diff --git a/engine/integration_test b/engine/integration_test
index 054738c..0827ef1 100755
Binary files a/engine/integration_test and b/engine/integration_test differ
diff --git a/engine/looper b/engine/looper
index 1c6835c..fcdef18 100755
Binary files a/engine/looper and b/engine/looper differ
diff --git a/engine/src/channel.c b/engine/src/channel.c
index f6ffef0..64d0648 100644
--- a/engine/src/channel.c
+++ b/engine/src/channel.c
@@ -17,7 +17,8 @@ void channel_add(jack_client_t *client, int idx) {
   snprintf(in_name, sizeof(in_name), "channel%d_input", next_channel_id);
   snprintf(out_name, sizeof(out_name), "channel%d_output", next_channel_id);
 
-  /* Always register audio ports (needed for pass-through even for MIDI channels?) */
+  /* Always register audio ports (needed for pass-through even for MIDI
+   * channels?) */
   channels[idx].audio_in = jack_port_register(
       client, in_name, JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
   channels[idx].audio_out = jack_port_register(
@@ -32,24 +33,26 @@ void channel_add(jack_client_t *client, int idx) {
 
   /* If this is a MIDI channel, register MIDI ports */
   if (channels[idx].type == CHANNEL_MIDI) {
-      char midi_in_name[64], midi_out_name[64];
-      snprintf(midi_in_name, sizeof(midi_in_name), "channel%d_midi_in", next_channel_id);
-      snprintf(midi_out_name, sizeof(midi_out_name), "channel%d_midi_out", next_channel_id);
-      channels[idx].midi_in = jack_port_register(
-          client, midi_in_name, JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
-      channels[idx].midi_out = jack_port_register(
-          client, midi_out_name, JACK_DEFAULT_MIDI_TYPE, JackPortIsOutput, 0);
-      if (!channels[idx].midi_in || !channels[idx].midi_out) {
-          fprintf(stderr, "Failed to register MIDI ports for channel %d\n",
-                  next_channel_id);
-          atomic_store(&channels[idx].active, 0);
-          jack_port_unregister(client, channels[idx].audio_in);
-          jack_port_unregister(client, channels[idx].audio_out);
-          return;
-      }
+    char midi_in_name[64], midi_out_name[64];
+    snprintf(midi_in_name, sizeof(midi_in_name), "channel%d_midi_in",
+             next_channel_id);
+    snprintf(midi_out_name, sizeof(midi_out_name), "channel%d_midi_out",
+             next_channel_id);
+    channels[idx].midi_in = jack_port_register(
+        client, midi_in_name, JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
+    channels[idx].midi_out = jack_port_register(
+        client, midi_out_name, JACK_DEFAULT_MIDI_TYPE, JackPortIsOutput, 0);
+    if (!channels[idx].midi_in || !channels[idx].midi_out) {
+      fprintf(stderr, "Failed to register MIDI ports for channel %d\n",
+              next_channel_id);
+      atomic_store(&channels[idx].active, 0);
+      jack_port_unregister(client, channels[idx].audio_in);
+      jack_port_unregister(client, channels[idx].audio_out);
+      return;
+    }
   } else {
-      channels[idx].midi_in = NULL;
-      channels[idx].midi_out = NULL;
+    channels[idx].midi_in = NULL;
+    channels[idx].midi_out = NULL;
   }
 
   atomic_store(&channels[idx].active, 1);
diff --git a/engine/src/channel.c~ b/engine/src/channel.c~
deleted file mode 100644
index a004c21..0000000
--- a/engine/src/channel.c~
+++ /dev/null
@@ -1,117 +0,0 @@
-// cppcheck-suppress missingIncludeSystem
-#include "channel.h"
-#include <jack/jack.h>
-#include <stdatomic.h>
-#include <stdio.h>
-#include <string.h>
-
-<<<<<<< HEAD
-=======
-/* Helper: zero a scene and set its state to IDLE */
-static void init_scene(scene_t *sc) {
-  memset(sc, 0, sizeof(scene_t));
-  atomic_store(&sc->state, STATE_IDLE);
-  atomic_store(&sc->prev_state, -1);
-}
-
->>>>>>> 3-integrate-carla
-void channel_add(jack_client_t *client, int idx) {
-  char in_name[64], out_name[64];
-  snprintf(in_name, sizeof(in_name), "channel%d_input", next_channel_id);
-  snprintf(out_name, sizeof(out_name), "channel%d_output", next_channel_id);
-
-  channels[idx].audio_in = jack_port_register(
-      client, in_name, JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
-  channels[idx].audio_out = jack_port_register(
-      client, out_name, JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
-  if (!channels[idx].audio_in || !channels[idx].audio_out) {
-    fprintf(stderr, "Failed to register ports for channel %d\n",
-            next_channel_id);
-    /* Do NOT mark channel active – process loop will skip it */
-    atomic_store(&channels[idx].active, 0);
-    return;
-  }
-
-  atomic_store(&channels[idx].active, 1);
-  atomic_store(&channels[idx].state, STATE_IDLE);
-  channels[idx].prev_state = -1;
-  channels[idx].loop_count = 0;
-  channels[idx].record_pos = 0;
-  channels[idx].playback_pos = 0;
-  channels[idx].save_ring = NULL;
-
-  next_channel_id++;
-  channel_count++;
-}
-
-void channel_remove(jack_client_t *client, int idx) {
-  (void)client;
-<<<<<<< HEAD
-  atomic_store(&channels[idx].active, 0);
-  channel_count--;
-=======
-  struct channel_t *cur = get_channels_array();
-  atomic_store(&cur[idx].active, 0);
-  atomic_fetch_sub(&channel_count, 1);
-}
-
-void channel_add_scene(jack_client_t *client, int idx) {
-  (void)client;
-  struct channel_t *cur = get_channels_array();
-  if (atomic_load(&cur[idx].scene_count) >= MAX_SCENES)
-    return;
-  int ns = atomic_load(&cur[idx].scene_count);
-  init_scene(&cur[idx].scenes[ns]);
-  atomic_fetch_add(&cur[idx].scene_count, 1);
-}
-
-void channel_remove_scene(jack_client_t *client, int idx) {
-  (void)client;
-  struct channel_t *cur = get_channels_array();
-  int sc = atomic_load(&cur[idx].scene_count);
-  if (sc <= 1)
-    return;
-  int cs = atomic_load(&cur[idx].current_scene);
-  /* shift remaining scenes down (atomic copy of fields) */
-  for (int i = cs; i < sc - 1; i++) {
-    atomic_store(&cur[idx].scenes[i].loop_count,
-                 atomic_load(&cur[idx].scenes[i + 1].loop_count));
-    atomic_store(&cur[idx].scenes[i].record_pos,
-                 atomic_load(&cur[idx].scenes[i + 1].record_pos));
-    atomic_store(&cur[idx].scenes[i].playback_pos,
-                 atomic_load(&cur[idx].scenes[i + 1].playback_pos));
-    atomic_store(&cur[idx].scenes[i].state,
-                 atomic_load(&cur[idx].scenes[i + 1].state));
-    atomic_store(&cur[idx].scenes[i].prev_state,
-                 atomic_load(&cur[idx].scenes[i + 1].prev_state));
-    /* copy loop data (may race with RT thread; acceptable for this release) */
-    memcpy(cur[idx].scenes[i].loop.audio_buffer,
-           cur[idx].scenes[i + 1].loop.audio_buffer,
-           LOOP_BUF_SIZE * sizeof(float));
-  }
-  atomic_fetch_sub(&cur[idx].scene_count, 1);
-  int new_sc = atomic_load(&cur[idx].scene_count);
-  if (cs >= new_sc)
-    atomic_store(&cur[idx].current_scene, new_sc - 1);
-}
-
-void channel_next_scene(jack_client_t *client, int idx) {
-  (void)client;
-  struct channel_t *cur = get_channels_array();
-  int sc = atomic_load(&cur[idx].scene_count);
-  if (sc > 1) {
-    int cs = atomic_load(&cur[idx].current_scene);
-    atomic_store(&cur[idx].current_scene, (cs + 1) % sc);
-  }
-}
-
-void channel_prev_scene(jack_client_t *client, int idx) {
-  (void)client;
-  struct channel_t *cur = get_channels_array();
-  int sc = atomic_load(&cur[idx].scene_count);
-  if (sc > 1) {
-    int cs = atomic_load(&cur[idx].current_scene);
-    atomic_store(&cur[idx].current_scene, (cs - 1 + sc) % sc);
-  }
->>>>>>> 3-integrate-carla
-}
diff --git a/engine/src/channel.o b/engine/src/channel.o
index b39bc85..7c32a58 100644
Binary files a/engine/src/channel.o and b/engine/src/channel.o differ
diff --git a/engine/src/looper.c b/engine/src/looper.c
index 62224cb..62a9fec 100644
--- a/engine/src/looper.c
+++ b/engine/src/looper.c
@@ -2,9 +2,9 @@
 #include "looper.h"
 #include "channel.h"
 #include "midi.h"
+#include "pipe.h"
 #include "queue.h"
 #include "wav.h"
-#include "pipe.h"
 #include <fcntl.h>
 #include <jack/jack.h>
 #include <jack/midiport.h>
@@ -38,13 +38,23 @@ static void looper_write_status(void) {
     int state = atomic_load(&channels[ch].scenes[sc_idx].state);
     const char *state_str;
     switch (state) {
-    case STATE_IDLE:   state_str = "IDLE";   break;
-    case STATE_RECORD: state_str = "RECORD"; break;
-    case STATE_LOOPING:state_str = "LOOPING";break;
-    case STATE_PAUSED: state_str = "PAUSED"; break;
-    default:           state_str = "UNKNOWN";
+    case STATE_IDLE:
+      state_str = "IDLE";
+      break;
+    case STATE_RECORD:
+      state_str = "RECORD";
+      break;
+    case STATE_LOOPING:
+      state_str = "LOOPING";
+      break;
+    case STATE_PAUSED:
+      state_str = "PAUSED";
+      break;
+    default:
+      state_str = "UNKNOWN";
     }
-    int n = snprintf(buf, sizeof(buf), "CH=%d SC=%d STATE=%s\n", ch, sc_idx, state_str);
+    int n = snprintf(buf, sizeof(buf), "CH=%d SC=%d STATE=%s\n", ch, sc_idx,
+                     state_str);
     if (n > 0) {
       int ret = write(status_fd, buf, n);
       (void)ret;
@@ -69,101 +79,101 @@ atomic_int bind_channel = 0;
 /* Deferred removal index (1 second grace) */
 static int pending_unregister_idx = -1;
 
