argszero · argszero · Aug 19, 2026 · Aug 19, 2026 · Aug 19, 2026 · argszero
diff --git a/Agent.md b/Agent.md
@@ -118,7 +118,7 @@ Community needs voiced in HN agent-UI discussions map directly to EMRG's design:
 pkill -f "emrg.server"; rm -f ~/.emrg/emrgd.port; python -m emrg
 ```
 
-Python: `uv run pytest tests/ -v` (968) — import check: `uv run python -c "from emrg.client.app import run_client"`
+Python: `uv run pytest tests/ -v` (977) — import check: `uv run python -c "from emrg.client.app import run_client"`
 GUI: `cd emrg/gui && npm test` (260: 45 daemon_client + 19 conn-manager + 22 app-commands + 131 renderer smoke + 16 i18n + 7 integration + 3 commands + 8 build-config + 7 gui-state + 2 tool-group) — syntax: `node --check main.js preload.js daemon_client.js renderer/js/*.js`
 CI: `uv run pytest` (ubuntu + **windows-2025 matrix** — Windows pytest 回归在 PR CI 即失败，v0.2.29 教训 #725) + GUI tests + **actionlint workflow lint** (`rhysd/actionlint@v1.7.12` gate, #444 — workflow 解析错误在 PR CI 即失败，如 `if:` secrets 上下文)
 Re-trigger: `scripts/re-trigger-ci.sh [branch]` (workflow_dispatch, #527 — 替代空 commit 重触发：Actions outage 会整段丢弃 push 事件，dispatch 走 API 路径不受影响)

diff --git a/emrg/client/python_tui/widgets/composer.py b/emrg/client/python_tui/widgets/composer.py
@@ -140,28 +140,55 @@ def submit(self) -> str | None:
  return text
 
  def render(self, ctx: RenderContext) -> list[Line]:
- """Render the composer with prompt, text, and cursor indicator."""
+ """Render the composer with prompt, text, and cursor indicator.
+
+ Multi-line text (pasted input) renders as one Line per logical line:
+ the first line carries the prompt, continuation lines a same-width
+ indent, and the cursor is drawn on the line it currently sits in
+ (rant 2026-08-19T14:25:55 — a single Line with embedded ``\\n`` was
+ flattened by the buffer, which skips newline characters).
+ """
  is_placeholder = not self._text
 
- # Show cursor position
- if self._text and self._cursor < len(self._text):
- cursor_char = self._text[self._cursor]
- prefix = self._text[:self._cursor]
- suffix = self._text[self._cursor + 1:]
- else:
- cursor_char = " "
- prefix = self._text
- suffix = ""
-
- cursor_style = "reverse" if self._text else "dim"
- style = "dim" if is_placeholder else ""
-
+ if self._text:
+ content_lines = self._text.split("\n")
+ indent = " " * len(self.prompt)
+ lines_out: list[Line] = []
+ line_start = 0
+ for i, line_text in enumerate(content_lines):
+ line_end = line_start + len(line_text)
+ # Cursor lives in this line iff it is within [line_start, line_end].
+ cursor_here = line_start <= self._cursor <= line_end
+ if cursor_here:
+ rel = self._cursor - line_start
+ if rel < len(line_text):
+ cursor_char = line_text[rel]
+ prefix = line_text[:rel]
+ suffix = line_text[rel + 1:]
+ else: # cursor at end of this line (incl. on the newline)
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ else:
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ lines_out.append(Line(spans=[
+ Span(text=self.prompt if i == 0 else indent,
+ style="bold cyan" if i == 0 else "dim"),
+ Span(text=prefix, style="" if not is_placeholder else "dim"),
+ Span(text=cursor_char, style="reverse"),
+ Span(text=suffix, style="" if not is_placeholder else "dim"),
+ ], style=ctx.style))
+ line_start = line_end + 1 # skip the newline separator
+ self._dirty = False
+ return lines_out
+
+ # Empty / placeholder: single line with prompt + dim cursor block.
  spans = [
  Span(text=self.prompt, style="bold cyan"),
- Span(text=prefix, style=style),
- Span(text=cursor_char, style=cursor_style),
- Span(text=suffix, style=style),
+ Span(text=" ", style="dim"),
+ Span(text=" ", style="dim"),
  ]
-
  self._dirty = False
  return [Line(spans=spans, style=ctx.style)]
diff --git a/emrg/client/python_tui/widgets/markdown.py b/emrg/client/python_tui/widgets/markdown.py
@@ -56,6 +56,10 @@ class UserMarkdown(Markdown):
  ``> `` prefix + bold cyan role visual. The markdown is rendered at
  ``ctx.width - len(prefix)`` so the prefix on the first line never
  overflows the buffer width (continuation lines get a same-width indent).
+
+ Single newlines are preserved as hard line breaks (rant
+ 2026-08-19T14:25:55): Rich would otherwise collapse ``\\n`` into a
+ space, merging pasted multi-line messages into one wrapped line.
  """
 
  _ROLE_PREFIX = "> "
@@ -72,7 +76,7 @@ def render(self, ctx: RenderContext) -> list[Line]:
  role_style = Style.parse(self._ROLE_STYLE)
  avail = max(1, ctx.width - len(prefix))
 
- md = RichMarkdown(self.text, code_theme="monokai")
+ md = RichMarkdown(_preserve_line_breaks(self.text), code_theme="monokai")
  md_lines = rich_renderable_to_lines(md, avail)
  lines: list[Line] = []
  for i, line in enumerate(md_lines):
@@ -84,6 +88,29 @@ def render(self, ctx: RenderContext) -> list[Line]:
  return lines
 
 
+def _preserve_line_breaks(text: str) -> str:
+ """Turn single newlines into hard breaks so RichMarkdown keeps them.
+
+ Rich collapses a single ``\\n`` (markdown soft break) into a space, so
+ pasted multi-line user messages render as one long auto-wrapped line.
+ A CommonMark hard break is a line ending in two spaces — Rich renders
+ each such line separately. Blank lines (paragraph separators) and the
+ interior of fenced code blocks are left untouched: trailing whitespace
+ is significant inside code blocks.
+ """
+ out: list[str] = []
+ in_fence = False
+ for line in text.split("\n"):
