diff --git a/internal/service/agent_sessions.go b/internal/service/agent_sessions.go
index d5adc10f1d..4bb8ccd525 100644
--- a/internal/service/agent_sessions.go
+++ b/internal/service/agent_sessions.go
@@ -700,6 +700,21 @@ func (s *AgentService) CreateAgentSession(ctx context.Context, req *CreateAgentS
 		return nil, common.CodeDataError, err
 	}
 
+	// Resolve the latest version title so the session records which version it
+	// belongs to. GetLatest mirrors the RunAgent path and Python's
+	// release_mode=false lookup; a canvas without any version row yet is a
+	// normal state and leaves the title nil.
+	var versionTitle *string
+	if s.versionDAO != nil {
+		versionRow, verr := s.versionDAO.GetLatest(ctx, dao.DB, req.AgentID)
+		if verr != nil && !errors.Is(verr, dao.ErrUserCanvasVersionNotFound) {
+			return nil, common.CodeServerError, fmt.Errorf("load latest version title: %w", verr)
+		}
+		if versionRow != nil {
+			versionTitle = versionRow.Title
+		}
+	}
+
 	name := strings.TrimSpace(req.Name)
 	if name == "" {
 		name = "session"
@@ -716,15 +731,16 @@ func (s *AgentService) CreateAgentSession(ctx context.Context, req *CreateAgentS
 	// by entity.BaseModel.BeforeCreate when the DAO Create() call runs,
 	// so we do not set them explicitly here.
 	row := &entity.API4Conversation{
-		ID:        id,
-		Name:      namePtr,
-		DialogID:  req.AgentID,
-		UserID:    req.UserID,
-		ExpUserID: &req.UserID,
-		Message:   messages,
-		Reference: reference,
-		Source:    sourcePtr,
-		DSL:       dsl,
+		ID:           id,
+		Name:         namePtr,
+		DialogID:     req.AgentID,
+		UserID:       req.UserID,
+		ExpUserID:    &req.UserID,
+		Message:      messages,
+		Reference:    reference,
+		Source:       sourcePtr,
+		DSL:          dsl,
+		VersionTitle: versionTitle,
 	}
 	if err := s.api4ConversationDAO.Create(ctx, dao.DB, row); err != nil {
 		return nil, common.CodeServerError, fmt.Errorf("create agent session: %w", err)
diff --git a/internal/service/agent_test.go b/internal/service/agent_test.go
index fa136015ac..ff1b5adad4 100644
--- a/internal/service/agent_test.go
+++ b/internal/service/agent_test.go
@@ -1049,6 +1049,129 @@ func TestGetAgentSessionServiceSuccess(t *testing.T) {
 	}
 }
 
+func TestCreateAgentSessionWritesLatestVersionTitle(t *testing.T) {
+	setupAgentSessionServiceTest(t)
+
+	createAgentSessionTestCanvas(t, "canvas-1", "user-1")
+
+	now := time.Now()
+	if err := dao.DB.Create(&entity.UserCanvasVersion{
+		ID:           "version-old",
+		UserCanvasID: "canvas-1",
+		Title:        sptr("owner_Test Agent_old"),
+		BaseModel: entity.BaseModel{
+			CreateTime: ptr(now.Add(-time.Hour).UnixMilli()),
+			UpdateTime: ptr(now.Add(-time.Hour).UnixMilli()),
+		},
+	}).Error; err != nil {
+		t.Fatalf("failed to create old version: %v", err)
+	}
+	if err := dao.DB.Create(&entity.UserCanvasVersion{
+		ID:           "version-newest",
+		UserCanvasID: "canvas-1",
+		Title:        sptr("owner_Test Agent_newest"),
+		BaseModel: entity.BaseModel{
+			CreateTime: ptr(now.UnixMilli()),
+			UpdateTime: ptr(now.UnixMilli()),
+		},
+	}).Error; err != nil {
+		t.Fatalf("failed to create newest version: %v", err)
+	}
+
+	ctx := t.Context()
