diff --git a/acltree/acltree_test.go b/acltree/acltree_test.go
index ebf3e4c2..8f5665ac 100644
--- a/acltree/acltree_test.go
+++ b/acltree/acltree_test.go
@@ -10,6 +10,12 @@ import (
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/testutils/threadbuilder"
 )
 
+type mockListener struct{}
+
+func (m *mockListener) Update(tree ACLTree) {}
+
+func (m *mockListener) Rebuild(tree ACLTree) {}
+
 func TestACLTree_UserJoinBuild(t *testing.T) {
 	thr, err := threadbuilder.NewThreadBuilderFromFile("threadbuilder/userjoinexample.yml")
 	if err != nil {
@@ -21,7 +27,8 @@ func TestACLTree_UserJoinBuild(t *testing.T) {
 		SignKey:  keychain.SigningKeys["A"],
 		EncKey:   keychain.EncryptionKeys["A"],
 	}
-	tree, err := BuildACLTree(thr, accountData)
+	listener := &mockListener{}
+	tree, err := BuildACLTree(thr, accountData, listener)
 	if err != nil {
 		t.Fatalf("should Build acl ACLState without err: %v", err)
 	}
@@ -55,7 +62,8 @@ func TestACLTree_UserRemoveBuild(t *testing.T) {
 		SignKey:  keychain.SigningKeys["A"],
 		EncKey:   keychain.EncryptionKeys["A"],
 	}
-	tree, err := BuildACLTree(thr, accountData)
+	listener := &mockListener{}
+	tree, err := BuildACLTree(thr, accountData, listener)
 	if err != nil {
 		t.Fatalf("should Build acl ACLState without err: %v", err)
 	}
@@ -85,7 +93,8 @@ func TestACLTree_UserRemoveBeforeBuild(t *testing.T) {
 		SignKey:  keychain.SigningKeys["A"],
 		EncKey:   keychain.EncryptionKeys["A"],
 	}
-	tree, err := BuildACLTree(thr, accountData)
+	listener := &mockListener{}
+	tree, err := BuildACLTree(thr, accountData, listener)
 	if err != nil {
 		t.Fatalf("should Build acl ACLState without err: %v", err)
 	}
@@ -116,7 +125,8 @@ func TestACLTree_InvalidSnapshotBuild(t *testing.T) {
 		SignKey:  keychain.SigningKeys["A"],
 		EncKey:   keychain.EncryptionKeys["A"],
 	}
-	tree, err := BuildACLTree(thr, accountData)
+	listener := &mockListener{}
+	tree, err := BuildACLTree(thr, accountData, listener)
 	if err != nil {
 		t.Fatalf("should Build acl ACLState without err: %v", err)
 	}
@@ -146,7 +156,8 @@ func TestACLTree_ValidSnapshotBuild(t *testing.T) {
 		SignKey:  keychain.SigningKeys["A"],
 		EncKey:   keychain.EncryptionKeys["A"],
 	}
-	tree, err := BuildACLTree(thr, accountData)
+	listener := &mockListener{}
+	tree, err := BuildACLTree(thr, accountData, listener)
 	if err != nil {
 		t.Fatalf("should Build acl ACLState without err: %v", err)
 	}
diff --git a/acltree/acltreebuilder.go b/acltree/acltreebuilder.go
index 7c552407..dfb855fe 100644
--- a/acltree/acltreebuilder.go
+++ b/acltree/acltreebuilder.go
@@ -6,7 +6,6 @@ import (
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/thread"
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/keys"
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/slice"
-	gothread "github.com/textileio/go-threads/core/thread"
 )
 
 type aclTreeBuilder struct {
@@ -56,11 +55,7 @@ func (tb *aclTreeBuilder) Build() (*Tree, error) {
 }
 
 func (tb *aclTreeBuilder) buildTreeFromStart(heads []string) (err error) {
-	changes, possibleRoots, err := tb.dfsFromStart(heads)
-	if len(possibleRoots) == 0 {
-		return fmt.Errorf("cannot have Tree without root")
-	}
-	root, err := tb.getRoot(possibleRoots)
+	changes, root, err := tb.dfsFromStart(heads)
 	if err != nil {
 		return err
 	}
@@ -70,7 +65,8 @@ func (tb *aclTreeBuilder) buildTreeFromStart(heads []string) (err error) {
 	return
 }
 
-func (tb *aclTreeBuilder) dfsFromStart(heads []string) (buf []*Change, possibleRoots []*Change, err error) {
+func (tb *aclTreeBuilder) dfsFromStart(heads []string) (buf []*Change, root *Change, err error) {
+	var possibleRoots []*Change
 	stack := make([]string, len(heads), len(heads)*2)
 	copy(stack, heads)
 