+ if line.lstrip().startswith("```"):
+ in_fence = not in_fence
+ out.append(line)
+ elif in_fence or not line.strip():
+ out.append(line)
+ else:
+ out.append(line + " ")
+ return "\n".join(out)
+
+
 @dataclass
 class StreamingMarkdown(Widget):
  """Incremental markdown renderer for token-by-token streaming.

diff --git a/tests/test_composer.py b/tests/test_composer.py
@@ -0,0 +1,87 @@
+"""Tests for the Composer widget (multi-line input rendering).
+
+rant 2026-08-19T14:25:55: pasted multi-line text must render as one line
+per logical line — the first line carries the prompt, continuation lines a
+same-width indent, and the cursor is drawn on the line it currently sits
+in. (The old single-Line render was flattened by the buffer, which skips
+\\n characters → long auto-wrapped blob.)
+"""
+
+from __future__ import annotations
+
+from emrg.client.python_tui.widgets.base import RenderContext
+from emrg.client.python_tui.widgets.composer import Composer
+
+
+def _render_text(text: str, cursor: int | None = None) -> list[str]:
+ composer = Composer()
+ if text:
+ composer._text = text
+ composer._cursor = len(text) if cursor is None else cursor
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ return ["".join(s.text for s in line.spans) for line in lines]
+
+
+def test_composer_single_line():
+ """Single-line input keeps the prompt on the only line."""
+ out = _render_text("hello")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
+ assert "hello" in out[0]
+
+
+def test_composer_multiline_one_line_per_logical_line():
+ """Multi-line text renders one Line per logical line (rant 14:25:55)."""
+ out = _render_text("line1\nline2\nline3")
+ assert len(out) == 3
+ assert out[0].startswith("> ")
+ assert out[0][2:].strip().startswith("line1")
+ # Continuation lines: same-width indent, no prompt symbol
+ assert out[1].startswith(" ")
+ assert out[1].lstrip().startswith("line2")
+ assert out[2].startswith(" ")
+ assert out[2].lstrip().startswith("line3")
+
+
+def test_composer_multiline_no_prompt_on_continuation():
+ """Only the first line carries '> '; continuation uses indent only."""
+ out = _render_text("a\nb")
+ assert out[0].startswith("> ")
+ assert out[1].startswith(" ")
+ assert not out[1].lstrip().startswith(">")
+ assert out[1].strip() == "b"
+
+
+def test_composer_cursor_mid_first_line():
+ """Cursor in the middle of the first line is drawn there."""
+ composer = Composer()
+ composer._text = "abcd\nef"
+ composer._cursor = 2 # between 'ab' and 'cd'
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ first = "".join(s.text for s in lines[0].spans)
+ # prompt '> ' + prefix 'ab' + cursor 'c' + suffix 'd'
+ assert first == "> abcd"
+ assert lines[0].spans[2].text == "c" # the cursor span
+
+
+def test_composer_cursor_on_second_line():
+ """Cursor on a continuation line is drawn there, first line stays plain."""
+ composer = Composer()
+ composer._text = "ab\ncdef"
+ composer._cursor = 3 + 1 # 'a'=0,'b'=1,'\n'=2,'c'=3 → cursor at 'd' (idx 4? no)
+ # offsets: a0 b1 \n2 c3 d4 e5 f6 → cursor 4 = 'd'
+ composer._cursor = 4
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ second = "".join(s.text for s in lines[1].spans)
+ # prefix 'c' + cursor 'd' + suffix 'ef'
+ assert second.lstrip().startswith("cd")
+
+
+def test_composer_empty_placeholder():
+ """Empty composer renders a single dim prompt line."""
+ out = _render_text("")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
diff --git a/tests/test_user_markdown.py b/tests/test_user_markdown.py
@@ -100,3 +100,42 @@ def test_chat_history_update_last_updates_user_markdown():
  chat.update_last("updated text")
  assert isinstance(chat.rows[0], UserMarkdown)
  assert chat.rows[0].text == "updated text"
+
+
+def test_user_markdown_preserves_single_newlines():
+ """Pasted multi-line text keeps its line breaks (rant 2026-08-19T14:25:55).
+
+ RichMarkdown would collapse single \\n into spaces; the hard-break
+ preprocessing must keep each logical line separate with "> " only on
+ the first line and a same-width indent on continuation lines.
+ """
+ visible = _render("line1\nline2\nline3", 40)
+ assert len(visible) == 3
+ assert visible[0].startswith("> ")
+ assert "line1" in visible[0]
+ assert visible[1].startswith(" ")
+ assert "line2" in visible[1]
+ assert visible[2].startswith(" ")
+ assert "line3" in visible[2]
+
+
+def test_user_markdown_preserves_blank_lines_as_paragraphs():
+ """Blank lines still act as paragraph separators (\\n\\n unchanged)."""
+ visible = _render("para one\n\npara two", 40)
+ # two paragraphs → at least 2 rendered lines, second starts fresh
+ assert len(visible) >= 2
+ assert "para one" in visible[0]
+ assert "para two" in visible[-1]
+
+
+def test_preserve_line_breaks_skips_fenced_code_blocks():
+ """Lines inside ``` fences are not given trailing hard-break spaces."""
+ from emrg.client.python_tui.widgets.markdown import _preserve_line_breaks
+
+ text = "intro\n```\ncode line 1\ncode line 2\n```\noutro"
+ out = _preserve_line_breaks(text)
+ parts = out.split("\n")
+ assert parts[0] == "intro " # plain line → hard break
+ assert parts[2] == "code line 1" # fence interior untouched
+ assert parts[3] == "code line 2"
+ assert parts[5] == "outro "
diff --git a/Agent.md b/Agent.md
@@ -118,7 +118,7 @@ Community needs voiced in HN agent-UI discussions map directly to EMRG's design:
 pkill -f "emrg.server"; rm -f ~/.emrg/emrgd.port; python -m emrg
 ```
 
