fix(claude): detect rolling 5h session window from actual usage

The fixed 03:00 UTC grid (5 slots of 5/5/5/5/4h) did not match Claude's real
rate-limit behavior: each 5h window starts at the first message after a ≥5h
gap, not at a clock boundary. Detect the window start dynamically by walking
buffered usage events and fall back to the fixed grid only when there is no
activity in the last 5h. Payload now exposes start_ts and source ("rolling"
vs "fixed") alongside the existing end_ts.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: postadelmaga

ohmytoken/contents/code/local_stats.py

@@ -52,6 +52,7 @@
 month_ts = (local_midnight - timedelta(days=30)).timestamp() * 1000
 
 WINDOW_HOURS = [5, 5, 5, 5, 4]
+WINDOW_DURATION_MS = 5 * 3600 * 1000
 window_boundaries = []
 cum_h = 0
 for wh in WINDOW_HOURS:
@@ -66,9 +67,17 @@
         current_window_idx = i
         break
 
+# Fallback (fixed grid) — overridden below once we've seen real activity.
 cur_win_start = window_boundaries[current_window_idx][0]
 cur_win_end = window_boundaries[current_window_idx][1]
 
+# Buffer for rolling-window detection: Claude's real 5h rate-limit window
+# starts from the first message after a ≥5h gap, not from a fixed clock grid.
+# We keep ~6h of events so we can reconstruct the current window start from data.
+_WINDOW_BUFFER_MS = WINDOW_DURATION_MS + 3600 * 1000
+window_event_cutoff_ts = now_ms - _WINDOW_BUFFER_MS
+window_events = []  # [(ts_ms, inp, out, cr, cc)]
+
 # --- Credentials & tier ---
 sub_type = "unknown"
 tier = "unknown"
@@ -174,9 +183,10 @@ def add_tokens_by_ts(ts_ms, inp, out, cr, cc):
                 tok_today["cache_read"] += cr; tok_today["cache_create"] += cc
     tok_total["input"] += inp; tok_total["output"] += out
     tok_total["cache_read"] += cr; tok_total["cache_create"] += cc
-    # Session window
-    if cur_win_start <= ts_ms < cur_win_end:
-        win_input += total_in; win_output += out
+    # Session window: buffer events; computed after full scan so we can align
+    # to the real rolling 5h window (first-message-after-gap), not a fixed grid.
+    if ts_ms >= window_event_cutoff_ts:
+        window_events.append((ts_ms, inp, out, cr, cc))
     # Rate tracking — keep components separate for per-type rates
     if ts_ms >= rate_cutoff_ts:
         recent_events.append((ts_ms, inp, out, cr, cc))
@@ -561,6 +571,36 @@ def calc_rate(window_ms, extract_fn):
     rate_output_5m = rate_output_30m = 0.0
     rate_all_5m = rate_all_30m = 0.0
 
+# --- Rolling session window detection ---
+# Walk events ascending; a new window starts whenever an event arrives ≥5h
+# after the previous window start. The last computed start is the current one
+# if it hasn't expired yet; otherwise fall back to the fixed clock grid.
+window_source = "fixed"
+if window_events:
+    window_events.sort(key=lambda e: e[0])
+    ws_roll = window_events[0][0]
+    for ev in window_events:
+        if ev[0] >= ws_roll + WINDOW_DURATION_MS:
+            ws_roll = ev[0]
+    we_roll = ws_roll + WINDOW_DURATION_MS
+    if we_roll > now_ms:
+        cur_win_start = ws_roll
+        cur_win_end = we_roll
+        window_source = "rolling"
+        # Realign window slot index to whichever fixed slot contains the
+        # detected start (keeps the "N/5" indicator meaningful).
+        for i, (ws_fb, we_fb) in enumerate(window_boundaries):
+            if ws_fb <= ws_roll < we_fb:
+                current_window_idx = i
+                break
+
+win_input = 0
+win_output = 0
+for ts, inp, out, cr, cc in window_events:
+    if cur_win_start <= ts < cur_win_end:
+        win_input += inp + cr + cc
+        win_output += out
+
 print(json.dumps({
     "subscription": {"type": sub_type, "tier": tier},
     "limits": limits,
@@ -570,7 +610,9 @@ def calc_rate(window_ms, extract_fn):
     "est_cost": {"today": round(cost_today, 4), "week": round(cost_week, 4), "total": round(cost_total, 4)},
     "session_window": {
         "number": current_window_idx + 1, "total": len(WINDOW_HOURS),
+        "start_ts": int(cur_win_start),
         "end_ts": int(cur_win_end),
+        "source": window_source,
         "input_limit": daily_in // 5, "output_limit": daily_out // 5,
         "input_used": win_input, "output_used": win_output,
     },