feat(cli): extract streaming renderer to stream.py with Rich Live

Move ThinkingSpinner and StreamRenderer into a dedicated module to keep
commands.py focused on orchestration. Uses Rich Live with manual refresh
(auto_refresh=False) and ellipsis overflow for stable streaming output.

Made-with: Cursor

nanobot/cli/commands.py

@@ -33,6 +33,7 @@ from rich.table import Table
 from rich.text import Text
 
 from nanobot import __logo__, __version__
+from nanobot.cli.stream import StreamRenderer, ThinkingSpinner
 from nanobot.config.paths import get_workspace_path
 from nanobot.config.schema import Config
 from nanobot.utils.helpers import sync_workspace_templates
@@ -188,46 +189,13 @@ async def _print_interactive_response(
     await run_in_terminal(_write)
 
 
-class _ThinkingSpinner:
-    """Spinner wrapper with pause support for clean progress output."""
-
-    def __init__(self, enabled: bool):
-        self._spinner = console.status(
-            "[dim]nanobot is thinking...[/dim]", spinner="dots"
-        ) if enabled else None
-        self._active = False
-
-    def __enter__(self):
-        if self._spinner:
-            self._spinner.start()
-        self._active = True
-        return self
-
-    def __exit__(self, *exc):
-        self._active = False
-        if self._spinner:
-            self._spinner.stop()
-        return False
-
-    @contextmanager
-    def pause(self):
-        """Temporarily stop spinner while printing progress."""
-        if self._spinner and self._active:
-            self._spinner.stop()
-        try:
-            yield
-        finally:
-            if self._spinner and self._active:
-                self._spinner.start()
-
-
-def _print_cli_progress_line(text: str, thinking: _ThinkingSpinner | None) -> None:
+def _print_cli_progress_line(text: str, thinking: ThinkingSpinner | None) -> None:
     """Print a CLI progress line, pausing the spinner if needed."""
     with thinking.pause() if thinking else nullcontext():
         console.print(f"  [dim]↳ {text}[/dim]")
 
 
-async def _print_interactive_progress_line(text: str, thinking: _ThinkingSpinner | None) -> None:
+async def _print_interactive_progress_line(text: str, thinking: ThinkingSpinner | None) -> None:
     """Print an interactive progress line, pausing the spinner if needed."""
     with thinking.pause() if thinking else nullcontext():
         await _print_interactive_line(text)
@@ -755,7 +723,7 @@ def agent(
     )
 
     # Shared reference for progress callbacks
-    _thinking: _ThinkingSpinner | None = None
+    _thinking: ThinkingSpinner | None = None
 
     async def _cli_progress(content: str, *, tool_hint: bool = False) -> None:
         ch = agent_loop.channels_config
@@ -768,13 +736,14 @@ def agent(
     if message:
         # Single message mode — direct call, no bus needed
         async def run_once():
-            nonlocal _thinking
-            _thinking = _ThinkingSpinner(enabled=not logs)
-            with _thinking:
+            renderer = StreamRenderer(render_markdown=markdown)
             response = await agent_loop.process_direct(
-                    message, session_id, on_progress=_cli_progress,
+                message, session_id,
+                on_progress=_cli_progress,
+                on_stream=renderer.on_delta,
+                on_stream_end=renderer.on_end,
             )
-            _thinking = None
+            if not renderer.streamed:
                 _print_agent_response(
                     response.content if response else "",
                     render_markdown=markdown,
@@ -815,11 +784,27 @@ def agent(
             turn_done = asyncio.Event()
             turn_done.set()
             turn_response: list[tuple[str, dict]] = []
+            renderer: StreamRenderer | None = None
 
             async def _consume_outbound():
                 while True:
                     try:
                         msg = await asyncio.wait_for(bus.consume_outbound(), timeout=1.0)
+
+                        if msg.metadata.get("_stream_delta"):
+                            if renderer:
+                                await renderer.on_delta(msg.content)
+                            continue
+                        if msg.metadata.get("_stream_end"):
+                            if renderer:
+                                await renderer.on_end(
+                                    resuming=msg.metadata.get("_resuming", False),
+                                )
+                            continue
+                        if msg.metadata.get("_streamed"):
+                            turn_done.set()
+                            continue
+
                         if msg.metadata.get("_progress"):
                             is_tool_hint = msg.metadata.get("_tool_hint", False)
                             ch = agent_loop.channels_config
@@ -829,8 +814,9 @@ def agent(
                                 pass
                             else:
                                 await _print_interactive_progress_line(msg.content, _thinking)
+                            continue
 