-Python: `uv run pytest tests/ -v` (968) — import check: `uv run python -c "from emrg.client.app import run_client"`
+Python: `uv run pytest tests/ -v` (977) — import check: `uv run python -c "from emrg.client.app import run_client"`
 GUI: `cd emrg/gui && npm test` (260: 45 daemon_client + 19 conn-manager + 22 app-commands + 131 renderer smoke + 16 i18n + 7 integration + 3 commands + 8 build-config + 7 gui-state + 2 tool-group) — syntax: `node --check main.js preload.js daemon_client.js renderer/js/*.js`
 CI: `uv run pytest` (ubuntu + **windows-2025 matrix** — Windows pytest 回归在 PR CI 即失败，v0.2.29 教训 #725) + GUI tests + **actionlint workflow lint** (`rhysd/actionlint@v1.7.12` gate, #444 — workflow 解析错误在 PR CI 即失败，如 `if:` secrets 上下文)
 Re-trigger: `scripts/re-trigger-ci.sh [branch]` (workflow_dispatch, #527 — 替代空 commit 重触发：Actions outage 会整段丢弃 push 事件，dispatch 走 API 路径不受影响)

diff --git a/emrg/client/python_tui/widgets/composer.py b/emrg/client/python_tui/widgets/composer.py
@@ -140,28 +140,55 @@ def submit(self) -> str | None:
  return text
 
  def render(self, ctx: RenderContext) -> list[Line]:
- """Render the composer with prompt, text, and cursor indicator."""
+ """Render the composer with prompt, text, and cursor indicator.
+
+ Multi-line text (pasted input) renders as one Line per logical line:
+ the first line carries the prompt, continuation lines a same-width
+ indent, and the cursor is drawn on the line it currently sits in
+ (rant 2026-08-19T14:25:55 — a single Line with embedded ``\\n`` was
+ flattened by the buffer, which skips newline characters).
+ """
  is_placeholder = not self._text
 
- # Show cursor position
- if self._text and self._cursor < len(self._text):
- cursor_char = self._text[self._cursor]
- prefix = self._text[:self._cursor]
- suffix = self._text[self._cursor + 1:]
- else:
- cursor_char = " "
- prefix = self._text
- suffix = ""
-
- cursor_style = "reverse" if self._text else "dim"
- style = "dim" if is_placeholder else ""
-
+ if self._text:
+ content_lines = self._text.split("\n")
+ indent = " " * len(self.prompt)
+ lines_out: list[Line] = []
+ line_start = 0
+ for i, line_text in enumerate(content_lines):
+ line_end = line_start + len(line_text)
+ # Cursor lives in this line iff it is within [line_start, line_end].
+ cursor_here = line_start <= self._cursor <= line_end
+ if cursor_here:
+ rel = self._cursor - line_start
+ if rel < len(line_text):
+ cursor_char = line_text[rel]
+ prefix = line_text[:rel]
+ suffix = line_text[rel + 1:]
+ else: # cursor at end of this line (incl. on the newline)
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ else:
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ lines_out.append(Line(spans=[
+ Span(text=self.prompt if i == 0 else indent,
+ style="bold cyan" if i == 0 else "dim"),
+ Span(text=prefix, style="" if not is_placeholder else "dim"),
+ Span(text=cursor_char, style="reverse"),
+ Span(text=suffix, style="" if not is_placeholder else "dim"),
+ ], style=ctx.style))
+ line_start = line_end + 1 # skip the newline separator
+ self._dirty = False
+ return lines_out
+
+ # Empty / placeholder: single line with prompt + dim cursor block.
  spans = [
  Span(text=self.prompt, style="bold cyan"),
- Span(text=prefix, style=style),
- Span(text=cursor_char, style=cursor_style),
- Span(text=suffix, style=style),
+ Span(text=" ", style="dim"),
+ Span(text=" ", style="dim"),
  ]
-
  self._dirty = False
  return [Line(spans=spans, style=ctx.style)]
diff --git a/emrg/client/python_tui/widgets/markdown.py b/emrg/client/python_tui/widgets/markdown.py
@@ -56,6 +56,10 @@ class UserMarkdown(Markdown):
  ``> `` prefix + bold cyan role visual. The markdown is rendered at
  ``ctx.width - len(prefix)`` so the prefix on the first line never
  overflows the buffer width (continuation lines get a same-width indent).
+
+ Single newlines are preserved as hard line breaks (rant
+ 2026-08-19T14:25:55): Rich would otherwise collapse ``\\n`` into a
+ space, merging pasted multi-line messages into one wrapped line.
  """
 
