NVIDIA-NeMo · andreatgretel · Jul 7, 2026 · Jul 7, 2026 · Jul 7, 2026 · Jul 7, 2026
@@ -149,7 +149,7 @@ class RunConfig(ConfigBase):
         async_trace: If True, collect per-task tracing data. Default is False.
         display_tui: If True, display the terminal throughput TUI instead of periodic
             log lines during generation. Requires a TTY; falls back to log lines in
-            non-TTY environments. Default is True.
+            non-TTY environments. Default is False.
         progress_interval: How often (in seconds) the async progress reporter emits a
             consolidated log block. Must be > 0. Default is 5.0.
         preserve_dropped_columns: If True, write columns removed by drop processors to
@@ -185,7 +185,7 @@ class RunConfig(ConfigBase):
     max_conversation_restarts: int = Field(default=5, ge=0)
     max_conversation_correction_steps: int = Field(default=0, ge=0)
     async_trace: bool = False
-    display_tui: bool = True
+    display_tui: bool = False
     progress_interval: float = Field(default=5.0, gt=0.0)
     preserve_dropped_columns: bool = Field(
         default=True,

@@ -24,8 +24,8 @@ def test_run_config_accepts_native_renderer() -> None:
     assert JinjaRenderingEngine(run_config.jinja_rendering_engine) == JinjaRenderingEngine.NATIVE
 
 
-def test_run_config_defaults_to_display_tui_enabled() -> None:
-    assert RunConfig().display_tui is True
+def test_run_config_defaults_to_display_tui_disabled() -> None:
+    assert RunConfig().display_tui is False
 
 
 def test_run_config_accepts_display_tui() -> None:

@@ -63,6 +63,7 @@ dependencies = [
     "sqlfluff>=4.1.0,<5",
     "starlette>=1.2.0,<2", # 1.2.0 fixes security advisory pulled in by mcp
     "tiktoken>=0.8.0,<1",
+    "wcwidth>=0.2.13,<1",
 ]
 
 [tool.hatch.build.targets.wheel]

@@ -13,6 +13,7 @@
 from typing import Sequence, TextIO
 
 import asciichartpy
+from wcwidth import wcswidth
 
 _ANSI_RE = re.compile(r"\033\[[0-9;?]*[a-zA-Z]")
 _CONTROL_RE = re.compile(r"[\x00-\x1f\x7f-\x9f]")
@@ -67,13 +68,24 @@
 
 
 def _visible_len(text: str) -> int:
-    return len(_ANSI_RE.sub("", text))
+    visible = _ANSI_RE.sub("", text)
+    width = wcswidth(visible)
+    return width if width >= 0 else len(visible)
+
+
+def _truncate_to_width(text: str, width: int) -> str:
+    for index in range(1, len(text) + 1):
+        prefix_width = wcswidth(text[:index])
+        if prefix_width < 0 or prefix_width > width:
+            return text[: index - 1]
+    return text
 
 
 def _fit_ansi(text: str, width: int) -> str:
     visible = _visible_len(text)
     if visible > width:
-        return _ANSI_RE.sub("", text)[:width] + _RESET
+        fitted = _truncate_to_width(_ANSI_RE.sub("", text), width)
+        return fitted + (" " * (width - _visible_len(fitted))) + _RESET
     return text + (" " * (width - visible))
 
 
@@ -87,7 +99,8 @@ def sanitize_terminal_text(label: str) -> str:
 
 def _fit_plain(text: str, width: int) -> str:
     clean = sanitize_terminal_text(text)
-    return clean[:width].ljust(width)
+    fitted = _truncate_to_width(clean, width)
+    return fitted + (" " * (width - _visible_len(fitted)))
 
 
 def _average(values: Sequence[float]) -> float:
@@ -294,6 +307,7 @@ def __init__(self, stream: TextIO | None = None, *, panel_height: int = _DEFAULT
         self._feedback_markers: list[_FeedbackMarker] = []
         self._lock = Lock()
         self._drawn_lines = 0
+        self._drawn_terminal_size: tuple[int, int] | None = None
         self._active = False
         self._owns_stream = False
         self._wrapped_handlers: list[tuple[logging.StreamHandler, object]] = []
@@ -344,6 +358,7 @@ def __exit__(self, *args: object) -> None:
                 self._unwrap_handlers()
                 self._active = False
                 self._drawn_lines = 0
+                self._drawn_terminal_size = None
         finally:
             self._release_stream()
 
