Auto-install protocol handler when exe run without args

agent/src/install.rs

@@ -301,6 +301,51 @@ pub fn install(force_user_install: bool) -> Result<()> {
     Ok(())
 }
 
+/// Check if the guruconnect:// protocol handler is registered
+#[cfg(windows)]
+pub fn is_protocol_handler_registered() -> bool {
+    use windows::Win32::System::Registry::{
+        RegOpenKeyExW, RegCloseKey, HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, KEY_READ,
+    };
+
+    unsafe {
+        // Check system-wide registration (HKCR\guruconnect)
+        let mut key = HKEY::default();
+        let key_path = to_wide("guruconnect");
+        if RegOpenKeyExW(
+            HKEY_CLASSES_ROOT,
+            PCWSTR(key_path.as_ptr()),
+            0,
+            KEY_READ,
+            &mut key,
+        ).is_ok() {
+            let _ = RegCloseKey(key);
+            return true;
+        }
+
+        // Check user-level registration (HKCU\Software\Classes\guruconnect)
+        let key_path = to_wide(r"Software\Classes\guruconnect");
+        if RegOpenKeyExW(
+            HKEY_CURRENT_USER,
+            PCWSTR(key_path.as_ptr()),
+            0,
+            KEY_READ,
+            &mut key,
+        ).is_ok() {
+            let _ = RegCloseKey(key);
+            return true;
+        }
+    }
+
+    false
+}
+
+#[cfg(not(windows))]
+pub fn is_protocol_handler_registered() -> bool {
+    // On non-Windows, assume not registered (or check ~/.local/share/applications)
+    false
+}
+
 /// Parse a guruconnect:// URL and extract session parameters
 pub fn parse_protocol_url(url: &str) -> Result<(String, String, Option<String>)> {
     // Expected formats:

agent/src/main.rs

@@ -138,13 +138,19 @@ fn main() -> Result<()> {
             if let Some(code) = cli.support_code {
                 run_agent_mode(Some(code))
             } else {
-                // No args: check if we should auto-detect mode
+                // No args: check if protocol handler is installed
-                // For now, default to agent mode
+                // If not, run install mode (user likely downloaded from web)
+                if !install::is_protocol_handler_registered() {
+                    info!("Protocol handler not registered, running installer");
+                    run_install(false)
+                } else {
+                    // Protocol handler exists, run as agent
                     run_agent_mode(None)
                 }
             }
         }
     }
+}
 
 /// Run in agent mode (receive remote connections)
 fn run_agent_mode(support_code: Option<String>) -> Result<()> {