feat: add --auto-connect flag to discover and connect to running Chrome (#432)

cli/src/commands.rs

@@ -1429,6 +1429,7 @@ mod tests {
             ignore_https_errors: false,
             allow_file_access: false,
             device: None,
+            auto_connect: false,
             cli_executable_path: false,
             cli_extensions: false,
             cli_profile: false,

cli/src/flags.rs

@@ -20,6 +20,7 @@ pub struct Flags {
     pub ignore_https_errors: bool,
     pub allow_file_access: bool,
     pub device: Option<String>,
+    pub auto_connect: bool,
 
     // Track which launch-time options were explicitly passed via CLI
     // (as opposed to being set only via environment variables)
@@ -65,6 +66,7 @@ pub fn parse_flags(args: &[String]) -> Flags {
         ignore_https_errors: false,
         allow_file_access: env::var("AGENT_BROWSER_ALLOW_FILE_ACCESS").is_ok(),
         device: env::var("AGENT_BROWSER_IOS_DEVICE").ok(),
+        auto_connect: env::var("AGENT_BROWSER_AUTO_CONNECT").is_ok(),
         // Track CLI-passed flags (default false, set to true when flag is passed)
         cli_executable_path: false,
         cli_extensions: false,
@@ -175,6 +177,7 @@ pub fn parse_flags(args: &[String]) -> Flags {
                     i += 1;
                 }
             }
+            "--auto-connect" => flags.auto_connect = true,
             _ => {}
         }
         i += 1;
@@ -194,6 +197,7 @@ pub fn clean_args(args: &[String]) -> Vec<String> {
         "--debug",
         "--ignore-https-errors",
         "--allow-file-access",
+        "--auto-connect",
     ];
     // Global flags that take a value (need to skip the next arg too)
     const GLOBAL_FLAGS_WITH_VALUE: &[&str] = &[

cli/src/main.rs

@@ -289,7 +289,27 @@ fn main() {
         if flags.json {
             println!(r#"{{"success":false,"error":"{}"}}"#, msg);
         } else {
-            eprintln!("\x1b[31m✗\x1b[0m {}", msg);
+            eprintln!("{} {}", color::error_indicator(), msg);
+        }
+        exit(1);
+    }
+
+    if flags.auto_connect && flags.cdp.is_some() {
+        let msg = "Cannot use --auto-connect and --cdp together";
+        if flags.json {
+            println!(r#"{{"success":false,"error":"{}"}}"#, msg);
+        } else {
+            eprintln!("{} {}", color::error_indicator(), msg);
+        }
+        exit(1);
+    }
+
+    if flags.auto_connect && flags.provider.is_some() {
+        let msg = "Cannot use --auto-connect and -p/--provider together";
+        if flags.json {
+            println!(r#"{{"success":false,"error":"{}"}}"#, msg);
+        } else {
+            eprintln!("{} {}", color::error_indicator(), msg);
         }
         exit(1);
     }
@@ -299,11 +319,42 @@ fn main() {
         if flags.json {
             println!(r#"{{"success":false,"error":"{}"}}"#, msg);
         } else {
-            eprintln!("\x1b[31m✗\x1b[0m {}", msg);
+            eprintln!("{} {}", color::error_indicator(), msg);
         }
         exit(1);
     }
 
+    // Auto-connect to existing browser
+    if flags.auto_connect {
+        let mut launch_cmd = json!({
+            "id": gen_id(),
+            "action": "launch",
+            "autoConnect": true
+        });
+
+        if flags.ignore_https_errors {
+            launch_cmd["ignoreHTTPSErrors"] = json!(true);
+        }
+
+        let err = match send_command(launch_cmd, &flags.session) {
+            Ok(resp) if resp.success => None,
+            Ok(resp) => Some(
+                resp.error
+                    .unwrap_or_else(|| "Auto-connect failed".to_string()),
+            ),
+            Err(e) => Some(e.to_string()),
+        };
+
+        if let Some(msg) = err {
+            if flags.json {
+                println!(r#"{{"success":false,"error":"{}"}}"#, msg);
+            } else {
+                eprintln!("{} {}", color::error_indicator(), msg);
+            }
+            exit(1);
+        }
+    }
+
     // Connect via CDP if --cdp flag is set
     // Accepts either a port number (e.g., "9222") or a full URL (e.g., "ws://..." or "wss://...")
     if let Some(ref cdp_value) = flags.cdp {

cli/src/output.rs

@@ -1778,6 +1778,7 @@ Options:
   --full, -f                 Full page screenshot
   --headed                   Show browser window (not headless)
   --cdp <port>               Connect via CDP (Chrome DevTools Protocol)
+  --auto-connect             Auto-discover and connect to running Chrome
   --debug                    Debug output
   --version, -V              Show version
 
@@ -1785,6 +1786,7 @@ Environment:
   AGENT_BROWSER_SESSION          Session name (default: "default")
   AGENT_BROWSER_EXECUTABLE_PATH  Custom browser executable path
   AGENT_BROWSER_PROVIDER         Browser provider (ios, browserbase, kernel, browseruse)
+  AGENT_BROWSER_AUTO_CONNECT     Auto-discover and connect to running Chrome
   AGENT_BROWSER_STREAM_PORT      Enable WebSocket streaming on port (e.g., 9223)
   AGENT_BROWSER_IOS_DEVICE       Default iOS device name
   AGENT_BROWSER_IOS_UDID         Default iOS device UDID
@@ -1798,6 +1800,7 @@ Examples:
   agent-browser get text @e1
   agent-browser screenshot --full
   agent-browser --cdp 9222 snapshot      # Connect via CDP port
+  agent-browser --auto-connect snapshot  # Auto-discover running Chrome
   agent-browser --profile ~/.myapp open example.com  # Persistent profile
 
 iOS Simulator (requires Xcode and Appium):