  _ROLE_PREFIX = "> "
@@ -72,7 +76,7 @@ def render(self, ctx: RenderContext) -> list[Line]:
  role_style = Style.parse(self._ROLE_STYLE)
  avail = max(1, ctx.width - len(prefix))
 
- md = RichMarkdown(self.text, code_theme="monokai")
+ md = RichMarkdown(_preserve_line_breaks(self.text), code_theme="monokai")
  md_lines = rich_renderable_to_lines(md, avail)
  lines: list[Line] = []
  for i, line in enumerate(md_lines):
@@ -84,6 +88,29 @@ def render(self, ctx: RenderContext) -> list[Line]:
  return lines
 
 
+def _preserve_line_breaks(text: str) -> str:
+ """Turn single newlines into hard breaks so RichMarkdown keeps them.
+
+ Rich collapses a single ``\\n`` (markdown soft break) into a space, so
+ pasted multi-line user messages render as one long auto-wrapped line.
+ A CommonMark hard break is a line ending in two spaces — Rich renders
+ each such line separately. Blank lines (paragraph separators) and the
+ interior of fenced code blocks are left untouched: trailing whitespace
+ is significant inside code blocks.
+ """
+ out: list[str] = []
+ in_fence = False
+ for line in text.split("\n"):
+ if line.lstrip().startswith("```"):
+ in_fence = not in_fence
+ out.append(line)
+ elif in_fence or not line.strip():
+ out.append(line)
+ else:
+ out.append(line + " ")
+ return "\n".join(out)
+
+
 @dataclass
 class StreamingMarkdown(Widget):
  """Incremental markdown renderer for token-by-token streaming.