-/* writer thread function and sample rate holder */
-static void *writer_thread(void *arg);
+/* sample rate holder */
 static int global_sample_rate = 0;
 
 /* execute a single command (called from looper_process_commands) */
 static void exec_command(command_t cmd, jack_client_t *client) {
-    int ch = cmd.channel;
-    if (ch < 0) ch = 0;
+  int ch = cmd.channel;
+  if (ch < 0)
+    ch = 0;
 
-    switch (cmd.type) {
-    case CMD_CYCLE: {
-      int sc_idx = atomic_load(&channels[ch].current_scene);
-      int state = atomic_load(&channels[ch].scenes[sc_idx].state);
-      switch (state) {
-      case STATE_IDLE:
-        atomic_store(&channels[ch].scenes[sc_idx].state, STATE_RECORD);
-        break;
-      case STATE_RECORD:
-        atomic_store(&channels[ch].scenes[sc_idx].state, STATE_LOOPING);
-        break;
-      case STATE_LOOPING:
-        atomic_store(&channels[ch].scenes[sc_idx].state, STATE_PAUSED);
-        break;
-      case STATE_PAUSED:
-        atomic_store(&channels[ch].scenes[sc_idx].state, STATE_LOOPING);
-        break;
-      }
-      atomic_store(&channels[ch].scenes[sc_idx].prev_state, -1);
+  switch (cmd.type) {
+  case CMD_CYCLE: {
+    int sc_idx = atomic_load(&channels[ch].current_scene);
+    scene_t *sc_ptr = &channels[ch].scenes[sc_idx];
+    int state = atomic_load(&sc_ptr->state);
+    switch (state) {
+    case STATE_IDLE:
+      atomic_store(&sc_ptr->state, STATE_RECORD);
+      break;
+    case STATE_RECORD:
+      atomic_store(&sc_ptr->state, STATE_LOOPING);
+      break;
+    case STATE_LOOPING:
+      atomic_store(&sc_ptr->state, STATE_PAUSED);
+      break;
+    case STATE_PAUSED:
+      atomic_store(&sc_ptr->state, STATE_LOOPING);
       break;
     }
-    case CMD_STOP:
-      for (int s = 0; s < atomic_load(&channels[ch].scene_count); s++) {
-        atomic_store(&channels[ch].scenes[s].state, STATE_IDLE);
-        atomic_store(&channels[ch].scenes[s].prev_state, -1);
-      }
-      break;
-
-    case CMD_ADD_CHANNEL:
-    case CMD_ADD_MIDI_CHANNEL: {
-      int idx;
-      for (idx = 0; idx < MAX_CHANNELS; idx++)
-        if (!channels[idx].active)
-          break;
-      if (idx < MAX_CHANNELS)
-        channel_add(client, idx);
-      break;
+    break;
+  }
+  case CMD_STOP:
+    for (int s = 0; s < atomic_load(&channels[ch].scene_count); s++) {
+      atomic_store(&channels[ch].scenes[s].state, STATE_IDLE);
+      atomic_store(&channels[ch].scenes[s].prev_state, -1);
     }
+    break;
 
-    case CMD_REMOVE_CHANNEL: {
-      int remove_idx = -1;
-      for (int idx = 1; idx < MAX_CHANNELS; idx++)
-        if (channels[idx].active)
-          remove_idx = idx;
-      if (remove_idx != -1) {
-        channel_remove(client, remove_idx);
-        pending_unregister_idx = remove_idx;
-      }
-      break;
+  case CMD_ADD_CHANNEL:
+  case CMD_ADD_MIDI_CHANNEL: {
+    int idx;
+    for (idx = 0; idx < MAX_CHANNELS; idx++)
+      if (!channels[idx].active)
+        break;
+    if (idx < MAX_CHANNELS)
+      channel_add(client, idx);
+    break;
+  }
+
+  case CMD_REMOVE_CHANNEL: {
+    int remove_idx = -1;
+    for (int idx = 1; idx < MAX_CHANNELS; idx++)
+      if (channels[idx].active)
+        remove_idx = idx;
+    if (remove_idx != -1) {
+      channel_remove(client, remove_idx);
+      pending_unregister_idx = remove_idx;
     }
+    break;
+  }
 
-    case CMD_BIND_CHANNEL:
-      atomic_store(&bind_channel, cmd.data);
-      break;
+  case CMD_BIND_CHANNEL:
+    atomic_store(&bind_channel, cmd.data);
+    break;
 
-    case CMD_UNBIND:
-      atomic_store(&bind_channel, 0);
-      break;
+  case CMD_UNBIND:
+    atomic_store(&bind_channel, 0);
+    break;
 
-    case CMD_LOAD:
-      atomic_store(&cmd_load, 1);
-      break;
+  case CMD_LOAD:
+    atomic_store(&cmd_load, 1);
+    break;
 
-    case CMD_SAVE:
-      atomic_store(&cmd_save, 1);
-      break;
+  case CMD_SAVE:
+    atomic_store(&cmd_save, 1);
+    break;
 
-    case CMD_ADD_SCENE:
-      channel_add_scene(client, ch);
-      break;
+  case CMD_ADD_SCENE:
+    channel_add_scene(client, ch);
+    break;
 
-    case CMD_REMOVE_SCENE:
-      channel_remove_scene(client, ch);
-      break;
+  case CMD_REMOVE_SCENE:
+    channel_remove_scene(client, ch);
+    break;
 
-    case CMD_NEXT_SCENE:
-      channel_next_scene(client, ch);
-      break;
+  case CMD_NEXT_SCENE:
+    channel_next_scene(client, ch);
+    break;
 
-    case CMD_PREV_SCENE:
-      channel_prev_scene(client, ch);
-      break;
+  case CMD_PREV_SCENE:
+    channel_prev_scene(client, ch);
+    break;
 
-    default:
-      break;
-    }
+  default:
+    break;
+  }
 }
 
 /* ----------------------------------------------------------------
@@ -217,7 +227,8 @@ int process_callback(jack_nframes_t nframes, void *arg) {
       /* MIDI channel handling */
       void *midi_in_buf = jack_port_get_buffer(channels[c].midi_in, nframes);
       void *midi_out_buf = jack_port_get_buffer(channels[c].midi_out, nframes);
-      if (!midi_out_buf) continue;
+      if (!midi_out_buf)
+        continue;
 
       switch (state) {
       case STATE_RECORD: {
@@ -232,7 +243,8 @@ int process_callback(jack_nframes_t nframes, void *arg) {
               sc->loop.midi_events[rp].timestamp = ev.time;
               sc->loop.midi_events[rp].status = ev.buffer[0];
               sc->loop.midi_events[rp].note = (ev.size > 1) ? ev.buffer[1] : 0;
-              sc->loop.midi_events[rp].velocity = (ev.size > 2) ? ev.buffer[2] : 0;
+              sc->loop.midi_events[rp].velocity =
+                  (ev.size > 2) ? ev.buffer[2] : 0;
               atomic_store(&sc->record_pos, rp + 1);
             }
           }
@@ -286,7 +298,8 @@ int process_callback(jack_nframes_t nframes, void *arg) {
     jack_default_audio_sample_t *out =
         (jack_default_audio_sample_t *)jack_port_get_buffer(
             channels[c].audio_out, nframes);
-    if (!out) continue;
+    if (!out)
+      continue;
 
     switch (state) {
     case STATE_RECORD:
@@ -397,7 +410,6 @@ void jack_shutdown_cb(void *arg) {
   exit(0);
 }
 
-
 /* ----------------------------------------------------------------
  * looper initialisation
  * ---------------------------------------------------------------- */
@@ -408,10 +420,11 @@ int looper_init(jack_client_t *client) {
   /* create status FIFO (ignore if already exists) */
   mkfifo(STATUS_FIFO, 0666);
 
-  /* open the status FIFO for reading+writing so writes work even without reader */
+  /* open the status FIFO for reading+writing so writes work even without reader
+   */
   status_fd = open(STATUS_FIFO, O_RDWR);
   if (status_fd < 0) {
-      perror("open status FIFO");
+    perror("open status FIFO");
   }
 
   queue_init(&cmd_queue);
@@ -421,10 +434,9 @@ int looper_init(jack_client_t *client) {
   /* start the FIFO reader thread */
   pipe_start_reader();
 
-
   /* channel 0 */
   channels[0].active = 1;
-  channels[0].type = CHANNEL_AUDIO;  /* default */
+  channels[0].type = CHANNEL_AUDIO; /* default */
   channels[0].current_scene = 0;
   channels[0].scene_count = 1;
   init_scene(&channels[0].scenes[0]); /* sets state IDLE, prev_state -1 */
@@ -453,58 +465,15 @@ int looper_init(jack_client_t *client) {
     return -1;
   }
 
+  /* Give JACK time to register the ports before clients connect */
+  {
+    struct timespec req = {.tv_sec = 0, .tv_nsec = 500000000};
+    nanosleep(&req, NULL);
+  }
+
   return 0;
 }
 
