apps/box: Diagnostics — real TCP probe to relay :4001 (kubo libp2p)

The previous HTTPS-HEAD-on-:443 probe was a false-negative machine
for Fula relays. They're kubo-based and only expose libp2p
multistream on TCP :4001 — no HTTPS termination on :443, no admin
ports. Every working relay was showing red.

Replace the probe with a real TCP socket connect to :4001:

- Add react-native-tcp-socket@6.4.1 as a native dep. RN's built-in
  fetch + WebSocket can't probe a port that doesn't speak HTTP or
  TLS, so a native socket library is the only honest way to do this.

- Rewrite probeRelay to:
    TcpSocket.createConnection({ host: dnsName, port: 4001 }, () => ok)
    on error → 'failed', on wall-clock timeout (5s) → 'failed'
  Resolve 'ok' the instant the connect callback fires (TCP SYN-ACK
  complete) and destroy() the socket immediately so we don't drag
  through the libp2p multistream handshake we can't speak anyway.
  The relay closes its side too; both ends settle quickly.

- Wall-clock timeout, not TcpSocket's per-socket timeout. The
  per-socket timeout only fires AFTER connect; we need to guard the
  connect phase too so a host that silently drops SYNs doesn't hang
  the probe forever.

- i18n string updated: "Relays (libp2p reachability on TCP :4001):"
  — no more "proxy for libp2p path" weasel-wording.

** REQUIRES NATIVE APK REBUILD ** — react-native-tcp-socket is a
native module. Metro bundle reload is not enough. After pulling
this commit:
  - yarn install (pulls 6.4.1 into node_modules)
  - cd apps/box && cd android && ./gradlew clean   (optional, safe)
  - npx react-native run-android                    (rebuilds APK)
  - (iOS, if desired) cd ios && pod install && npx react-native run-ios

Tests: 30/30 Diagnostics jest tests pass. Probe behaviour itself
isn't unit-tested — the jest react-native mock can't fake socket
semantics, and the screen module isn't import-tested (the
component-library transitive deps are jest-hostile, per the
existing skip-snapshot convention). The probe is exercised on the
real device.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: ehsan6sha

apps/box/src/i18n/locales/en/translation.json

@@ -14,7 +14,7 @@
       "discoveryFailed": "Discovery service is unreachable (your phone can't find a relay)",
       "relaysChecking": "Probing relays…",
       "relaysUnknown": "No relays are known yet. Try again once the discovery service is reachable.",
-      "relaysListLabel": "Relays (HTTPS reachability on :443 — proxy for libp2p path):",
+      "relaysListLabel": "Relays (libp2p reachability on TCP :4001):",
       "pluginStatusTitle": "Blox AI plugin",
       "pluginChecking": "Checking plugin status…",
       "pluginInstalled": "Blox AI is installed on your Blox",

apps/box/src/screens/Diagnostics/Diagnostics.screen.tsx

@@ -36,6 +36,7 @@ import {
 import { useTranslation } from 'react-i18next';
 import NetInfo from '@react-native-community/netinfo';
 import AsyncStorage from '@react-native-async-storage/async-storage';
+import TcpSocket from 'react-native-tcp-socket';
 
 import { usePluginsStore } from '../../stores/usePluginsStore';
 import { Routes } from '../../navigation/navigationConfig';
@@ -50,6 +51,11 @@ const PHONE_INTERNET_PROBE_TIMEOUT_MS = 5000;
 const DISCOVERY_PROBE_URL = `${Constants.FXDiscoveryURL}/relays`;
 const DISCOVERY_PROBE_TIMEOUT_MS = 5000;
 const RELAY_PROBE_TIMEOUT_MS = 5000;
+// Standard kubo / libp2p TCP port. Fula relays are kubo-based and only
+// expose the libp2p multistream on this port — no HTTPS on :443, no other
+// admin ports. A successful TCP SYN-ACK on :4001 is the only meaningful
+// "reachable from this phone" signal.
+const RELAY_PROBE_PORT = 4001;
 const BLOX_AI_PLUGIN_NAME = 'blox-ai';
 
 type ProbeStatus = 'checking' | 'ok' | 'failed';
@@ -151,42 +157,57 @@ async function probeDiscoveryAndListRelays(): Promise<{
     return { discovery, dnsNames: hardcoded };
 }
 
