diff --git a/src/main.rs b/src/main.rs
index 7b52d29..363fc9c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -115,9 +115,9 @@ fn main() {
             }
         }
         Some("watch") => {
-            let dir = env::args().nth(2).unwrap_or_else(|| ".".to_string());
-            let config = parse_flag("-f");
-            if let Err(e) = aishell::watch::run(&dir, config.as_deref()) {
+            let dir = env::args().nth(2).unwrap_or_else(|| "src/".to_string());
+            let preset = parse_flag("-p");
+            if let Err(e) = aishell::watch::run(&dir, preset.as_deref()) {
                 eprintln!("aishell: {}", e);
                 std::process::exit(1);
             }
@@ -158,7 +158,7 @@ fn print_help() {
     println!("  aishell history [id]        Show past sessions");
     println!("  aishell history cmd [grep]  Command history (filterable)");
     println!("  aishell history clean       Remove old sessions (keep 10)");
-    println!("  aishell watch <dir> [-f cfg] Watch files, auto-trigger loop");
+    println!("  aishell watch [dir] [-p preset] Watch files → run preset on change");
     println!("  aishell next                Resume loop");
     println!("  aishell stop                Stop the loop");
     println!("  aishell help                This help");
diff --git a/src/watch.rs b/src/watch.rs
index e7fcc2a..641f671 100644
--- a/src/watch.rs
+++ b/src/watch.rs
@@ -3,65 +3,59 @@ use std::sync::mpsc;
 use std::time::{Duration, Instant};
 use notify::{Watcher, RecursiveMode, Event, EventKind};
 
-const STATE_DIR: &str = "/tmp/aishell";
 const DEBOUNCE_MS: u64 = 2000;
 
-/// Watch a directory for file changes.
-/// On change, write next=true to loop.json with changed file list.
-pub fn run(dir: &str, config: Option<&str>) -> Result<(), String> {
+/// Watch directory, run preset on change.
+/// `aishell watch src/ -p review` → file change → review → auto-commit
+pub fn run(dir: &str, preset: Option<&str>) -> Result<(), String> {
     let dir = crate::config::expand_tilde(dir);
     let dir_path = Path::new(&dir);
     if !dir_path.is_dir() {
         return Err(format!("not a directory: {dir}"));
     }
 
-    // Start headless run in background if config provided
-    if let Some(cfg) = config {
-        let cfg = cfg.to_string();
-        std::thread::spawn(move || {
-            let _ = crate::headless::run(&cfg, None, None);
-        });
-        // Give it time to start
-        std::thread::sleep(Duration::from_secs(2));
-    }
-
-    eprintln!("watching: {dir}");
+    let preset = preset.unwrap_or("review");
+    eprintln!("watching: {dir} (preset: {preset})");
     eprintln!("Ctrl+C to stop.\n");
 
     let (tx, rx) = mpsc::channel::<Event>();
 
     let mut watcher = notify::recommended_watcher(move |res: Result<Event, notify::Error>| {
-        if let Ok(event) = res {
-            let _ = tx.send(event);
-        }
+        if let Ok(event) = res { let _ = tx.send(event); }
     }).map_err(|e| format!("watcher error: {e}"))?;
 
     watcher.watch(dir_path, RecursiveMode::Recursive)
         .map_err(|e| format!("watch error: {e}"))?;
 
     let mut last_trigger = Instant::now();
-    let mut changed_files: Vec<String> = Vec::new();
+    let mut changed: Vec<String> = Vec::new();
 
     loop {
         match rx.recv_timeout(Duration::from_millis(500)) {
             Ok(event) => {
                 if !is_relevant(&event) { continue; }
-
-                for path in &event.paths {
-                    let p = path.display().to_string();
-                    if !changed_files.contains(&p) {
-                        changed_files.push(p);
-                    }
+                for p in &event.paths {
+                    let s = p.display().to_string();
+                    if !changed.contains(&s) { changed.push(s); }
                 }
                 last_trigger = Instant::now();
             }
             Err(mpsc::RecvTimeoutError::Timeout) => {
-                // Debounce: if we have changes and enough time passed
-                if !changed_files.is_empty()
-                    && last_trigger.elapsed() > Duration::from_millis(DEBOUNCE_MS)
-                {
-                    trigger_cycle(&changed_files);
-                    changed_files.clear();
+                if !changed.is_empty() && last_trigger.elapsed() > Duration::from_millis(DEBOUNCE_MS) {
+                    let short: Vec<&str> = changed.iter()
+                        .map(|f| f.rsplit('/').next().unwrap_or(f))
+                        .take(5).collect();
+                    eprintln!("  changed: {}", short.join(", "));
+
+                    // Run preset
+                    if preset == "review" {
+                        crate::headless::review();
+                    } else {
+                        let _ = crate::headless::run_preset(preset);
+                    }
+
+                    changed.clear();
+                    eprintln!("\n  watching...");
                 }
             }
             Err(_) => break,
@@ -76,35 +70,6 @@ fn is_relevant(event: &Event) -> bool {
         EventKind::Create(_) | EventKind::Modify(_) | EventKind::Remove(_)
     ) && event.paths.iter().any(|p| {
         let s = p.display().to_string();
-        // Ignore hidden files, target/, /tmp/
         !s.contains("/.") && !s.contains("/target/") && !s.contains("/tmp/")
     })
 }
-
-fn trigger_cycle(files: &[String]) {
-    let short: Vec<&str> = files.iter()
-        .map(|f| f.rsplit('/').next().unwrap_or(f))
-        .take(5)
-        .collect();
-
-    eprintln!("  changed: {}", short.join(", "));
-
-    // Write to loop.json to signal the running headless loop
-    let loop_path = format!("{STATE_DIR}/loop.json");
-    if Path::new(&loop_path).exists() {
-        let control = serde_json::json!({
-            "ready": true,
-            "next": true,
-            "quit": false,
-            "changed_files": files,
-        });
-        let json = serde_json::to_string_pretty(&control).unwrap_or_default();
-        // atomic write
-        let tmp = format!("{loop_path}.tmp");
-        if std::fs::write(&tmp, &json).is_ok() {
-            let _ = std::fs::rename(&tmp, &loop_path);
-        }
-    } else {
-        eprintln!("  (no active loop to signal)");
-    }
-}