-/* ----------------------------------------------------------------
- * writer thread – consumes the save ring and writes WAV file
- * ---------------------------------------------------------------- */
-static void *writer_thread(void *arg) {
-  struct channel_t *ch = (struct channel_t *)arg;
-  int sc_idx = atomic_load(&ch->current_scene);
-  scene_t *sc = &ch->scenes[sc_idx];
-  RingBuf *ring = (RingBuf *)ch->save_ring;
-  if (!ring)
-    return NULL;
-
-  static const char *path = "save.wav";
-  unsigned sr = (unsigned)global_sample_rate;
-  if (sr == 0)
-    sr = 48000;
-
-  int lc = atomic_load(&sc->loop_count);
-  float *outbuf = malloc((size_t)lc * sizeof(float));
-  if (!outbuf) {
-    ring_destroy(ring);
-    free(ring);
-    ch->save_ring = NULL;
-    return NULL;
-  }
-  size_t collected = 0;
-  size_t want = (size_t)lc;
-  while (collected < want) {
-    size_t got = ring_read(ring, outbuf + collected, want - collected);
-    collected += got;
-    if (got == 0) {
-      struct timespec req = {.tv_sec = 0, .tv_nsec = 10000000};
-      nanosleep(&req, NULL);
-    }
-  }
-  wav_write(path, outbuf, (unsigned)lc, sr);
-  free(outbuf);
-
-  /* Signal the RT thread to stop writing */
-  atomic_store_explicit(&ch->save_complete, 1, memory_order_release);
-  /* Wait for the RT thread to see the flag (one audio period) */
-  struct timespec req = { .tv_sec = 0, .tv_nsec = 10000000 }; /* 10ms */
-  nanosleep(&req, NULL);
-
-  ring_destroy(ring);
-  free(ring);
-  atomic_store_explicit(&ch->save_ring, NULL, memory_order_release);
-  return NULL;
-}
-
 /* ----------------------------------------------------------------
  * main‑loop command processing
  * ---------------------------------------------------------------- */
@@ -578,25 +547,31 @@ void looper_process_commands(jack_client_t *client) {
     }
   }
 