@@ -98,32 +94,14 @@ func (tb *aclTreeBuilder) dfsFromStart(heads []string) (buf []*Change, possibleR
 			possibleRoots = append(possibleRoots, ch)
 		}
 	}
-	return buf, possibleRoots, nil
-}
-
-func (tb *aclTreeBuilder) getRoot(possibleRoots []*Change) (*Change, error) {
-	threadId, err := gothread.Decode(tb.thread.ID())
-	if err != nil {
-		return nil, err
-	}
-
+	header := tb.thread.Header()
 	for _, r := range possibleRoots {
-		id := r.Content.Identity
-		sk, err := tb.signingPubKeyDecoder.DecodeFromString(id)
-		if err != nil {
-			continue
-		}
-
-		res, err := thread.VerifyACLThreadID(sk, threadId)
-		if err != nil {
-			continue
-		}
-
-		if res {
-			return r, nil
+		if r.Id == header.FirstChangeId {
+			return buf, r, nil
 		}
 	}
-	return nil, fmt.Errorf("could not find any root")
+
+	return nil, nil, fmt.Errorf("could not find root change")
 }
 
 func (tb *aclTreeBuilder) getACLHeads(heads []string) (aclTreeHeads []string, err error) {
diff --git a/acltree/treebuilder.go b/acltree/treebuilder.go
index 0e3bc79d..944a44e1 100644
--- a/acltree/treebuilder.go
+++ b/acltree/treebuilder.go
@@ -9,7 +9,6 @@ import (
 	//"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/lib/logging"
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/slice"
 	"github.com/prometheus/common/log"
-	gothread "github.com/textileio/go-threads/core/thread"
 )
 
 var (
@@ -71,11 +70,7 @@ func (tb *treeBuilder) Build(fromStart bool) (*Tree, error) {
 }
 
 func (tb *treeBuilder) buildTreeFromStart(heads []string) (err error) {
-	changes, possibleRoots, err := tb.dfsFromStart(heads)
-	if len(possibleRoots) == 0 {
-		return fmt.Errorf("cannot have Tree without root")
-	}
-	root, err := tb.getRoot(possibleRoots)
+	changes, root, err := tb.dfsFromStart(heads)
 	if err != nil {
 		return err
 	}
@@ -85,7 +80,8 @@ func (tb *treeBuilder) buildTreeFromStart(heads []string) (err error) {
 	return
 }
 
-func (tb *treeBuilder) dfsFromStart(heads []string) (buf []*Change, possibleRoots []*Change, err error) {
+func (tb *treeBuilder) dfsFromStart(heads []string) (buf []*Change, root *Change, err error) {
+	var possibleRoots []*Change
 	stack := make([]string, len(heads), len(heads)*2)
 	copy(stack, heads)
 
@@ -113,7 +109,14 @@ func (tb *treeBuilder) dfsFromStart(heads []string) (buf []*Change, possibleRoot
 			possibleRoots = append(possibleRoots, ch)
 		}
 	}
-	return buf, possibleRoots, nil
+	header := tb.thread.Header()
+	for _, r := range possibleRoots {
+		if r.Id == header.FirstChangeId {
+			return buf, r, nil
+		}
+	}
+
+	return nil, nil, fmt.Errorf("could not find root change")
 }
 
 func (tb *treeBuilder) buildTree(heads []string, breakpoint string) (err error) {
@@ -287,28 +290,3 @@ func (tb *treeBuilder) findCommonForTwoSnapshots(s1, s2 string) (s string, err e
 
 	return s2, nil
 }
-
-func (tb *treeBuilder) getRoot(possibleRoots []*Change) (*Change, error) {
-	threadId, err := gothread.Decode(tb.thread.ID())
-	if err != nil {
-		return nil, err
-	}
-
-	for _, r := range possibleRoots {
-		id := r.Content.Identity
-		sk, err := tb.signingPubKeyDecoder.DecodeFromString(id)
-		if err != nil {
-			continue
-		}
-
-		res, err := thread.VerifyACLThreadID(sk, threadId)
-		if err != nil {
-			continue
-		}
-
-		if res {
-			return r, nil
-		}
-	}
-	return nil, fmt.Errorf("could not find any root")
-}
diff --git a/testutils/threadbuilder/invalidsnapshotexample.yml b/testutils/threadbuilder/invalidsnapshotexample.yml
index e3877b47..e592f7d6 100644
--- a/testutils/threadbuilder/invalidsnapshotexample.yml
+++ b/testutils/threadbuilder/invalidsnapshotexample.yml
@@ -117,6 +117,9 @@ graph:
     baseSnapshot: A.1.2
     aclHeads: [A.1.2]
     treeHeads: [A.1.2]
+header:
+  firstChangeId: A.1.1
+  isWorkspace: false
 orphans:
   - A.1.3
   - B.1.2
diff --git a/testutils/threadbuilder/threadbuilder.go b/testutils/threadbuilder/threadbuilder.go
index 72784452..9cfd25f8 100644
--- a/testutils/threadbuilder/threadbuilder.go
+++ b/testutils/threadbuilder/threadbuilder.go
@@ -13,6 +13,7 @@ import (
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/aclchanges/pb"
 	testpb "github.com/anytypeio/go-anytype-infrastructure-experiments/testutils/testchanges/pb"
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/thread"
+	threadpb "github.com/anytypeio/go-anytype-infrastructure-experiments/thread/pb"
 	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/keys"
 )
 
