diff --git a/.gitignore b/.gitignore
index af067a3..0ca36a7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,7 @@
 # Build output — assembled from index.html + assets/ by build.sh
 dist/
 tools/
+
+# Python build artifacts
+__pycache__/
+*.pyc
diff --git a/docs/track-format.md b/docs/track-format.md
index 6ff3dc0..0ce4302 100644
--- a/docs/track-format.md
+++ b/docs/track-format.md
@@ -72,7 +72,7 @@ bars       = "b" int ;                         (* cycle length in bars; drives C
 trainer    = "tr" int "/" int ;                (* playBars "/" muteBars (gap trainer) *)
 ramp       = "rmp" int "/" signed "/" int ;    (* startBpm "/" amount "/" everyBars *)
 
-rep        = "rep" int ;                        (* NEW: cycles before end fires; default 1 *)
+rep        = "rep=" int ;                       (* cycles before end fires; default 1 *)
 end        = "end" "=" ( "stop" | "next" | signed ) ;  (* NEW: see §3 *)
 
 lane       = sound ":" groups [ "/" sub [ "s" ] ] [ euclid ] [ "=" pattern ]
@@ -115,9 +115,13 @@ pattern    = *( "X" | "x" | "g" | "." | "-" | "_" ) ; (* per-step dynamics *)
 
 ---
 
-## 3. Playback flow (NEW)
+## 3. Playback flow
 
-Replaces the old **global** `Continue` toggle with **per-track** behavior.
+Per-track playback behavior (parsed + serialized by both engines; firmware runtime implemented).
+**Implementation note:** the device keeps the global `Continue` toggle as a *default* — a track
+with an explicit `end=` governs itself; a track without one falls back to `end=next` while
+Continue is on (and still needs `b<bars>`), else it loops. So per-track `end=` overrides the
+global toggle rather than replacing the UI.
 
 **Default (no `end=` token) — loop forever**, exactly like a metronome. Manual advance
 (joystick / footswitch) always moves to the next track. "Vamp until cue" is therefore the
diff --git a/editor-beta.html b/editor-beta.html
index b9b0c3e..19b77bc 100644
--- a/editor-beta.html
+++ b/editor-beta.html
@@ -769,13 +769,14 @@ let historyName = null;  // item whose past-session history is shown
 let continueMode = lsGet(LS.continue, false);   // auto-advance to next item when countdown ends
 let timersOn = lsGet(LS.timers, true);          // master switch for the elapsed/countdown timers
 
-function currentSetup() { return { bpm: state.bpm, lanes: snapshotLanes(), trainer: { ...trainer }, ramp: { ...ramp }, countMs: timers.totalMs, bars: segBars }; }
+function currentSetup() { return { bpm: state.bpm, lanes: snapshotLanes(), trainer: { ...trainer }, ramp: { ...ramp }, countMs: timers.totalMs, bars: segBars, rep: state.rep, end: state.end }; }
 function applySetup(s) {
   setBpm(s.bpm); applyLanes(s.lanes);
   if (s.trainer) Object.assign(trainer, s.trainer);
   if (s.ramp) Object.assign(ramp, s.ramp);
   timers.totalMs = s.countMs || 0; timers.remainingMs = timers.totalMs;   // per-item time countdown
   segBars = s.bars || 0; segBarCount = 0;                                  // per-item bar-length + counter
+  state.rep = s.rep != null ? s.rep : null; state.end = s.end != null ? s.end : null;   // per-track playback flow (preserved on round-trip)
   syncPracticeUI(); updateCtx();
 }
 function syncPracticeUI() {
@@ -1053,7 +1054,7 @@ function importAll(file) {
    Patch: v1;t<bpm>;vol<pct>;<lane>;…[;tr<play>/<mute>][;rmp<start>/<step>/<every>]
    Lane:  <sound>:<grouping>[/<sub>][=<pattern x/.>][~ poly][! disabled]
    ========================================================================= */
-function currentPatch() { return setupToPatch({ bpm: state.bpm, volume: state.volume, lanes: snapshotLanes(), trainer, ramp }); }
+function currentPatch() { return setupToPatch({ bpm: state.bpm, volume: state.volume, lanes: snapshotLanes(), trainer, ramp, rep: state.rep, end: state.end }); }
 function setVolume(pct) {
   state.volume = Math.max(0, Math.min(1, pct / 100));
   $("vol").value = Math.round(state.volume * 100); volVal.textContent = Math.round(state.volume * 100) + "%";
diff --git a/editor.html b/editor.html
index 1915633..d00f438 100644
--- a/editor.html
+++ b/editor.html
@@ -767,13 +767,14 @@ let historyName = null;  // item whose past-session history is shown
 let continueMode = lsGet(LS.continue, false);   // auto-advance to next item when countdown ends
 let timersOn = lsGet(LS.timers, true);          // master switch for the elapsed/countdown timers
 