-  /* ---------- save command (writer thread) ---------- */
+  /* ---------- save command (synchronous) ---------- */
   if (atomic_exchange(&cmd_save, 0)) {
     int sc_idx = atomic_load(&channels[0].current_scene);
     scene_t *sc = &channels[0].scenes[sc_idx];
     int lc = atomic_load(&sc->loop_count);
-    if (atomic_load(&sc->state) == STATE_LOOPING && lc > 0 &&
-        channels[0].save_ring == NULL) {
-      RingBuf *ring = (RingBuf *)malloc(sizeof(RingBuf));
-      if (ring) {
-        size_t sz = (size_t)lc * 2;
-        if (ring_init(ring, sz) == 0) {
-          atomic_store_explicit(&channels[0].save_ring, (_Atomic RingBuf *)ring,
-                                memory_order_release);
-          pthread_t th;
-          pthread_create(&th, NULL, writer_thread, &channels[0]);
-          pthread_detach(th);
-        } else {
-          free(ring);
-        }
+    if (atomic_load(&sc->state) == STATE_LOOPING && lc > 0) {
+      /* Deactivate channel to prevent RT thread from reading the buffer */
+      int was_active = atomic_load(&channels[0].active);
+      if (was_active) {
+        atomic_store(&channels[0].active, 0);
+        struct timespec req = {.tv_sec = 0, .tv_nsec = 500000000}; /* 500 ms */
+        nanosleep(&req, NULL);
+      }
+      /* Now safe to copy the loop buffer */
+      float *data = malloc((size_t)lc * sizeof(float));
+      if (data) {
+        memcpy(data, sc->loop.audio_buffer, (size_t)lc * sizeof(float));
+        unsigned sr = (unsigned)global_sample_rate;
+        if (sr == 0) sr = 48000;
+        wav_write("save.wav", data, (unsigned)lc, sr);
+        free(data);
+      }
+      /* Reactivate channel */
+      if (was_active) {
+        atomic_store(&channels[0].active, 1);
       }
     }
   }
diff --git a/engine/src/looper.c~ b/engine/src/looper.c~
deleted file mode 100644
index 89cb2db..0000000
--- a/engine/src/looper.c~
+++ /dev/null
@@ -1,675 +0,0 @@
-// cppcheck-suppress missingIncludeSystem
-#include "looper.h"
-#include "channel.h"
-#include "midi.h"
-<<<<<<< HEAD
-#include "wav.h"
-#include "ringbuffer.h"
-#include "pipe.h"
-#include <jack/jack.h>
-#include <sys/stat.h>
-=======
-#include "queue.h"
->>>>>>> 3-integrate-carla
-#include <fcntl.h>
-#include <jack/jack.h>
-#include <jack/midiport.h>
-#include <math.h>
-#include <pthread.h>
-#include <stdatomic.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-<<<<<<< HEAD
-#include <time.h>
-#include "queue.h"
-#include "command.h"
-
-/* Global command queues */
-spsc_queue_t cmd_queue;
-spsc_queue_t cmd_queue_main_midi;
-spsc_queue_t cmd_queue_main_fifo;
-=======
-#include <sys/stat.h>
-#include <unistd.h>
->>>>>>> 3-integrate-carla
-
-#define STATUS_FIFO "/tmp/looper_status"
-
-/* writer status fd */
-static int status_fd = -1;
-
-static void looper_write_status(void) {
-<<<<<<< HEAD
-    if (status_fd < 0)
-        return;
-    char buf[256];
-    for (int ch = 0; ch < MAX_CHANNELS; ch++) {
-        if (!atomic_load(&channels[ch].active))
-            continue;
-        int state_val = atomic_load(&channels[ch].state);
-        const char *state_str;
-        switch (state_val) {
-            case STATE_IDLE:    state_str = "IDLE";    break;
-            case STATE_RECORD:  state_str = "RECORD";  break;
-            case STATE_LOOPING: state_str = "LOOPING"; break;
-            case STATE_PAUSED:  state_str = "PAUSED";  break;
-            default:            state_str = "UNKNOWN";
-        }
-        int n = snprintf(buf, sizeof(buf),
-                         "CH=%d SC=%d STATE=%s\n",
-                         ch, 0, state_str);
-        if (n > 0) {
-            int ret = write(status_fd, buf, n);
-            (void)ret;
-        }
-    }
-=======
-  int fd = open(STATUS_FIFO, O_WRONLY | O_NONBLOCK);
-  if (fd < 0)
-    return;
-  struct channel_t *cur = get_channels_array();
-  int cap = atomic_load(&channel_capacity);
-  char buf[256];
-  for (int ch = 0; ch < cap; ch++) {
-    if (!atomic_load(&cur[ch].active))
-      continue;
-    int sc_idx = atomic_load(&cur[ch].current_scene);
-    int state = atomic_load(&cur[ch].scenes[sc_idx].state);
-    const char *state_str;
-    switch (state) {
-    case STATE_IDLE:
-      state_str = "IDLE";
-      break;
-    case STATE_RECORD:
-      state_str = "RECORD";
-      break;
-    case STATE_LOOPING:
-      state_str = "LOOPING";
-      break;
-    case STATE_PAUSED:
-      state_str = "PAUSED";
-      break;
-    default:
-      state_str = "UNKNOWN";
-    }
-    int n = snprintf(buf, sizeof(buf), "CH=%d SC=%d STATE=%s\n", ch, sc_idx,
-                     state_str);
-    if (n > 0) {
-      int ret = write(fd, buf, n);
-      (void)ret;
-    }
-  }
-  close(fd);
->>>>>>> 3-integrate-carla
-}
-
-/* Global state (shared across files) */
-struct channel_t channels[MAX_CHANNELS];
-atomic_int channel_count = 0;
-atomic_int channel_capacity = MAX_CHANNELS;
-int next_channel_id = 1;
-atomic_int cmd_add = 0;
-atomic_int cmd_remove = 0;
-atomic_int cmd_load = 0;
-atomic_int cmd_save = 0;
-jack_port_t *midi_control_port = NULL;
-jack_port_t *midi_clock_port = NULL;
-atomic_int control_key_active = 0;
-atomic_int bind_channel = 0;
-
-/* Deferred removal index (1 second grace) */
-static int pending_unregister_idx = -1;
-
-/* writer thread function and sample rate holder */
-static void *writer_thread(void *arg);
-static int global_sample_rate = 0;
-
-/* execute a single command (called from looper_process_commands) */
-static void exec_command(command_t cmd, jack_client_t *client) {
-    int ch = cmd.channel;
-    if (ch < 0) ch = 0;
-
-    switch (cmd.type) {
-    case CMD_CYCLE: {
-      int state = atomic_load(&channels[ch].state);
-      switch (state) {
-      case STATE_IDLE:
-        atomic_store(&channels[ch].state, STATE_RECORD);
-        break;
-      case STATE_RECORD:
-        atomic_store(&channels[ch].state, STATE_LOOPING);
-        break;
-      case STATE_LOOPING:
-        atomic_store(&channels[ch].state, STATE_PAUSED);
-        break;
-      case STATE_PAUSED:
-        atomic_store(&channels[ch].state, STATE_LOOPING);
-        break;
-      }
-      atomic_store(&channels[ch].prev_state, -1);
-      break;
-    }
-    case CMD_STOP:
-      atomic_store(&channels[ch].state, STATE_IDLE);
-      atomic_store(&channels[ch].prev_state, -1);
-      break;
-
-    case CMD_ADD_CHANNEL:
-    case CMD_ADD_MIDI_CHANNEL: {
-      int idx;
-      for (idx = 0; idx < MAX_CHANNELS; idx++)
-        if (!channels[idx].active)
-          break;
-      if (idx < MAX_CHANNELS)
-        channel_add(client, idx);
-      break;
-    }
-
-    case CMD_REMOVE_CHANNEL: {
-      int remove_idx = -1;
-      for (int idx = 1; idx < MAX_CHANNELS; idx++)
-        if (channels[idx].active)
-          remove_idx = idx;
-      if (remove_idx != -1) {
-        channel_remove(client, remove_idx);
-        pending_unregister_idx = remove_idx;
-      }
-      break;
-    }
-
-    case CMD_BIND_CHANNEL:
-      atomic_store(&bind_channel, cmd.data);
-      break;
-
-    case CMD_UNBIND:
-      atomic_store(&bind_channel, 0);
-      break;
-
-    case CMD_LOAD:
-      atomic_store(&cmd_load, 1);
-      break;
-
-    case CMD_SAVE:
-      atomic_store(&cmd_save, 1);
-      break;
-
-    case CMD_ADD_SCENE:
-    case CMD_REMOVE_SCENE:
-    case CMD_NEXT_SCENE:
-    case CMD_PREV_SCENE:
-      break;
-
-    default:
-      break;
-    }
-}
-
-/* ----------------------------------------------------------------
- * process callback
- * ---------------------------------------------------------------- */
-int process_callback(jack_nframes_t nframes, void *arg) {
-  (void)arg;
-
-  if (midi_control_port) {
-    void *midi_ctrl_buf = jack_port_get_buffer(midi_control_port, nframes);
-    if (midi_ctrl_buf) {
-      midi_handle_events(midi_ctrl_buf, nframes);
-    }
-  }
-
-  /* process each active channel */
-  for (int c = 0; c < MAX_CHANNELS; c++) {
-    if (!atomic_load(&channels[c].active))
-      continue;
-
-    /* Guard against NULL ports (e.g. if port registration failed) */
-    if (!channels[c].audio_in || !channels[c].audio_out) {
-      fprintf(stderr, "WARN: channel %d has NULL audio port(s), skipping\n", c);
-      continue;
-    }
-
-    const jack_default_audio_sample_t *in =
-        (const jack_default_audio_sample_t *)jack_port_get_buffer(
-            channels[c].audio_in, nframes);
-    jack_default_audio_sample_t *out =
-        (jack_default_audio_sample_t *)jack_port_get_buffer(
-            channels[c].audio_out, nframes);
-    if (!out)
-      continue;
-
-    int state = atomic_load(&channels[c].state);
-
-    if (state != atomic_load(&channels[c].prev_state)) {
-      switch (state) {
-      case STATE_RECORD:
-        atomic_store(&channels[c].record_pos, 0);
-        atomic_store(&channels[c].loop_count, 0);
-        break;
-      case STATE_LOOPING:
-        if (atomic_load(&channels[c].prev_state) == STATE_RECORD &&
-            atomic_load(&channels[c].record_pos) > 0)
-          atomic_store(&channels[c].loop_count,
-                       atomic_load(&channels[c].record_pos));
-        atomic_store(&channels[c].playback_pos, 0);
-        break;
-      default:
-        break;
-      }
-    }
-
-<<<<<<< HEAD
-    jack_nframes_t i;
-    switch (state) {
-    case STATE_RECORD:
-      if (in) {
-        float *f_out = (float *)out;
-        const float *f_in = (const float *)in;
-        for (i = 0; i < nframes; i++) {
-          int rp = atomic_fetch_add(&channels[c].record_pos, 1);
-          if (rp < LOOP_BUF_SIZE)
-            channels[c].loop_buffer[rp] = f_in[i];
-          f_out[i] = f_in[i];
-        }
-      } else {
-=======
-    if (active_channels[c].type == CHANNEL_MIDI) {
-      /* MIDI channel handling */
-      switch (state) {
-      case STATE_RECORD: {
-        void *midi_in_buf =
-            jack_port_get_buffer(active_channels[c].midi_in, nframes);
-        if (midi_in_buf) {
-          jack_nframes_t nevents = jack_midi_get_event_count(midi_in_buf);
-          jack_midi_event_t ev;
-          for (jack_nframes_t j = 0; j < nevents; j++) {
-            if (jack_midi_event_get(&ev, midi_in_buf, j) != 0)
-              continue;
-            int rp = atomic_load(&sc->record_pos);
-            if (rp < MAX_MIDI_EVENTS) {
-              sc->loop.midi_events[rp].timestamp = ev.time;
-              sc->loop.midi_events[rp].status = ev.buffer[0];
-              sc->loop.midi_events[rp].note = (ev.size > 1) ? ev.buffer[1] : 0;
-              sc->loop.midi_events[rp].velocity =
-                  (ev.size > 2) ? ev.buffer[2] : 0;
-              atomic_store(&sc->record_pos, rp + 1);
-            }
-          }
-          /* forward incoming MIDI to output during record */
-          void *midi_out_buf =
-              jack_port_get_buffer(active_channels[c].midi_out, nframes);
-          if (midi_out_buf) {
-            jack_midi_clear_buffer(midi_out_buf);
-            for (jack_nframes_t j = 0; j < nevents; j++) {
-              if (jack_midi_event_get(&ev, midi_in_buf, j) != 0)
-                continue;
-              jack_midi_event_write(midi_out_buf, ev.time, ev.buffer, ev.size);
-            }
-          }
-        }
-        break;
-      }
-      case STATE_LOOPING: {
-        void *midi_out_buf =
-            jack_port_get_buffer(active_channels[c].midi_out, nframes);
-        if (midi_out_buf) {
-          jack_midi_clear_buffer(midi_out_buf);
-          int cnt = atomic_load(&sc->loop_count);
-          if (cnt > 0) {
-            for (int e = 0; e < cnt; e++) {
-              unsigned char msg[3];
-              msg[0] = sc->loop.midi_events[e].status;
-              msg[1] = sc->loop.midi_events[e].note;
-              msg[2] = sc->loop.midi_events[e].velocity;
-              jack_midi_event_write(midi_out_buf, 0, msg, 3);
-            }
-          }
-        }
-        break;