@@ -34,6 +35,7 @@ type ThreadBuilder struct {
 	heads          []string
 	orphans        []string
 	keychain       *Keychain
+	header         *threadpb.ThreadHeader
 }
 
 func NewThreadBuilder(keychain *Keychain) *ThreadBuilder {
@@ -167,6 +169,10 @@ func (t *ThreadBuilder) GetUpdatedChanges() []*thread.RawChange {
 	return res
 }
 
+func (t *ThreadBuilder) Header() *threadpb.ThreadHeader {
+	return t.header
+}
+
 func (t *ThreadBuilder) getChange(changeId string, m map[string]*threadChange) *thread.RawChange {
 	rec := m[changeId]
 
@@ -510,3 +516,10 @@ func (t *ThreadBuilder) parseGraph(thread *YMLThread) {
 func (t *ThreadBuilder) parseOrphans(thread *YMLThread) {
 	t.orphans = thread.Orphans
 }
+
+func (t *ThreadBuilder) parseHeader(thread *YMLThread) {
+	t.header = &threadpb.ThreadHeader{
+		FirstChangeId: thread.Header.FirstChangeId,
+		IsWorkspace:   thread.Header.IsWorkspace,
+	}
+}
diff --git a/testutils/threadbuilder/userjoinexample.yml b/testutils/threadbuilder/userjoinexample.yml
index c2a0b11b..88f9ed92 100644
--- a/testutils/threadbuilder/userjoinexample.yml
+++ b/testutils/threadbuilder/userjoinexample.yml
@@ -99,6 +99,9 @@ graph:
     baseSnapshot: A.1.1
     aclHeads: [B.1.1]
     treeHeads: [B.1.1]
+header:
+  firstChangeId: A.1.1
+  isWorkspace: false
 orphans:
   - "A.1.3"
 updatedChanges:
diff --git a/testutils/threadbuilder/userjoinexampleupdate.yml b/testutils/threadbuilder/userjoinexampleupdate.yml
index daf5d550..8e489521 100644
--- a/testutils/threadbuilder/userjoinexampleupdate.yml
+++ b/testutils/threadbuilder/userjoinexampleupdate.yml
@@ -101,6 +101,9 @@ graph:
     baseSnapshot: A.1.1
     aclHeads: [B.1.1]
     treeHeads: [B.1.1]
+header:
+  firstChangeId: A.1.1
+  isWorkspace: false
 orphans:
   - "A.1.3"
 updatedChanges:
diff --git a/testutils/threadbuilder/userremovebeforeexample.yml b/testutils/threadbuilder/userremovebeforeexample.yml
index 7569ec04..c19ccaa6 100644
--- a/testutils/threadbuilder/userremovebeforeexample.yml
+++ b/testutils/threadbuilder/userremovebeforeexample.yml
@@ -104,3 +104,6 @@ graph:
 orphans:
   - "A.1.3"
   - "B.1.2"
+header:
+  firstChangeId: A.1.1
+  isWorkspace: false
diff --git a/testutils/threadbuilder/userremoveexample.yml b/testutils/threadbuilder/userremoveexample.yml
index 36a4a191..614a0687 100644
--- a/testutils/threadbuilder/userremoveexample.yml
+++ b/testutils/threadbuilder/userremoveexample.yml
@@ -104,3 +104,6 @@ graph:
 orphans:
   - "A.1.4"
   - "B.1.2"
+header:
+  firstChangeId: A.1.1
+  isWorkspace: false
diff --git a/testutils/threadbuilder/validsnapshotexample.yml b/testutils/threadbuilder/validsnapshotexample.yml
index 1fef3c35..9d5821ec 100644
--- a/testutils/threadbuilder/validsnapshotexample.yml
+++ b/testutils/threadbuilder/validsnapshotexample.yml
@@ -127,4 +127,7 @@ graph:
 orphans:
   - "A.1.3"
   - "B.1.2"
+header:
+  firstChangeId: A.1.1
+  isWorkspace: false
 
diff --git a/testutils/threadbuilder/ymlentities.go b/testutils/threadbuilder/ymlentities.go
index 68c7f3ac..c488ce0e 100644
--- a/testutils/threadbuilder/ymlentities.go
+++ b/testutils/threadbuilder/ymlentities.go
@@ -90,6 +90,11 @@ type Change struct {
 	ReadKey string `yaml:"readKey"`
 }
 
+type Header struct {
+	FirstChangeId string `yaml:"firstChangeId"`
+	IsWorkspace   bool   `yaml:"isWorkspace"`
+}
+
 type YMLThread struct {
 	Description    *ThreadDescription `yaml:"thread"`
 	Changes        []*Change          `yaml:"changes"`
@@ -102,4 +107,5 @@ type YMLThread struct {
 
 	Heads   []string `yaml:"heads"`
 	Orphans []string `yaml:"orphans"`
+	Header  *Header  `yaml:"header"`
 }