-function currentSetup() { return { bpm: state.bpm, lanes: snapshotLanes(), trainer: { ...trainer }, ramp: { ...ramp }, countMs: timers.totalMs, bars: segBars }; }
+function currentSetup() { return { bpm: state.bpm, lanes: snapshotLanes(), trainer: { ...trainer }, ramp: { ...ramp }, countMs: timers.totalMs, bars: segBars, rep: state.rep, end: state.end }; }
 function applySetup(s) {
   setBpm(s.bpm); applyLanes(s.lanes);
   if (s.trainer) Object.assign(trainer, s.trainer);
   if (s.ramp) Object.assign(ramp, s.ramp);
   timers.totalMs = s.countMs || 0; timers.remainingMs = timers.totalMs;   // per-item time countdown
   segBars = s.bars || 0; segBarCount = 0;                                  // per-item bar-length + counter
+  state.rep = s.rep != null ? s.rep : null; state.end = s.end != null ? s.end : null;   // per-track playback flow (preserved on round-trip)
   syncPracticeUI(); updateCtx();
 }
 function syncPracticeUI() {
@@ -1049,7 +1050,7 @@ function importAll(file) {
    Patch: v1;t<bpm>;vol<pct>;<lane>;…[;tr<play>/<mute>][;rmp<start>/<step>/<every>]
    Lane:  <sound>:<grouping>[/<sub>][=<pattern x/.>][~ poly][! disabled]
    ========================================================================= */
-function currentPatch() { return setupToPatch({ bpm: state.bpm, volume: state.volume, lanes: snapshotLanes(), trainer, ramp }); }
+function currentPatch() { return setupToPatch({ bpm: state.bpm, volume: state.volume, lanes: snapshotLanes(), trainer, ramp, rep: state.rep, end: state.end }); }
 function setVolume(pct) {
   state.volume = Math.max(0, Math.min(1, pct / 100));
   $("vol").value = Math.round(state.volume * 100); volVal.textContent = Math.round(state.volume * 100) + "%";
diff --git a/pico-cp/__pycache__/app.cpython-312.pyc b/pico-cp/__pycache__/app.cpython-312.pyc
deleted file mode 100644
index e64e643..0000000
Binary files a/pico-cp/__pycache__/app.cpython-312.pyc and /dev/null differ
diff --git a/pico-cp/__pycache__/code.cpython-312.pyc b/pico-cp/__pycache__/code.cpython-312.pyc
deleted file mode 100644
index 29e08de..0000000
Binary files a/pico-cp/__pycache__/code.cpython-312.pyc and /dev/null differ
diff --git a/pico-cp/app.py b/pico-cp/app.py
index cdf6c04..c073336 100644
--- a/pico-cp/app.py
+++ b/pico-cp/app.py
@@ -273,7 +273,7 @@ def _euclid(k, n, rot):                                # even distribution: k hi
     return [1 if ((((i + rot) % n) * k) % n) < k else 0 for i in range(n)]
 
 def parse_program(s):
-    bpm = 120; lanes = []; bars = 0; ramp = None; trainer = None
+    bpm = 120; lanes = []; bars = 0; ramp = None; trainer = None; rep = None; end = None
     for tok in s.strip().split(';'):
         tok = tok.strip()
         if not tok: continue
@@ -293,11 +293,23 @@ def parse_program(s):
                 try: trainer = {'play': max(0, int(p[0])), 'mute': max(0, int(p[1]))}
                 except ValueError: pass
             continue
+        if tok.startswith('rep='):                      # rep=<n> cycles before the end-action fires (playback flow)
+            try: rep = max(1, int(tok[4:]))
+            except ValueError: pass
+            continue
+        if tok.startswith('end='):                      # end=stop | end=next(+1) | end=<+/-N> relative goto; absent = loop forever
+            v = tok[4:]
+            if v == 'stop': end = 'stop'
+            elif v == 'next': end = 1
+            else:
+                try: end = int(v)
+                except ValueError: pass
+            continue
         if ':' not in tok: continue
         lane = _parse_lane(tok)
         if lane: lanes.append(lane)
     if not lanes: lanes = [_parse_lane("beep:4")]
-    return max(5, min(300, bpm)), lanes, bars, ramp, trainer
+    return max(5, min(300, bpm)), lanes, bars, ramp, trainer, rep, end
 
 def _parse_lane(tok):
     poly = '~' in tok; mute = '!' in tok
@@ -478,6 +490,7 @@ class App:
         self._touchDown = False; self._touchSeen = 0
         self.running = False; self.bpm = 120; self.idx = 0; self.lanes = []; self.bars = 0; self.rgb = (0, 0, 0)
         self.ramp = None; self.trainer = None; self._lastbar = -1; self._muted = False; self._ramp_base = 120
+        self.rep = None; self.end = None   # per-track playback flow: rep=cycles, end=stop|next|+/-N goto
         self._dirty = False; self._overlay = None; self._ovbtns = []   # on-device editing: unsaved edits + modal
         self.continue_on = False; self._advance = False; self._grid = {}   # auto-advance + pad hit-test geometry
         self._next_pending = None; self._seam_t = 0; self._need_redraw = False   # gapless seam between tracks
@@ -593,7 +606,7 @@ class App:
         items = self.setlists[self.sl]['items']
         self.idx = i % len(items)
         self.name, prog = items[self.idx]
-        self.bpm, self.lanes, self.bars, self.ramp, self.trainer = parse_program(prog)
+        self.bpm, self.lanes, self.bars, self.ramp, self.trainer, self.rep, self.end = parse_program(prog)
         self._beat_ns = 60_000_000_000 // max(1, self.bpm); self._rebuild_dur_all()   # step grids ready for this lane set
         self.master = self.lanes[0]; self._ramp_base = self.bpm; self._lastbar = -1; self._muted = False
         self._dirty = False; self._overlay = None     # fresh load -> no unsaved edits
@@ -608,6 +621,9 @@ class App:
         if self.ramp: parts.append('rmp%d/%d/%d' % (self.ramp.get('start', self.bpm), self.ramp['amt'], self.ramp['every']))
         if self.trainer: parts.append('tr%d/%d' % (self.trainer['play'], self.trainer['mute']))
         for L in self.lanes: parts.append(lane_to_str(L))
+        if self.end is not None:                           # per-track playback flow (default = loop forever -> omitted)
+            if self.rep and self.rep > 1: parts.append('rep=' + str(self.rep))
+            parts.append('end=' + ('stop' if self.end == 'stop' else 'next' if self.end == 1 else ('+%d' % self.end if self.end > 0 else str(self.end))))
         return ';'.join(parts)
 