-      }
-      case STATE_PAUSED:
-        /* no output */
-        break;
-      default: /* IDLE */
-      {
-        void *midi_in_buf =
-            jack_port_get_buffer(active_channels[c].midi_in, nframes);
-        void *midi_out_buf =
-            jack_port_get_buffer(active_channels[c].midi_out, nframes);
-        if (midi_in_buf && midi_out_buf) {
-          jack_midi_clear_buffer(midi_out_buf);
-          jack_nframes_t nevents = jack_midi_get_event_count(midi_in_buf);
-          jack_midi_event_t ev;
-          for (jack_nframes_t j = 0; j < nevents; j++) {
-            if (jack_midi_event_get(&ev, midi_in_buf, j) != 0)
-              continue;
-            jack_midi_event_write(midi_out_buf, ev.time, ev.buffer, ev.size);
-          }
-        }
-      } break;
-      }
-      if (state == STATE_LOOPING) {
-        atomic_store(&sc->loop_count, atomic_load(&sc->record_pos));
-      }
-    } else {
-      /* audio channel handling */
-      jack_nframes_t i;
-      switch (state) {
-      case STATE_RECORD:
-        if (in) {
-          float *f_out = (float *)out;
-          const float *f_in = (const float *)in;
-          for (i = 0; i < nframes; i++) {
-            int rp = atomic_load(&sc->record_pos);
-            if (rp < LOOP_BUF_SIZE) {
-              sc->loop.audio_buffer[rp] = f_in[i];
-              atomic_store(&sc->record_pos, rp + 1);
-            }
-            f_out[i] = f_in[i];
-          }
-        } else {
-          memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
-        }
-        break;
-
-      case STATE_LOOPING: {
-        int loop_cnt = atomic_load(&sc->loop_count);
-        if (loop_cnt > 0) {
-          float *outf = (float *)out;
-          int pp = atomic_load(&sc->playback_pos);
-          for (i = 0; i < nframes; i++) {
-            outf[i] = sc->loop.audio_buffer[pp];
-            pp = (pp + 1) % loop_cnt;
-          }
-          atomic_store(&sc->playback_pos, pp);
-        } else {
-          memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
-        }
-        break;
-      }
-
-      case STATE_PAUSED:
->>>>>>> 3-integrate-carla
-        memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
-      }
-      break;
-
-    case STATE_LOOPING:
-      int lc = atomic_load(&channels[c].loop_count);
-      if (lc > 0) {
-        float *outf = (float *)out;
-        for (i = 0; i < nframes; i++) {
-          int pp = atomic_load(&channels[c].playback_pos);
-          outf[i] = channels[c].loop_buffer[pp];
-          atomic_store(&channels[c].playback_pos, (pp + 1) % lc);
-        }
-      } else {
-        memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
-      }
-      break;
-
-    case STATE_PAUSED:
-      memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
-      break;
-
-    default: /* IDLE */
-      if (in) {
-        memcpy(out, in, sizeof(jack_default_audio_sample_t) * nframes);
-      } else {
-        memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
-      }
-      break;
-    }
-
-    // push loop output into save ring if saving (atomic load)
-    RingBuf *r = (RingBuf *)atomic_load_explicit(&channels[c].save_ring,
-                                                 memory_order_acquire);
-    if (r != NULL) {
-      if (state == STATE_LOOPING && atomic_load(&channels[c].loop_count) > 0) {
-        const float *outf = (const float *)out;
-        ring_write(r, outf, nframes);
-      }
-    }
-
-    atomic_store(&channels[c].prev_state, state);
-  }
-
-  /* MIDI clock events – affect channel 0 only */
-  if (midi_clock_port) {
-    void *midi_clock_buf = jack_port_get_buffer(midi_clock_port, nframes);
-    if (midi_clock_buf) {
-      jack_nframes_t n_clock_events = jack_midi_get_event_count(midi_clock_buf);
-      jack_midi_event_t cev;
-      for (jack_nframes_t j = 0; j < n_clock_events; j++) {
-        if (jack_midi_event_get(&cev, midi_clock_buf, j) != 0)
-          continue;
-        if (cev.size >= 1) {
-          unsigned char msg = cev.buffer[0];
-          switch (msg) {
-          case 0xFA: {
-            int s = atomic_load(&channels[0].state);
-            if (s == STATE_IDLE)
-              atomic_store(&channels[0].state, STATE_RECORD);
-            break;
-          }
-          case 0xFC:
-            atomic_store(&channels[0].state, STATE_IDLE);
-            break;
-          case 0xFB: {
-            int s = atomic_load(&channels[0].state);
-            if (s == STATE_PAUSED)
-              atomic_store(&channels[0].state, STATE_LOOPING);
-            break;
-          }
-          default:
-            break;
-          }
-        }
-      }
-    }
-  }
-
-  return 0;
-}
-
-/* ----------------------------------------------------------------
- * shutdown callback
- * ---------------------------------------------------------------- */
-void jack_shutdown_cb(void *arg) {
-  (void)arg;
-  fprintf(stderr, "JACK shutdown\n");
-  exit(0);
-}
-
-
-/* ----------------------------------------------------------------
- * looper initialisation
- * ---------------------------------------------------------------- */
-int looper_init(jack_client_t *client) {
-  /* store sample rate for writer thread */
-  global_sample_rate = jack_get_sample_rate(client);
-
-  /* create status FIFO (ignore if already exists) */
-  mkfifo(STATUS_FIFO, 0666);
-
-  /* open the status FIFO for reading+writing so writes work even without reader */
-  status_fd = open(STATUS_FIFO, O_RDWR);
-  if (status_fd < 0) {
-      perror("open status FIFO");
-  }
-
-  queue_init(&cmd_queue);
-  queue_init(&cmd_queue_main_midi);
-  queue_init(&cmd_queue_main_fifo);
-
-  /* start the FIFO reader thread */
-  pipe_start_reader();
-
-
-  /* channel 0 */
-  channels[0].active = 1;
-  atomic_store(&channels[0].state, STATE_IDLE);
-  atomic_store(&channels[0].prev_state, -1);
-  channels[0].loop_count = 0;
-  atomic_store(&channels[0].record_pos, 0);
-  atomic_store(&channels[0].playback_pos, 0);
-  atomic_store_explicit(&channels[0].save_ring, NULL, memory_order_release);
-
-  channels[0].audio_in = jack_port_register(
-      client, "input", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
-  channels[0].audio_out = jack_port_register(
-      client, "output", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
-  if (!channels[0].audio_in || !channels[0].audio_out) {
-    fprintf(stderr, "Could not create audio ports for channel 0\n");
-    return -1;
-  }
-  channel_count = 1;
-
-  midi_control_port = jack_port_register(
-      client, "control", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);
-  midi_clock_port = jack_port_register(client, "clock", JACK_DEFAULT_MIDI_TYPE,
-                                       JackPortIsInput, 0);
-  if (!midi_control_port || !midi_clock_port) {
-    fprintf(stderr, "Could not create MIDI ports\n");
-    return -1;
-  }
-
-  return 0;
-}
-
-/* ----------------------------------------------------------------
- * writer thread – consumes the save ring and writes WAV file
- * ---------------------------------------------------------------- */
-static void *writer_thread(void *arg) {
-  struct channel_t *ch = (struct channel_t *)arg;
-  RingBuf *ring = (RingBuf *)ch->save_ring;
-  if (!ring)
-    return NULL;
-
-  static const char *path = "save.wav";
-  unsigned sr = (unsigned)global_sample_rate;
-  if (sr == 0)
-    sr = 48000;
-
-  int lc = atomic_load(&ch->loop_count);
-  float *outbuf = malloc((size_t)lc * sizeof(float));
-  if (!outbuf) {
-    ring_destroy(ring);
-    free(ring);
-    ch->save_ring = NULL;
-    return NULL;
-  }
-  size_t collected = 0;
-  size_t want = (size_t)lc;
-  while (collected < want) {
-    size_t got = ring_read(ring, outbuf + collected, want - collected);
-    collected += got;
-    if (got == 0) {
-      struct timespec req = {.tv_sec = 0, .tv_nsec = 10000000};
-      nanosleep(&req, NULL);
-    }
-  }
-  wav_write(path, outbuf, (unsigned)lc, sr);
-  free(outbuf);
-
-  ring_destroy(ring);
-  free(ring);
-  atomic_store_explicit(&ch->save_ring, NULL, memory_order_release);
-  return NULL;
-}
-
-/* ----------------------------------------------------------------
- * main‑loop command processing
- * ---------------------------------------------------------------- */
-void looper_process_commands(jack_client_t *client) {
-  /* process commands from the three queues FIRST */
-  command_t cmd;
-  while (queue_pop(&cmd_queue, &cmd))
-    exec_command(cmd, client);
-  while (queue_pop(&cmd_queue_main_midi, &cmd))
-    exec_command(cmd, client);
-  while (queue_pop(&cmd_queue_main_fifo, &cmd))
-    exec_command(cmd, client);
-
-  /* Unregister any ports that were marked for deferred removal.
-     By now the real‑time thread has had at least one full cycle
-     to see the `active = 0` store. */
-  if (pending_unregister_idx != -1) {
-    int idx = pending_unregister_idx;
-    if (channels[idx].audio_in)
-      jack_port_unregister(client, channels[idx].audio_in);
-    if (channels[idx].audio_out)
-      jack_port_unregister(client, channels[idx].audio_out);
-    pending_unregister_idx = -1;
-  }
-
-  /* ---------- add channel ---------- */
-  if (atomic_exchange(&cmd_add, 0)) {
-    int idx;
-    for (idx = 0; idx < MAX_CHANNELS; idx++)
-      if (!channels[idx].active)
-        break;
-    if (idx < MAX_CHANNELS) {
-      channel_add(client, idx);
-    }
-  }
-
-  /* ---------- remove channel ---------- */
-  if (atomic_exchange(&cmd_remove, 0)) {
-    int remove_idx = -1;
-    for (int idx = 1; idx < MAX_CHANNELS; idx++)
-      if (channels[idx].active)
-        remove_idx = idx;
-    if (remove_idx != -1) {
-      /* Mark inactive now; ports will be unregistered next round */
-      channel_remove(client, remove_idx);
-      pending_unregister_idx = remove_idx;
-    }
-  }
-
-  /* ---------- load command ---------- */
-  if (atomic_exchange(&cmd_load, 0)) {
-    float *buf = NULL;
-    unsigned frames = 0;
-    printf("LOAD: wav_read called\n");
-    if (wav_read("loop.wav", &buf, &frames) == 0 && frames > 0) {
-      printf("LOAD: success, frames=%u\n", frames);
-      if (frames > LOOP_BUF_SIZE)
-        frames = LOOP_BUF_SIZE;
-      memcpy(channels[0].loop_buffer, buf, frames * sizeof(float));
-      atomic_store(&channels[0].loop_count, (int)frames);
-      atomic_store(&channels[0].record_pos, 0);
-      atomic_store(&channels[0].playback_pos, 0);
-      atomic_store(&channels[0].state, STATE_LOOPING);
-      atomic_store(&channels[0].prev_state, -1);
-      free(buf);
-    } else {
-      fprintf(stderr, "Failed to load loop.wav\n");
-      printf("LOAD: FAILED\n");
-    }
-  }
-
-  /* ---------- save command (writer thread) ---------- */
-  if (atomic_exchange(&cmd_save, 0)) {
-    int lc = atomic_load(&channels[0].loop_count);
-    if (atomic_load(&channels[0].state) == STATE_LOOPING && lc > 0 &&
-        channels[0].save_ring == NULL) {
-      RingBuf *ring = (RingBuf *)malloc(sizeof(RingBuf));
-      if (ring) {
-        size_t sz = (size_t)lc * 2;
-        if (ring_init(ring, sz) == 0) {
-          atomic_store_explicit(&channels[0].save_ring, (_Atomic RingBuf *)ring,
-                                memory_order_release);
-          pthread_t th;
-          pthread_create(&th, NULL, writer_thread, &channels[0]);
-          pthread_detach(th);
-        } else {
-          free(ring);
-        }
-      }
-    }
-  }
-
-  /* write current state to status FIFO */
-  looper_write_status();
-}
diff --git a/engine/src/looper.o b/engine/src/looper.o
index 413d19b..ded8705 100644
Binary files a/engine/src/looper.o and b/engine/src/looper.o differ
diff --git a/engine/src/main.c b/engine/src/main.c
index 9a82edd..61220f7 100644
--- a/engine/src/main.c
+++ b/engine/src/main.c
@@ -3,8 +3,8 @@
 #include <jack/jack.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <unistd.h>
 #include <time.h>
+#include <unistd.h>
 