diff --git a/tests/test_composer.py b/tests/test_composer.py
@@ -0,0 +1,87 @@
+"""Tests for the Composer widget (multi-line input rendering).
+
+rant 2026-08-19T14:25:55: pasted multi-line text must render as one line
+per logical line — the first line carries the prompt, continuation lines a
+same-width indent, and the cursor is drawn on the line it currently sits
+in. (The old single-Line render was flattened by the buffer, which skips
+\\n characters → long auto-wrapped blob.)
+"""
+
+from __future__ import annotations
+
+from emrg.client.python_tui.widgets.base import RenderContext
+from emrg.client.python_tui.widgets.composer import Composer
+
+
+def _render_text(text: str, cursor: int | None = None) -> list[str]:
+ composer = Composer()
+ if text:
+ composer._text = text
+ composer._cursor = len(text) if cursor is None else cursor
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ return ["".join(s.text for s in line.spans) for line in lines]
+
+
+def test_composer_single_line():
+ """Single-line input keeps the prompt on the only line."""
+ out = _render_text("hello")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
+ assert "hello" in out[0]
+
+
+def test_composer_multiline_one_line_per_logical_line():
+ """Multi-line text renders one Line per logical line (rant 14:25:55)."""
+ out = _render_text("line1\nline2\nline3")
+ assert len(out) == 3
+ assert out[0].startswith("> ")
+ assert out[0][2:].strip().startswith("line1")
+ # Continuation lines: same-width indent, no prompt symbol
+ assert out[1].startswith(" ")
+ assert out[1].lstrip().startswith("line2")
+ assert out[2].startswith(" ")
+ assert out[2].lstrip().startswith("line3")
+
+
+def test_composer_multiline_no_prompt_on_continuation():
+ """Only the first line carries '> '; continuation uses indent only."""
+ out = _render_text("a\nb")
+ assert out[0].startswith("> ")
+ assert out[1].startswith(" ")
+ assert not out[1].lstrip().startswith(">")
+ assert out[1].strip() == "b"
+
+
+def test_composer_cursor_mid_first_line():
+ """Cursor in the middle of the first line is drawn there."""
+ composer = Composer()
+ composer._text = "abcd\nef"
+ composer._cursor = 2 # between 'ab' and 'cd'
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ first = "".join(s.text for s in lines[0].spans)
+ # prompt '> ' + prefix 'ab' + cursor 'c' + suffix 'd'
+ assert first == "> abcd"
+ assert lines[0].spans[2].text == "c" # the cursor span
+
+
+def test_composer_cursor_on_second_line():
+ """Cursor on a continuation line is drawn there, first line stays plain."""
+ composer = Composer()
+ composer._text = "ab\ncdef"
+ composer._cursor = 3 + 1 # 'a'=0,'b'=1,'\n'=2,'c'=3 → cursor at 'd' (idx 4? no)
+ # offsets: a0 b1 \n2 c3 d4 e5 f6 → cursor 4 = 'd'
+ composer._cursor = 4
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ second = "".join(s.text for s in lines[1].spans)
+ # prefix 'c' + cursor 'd' + suffix 'ef'
+ assert second.lstrip().startswith("cd")
+
+
+def test_composer_empty_placeholder():
+ """Empty composer renders a single dim prompt line."""
+ out = _render_text("")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
diff --git a/tests/test_user_markdown.py b/tests/test_user_markdown.py
@@ -100,3 +100,42 @@ def test_chat_history_update_last_updates_user_markdown():
  chat.update_last("updated text")
  assert isinstance(chat.rows[0], UserMarkdown)
  assert chat.rows[0].text == "updated text"
+
+
+def test_user_markdown_preserves_single_newlines():
+ """Pasted multi-line text keeps its line breaks (rant 2026-08-19T14:25:55).
+
+ RichMarkdown would collapse single \\n into spaces; the hard-break
+ preprocessing must keep each logical line separate with "> " only on
+ the first line and a same-width indent on continuation lines.
+ """
+ visible = _render("line1\nline2\nline3", 40)
+ assert len(visible) == 3
+ assert visible[0].startswith("> ")
+ assert "line1" in visible[0]
+ assert visible[1].startswith(" ")
+ assert "line2" in visible[1]
+ assert visible[2].startswith(" ")
+ assert "line3" in visible[2]
+
+
+def test_user_markdown_preserves_blank_lines_as_paragraphs():
+ """Blank lines still act as paragraph separators (\\n\\n unchanged)."""
+ visible = _render("para one\n\npara two", 40)
+ # two paragraphs → at least 2 rendered lines, second starts fresh
+ assert len(visible) >= 2
+ assert "para one" in visible[0]
+ assert "para two" in visible[-1]
+
+
+def test_preserve_line_breaks_skips_fenced_code_blocks():
+ """Lines inside ``` fences are not given trailing hard-break spaces."""
+ from emrg.client.python_tui.widgets.markdown import _preserve_line_breaks
+
+ text = "intro\n```\ncode line 1\ncode line 2\n```\noutro"
+ out = _preserve_line_breaks(text)
+ parts = out.split("\n")
+ assert parts[0] == "intro " # plain line → hard break
+ assert parts[2] == "code line 1" # fence interior untouched
+ assert parts[3] == "code line 2"
+ assert parts[5] == "outro "
diff --git a/Agent.md b/Agent.md
@@ -118,7 +118,7 @@ Community needs voiced in HN agent-UI discussions map directly to EMRG's design:
 pkill -f "emrg.server"; rm -f ~/.emrg/emrgd.port; python -m emrg
 ```
 
-Python: `uv run pytest tests/ -v` (968) — import check: `uv run python -c "from emrg.client.app import run_client"`
+Python: `uv run pytest tests/ -v` (977) — import check: `uv run python -c "from emrg.client.app import run_client"`
 GUI: `cd emrg/gui && npm test` (260: 45 daemon_client + 19 conn-manager + 22 app-commands + 131 renderer smoke + 16 i18n + 7 integration + 3 commands + 8 build-config + 7 gui-state + 2 tool-group) — syntax: `node --check main.js preload.js daemon_client.js renderer/js/*.js`
 CI: `uv run pytest` (ubuntu + **windows-2025 matrix** — Windows pytest 回归在 PR CI 即失败，v0.2.29 教训 #725) + GUI tests + **actionlint workflow lint** (`rhysd/actionlint@v1.7.12` gate, #444 — workflow 解析错误在 PR CI 即失败，如 `if:` secrets 上下文)
 Re-trigger: `scripts/re-trigger-ci.sh [branch]` (workflow_dispatch, #527 — 替代空 commit 重触发：Actions outage 会整段丢弃 push 事件，dispatch 走 API 路径不受影响)

diff --git a/emrg/client/python_tui/widgets/composer.py b/emrg/client/python_tui/widgets/composer.py
@@ -140,28 +140,55 @@ def submit(self) -> str | None:
  return text
 
  def render(self, ctx: RenderContext) -> list[Line]:
- """Render the composer with prompt, text, and cursor indicator."""
+ """Render the composer with prompt, text, and cursor indicator.
+
+ Multi-line text (pasted input) renders as one Line per logical line:
+ the first line carries the prompt, continuation lines a same-width
+ indent, and the cursor is drawn on the line it currently sits in
+ (rant 2026-08-19T14:25:55 — a single Line with embedded ``\\n`` was
+ flattened by the buffer, which skips newline characters).
+ """
  is_placeholder = not self._text
 
- # Show cursor position
- if self._text and self._cursor < len(self._text):
- cursor_char = self._text[self._cursor]
- prefix = self._text[:self._cursor]
- suffix = self._text[self._cursor + 1:]
- else:
- cursor_char = " "
- prefix = self._text
- suffix = ""
-
- cursor_style = "reverse" if self._text else "dim"
- style = "dim" if is_placeholder else ""
-
+ if self._text:
+ content_lines = self._text.split("\n")
+ indent = " " * len(self.prompt)
+ lines_out: list[Line] = []
+ line_start = 0
+ for i, line_text in enumerate(content_lines):
+ line_end = line_start + len(line_text)
+ # Cursor lives in this line iff it is within [line_start, line_end].
+ cursor_here = line_start <= self._cursor <= line_end
+ if cursor_here:
+ rel = self._cursor - line_start
+ if rel < len(line_text):
+ cursor_char = line_text[rel]
+ prefix = line_text[:rel]
+ suffix = line_text[rel + 1:]
+ else: # cursor at end of this line (incl. on the newline)
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ else:
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ lines_out.append(Line(spans=[
