diff --git a/engine/core_test.go b/engine/core_test.go
new file mode 100644
index 000000000..07d9fed73
--- /dev/null
+++ b/engine/core_test.go
@@ -0,0 +1,53 @@
+/*
+Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
+Copyright (C) ITsysCOM GmbH
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>
+*/
+
+package engine
+
+import (
+	"testing"
+)
+
+func TestNewCoreService(t *testing.T) {
+	coreService := NewCoreService()
+	if coreService == nil {
+		t.Fatal("Expected non-nil *CoreService, got nil")
+	}
+	if _, ok := interface{}(coreService).(*CoreService); !ok {
+		t.Fatalf("Expected type *CoreService, got %T", coreService)
+	}
+}
+
+func TestListenAndServe(t *testing.T) {
+	coreService := &CoreService{}
+	exitChan := make(chan bool, 1)
+	go func() {
+		err := coreService.ListenAndServe(exitChan)
+		if err != nil {
+			t.Errorf("ListenAndServe returned an error: %v", err)
+		}
+	}()
+	exitChan <- true
+}
+
+func TestShutdown(t *testing.T) {
+	coreService := &CoreService{}
+	err := coreService.Shutdown()
+	if err != nil {
+		t.Errorf("Shutdown returned an error: %v", err)
+	}
+}
diff --git a/engine/libcdre_test.go b/engine/libcdre_test.go
new file mode 100644
index 000000000..75fee5069
--- /dev/null
+++ b/engine/libcdre_test.go
@@ -0,0 +1,46 @@
+/*
+Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
+Copyright (C) ITsysCOM GmbH
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>
+*/
+
+package engine
+
+import (
+	"testing"
+)
+
+func TestSetModule(t *testing.T) {
+	expEv := &ExportEvents{}
+	testModule := "newModuleValue"
+	expEv.SetModule(testModule)
+	if expEv.module != testModule {
+		t.Errorf("Expected module %s, got %s", testModule, expEv.module)
+	}
+}
+
+func TestAddEvent(t *testing.T) {
+	expEv := &ExportEvents{
+		Events: []any{},
+	}
+	event := "testEvent"
+	expEv.AddEvent(event)
+	if len(expEv.Events) != 1 {
+		t.Errorf("Expected 1 event, got %d", len(expEv.Events))
+	}
+	if expEv.Events[0] != event {
+		t.Errorf("Expected event %v, got %v", event, expEv.Events[0])
+	}
+}
diff --git a/engine/poster_test.go b/engine/poster_test.go
index d8fc7b8c4..0074fd47a 100644
--- a/engine/poster_test.go
+++ b/engine/poster_test.go
@@ -66,3 +66,52 @@ func TestKafkaParseURL(t *testing.T) {
 		t.Errorf("Expected: %s ,received: %s", utils.ToJSON(exp), utils.ToJSON(kfk))
 	}
 }
+
+func TestParseURL(t *testing.T) {
+	tests := []struct {
+		input       string
+		expectedURL string
+		expectedQID string
+		expectError bool
+	}{
+		{
+			input:       "http://cgrates.com/path?queue_id=myQueue",
+			expectedURL: "http://cgrates.com/path",
+			expectedQID: "myQueue",
+			expectError: false,
+		},
+		{
+			input:       "http://cgrates.com/path",
+			expectedURL: "http://cgrates.com/path",
+			expectedQID: defaultQueueID,
+			expectError: false,
+		},
+		{
+			input:       ":/invalid-url",
+			expectedURL: "",
+			expectedQID: "",
+			expectError: true,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.input, func(t *testing.T) {
+			url, qid, err := parseURL(test.input)
+			if test.expectError {
+				if err == nil {
+					t.Fatalf("Expected error, got nil")
+				}
+			} else {
+				if err != nil {
+					t.Fatalf("Expected no error, got %v", err)
+				}
+				if url != test.expectedURL {
+					t.Fatalf("Expected URL to be %v, got %v", test.expectedURL, url)
+				}
+				if qid != test.expectedQID {
+					t.Fatalf("Expected qID to be %v, got %v", test.expectedQID, qid)
+				}
+			}
+		})
+	}
+}
diff --git a/engine/responder_test.go b/engine/responder_test.go
index d7dab513b..87f775286 100644
--- a/engine/responder_test.go
+++ b/engine/responder_test.go
@@ -1282,3 +1282,31 @@ func TestResponderGetMaxSessionTimeOnAccounts(t *testing.T) {
 	}
 	//
 }
+
+func TestResponderPing(t *testing.T) {
+	var r Responder
+	var reply string
+	err := r.Ping(nil, &reply)
+	if err != nil {
+		t.Fatalf("Expected no error, got %v", err)
+	}
+	if reply != utils.Pong {
+		t.Fatalf("Expected reply to be %s, got %s", utils.Pong, reply)
+	}
+}
+
+func TestResponderSetMaxComputedUsage(t *testing.T) {
+	r := &Responder{
+		MaxComputedUsage: make(map[string]time.Duration),
+	}
+	newMaxComputedUsage := map[string]time.Duration{
+		"user1": 5 * time.Hour,
+		"user2": 3 * time.Hour,
+	}
+	r.SetMaxComputedUsage(newMaxComputedUsage)
+	r.maxComputedUsageMutex.RLock()
+	defer r.maxComputedUsageMutex.RUnlock()
+	if !reflect.DeepEqual(r.MaxComputedUsage, newMaxComputedUsage) {
+		t.Fatalf("Expected MaxComputedUsage to be %v, got %v", newMaxComputedUsage, r.MaxComputedUsage)
+	}
+}