@@ -489,12 +504,16 @@ def _unwrap_handlers(self) -> None:
 
     def _clear_bars(self) -> None:
         """Clear drawn panel lines from the terminal. Caller must hold the lock."""
+        terminal_size = shutil.get_terminal_size()
         if self._drawn_lines > 0:
-            clear_count = min(self._drawn_lines, max(0, shutil.get_terminal_size().lines - 1))
+            clear_count = min(self._drawn_lines, max(0, terminal_size.lines - 1))
             for _ in range(clear_count):
                 self._write("\033[A\033[2K")
             self._write("\r\033[2K")
             self._drawn_lines = 0
+        if self._drawn_terminal_size is not None and self._drawn_terminal_size != tuple(terminal_size):
+            self._write("\033[J")
+        self._drawn_terminal_size = None
 
     def _redraw_if_due(self, now: float, *, force: bool = False) -> None:
         if force or self._drawn_lines == 0 or now - self._last_redraw_time >= _MIN_REDRAW_INTERVAL_SECONDS:
@@ -504,7 +523,7 @@ def _redraw(self, *, force: bool = False, now: float | None = None) -> None:
         """Redraw the chart panel. Caller must hold the lock."""
         terminal_size = shutil.get_terminal_size()
         if terminal_size.columns < _MIN_TERMINAL_WIDTH or terminal_size.lines < _MIN_TERMINAL_HEIGHT:
-            self._drawn_lines = 0
+            self._clear_bars()
             self._write("\033[?25h")
             self._unwrap_handlers()
             self._active = False
@@ -521,6 +540,7 @@ def _redraw(self, *, force: bool = False, now: float | None = None) -> None:
         for line in lines:
             self._write(line + "\n")
         self._drawn_lines = len(lines)
+        self._drawn_terminal_size = tuple(terminal_size)
         self._last_redraw_time = time.perf_counter() if now is None else now
 
     def _format_panel(self) -> list[str]:
@@ -736,7 +756,7 @@ def _column_table_widths(
         fixed_width_without_label_or_progress = (
             2 + (separator_count * _LEGEND_COLUMN_GAP) + done_width + (rate_width * 2) + status_width
         )
-        content_label_width = max(len("column"), *(len(sanitize_terminal_text(bar.label)) for bar in bars))
+        content_label_width = max(_visible_len("column"), *(_visible_len(bar.label) for bar in bars))
         desired_label_width = max(_MIN_LEGEND_LABEL_WIDTH, content_label_width)
         available_width = inner_width - fixed_width_without_label_or_progress
 
@@ -826,13 +846,13 @@ def _model_table_widths(
         available_text_width = inner_width - fixed_width_without_text
         desired_alias_width = max(
             _MIN_MODEL_ALIAS_WIDTH,
-            len("model alias"),
-            *(len(state.model_alias) for state in model_usage),
+            _visible_len("model alias"),
+            *(_visible_len(state.model_alias) for state in model_usage),
         )
         desired_model_width = max(
             _MIN_MODEL_NAME_WIDTH,
-            len("model name"),
-            *(len(state.model_name) for state in model_usage),
+            _visible_len("model name"),
+            *(_visible_len(state.model_name) for state in model_usage),
         )
 
         if available_text_width >= desired_alias_width + desired_model_width:

@@ -13,6 +13,7 @@
 from unittest.mock import patch
 
 import pytest
+from wcwidth import wcswidth
 
 from data_designer.engine.models.usage_events import TokenUsageEvent, emit_token_usage_event
 from data_designer.engine.observability import (
@@ -36,6 +37,7 @@
 CURSOR_UP_CLEAR = "\033[A\033[2K"
 HIDE_CURSOR = "\033[?25l"
 SHOW_CURSOR = "\033[?25h"
+ERASE_TO_END = "\033[J"
 _ALL_ANSI_RE = re.compile(r"\033\[[0-9;?]*[a-zA-Z]")
 
 
@@ -140,11 +142,16 @@ def test_only_one_panel_owns_a_stream(tty_stream: FakeTTY) -> None:
 def test_active_panel_falls_back_when_terminal_shrinks(tty_stream: FakeTTY) -> None:
     with TerminalThroughputPanel(stream=tty_stream) as bar:
         bar.add_bar("a", "column 'a'", 100)
+        snapshot = tty_stream.getvalue()
         with patch.object(shutil, "get_terminal_size", return_value=os.terminal_size((20, 5))):
             bar.update("a", completed=1, success=1, force=True)
             assert bar.is_active is False
             assert bar.drawn_lines == 0
 
+        resize_output = tty_stream.getvalue()[len(snapshot) :]
+        assert ERASE_TO_END in resize_output
+        assert resize_output.index(ERASE_TO_END) < resize_output.index(SHOW_CURSOR)
+
     assert tty_stream.getvalue().count(HIDE_CURSOR) == 1
     assert tty_stream.getvalue().count(SHOW_CURSOR) == 1
 
@@ -400,6 +407,53 @@ def test_narrow_terminal_keeps_panel_within_width(tty_stream: FakeTTY) -> None:
                 assert len(line) <= 35
 
 
+@pytest.mark.parametrize(
+    ("terminal_width", "label", "model_alias", "model_name"),
+    [
+        # Exercise double-width CJK/emoji, combining marks, and ZWJ sequences whose
+        # code-point counts differ from their displayed terminal cell widths.
+        (30, "列🚀" * 20, "模型" * 20, "提供者/模型" * 20),
+        (36, "e\u0301" * 20, "👩🏽‍💻" * 20, "模型/e\u0301" * 20),
+        (50, "列🚀" * 20, "模型" * 20, "提供者/模型" * 20),
+        (80, "e\u0301" * 20, "👩🏽‍💻" * 20, "模型/e\u0301" * 20),
+    ],
+)
+def test_wide_unicode_labels_stay_within_terminal_width(
+    tty_stream: FakeTTY,
+    terminal_width: int,
+    label: str,
+    model_alias: str,
+    model_name: str,
+) -> None:
+    with patch.object(shutil, "get_terminal_size", return_value=os.terminal_size((terminal_width, 24))):
+        with TerminalThroughputPanel(stream=tty_stream) as bar:
+            bar.add_bar("a", label, 100)
+            bar.record_model_usage(
+                model_alias=model_alias,
+                model_name=model_name,
+                input_tokens=100,
+                output_tokens=25,
+                force=True,
+            )
+
+            assert all(wcswidth(line) == terminal_width - 1 for line in _last_panel_lines(tty_stream.getvalue()))
+
+
+def test_active_panel_clears_visible_artifacts_when_terminal_resizes(tty_stream: FakeTTY) -> None:
+    terminal_size = os.terminal_size((80, 24))
+
+    with patch.object(shutil, "get_terminal_size", side_effect=lambda: terminal_size):
+        with TerminalThroughputPanel(stream=tty_stream) as bar:
+            bar.add_bar("a", "column 'a'", 100)
+            snapshot = tty_stream.getvalue()
+            terminal_size = os.terminal_size((50, 12))
+
+            bar.update("a", completed=1, success=1, force=True)
+
+            assert bar.is_active is True
+            assert ERASE_TO_END in tty_stream.getvalue()[len(snapshot) :]
+
+
 def test_update_many_single_redraw(tty_stream: FakeTTY) -> None:
     with TerminalThroughputPanel(stream=tty_stream) as bar:
         bar.add_bar("a", "col_a", 100)