+ Span(text=self.prompt if i == 0 else indent,
+ style="bold cyan" if i == 0 else "dim"),
+ Span(text=prefix, style="" if not is_placeholder else "dim"),
+ Span(text=cursor_char, style="reverse"),
+ Span(text=suffix, style="" if not is_placeholder else "dim"),
+ ], style=ctx.style))
+ line_start = line_end + 1 # skip the newline separator
+ self._dirty = False
+ return lines_out
+
+ # Empty / placeholder: single line with prompt + dim cursor block.
  spans = [
  Span(text=self.prompt, style="bold cyan"),
- Span(text=prefix, style=style),
- Span(text=cursor_char, style=cursor_style),
- Span(text=suffix, style=style),
+ Span(text=" ", style="dim"),
+ Span(text=" ", style="dim"),
  ]
-
  self._dirty = False
  return [Line(spans=spans, style=ctx.style)]
diff --git a/emrg/client/python_tui/widgets/markdown.py b/emrg/client/python_tui/widgets/markdown.py
@@ -56,6 +56,10 @@ class UserMarkdown(Markdown):
  ``> `` prefix + bold cyan role visual. The markdown is rendered at
  ``ctx.width - len(prefix)`` so the prefix on the first line never
  overflows the buffer width (continuation lines get a same-width indent).
+
+ Single newlines are preserved as hard line breaks (rant
+ 2026-08-19T14:25:55): Rich would otherwise collapse ``\\n`` into a
+ space, merging pasted multi-line messages into one wrapped line.
  """
 
  _ROLE_PREFIX = "> "
@@ -72,7 +76,7 @@ def render(self, ctx: RenderContext) -> list[Line]:
  role_style = Style.parse(self._ROLE_STYLE)
  avail = max(1, ctx.width - len(prefix))
 
- md = RichMarkdown(self.text, code_theme="monokai")
+ md = RichMarkdown(_preserve_line_breaks(self.text), code_theme="monokai")
  md_lines = rich_renderable_to_lines(md, avail)
  lines: list[Line] = []
  for i, line in enumerate(md_lines):
@@ -84,6 +88,29 @@ def render(self, ctx: RenderContext) -> list[Line]:
  return lines
 
 
+def _preserve_line_breaks(text: str) -> str:
+ """Turn single newlines into hard breaks so RichMarkdown keeps them.
+
+ Rich collapses a single ``\\n`` (markdown soft break) into a space, so
+ pasted multi-line user messages render as one long auto-wrapped line.
+ A CommonMark hard break is a line ending in two spaces — Rich renders
+ each such line separately. Blank lines (paragraph separators) and the
+ interior of fenced code blocks are left untouched: trailing whitespace
+ is significant inside code blocks.
+ """
+ out: list[str] = []
+ in_fence = False
+ for line in text.split("\n"):
+ if line.lstrip().startswith("```"):
+ in_fence = not in_fence
+ out.append(line)
+ elif in_fence or not line.strip():
+ out.append(line)
+ else:
+ out.append(line + " ")
+ return "\n".join(out)
+
+
 @dataclass
 class StreamingMarkdown(Widget):
  """Incremental markdown renderer for token-by-token streaming.

diff --git a/tests/test_composer.py b/tests/test_composer.py
@@ -0,0 +1,87 @@
+"""Tests for the Composer widget (multi-line input rendering).
+
+rant 2026-08-19T14:25:55: pasted multi-line text must render as one line
+per logical line — the first line carries the prompt, continuation lines a
+same-width indent, and the cursor is drawn on the line it currently sits
+in. (The old single-Line render was flattened by the buffer, which skips
+\\n characters → long auto-wrapped blob.)
+"""
+
+from __future__ import annotations
+
+from emrg.client.python_tui.widgets.base import RenderContext
+from emrg.client.python_tui.widgets.composer import Composer
+
+
+def _render_text(text: str, cursor: int | None = None) -> list[str]:
+ composer = Composer()
+ if text:
+ composer._text = text
+ composer._cursor = len(text) if cursor is None else cursor
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ return ["".join(s.text for s in line.spans) for line in lines]
+
+
+def test_composer_single_line():
+ """Single-line input keeps the prompt on the only line."""
+ out = _render_text("hello")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
+ assert "hello" in out[0]
+
+
+def test_composer_multiline_one_line_per_logical_line():
+ """Multi-line text renders one Line per logical line (rant 14:25:55)."""
+ out = _render_text("line1\nline2\nline3")
+ assert len(out) == 3
+ assert out[0].startswith("> ")
+ assert out[0][2:].strip().startswith("line1")
+ # Continuation lines: same-width indent, no prompt symbol
+ assert out[1].startswith(" ")
+ assert out[1].lstrip().startswith("line2")
+ assert out[2].startswith(" ")
+ assert out[2].lstrip().startswith("line3")
+
+
+def test_composer_multiline_no_prompt_on_continuation():
+ """Only the first line carries '> '; continuation uses indent only."""
+ out = _render_text("a\nb")
+ assert out[0].startswith("> ")
+ assert out[1].startswith(" ")
+ assert not out[1].lstrip().startswith(">")
+ assert out[1].strip() == "b"
+
+
+def test_composer_cursor_mid_first_line():
+ """Cursor in the middle of the first line is drawn there."""
+ composer = Composer()
+ composer._text = "abcd\nef"
+ composer._cursor = 2 # between 'ab' and 'cd'
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ first = "".join(s.text for s in lines[0].spans)
+ # prompt '> ' + prefix 'ab' + cursor 'c' + suffix 'd'
+ assert first == "> abcd"
+ assert lines[0].spans[2].text == "c" # the cursor span
+
+
+def test_composer_cursor_on_second_line():
+ """Cursor on a continuation line is drawn there, first line stays plain."""
+ composer = Composer()
+ composer._text = "ab\ncdef"
+ composer._cursor = 3 + 1 # 'a'=0,'b'=1,'\n'=2,'c'=3 → cursor at 'd' (idx 4? no)
+ # offsets: a0 b1 \n2 c3 d4 e5 f6 → cursor 4 = 'd'
+ composer._cursor = 4
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ second = "".join(s.text for s in lines[1].spans)
+ # prefix 'c' + cursor 'd' + suffix 'ef'
+ assert second.lstrip().startswith("cd")
+
+
+def test_composer_empty_placeholder():
+ """Empty composer renders a single dim prompt line."""
+ out = _render_text("")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
diff --git a/tests/test_user_markdown.py b/tests/test_user_markdown.py
@@ -100,3 +100,42 @@ def test_chat_history_update_last_updates_user_markdown():
  chat.update_last("updated text")
  assert isinstance(chat.rows[0], UserMarkdown)
  assert chat.rows[0].text == "updated text"
+
+
+def test_user_markdown_preserves_single_newlines():
+ """Pasted multi-line text keeps its line breaks (rant 2026-08-19T14:25:55).
+
+ RichMarkdown would collapse single \\n into spaces; the hard-break
+ preprocessing must keep each logical line separate with "> " only on
+ the first line and a same-width indent on continuation lines.
+ """
+ visible = _render("line1\nline2\nline3", 40)
+ assert len(visible) == 3
+ assert visible[0].startswith("> ")
+ assert "line1" in visible[0]
+ assert visible[1].startswith(" ")
+ assert "line2" in visible[1]
+ assert visible[2].startswith(" ")
+ assert "line3" in visible[2]
+
+
+def test_user_markdown_preserves_blank_lines_as_paragraphs():
+ """Blank lines still act as paragraph separators (\\n\\n unchanged)."""
+ visible = _render("para one\n\npara two", 40)
+ # two paragraphs → at least 2 rendered lines, second starts fresh
+ assert len(visible) >= 2
+ assert "para one" in visible[0]
+ assert "para two" in visible[-1]
+
+
+def test_preserve_line_breaks_skips_fenced_code_blocks():
+ """Lines inside ``` fences are not given trailing hard-break spaces."""
+ from emrg.client.python_tui.widgets.markdown import _preserve_line_breaks
+
+ text = "intro\n```\ncode line 1\ncode line 2\n```\noutro"
+ out = _preserve_line_breaks(text)
+ parts = out.split("\n")
+ assert parts[0] == "intro " # plain line → hard break
+ assert parts[2] == "code line 1" # fence interior untouched
+ assert parts[3] == "code line 2"
+ assert parts[5] == "outro "
diff --git a/Agent.md b/Agent.md
@@ -118,7 +118,7 @@ Community needs voiced in HN agent-UI discussions map directly to EMRG's design:
 pkill -f "emrg.server"; rm -f ~/.emrg/emrgd.port; python -m emrg
 ```
 
