>(
-            doc._id,
-            doc._class,
-            doc.space,
-            notification.mixin.Collaborators,
-            {
-              collaborators: [account]
-            }
-          )
-          result.push(res)
-        }
+        const tx = control.txFactory.createTxCreateDoc(core.class.Collaborator, doc.space, {
+          attachedTo: doc._id,
+          attachedToClass: doc._class,
+          collection: 'collaborators',
+          collaborator: account
+        })
+        result.push(tx)
       }
     }
   }
diff --git a/server-plugins/love-resources/src/index.ts b/server-plugins/love-resources/src/index.ts
index 244e21d7f7..ebb4832d9e 100644
--- a/server-plugins/love-resources/src/index.ts
+++ b/server-plugins/love-resources/src/index.ts
@@ -13,10 +13,13 @@
 // limitations under the License.
 //
 
-import contact, { Employee, Person, formatName, getName } from '@hcengineering/contact'
+import contact, { Employee, formatName, getName, Person } from '@hcengineering/contact'
 import core, {
+  type AccountUuid,
+  combineAttributes,
   concatLink,
   Doc,
+  generateId,
   Ref,
   Timestamp,
   Tx,
@@ -25,10 +28,7 @@ import core, {
   TxMixin,
   TxProcessor,
   TxUpdateDoc,
-  UserStatus,
-  combineAttributes,
-  type PersonUuid,
-  type AccountUuid
+  UserStatus
 } from '@hcengineering/core'
 import love, {
   Invite,
@@ -46,15 +46,15 @@ import love, {
 } from '@hcengineering/love'
 import notification from '@hcengineering/notification'
 import { getMetadata, translate } from '@hcengineering/platform'
-import serverCore, { TriggerControl } from '@hcengineering/server-core'
 import { getSocialStrings } from '@hcengineering/server-contact'
+import serverCore, { TriggerControl } from '@hcengineering/server-core'
 import {
   createPushNotification,
   getNotificationProviderControl,
   isAllowed
 } from '@hcengineering/server-notification-resources'
-import { workbenchId } from '@hcengineering/workbench'
 import view from '@hcengineering/view'
+import { workbenchId } from '@hcengineering/workbench'
 
 export async function OnEmployee (txes: Tx[], control: TriggerControl): Promise<Tx[]> {
   const result: Tx[] = []
@@ -102,7 +102,7 @@ export async function OnEmployee (txes: Tx[], control: TriggerControl): Promise<
   return result
 }
 
-async function createUserInfo (user: PersonUuid, control: TriggerControl): Promise<Tx[]> {
+async function createUserInfo (user: AccountUuid, control: TriggerControl): Promise<Tx[]> {
   const person = (await control.findAll(control.ctx, contact.class.Person, { personUuid: user }))[0]
   if (person === undefined) return []
 
@@ -117,6 +117,7 @@ async function createUserInfo (user: PersonUuid, control: TriggerControl): Promi
     room: room?._id ?? love.ids.Reception,
     x: 0,
     y: 0,
+    account: user,
     sessionId: null
   })
   const ptx = control.txFactory.createTxApplyIf(
@@ -180,25 +181,95 @@ export async function OnUserStatus (txes: Tx[], control: TriggerControl): Promis
 }
 
 async function roomJoinHandler (info: ParticipantInfo, control: TriggerControl): Promise<Tx[]> {
+  const res: Tx[] = []
   const roomInfos = await control.queryFind(control.ctx, love.class.RoomInfo, {})
   const roomInfo = roomInfos.find((ri) => ri.room === info.room)
   if (roomInfo !== undefined && !roomInfo.persons.includes(info.person)) {
-    return [
+    res.push(
       control.txFactory.createTxUpdateDoc(love.class.RoomInfo, core.space.Workspace, roomInfo._id, {
         $push: { persons: info.person }
       })
-    ]
+    )
   } else {
     const room = (await control.findAll(control.ctx, love.class.Room, { _id: info.room }))[0]
     if (room === undefined) return []
-    return [
+    res.push(
       control.txFactory.createTxCreateDoc(love.class.RoomInfo, core.space.Workspace, {
         persons: [info.person],
         room: info.room,
         isOffice: isOffice(room)
       })
-    ]
+    )
   }
+  if (info.account != null) {
+    const meetingMinutes = (
+      await control.findAll(control.ctx, love.class.MeetingMinutes, {
+        attachedTo: info.room,
+        status: MeetingStatus.Active
+      })
+    )[0]
+    if (meetingMinutes !== undefined) {
+      const colab = await control.findAll(control.ctx, core.class.Collaborator, {
+        attachedTo: meetingMinutes._id,
+        collaborator: info.account
+      })
+      if (colab.length === 0) {
+        res.push(
+          control.txFactory.createTxCreateDoc(core.class.Collaborator, core.space.Workspace, {
+            attachedTo: meetingMinutes._id,
+            attachedToClass: meetingMinutes._class,
+            collection: 'collaborators',
+            collaborator: info.account
+          })
+        )
+      }
+    } else {
+      const _id = generateId<MeetingMinutes>()
+      const date = new Date()
+        .toLocaleDateString('en-GB', {
+          day: 'numeric',
+          month: 'long',
+          year: 'numeric'
+        })
+        .replace(',', ' at')
+      res.push(
+        control.txFactory.createTxCreateDoc(
+          love.class.MeetingMinutes,
+          core.space.Workspace,
+          {
+            description: null,
+            attachedTo: info.room,
+            status: MeetingStatus.Active,
+            title: `${await getRoomName(control, info.room)} ${date}`,
+            attachedToClass: love.class.Room,
+            collection: 'meetings'
+          },
+          _id
+        )
+      )
+      res.push(
+        control.txFactory.createTxCreateDoc(core.class.Collaborator, core.space.Workspace, {
+          attachedTo: _id,
+          attachedToClass: love.class.MeetingMinutes,
+          collection: 'collaborators',
+          collaborator: info.account
+        })
+      )
+    }
+  }
+  return res
+}
+
+async function getRoomName (control: TriggerControl, roomId: Ref<Room>): Promise<string> {
+  const room = (await control.findAll(control.ctx, love.class.Room, { _id: roomId }))[0]
+  if (room === undefined) return ''
+  if (isOffice(room) && room.person !== null && room.name === '') {
+    const employee = (await control.findAll(control.ctx, contact.class.Person, { _id: room.person }))[0]
+    if (employee != null) {
+      return getName(control.hierarchy, employee)
+    }
+  }
+  return room.name
 }
 
 async function rejectJoinRequests (info: ParticipantInfo, control: TriggerControl): Promise<Tx[]> {
diff --git a/server-plugins/notification-resources/src/index.ts b/server-plugins/notification-resources/src/index.ts
index 21d4ff494b..4115ae70eb 100644
--- a/server-plugins/notification-resources/src/index.ts
+++ b/server-plugins/notification-resources/src/index.ts
@@ -15,6 +15,7 @@
 //
 
