diff --git a/acltree/acltree.go b/acltree/acltree.go
index 46191d4c..82aa688c 100644
--- a/acltree/acltree.go
+++ b/acltree/acltree.go
@@ -54,7 +54,7 @@ type aclTree struct {
 	snapshotValidator *snapshotValidator
 	changeBuilder     *changeBuilder
 
-	sync.Mutex
+	sync.RWMutex
 }
 
 func BuildACLTree(
@@ -86,6 +86,7 @@ func BuildACLTree(
 	}
 	aclTree.removeOrphans()
 	t.SetHeads(aclTree.Heads())
+	listener.Rebuild(aclTree)
 
 	return aclTree, nil
 }
@@ -183,13 +184,19 @@ func (a *aclTree) rebuildFromThread(fromStart bool) error {
 }
 
 func (a *aclTree) ACLState() *ACLState {
+	a.RLock()
+	defer a.RUnlock()
 	return a.aclState
 }
 
 func (a *aclTree) AddContent(build func(builder ChangeBuilder) error) (*Change, error) {
 	// TODO: add snapshot creation logic
 	a.Lock()
-	defer a.Unlock()
+	defer func() {
+		a.Unlock()
+		// TODO: should this be called in a separate goroutine to prevent accidental cycles (tree->updater->tree)
+		a.updateListener.Update(a)
+	}()
 
 	a.changeBuilder.Init(a.aclState, a.fullTree, a.accountData)
 	err := build(a.changeBuilder)
@@ -213,13 +220,11 @@ func (a *aclTree) AddContent(build func(builder ChangeBuilder) error) (*Change,
 	}
 
 	a.thread.SetHeads([]string{ch.Id})
-	a.updateListener.Update(a)
 	return ch, nil
 }
 
 func (a *aclTree) AddChanges(changes ...*Change) (AddResult, error) {
 	a.Lock()
-	defer a.Unlock()
 	// TODO: make proper error handling, because there are a lot of corner cases where this will break
 	var err error
 	var mode Mode
@@ -230,6 +235,7 @@ func (a *aclTree) AddChanges(changes ...*Change) (AddResult, error) {
 		}
 		a.removeOrphans()
 		a.thread.SetHeads(a.fullTree.Heads())
+		a.Unlock()
 		switch mode {
 		case Append:
 			a.updateListener.Update(a)
@@ -286,20 +292,20 @@ func (a *aclTree) AddChanges(changes ...*Change) (AddResult, error) {
 }
 
 func (a *aclTree) Iterate(f func(change *Change) bool) {
-	a.Lock()
-	defer a.Unlock()
+	a.RLock()
+	defer a.RUnlock()
 	a.fullTree.Iterate(a.fullTree.RootId(), f)
 }
 
 func (a *aclTree) IterateFrom(s string, f func(change *Change) bool) {
-	a.Lock()
-	defer a.Unlock()
+	a.RLock()
+	defer a.RUnlock()
 	a.fullTree.Iterate(s, f)
 }
 
 func (a *aclTree) HasChange(s string) bool {
-	a.Lock()
-	defer a.Unlock()
+	a.RLock()
+	defer a.RUnlock()
 	_, attachedExists := a.fullTree.attached[s]
 	_, unattachedExists := a.fullTree.unAttached[s]
 	_, invalidExists := a.fullTree.invalidChanges[s]
@@ -307,13 +313,13 @@ func (a *aclTree) HasChange(s string) bool {
 }
 
 func (a *aclTree) Heads() []string {
-	a.Lock()
-	defer a.Unlock()
+	a.RLock()
+	defer a.RUnlock()
 	return a.fullTree.Heads()
 }
 
 func (a *aclTree) Root() *Change {
-	a.Lock()
-	defer a.Unlock()
+	a.RLock()
+	defer a.RUnlock()
 	return a.fullTree.Root()
 }
diff --git a/acltree/treebuilder.go b/acltree/treebuilder.go
index 944a44e1..1a34a3ae 100644
--- a/acltree/treebuilder.go
+++ b/acltree/treebuilder.go
@@ -169,6 +169,9 @@ func (tb *treeBuilder) findBreakpoint(heads []string) (breakpoint string, err er
 			return
 		}
 		shId := ch.SnapshotId
+		if ch.IsSnapshot {
+			shId = ch.Id
+		}
 		if slice.FindPos(snapshotIds, shId) == -1 {
 			snapshotIds = append(snapshotIds, shId)
 		}
diff --git a/plaintextdocument/document.go b/plaintextdocument/document.go
index 653388f9..63c07bde 100644
--- a/plaintextdocument/document.go
+++ b/plaintextdocument/document.go
@@ -23,7 +23,10 @@ type plainTextDocument struct {
 }
 