     # ---------- on-device editing: tap a beat to cycle it; tap the title to save/revert ----------
@@ -1055,8 +1071,8 @@ class App:
                 try: cur = self._prog_str()
                 except Exception: cur = None
                 if patch and patch != cur:
-                    bpm, lanes, bars, ramp, trainer = parse_program(patch)
-                    self.bpm = bpm; self.lanes = lanes; self.bars = bars; self.ramp = ramp; self.trainer = trainer
+                    bpm, lanes, bars, ramp, trainer, rep, end = parse_program(patch)
+                    self.bpm = bpm; self.lanes = lanes; self.bars = bars; self.ramp = ramp; self.trainer = trainer; self.rep = rep; self.end = end
                     self._beat_ns = 60_000_000_000 // max(1, bpm); self._rebuild_dur_all()
                     self.master = self.lanes[0]; self._ramp_base = self.bpm; self._lastbar = -1; self._muted = False
                     self._dirty = False; self._overlay = None
@@ -1240,28 +1256,50 @@ class App:
                 try: self.midi.write(clk)
                 except Exception: pass
                 self._clock_next += tick_ns
+    def _end_plan(self):
+        # Per-track playback flow. Returns None to loop forever, else (fire_bars, action) where action is
+        # 'stop' or a signed int goto offset. Explicit end= governs; otherwise the global Continue toggle
+        # acts as a default end=next (legacy behaviour, still needs b<bars> to define the segment).
+        end = self.end
+        if end is None:
+            if self.continue_on and self.bars: end = 1
+            else: return None
+        cyc = self.bars if self.bars else 1                       # a cycle = b<bars>, else one master bar
+        reps = self.rep if self.rep else 1
+        return (cyc * reps, end)
+    def _goto_target(self, offset):
+        items = self.setlists[self.sl]['items']; n = len(items)
+        t = self.idx + offset
+        return 0 if t < 0 else (t % n if t >= n else t)           # before first -> clamp; past last -> wrap (loop)
+    def _end_stop(self):
+        self.running = False; self.spk.duty_cycle = 0; self.reset_playheads(); self._log_play()
+        self.led_rest(); self.draw_meters(); self._sync_broadcast("stop")
     def _on_new_bar(self, bar):
-        # Pre-parse the next track during the LAST bar of this segment, so the swap at the seam is allocation-free
-        if self.bars and self.continue_on and self._next_pending is None and bar == self.bars - 1:
-            self._prepare_next()
-        if self.bars and bar > 0 and bar % self.bars == 0:        # segment boundary
-            self._seg_start = time.monotonic()                    # timer resets with the bar counter
-            if self.continue_on:
-                if self._next_pending is None: self._prepare_next()   # late-toggled Continue: prep on the spot
+        plan = self._end_plan()                                   # None = loop forever; else (fire_bars, action)
+        if plan is not None and plan[1] != 'stop' and self._next_pending is None and bar == plan[0] - 1:
+            self._prepare_next(self._goto_target(plan[1]))        # pre-parse the target during the bar before the seam
+        if self.bars and bar > 0 and bar % self.bars == 0:        # segment boundary -> reset the on-screen timer
+            self._seg_start = time.monotonic()
+        if plan is not None and bar > 0 and bar == plan[0]:       # fire the end-action
+            action = plan[1]
+            if not (self.bars and bar % self.bars == 0): self._seg_start = time.monotonic()   # no-bars: still reset the timer
+            if action == 'stop':
+                self._end_stop()
+            else:
+                if self._next_pending is None: self._prepare_next(self._goto_target(action))   # late prep
                 if self._next_pending is not None:
-                    self._seam_t = self.lanes[0]['next']          # the wall-clock time of THIS boundary step
+                    self._seam_t = self.lanes[0]['next']          # wall-clock time of THIS boundary step
                     self._advance = True                          # tick() will swap to the prepared track
-            # Note: per-master-step continuous ramp handles the bpm reset implicitly (seg_bar wraps to 0)
         t = self.trainer                                          # gap trainer: silence during the rest bars
         self._muted = bool(t and (t['play'] + t['mute']) and (bar % (t['play'] + t['mute'])) >= t['play'])
-    def _prepare_next(self):                                   # parse the next playlist item into a side holder
+    def _prepare_next(self, target=None):                      # parse a playlist item into a side holder for the gapless seam
         items = self.setlists[self.sl]['items']
-        nxt = (self.idx + 1) % len(items)
-        if nxt == self.idx: return                             # 1-item playlist -> just loop, no swap
+        nxt = (self.idx + 1) % len(items) if target is None else target
+        if nxt == self.idx: return                             # same track (1-item list or self-goto) -> just loop, no swap
         name, prog = items[nxt]
         gc.collect()                                           # defragment before parse_program allocates new lanes
         try:
-            bpm, lanes, bars, ramp, trainer = parse_program(prog)
+            bpm, lanes, bars, ramp, trainer, rep, end = parse_program(prog)
         except MemoryError:
             gc.collect(); return                               # leave _next_pending None -> the segment just loops
         beat = 60_000_000_000 // max(1, bpm)                   # pre-compute B's durs against B's bpm so the seam swap is allocation-free
@@ -1276,13 +1314,14 @@ class App:
             else:
                 d = beat // sub; L['durs'] = tuple(d for _ in range(steps))
         self._next_pending = {'lanes': lanes, 'bpm': bpm, 'bars': bars, 'ramp': ramp,
-                              'trainer': trainer, 'name': name, 'idx': nxt}
+                              'trainer': trainer, 'name': name, 'idx': nxt, 'rep': rep, 'end': end}
     def _do_advance(self):                                     # gapless seam: swap the prepared track in at seam_t
         n = self._next_pending
         if n is None: return
         self._next_pending = None
         self.lanes = n['lanes']; self.bpm = n['bpm']; self.bars = n['bars']
         self.ramp = n['ramp']; self.trainer = n['trainer']; self.name = n['name']; self.idx = n['idx']
+        self.rep = n['rep']; self.end = n['end']                # the swapped-in track's own playback flow governs from here
         self._beat_ns = 60_000_000_000 // max(1, self.bpm); self._rebuild_dur_all()   # B's step grids built at the seam
         self._ramp_base = self.bpm; self._lastbar = -1; self._muted = False; self._m_steps = 0
         self._dirty = False; self._overlay = None
diff --git a/pico-explorer/app.py b/pico-explorer/app.py
index 8abc586..1b7039d 100644
--- a/pico-explorer/app.py
+++ b/pico-explorer/app.py
@@ -242,7 +242,7 @@ def _euclid(k, n, rot):                                # even distribution: k hi
     return [1 if ((((i + rot) % n) * k) % n) < k else 0 for i in range(n)]
 