 import activity, { ActivityMessage, DocUpdateMessage } from '@hcengineering/activity'
+import { Analytics } from '@hcengineering/analytics'
 import chunter, { ChatMessage } from '@hcengineering/chunter'
 import contact, { Employee, type Person } from '@hcengineering/contact'
 import core, {
@@ -23,6 +24,8 @@ import core, {
   ArrOf,
   AttachedDoc,
   Class,
+  ClassCollaborators,
+  Collaborator,
   Collection,
   combineAttributes,
   Data,
@@ -47,21 +50,20 @@ import core, {
 } from '@hcengineering/core'
 import notification, {
   ActivityInboxNotification,
-  ClassCollaborators,
-  Collaborators,
   CommonInboxNotification,
   DocNotifyContext,
+  getClassCollaborators,
   InboxNotification,
   MentionInboxNotification,
   NotificationType
 } from '@hcengineering/notification'
 import { getResource, translate } from '@hcengineering/platform'
+import { getAccountBySocialId, getEmployeesBySocialIds } from '@hcengineering/server-contact'
 import { type TriggerControl } from '@hcengineering/server-core'
 import { NOTIFICATION_BODY_SIZE, ReceiverInfo, SenderInfo } from '@hcengineering/server-notification'
 import { markupToText, stripTags } from '@hcengineering/text-core'
-import { Analytics } from '@hcengineering/analytics'
-import { getAccountBySocialId, getEmployeesBySocialIds } from '@hcengineering/server-contact'
 
+import { PushNotificationsHandler } from './push'
 import {
   AvailableProvidersCache,
   AvailableProvidersCacheKey,
@@ -72,8 +74,6 @@ import {
   NotifyResult
 } from './types'
 import {
-  createPullCollaboratorsTx,
-  createPushCollaboratorsTx,
   getHTMLPresenter,
   getNotificationContent,
   getNotificationLink,
@@ -82,7 +82,6 @@ import {
   getReceiversInfo,
   getSenderInfo,
   getTextPresenter,
-  isAllowed,
   isMixinTx,
   isShouldNotifyTx,
   isUserEmployeeInFieldValueTypeMatch,
@@ -92,25 +91,6 @@ import {
   replaceAll,
   updateNotifyContextsSpace
 } from './utils'
-import { PushNotificationsHandler } from './push'
-
-export function getPushCollaboratorTx (
-  control: TriggerControl,
-  account: AccountUuid,
-  doc: Doc
-): TxMixin<Doc, Doc> | undefined {
-  const mixin = control.hierarchy.as(doc, notification.mixin.Collaborators)
-
-  if (mixin.collaborators === undefined || !mixin.collaborators.includes(account)) {
-    return control.txFactory.createTxMixin(doc._id, doc._class, doc.space, notification.mixin.Collaborators, {
-      $push: {
-        collaborators: account
-      }
-    })
-  }
-
-  return undefined
-}
 
 export async function getCommonNotificationTxes (
   ctx: MeasureContext,
@@ -322,7 +302,7 @@ async function getKeyCollaborators (
 export async function getDocCollaborators (
   ctx: MeasureContext,
   doc: Doc,
-  mixin: ClassCollaborators,
+  mixin: ClassCollaborators<Doc>,
   control: TriggerControl
 ): Promise<AccountUuid[]> {
   const collaborators = new Set<AccountUuid>()
@@ -720,7 +700,7 @@ export async function createCollabDocInfo (
   activityMessages: ActivityMessage[],
   params: NotifyParams,
   unsubscribe: AccountUuid[] = [],
-  cache = new Map<Ref<Doc>, Doc>()
+  cache: Map<Ref<Doc>, Doc> = new Map<Ref<Doc>, Doc>()
 ): Promise<Tx[]> {
   let res: Tx[] = []
 
@@ -823,26 +803,31 @@ export async function createCollabDocInfo (
 /**
  * @public
  */
-export function getMixinTx (
-  actualTx: TxCUD<Doc>,
+export function getAddCollaboratTxes (
+  objectId: Ref<Doc>,
+  objectClass: Ref<Class<Doc>>,
+  objectSpace: Ref<Space>,
   control: TriggerControl,
   collaborators: AccountUuid[]
-): TxMixin<Doc, Collaborators> {
-  return control.txFactory.createTxMixin(
-    actualTx.objectId,
-    actualTx.objectClass,
-    actualTx.objectSpace,
-    notification.mixin.Collaborators,
-    {
-      collaborators
-    }
-  )
+): TxCreateDoc<Collaborator>[] {
+  const res: TxCreateDoc<Collaborator>[] = []
+  for (const collaborator of collaborators) {
+    const tx = control.txFactory.createTxCreateDoc(core.class.Collaborator, objectSpace, {
+      attachedTo: objectId,
+      attachedToClass: objectClass,
+      collaborator,
+      collection: 'collaborators'
+    })
+    res.push(tx)
+  }
+  return res
 }
 
 async function getTxCollabs (
   ctx: MeasureContext,
   tx: TxCUD<Doc>,
   control: TriggerControl,
+  cache: Map<Ref<Doc>, Collaborator[]>,
   doc: Doc
 ): Promise<{
     added: AccountUuid[]
@@ -850,10 +835,7 @@ async function getTxCollabs (
     result: AccountUuid[]
   }> {
   const { hierarchy } = control
-  const mixin = hierarchy.classHierarchyMixin<Doc, ClassCollaborators>(
-    doc._class,
-    notification.mixin.ClassCollaborators
-  )
+  const mixin = getClassCollaborators(control.modelDb, hierarchy, doc._class)
   if (mixin === undefined) return { added: [], removed: [], result: [] }
 
   if (tx._class === core.class.TxCreateDoc) {
@@ -862,17 +844,20 @@ async function getTxCollabs (
   }
 
   if (tx._class === core.class.TxRemoveDoc) {
-    if (hierarchy.hasMixin(doc, notification.mixin.Collaborators)) {
-      return { added: [], removed: [], result: hierarchy.as(doc, notification.mixin.Collaborators).collaborators ?? [] }
-    }
-
     return { added: [], removed: [], result: [] }
   }
 