-                        elif not turn_done.is_set():
+                        if not turn_done.is_set():
                             if msg.content:
                                 turn_response.append((msg.content, dict(msg.metadata or {})))
                             turn_done.set()
@@ -864,23 +850,24 @@ def agent(
 
                         turn_done.clear()
                         turn_response.clear()
+                        renderer = StreamRenderer(render_markdown=markdown)
 
                         await bus.publish_inbound(InboundMessage(
                             channel=cli_channel,
                             sender_id="user",
                             chat_id=cli_chat_id,
                             content=user_input,
+                            metadata={"_wants_stream": True},
                         ))
 
-                        nonlocal _thinking
-                        _thinking = _ThinkingSpinner(enabled=not logs)
-                        with _thinking:
                         await turn_done.wait()
-                        _thinking = None
 
                         if turn_response:
                             content, meta = turn_response[0]
-                            _print_agent_response(content, render_markdown=markdown, metadata=meta)
+                            if content and not meta.get("_streamed"):
+                                _print_agent_response(
+                                    content, render_markdown=markdown, metadata=meta,
+                                )
                     except KeyboardInterrupt:
                         _restore_terminal()
                         console.print("\nGoodbye!")

nanobot/cli/stream.py

@@ -0,0 +1,128 @@
+"""Streaming renderer for CLI output.
+
+Uses Rich Live with auto_refresh=False for stable, flicker-free
+markdown rendering during streaming. Ellipsis mode handles overflow.
+"""
+
+from __future__ import annotations
+
+import re
+import sys
+import time
+from typing import Any
+
+from rich.console import Console
+from rich.live import Live
+from rich.markdown import Markdown
+from rich.text import Text
+
+from nanobot import __logo__
+
+
+def _make_console() -> Console:
+    return Console(file=sys.stdout)
+
+
+class ThinkingSpinner:
+    """Spinner that shows 'nanobot is thinking...' with pause support."""
+
+    def __init__(self, console: Console | None = None):
+        c = console or _make_console()
+        self._spinner = c.status("[dim]nanobot is thinking...[/dim]", spinner="dots")
+        self._active = False
+
+    def __enter__(self):
+        self._spinner.start()
+        self._active = True
+        return self
+
+    def __exit__(self, *exc):
+        self._active = False
+        self._spinner.stop()
+        return False
+
+    def pause(self):
+        """Context manager: temporarily stop spinner for clean output."""
+        from contextlib import contextmanager
+
+        @contextmanager
+        def _ctx():
+            if self._spinner and self._active:
+                self._spinner.stop()
+            try:
+                yield
+            finally:
+                if self._spinner and self._active:
+                    self._spinner.start()
+
+        return _ctx()
+
+
+class StreamRenderer:
+    """Rich Live streaming with markdown. auto_refresh=False avoids render races.
+
+    Flow per round:
+      spinner -> first visible delta -> header + Live renders ->
+      on_end -> Live stops (content stays on screen)
+    """
+
+    def __init__(self, render_markdown: bool = True, show_spinner: bool = True):
+        self._md = render_markdown
+        self._show_spinner = show_spinner
+        self._buf = ""
+        self._live: Live | None = None
+        self._t = 0.0
+        self.streamed = False
+        self._spinner: ThinkingSpinner | None = None
+        self._start_spinner()
+
+    @staticmethod
+    def _clean(text: str) -> str:
+        text = re.sub(r"<think>[\s\S]*?</think>", "", text)
+        text = re.sub(r"<think>[\s\S]*$", "", text)
+        return text.strip()
+
+    def _render(self):
+        clean = self._clean(self._buf)
+        return Markdown(clean) if self._md and clean else Text(clean or "")
+
+    def _start_spinner(self) -> None:
+        if self._show_spinner:
+            self._spinner = ThinkingSpinner()
+            self._spinner.__enter__()
+
+    def _stop_spinner(self) -> None:
+        if self._spinner:
+            self._spinner.__exit__(None, None, None)
+            self._spinner = None
+
+    async def on_delta(self, delta: str) -> None:
+        self.streamed = True
+        self._buf += delta
+        if self._live is None:
+            if not self._clean(self._buf):
+                return
+            self._stop_spinner()
+            c = _make_console()
+            c.print()
+            c.print(f"[cyan]{__logo__} nanobot[/cyan]")
+            self._live = Live(self._render(), console=c, auto_refresh=False)
+            self._live.start()
+        now = time.monotonic()
+        if "\n" in delta or (now - self._t) > 0.05:
+            self._live.update(self._render())
+            self._live.refresh()
+            self._t = now
+
+    async def on_end(self, *, resuming: bool = False) -> None:
+        if self._live:
+            self._live.update(self._render())
+            self._live.refresh()
+            self._live.stop()
+            self._live = None
+        self._stop_spinner()
+        if resuming:
+            self._buf = ""
+            self._start_spinner()
+        else:
+            _make_console().print()