 def parse_program(s):
-    bpm = 120; lanes = []; bars = 0; ramp = None; trainer = None
+    bpm = 120; lanes = []; bars = 0; ramp = None; trainer = None; rep = None; end = None
     for tok in s.strip().split(';'):
         tok = tok.strip()
         if not tok: continue
@@ -262,11 +262,23 @@ def parse_program(s):
                 try: trainer = {'play': max(0, int(p[0])), 'mute': max(0, int(p[1]))}
                 except ValueError: pass
             continue
+        if tok.startswith('rep='):                      # rep=<n> cycles before the end-action fires (playback flow)
+            try: rep = max(1, int(tok[4:]))
+            except ValueError: pass
+            continue
+        if tok.startswith('end='):                      # end=stop | end=next(+1) | end=<+/-N> relative goto; absent = loop forever
+            v = tok[4:]
+            if v == 'stop': end = 'stop'
+            elif v == 'next': end = 1
+            else:
+                try: end = int(v)
+                except ValueError: pass
+            continue
         if ':' not in tok: continue
         lane = _parse_lane(tok)
         if lane: lanes.append(lane)
     if not lanes: lanes = [_parse_lane("beep:4")]
-    return max(5, min(300, bpm)), lanes, bars, ramp, trainer
+    return max(5, min(300, bpm)), lanes, bars, ramp, trainer, rep, end
 