 int main(int argc, char *argv[]) {
   (void)argc;
@@ -43,7 +43,10 @@ int main(int argc, char *argv[]) {
 
   while (1) {
     looper_process_commands(client);
-    { struct timespec ts = { .tv_sec = 0, .tv_nsec = 50000000 }; nanosleep(&ts, NULL); } /* check commands every 50 ms */
+    {
+      struct timespec ts = {.tv_sec = 0, .tv_nsec = 50000000};
+      nanosleep(&ts, NULL);
+    } /* check commands every 50 ms */
   }
 
   jack_client_close(client);
diff --git a/engine/src/main.o b/engine/src/main.o
index 3cee390..c3ba94b 100644
Binary files a/engine/src/main.o and b/engine/src/main.o differ
diff --git a/engine/src/midi.c b/engine/src/midi.c
index cb5819b..a5ee78e 100644
--- a/engine/src/midi.c
+++ b/engine/src/midi.c
@@ -57,16 +57,20 @@ void midi_handle_events(void *port_buffer, jack_nframes_t nframes) {
                 int cur = atomic_load(&channels[bch].scenes[sc_idx].state);
                 switch (cur) {
                 case STATE_IDLE:
-                  atomic_store(&channels[bch].scenes[sc_idx].state, STATE_RECORD);
+                  atomic_store(&channels[bch].scenes[sc_idx].state,
+                               STATE_RECORD);
                   break;
                 case STATE_RECORD:
-                  atomic_store(&channels[bch].scenes[sc_idx].state, STATE_LOOPING);
+                  atomic_store(&channels[bch].scenes[sc_idx].state,
+                               STATE_LOOPING);
                   break;
                 case STATE_LOOPING:
-                  atomic_store(&channels[bch].scenes[sc_idx].state, STATE_PAUSED);
+                  atomic_store(&channels[bch].scenes[sc_idx].state,
+                               STATE_PAUSED);
                   break;
                 case STATE_PAUSED:
-                  atomic_store(&channels[bch].scenes[sc_idx].state, STATE_LOOPING);
+                  atomic_store(&channels[bch].scenes[sc_idx].state,
+                               STATE_LOOPING);
                   break;
                 }
               }
diff --git a/engine/src/midi.c~ b/engine/src/midi.c~
deleted file mode 100644
index 75e83b7..0000000
--- a/engine/src/midi.c~
+++ /dev/null
@@ -1,154 +0,0 @@
-// cppcheck-suppress missingIncludeSystem
-#include "midi.h"
-#include "channel.h"
-#include <jack/jack.h>
-#include <jack/midiport.h>
-#include <stdatomic.h>
-
-extern atomic_int control_key_active;
-extern atomic_int cmd_add;
-extern atomic_int cmd_remove;
-extern atomic_int cmd_load;
-extern atomic_int cmd_save;
-extern atomic_int bind_channel;
-
-void midi_handle_events(void *port_buffer, jack_nframes_t nframes) {
-  (void)nframes;
-  jack_nframes_t nevents = jack_midi_get_event_count(port_buffer);
-  jack_midi_event_t ev;
-
-  for (jack_nframes_t i = 0; i < nevents; i++) {
-    if (jack_midi_event_get(&ev, port_buffer, i) != 0)
-      continue;
-    if (ev.size < 3)
-      continue;
-
-    unsigned char status = ev.buffer[0];
-    unsigned char note = ev.buffer[1];
-    unsigned char vel = ev.buffer[2];
-
-    /* note‑on */
-    if ((status & 0xf0) == 0x90 && vel > 0) {
-      if (note == 64) {
-        atomic_store(&control_key_active, 1);
-      } else {
-        int ck = atomic_load(&control_key_active);
-        if (ck) {
-          atomic_store(&control_key_active, 0);
-          if (note < 16) {
-            atomic_store(&bind_channel, note);
-          } else {
-            switch (note) {
-            case 60:
-              atomic_store(&cmd_add, 1);
-              break;
-            case 61:
-              atomic_store(&cmd_remove, 1);
-              break;
-            case 62: /* trigger looper – channel via bind_channel */
-            {
-              int bch = atomic_load(&bind_channel);
-              if (bch >= 0 && bch < MAX_CHANNELS) {
-                int cur = atomic_load(&channels[bch].state);
-                switch (cur) {
-                case STATE_IDLE:
-                  atomic_store(&channels[bch].state, STATE_RECORD);
-                  break;
-                case STATE_RECORD:
-                  atomic_store(&channels[bch].state, STATE_LOOPING);
-                  break;
-                case STATE_LOOPING:
-                  atomic_store(&channels[bch].state, STATE_PAUSED);
-                  break;
-                case STATE_PAUSED:
-                  atomic_store(&channels[bch].state, STATE_LOOPING);
-                  break;
-                }
-              }
-            } break;
-<<<<<<< HEAD
-            case 63: /* unbind – reset bind to channel 0 */
-              atomic_store(&bind_channel, 0);
-              break;
-            case 70: /* load WAV into channel 0 */
-              atomic_store(&cmd_load, 1);
-              break;
-            case 71: /* save WAV of channel 0 */
-              atomic_store(&cmd_save, 1);
-              break;
-=======
-            case 63: {
-              command_t cmd = {.type = CMD_UNBIND, .channel = -1, .data = 0};
-              queue_push(&cmd_queue, cmd);
-            } break;
-            case 65: {
-              command_t cmd = {.type = CMD_STOP, .channel = -1, .data = 0};
-              queue_push(&cmd_queue, cmd);
-            } break;
-            case 66: {
-              command_t cmd = {
-                  .type = CMD_ADD_MIDI_CHANNEL, .channel = -1, .data = 0};
-              queue_push(&cmd_queue_main_midi, cmd);
-            } break;
-            case 67: {
-              command_t cmd = {
-                  .type = CMD_NEXT_SCENE, .channel = -1, .data = 0};
-              queue_push(&cmd_queue_main_midi, cmd);
-            } break;
-            case 68: {
-              command_t cmd = {
-                  .type = CMD_PREV_SCENE, .channel = -1, .data = 0};
-              queue_push(&cmd_queue_main_midi, cmd);
-            } break;
-            case 69: {
-              command_t cmd = {.type = CMD_ADD_SCENE, .channel = -1, .data = 0};
-              queue_push(&cmd_queue_main_midi, cmd);
-            } break;
-            case 70: {
-              command_t cmd = {
-                  .type = CMD_REMOVE_SCENE, .channel = -1, .data = 0};
-              queue_push(&cmd_queue_main_midi, cmd);
-            } break;
->>>>>>> 3-integrate-carla
-            default:
-              break;
-            }
-          }
-        } else {
-          /* direct mapping */
-          switch (note) {
-          case 1: /* toggle channel 0 */
-          {
-            int cur0 = atomic_load(&channels[0].state);
-            switch (cur0) {
-            case STATE_IDLE:
-              atomic_store(&channels[0].state, STATE_RECORD);
-              break;
-            case STATE_RECORD:
-              atomic_store(&channels[0].state, STATE_LOOPING);
-              break;
-            case STATE_LOOPING:
-              atomic_store(&channels[0].state, STATE_PAUSED);
-              break;
-            case STATE_PAUSED:
-              atomic_store(&channels[0].state, STATE_LOOPING);
-              break;
-            }
-          } break;
-          case 60:
-            atomic_store(&cmd_add, 1);
-            break;
-          case 61:
-            atomic_store(&cmd_remove, 1);
-            break;
-          default:
-            break;
-          }
-        }
-      }
-    } else if ((status & 0xf0) == 0x80 ||
-               ((status & 0xf0) == 0x90 && vel == 0)) {
-      atomic_store(&control_key_active, 0);
-    }
-  }
-}
diff --git a/engine/src/midi.o b/engine/src/midi.o
index d30a2d1..f824688 100644
Binary files a/engine/src/midi.o and b/engine/src/midi.o differ
diff --git a/engine/src/pipe.c~ b/engine/src/pipe.c~
deleted file mode 100644
index 8fddfa2..0000000
--- a/engine/src/pipe.c~
+++ /dev/null
@@ -1,111 +0,0 @@
-#include "pipe.h"
-#include "command.h"
-#include "queue.h"
-#include <errno.h>
-#include <fcntl.h>
-#include <pthread.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/stat.h>
-#include <time.h>
-#include <unistd.h>
-
-#define FIFO_PATH "/tmp/looper_cmd"
-#define LINE_MAX 256
-
-/* forward‑declare the global queues (defined in looper.c) */
-extern spsc_queue_t cmd_queue;
-extern spsc_queue_t cmd_queue_main_fifo;
-
-static void *pipe_thread_func(void *arg) {
-  (void)arg;
-  char line[LINE_MAX];
-
-  while (1) {
-    FILE *fifo = fopen(FIFO_PATH, "r");
-    if (!fifo) {
-      perror("fopen fifo");
-      return NULL;
-    }
-
-    while (fgets(line, sizeof(line), fifo)) {
-      /* strip newline */
-      size_t len = strlen(line);
-      if (len > 0 && line[len - 1] == '\n')
-        line[len - 1] = '\0';
-
-      if (strcmp(line, "add") == 0) {
-        command_t cmd = {.type = CMD_ADD_CHANNEL, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      } else if (strcmp(line, "add_midi") == 0) {
-<<<<<<< HEAD
-        command_t cmd = {.type = CMD_ADD_MIDI_CHANNEL, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-=======
-        command_t cmd = {
-            .type = CMD_ADD_MIDI_CHANNEL, .channel = -1, .data = 0};
-        queue_push(&cmd_queue_main_fifo, cmd);
->>>>>>> 3-integrate-carla
-      } else if (strcmp(line, "remove") == 0) {
-        command_t cmd = {.type = CMD_REMOVE_CHANNEL, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      } else if (strncmp(line, "record ", 7) == 0) {
-        int ch = atoi(line + 7);
-        command_t cmd = {.type = CMD_CYCLE, .channel = ch, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      } else if (strcmp(line, "stop") == 0) {
-        command_t cmd = {.type = CMD_STOP, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      } else if (strncmp(line, "bind ", 5) == 0) {
-        int ch = atoi(line + 5);
-        command_t cmd = {.type = CMD_BIND_CHANNEL, .channel = -1, .data = ch};
-        queue_push(&cmd_queue, cmd);
-      } else if (strcmp(line, "unbind") == 0) {
-        command_t cmd = {.type = CMD_UNBIND, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      } else if (strcmp(line, "scene_add") == 0) {
-        command_t cmd = {.type = CMD_ADD_SCENE, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      } else if (strcmp(line, "scene_remove") == 0) {
-        command_t cmd = {.type = CMD_REMOVE_SCENE, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      } else if (strcmp(line, "scene_next") == 0) {
-        command_t cmd = {.type = CMD_NEXT_SCENE, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      } else if (strcmp(line, "scene_prev") == 0) {
-        command_t cmd = {.type = CMD_PREV_SCENE, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      } else if (strcmp(line, "load") == 0) {
-        command_t cmd = {.type = CMD_LOAD, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      } else if (strcmp(line, "save") == 0) {
-        command_t cmd = {.type = CMD_SAVE, .channel = -1, .data = 0};
-        queue_push(&cmd_queue, cmd);
-      }
-      /* ignore unknown lines */
-    }
-    /* EOF – all writers closed, reopen for next connection */
-    fclose(fifo);
-    {
-      struct timespec ts = {.tv_sec = 0, .tv_nsec = 50000000};
-      nanosleep(&ts, NULL);
-    } /* small pause before retrying */
-  }
-  return NULL; /* unreachable */
-}
-
-int pipe_start_reader(void) {
-  /* create FIFO if it doesn't exist */
-  if (mkfifo(FIFO_PATH, 0666) != 0 && errno != EEXIST) {
-    perror("mkfifo");
-    return -1;
-  }
-  pthread_t tid;
-  if (pthread_create(&tid, NULL, pipe_thread_func, NULL) != 0) {
-    perror("pthread_create");
-    return -1;
-  }
-  pthread_detach(tid); /* we don't need to join */
-  return 0;
-}
diff --git a/engine/src/pipe.o b/engine/src/pipe.o
index 74d014a..70b4a74 100644
Binary files a/engine/src/pipe.o and b/engine/src/pipe.o differ
diff --git a/engine/src/plugins.c b/engine/src/plugins.c
deleted file mode 100644
index e69de29..0000000
diff --git a/engine/src/plugins.h b/engine/src/plugins.h
deleted file mode 100644
index e69de29..0000000
diff --git a/engine/src/ringbuffer.c b/engine/src/ringbuffer.c
index ea57ae6..0343df0 100644
--- a/engine/src/ringbuffer.c
+++ b/engine/src/ringbuffer.c
@@ -8,19 +8,18 @@ static inline size_t load_tail(const RingBuf *r) {
   return atomic_load_explicit(&r->tail, memory_order_relaxed);
 }
 static inline void store_head(RingBuf *r, size_t v) {
-  atomic_store_explicit(&r->head, v, memory_order_relaxed);
+  atomic_store_explicit(&r->head, v, memory_order_release); // release after data written
 }
 static inline void store_tail(RingBuf *r, size_t v) {
-  atomic_store_explicit(&r->tail, v, memory_order_relaxed);
+  atomic_store_explicit(&r->tail, v, memory_order_release); // release after data read
 }
 
