diff --git a/collatz.py b/collatz.py
new file mode 100644
index 0000000..aef01a1
--- /dev/null
+++ b/collatz.py
@@ -0,0 +1,211 @@
+#!/usr/bin/env python3
+import curses
+import time
+import os
+from pathlib import Path
+from mathstream import StreamNumber, add, mul, div, is_even, clear_logs
+
+
+LOG_DIR = Path("instance/log")
+
+
+def collatz_step(n, three, two, one):
+    return div(n, two) if is_even(n) else add(mul(n, three), one)
+
+
+def draw_header(win, step, elapsed, avg_step, digits_len):
+    """Render header above graph and panels."""
+    win.erase()
+    cols = curses.COLS - 1
+    bar = "─" * cols
+    lines = [
+        f" Collatz (3n + 1) Streamed Viewer ",
+        f" Step: {step}",
+        f" Elapsed: {elapsed:8.2f}s | Avg/Step: {avg_step:8.5f}s",
+        f" Digits: {digits_len:,} | ↑↓ scroll number | PgUp/PgDn scroll log | q quit",
+    ]
+    for i, line in enumerate(lines):
+        win.addstr(i, 0, line[:cols], curses.color_pair(1))
+    win.addstr(len(lines), 0, bar, curses.color_pair(2))
+    win.noutrefresh()
+
+
+def draw_graph(win, graph_buf, direction_up, width):
+    """Render a single-line graph: grey ░ for empty, colored █ for data."""
+    win.erase()
+    # Derive the actual width of the window so we never draw past its edge.
+    _, max_x = win.getmaxyx()
+    effective_width = max_x or width
+    padding = 3  # leave space for arrow and a small gap
+    cols = max(0, effective_width - padding)
+
+    # Clamp buffer to visible width
+    visible = graph_buf[-cols:] if len(graph_buf) > cols else graph_buf
+    fill_len = len(visible)
+
+    # arrow first
+    if effective_width > 0:
+        arrow = "▲" if direction_up else "▼"
+        arrow_color = curses.color_pair(6 if direction_up else 5)
+        try:
+            win.addstr(0, 0, arrow, arrow_color)
+        except curses.error:
+            pass
+
+    # draw filled section
+    for i, val in enumerate(visible):
+        col = padding + i
+        if col >= effective_width:
+            break
+        color = curses.color_pair(6 if val > 0 else 5)
+        try:
+            win.addstr(0, col, "█", color)
+        except curses.error:
+            break
+
+    # fill remaining with ░
+    remaining = max(0, cols - fill_len)
+    fill_start = padding + fill_len
+    if remaining > 0 and fill_start < effective_width:
+        run = min(remaining, effective_width - fill_start)
+        if run > 0:
+            try:
+                win.addstr(0, fill_start, "░" * run, curses.color_pair(7))
+            except curses.error:
+                pass
+
+    win.noutrefresh()
+
+
+def draw_number(win, digits, scroll):
+    win.erase()
+    cols = curses.COLS
+    lines = [digits[i:i + cols - 1] for i in range(0, len(digits), cols - 1)]
+    max_lines = win.getmaxyx()[0]
+    scroll = max(0, min(scroll, max(0, len(lines) - max_lines)))
+    for i, chunk in enumerate(lines[scroll:scroll + max_lines]):
+        try:
+            win.addstr(i, 0, chunk, curses.color_pair(3))
+        except curses.error:
+            pass
+    win.noutrefresh()
+    return scroll
+
+
+def draw_log_list(win, scroll):
+    win.erase()
+    if not LOG_DIR.exists():
+        LOG_DIR.mkdir(parents=True, exist_ok=True)
+    files = sorted(LOG_DIR.iterdir(), key=os.path.getmtime, reverse=True)
+    names = [f"{f.name}" for f in files]
+    max_lines = win.getmaxyx()[0]
+    scroll = max(0, min(scroll, max(0, len(names) - max_lines)))
+    for i, name in enumerate(names[scroll:scroll + max_lines]):
+        try:
+            win.addstr(i, 0, name[: curses.COLS - 1], curses.color_pair(4))
+        except curses.error:
+            pass
+    win.noutrefresh()
+    return scroll
+
+
+def run_collatz(stdscr):
+    curses.curs_set(0)
+    curses.start_color()
+    curses.use_default_colors()
+    curses.init_pair(1, curses.COLOR_CYAN, -1)   # header text
+    curses.init_pair(2, curses.COLOR_BLACK, curses.COLOR_CYAN)  # separator
+    curses.init_pair(3, curses.COLOR_WHITE, -1)  # number
+    curses.init_pair(4, curses.COLOR_YELLOW, -1)  # log list
+    curses.init_pair(5, curses.COLOR_RED, -1)
+    curses.init_pair(6, curses.COLOR_GREEN, -1)
+    curses.init_pair(7, curses.COLOR_WHITE, -1)  # grey for empty
+
+    stdscr.nodelay(True)
+    stdscr.timeout(100)
+
+    start_file = Path("start.txt")
+    if not start_file.exists():
+        stdscr.addstr(0, 0, "Missing start.txt — please create one with your starting number.")
+        stdscr.refresh()
+        stdscr.getch()
+        return
+
+    clear_logs()
+    n = StreamNumber(start_file)
+    one, two, three = (StreamNumber(literal=s) for s in ("1", "2", "3"))
+
+    start_time = time.time()
+    step = 0
+    num_scroll = 0
+    log_scroll = 0
+
+    header_h = 5
+    graph_h = 1
+    num_h = (curses.LINES - header_h - graph_h) * 3 // 4
+    log_h = curses.LINES - header_h - graph_h - num_h - 1
+
+    num_win = curses.newwin(num_h, curses.COLS, header_h + graph_h + 1, 0)
+    graph_win = curses.newwin(graph_h, curses.COLS, header_h + 1, 0)
+    log_win = curses.newwin(log_h, curses.COLS, header_h + graph_h + num_h + 2, 0)
+
+    last_len = 0
+    graph_buf = []
+
+    while True:
+        step += 1
+        n = collatz_step(n, three, two, one)
+        digits = "".join(n.stream()) or "0"
+        cur_len = len(digits)
+        diff = cur_len - last_len
+        last_len = cur_len
+
+        graph_width = curses.COLS - 4
+
+        # Add new value to graph buffer
+        if diff != 0:
+            graph_buf.append(1 if diff > 0 else -1)
+        else:
+            graph_buf.append(0)
+
+        # Shift left if full
+        if len(graph_buf) > graph_width:
+            graph_buf = graph_buf[-graph_width:]
+
+        direction_up = diff >= 0
+        elapsed = time.time() - start_time
+        avg_step = elapsed / step if step else 0.0
+
+        draw_header(stdscr, step, elapsed, avg_step, len(digits))
+        draw_graph(graph_win, graph_buf, direction_up, curses.COLS)
+        num_scroll = draw_number(num_win, digits, num_scroll)
+        log_scroll = draw_log_list(log_win, log_scroll)
+
+        curses.doupdate()
+
+        ch = stdscr.getch()
+        if ch == ord("q"):
+            break
+        elif ch == curses.KEY_UP:
+            num_scroll = max(0, num_scroll - 1)
+        elif ch == curses.KEY_DOWN:
+            num_scroll += 1
+        elif ch == curses.KEY_PPAGE:
+            log_scroll = max(0, log_scroll - 3)
+        elif ch == curses.KEY_NPAGE:
+            log_scroll += 3
+
+        if digits == "1":
+            stdscr.nodelay(False)
+            stdscr.addstr(curses.LINES - 1, 0, "Reached 1 — press any key to exit.")
+            stdscr.refresh()
+            stdscr.getch()
+            break
+
+
+def main():
+    curses.wrapper(run_collatz)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/start.txt b/start.txt
new file mode 100644
index 0000000..1f32b3e
--- /dev/null
+++ b/start.txt
@@ -0,0 +1 @@
+55569392576944383732069997790263232211253447162098935262971634652345115098934212633724484589756741539606575
diff --git a/test.py b/test.py
index dc520db..ddbf5bc 100644
--- a/test.py
+++ b/test.py
@@ -15,6 +15,8 @@ from mathstream import (
     clear_logs,
     collect_garbage,
     DivideByZeroError,
+    active_streams,
+    tracked_files,
 )
 
