diff --git a/native/profile/secondary-device-qr-code-scanner.react.js b/native/profile/secondary-device-qr-code-scanner.react.js
--- a/native/profile/secondary-device-qr-code-scanner.react.js
+++ b/native/profile/secondary-device-qr-code-scanner.react.js
@@ -2,10 +2,27 @@
 
 import { useNavigation } from '@react-navigation/native';
 import { BarCodeScanner, type BarCodeEvent } from 'expo-barcode-scanner';
+import invariant from 'invariant';
 import * as React from 'react';
 import { View } from 'react-native';
 
 import { parseDataFromDeepLink } from 'lib/facts/links.js';
+import { IdentityClientContext } from 'lib/shared/identity-client-context.js';
+import { useTunnelbroker } from 'lib/tunnelbroker/tunnelbroker-context.js';
+import type { RawDeviceList } from 'lib/types/identity-service-types.js';
+import {
+  tunnelbrokerMessageTypes,
+  type TunnelbrokerMessage,
+} from 'lib/types/tunnelbroker/messages.js';
+import {
+  peerToPeerMessageTypes,
+  type PeerToPeerMessage,
+} from 'lib/types/tunnelbroker/peer-to-peer-message-types.js';
+import { qrCodeAuthMessageTypes } from 'lib/types/tunnelbroker/qr-code-auth-message-types.js';
+import {
+  createQRAuthTunnelbrokerMessage,
+  parseQRAuthTunnelbrokerMessage,
+} from 'lib/utils/qr-code-auth.js';
 
 import type { ProfileNavigationProp } from './profile.react.js';
 import type { NavigationRoute } from '../navigation/route-names.js';
@@ -29,6 +46,9 @@
   const tunnelbrokerContext = useTunnelbroker();
   const identityContext = React.useContext(IdentityClientContext);
 
+  const aes256Key = React.useRef<?string>(null);
+  const secondaryDeviceID = React.useRef<?string>(null);
+
   const addDeviceToList = React.useCallback(
     async (newDeviceID: string) => {
       invariant(identityContext, 'identity context not set');
@@ -69,6 +89,45 @@
     [identityContext],
   );
 
+  const tunnelbrokerMessageListener = React.useCallback(
+    async (message: TunnelbrokerMessage) => {
+      const encryptionKey = aes256Key.current;
+      const targetDeviceID = secondaryDeviceID.current;
+      if (!encryptionKey || !targetDeviceID) {
+        return;
+      }
+      if (message.type !== tunnelbrokerMessageTypes.MESSAGE_TO_DEVICE) {
+        return;
+      }
+
+      const innerMessage: PeerToPeerMessage = JSON.parse(message.payload);
+      if (innerMessage.type !== peerToPeerMessageTypes.QR_CODE_AUTH_MESSAGE) {
+        return;
+      }
+
+      const payload = parseQRAuthTunnelbrokerMessage(
+        encryptionKey,
+        innerMessage,
+      );
+      if (
+        payload?.type !==
+        qrCodeAuthMessageTypes.SECONDARY_DEVICE_REGISTRATION_SUCCESS
+      ) {
+        return;
+      }
+      Alert.alert('Device added', `It worked`, [{ text: 'OK' }]);
+    },
+    [tunnelbrokerContext],
+  );
+
+  React.useEffect(() => {
+    tunnelbrokerContext.addListener(tunnelbrokerMessageListener);
+
+    return () => {
+      tunnelbrokerContext.removeListener(tunnelbrokerMessageListener);
+    };
+  }, [tunnelbrokerMessageListener, tunnelbrokerContext]);
+
   React.useEffect(() => {
     void (async () => {
       const { status } = await BarCodeScanner.requestPermissionsAsync();
@@ -103,6 +162,8 @@
 
       const keys = JSON.parse(decodeURIComponent(keysMatch));
       const { aes256, ed25519 } = keys;
+      aes256Key.current = aes256;
+      secondaryDeviceID.current = ed25519;
 
       void (async () => {
         try {
@@ -133,12 +194,7 @@
         }
       })();
     },
-    [
-      tunnelbrokerContext,
-      addDeviceToList,
-      identityContext,
-      navigation,
-    ],
+    [tunnelbrokerContext, addDeviceToList, identityContext, navigation],
   );
 
   const onCancelScan = React.useCallback(() => setScanned(false), []);
diff --git a/native/qr-code/qr-code-screen.react.js b/native/qr-code/qr-code-screen.react.js
--- a/native/qr-code/qr-code-screen.react.js
+++ b/native/qr-code/qr-code-screen.react.js
@@ -42,6 +42,7 @@
   const [qrCodeValue, setQrCodeValue] = React.useState<?string>();
   const [deviceKeys, setDeviceKeys] =
     React.useState<?{ +deviceID: string, +aesKey: string }>();
+  const [primaryDeviceID, setPrimaryDeviceID] = React.useState<?string>();
   const {
     setUnauthorizedDeviceID,
     addListener,
@@ -53,6 +54,29 @@
   const identityContext = React.useContext(IdentityClientContext);
   const identityClient = identityContext?.identityClient;
 
+  React.useEffect(() => {
+    if (
+      !(tunnelbrokerConnected && isAuthorized && primaryDeviceID && deviceKeys)
+    ) {
+      return;
+    }
+
+    const message = createQRAuthTunnelbrokerMessage(deviceKeys.aesKey, {
+      type: qrCodeAuthMessageTypes.SECONDARY_DEVICE_REGISTRATION_SUCCESS,
+    });
+    console.log('SECONDARY MESSAGE', message);
+    void sendMessage({
+      deviceID: primaryDeviceID,
+      payload: JSON.stringify(message),
+    });
+  }, [
+    tunnelbrokerConnected,
+    isAuthorized,
+    sendMessage,
+    primaryDeviceID,
+    deviceKeys,
+  ]);
+
   const tunnelbrokerMessageListener = React.useCallback(
     async (message: TunnelbrokerMessage) => {
       invariant(identityClient, 'identity context not set');
@@ -78,7 +102,9 @@
       ) {
         return;
       }
-      const { userID } = qrCodeAuthMessage;
+      const { primaryDeviceID: receivedPrimaryDeviceID, userID } =
+        qrCodeAuthMessage;
+      setPrimaryDeviceID(receivedPrimaryDeviceID);
 
       try {
         const nonce = await identityClient.generateNonce();