read external ips with fallback to standard notation 0.0.0.0

cli/commands/ui.py

@@ -15,7 +15,9 @@ def ui(
     from studio.backend.run import run_server
 
     if not silent:
-        typer.echo(f"Starting Unsloth UI on http://{host}:{port}")
+        from studio.backend.run import _resolve_external_ip
+        display_host = _resolve_external_ip() if host == "0.0.0.0" else host
+        typer.echo(f"Starting Unsloth Studio on http://{display_host}:{port}")
 
     run_server(
         host=host,

studio/backend/run.py

@@ -11,6 +11,51 @@ if str(backend_dir) not in sys.path:
     sys.path.insert(0, str(backend_dir))
 
 
+def _resolve_external_ip() -> str:
+    """
+    Resolve the machine's external IP address.
+
+    Tries (in order):
+    1. GCE metadata server (instant, works on Google Cloud VMs)
+    2. ifconfig.me (works anywhere with internet)
+    3. LAN IP via UDP socket trick (fallback)
+    """
+    import urllib.request
+    import socket
+
+    # 1. Try GCE metadata server (responds in <10ms on GCE, times out fast elsewhere)
+    try:
+        req = urllib.request.Request(
+            "http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/access-configs/0/external-ip",
+            headers={"Metadata-Flavor": "Google"},
+        )
+        with urllib.request.urlopen(req, timeout=1) as resp:
+            ip = resp.read().decode().strip()
+            if ip:
+                return ip
+    except Exception:
+        pass
+
+    # 2. Try public IP service
+    try:
+        with urllib.request.urlopen("https://ifconfig.me", timeout=3) as resp:
+            ip = resp.read().decode().strip()
+            if ip:
+                return ip
+    except Exception:
+        pass
+
+    # 3. Fallback: LAN IP via UDP socket trick
+    try:
+        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        s.connect(("8.8.8.8", 80))
+        ip = s.getsockname()[0]
+        s.close()
+        return ip
+    except Exception:
+        return "0.0.0.0"
+
+
 def run_server(
     host: str = "0.0.0.0",
     port: int = 8000,
@@ -57,26 +102,15 @@ def run_server(
     time.sleep(3)
 
     if not silent:
-        # Resolve actual IP when binding to 0.0.0.0
-        display_host = host
-        if host == "0.0.0.0":
-            import socket
-            try:
-                # UDP connect trick — gets the machine's outbound IP without sending data
-                s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-                s.connect(("8.8.8.8", 80))
-                display_host = s.getsockname()[0]
-                s.close()
-            except Exception:
-                display_host = "localhost"
+        display_host = _resolve_external_ip() if host == "0.0.0.0" else host
 
         print("")
         print("=" * 50)
         print(f"🦥 Unsloth Studio is running on port {port}")
-        print(f"   Local:   http://localhost:{port}")
+        print(f"   Local:    http://localhost:{port}")
         print(f"   External: http://{display_host}:{port}")
-        print(f"   API:     http://{display_host}:{port}/api")
-        print(f"   Health:  http://{display_host}:{port}/api/health")
+        print(f"   API:      http://{display_host}:{port}/api")
+        print(f"   Health:   http://{display_host}:{port}/api/health")
         print("=" * 50)
 
     return app