   if ([core.class.TxUpdateDoc, core.class.TxMixin].includes(tx._class)) {
-    const collabs = new Set(hierarchy.as(doc, notification.mixin.Collaborators).collaborators ?? [])
+    const collaborators =
+      cache.get(doc._id) ??
+      (await control.findAll(ctx, core.class.Collaborator, {
+        attachedTo: doc._id
+      }))
+    const collabs = collaborators.map((c) => c.collaborator)
     const ops = isMixinTx(tx) ? tx.attributes : (tx as TxUpdateDoc<Doc>).operations
-    const newCollaborators = (await getNewCollaborators(ops, mixin, doc._class, control)).filter((p) => !collabs.has(p))
+    const newCollaborators = (await getNewCollaborators(ops, mixin, doc._class, control)).filter(
+      (p) => !collabs.includes(p)
+    )
     const isSpace = control.hierarchy.isDerived(doc._class, core.class.Space)
     const removedCollabs = isSpace ? await getRemovedMembers(ops, mixin, (doc as Space)._class, control) : []
     const result = [...collabs, ...newCollaborators].filter((p) => !removedCollabs.includes(p))
@@ -889,37 +874,39 @@ async function getSpaceCollabTxes (
   doc: Doc,
   tx: TxCUD<Doc>,
   activityMessages: ActivityMessage[],
-  cache: Map<Ref<Doc>, Doc>
+  cache: Map<Ref<Doc>, Collaborator[]>,
+  docCache: Map<Ref<Doc>, Doc>
 ): Promise<Tx[]> {
   if (doc.space === core.space.Space) {
     return []
   }
 
-  const space = await getObjectSpace(control, doc, cache)
+  const space = await getObjectSpace(control, doc, docCache)
   if (space === undefined) return []
 
-  cache.set(space._id, space)
+  docCache.set(space._id, space)
 
-  const mixin = control.hierarchy.classHierarchyMixin<Doc, ClassCollaborators>(
-    space._class,
-    notification.mixin.ClassCollaborators
-  )
+  const mixin = getClassCollaborators(control.modelDb, control.hierarchy, space._class)
   if (mixin !== undefined) {
-    const collabs = control.hierarchy.as<Doc, Collaborators>(space, notification.mixin.Collaborators)
-    if (collabs.collaborators !== undefined) {
-      return await createCollabDocInfo(
-        ctx,
-        [],
-        collabs.collaborators,
-        control,
-        tx,
-        doc,
-        activityMessages,
-        { isSpace: true, isOwn: false, shouldUpdateTimestamp: true },
-        [],
-        cache
-      )
-    }
+    const collaborators =
+      cache.get(space._id) ??
+      (await control.findAll(ctx, core.class.Collaborator, {
+        attachedTo: space._id
+      }))
+    cache.set(space._id, collaborators)
+    const collabs = collaborators.map((c) => c.collaborator)
+    return await createCollabDocInfo(
+      ctx,
+      [],
+      collabs,
+      control,
+      tx,
+      doc,
+      activityMessages,
+      { isSpace: true, isOwn: false, shouldUpdateTimestamp: true },
+      [],
+      docCache
+    )
   }
   return []
 }
@@ -953,29 +940,29 @@ async function createCollaboratorDoc (
   tx: TxCreateDoc<Doc>,
   control: TriggerControl,
   activityMessage: ActivityMessage[],
-  cache: Map<Ref<Doc>, Doc>
+  cache: Map<Ref<Doc>, Collaborator[]>,
+  docCache: Map<Ref<Doc>, Doc>
 ): Promise<Tx[]> {
   const res: Tx[] = []
   const hierarchy = control.hierarchy
-  const mixin = hierarchy.classHierarchyMixin(tx.objectClass, notification.mixin.ClassCollaborators)
-
+  const mixin = getClassCollaborators(control.modelDb, hierarchy, tx.objectClass)
   if (mixin === undefined) {
     return res
   }
 
   const doc = TxProcessor.createDoc2Doc(tx)
   const collaborators = await ctx.with('get-collaborators', {}, (ctx) => getDocCollaborators(ctx, doc, mixin, control))
-  const mixinTx = getMixinTx(tx, control, collaborators)
+  const mixinTx = getAddCollaboratTxes(tx.objectId, tx.objectClass, tx.objectSpace, control, collaborators)
 
-  res.push(mixinTx)
+  res.push(...mixinTx)
 
   res.push(
     ...(await ctx.with('get-space-collabtxes', {}, (ctx) =>
-      getSpaceCollabTxes(ctx, control, doc, tx, activityMessage, cache)
+      getSpaceCollabTxes(ctx, control, doc, tx, activityMessage, cache, docCache)
     ))
   )
 
-  res.push(...(await pushCollaboratorsToPublicSpace(control, doc, collaborators, cache)))
+  res.push(...(await pushCollaboratorsToPublicSpace(control, doc, collaborators, docCache)))
 
   const notificationTxes = await ctx.with('create-collabdocinfo', {}, (ctx) =>
     createCollabDocInfo(
@@ -992,7 +979,7 @@ async function createCollaboratorDoc (
         shouldUpdateTimestamp: true
       },
       [],
-      cache
+      docCache
     )
   )
 