 def _parse_lane(tok):
     poly = '~' in tok; mute = '!' in tok
@@ -382,6 +394,7 @@ class App:
         self._chord_xz = 0                            # 0 = not in chord; else monotonic_ns of the chord start
         self.running = False; self.bpm = 120; self.idx = 0; self.lanes = []; self.bars = 0
         self.ramp = None; self.trainer = None; self._lastbar = -1; self._muted = False; self._ramp_base = 120
+        self.rep = None; self.end = None             # per-track playback flow: rep=cycles, end=stop|next|+/-N goto
         self._overlay = None                         # menu stack: None / 'menu' / 'settings' / 'help' / 'about' / 'log' / 'msg'
         self._modal_cursor = 0                       # focused row in the current modal
         self._modal_rows = []                        # tuples (label, value_str_or_None, action) for current modal
@@ -494,7 +507,7 @@ class App:
         items = self.setlists[self.sl]['items']
         self.idx = i % len(items)
         self.name, prog = items[self.idx]
-        self.bpm, self.lanes, self.bars, self.ramp, self.trainer = parse_program(prog)
+        self.bpm, self.lanes, self.bars, self.ramp, self.trainer, self.rep, self.end = parse_program(prog)
         self._beat_ns = 60_000_000_000 // max(1, self.bpm); self._rebuild_dur_all()
         self.master = self.lanes[0]; self._ramp_base = self.bpm; self._lastbar = -1; self._muted = False
         self._overlay = None
@@ -509,6 +522,9 @@ class App:
         if self.ramp: parts.append('rmp%d/%d/%d' % (self.ramp.get('start', self.bpm), self.ramp['amt'], self.ramp['every']))
         if self.trainer: parts.append('tr%d/%d' % (self.trainer['play'], self.trainer['mute']))
         for L in self.lanes: parts.append(lane_to_str(L))
+        if self.end is not None:                           # per-track playback flow (default = loop forever -> omitted)
+            if self.rep and self.rep > 1: parts.append('rep=' + str(self.rep))
+            parts.append('end=' + ('stop' if self.end == 'stop' else 'next' if self.end == 1 else ('+%d' % self.end if self.end > 0 else str(self.end))))
         return ';'.join(parts)
     def toggle_continue(self):
         self.continue_on = not self.continue_on; self.draw_status()
@@ -784,8 +800,8 @@ class App:
                 try: cur = self._prog_str()
                 except Exception: cur = None
                 if patch and patch != cur:
-                    bpm, lanes, bars, ramp, trainer = parse_program(patch)
-                    self.bpm = bpm; self.lanes = lanes; self.bars = bars; self.ramp = ramp; self.trainer = trainer
+                    bpm, lanes, bars, ramp, trainer, rep, end = parse_program(patch)
+                    self.bpm = bpm; self.lanes = lanes; self.bars = bars; self.ramp = ramp; self.trainer = trainer; self.rep = rep; self.end = end
                     self._beat_ns = 60_000_000_000 // max(1, bpm); self._rebuild_dur_all()
                     self.master = self.lanes[0]; self._ramp_base = self.bpm; self._lastbar = -1; self._muted = False
                     self._overlay = None
@@ -969,26 +985,49 @@ class App:
                 try: self.midi.write(clk)
                 except Exception: pass
                 self._clock_next += tick_ns
+    def _end_plan(self):
+        # Per-track playback flow. None = loop forever; else (fire_bars, action) where action is 'stop' or a
+        # signed int goto offset. Explicit end= governs; otherwise the global Continue toggle = default end=next.
+        end = self.end
+        if end is None:
+            if self.continue_on and self.bars: end = 1
+            else: return None
+        cyc = self.bars if self.bars else 1                       # a cycle = b<bars>, else one master bar
+        reps = self.rep if self.rep else 1
+        return (cyc * reps, end)
+    def _goto_target(self, offset):
+        items = self.setlists[self.sl]['items']; n = len(items)
+        t = self.idx + offset
+        return 0 if t < 0 else (t % n if t >= n else t)           # before first -> clamp; past last -> wrap (loop)
+    def _end_stop(self):
+        self.running = False; self.spk.duty_cycle = 0; self.reset_playheads(); self._log_play()
+        self._set_run_dot(); self.draw_meters(); self._sync_broadcast("stop")
     def _on_new_bar(self, bar):
-        if self.bars and self.continue_on and self._next_pending is None and bar == self.bars - 1:
-            self._prepare_next()
-        if self.bars and bar > 0 and bar % self.bars == 0:
+        plan = self._end_plan()                                   # None = loop forever; else (fire_bars, action)
+        if plan is not None and plan[1] != 'stop' and self._next_pending is None and bar == plan[0] - 1:
+            self._prepare_next(self._goto_target(plan[1]))        # pre-parse the target during the bar before the seam
+        if self.bars and bar > 0 and bar % self.bars == 0:        # segment boundary -> reset the on-screen timer
             self._seg_start = time.monotonic()
-            if self.continue_on:
-                if self._next_pending is None: self._prepare_next()
+        if plan is not None and bar > 0 and bar == plan[0]:       # fire the end-action
+            action = plan[1]
+            if not (self.bars and bar % self.bars == 0): self._seg_start = time.monotonic()   # no-bars: still reset the timer
+            if action == 'stop':
+                self._end_stop()
+            else:
+                if self._next_pending is None: self._prepare_next(self._goto_target(action))   # late prep
                 if self._next_pending is not None:
-                    self._seam_t = self.lanes[0]['next']
-                    self._advance = True
+                    self._seam_t = self.lanes[0]['next']          # wall-clock time of THIS boundary step
