diff --git a/walkguide-backend/demo/src/test/java/com/walkguide/service/AiConfigServiceTest.java b/walkguide-backend/demo/src/test/java/com/walkguide/service/AiConfigServiceTest.java
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index 0000000..e077f46
--- /dev/null
+++ b/walkguide-backend/demo/src/test/java/com/walkguide/service/AiConfigServiceTest.java
@@ -0,0 +1,212 @@
+package com.walkguide.service;
+
+import com.walkguide.dto.request.AiConfigUpdateRequest;
+import com.walkguide.dto.response.AiConfigResponse;
+import com.walkguide.entity.AiConfig;
+import com.walkguide.entity.PairingRelation;
+import com.walkguide.entity.User;
+import com.walkguide.enums.PairingStatus;
+import com.walkguide.exception.PairingException;
+import com.walkguide.repository.AiConfigRepository;
+import com.walkguide.repository.PairingRelationRepository;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.*;
+import static org.mockito.Mockito.*;
+
+@ExtendWith(MockitoExtension.class)
+@DisplayName("AiConfigService Unit Tests")
+class AiConfigServiceTest {
+
+    @Mock AiConfigRepository aiConfigRepository;
+    @Mock PairingRelationRepository pairingRelationRepository;
+    @Mock FcmService fcmService;
+
+    @InjectMocks AiConfigService aiConfigService;
+
+    private User guardian;
+    private User user;
+    private PairingRelation activePairing;
+    private AiConfig existingConfig;
+
+    @BeforeEach
+    void setUp() {
+        guardian = User.builder()
+                .id(1L).email("guardian@test.com").role("ROLE_GUARDIAN")
+                .displayName("Guardian").fcmToken("guardian-fcm").build();
+
+        user = User.builder()
+                .id(2L).email("user@test.com").role("ROLE_USER")
+                .displayName("User").fcmToken("user-fcm").build();
+
+        activePairing = PairingRelation.builder()
+                .id(5L).guardian(guardian).user(user).status(PairingStatus.ACTIVE).build();
+
+        existingConfig = AiConfig.builder()
+                .id(10L).userId(2L).guardianId(1L)
+                .confidenceThreshold(0.5)
+                .alertDistanceClose(1.5)
+                .alertDistanceMedium(3.0)
+                .maxInferenceFps(5)
+                .build();
+    }
+
+    // ===== GET CONFIG TESTS =====
+
+    @Test
+    @DisplayName("getConfig - konfigurasi ada harus return data dari DB")
+    void getConfig_configExists_shouldReturnExistingConfig() {
+        when(aiConfigRepository.findByUserId(2L)).thenReturn(Optional.of(existingConfig));
+
+        AiConfigResponse result = aiConfigService.getConfig(2L);
+
+        assertThat(result.getId()).isEqualTo(10L);
+        assertThat(result.getConfidenceThreshold()).isEqualTo(0.5);
+        assertThat(result.getAlertDistanceClose()).isEqualTo(1.5);
+        verify(aiConfigRepository, never()).save(any());
+    }
+
+    @Test
+    @DisplayName("getConfig - konfigurasi belum ada harus buat default dan simpan")
+    void getConfig_configNotExists_shouldCreateDefaultAndSave() {
+        AiConfig newConfig = AiConfig.builder().id(99L).userId(2L).build();
+
+        when(aiConfigRepository.findByUserId(2L)).thenReturn(Optional.empty());
+        when(aiConfigRepository.save(any(AiConfig.class))).thenReturn(newConfig);
+
+        AiConfigResponse result = aiConfigService.getConfig(2L);
+
+        assertThat(result).isNotNull();
+        verify(aiConfigRepository).save(any(AiConfig.class));
+    }
+
+    // ===== UPDATE CONFIG BY GUARDIAN TESTS =====
+
+    @Test
+    @DisplayName("updateConfigByGuardian - update confidenceThreshold berhasil")
+    void updateConfigByGuardian_updateThreshold_shouldSaveAndNotify() {
+        AiConfigUpdateRequest req = new AiConfigUpdateRequest();
+        req.setConfidenceThreshold(0.75);
+
+        when(pairingRelationRepository.findByGuardian_IdAndStatus(1L, PairingStatus.ACTIVE))
+                .thenReturn(Optional.of(activePairing));
+        when(aiConfigRepository.findByUserId(2L)).thenReturn(Optional.of(existingConfig));
+        when(aiConfigRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        AiConfigResponse result = aiConfigService.updateConfigByGuardian(1L, req);
+
+        assertThat(result.getConfidenceThreshold()).isEqualTo(0.75);
+        verify(aiConfigRepository).save(any(AiConfig.class));
+        verify(fcmService).sendToToken(eq("user-fcm"), anyString(), anyString(), anyMap());
+    }
+
+    @Test
+    @DisplayName("updateConfigByGuardian - update semua field sekaligus")
+    void updateConfigByGuardian_updateAllFields_shouldUpdateAll() {
+        AiConfigUpdateRequest req = new AiConfigUpdateRequest();
+        req.setConfidenceThreshold(0.8);