@@ -1001,128 +988,25 @@ async function createCollaboratorDoc (
   return res
 }
 
-async function updateCollaboratorsMixin (
-  ctx: MeasureContext,
-  tx: TxMixin<Doc, Collaborators>,
-  control: TriggerControl,
-  activityMessages: ActivityMessage[],
-  originTx: TxCUD<Doc>,
-  cache: Map<Ref<Doc>, Doc>
-): Promise<Tx[]> {
-  const { hierarchy } = control
-
-  if (tx._class !== core.class.TxMixin) return []
-  if (originTx.space === core.space.DerivedTx) return []
-  if (!hierarchy.isDerived(tx.mixin, notification.mixin.Collaborators)) return []
-
-  const res: Tx[] = []
-
-  const notificationControl = await getNotificationProviderControl(ctx, control)
-
-  if (tx.attributes.collaborators !== undefined) {
-    const createTx = (
-      await control.findAll(ctx, core.class.TxCreateDoc, {
-        objectId: tx.objectId
-      })
-    )[0]
-    const mixinTxes = await control.findAll(ctx, core.class.TxMixin, {
-      objectId: tx.objectId
-    })
-    const prevDoc = TxProcessor.buildDoc2Doc([createTx, ...mixinTxes].filter((t) => t._id !== tx._id)) as Doc
-    const newCollabs: AccountUuid[] = []
-
-    let prevCollabs: Set<AccountUuid>
-
-    if (hierarchy.hasMixin(prevDoc, notification.mixin.Collaborators)) {
-      const prevDocMixin = control.hierarchy.as(prevDoc, notification.mixin.Collaborators)
-      prevCollabs = new Set(prevDocMixin.collaborators ?? [])
-    } else {
-      const mixin = hierarchy.classHierarchyMixin(prevDoc._class, notification.mixin.ClassCollaborators)
-      prevCollabs = mixin !== undefined ? new Set(await getDocCollaborators(ctx, prevDoc, mixin, control)) : new Set()
-    }
-
-    const type = await control.modelDb.findOne(notification.class.NotificationType, {
-      _id: notification.ids.CollaboratoAddNotification
-    })
-
-    if (type === undefined) {
-      return res
-    }
-
-    const providers = await control.modelDb.findAll(notification.class.NotificationProvider, {})
-    const sender: SenderInfo = await getSenderInfo(ctx, tx.modifiedBy, control)
-    const receivers = await getReceiversInfo(ctx, tx.attributes.collaborators, control)
-
-    for (const collab of tx.attributes.collaborators) {
-      const info = receivers.find((it) => it.account === collab)
-      if (info === undefined) continue
-      if (!prevCollabs.has(collab) && sender.person?.personUuid !== collab) {
-        for (const provider of providers) {
-          if (isAllowed(control, info.socialIds, type, provider, notificationControl)) {
-            newCollabs.push(collab)
-            break
-          }
-        }
-      }
-    }
-
-    if (newCollabs.length > 0) {
-      const object = cache.get(tx.objectId) ?? (await control.findAll(ctx, tx.objectClass, { _id: tx.objectId }))[0]
-      if (object === undefined) return res
-      const space = await getObjectSpace(control, object, cache)
-
-      cache.set(object._id, object)
-      cache.set(space._id, space)
-
-      const docNotifyContexts = await control.findAll(ctx, notification.class.DocNotifyContext, {
-        user: { $in: newCollabs },
-        objectId: tx.objectId
-      })
-
-      const infos = receivers.filter((it) => newCollabs.includes(it.account))
-
-      for (const target of infos) {
-        const isMember = space.members.includes(target.account)
-        if (space.private && !isMember) continue
-
-        if (!hierarchy.isDerived(space._class, core.class.SystemSpace) && !isMember) {
-          res.push(
-            control.txFactory.createTxUpdateDoc(space._class, space.space, space._id, {
-              $push: { members: target.account }
-            })
-          )
-        }
-
-        for (const message of activityMessages) {
-          await pushActivityInboxNotifications(
-            ctx,
-            originTx,
-            control,
-            res,
-            target,
-            sender,
-            prevDoc,
-            docNotifyContexts,
-            message,
-            [],
-            true
-          )
-        }
-      }
-    }
-  }
-  return res
-}
-
 async function collectionCollabDoc (
   ctx: MeasureContext,
   tx: TxCUD<AttachedDoc>,
   control: TriggerControl,
   activityMessages: ActivityMessage[],
-  cache: Map<Ref<Doc>, Doc>,
+  cache: Map<Ref<Doc>, Collaborator[]>,
+  docCache: Map<Ref<Doc>, Doc>,
   ignoreCollection: boolean = false
 ): Promise<Tx[]> {
-  let res = await createCollaboratorNotifications(ctx, tx, control, activityMessages, tx, cache, ignoreCollection)
+  let res = await createCollaboratorNotifications(
+    ctx,
+    tx,
+    control,
+    activityMessages,
+    tx,
+    cache,
+    docCache,
+    ignoreCollection
+  )
 
   if (![core.class.TxCreateDoc, core.class.TxRemoveDoc, core.class.TxUpdateDoc].includes(tx._class)) {
     return res
@@ -1134,7 +1018,7 @@ async function collectionCollabDoc (
     return res
   }
 
-  const mixin = control.hierarchy.classHierarchyMixin(attachedToClass, notification.mixin.ClassCollaborators)
+  const mixin = getClassCollaborators(control.modelDb, control.hierarchy, attachedToClass)
 
   if (mixin === undefined) {
     return res
@@ -1144,14 +1028,14 @@ async function collectionCollabDoc (
     'get-doc',
     {},
     async (ctx) =>
-      cache.get(attachedTo) ?? (await control.findAll(ctx, attachedToClass, { _id: attachedTo }, { limit: 1 }))[0]
+      docCache.get(attachedTo) ?? (await control.findAll(ctx, attachedToClass, { _id: attachedTo }, { limit: 1 }))[0]
   )
 
   if (doc === undefined) {
     return res
   }
 
-  cache.set(doc._id, doc)
+  docCache.set(doc._id, doc)
 
   const collaborators = await ctx.with('get-collaborators', {}, (ctx) => getCollaborators(ctx, doc, control, tx, res))
 
@@ -1171,7 +1055,7 @@ async function collectionCollabDoc (
           shouldUpdateTimestamp: true
         },
         [],
-        cache
+        docCache
       )
     )
   )
@@ -1203,8 +1087,7 @@ async function removeContextNotifications (
   )
 }
 async function removeCollaboratorDoc (tx: TxRemoveDoc<Doc>, control: TriggerControl): Promise<Tx[]> {
-  const hierarchy = control.hierarchy
-  const mixin = hierarchy.classHierarchyMixin(tx.objectClass, notification.mixin.ClassCollaborators)
+  const mixin = getClassCollaborators(control.modelDb, control.hierarchy, tx.objectClass)
 
   if (mixin === undefined) {
     return []
@@ -1241,14 +1124,14 @@ async function removeCollaboratorDoc (tx: TxRemoveDoc<Doc>, control: TriggerCont
 
 async function getNewCollaborators (
   ops: DocumentUpdate<Doc> | MixinUpdate<Doc, Doc>,
-  mixin: ClassCollaborators,
+  mixin: ClassCollaborators<Doc>,
   docClass: Ref<Class<Doc>>,
   control: TriggerControl
 ): Promise<AccountUuid[]> {
   const newCollaborators = new Set<AccountUuid>()
   if (ops.$push !== undefined) {
     for (const key in ops.$push) {
-      if (mixin.fields.includes(key)) {
+      if (mixin.fields.includes(key as any)) {
         let value = (ops.$push as any)[key]
         if (typeof value !== 'string') {
           value = value.$each
@@ -1264,7 +1147,7 @@ async function getNewCollaborators (
   }
   for (const key in ops) {
     if (key.startsWith('$')) continue
-    if (mixin.fields.includes(key)) {
+    if (mixin.fields.includes(key as any)) {
       const value = (ops as any)[key]
       const newCollabs = await getKeyCollaborators(docClass, value, key, control)
       if (newCollabs !== undefined) {
@@ -1280,14 +1163,14 @@ async function getNewCollaborators (
 
 async function getRemovedMembers (
   ops: DocumentUpdate<Space> | MixinUpdate<Space, Space>,
-  mixin: ClassCollaborators,
+  mixin: ClassCollaborators<Doc>,
   docClass: Ref<Class<Space>>,
   control: TriggerControl
 ): Promise<AccountUuid[]> {
   const removedCollaborators: AccountUuid[] = []
   if (ops.$pull !== undefined && 'members' in ops.$pull) {
     const key = 'members'
-    if (mixin.fields.includes(key)) {
+    if (mixin.fields.includes(key as any)) {
       let value = (ops.$pull as any)[key]
       if (typeof value !== 'string') {
         value = value.$in
@@ -1302,68 +1185,112 @@ async function getRemovedMembers (
   return Array.from(new Set(removedCollaborators))
 }
 