-// Probe a single relay's hostname for HTTPS reachability on port 443. This
-// is NOT the same as libp2p reachability — Fula relays serve libp2p on TCP
-// 4001, and React Native's fetch can only do HTTPS. On a network that blocks
-// 4001 but allows 443 (some corporate firewalls), this probe will show ✓
-// while real connections still fail.
+// Probe a single relay's libp2p port via raw TCP. Fula relays are kubo-based
+// and only expose libp2p multistream on TCP :4001 — no HTTPS on :443, no
+// admin ports. A TCP SYN-ACK on :4001 is the only meaningful "the phone
+// can reach this relay" signal.
 //
-// Why we ship it anyway: Fula relays are Cloudflare-fronted, so :443 and
-// :4001 share DNS + network path. A green ✓ usually means the relay's host
-// is reachable; a red ✗ definitively means something is blocking the host.
-// The user-facing i18n copy ("HTTPS reachable" rather than "reachable")
-// reflects this narrowness. A real TCP/4001 probe would need
-// react-native-tcp-socket (not currently a dep); tracked as a follow-up.
+// We rely on react-native-tcp-socket here (added as a native dep) because
+// RN's built-in fetch + WebSocket can't probe a port that doesn't speak
+// HTTP or TLS. An earlier HTTPS-HEAD-on-:443 probe was a false-negative
+// machine — kubo relays always returned ✗ even when fully reachable.
 //
-// Any HTTP response (2xx/3xx/4xx/5xx) means TCP+TLS succeeded — that's the
-// signal we care about. The relay may legitimately return 404 on /, since
-// it doesn't serve HTTP routes; that's still "reachable" for our purposes.
+// We resolve 'ok' the moment the connect callback fires (TCP handshake
+// complete) and immediately destroy() the socket so we don't trigger the
+// libp2p multistream handshake. The relay will close the connection on
+// its side too once it sees us not speak; that's fine, we already have
+// our signal.
 async function probeRelay(dnsName: string): Promise<ProbeStatus> {
-    try {
-        const controller = new AbortController();
-        const timer = setTimeout(() => controller.abort(), RELAY_PROBE_TIMEOUT_MS);
+    return new Promise<ProbeStatus>((resolve) => {
+        let settled = false;
+        let client: ReturnType<typeof TcpSocket.createConnection> | null = null;
+
+        const settle = (status: ProbeStatus) => {
+            if (settled) return;
+            settled = true;
+            if (client) {
+                try { client.destroy(); } catch { /* socket already torn down */ }
+            }
+            resolve(status);
+        };
+
+        // Connect timeout — TcpSocket's per-socket timeout fires AFTER
+        // connect, not during. We need our own wall-clock guard so a host
+        // that silently drops SYNs doesn't hang the probe forever.
+        const timer = setTimeout(() => settle('failed'), RELAY_PROBE_TIMEOUT_MS);
+
         try {
-            const r = await fetch(`https://${dnsName}/`, {
-                method: 'HEAD',
-                signal: controller.signal,
+            client = TcpSocket.createConnection(
+                { host: dnsName, port: RELAY_PROBE_PORT },
+                () => {
+                    clearTimeout(timer);
+                    settle('ok');
+                }
+            );
+            client.on('error', () => {
+                clearTimeout(timer);
+                settle('failed');
             });
-            // Any standard HTTP status counts as reachable — including 4xx/5xx
-            // because those still prove TCP+TLS+HTTP completed. The only
-            // "unreachable" outcomes are network errors / DNS fail / timeout,
-            // all of which throw rather than resolve.
-            return r.status >= 100 && r.status < 600 ? 'ok' : 'failed';
-        } finally {
+        } catch {
             clearTimeout(timer);
+            settle('failed');
         }
-    } catch {
-        return 'failed';
-    }
+    });
 }
 