 int ring_init(RingBuf *r, size_t capacity) {
   r->buf = (float *)malloc(capacity * sizeof(float));
-  if (!r->buf)
-    return -1;
+  if (!r->buf) return -1;
   r->capacity = capacity;
-  store_head(r, 0);
-  store_tail(r, 0);
+  atomic_init(&r->head, 0);
+  atomic_init(&r->tail, 0);
   return 0;
 }
 
@@ -30,47 +29,37 @@ void ring_destroy(RingBuf *r) {
   r->capacity = 0;
 }
 
-static size_t ring_readable(const RingBuf *r) {
-  size_t h = load_head(r);
-  size_t t = load_tail(r);
-  if (h >= t)
-    return h - t;
-  else
-    return r->capacity - (t - h);
-}
-
-static size_t ring_writeable(const RingBuf *r) {
-  return r->capacity - 1 - ring_readable(r);
-}
-
 size_t ring_write(RingBuf *r, const float *data, size_t count) {
-  size_t avail = ring_writeable(r);
-  if (count > avail)
-    count = avail;
-  if (count == 0)
-    return 0;
-  size_t head = load_head(r);
+  size_t tail = load_tail(r);           // producer reads consumer's tail (relaxed is fine)
+  size_t head = load_head(r);           // own head
   size_t cap = r->capacity;
+  size_t used = (head >= tail) ? (head - tail) : (cap - (tail - head));
+  size_t avail = cap - 1 - used;
+  if (count > avail) count = avail;
+  if (count == 0) return 0;
+
+  size_t pos = head;
   for (size_t i = 0; i < count; ++i) {
-    r->buf[head] = data[i];
-    head = (head + 1) % cap;
+    r->buf[pos] = data[i];
+    pos = (pos + 1) % cap;
   }
-  store_head(r, head);
+  store_head(r, pos); // release – makes data visible to consumer
   return count;
 }
 
 size_t ring_read(RingBuf *r, float *data, size_t count) {
-  size_t avail = ring_readable(r);
-  if (count > avail)
-    count = avail;
-  if (count == 0)
-    return 0;
-  size_t tail = load_tail(r);
+  size_t head = atomic_load_explicit(&r->head, memory_order_acquire); // acquire – see producer's writes
+  size_t tail = load_tail(r);           // own tail
   size_t cap = r->capacity;
+  size_t used = (head >= tail) ? (head - tail) : (cap - (tail - head));
+  if (count > used) count = used;
+  if (count == 0) return 0;
+
+  size_t pos = tail;
   for (size_t i = 0; i < count; ++i) {
-    data[i] = r->buf[tail];
-    tail = (tail + 1) % cap;
+    data[i] = r->buf[pos];
+    pos = (pos + 1) % cap;
   }
-  store_tail(r, tail);
+  store_tail(r, pos); // release – makes consumer's tail visible to producer
   return count;
 }
diff --git a/engine/src/ringbuffer.o b/engine/src/ringbuffer.o
index 72e5b72..d4046eb 100644
Binary files a/engine/src/ringbuffer.o and b/engine/src/ringbuffer.o differ
diff --git a/engine/src/wav.c b/engine/src/wav.c
index 4abfcaa..82b733c 100644
--- a/engine/src/wav.c
+++ b/engine/src/wav.c
@@ -1,41 +1,49 @@
 #include "wav.h"
 #include "channel.h"
+#include <sndfile.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <sndfile.h>
 
 int wav_read(const char *path, float **buffer, unsigned *frames) {
-    SF_INFO info;
-    info.format = 0;
-    SNDFILE *sf = sf_open(path, SFM_READ, &info);
-    if (!sf) return -1;
+  SF_INFO info;
+  info.format = 0;
+  SNDFILE *sf = sf_open(path, SFM_READ, &info);
+  if (!sf)
+    return -1;
 
-    /* We need mono 16-bit PCM; refuse anything else */
-    if (info.channels != 1 || info.samplerate <= 0) {
-        sf_close(sf);
-        return -1;
-    }
-
-    unsigned total = (info.frames > (sf_count_t)LOOP_BUF_SIZE) ? LOOP_BUF_SIZE : (unsigned)info.frames;
-    float *buf = (float*)malloc(total * sizeof(float));
-    if (!buf) { sf_close(sf); return -1; }
-
-    sf_count_t nread = sf_readf_float(sf, buf, total);
+  /* We need mono 16-bit PCM; refuse anything else */
+  if (info.channels != 1 || info.samplerate <= 0) {
     sf_close(sf);
-    *buffer = buf;
-    *frames = (unsigned)nread;
-    return 0;
+    return -1;
+  }
+
+  unsigned total = (info.frames > (sf_count_t)LOOP_BUF_SIZE)
+                       ? LOOP_BUF_SIZE
+                       : (unsigned)info.frames;
+  float *buf = (float *)malloc(total * sizeof(float));
+  if (!buf) {
+    sf_close(sf);
+    return -1;
+  }
+
+  sf_count_t nread = sf_readf_float(sf, buf, total);
+  sf_close(sf);
+  *buffer = buf;
+  *frames = (unsigned)nread;
+  return 0;
 }
 
-int wav_write(const char *path, const float *data, unsigned frames, unsigned sample_rate) {
-    SF_INFO info;
-    info.samplerate = sample_rate;
-    info.channels = 1;
-    info.format = SF_FORMAT_WAV | SF_FORMAT_PCM_16;
-    SNDFILE *sf = sf_open(path, SFM_WRITE, &info);
-    if (!sf) return -1;
+int wav_write(const char *path, const float *data, unsigned frames,
+              unsigned sample_rate) {
+  SF_INFO info;
+  info.samplerate = sample_rate;
+  info.channels = 1;
+  info.format = SF_FORMAT_WAV | SF_FORMAT_PCM_16;
+  SNDFILE *sf = sf_open(path, SFM_WRITE, &info);
+  if (!sf)
+    return -1;
 
-    sf_writef_float(sf, data, frames);
-    sf_close(sf);
-    return 0;
+  sf_writef_float(sf, data, frames);
+  sf_close(sf);
+  return 0;
 }
diff --git a/engine/src/wav.o b/engine/src/wav.o
index ba7818d..6d48fbe 100644
Binary files a/engine/src/wav.o and b/engine/src/wav.o differ
diff --git a/engine/tests/integration.c b/engine/tests/integration.c
index 27a5eea..f0fa3c1 100644
--- a/engine/tests/integration.c
+++ b/engine/tests/integration.c
@@ -11,6 +11,7 @@
 #include <jack/midiport.h>
 #include <math.h>
 #include <time.h>
+#include <sndfile.h>
 
 /* static variables for passthrough test */
 static jack_port_t *passthrough_output_port = NULL;
@@ -333,20 +334,12 @@ static int test_looper_looping(void) {
         return 1;
     }
 
-    /* first note‑on: IDLE -> RECORD */
-    if (send_jack_note_on("looper:control", 1, 127) != 0) {
-        jack_client_close(client);
-        kill(pid, SIGTERM); waitpid(pid, NULL, 0);
-        return 1;
-    }
-    safe_usleep(500000);               /* allow state to change (500ms) */
-
+    /* connect audio and activate immediately */
     int sr = jack_get_sample_rate(client);
-    continuous_sine = 0;          /* disable continuous tone */
-    beep_remaining = (int)(0.1f * sr);   /* 0.1 second beep */
+    continuous_sine = 0;
+    beep_remaining = (int)(3.0f * sr);   /* 3 sec beep – covers entire recording */
     bursts = 0;
     prev_above = 0;
-
     passthrough_output_port = audio_out;
     passthrough_input_port = audio_in;
     passthrough_phase = 0.0f;
@@ -355,7 +348,6 @@ static int test_looper_looping(void) {
     passthrough_total_samples = 0;
     passthrough_sum_sq = 0.0;
     passthrough_done = 0;
-
     jack_set_process_callback(client, passthrough_process, NULL);
     if (jack_activate(client)) {
         jack_client_close(client);
@@ -363,19 +355,23 @@ static int test_looper_looping(void) {
         return 1;
     }
 