+async function createSyncCollaboratorsTxes (
+  ctx: MeasureContext,
+  control: TriggerControl,
+  cache: Map<Ref<Doc>, Collaborator[]>,
+  objectId: Ref<Doc>,
+  objectClass: Ref<Class<Doc>>,
+  objectSpace: Ref<Space>,
+  added: AccountUuid[],
+  removed: AccountUuid[]
+): Promise<{ txes: Tx[], toAdd: AccountUuid[] }> {
+  const res: Tx[] = []
+  let currentCollaborators =
+    cache.get(objectId) ??
+    (await control.findAll(ctx, core.class.Collaborator, {
+      attachedTo: objectId
+    }))
+
+  const toAdd = added.filter((p) => currentCollaborators.find((c) => c.collaborator === p) === undefined)
+
+  if (toAdd.length === 0 && removed.length === 0) return { txes: res, toAdd: [] }
+
+  if (toAdd.length > 0) {
+    const txes = getAddCollaboratTxes(objectId, objectClass, objectSpace, control, toAdd)
+    res.push(...txes)
+    txes.forEach((tx) => {
+      const collab = TxProcessor.createDoc2Doc(tx)
+      currentCollaborators.push(collab)
+    })
+  }
+
+  if (removed.length > 0) {
+    const toRemove: Collaborator[] = []
+    const collabs: Collaborator[] = []
+    for (const collab of currentCollaborators) {
+      if (removed.includes(collab.collaborator)) {
+        toRemove.push(collab)
+      } else {
+        collabs.push(collab)
+      }
+    }
+    for (const removedCollab of toRemove) {
+      res.push(control.txFactory.createTxRemoveDoc(core.class.Collaborator, removedCollab.space, removedCollab._id))
+    }
+    currentCollaborators = collabs
+  }
+
+  cache.set(objectId, currentCollaborators)
+
+  return { txes: res, toAdd }
+}
+
 async function updateCollaboratorDoc (
   ctx: MeasureContext,
   tx: TxUpdateDoc<Doc> | TxMixin<Doc, Doc>,
   control: TriggerControl,
   activityMessages: ActivityMessage[],
-  cache: Map<Ref<Doc>, Doc>
+  cache: Map<Ref<Doc>, Collaborator[]>,
+  docCache: Map<Ref<Doc>, Doc>
 ): Promise<Tx[]> {
   const hierarchy = control.hierarchy
   let res: Tx[] = []
-  const mixin = hierarchy.classHierarchyMixin(tx.objectClass, notification.mixin.ClassCollaborators)
+  const mixin = getClassCollaborators(control.modelDb, hierarchy, tx.objectClass)
   if (mixin === undefined) return []
   const doc = await ctx.with(
     'find-doc',
     { _class: tx.objectClass },
     async (ctx) =>
-      cache.get(tx.objectId) ?? (await control.findAll(ctx, tx.objectClass, { _id: tx.objectId }, { limit: 1 }))[0]
+      docCache.get(tx.objectId) ?? (await control.findAll(ctx, tx.objectClass, { _id: tx.objectId }, { limit: 1 }))[0]
   )
   if (doc === undefined) return []
-  cache.set(doc._id, doc)
+  docCache.set(doc._id, doc)
   const params: NotifyParams = { isOwn: true, isSpace: false, shouldUpdateTimestamp: true }
-  if (hierarchy.hasMixin(doc, notification.mixin.Collaborators)) {
-    // we should handle change field and subscribe new collaborators
-    const collabsInfo = await ctx.with('get-tx-collaborators', {}, (ctx) => getTxCollabs(ctx, tx, control, doc))
+  // we should handle change field and subscribe new collaborators
+  const collabsInfo = await ctx.with('get-tx-collaborators', {}, (ctx) => getTxCollabs(ctx, tx, control, cache, doc))
+  const sync = await createSyncCollaboratorsTxes(
+    ctx,
+    control,
+    cache,
+    doc._id,
+    doc._class,
+    doc.space,
+    collabsInfo.added,
+    collabsInfo.removed
+  )
+  res.push(...sync.txes)
 
-    if (collabsInfo.added.length > 0) {
-      res.push(createPushCollaboratorsTx(control, tx.objectId, tx.objectClass, tx.objectSpace, collabsInfo.added))
-      // res.push(...(await pushCollaboratorsToPublicSpace(control, doc, collabsInfo.added, cache)))
-    }
-
-    if (collabsInfo.removed.length > 0) {
-      res.push(createPullCollaboratorsTx(control, tx.objectId, tx.objectClass, tx.objectSpace, collabsInfo.removed))
-    }
-
-    res = res.concat(
-      await ctx.with('create-collab-docinfo', {}, (ctx) =>
-        createCollabDocInfo(
-          ctx,
-          res,
-          collabsInfo.result,
-          control,
-          tx,
-          doc,
-          activityMessages,
-          params,
-          collabsInfo.removed,
-          cache
-        )
+  res = res.concat(
+    await ctx.with('create-collab-docinfo', {}, (ctx) =>
+      createCollabDocInfo(
+        ctx,
+        res,
+        collabsInfo.result,
+        control,
+        tx,
+        doc,
+        activityMessages,
+        params,
+        collabsInfo.removed,
+        docCache
       )
     )
-  } else {
-    const collaborators = await ctx.with('get-doc-collaborators', {}, (ctx) =>
-      getDocCollaborators(ctx, doc, mixin, control)
-    )
-    res.push(getMixinTx(tx, control, collaborators))
-    res = res.concat(
-      await createCollabDocInfo(ctx, res, collaborators, control, tx, doc, activityMessages, params, [], cache)
-    )
-  }
+  )
 
   res = res.concat(
     await ctx.with('get-space-collabtxes', {}, (ctx) =>
-      getSpaceCollabTxes(ctx, control, doc, tx, activityMessages, cache)
+      getSpaceCollabTxes(ctx, control, doc, tx, activityMessages, cache, docCache)
     )
   )
   res = res.concat(
@@ -1446,62 +1373,49 @@ async function updateCollaborators (
   ctx: MeasureContext,
   control: TriggerControl,
   tx: TxCUD<Doc>,
-  cache: Map<Ref<Doc>, Doc> = new Map<Ref<Doc>, Doc>()
+  cache: Map<Ref<Doc>, Collaborator[]>
 ): Promise<Tx[]> {
-  if (tx._class !== core.class.TxUpdateDoc && tx._class !== core.class.TxMixin) return []
+  if (tx._class !== core.class.TxCreateDoc && tx._class !== core.class.TxRemoveDoc) return []
+  if (tx.objectClass !== core.class.Collaborator) return []
 
   const hierarchy = control.hierarchy
 
-  const mixin = hierarchy.classHierarchyMixin(tx.objectClass, notification.mixin.ClassCollaborators)
-  if (mixin === undefined) return []
+  const mixin = getClassCollaborators(control.modelDb, hierarchy, tx.objectClass)
+  if (mixin === undefined || tx.attachedToClass === undefined || tx.attachedTo === undefined) return []
 