+        req.setAlertDistanceClose(1.0);
+        req.setAlertDistanceMedium(2.5);
+        req.setMaxInferenceFps(10);
+        req.setEnabledLabels("person,car,motorcycle");
+
+        when(pairingRelationRepository.findByGuardian_IdAndStatus(1L, PairingStatus.ACTIVE))
+                .thenReturn(Optional.of(activePairing));
+        when(aiConfigRepository.findByUserId(2L)).thenReturn(Optional.of(existingConfig));
+        when(aiConfigRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        AiConfigResponse result = aiConfigService.updateConfigByGuardian(1L, req);
+
+        assertThat(result.getConfidenceThreshold()).isEqualTo(0.8);
+        assertThat(result.getAlertDistanceClose()).isEqualTo(1.0);
+        assertThat(result.getAlertDistanceMedium()).isEqualTo(2.5);
+        assertThat(result.getMaxInferenceFps()).isEqualTo(10);
+        assertThat(result.getEnabledLabels()).isEqualTo("person,car,motorcycle");
+    }
+
+    @Test
+    @DisplayName("updateConfigByGuardian - field null tidak boleh mengubah nilai existing")
+    void updateConfigByGuardian_nullFields_shouldNotOverrideExisting() {
+        // Request dengan semua field null — tidak ada yang berubah
+        AiConfigUpdateRequest req = new AiConfigUpdateRequest();
+
+        when(pairingRelationRepository.findByGuardian_IdAndStatus(1L, PairingStatus.ACTIVE))
+                .thenReturn(Optional.of(activePairing));
+        when(aiConfigRepository.findByUserId(2L)).thenReturn(Optional.of(existingConfig));
+        when(aiConfigRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        AiConfigResponse result = aiConfigService.updateConfigByGuardian(1L, req);
+
+        // Nilai lama tetap
+        assertThat(result.getConfidenceThreshold()).isEqualTo(0.5);
+        assertThat(result.getAlertDistanceClose()).isEqualTo(1.5);
+    }
+
+    @Test
+    @DisplayName("updateConfigByGuardian - Guardian tanpa pairing aktif harus throw PairingException")
+    void updateConfigByGuardian_noPairing_shouldThrow() {
+        when(pairingRelationRepository.findByGuardian_IdAndStatus(1L, PairingStatus.ACTIVE))
+                .thenReturn(Optional.empty());
+
+        assertThatThrownBy(() -> aiConfigService.updateConfigByGuardian(1L, new AiConfigUpdateRequest()))
+                .isInstanceOf(PairingException.class)
+                .hasMessageContaining("Tidak ada user yang dipair");
+
+        verify(aiConfigRepository, never()).save(any());
+        verify(fcmService, never()).sendToToken(any(), any(), any(), any());
+    }
+
+    @Test
+    @DisplayName("updateConfigByGuardian - konfigurasi belum ada harus buat baru lalu update")
+    void updateConfigByGuardian_configNotExists_shouldCreateAndUpdate() {
+        AiConfigUpdateRequest req = new AiConfigUpdateRequest();
+        req.setConfidenceThreshold(0.6);
+
+        AiConfig freshConfig = AiConfig.builder().userId(2L).guardianId(1L)
+                .confidenceThreshold(0.5).build();
+
+        when(pairingRelationRepository.findByGuardian_IdAndStatus(1L, PairingStatus.ACTIVE))
+                .thenReturn(Optional.of(activePairing));
+        // Pertama kali findByUserId kosong → save default → kembalikan freshConfig
+        when(aiConfigRepository.findByUserId(2L)).thenReturn(Optional.empty());
+        when(aiConfigRepository.save(any())).thenAnswer(inv -> {
+            AiConfig c = inv.getArgument(0);
+            c.setId(50L);
+            return c;
+        });
+
+        AiConfigResponse result = aiConfigService.updateConfigByGuardian(1L, req);
+
+        assertThat(result).isNotNull();
+        // save dipanggil 2x: sekali buat default, sekali update
+        verify(aiConfigRepository, times(2)).save(any(AiConfig.class));
+    }
+
+    @Test
+    @DisplayName("updateConfigByGuardian - harus kirim FCM ke user setelah update")
+    void updateConfigByGuardian_shouldSendFcmToUser() {
+        AiConfigUpdateRequest req = new AiConfigUpdateRequest();
+        req.setMaxInferenceFps(8);
+
+        when(pairingRelationRepository.findByGuardian_IdAndStatus(1L, PairingStatus.ACTIVE))
+                .thenReturn(Optional.of(activePairing));
+        when(aiConfigRepository.findByUserId(2L)).thenReturn(Optional.of(existingConfig));
+        when(aiConfigRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        aiConfigService.updateConfigByGuardian(1L, req);
+
+        ArgumentCaptor<String> tokenCaptor = ArgumentCaptor.forClass(String.class);
+        verify(fcmService).sendToToken(tokenCaptor.capture(), anyString(), anyString(), anyMap());
+        assertThat(tokenCaptor.getValue()).isEqualTo("user-fcm");
+    }
+}
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