 NUMBERS_DIR = Path(__file__).parent / "tests"
@@ -103,11 +105,34 @@ def main() -> None:
     else:
         raise AssertionError("mod by zero did not raise DivideByZeroError")
 
+    # manual frees should immediately drop staged files
+    staged = [
+        total,
+        difference,
+        product,
+        quotient,
+        powered,
+        modulus,
+        neg_mod_pos,
+        pos_mod_neg,
+        neg_mod_neg,
+        literal_combo,
+    ]
+    for stream in staged:
+        stream.free()
+
+    literal_even.free()
+    literal_odd.free()
+    zero_literal.free()
+
+    check_bool("total freed file gone", total.path.exists(), False)
+    check_bool("literal_even freed file gone", literal_even.path.exists(), False)
+
     removed = collect_garbage(0)
-    print(f"collect_garbage removed {len(removed)} files")
-    check_bool("total exists post GC", total.path.exists(), False)
-    check_bool("literal_even exists post GC", literal_even.path.exists(), False)
+    print(f"collect_garbage removed {len(removed)} files after manual free")
     check_bool("huge operand persists", big.path.exists(), True)
+    print("Active streams:", active_streams())
+    print("Tracked files:", tracked_files())
 
 
 if __name__ == "__main__":
diff --git a/tests/start.1762331106.txt b/tests/start.1762331106.txt
new file mode 100644
index 0000000..e56a9e9
--- /dev/null
+++ b/tests/start.1762331106.txt
@@ -0,0 +1 @@
+993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887993284887