diff --git a/app/src/main/java/com/geeksville/mesh/model/UIState.kt b/app/src/main/java/com/geeksville/mesh/model/UIState.kt
index c97b38847..8b0029a17 100644
--- a/app/src/main/java/com/geeksville/mesh/model/UIState.kt
+++ b/app/src/main/java/com/geeksville/mesh/model/UIState.kt
@@ -28,6 +28,7 @@ import com.geeksville.mesh.database.entity.QuickChatAction
 import com.geeksville.mesh.repository.datastore.RadioConfigRepository
 import com.geeksville.mesh.repository.radio.RadioInterfaceService
 import com.geeksville.mesh.service.MeshService
+import com.geeksville.mesh.service.ServiceAction
 import com.geeksville.mesh.ui.map.MAP_STYLE_ID
 import com.geeksville.mesh.util.positionToMeter
 import dagger.hilt.android.lifecycle.HiltViewModel
@@ -383,6 +384,12 @@ class UIViewModel @Inject constructor(
         }
     }
 
+    fun sendTapback(emoji: String, replyId: Int, contactKey: String) {
+        viewModelScope.launch {
+            radioConfigRepository.onServiceAction(ServiceAction.Tapback(emoji, replyId, contactKey))
+        }
+    }
+
     fun requestTraceroute(destNum: Int) {
         info("Requesting traceroute for '$destNum'")
         try {
diff --git a/app/src/main/java/com/geeksville/mesh/repository/datastore/RadioConfigRepository.kt b/app/src/main/java/com/geeksville/mesh/repository/datastore/RadioConfigRepository.kt
index 36d6dbb65..7e0af44ce 100644
--- a/app/src/main/java/com/geeksville/mesh/repository/datastore/RadioConfigRepository.kt
+++ b/app/src/main/java/com/geeksville/mesh/repository/datastore/RadioConfigRepository.kt
@@ -16,6 +16,7 @@ import com.geeksville.mesh.deviceProfile
 import com.geeksville.mesh.model.NodeDB
 import com.geeksville.mesh.model.getChannelUrl
 import com.geeksville.mesh.service.MeshService.ConnectionState
+import com.geeksville.mesh.service.ServiceAction
 import com.geeksville.mesh.service.ServiceRepository
 import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.flow.Flow
@@ -177,6 +178,12 @@ class RadioConfigRepository @Inject constructor(
         serviceRepository.emitMeshPacket(packet)
     }
 
+    val serviceAction: SharedFlow<ServiceAction> get() = serviceRepository.serviceAction
+
+    suspend fun onServiceAction(action: ServiceAction) = coroutineScope {
+        serviceRepository.onServiceAction(action)
+    }
+
     val tracerouteResponse: StateFlow<String?> get() = serviceRepository.tracerouteResponse
 
     fun setTracerouteResponse(value: String?) {
diff --git a/app/src/main/java/com/geeksville/mesh/service/MeshService.kt b/app/src/main/java/com/geeksville/mesh/service/MeshService.kt
index a191f1258..9279c9614 100644
--- a/app/src/main/java/com/geeksville/mesh/service/MeshService.kt
+++ b/app/src/main/java/com/geeksville/mesh/service/MeshService.kt
@@ -58,6 +58,10 @@ import java.util.concurrent.TimeoutException
 import javax.inject.Inject
 import kotlin.math.absoluteValue
 
+sealed class ServiceAction {
+    data class Tapback(val emoji: String, val replyId: Int, val contactKey: String) : ServiceAction()
+}
+
 /**
  * Handles all the communication with android apps.  Also keeps an internal model
  * of the network state.
@@ -279,6 +283,11 @@ class MeshService : Service(), Logging {
             .launchIn(serviceScope)
         radioConfigRepository.channelSetFlow.onEach { channelSet = it }
             .launchIn(serviceScope)
+        radioConfigRepository.serviceAction.onEach { action ->
+            when (action) {
+                is ServiceAction.Tapback -> sendTapback(action)
+            }
+        }.launchIn(serviceScope)
 
         loadSettings() // Load our last known node DB
 
@@ -1724,6 +1733,21 @@ class MeshService : Service(), Logging {
         }
     }
 
+    private fun sendTapback(tapback: ServiceAction.Tapback) = toRemoteExceptions {
+        // contactKey: unique contact key filter (channel)+(nodeId)
+        val channel = tapback.contactKey[0].digitToInt()
+        val destNum = tapback.contactKey.substring(1)
+
+        sendToRadio(newMeshPacketTo(destNum).buildMeshPacket(
+            channel = channel,
+            priority = MeshPacket.Priority.BACKGROUND,
+        ) {
+            replyId = tapback.replyId
+            portnumValue = Portnums.PortNum.TEXT_MESSAGE_APP_VALUE
+            payload = ByteString.copyFrom(tapback.emoji.encodeToByteArray())
+        })
+    }
+
     private val binder = object : IMeshService.Stub() {
 
         override fun setDeviceAddress(deviceAddr: String?) = toRemoteExceptions {
diff --git a/app/src/main/java/com/geeksville/mesh/service/ServiceRepository.kt b/app/src/main/java/com/geeksville/mesh/service/ServiceRepository.kt
index c1fea6773..9ebe8b649 100644
--- a/app/src/main/java/com/geeksville/mesh/service/ServiceRepository.kt
+++ b/app/src/main/java/com/geeksville/mesh/service/ServiceRepository.kt
@@ -68,4 +68,11 @@ class ServiceRepository @Inject constructor() : Logging {
     fun clearTracerouteResponse() {
         setTracerouteResponse(null)
     }
+
+    private val _serviceAction = MutableSharedFlow<ServiceAction>()
+    val serviceAction: SharedFlow<ServiceAction> get() = _serviceAction
+
+    suspend fun onServiceAction(action: ServiceAction) {
+        _serviceAction.emit(action)
+    }
 }