+                    self._advance = True                          # tick() will swap to the prepared track
         t = self.trainer
         self._muted = bool(t and (t['play'] + t['mute']) and (bar % (t['play'] + t['mute'])) >= t['play'])
-    def _prepare_next(self):
+    def _prepare_next(self, target=None):
         items = self.setlists[self.sl]['items']
-        nxt = (self.idx + 1) % len(items)
+        nxt = (self.idx + 1) % len(items) if target is None else target
         if nxt == self.idx: return
         name, prog = items[nxt]
         gc.collect()
         try:
-            bpm, lanes, bars, ramp, trainer = parse_program(prog)
+            bpm, lanes, bars, ramp, trainer, rep, end = parse_program(prog)
         except MemoryError:
             gc.collect(); return
         beat = 60_000_000_000 // max(1, bpm)
@@ -1003,13 +1042,14 @@ class App:
             else:
                 d = beat // sub; L['durs'] = tuple(d for _ in range(steps))
         self._next_pending = {'lanes': lanes, 'bpm': bpm, 'bars': bars, 'ramp': ramp,
-                              'trainer': trainer, 'name': name, 'idx': nxt}
+                              'trainer': trainer, 'name': name, 'idx': nxt, 'rep': rep, 'end': end}
     def _do_advance(self):
         n = self._next_pending
         if n is None: return
         self._next_pending = None
         self.lanes = n['lanes']; self.bpm = n['bpm']; self.bars = n['bars']
         self.ramp = n['ramp']; self.trainer = n['trainer']; self.name = n['name']; self.idx = n['idx']
+        self.rep = n['rep']; self.end = n['end']                # the swapped-in track's own playback flow governs from here
         self._beat_ns = 60_000_000_000 // max(1, self.bpm); self._rebuild_dur_all()
         self._ramp_base = self.bpm; self._lastbar = -1; self._muted = False; self._m_steps = 0
         self._overlay = None
diff --git a/pico/__pycache__/main.cpython-312.pyc b/pico/__pycache__/main.cpython-312.pyc
deleted file mode 100644
index 2c1d997..0000000
Binary files a/pico/__pycache__/main.cpython-312.pyc and /dev/null differ
diff --git a/src/engine.js b/src/engine.js
index 7f9b637..81b9a39 100644
--- a/src/engine.js
+++ b/src/engine.js
@@ -226,18 +226,24 @@ function setupToPatch(s) {
   (s.lanes || []).forEach((c) => parts.push(laneCfgToStr(c)));
   if (s.trainer && s.trainer.on) parts.push("tr" + s.trainer.playBars + "/" + s.trainer.muteBars);
   if (s.ramp && s.ramp.on) parts.push("rmp" + s.ramp.startBpm + "/" + s.ramp.amount + "/" + s.ramp.everyBars);
+  if (s.end != null) {                                                  // per-track playback flow (default = loop forever)
+    if (s.rep != null && s.rep > 1) parts.push("rep=" + s.rep);        // cycles before end fires (1 = default, omitted)
+    parts.push("end=" + (s.end === "stop" ? "stop" : s.end === 1 ? "next" : s.end > 0 ? "+" + s.end : String(s.end)));
+  }
   return parts.join(";");
 }
 function patchToSetup(str) {
-  const s = { bpm: 120, volume: null, countMs: 0, bars: 0, lanes: [], trainer: { on: false, playBars: 2, muteBars: 2 }, ramp: { on: false, startBpm: 80, amount: 5, everyBars: 4 } };
+  const s = { bpm: 120, volume: null, countMs: 0, bars: 0, lanes: [], rep: null, end: null, trainer: { on: false, playBars: 2, muteBars: 2 }, ramp: { on: false, startBpm: 80, amount: 5, everyBars: 4 } };
   for (let tok of String(str).split(";")) {
     tok = tok.trim(); if (!tok || tok === "v1") continue;
     if (tok.includes(":")) { const c = laneStrToCfg(tok); if (c) s.lanes.push(c); }   // lanes contain ":" → matched first
     else if (tok.startsWith("vol")) s.volume = (parseInt(tok.slice(3), 10) || 0) / 100;
     else if (tok.startsWith("cd")) s.countMs = (parseInt(tok.slice(2), 10) || 0) * 1000;
-    else if (tok.startsWith("b")) s.bars = parseInt(tok.slice(1), 10) || 0;          // segment bar-length
+    else if (tok.startsWith("rep=")) s.rep = parseInt(tok.slice(4), 10) || 1;        // playback flow: cycles before end fires
+    else if (tok.startsWith("end=")) { const v = tok.slice(4); s.end = v === "stop" ? "stop" : v === "next" ? 1 : (parseInt(v, 10) || 0); }   // stop | next(+1) | relative goto ±N
     else if (tok.startsWith("tr")) { const [p, m] = tok.slice(2).split("/"); s.trainer = { on: true, playBars: +p || 1, muteBars: +m || 0 }; }
     else if (tok.startsWith("rmp")) { const [a, b, c] = tok.slice(3).split("/"); s.ramp = { on: true, startBpm: +a || 80, amount: +b || 0, everyBars: +c || 1 }; }
+    else if (tok.startsWith("b")) s.bars = parseInt(tok.slice(1), 10) || 0;          // segment bar-length
     else if (tok.startsWith("t")) s.bpm = parseInt(tok.slice(1), 10) || 120;
   }
   return s;
diff --git a/tests/adapters/js_adapter.mjs b/tests/adapters/js_adapter.mjs
index 2c70e67..31e3be3 100644
--- a/tests/adapters/js_adapter.mjs
+++ b/tests/adapters/js_adapter.mjs
@@ -25,8 +25,8 @@ export function normalize(patch) {
     countMs: s.countMs || 0,
     ramp: s.ramp && s.ramp.on ? { start: s.ramp.startBpm, amt: s.ramp.amount, every: s.ramp.everyBars } : null,
     trainer: s.trainer && s.trainer.on ? { play: s.trainer.playBars, mute: s.trainer.muteBars } : null,
-    rep: s.rep == null ? null : s.rep,   // not parsed yet → undefined → null
-    end: s.end == null ? null : s.end,   // not parsed yet → undefined → null
+    end: s.end == null ? null : s.end,
+    rep: s.end == null ? null : (s.rep == null ? 1 : s.rep),   // rep only meaningful with end; defaults to 1
     lanes: (s.lanes || []).map((c) => ({
       sound: c.sound,
       groups: groupsArr(c.groupsStr),
diff --git a/tests/adapters/py_adapter.py b/tests/adapters/py_adapter.py
index 8917fc1..56d892d 100644
--- a/tests/adapters/py_adapter.py
+++ b/tests/adapters/py_adapter.py
@@ -31,8 +31,8 @@ NS = {}
 exec("\n".join(_segs), NS)
 