 func (p *plainTextDocument) Text() string {
-	return p.state.Text
+	if p.state != nil {
+		return p.state.Text
+	}
+	return ""
 }
 
 func (p *plainTextDocument) AddText(text string) error {
diff --git a/plaintextdocument/document_test.go b/plaintextdocument/document_test.go
index 0532240e..af596e54 100644
--- a/plaintextdocument/document_test.go
+++ b/plaintextdocument/document_test.go
@@ -1,53 +1,48 @@
 package plaintextdocument
 
-//
-//import (
-//	"github.com/anytypeio/go-anytype-infrastructure-experiments/testutils/threadbuilder"
-//	"github.com/stretchr/testify/assert"
-//	"testing"
-//)
-//
-//func TestDocument_Build(t *testing.T) {
-//	thread, err := threadbuilder.NewThreadBuilderWithTestName("threadbuilder/userjoinexample.yml")
-//	if err != nil {
-//		t.Fatal(err)
-//	}
-//	keychain := thread.GetKeychain()
-//	accountData := &AccountData{
-//		Identity: keychain.GetIdentity("A"),
-//		EncKey:   keychain.EncryptionKeys["A"],
-//	}
-//	doc := NewDocument(thread, NewPlainTextDocumentStateProvider(), accountData)
-//	res, err := doc.Build()
-//	if err != nil {
-//		t.Fatal(err)
-//	}
-//
-//	st := res.(*DocumentState)
-//	assert.Equal(t, st.Text, "some text|first")
-//}
-//
-//func TestDocument_Update(t *testing.T) {
-//	thread, err := threadbuilder.NewThreadBuilderWithTestName("threadbuilder/userjoinexample.yml")
-//	if err != nil {
-//		t.Fatal(err)
-//	}
-//	keychain := thread.GetKeychain()
-//	accountData := &AccountData{
-//		Identity: keychain.GetIdentity("A"),
-//		EncKey:   keychain.EncryptionKeys["A"],
-//	}
-//	doc := NewDocument(thread, NewPlainTextDocumentStateProvider(), accountData)
-//	res, err := doc.Build()
-//	if err != nil {
-//		t.Fatal(err)
-//	}
-//
-//	st := res.(*DocumentState)
-//	assert.Equal(t, st.Text, "some text|first")
-//
-//	rawChs := thread.GetUpdatedChanges()
-//	res, updateResult, err := doc.Update(rawChs...)
-//	assert.Equal(t, updateResult, UpdateResultAppend)
-//	assert.Equal(t, res.(*DocumentState).Text, "some text|first|second")
-//}
+import (
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/account"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/testutils/threadbuilder"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/thread"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestDocument_NewPlainTextDocument(t *testing.T) {
+	keychain := threadbuilder.NewKeychain()
+	keychain.AddSigningKey("A")
+	keychain.AddEncryptionKey("A")
+	data := &account.AccountData{
+		Identity: keychain.GetIdentity("A"),
+		SignKey:  keychain.SigningKeys["A"],
+		EncKey:   keychain.EncryptionKeys["A"],
+	}
+
+	doc, err := NewPlainTextDocument(data, thread.NewInMemoryThread, "Some text")
+	if err != nil {
+		t.Fatalf("should not create document with error: %v", err)
+	}
+	assert.Equal(t, doc.Text(), "Some text")
+}
+
+func TestDocument_PlainTextDocument_AddText(t *testing.T) {
+	keychain := threadbuilder.NewKeychain()
+	keychain.AddSigningKey("A")
+	keychain.AddEncryptionKey("A")
+	data := &account.AccountData{
+		Identity: keychain.GetIdentity("A"),
+		SignKey:  keychain.SigningKeys["A"],
+		EncKey:   keychain.EncryptionKeys["A"],
+	}
+
+	doc, err := NewPlainTextDocument(data, thread.NewInMemoryThread, "Some text")
+	if err != nil {
+		t.Fatalf("should not create document with error: %v", err)
+	}
+
+	err = doc.AddText("Next")
+	if err != nil {
+		t.Fatalf("should be able to add document: %v", err)
+	}
+	assert.Equal(t, doc.Text(), "Some text|Next")
+}