support serverless environments (#29)

* add --executable-path

* tests

* test vercel

* fixes

cli/src/commands.rs

@@ -886,6 +886,7 @@ mod tests {
             full: false,
             headed: false,
             debug: false,
+            executable_path: None,
         }
     }
 

cli/src/connection.rs

@@ -153,9 +153,15 @@ fn daemon_ready(session: &str) -> bool {
     }
 }
 
-pub fn ensure_daemon(session: &str, headed: bool) -> Result<(), String> {
+/// Result of ensure_daemon indicating whether a new daemon was started
+pub struct DaemonResult {
+    /// True if we connected to an existing daemon, false if we started a new one
+    pub already_running: bool,
+}
+
+pub fn ensure_daemon(session: &str, headed: bool, executable_path: Option<&str>) -> Result<DaemonResult, String> {
     if is_daemon_running(session) && daemon_ready(session) {
-        return Ok(());
+        return Ok(DaemonResult { already_running: true });
     }
 
     let exe_path = env::current_exe().map_err(|e| e.to_string())?;
@@ -186,6 +192,10 @@ pub fn ensure_daemon(session: &str, headed: bool) -> Result<(), String> {
             cmd.env("AGENT_BROWSER_HEADED", "1");
         }
 
+        if let Some(path) = executable_path {
+            cmd.env("AGENT_BROWSER_EXECUTABLE_PATH", path);
+        }
+
         // Create new process group and session to fully detach
         unsafe {
             cmd.pre_exec(|| {
@@ -220,6 +230,10 @@ pub fn ensure_daemon(session: &str, headed: bool) -> Result<(), String> {
             cmd.env("AGENT_BROWSER_HEADED", "1");
         }
 
+        if let Some(path) = executable_path {
+            cmd.env("AGENT_BROWSER_EXECUTABLE_PATH", path);
+        }
+
         // CREATE_NEW_PROCESS_GROUP | DETACHED_PROCESS
         const CREATE_NEW_PROCESS_GROUP: u32 = 0x00000200;
         const DETACHED_PROCESS: u32 = 0x00000008;
@@ -234,7 +248,7 @@ pub fn ensure_daemon(session: &str, headed: bool) -> Result<(), String> {
 
     for _ in 0..50 {
         if daemon_ready(session) {
-            return Ok(());
+            return Ok(DaemonResult { already_running: false });
         }
         thread::sleep(Duration::from_millis(100));
     }

cli/src/flags.rs

@@ -6,6 +6,7 @@ pub struct Flags {
     pub headed: bool,
     pub debug: bool,
     pub session: String,
+    pub executable_path: Option<String>,
 }
 
 pub fn parse_flags(args: &[String]) -> Flags {
@@ -15,6 +16,7 @@ pub fn parse_flags(args: &[String]) -> Flags {
         headed: false,
         debug: false,
         session: env::var("AGENT_BROWSER_SESSION").unwrap_or_else(|_| "default".to_string()),
+        executable_path: env::var("AGENT_BROWSER_EXECUTABLE_PATH").ok(),
     };
 
     let mut i = 0;
@@ -30,6 +32,12 @@ pub fn parse_flags(args: &[String]) -> Flags {
                     i += 1;
                 }
             }
+            "--executable-path" => {
+                if let Some(s) = args.get(i + 1) {
+                    flags.executable_path = Some(s.clone());
+                    i += 1;
+                }
+            }
             _ => {}
         }
         i += 1;
@@ -43,13 +51,15 @@ pub fn clean_args(args: &[String]) -> Vec<String> {
 
     // Global flags that should be stripped from command args
     const GLOBAL_FLAGS: &[&str] = &["--json", "--full", "--headed", "--debug"];
+    // Flags that take a value (skip both the flag and the next arg)
+    const VALUE_FLAGS: &[&str] = &["--session", "--executable-path"];
 
     for arg in args.iter() {
         if skip_next {
             skip_next = false;
             continue;
         }
-        if arg == "--session" {
+        if VALUE_FLAGS.contains(&arg.as_str()) {
             skip_next = true;
             continue;
         }
@@ -61,3 +71,43 @@ pub fn clean_args(args: &[String]) -> Vec<String> {
     }
     result
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn args(s: &str) -> Vec<String> {
+        s.split_whitespace().map(String::from).collect()
+    }
+
+    #[test]
+    fn test_parse_executable_path_flag() {
+        let flags = parse_flags(&args("--executable-path /path/to/chromium open example.com"));
+        assert_eq!(flags.executable_path, Some("/path/to/chromium".to_string()));
+    }
+
+    #[test]
+    fn test_parse_executable_path_flag_no_value() {
+        let flags = parse_flags(&args("--executable-path"));
+        assert_eq!(flags.executable_path, None);
+    }
+
+    #[test]
+    fn test_clean_args_removes_executable_path() {
+        let cleaned = clean_args(&args("--executable-path /path/to/chromium open example.com"));
+        assert_eq!(cleaned, vec!["open", "example.com"]);
+    }
+
+    #[test]
+    fn test_clean_args_removes_executable_path_with_other_flags() {
+        let cleaned = clean_args(&args("--json --executable-path /path/to/chromium --headed open example.com"));
+        assert_eq!(cleaned, vec!["open", "example.com"]);
+    }
+
+    #[test]
+    fn test_parse_flags_with_session_and_executable_path() {
+        let flags = parse_flags(&args("--session test --executable-path /custom/chrome open example.com"));
+        assert_eq!(flags.session, "test");
+        assert_eq!(flags.executable_path, Some("/custom/chrome".to_string()));
+    }
+}

cli/src/main.rs

@@ -149,13 +149,23 @@ fn main() {
         }
     };
 
-    if let Err(e) = ensure_daemon(&flags.session, flags.headed) {
-        if flags.json {
-            println!(r#"{{"success":false,"error":"{}"}}"#, e);
-        } else {
-            eprintln!("\x1b[31m✗\x1b[0m {}", e);
+    let daemon_result = match ensure_daemon(&flags.session, flags.headed, flags.executable_path.as_deref()) {
+        Ok(result) => result,
+        Err(e) => {
+            if flags.json {
+                println!(r#"{{"success":false,"error":"{}"}}"#, e);
+            } else {
+                eprintln!("\x1b[31m✗\x1b[0m {}", e);
+            }
+            exit(1);
+        }
+    };
+
+    // Warn if executable_path was specified but daemon was already running
+    if daemon_result.already_running && flags.executable_path.is_some() {
+        if !flags.json {
+            eprintln!("\x1b[33m⚠\x1b[0m --executable-path ignored: daemon already running. Use 'agent-browser close' first to restart with new path.");
         }
-        exit(1);
     }
 
     // If --headed flag is set, send launch command first to switch to headed mode

cli/src/output.rs

@@ -1186,6 +1186,7 @@ Snapshot Options:
 
 Options:
   --session <name>           Isolated session (or AGENT_BROWSER_SESSION env)
+  --executable-path <path>   Custom browser executable (or AGENT_BROWSER_EXECUTABLE_PATH)
   --json                     JSON output
   --full, -f                 Full page screenshot
   --headed                   Show browser window (not headless)