diff --git a/bench/run.py b/bench/run.py
index 0a2da55..2038860 100644
--- a/bench/run.py
+++ b/bench/run.py
@@ -33,44 +33,28 @@ from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).resolve().parent))
 import tasks as T  # noqa: E402
+from tui import agent_online, capture, clear_input, send_command  # noqa: E402
 
 
 def sh(cmd, **kw):
     return subprocess.run(cmd, capture_output=True, text=True, **kw)
 
 
-def tmux(*args):
-    return sh(["tmux", *args])
-
-
-def capture(target, lines=4000):
-    """Full scrollback of the TUI pane as text."""
-    r = tmux("capture-pane", "-t", target, "-p", "-S", f"-{lines}")
-    return r.stdout
-
-
 def podman(container, snippet):
     """Run a POSIX-sh snippet in the container; return (rc, output)."""
     r = sh(["podman", "exec", container, "sh", "-c", snippet])
     return r.returncode, (r.stdout + r.stderr).strip()
 
 
-def agent_online(target, model):
-    return f"{model} (ai) online" in capture(target) or "online — ollama" in capture(target)
-
-
 def is_thinking(buf):
     return "is thinking" in buf
 
 
 def send_task(target, model, prompt):
-    """Clear the input box, then type the /ai command and submit it."""
-    # The TUI has no kill-line; clear with backspaces (harmless when empty).
-    tmux("send-keys", "-t", target, *(["BSpace"] * 6))
-    time.sleep(0.3)
-    tmux("send-keys", "-t", target, "-l", f"/ai {model} !{prompt}")
-    time.sleep(0.3)
-    tmux("send-keys", "-t", target, "Enter")
+    """Robustly clear the input box, then type and submit the /ai command. The
+    box is fully backspace-cleared and the Enter is verified (see tui.py), so a
+    dropped keystroke can't leave a half-typed prompt to corrupt the next task."""
+    send_command(target, f"/ai {model} !{prompt}")
 
 
 def scrape_summary(target, user):
@@ -197,11 +181,16 @@ def main():
     print(f"running {len(selected)} task(s) against {args.model} "
           f"(container={args.container}, tui={args.target})")
     rows = []
-    for i, task in enumerate(selected, 1):
-        print(f"[{i}/{len(selected)}] {task.id} … ", end="", flush=True)
-        r = run_task(args, task)
-        print(f"{r['result']} ({r['secs']}s)")
-        rows.append(r)
+    try:
+        for i, task in enumerate(selected, 1):
+            print(f"[{i}/{len(selected)}] {task.id} … ", end="", flush=True)
+            r = run_task(args, task)
+            print(f"{r['result']} ({r['secs']}s)")
+            rows.append(r)
+    finally:
+        # Leave the input box empty so the next action (e.g. an agent restart)
+        # isn't corrupted by a lingering prompt.
+        clear_input(args.target)
 
     print_table(rows)
 