tests/test_cli_input.py

@@ -5,6 +5,7 @@ import pytest
 from prompt_toolkit.formatted_text import HTML
 
 from nanobot.cli import commands
+from nanobot.cli import stream as stream_mod
 
 
 @pytest.fixture
@@ -62,9 +63,10 @@ def test_init_prompt_session_creates_session():
 def test_thinking_spinner_pause_stops_and_restarts():
     """Pause should stop the active spinner and restart it afterward."""
     spinner = MagicMock()
+    mock_console = MagicMock()
+    mock_console.status.return_value = spinner
 
-    with patch.object(commands.console, "status", return_value=spinner):
-        thinking = commands._ThinkingSpinner(enabled=True)
+    thinking = stream_mod.ThinkingSpinner(console=mock_console)
     with thinking:
         with thinking.pause():
             pass
@@ -83,10 +85,11 @@ def test_print_cli_progress_line_pauses_spinner_before_printing():
     spinner = MagicMock()
     spinner.start.side_effect = lambda: order.append("start")
     spinner.stop.side_effect = lambda: order.append("stop")
+    mock_console = MagicMock()
+    mock_console.status.return_value = spinner
 
-    with patch.object(commands.console, "status", return_value=spinner), \
-         patch.object(commands.console, "print", side_effect=lambda *_args, **_kwargs: order.append("print")):
-        thinking = commands._ThinkingSpinner(enabled=True)
+    with patch.object(commands.console, "print", side_effect=lambda *_args, **_kwargs: order.append("print")):
+        thinking = stream_mod.ThinkingSpinner(console=mock_console)
         with thinking:
             commands._print_cli_progress_line("tool running", thinking)
 
@@ -100,13 +103,14 @@ async def test_print_interactive_progress_line_pauses_spinner_before_printing():
     spinner = MagicMock()
     spinner.start.side_effect = lambda: order.append("start")
     spinner.stop.side_effect = lambda: order.append("stop")
+    mock_console = MagicMock()
+    mock_console.status.return_value = spinner
 
     async def fake_print(_text: str) -> None:
         order.append("print")
 
-    with patch.object(commands.console, "status", return_value=spinner), \
-         patch("nanobot.cli.commands._print_interactive_line", side_effect=fake_print):
-        thinking = commands._ThinkingSpinner(enabled=True)
+    with patch("nanobot.cli.commands._print_interactive_line", side_effect=fake_print):
+        thinking = stream_mod.ThinkingSpinner(console=mock_console)
         with thinking:
             await commands._print_interactive_progress_line("tool running", thinking)