-  const { objectClass, objectId, objectSpace } = tx
-  const ops = isMixinTx(tx) ? tx.attributes : (tx as TxUpdateDoc<Doc>).operations
-  const addedCollaborators = await getNewCollaborators(ops, mixin, objectClass, control)
-  const isSpace = control.hierarchy.isDerived(objectClass, core.class.Space)
-  const removedCollaborators = isSpace
-    ? await getRemovedMembers(ops, mixin, objectClass as Ref<Class<Space>>, control)
-    : []
-
-  if (removedCollaborators.length === 0 && addedCollaborators.length === 0) return []
-
-  const doc =
-    cache.get(objectId) ?? (await control.findAll(control.ctx, objectClass, { _id: objectId }, { limit: 1 }))[0]
-  cache.set(objectId, doc)
-  if (doc === undefined) return []
+  if (hierarchy.classHierarchyMixin(tx.attachedToClass, activity.mixin.ActivityDoc) === undefined) return []
 
+  const contexts = await control.findAll(control.ctx, notification.class.DocNotifyContext, { objectId: tx.attachedTo })
   const res: Tx[] = []
-  const currentCollaborators = new Set(hierarchy.as(doc, notification.mixin.Collaborators).collaborators)
-  const toAdd = addedCollaborators.filter((p) => !currentCollaborators.has(p))
+  if (tx._class === core.class.TxCreateDoc) {
+    const collab = TxProcessor.createDoc2Doc(tx as TxCreateDoc<Collaborator>)
+    const addedInfo = await getReceiversInfo(ctx, [collab.collaborator], control)
 
-  if (toAdd.length === 0 && removedCollaborators.length === 0) return []
-
-  if (toAdd.length > 0) {
-    res.push(createPushCollaboratorsTx(control, objectId, objectClass, objectSpace, toAdd))
-    // res.push(...(await pushCollaboratorsToPublicSpace(control, doc, toAdd, cache)))
-  }
-
-  if (removedCollaborators.length > 0) {
-    res.push(createPullCollaboratorsTx(control, objectId, objectClass, objectSpace, removedCollaborators))
-  }
-
-  if (hierarchy.classHierarchyMixin(objectClass, activity.mixin.ActivityDoc) === undefined) return res
-
-  const contexts = await control.findAll(control.ctx, notification.class.DocNotifyContext, { objectId })
-  const addedInfo = await getReceiversInfo(ctx, toAdd, control)
-
-  for (const info of addedInfo.values()) {
-    const context = getDocNotifyContext(control, contexts, objectId, info.account)
-    if (context !== undefined) {
-      if (context.hidden) {
-        res.push(control.txFactory.createTxUpdateDoc(context._class, context.space, context._id, { hidden: false }))
+    for (const info of addedInfo.values()) {
+      const context = getDocNotifyContext(control, contexts, tx.attachedTo, info.account)
+      if (context !== undefined) {
+        if (context.hidden) {
+          res.push(control.txFactory.createTxUpdateDoc(context._class, context.space, context._id, { hidden: false }))
+        }
       }
+      await createNotifyContext(
+        ctx,
+        control,
+        tx.attachedTo,
+        tx.attachedToClass,
+        tx.objectSpace,
+        info,
+        tx.modifiedBy,
+        undefined,
+        tx
+      )
     }
-    await createNotifyContext(ctx, control, objectId, objectClass, objectSpace, info, tx.modifiedBy, undefined, tx)
+  } else {
+    const removed = control.removedMap.get(tx.objectId) as Collaborator
+    if (removed === undefined) return []
+    await removeContexts(ctx, contexts, [removed.collaborator], control)
   }
 
-  await removeContexts(ctx, contexts, removedCollaborators, control)
-
   return res
 }
 
@@ -1511,7 +1425,8 @@ export async function createCollaboratorNotifications (
   control: TriggerControl,
   activityMessages: ActivityMessage[],
   originTx?: TxCUD<Doc>,
-  cache: Map<Ref<Doc>, Doc> = new Map<Ref<Doc>, Doc>(),
+  cache: Map<Ref<Doc>, Collaborator[]> = new Map<Ref<Doc>, Collaborator[]>(),
+  docCache: Map<Ref<Doc>, Doc> = new Map<Ref<Doc>, Doc>(),
   ignoreCollection: boolean = false
 ): Promise<Tx[]> {
   if (tx.space === core.space.DerivedTx) {
@@ -1525,32 +1440,20 @@ export async function createCollaboratorNotifications (
 
   if (tx.attachedTo !== undefined && !ignoreCollection) {
     return await ctx.with('collectionCollabDoc', {}, (ctx) =>
-      collectionCollabDoc(ctx, tx as TxCUD<AttachedDoc>, control, activityMessages, cache, true)
+      collectionCollabDoc(ctx, tx as TxCUD<AttachedDoc>, control, activityMessages, cache, docCache, true)
     )
   }
 
   switch (tx._class) {
     case core.class.TxCreateDoc: {
       return await ctx.with('createCollaboratorDoc', {}, (ctx) =>
-        createCollaboratorDoc(ctx, tx as TxCreateDoc<Doc>, control, activityMessages, cache)
+        createCollaboratorDoc(ctx, tx as TxCreateDoc<Doc>, control, activityMessages, cache, docCache)
       )
     }
     case core.class.TxUpdateDoc:
     case core.class.TxMixin: {
-      let res = await ctx.with('updateCollaboratorDoc', {}, (ctx) =>
-        updateCollaboratorDoc(ctx, tx as TxUpdateDoc<Doc>, control, activityMessages, cache)
-      )
-      res = res.concat(
-        await ctx.with('updateCollaboratorMixin', {}, (ctx) =>
-          updateCollaboratorsMixin(
-            ctx,
-            tx as TxMixin<Doc, Collaborators>,
-            control,
-            activityMessages,
-            originTx ?? tx,
-            cache
-          )
-        )
+      const res = await ctx.with('updateCollaboratorDoc', {}, (ctx) =>
+        updateCollaboratorDoc(ctx, tx as TxUpdateDoc<Doc>, control, activityMessages, cache, docCache)
       )
       return res
     }
@@ -1583,18 +1486,22 @@ export async function getCollaborators (
   tx: TxCUD<Doc>,
   res: Tx[]
 ): Promise<AccountUuid[]> {
-  const mixin = control.hierarchy.classHierarchyMixin(doc._class, notification.mixin.ClassCollaborators)
+  const mixin = getClassCollaborators(control.modelDb, control.hierarchy, doc._class)
 
   if (mixin === undefined) {
     return []
   }
 
-  if (control.hierarchy.hasMixin(doc, notification.mixin.Collaborators)) {
-    return control.hierarchy.as(doc, notification.mixin.Collaborators).collaborators
+  const collaborators = await control.findAll(ctx, core.class.Collaborator, {
+    attachedTo: doc._id
+  })
+
+  if (collaborators.length > 0) {
+    return collaborators.map((p) => p.collaborator)
   } else {
     const collaborators = await getDocCollaborators(ctx, doc, mixin, control)
 