diff --git a/bench/tui.py b/bench/tui.py
new file mode 100644
index 0000000..e00d86c
--- /dev/null
+++ b/bench/tui.py
@@ -0,0 +1,180 @@
+#!/usr/bin/env python3
+"""Robust primitives for driving the hack-house Rust TUI headlessly via tmux.
+
+The TUI is a full-screen ratatui app whose message box has **no line-editing
+shortcuts** — Ctrl-A/U/K arrive as the literal letters a/u/k, so the only way to
+clear the input is Backspace. A single `Enter` also doesn't always register, so
+every primitive here VERIFIES the on-screen input line and retries instead of
+firing keystrokes blind. Shared by `run.py` (task sending) and the agent-restart
+CLI below so both stop leaking stale text into the box.
+
+Online/grant detection counts occurrences in the scrollback and waits for the
+count to *increase* — never just "is the needle present" — because a previous
+`/ai start <same-model>` leaves a stale "online" line that a naive check would
+match immediately.
+
+CLI:
+    python bench/tui.py restart <model> [--target hh-house:2]
+    python bench/tui.py clear            [--target hh-house:2]
+    python bench/tui.py send '<text>'    [--target hh-house:2]
+"""
+
+import argparse
+import re
+import subprocess
+import sys
+import time
+
+DEFAULT_TARGET = "hh-house:2"
+
+# The message box bottom line looks like:  │> some text              │
+# Capture the text between the prompt and the box's right border.
+_INPUT_RE = re.compile(r"│>\s?(.*)│\s*$")
+
+
+def tmux(*args):
+    return subprocess.run(["tmux", *args], capture_output=True, text=True)
+
+
+def capture(target, lines=None):
+    """The current VISIBLE screen of the TUI pane.
+
+    Deliberately NO `-S`/scrollback: this is a full-screen alt-screen app, so
+    `capture-pane -S -N` returns stale or empty buffer frames (it once reported
+    an agent in the clergy that the live screen had already dropped). Only the
+    live viewport is trustworthy. The `lines` arg is accepted for call-site
+    compatibility but ignored."""
+    return tmux("capture-pane", "-t", target, "-p").stdout
+
+
+def input_text(target):
+    """Current contents of the message input box (best-effort, '' when empty)."""
+    for line in reversed(capture(target, lines=60).splitlines()):
+        m = _INPUT_RE.search(line)
+        if m:
+            return m.group(1).rstrip()
+    return ""
+
+
+def clear_input(target, tries=12, burst=120):
+    """Backspace the input box until it reads empty. Harmless when already empty."""
+    for _ in range(tries):
+        if not input_text(target):
+            return True
+        tmux("send-keys", "-t", target, *(["BSpace"] * burst))
+        time.sleep(0.25)
+    return not input_text(target)
+
+
+def submit(target, tries=5):
+    """Press Enter until the input box empties (i.e. the line was actually sent)."""
+    for _ in range(tries):
+        tmux("send-keys", "-t", target, "Enter")
+        time.sleep(0.6)
+        if not input_text(target):
+            return True
+    return not input_text(target)
+
+
+def send_command(target, text):
+    """Clear the box, type `text`, and submit it with verification. Returns bool."""
+    clear_input(target)
+    tmux("send-keys", "-t", target, "-l", text)
+    time.sleep(0.3)
+    return submit(target)
+
+
+def _columns(target):
+    """Split the two side-by-side panels. The TUI is a full-screen alt-screen
+    app, so `capture-pane` only ever returns the VISIBLE viewport (no
+    scrollback) — counting chat events is therefore unreliable, but the clergy
+    roster on the right is present-tense and doesn't scroll. Returns
+    (chat_text, clergy_text)."""
+    chat, clergy = [], []
+    for line in capture(target).splitlines():
+        parts = line.split("│")
+        if len(parts) >= 5:          # │ chat ││ clergy │
+            chat.append(parts[1])
+            clergy.append(parts[3])
+    return "\n".join(chat), "\n".join(clergy)
+
+
+def agent_online(target, model):
+    """True iff `model` is currently listed in the clergy roster panel — the
+    one signal that reflects live state instead of scrolled-away history."""
+    return model in _columns(target)[1]
+
+
+def wait_state(target, predicate, timeout, poll=2.0):
+    deadline = time.time() + timeout
+    while time.time() < deadline:
+        if predicate():
+            return True
+        time.sleep(poll)
+    return False
+
+
+def restart_agent(target, model, online_timeout=180, start_tries=2):
+    """Stop the current agent, start `model`, and grant it drive — each step
+    verified against the live clergy roster so a hung spawn is retried rather
+    than a healthy one dismissed. Returns True only if the new agent is online
+    AND holds drive.
+
+    `online_timeout` is deliberately generous: a cold `/ai start` reloads the
+    model into Ollama and routinely takes 60–90 s on the CPU-only box, so a
+    tight window would kill a slow-but-healthy spawn and churn it into a stuck
+    summon (exactly what the old aggressive retry caused)."""
+    send_command(target, "/ai stop")
+    wait_state(target, lambda: not agent_online(target, model), 20)
+
+    started = False
+    for _ in range(start_tries):
+        send_command(target, f"/ai start {model}")
+        if wait_state(target, lambda: agent_online(target, model), online_timeout):
+            started = True
+            break
+        # spawn hung — dismiss the stuck summon and try once more
+        send_command(target, "/ai stop")
+        wait_state(target, lambda: not agent_online(target, model), 20)
+    if not started:
+        return False
+
+    time.sleep(2)  # let the roster settle before granting
+    send_command(target, "/grant ai")
+    granted = f"granted drive to all AI agents: {model}"
+    return wait_state(target, lambda: granted in _columns(target)[0], 20)
+
+
+def main():
+    ap = argparse.ArgumentParser(description="Drive the hack-house TUI via tmux.")
+    ap.add_argument("action", choices=["restart", "clear", "send", "show"])
+    ap.add_argument("arg", nargs="?", help="model (restart) or text (send)")
+    ap.add_argument("--target", default=DEFAULT_TARGET, help="tmux window of the TUI")
+    a = ap.parse_args()
+
+    if a.action == "clear":
+        ok = clear_input(a.target)
+        print("input clear" if ok else "! input still has text")
+        return 0 if ok else 1
+    if a.action == "show":
+        print(repr(input_text(a.target)))
+        return 0
+    if a.action == "send":
+        if not a.arg:
+            print("send needs text", file=sys.stderr)
+            return 2
+        ok = send_command(a.target, a.arg)
+        print("sent" if ok else "! could not submit (box not empty)")
+        return 0 if ok else 1
+    if a.action == "restart":
+        if not a.arg:
+            print("restart needs a model", file=sys.stderr)
+            return 2
+        ok = restart_agent(a.target, a.arg)
+        print(f"{a.arg} online+drive" if ok else f"! {a.arg} restart failed")
+        return 0 if ok else 1
+    return 2
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())