+	svc := NewAgentService()
+	session, code, err := svc.CreateAgentSession(ctx, &CreateAgentSessionRequest{
+		UserID:  "user-1",
+		AgentID: "canvas-1",
+		Name:    "hello",
+	})
+	if err != nil {
+		t.Fatalf("CreateAgentSession failed: %v", err)
+	}
+	if code != common.CodeSuccess {
+		t.Fatalf("expected code %d, got %d", common.CodeSuccess, code)
+	}
+	if session.VersionTitle == nil {
+		t.Fatal("expected version_title to be set")
+	}
+	if *session.VersionTitle != "owner_Test Agent_newest" {
+		t.Fatalf("expected newest version title, got %q", *session.VersionTitle)
+	}
+
+	stored, err := dao.NewAPI4ConversationDAO().GetMetadataBySessionID(ctx, dao.DB, session.ID, "canvas-1")
+	if err != nil {
+		t.Fatalf("failed to reload session: %v", err)
+	}
+	if stored == nil || stored.VersionTitle == nil {
+		t.Fatalf("expected persisted version_title, got %+v", stored)
+	}
+	if *stored.VersionTitle != "owner_Test Agent_newest" {
+		t.Fatalf("expected persisted newest title, got %q", *stored.VersionTitle)
+	}
+
+	// The list surface used by the agent log page must expose it too.
+	resp, code, err := svc.ListAgentSessions(ctx, "user-1", "user-1", "canvas-1", ListAgentSessionsRequest{Page: 1, PageSize: 10})
+	if err != nil {
+		t.Fatalf("ListAgentSessions failed: %v", err)
+	}
+	if code != common.CodeSuccess {
+		t.Fatalf("expected code %d, got %d", common.CodeSuccess, code)
+	}
+	if len(resp.Data) != 1 {
+		t.Fatalf("expected 1 session, got %d", len(resp.Data))
+	}
+	listed, _ := resp.Data[0]["version_title"].(*string)
+	if listed == nil || *listed != "owner_Test Agent_newest" {
+		t.Fatalf("expected list version_title newest, got %v", resp.Data[0]["version_title"])
+	}
+}
+
+func TestCreateAgentSessionNoVersionLeavesTitleNil(t *testing.T) {
+	setupAgentSessionServiceTest(t)
+
+	createAgentSessionTestCanvas(t, "canvas-1", "user-1")
+
+	ctx := t.Context()
+	session, code, err := NewAgentService().CreateAgentSession(ctx, &CreateAgentSessionRequest{
+		UserID:  "user-1",
+		AgentID: "canvas-1",
+	})
+	if err != nil {
+		t.Fatalf("CreateAgentSession failed: %v", err)
+	}
+	if code != common.CodeSuccess {
+		t.Fatalf("expected code %d, got %d", common.CodeSuccess, code)
+	}
+	if session.VersionTitle != nil {
+		t.Fatalf("expected nil version_title, got %q", *session.VersionTitle)
+	}
+}
+
+func TestCreateAgentSessionVersionLookupErrorReturnsServerError(t *testing.T) {
+	setupAgentSessionServiceTest(t)
+
+	createAgentSessionTestCanvas(t, "canvas-1", "user-1")
+
+	if err := dao.DB.Exec("DROP TABLE user_canvas_version").Error; err != nil {
+		t.Fatalf("failed to drop user_canvas_version: %v", err)
+	}
+
+	ctx := t.Context()
+	session, code, err := NewAgentService().CreateAgentSession(ctx, &CreateAgentSessionRequest{
+		UserID:  "user-1",
+		AgentID: "canvas-1",
+	})
+	if err == nil {
+		t.Fatal("expected version lookup error")
+	}
+	if code != common.CodeServerError {
+		t.Fatalf("expected code %d, got %d", common.CodeServerError, code)
+	}
+	if session != nil {
+		t.Fatalf("expected nil session, got %+v", session)
+	}
+}
+
 func TestGetAgentSessionServiceNotFoundWhenSessionBelongsToAnotherAgent(t *testing.T) {
 	setupAgentSessionServiceTest(t)