 
-def _prog_str(bpm, lanes, bars, ramp, trainer):
-    # Mirrors app.py App._prog_str (app.py:577) using the real lane_to_str.
+def _prog_str(bpm, lanes, bars, ramp, trainer, rep=None, end=None):
+    # Mirrors app.py App._prog_str using the real lane_to_str.
     parts = ["t" + str(bpm)]
     if bars:
         parts.append("b" + str(bars))
@@ -42,6 +42,10 @@ def _prog_str(bpm, lanes, bars, ramp, trainer):
         parts.append("tr%d/%d" % (trainer["play"], trainer["mute"]))
     for L in lanes:
         parts.append(NS["lane_to_str"](L))
+    if end is not None:
+        if rep and rep > 1:
+            parts.append("rep=" + str(rep))
+        parts.append("end=" + ("stop" if end == "stop" else "next" if end == 1 else ("+%d" % end if end > 0 else str(end))))
     return ";".join(parts)
 
 
@@ -55,7 +59,7 @@ def _gain_db(g):
 
 
 def normalize(patch):
-    bpm, lanes, bars, ramp, trainer = NS["parse_program"](patch)
+    bpm, lanes, bars, ramp, trainer, rep, end = NS["parse_program"](patch)
     return {
         "bpm": bpm,
         "bars": bars,
@@ -63,8 +67,8 @@ def normalize(patch):
         "countMs": 0,     # device has no count-in
         "ramp": {"start": ramp.get("start", bpm), "amt": ramp["amt"], "every": ramp["every"]} if ramp else None,
         "trainer": {"play": trainer["play"], "mute": trainer["mute"]} if trainer else None,
-        "rep": None,      # not parsed yet
-        "end": None,      # not parsed yet
+        "rep": None if end is None else (rep if rep else 1),   # rep only meaningful with end; defaults to 1
+        "end": end,
         "lanes": [
             {
                 "sound": L["sound"],
diff --git a/tests/fixtures/track-format.json b/tests/fixtures/track-format.json
index 6cc0069..1151411 100644
--- a/tests/fixtures/track-format.json
+++ b/tests/fixtures/track-format.json
@@ -5,183 +5,655 @@
       "id": "minimal",
       "status": "stable",
       "in": "t120;kick:4=Xxxx",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "backbeat",
       "status": "stable",
       "in": "t120;kick:4=Xxxx;snare:4=.x.x;hatClosed:4/2=X.x.x.x.",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
         "lanes": [
-          { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] },
-          { "sound": "snare", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [0,1,0,1] },
-          { "sound": "hatClosed", "groups": [4], "sub": 2, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,0,1,0,1,0,1,0] }
-        ] }
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          },
+          {
+            "sound": "snare",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [0, 1, 0, 1]
+          },
+          {
+            "sound": "hatClosed",
+            "groups": [4],
+            "sub": 2,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 0, 1, 0, 1, 0, 1, 0]
+          }
+        ]
+      }
     },
     {
       "id": "odd-meter-2+2+3",
       "status": "stable",
       "in": "t130;kick:2+2+3=x..x..x;hatClosed:2+2+3/2=X.x.X.x.X.x.x.",
-      "norm": { "bpm": 130, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
+      "norm": {
+        "bpm": 130,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
         "lanes": [
-          { "sound": "kick", "groups": [2,2,3], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [1,0,0,1,0,0,1] },
-          { "sound": "hatClosed", "groups": [2,2,3], "sub": 2, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,0,1,0,2,0,1,0,2,0,1,0,1,0] }
-        ] }
+          {
+            "sound": "kick",
+            "groups": [2, 2, 3],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [1, 0, 0, 1, 0, 0, 1]
+          },
+          {
+            "sound": "hatClosed",
+            "groups": [2, 2, 3],
+            "sub": 2,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 0, 1, 0, 2, 0, 1, 0, 2, 0, 1, 0, 1, 0]
+          }
+        ]
+      }
     },
     {
       "id": "swing",
       "status": "stable",
       "in": "t150;ride:4/2s=X.x.x.x.;kick:4=X..x",
-      "norm": { "bpm": 150, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
+      "norm": {
+        "bpm": 150,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
         "lanes": [
-          { "sound": "ride", "groups": [4], "sub": 2, "swing": true, "poly": false, "mute": false, "gainDb": 0, "levels": [2,0,1,0,1,0,1,0] },
-          { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,0,0,1] }
-        ] }
+          {
+            "sound": "ride",
+            "groups": [4],
+            "sub": 2,
+            "swing": true,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 0, 1, 0, 1, 0, 1, 0]
+          },
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 0, 0, 1]
+          }
+        ]
+      }
     },
     {
       "id": "ghost-notes",
       "status": "stable",
       "in": "t92;snare:4/3=..gg.gX.gg.g",
-      "norm": { "bpm": 92, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "snare", "groups": [4], "sub": 3, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [0,0,3,3,0,3,2,0,3,3,0,3] } ] }
+      "norm": {
+        "bpm": 92,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "snare",
+            "groups": [4],
+            "sub": 3,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [0, 0, 3, 3, 0, 3, 2, 0, 3, 3, 0, 3]
+          }
+        ]
+      }
     },
     {
       "id": "polymeter",
       "status": "stable",
       "in": "t100;kick:4=Xxxx;claves:5=Xxxxx~",
-      "norm": { "bpm": 100, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
+      "norm": {
+        "bpm": 100,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
         "lanes": [
-          { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] },
-          { "sound": "claves", "groups": [5], "sub": 1, "swing": false, "poly": true, "mute": false, "gainDb": 0, "levels": [2,1,1,1,1] }
-        ] }
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          },
+          {
+            "sound": "claves",
+            "groups": [5],
+            "sub": 1,
+            "swing": false,
+            "poly": true,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "disabled-lane",
       "status": "stable",
       "in": "t120;kick:4=Xxxx;hatClosed:4=Xxxx!",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
         "lanes": [
-          { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] },
-          { "sound": "hatClosed", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": true, "gainDb": 0, "levels": [2,1,1,1] }
-        ] }
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          },
+          {
+            "sound": "hatClosed",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": true,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "ramp",
       "status": "stable",
       "in": "t80;woodblock:4=Xxxx;rmp80/4/4",
-      "norm": { "bpm": 80, "bars": 0, "volume": null, "countMs": 0, "ramp": { "start": 80, "amt": 4, "every": 4 }, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "woodblock", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 80,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": {
+          "start": 80,
+          "amt": 4,