-    res.push(getMixinTx(tx, control, collaborators))
+    res.push(...getAddCollaboratTxes(tx.objectId, tx.objectClass, tx.objectSpace, control, collaborators))
     return collaborators
   }
 }
@@ -1712,8 +1619,8 @@ async function OnDocRemove (txes: TxCUD<Doc>[], control: TriggerControl): Promis
   return res
 }
 
-export * from './types'
 export * from './push'
+export * from './types'
 export * from './utils'
 
 // eslint-disable-next-line @typescript-eslint/explicit-function-return-type
diff --git a/server-plugins/notification-resources/src/utils.ts b/server-plugins/notification-resources/src/utils.ts
index 4fd4d01c6a..fcdbdb69e1 100644
--- a/server-plugins/notification-resources/src/utils.ts
+++ b/server-plugins/notification-resources/src/utils.ts
@@ -47,7 +47,6 @@ import core, {
   TxUpdateDoc
 } from '@hcengineering/core'
 import notification, {
-  Collaborators,
   NotificationContent,
   notificationId,
   NotificationProvider,
@@ -56,6 +55,7 @@ import notification, {
   type NotificationTypeSetting
 } from '@hcengineering/notification'
 import { getMetadata, getResource, IntlString, translate } from '@hcengineering/platform'
+import { getPersonSpaces } from '@hcengineering/server-contact'
 import serverCore, { TriggerControl } from '@hcengineering/server-core'
 import serverNotification, {
   HTMLPresenter,
@@ -65,10 +65,9 @@ import serverNotification, {
   TextPresenter
 } from '@hcengineering/server-notification'
 import serverView from '@hcengineering/server-view'
+import { extractReferences, markupToJSON, Reference } from '@hcengineering/text-core'
 import { encodeObjectURI } from '@hcengineering/view'
 import { workbenchId } from '@hcengineering/workbench'
-import { extractReferences, markupToJSON, Reference } from '@hcengineering/text-core'
-import { getPersonSpaces } from '@hcengineering/server-contact'
 
 import { NotifyResult } from './types'
 
@@ -567,35 +566,6 @@ export async function getSenderInfo (
   }
 }
 
-export function createPushCollaboratorsTx (
-  control: TriggerControl,
-  objectId: Ref<Doc>,
-  objectClass: Ref<Class<Doc>>,
-  space: Ref<Space>,
-  collaborators: AccountUuid[]
-): TxMixin<Doc, Collaborators> {
-  return control.txFactory.createTxMixin(objectId, objectClass, space, notification.mixin.Collaborators, {
-    $push: {
-      collaborators: {
-        $each: collaborators,
-        $position: 0
-      }
-    }
-  })
-}
-
-export function createPullCollaboratorsTx (
-  control: TriggerControl,
-  objectId: Ref<Doc>,
-  objectClass: Ref<Class<Doc>>,
-  space: Ref<Space>,
-  collaborators: AccountUuid[]
-): TxMixin<Doc, Collaborators> {
-  return control.txFactory.createTxMixin(objectId, objectClass, space, notification.mixin.Collaborators, {
-    $pull: { collaborators: { $in: collaborators } }
-  })
-}
-
 export async function getNotificationLink (
   control: TriggerControl,
   doc: Doc,
diff --git a/server-plugins/time-resources/src/index.ts b/server-plugins/time-resources/src/index.ts
index a7dd25ba1c..8821ba4502 100644
--- a/server-plugins/time-resources/src/index.ts
+++ b/server-plugins/time-resources/src/index.ts
@@ -241,15 +241,6 @@ export async function OnToDoCreate (txes: TxCUD<Doc>[], control: TriggerControl)
       continue
     }
 
-    const mixin = hierarchy.classHierarchyMixin(
-      createTx.objectClass as Ref<Class<Doc>>,
-      notification.mixin.ClassCollaborators
-    )
-
-    if (mixin === undefined) {
-      continue
-    }
-
     const todo = TxProcessor.createDoc2Doc(createTx)
     const object = (await control.findAll(control.ctx, todo.attachedToClass, { _id: todo.attachedTo }))[0]
     if (object === undefined) {
diff --git a/server/postgres/src/schemas.ts b/server/postgres/src/schemas.ts
index e25d708220..a96cc98473 100644
--- a/server/postgres/src/schemas.ts
+++ b/server/postgres/src/schemas.ts
@@ -1,4 +1,4 @@
-import { DOMAIN_MODEL_TX, DOMAIN_RELATION, DOMAIN_SPACE, DOMAIN_TX } from '@hcengineering/core'
+import { DOMAIN_COLLABORATOR, DOMAIN_MODEL_TX, DOMAIN_RELATION, DOMAIN_SPACE, DOMAIN_TX } from '@hcengineering/core'
 
 export type DataType = 'bigint' | 'bool' | 'text' | 'text[]'
 
@@ -70,6 +70,25 @@ const defaultSchema: Schema = {
   }
 }
 
+const collaboratorSchema: Schema = {
+  ...baseSchema,
+  attachedTo: {
+    type: 'text',
+    notNull: true,
+    index: true
+  },
+  attachedToClass: {
+    type: 'text',
+    notNull: true,
+    index: true
+  },
+  collaborator: {
+    type: 'text',
+    notNull: true,
+    index: true
+  }
+}
+
 const spaceSchema: Schema = {
   ...baseSchema,
   private: {
@@ -297,6 +316,7 @@ export const domainSchemas: Record<string, Schema> = {
   [translateDomain('github_sync')]: docSyncInfo,
   [translateDomain('github_user')]: githubLogin,
   [DOMAIN_RELATION]: relationSchema,
+  [DOMAIN_COLLABORATOR]: collaboratorSchema,
   kanban: defaultSchema
 }
 
diff --git a/server/postgres/src/storage.ts b/server/postgres/src/storage.ts
index d869c322f4..d0dc09cc0e 100644
--- a/server/postgres/src/storage.ts
+++ b/server/postgres/src/storage.ts
@@ -22,6 +22,7 @@ import core, {
   type DocumentQuery,
   type DocumentUpdate,
   type Domain,
+  DOMAIN_COLLABORATOR,
   DOMAIN_MODEL,
   DOMAIN_MODEL_TX,
   DOMAIN_RELATION,
@@ -673,7 +674,7 @@ abstract class PostgresAdapterBase implements DbAdapter {
           const select = `SELECT ${this.getProjection(vars, domain, projection, joins, options?.associations)} FROM ${domain}`
 