-Python: `uv run pytest tests/ -v` (968) — import check: `uv run python -c "from emrg.client.app import run_client"`
+Python: `uv run pytest tests/ -v` (977) — import check: `uv run python -c "from emrg.client.app import run_client"`
 GUI: `cd emrg/gui && npm test` (260: 45 daemon_client + 19 conn-manager + 22 app-commands + 131 renderer smoke + 16 i18n + 7 integration + 3 commands + 8 build-config + 7 gui-state + 2 tool-group) — syntax: `node --check main.js preload.js daemon_client.js renderer/js/*.js`
 CI: `uv run pytest` (ubuntu + **windows-2025 matrix** — Windows pytest 回归在 PR CI 即失败，v0.2.29 教训 #725) + GUI tests + **actionlint workflow lint** (`rhysd/actionlint@v1.7.12` gate, #444 — workflow 解析错误在 PR CI 即失败，如 `if:` secrets 上下文)
 Re-trigger: `scripts/re-trigger-ci.sh [branch]` (workflow_dispatch, #527 — 替代空 commit 重触发：Actions outage 会整段丢弃 push 事件，dispatch 走 API 路径不受影响)

diff --git a/emrg/client/python_tui/widgets/composer.py b/emrg/client/python_tui/widgets/composer.py
@@ -140,28 +140,55 @@ def submit(self) -> str | None:
  return text
 
  def render(self, ctx: RenderContext) -> list[Line]:
- """Render the composer with prompt, text, and cursor indicator."""
+ """Render the composer with prompt, text, and cursor indicator.
+
+ Multi-line text (pasted input) renders as one Line per logical line:
+ the first line carries the prompt, continuation lines a same-width
+ indent, and the cursor is drawn on the line it currently sits in
+ (rant 2026-08-19T14:25:55 — a single Line with embedded ``\\n`` was
+ flattened by the buffer, which skips newline characters).
+ """
  is_placeholder = not self._text
 
