diff --git a/src/main/kotlin/ltd/hlaeja/service/DeviceService.kt b/src/main/kotlin/ltd/hlaeja/service/DeviceService.kt
new file mode 100644
index 0000000..88ff489
--- /dev/null
+++ b/src/main/kotlin/ltd/hlaeja/service/DeviceService.kt
@@ -0,0 +1,21 @@
+package ltd.hlaeja.service
+
+import java.time.ZonedDateTime
+import java.util.UUID
+import ltd.hlaeja.entity.DeviceEntity
+import ltd.hlaeja.repository.DeviceRepository
+import mu.KotlinLogging
+import org.springframework.stereotype.Service
+
+private val log = KotlinLogging.logger {}
+
+@Service
+class DeviceService(
+    private val deviceRepository: DeviceRepository,
+) {
+
+    suspend fun addDevice(
+        type: UUID,
+    ): DeviceEntity = deviceRepository.save(DeviceEntity(null, ZonedDateTime.now(), type))
+        .also { log.debug { "Added device ${it.id}" } }
+}
diff --git a/src/test/kotlin/ltd/hlaeja/service/DeviceServiceTest.kt b/src/test/kotlin/ltd/hlaeja/service/DeviceServiceTest.kt
new file mode 100644
index 0000000..b9ac546
--- /dev/null
+++ b/src/test/kotlin/ltd/hlaeja/service/DeviceServiceTest.kt
@@ -0,0 +1,60 @@
+package ltd.hlaeja.service
+
+import io.mockk.coEvery
+import io.mockk.coVerify
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.mockkStatic
+import io.mockk.unmockkStatic
+import java.time.Instant
+import java.time.ZoneId
+import java.time.ZonedDateTime
+import java.util.UUID
+import kotlinx.coroutines.test.runTest
+import ltd.hlaeja.entity.DeviceEntity
+import ltd.hlaeja.repository.DeviceRepository
+import org.junit.jupiter.api.AfterEach
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+
+class DeviceServiceTest {
+    companion object {
+        val timestamp = ZonedDateTime.ofInstant(Instant.parse("2000-01-01T00:00:00.001Z"), ZoneId.of("UTC"))
+
+        val device = UUID.fromString("00000000-0000-0000-0000-000000000001")
+        val type = UUID.fromString("00000000-0000-0000-0000-000000000002")
+    }
+
+    val repository: DeviceRepository = mockk()
+    lateinit var service: DeviceService
+
+    @BeforeEach
+    fun setUp() {
+        service = DeviceService(repository)
+
+        mockkStatic(ZonedDateTime::class)
+        every { ZonedDateTime.now() } returns timestamp
+    }
+
+    @AfterEach
+    fun tearDown() {
+        unmockkStatic(ZonedDateTime::class)
+    }
+
+    @Test
+    fun `add new type success`() = runTest {
+        // given
+        coEvery { repository.save(any()) } answers { call ->
+            (call.invocation.args[0] as DeviceEntity).copy(id = device)
+        }
+
+        // when
+        val result = service.addDevice(type)
+
+        // then
+        coVerify(exactly = 1) { repository.save(any()) }
+        kotlin.test.assertEquals(device, result.id)
+        kotlin.test.assertEquals("2000-01-01T00:00:00.001Z[UTC]", result.timestamp.toString())
+        kotlin.test.assertEquals(type, result.type)
+    }
+}