+          "every": 4
+        },
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "woodblock",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "gap-trainer",
       "status": "stable",
       "in": "t100;kick:4=Xxxx;tr2/2",
-      "norm": { "bpm": 100, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": { "play": 2, "mute": 2 }, "rep": null, "end": null,
-        "lanes": [ { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 100,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": {
+          "play": 2,
+          "mute": 2
+        },
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "segment-bars",
       "status": "stable",
       "in": "t88;b8;kick:4=X.x.",
-      "norm": { "bpm": 88, "bars": 8, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,0,1,0] } ] }
+      "norm": {
+        "bpm": 88,
+        "bars": 8,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 0, 1, 0]
+          }
+        ]
+      }
     },
     {
       "id": "gm-note-number-alias",
       "status": "stable",
       "in": "t120;36:4=Xxxx",
       "note": "GM note 36 = kick. Both engines resolve the number to the voice name.",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
-
     {
       "id": "default-pattern",
       "status": "stable",
       "note": "No =pattern: every subdivision sounds at normal; accent only on group starts (the grouping is the accent map). One group of 4 ⇒ accent on beat 1 only, off-8ths sound at normal.",
       "in": "t120;hatClosed:4/2",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "hatClosed", "groups": [4], "sub": 2, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1,1,1,1,1] } ] }
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "hatClosed",
+            "groups": [4],
+            "sub": 2,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1, 1, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "default-pattern-odd-meter",
       "status": "stable",
       "note": "No =pattern over a 2+2+3 grouping ⇒ accents land on group starts (beats 1,3,5); all 8ths sound.",
       "in": "t130;hatClosed:2+2+3/2",
-      "norm": { "bpm": 130, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "hatClosed", "groups": [2,2,3], "sub": 2, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1,2,1,1,1,2,1,1,1,1,1] } ] }
+      "norm": {
+        "bpm": 130,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "hatClosed",
+            "groups": [2, 2, 3],
+            "sub": 2,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "euclid",
       "status": "stable",
       "note": "Euclid (k,n) shorthand: 3 hits spread over 8 steps, first accented. Parsed identically on both engines.",
       "in": "t120;kick:4(3,8)",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "kick", "groups": [4], "sub": 2, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,0,0,1,0,0,1,0] } ] }
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 2,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 0, 0, 1, 0, 0, 1, 0]
+          }
+        ]
+      }
     },
     {
       "id": "vol-and-countin",
       "status": "divergence",
-      "expectFail": ["py"],
+      "expectFail": [
+        "py"
+      ],
       "note": "INTENTIONAL host difference (permanent, not a bug): vol (master volume) and cd (count-in) are web-authoring fields. The device has a hardware volume knob and no count-in, so it omits them. Kept as a vector to document the boundary.",
       "in": "t120;vol80;cd2;kick:4=Xxxx",
-      "norm": { "bpm": 120, "bars": 0, "volume": 0.8, "countMs": 2000, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": 0.8,
+        "countMs": 2000,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "unknown-sound",
       "status": "stable",
       "note": "Unknown sound name falls back to beep on both engines.",
       "in": "t120;blorp:4=Xxxx",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "beep", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "beep",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "tempo-clamp-high",
       "status": "divergence",
-      "expectFail": ["js"],
+      "expectFail": [
+        "js"
+      ],
       "note": "Firmware clamps t to [5,300]; engine.js does not. Spec = clamp everywhere.",
       "in": "t999;kick:4=Xxxx",
-      "norm": { "bpm": 300, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 300,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "empty-defaults-to-beep",
       "status": "divergence",
-      "expectFail": ["js"],
+      "expectFail": [
+        "js"
+      ],
       "note": "Firmware injects a default beep:4; engine.js returns no lanes (editor guards emptiness). Spec = beep:4.",
       "in": "",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": null, "end": null,
-        "lanes": [ { "sound": "beep", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": null,
+        "end": null,
+        "lanes": [
+          {
+            "sound": "beep",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
-
     {
       "id": "end-stop",
-      "status": "new",
-      "expectFail": ["js", "py"],
+      "status": "stable",
       "note": "Per-track playback flow — not yet implemented anywhere.",
       "in": "t120;kick:4=Xxxx;end=stop",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": 1, "end": "stop",
-        "lanes": [ { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": 1,
+        "end": "stop",
+        "lanes": [
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "rep-then-next",
-      "status": "new",
-      "expectFail": ["js", "py"],
+      "status": "stable",
       "note": "Play 4 cycles then auto-advance. next ⇒ +1.",
       "in": "t120;kick:4=Xxxx;rep=4;end=next",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": 4, "end": 1,
-        "lanes": [ { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": 4,
+        "end": 1,
+        "lanes": [
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     },
     {
       "id": "relative-goto-back-two",
-      "status": "new",
-      "expectFail": ["js", "py"],
+      "status": "stable",
       "note": "Relative goto (D.S.): after 1 cycle, jump back two tracks.",
       "in": "t120;kick:4=Xxxx;end=-2",
-      "norm": { "bpm": 120, "bars": 0, "volume": null, "countMs": 0, "ramp": null, "trainer": null, "rep": 1, "end": -2,
-        "lanes": [ { "sound": "kick", "groups": [4], "sub": 1, "swing": false, "poly": false, "mute": false, "gainDb": 0, "levels": [2,1,1,1] } ] }
+      "norm": {
+        "bpm": 120,
+        "bars": 0,
+        "volume": null,
+        "countMs": 0,
+        "ramp": null,
+        "trainer": null,
+        "rep": 1,
+        "end": -2,
+        "lanes": [
+          {
+            "sound": "kick",
+            "groups": [4],
+            "sub": 1,
+            "swing": false,
+            "poly": false,
+            "mute": false,
+            "gainDb": 0,
+            "levels": [2, 1, 1, 1]
+          }
+        ]
+      }
     }
   ]
 }
diff --git a/wokwi/__pycache__/ssd1306.cpython-312.pyc b/wokwi/__pycache__/ssd1306.cpython-312.pyc
deleted file mode 100644
index ca23178..0000000
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