           const showArchived = shouldShowArchived(query, options)
-          const secJoin = this.addSecurity(vars, query, showArchived, domain, ctx.contextData)
+          const secJoin = this.addSecurity(_class, vars, query, showArchived, domain, ctx.contextData)
           if (secJoin !== undefined) {
             sqlChunks.push(secJoin)
           }
@@ -694,7 +695,7 @@ abstract class PostgresAdapterBase implements DbAdapter {
             if (options?.total === true) {
               const pvars = new ValuesVariables()
               const showArchived = shouldShowArchived(query, options)
-              const secJoin = this.addSecurity(pvars, query, showArchived, domain, ctx.contextData)
+              const secJoin = this.addSecurity(_class, pvars, query, showArchived, domain, ctx.contextData)
               const totalChunks: string[] = []
               if (secJoin !== undefined) {
                 totalChunks.push(secJoin)
@@ -784,6 +785,7 @@ abstract class PostgresAdapterBase implements DbAdapter {
   }
 
   addSecurity<T extends Doc>(
+    _class: Ref<Class<T>>,
     vars: ValuesVariables,
     query: DocumentQuery<T>,
     showArchived: boolean,
@@ -801,8 +803,15 @@ abstract class PostgresAdapterBase implements DbAdapter {
         const key = domain === DOMAIN_SPACE ? '_id' : domain === DOMAIN_TX ? '"objectSpace"' : 'space'
         const privateCheck = domain === DOMAIN_SPACE ? ' OR sec.private = false' : ''
         const archivedCheck = showArchived ? '' : ' AND sec.archived = false'
-        const q = `(sec.members @> '{"${acc.uuid}"}' OR sec."_class" = '${core.class.SystemSpace}'${privateCheck})${archivedCheck}`
-        return `INNER JOIN ${translateDomain(DOMAIN_SPACE)} AS sec ON sec._id = ${domain}.${key} AND sec."workspaceId" = ${vars.add(this.workspaceId, '::uuid')} AND ${q}`
+        const q = `(sec._id = '${core.space.Space}' OR sec."_class" = '${core.class.SystemSpace}' OR sec.members @> '{"${acc.uuid}"}'${privateCheck})${archivedCheck}`
+        const res = `INNER JOIN ${translateDomain(DOMAIN_SPACE)} AS sec ON sec._id = ${domain}.${key} AND sec."workspaceId" = ${vars.add(this.workspaceId, '::uuid')} AND ${q}`
+
+        const collabSec = this.modelDb.findAllSync(core.class.ClassCollaborators, { attachedTo: _class })[0]
+        if (collabSec === undefined || collabSec.provideSecurity !== true || acc.role !== AccountRole.Guest) {
+          return res
+        }
+        const collab = ` INNER JOIN ${translateDomain(DOMAIN_COLLABORATOR)} AS collab_sec ON collab_sec.collaborator = '${acc.uuid}' AND collab_sec."attachedTo" = ${domain}._id AND collab_sec."workspaceId" = ${vars.add(this.workspaceId, '::uuid')} AND ${q}`
+        return res + collab
       }
     }
   }
diff --git a/services/ai-bot/pod-ai-bot/src/workspace/love.ts b/services/ai-bot/pod-ai-bot/src/workspace/love.ts
index aaf7071c3d..6d40db5ba2 100644
--- a/services/ai-bot/pod-ai-bot/src/workspace/love.ts
+++ b/services/ai-bot/pod-ai-bot/src/workspace/love.ts
@@ -28,7 +28,8 @@ import core, {
   TxProcessor,
   TxUpdateDoc,
   WorkspaceUuid,
-  pickPrimarySocialId
+  pickPrimarySocialId,
+  AccountUuid
 } from '@hcengineering/core'
 import love, {
   getFreeRoomPlace,
@@ -273,6 +274,7 @@ export class LoveController {
       room: room._id,
       person: this.currentPerson._id,
       name: this.currentPerson.name,
+      account: (this.currentPerson.personUuid as AccountUuid) ?? null,
       sessionId: null
     })
   }
diff --git a/services/github/model-github/src/index.ts b/services/github/model-github/src/index.ts
index 1ad1aa1fbb..29dd341b13 100644
--- a/services/github/model-github/src/index.ts
+++ b/services/github/model-github/src/index.ts
@@ -27,30 +27,22 @@ import core, { TAttachedDoc, TDoc } from '@hcengineering/model-core'
 import github from './plugin'
 
 import {
+  AccountRole,
   DateRangeMode,
   IndexKind,
-  type PersonId,
   type Class,
+  type ClassCollaborators,
   type Data,
   type Doc,
   type Domain,
   type Hyperlink,
   type Markup,
+  type PersonId,
   type Ref,
-  type Timestamp,
-  AccountRole
+  type Timestamp
 } from '@hcengineering/core'
 
 import { type Person } from '@hcengineering/contact'
-import contact, { TPerson } from '@hcengineering/model-contact'
-import presentation from '@hcengineering/model-presentation'
-import tracker, { TComponent, TIssue, TProject, issuesOptions } from '@hcengineering/model-tracker'
-import view, { classPresenter } from '@hcengineering/model-view'
-import workbench from '@hcengineering/model-workbench'
-import { getEmbeddedLabel } from '@hcengineering/platform'
-import setting from '@hcengineering/setting'
-import tags from '@hcengineering/tags'
-import task from '@hcengineering/task'
 import {
   type DocSyncInfo,
   type GithubAuthentication,
@@ -77,6 +69,15 @@ import {
   type MinimizeReason,
   type PullRequestMergeable
 } from '@hcengineering/github'
+import contact, { TPerson } from '@hcengineering/model-contact'
+import presentation from '@hcengineering/model-presentation'
+import tracker, { TComponent, TIssue, TProject, issuesOptions } from '@hcengineering/model-tracker'
+import view, { classPresenter } from '@hcengineering/model-view'
+import workbench from '@hcengineering/model-workbench'
+import { getEmbeddedLabel } from '@hcengineering/platform'
+import setting from '@hcengineering/setting'
+import tags from '@hcengineering/tags'
+import task from '@hcengineering/task'
 
 import { generateClassNotificationTypes } from '@hcengineering/model-notification'
 
@@ -617,7 +618,8 @@ export function createModel (builder: Builder): void {
     editor: github.component.EditPullRequest
   })
 
-  builder.mixin(github.class.GithubPullRequest, core.class.Class, notification.mixin.ClassCollaborators, {
+  builder.createDoc<ClassCollaborators<GithubPullRequest>>(core.class.ClassCollaborators, core.space.Model, {
+    attachedTo: github.class.GithubPullRequest,
     fields: ['createdBy', 'assignee', 'reviewers']
   })