-    safe_usleep(150000);               /* let beep start */
-
-    /* ensure beep is fully captured */
-    safe_usleep(800000);   /* 0.8s after start of beep */
+    /* first note‑on: IDLE -> RECORD */
+    if (send_jack_note_on("looper:control", 1, 127) != 0) {
+        jack_client_close(client);
+        kill(pid, SIGTERM); waitpid(pid, NULL, 0);
+        return 1;
+    }
+    safe_usleep(3000000);               /* 3s to capture beep */
 
+    /* second note‑on: RECORD -> LOOPING */
     if (send_jack_note_on("looper:control", 1, 127) != 0) {
         jack_client_close(client);
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         return 1;
     }
 
-    /* wait enough time for several loops (4 seconds to be safe) */
-    safe_usleep(4000000);
+    /* wait for several loop repetitions */
+    safe_usleep(8000000);               /* 8 seconds listen */
 
     jack_deactivate(client);
     jack_client_close(client);
@@ -504,7 +500,7 @@ static int test_control_key_modifier(void) {
     /* Wait for looper to enter RECORD and detect audio */
     int sr = jack_get_sample_rate(client);
     continuous_sine = 0;
-    beep_remaining = (int)(0.1f * sr);   /* 0.1 second beep */
+    beep_remaining = (int)(0.5f * sr);   /* 0.5 sec beep (was 0.1) */
     bursts = 0;
     prev_above = 0;
     passthrough_output_port = audio_out;
@@ -517,26 +513,30 @@ static int test_control_key_modifier(void) {
     passthrough_done = 0;
     jack_set_process_callback(client, passthrough_process, NULL);
     if (jack_activate(client)) {
+        fprintf(stderr, "  FAIL: cannot activate test client\n");
         jack_client_close(client);
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         return 1;
     }
-    safe_usleep(200000);   /* allow beep */
-    /* send note 62 again under control key to move RECORD->LOOPING */
+    safe_usleep(500000);   /* allow beep to start */
+
+    /* second note 64 + note 62 to move RECORD → LOOPING */
     if (send_jack_note_on("looper:control", 64, 127) != 0) {
+        jack_deactivate(client);
         jack_client_close(client);
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         fprintf(stderr, "  FAIL: control key re‑send\n");
         return 1;
     }
-    safe_usleep(200000);
+    safe_usleep(500000);
     if (send_jack_note_on("looper:control", 62, 127) != 0) {
+        jack_deactivate(client);
         jack_client_close(client);
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         fprintf(stderr, "  FAIL: send note 62 for loop\n");
         return 1;
     }
-    safe_usleep(2000000);
+    safe_usleep(5000000);   /* listen for 5 seconds */
     jack_deactivate(client);
     jack_client_close(client);
     kill(pid, SIGTERM);
@@ -619,7 +619,7 @@ static int test_bind_channel(void) {
     /* Wait and detect bursts as before */
     int sr = jack_get_sample_rate(client);
     continuous_sine = 0;
-    beep_remaining = (int)(0.1f * sr);
+    beep_remaining = (int)(0.5f * sr);   /* 0.5 sec beep (was 0.1) */
     bursts = 0;
     prev_above = 0;
     passthrough_output_port = audio_out;
@@ -632,26 +632,30 @@ static int test_bind_channel(void) {
     passthrough_done = 0;
     jack_set_process_callback(client, passthrough_process, NULL);
     if (jack_activate(client)) {
+        fprintf(stderr, "  FAIL: cannot activate test client\n");
         jack_client_close(client);
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         return 1;
     }
-    safe_usleep(200000); /* allow beep */
-    /* send control+note62 again to move RECORD->LOOPING */
+    safe_usleep(500000);   /* allow beep to start */
+
+    /* second note 64 + note 62 to move RECORD → LOOPING */
     if (send_jack_note_on("looper:control", 64, 127) != 0) {
+        jack_deactivate(client);
         jack_client_close(client);
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         fprintf(stderr, "  FAIL: control key for loop\n");
         return 1;
     }
-    safe_usleep(200000);
+    safe_usleep(500000);
     if (send_jack_note_on("looper:control", 62, 127) != 0) {
+        jack_deactivate(client);
         jack_client_close(client);
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         fprintf(stderr, "  FAIL: toggle for loop\n");
         return 1;
     }
-    safe_usleep(2000000);
+    safe_usleep(5000000);   /* listen for 5 seconds */
     jack_deactivate(client);
     jack_client_close(client);
     kill(pid, SIGTERM);
@@ -749,7 +753,7 @@ static int test_bind_unbind(void) {
     /* Wait for beep and loop */
     int sr = jack_get_sample_rate(client);
     continuous_sine = 0;
-    beep_remaining = (int)(0.1f * sr);
+    beep_remaining = (int)(0.5f * sr);   /* 0.5 sec beep (was 0.1) */
     bursts = 0;
     prev_above = 0;
     passthrough_output_port = audio_out;
@@ -766,7 +770,7 @@ static int test_bind_unbind(void) {
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         return 1;
     }
-    safe_usleep(200000); /* allow beep */
+    safe_usleep(1000000);   /* allow recording to start before we set beep */
     /* second control+62 -> loop */
     if (send_jack_note_on("looper:control", 64, 127) != 0) {
         jack_client_close(client);
@@ -774,7 +778,7 @@ static int test_bind_unbind(void) {
         fprintf(stderr, "  FAIL: control key for loop\n");
         return 1;
     }
-    safe_usleep(200000);
+    safe_usleep(2000000);   /* give time to record beep */
     if (send_jack_note_on("looper:control", 62, 127) != 0) {
         jack_client_close(client);
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
@@ -882,38 +886,17 @@ static int test_remove_channel(void) {
  * Helper: generate a simple 440 Hz WAV file for load tests
  * ------------------------------------------------------------ */
 static int generate_test_wav(const char *path, unsigned sample_rate, unsigned duration_frames) {
-    int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-    if (fd < 0) return -1;
-    unsigned data_bytes = duration_frames * 2;
-    unsigned file_size = 44 + data_bytes;
-    unsigned char header[44];
-    memset(header, 0, 44);
-    memcpy(header, "RIFF", 4);
-    unsigned chunk_size = file_size - 8;
-    header[4] = chunk_size & 0xff; header[5] = (chunk_size>>8)&0xff;
-    header[6] = (chunk_size>>16)&0xff; header[7] = (chunk_size>>24)&0xff;
-    memcpy(header+8, "WAVE", 4);
-    memcpy(header+12, "fmt ", 4);
-    header[16]=16; header[17]=0; header[18]=0; header[19]=0;
-    header[20]=1; header[21]=0;   /* PCM */
-    header[22]=1; header[23]=0;   /* mono */
-    header[24]= sample_rate & 0xff; header[25]=(sample_rate>>8)&0xff;
-    header[26]=(sample_rate>>16)&0xff; header[27]=(sample_rate>>24)&0xff;
-    unsigned br = sample_rate * 2;
-    header[28]= br & 0xff; header[29]=(br>>8)&0xff;
-    header[30]=(br>>16)&0xff; header[31]=(br>>24)&0xff;
-    header[32]=2; header[33]=0;
-    header[34]=16; header[35]=0;
-    memcpy(header+36, "data", 4);
-    header[40]= data_bytes & 0xff; header[41]=(data_bytes>>8)&0xff;
-    header[42]=(data_bytes>>16)&0xff; header[43]=(data_bytes>>24)&0xff;
-    if (write(fd, header, 44) != 44) { close(fd); return -1; }
+    SF_INFO info;
+    info.samplerate = sample_rate;
+    info.channels = 1;
+    info.format = SF_FORMAT_WAV | SF_FORMAT_PCM_16;
+    SNDFILE *sf = sf_open(path, SFM_WRITE, &info);
+    if (!sf) return -1;
     for (unsigned i = 0; i < duration_frames; i++) {
         float sample = sinf(2.0f * (float)M_PI * 440.0f * i / sample_rate);
-        int16_t s = (int16_t)(sample * 32767);
-        if (write(fd, &s, 2) != 2) { close(fd); return -1; }
+        sf_writef_float(sf, &sample, 1);
     }
-    close(fd);
+    sf_close(sf);
     return 0;
 }
 
@@ -1062,15 +1045,17 @@ static int test_wav_save(void) {
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         return 1;
     }
-    safe_usleep(800000);
-    /* stop recording (cycle again) */
+    safe_usleep(3000000);   /* record for 3s (ensure enough beep) */
+
+    /* Send second record command to transition RECORD → LOOPING */
     if (send_fifo_command("record 0") != 0) {
         jack_deactivate(client);
         jack_client_close(client);
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         return 1;
     }
-    safe_usleep(500000);
+    safe_usleep(1000000);   /* give time for state change and loop_count to be set */
+
     /* save */
     if (send_fifo_command("save") != 0) {
         jack_deactivate(client);
@@ -1078,16 +1063,28 @@ static int test_wav_save(void) {
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         return 1;
     }
-    safe_usleep(2000000);
-    /* check save.wav */
-    int fd = open("save.wav", O_RDONLY);
-    if (fd < 0) {
+    safe_usleep(8000000);   /* wait for synchronous save to complete (8s) */
+
+    /* check save.wav with retries */
+    int saved = 0;
+    for (int retry = 0; retry < 5; retry++) {
+        int fd = open("save.wav", O_RDONLY);
+        if (fd >= 0) {
+            saved = 1;
+            close(fd);
+            break;
+        }
+        safe_usleep(1000000);
+    }
+    if (!saved) {
         jack_deactivate(client);
         jack_client_close(client);
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         fprintf(stderr, "  FAIL: save.wav not created\n");
         return 1;
     }
+    /* verify header */
+    int fd = open("save.wav", O_RDONLY);
     unsigned char hdr[44];
     if (read(fd, hdr, 44) != 44) {
         close(fd); unlink("save.wav");