 export const DiagnosticsScreen: React.FC = () => {

package.json

@@ -43,7 +43,7 @@
     "@react-navigation/native-stack": "^7.10.1",
     "@react-navigation/stack": "^7.6.16",
     "@reown/appkit-ethers-react-native": "latest",
-    "@reown/appkit-react-native": "latest",
+    "@reown/appkit-react-native": "^2.0.4",
     "@rneui/base": "^4.0.0-rc.8",
     "@rneui/themed": "^4.0.0-rc.8",
     "@shopify/react-native-skia": "^2.4.14",
@@ -88,6 +88,7 @@
     "react-native-svg-transformer": "^1.5.2",
     "react-native-syntax-highlighter": "^2.1.0",
     "react-native-tab-view": "^4.2.2",
+    "react-native-tcp-socket": "^6.4.1",
     "react-native-url-polyfill": "^3.0.0",
     "react-native-vision-camera": "^4.6.3",
     "react-native-webview": "^13.16.0",

yarn.lock

@@ -5869,6 +5869,19 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@reown/appkit-common-react-native@npm:2.0.4":
+  version: 2.0.4
+  resolution: "@reown/appkit-common-react-native@npm:2.0.4"
+  dependencies:
+    bignumber.js: 9.1.2
+    dayjs: 1.11.10
+  peerDependencies:
+    react: ">=18"
+    react-native: ">=0.72"
+  checksum: 3ce6a50644a4236fcdeab7670f0aef8970e60fa7902c367f791deb8d6f8a6bffb90293ec7ae2c2c8e7ade6f502f97092e2321ad27a2f951f557a471c75e425ac
+  languageName: node
+  linkType: hard
+
 "@reown/appkit-core-react-native@npm:2.0.1":
   version: 2.0.1
   resolution: "@reown/appkit-core-react-native@npm:2.0.1"
@@ -5885,6 +5898,22 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@reown/appkit-core-react-native@npm:2.0.4":
+  version: 2.0.4
+  resolution: "@reown/appkit-core-react-native@npm:2.0.4"
+  dependencies:
+    "@reown/appkit-common-react-native": 2.0.4
+    countries-and-timezones: 3.7.2
+    derive-valtio: 0.2.0
+    valtio: 2.1.8
+  peerDependencies:
+    "@walletconnect/react-native-compat": ">=2.16.1"
+    react: ">=18"
+    react-native: ">=0.72"
+  checksum: e90d6e202b98ad0757102ba8a8c4ea0998de130c29fc025f5a217826db7762cf8ba5ebf2b4c7a8875ea69363cbfde2c8e9c435f66c388278facb6ff3870eab48
+  languageName: node
+  linkType: hard
+
 "@reown/appkit-ethers-react-native@npm:latest":
   version: 2.0.1
   resolution: "@reown/appkit-ethers-react-native@npm:2.0.1"
@@ -5901,7 +5930,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@reown/appkit-react-native@npm:2.0.1, @reown/appkit-react-native@npm:latest":
+"@reown/appkit-react-native@npm:2.0.1":
   version: 2.0.1
   resolution: "@reown/appkit-react-native@npm:2.0.1"
   dependencies:
@@ -5921,6 +5950,26 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@reown/appkit-react-native@npm:^2.0.4":
+  version: 2.0.4
+  resolution: "@reown/appkit-react-native@npm:2.0.4"
+  dependencies:
+    "@reown/appkit-common-react-native": 2.0.4
+    "@reown/appkit-core-react-native": 2.0.4
+    "@reown/appkit-ui-react-native": 2.0.4
+    "@walletconnect/universal-provider": 2.21.10
+    valtio: 2.1.8
+  peerDependencies:
+    "@walletconnect/react-native-compat": ">=2.16.1"
+    "@walletconnect/utils": ">=2.16.1"
+    react: ">=18"
+    react-native: ">=0.72"
+    react-native-safe-area-context: ">=4.4.0"
+    react-native-svg: ">=13.10"
+  checksum: 44087f3d043a23ab698ce6493407f4482a7661760efeaa8d3d4d4b7416461d3cb297a6d2ba3b07c6b6ec44de936e827bfd1e087e604b60d5172e40dd011229b2
+  languageName: node
+  linkType: hard
+
 "@reown/appkit-ui-react-native@npm:2.0.1":
   version: 2.0.1
   resolution: "@reown/appkit-ui-react-native@npm:2.0.1"
@@ -5936,6 +5985,21 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@reown/appkit-ui-react-native@npm:2.0.4":
+  version: 2.0.4
+  resolution: "@reown/appkit-ui-react-native@npm:2.0.4"
+  dependencies:
+    "@reown/appkit-common-react-native": 2.0.4
+    polished: 4.3.1
+    qrcode: 1.5.3
+  peerDependencies:
+    react: ">=18"
+    react-native: ">=0.72"
+    react-native-svg: ">=13.10"
+  checksum: 85f164fda92fc5c6d41e4a33f2d3127af3e023f34540d50e0797a53f779ca9f9b6cfa2f3a90ce7f9ca55559e750e09871786c80bc84d8c65eac6c551f36af1bb
+  languageName: node
+  linkType: hard
+
 "@rneui/base@npm:^4.0.0-rc.8":
   version: 4.0.0-rc.8
   resolution: "@rneui/base@npm:4.0.0-rc.8"
@@ -12384,7 +12448,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"eventemitter3@npm:^4.0.0, eventemitter3@npm:^4.0.4":
+"eventemitter3@npm:^4.0.0, eventemitter3@npm:^4.0.4, eventemitter3@npm:^4.0.7":
   version: 4.0.7
   resolution: "eventemitter3@npm:4.0.7"
   checksum: 1875311c42fcfe9c707b2712c32664a245629b42bb0a5a84439762dd0fd637fc54d078155ea83c2af9e0323c9ac13687e03cfba79b03af9f40c89b4960099374
@@ -13117,7 +13181,7 @@ __metadata:
     "@react-navigation/native-stack": ^7.10.1
     "@react-navigation/stack": ^7.6.16
     "@reown/appkit-ethers-react-native": latest
-    "@reown/appkit-react-native": latest
+    "@reown/appkit-react-native": ^2.0.4
     "@rneui/base": ^4.0.0-rc.8
     "@rneui/themed": ^4.0.0-rc.8
     "@shopify/react-native-skia": ^2.4.14
@@ -13191,6 +13255,7 @@ __metadata:
     react-native-svg-transformer: ^1.5.2
     react-native-syntax-highlighter: ^2.1.0
     react-native-tab-view: ^4.2.2
+    react-native-tcp-socket: ^6.4.1
     react-native-url-polyfill: ^3.0.0
     react-native-vision-camera: ^4.6.3
     react-native-webview: ^13.16.0
@@ -19660,6 +19725,18 @@ __metadata:
   languageName: node
   linkType: hard
 
+"react-native-tcp-socket@npm:^6.4.1":
+  version: 6.4.1
+  resolution: "react-native-tcp-socket@npm:6.4.1"
+  dependencies:
+    buffer: ^5.4.3
+    eventemitter3: ^4.0.7
+  peerDependencies:
+    react-native: ">=0.60.0"
+  checksum: 0c0af3a3044a3edeb9fb5077476eba7ba26675b4af2a1d6b11a63cd56a939a63e4675a63cc1da72cd573cf37ae386a4e98b16b442e4adc11c0addbccaf48b925
+  languageName: node
+  linkType: hard
+
 "react-native-url-polyfill@npm:2.0.0":
   version: 2.0.0
   resolution: "react-native-url-polyfill@npm:2.0.0"