diff --git a/.gitignore b/.gitignore
index 5a979af..9860ca8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -38,3 +38,6 @@ out/
 
 ### Kotlin ###
 .kotlin
+
+# simpler tests
+test_steering_signals.log
diff --git a/src/main/kotlin/com/frankenergie/smartasset/client/SteeringSignalClient.kt b/src/main/kotlin/com/frankenergie/smartasset/client/SteeringSignalClient.kt
new file mode 100644
index 0000000..e9e76f6
--- /dev/null
+++ b/src/main/kotlin/com/frankenergie/smartasset/client/SteeringSignalClient.kt
@@ -0,0 +1,39 @@
+package com.frankenergie.smartasset.client
+
+import com.frankenergie.smartasset.model.SteeringSignal
+import org.springframework.beans.factory.annotation.Value
+import org.springframework.stereotype.Component
+import java.nio.file.Files
+import java.nio.file.Path
+import java.nio.file.StandardOpenOption
+
+@Component
+class SteeringSignalClient(
+    @Value("\${steering.signals.file:steering_signals.log}") private val filePath: String
+) {
+    private val file: Path = Path.of(filePath)
+
+    init {
+        if (!Files.exists(file)) {
+            Files.createFile(file)
+        }
+    }
+
+    fun sendSignal(signal: SteeringSignal) {
+        val line = formatSignal(signal)
+        Files.writeString(file, "$line\n", StandardOpenOption.APPEND)
+    }
+
+    fun getAllSignals(): List<String> {
+        if (!Files.exists(file)) return emptyList()
+        return Files.readAllLines(file).filter { it.isNotBlank() }
+    }
+
+    fun clear() {
+        Files.writeString(file, "")
+    }
+
+    private fun formatSignal(signal: SteeringSignal): String {
+        return "${signal.timestamp}|${signal.groupId}|${signal.quarterStart}|${signal.quarterEnd}|${signal.chargePowerMW}"
+    }
+}
diff --git a/src/main/kotlin/com/frankenergie/smartasset/model/StreetingSignal.kt b/src/main/kotlin/com/frankenergie/smartasset/model/StreetingSignal.kt
new file mode 100644
index 0000000..523b3dd
--- /dev/null
+++ b/src/main/kotlin/com/frankenergie/smartasset/model/StreetingSignal.kt
@@ -0,0 +1,13 @@
+package com.frankenergie.smartasset.model
+
+import java.math.BigDecimal
+import java.time.Instant
+import java.time.LocalDateTime
+
+data class SteeringSignal(
+    val groupId: String,
+    val quarterStart: LocalDateTime,
+    val quarterEnd: LocalDateTime,
+    val chargePowerMW: BigDecimal,
+    val timestamp: Instant = Instant.now()
+)
diff --git a/src/test/kotlin/com/frankenergie/smartasset/client/SteeringSignalClientTest.kt b/src/test/kotlin/com/frankenergie/smartasset/client/SteeringSignalClientTest.kt
new file mode 100644
index 0000000..8a21ad5
--- /dev/null
+++ b/src/test/kotlin/com/frankenergie/smartasset/client/SteeringSignalClientTest.kt
@@ -0,0 +1,84 @@
+package com.frankenergie.smartasset.client
+
+import com.frankenergie.smartasset.model.SteeringSignal
+import org.junit.jupiter.api.AfterEach
+import org.junit.jupiter.api.Assertions.*
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import java.math.BigDecimal
+import java.nio.file.Files
+import java.nio.file.Path
+import java.time.LocalDateTime
+
+class SteeringSignalClientTest {
+
+    private val testFilePath = "./test_steering_signals.log"
+    private lateinit var client: SteeringSignalClient
+
+    @BeforeEach
+    fun setUp() {
+        Files.deleteIfExists(Path.of(testFilePath))
+        client = SteeringSignalClient(testFilePath)
+    }
+
+    @AfterEach
+    fun tearDown() {
+        Files.deleteIfExists(Path.of(testFilePath))
+    }
+
+    @Test
+    fun `sendSignal writes signal to file`() {
+        val signal = SteeringSignal(
+            groupId = "A",
+            quarterStart = LocalDateTime.of(2024, 1, 15, 10, 0),
+            quarterEnd = LocalDateTime.of(2024, 1, 15, 10, 15),
+            chargePowerMW = BigDecimal("2.0")
+        )
+
+        client.sendSignal(signal)
+
+        val lines = client.getAllSignals()
+        assertEquals(1, lines.size)
+        assertTrue(lines[0].contains("A"))
+        assertTrue(lines[0].contains("2.0"))
+    }
+
+    @Test
+    fun `multiple signals written on separate lines`() {
+        val signal1 = SteeringSignal(
+            "A",
+            LocalDateTime.of(2024, 1, 15, 10, 0),
+            LocalDateTime.of(2024, 1, 15, 10, 15),
+            BigDecimal("2.0")
+        )
+        val signal2 = SteeringSignal(
+            "B",
+            LocalDateTime.of(2024, 1, 15, 10, 15),
+            LocalDateTime.of(2024, 1, 15, 10, 30),
+            BigDecimal("3.0")
+        )
+
+        client.sendSignal(signal1)
+        client.sendSignal(signal2)
+
+        val lines = client.getAllSignals()
+        assertEquals(2, lines.size)
+        assertTrue(lines[0].contains("A"))
+        assertTrue(lines[1].contains("B"))
+    }
+
+    @Test
+    fun `clear removes all signals`() {
+        val signal = SteeringSignal(
+            "A",
+            LocalDateTime.of(2024, 1, 15, 10, 0),
+            LocalDateTime.of(2024, 1, 15, 10, 15),
+            BigDecimal("2.0")
+        )
+        client.sendSignal(signal)
+
+        client.clear()
+
+        assertTrue(client.getAllSignals().isEmpty())
+    }
+}