- # Show cursor position
- if self._text and self._cursor < len(self._text):
- cursor_char = self._text[self._cursor]
- prefix = self._text[:self._cursor]
- suffix = self._text[self._cursor + 1:]
- else:
- cursor_char = " "
- prefix = self._text
- suffix = ""
-
- cursor_style = "reverse" if self._text else "dim"
- style = "dim" if is_placeholder else ""
-
+ if self._text:
+ content_lines = self._text.split("\n")
+ indent = " " * len(self.prompt)
+ lines_out: list[Line] = []
+ line_start = 0
+ for i, line_text in enumerate(content_lines):
+ line_end = line_start + len(line_text)
+ # Cursor lives in this line iff it is within [line_start, line_end].
+ cursor_here = line_start <= self._cursor <= line_end
+ if cursor_here:
+ rel = self._cursor - line_start
+ if rel < len(line_text):
+ cursor_char = line_text[rel]
+ prefix = line_text[:rel]
+ suffix = line_text[rel + 1:]
+ else: # cursor at end of this line (incl. on the newline)
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ else:
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ lines_out.append(Line(spans=[
+ Span(text=self.prompt if i == 0 else indent,
+ style="bold cyan" if i == 0 else "dim"),
+ Span(text=prefix, style="" if not is_placeholder else "dim"),
+ Span(text=cursor_char, style="reverse"),
+ Span(text=suffix, style="" if not is_placeholder else "dim"),
+ ], style=ctx.style))
+ line_start = line_end + 1 # skip the newline separator
+ self._dirty = False
+ return lines_out
+
+ # Empty / placeholder: single line with prompt + dim cursor block.
  spans = [
  Span(text=self.prompt, style="bold cyan"),
- Span(text=prefix, style=style),
- Span(text=cursor_char, style=cursor_style),
- Span(text=suffix, style=style),
+ Span(text=" ", style="dim"),
+ Span(text=" ", style="dim"),
  ]
-
  self._dirty = False
  return [Line(spans=spans, style=ctx.style)]
diff --git a/emrg/client/python_tui/widgets/markdown.py b/emrg/client/python_tui/widgets/markdown.py
@@ -56,6 +56,10 @@ class UserMarkdown(Markdown):
  ``> `` prefix + bold cyan role visual. The markdown is rendered at
  ``ctx.width - len(prefix)`` so the prefix on the first line never
  overflows the buffer width (continuation lines get a same-width indent).
+
+ Single newlines are preserved as hard line breaks (rant
+ 2026-08-19T14:25:55): Rich would otherwise collapse ``\\n`` into a
+ space, merging pasted multi-line messages into one wrapped line.
  """
 
  _ROLE_PREFIX = "> "
@@ -72,7 +76,7 @@ def render(self, ctx: RenderContext) -> list[Line]:
  role_style = Style.parse(self._ROLE_STYLE)
  avail = max(1, ctx.width - len(prefix))
 
- md = RichMarkdown(self.text, code_theme="monokai")
+ md = RichMarkdown(_preserve_line_breaks(self.text), code_theme="monokai")
  md_lines = rich_renderable_to_lines(md, avail)
  lines: list[Line] = []
  for i, line in enumerate(md_lines):
@@ -84,6 +88,29 @@ def render(self, ctx: RenderContext) -> list[Line]:
  return lines
 
 
+def _preserve_line_breaks(text: str) -> str:
+ """Turn single newlines into hard breaks so RichMarkdown keeps them.
+
+ Rich collapses a single ``\\n`` (markdown soft break) into a space, so
+ pasted multi-line user messages render as one long auto-wrapped line.
+ A CommonMark hard break is a line ending in two spaces — Rich renders
+ each such line separately. Blank lines (paragraph separators) and the
+ interior of fenced code blocks are left untouched: trailing whitespace
+ is significant inside code blocks.
+ """
+ out: list[str] = []
+ in_fence = False
+ for line in text.split("\n"):
+ if line.lstrip().startswith("```"):
+ in_fence = not in_fence
+ out.append(line)
+ elif in_fence or not line.strip():
+ out.append(line)
+ else:
+ out.append(line + " ")
+ return "\n".join(out)
+
+
 @dataclass
 class StreamingMarkdown(Widget):
  """Incremental markdown renderer for token-by-token streaming.

diff --git a/tests/test_composer.py b/tests/test_composer.py
@@ -0,0 +1,87 @@
+"""Tests for the Composer widget (multi-line input rendering).
+
+rant 2026-08-19T14:25:55: pasted multi-line text must render as one line
+per logical line — the first line carries the prompt, continuation lines a
+same-width indent, and the cursor is drawn on the line it currently sits
+in. (The old single-Line render was flattened by the buffer, which skips
+\\n characters → long auto-wrapped blob.)
+"""
+
+from __future__ import annotations
+
+from emrg.client.python_tui.widgets.base import RenderContext
+from emrg.client.python_tui.widgets.composer import Composer
+
+
+def _render_text(text: str, cursor: int | None = None) -> list[str]:
+ composer = Composer()
+ if text:
+ composer._text = text
+ composer._cursor = len(text) if cursor is None else cursor
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ return ["".join(s.text for s in line.spans) for line in lines]
+
+
+def test_composer_single_line():
+ """Single-line input keeps the prompt on the only line."""
+ out = _render_text("hello")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
+ assert "hello" in out[0]
+
+
+def test_composer_multiline_one_line_per_logical_line():
+ """Multi-line text renders one Line per logical line (rant 14:25:55)."""
+ out = _render_text("line1\nline2\nline3")
+ assert len(out) == 3
+ assert out[0].startswith("> ")
+ assert out[0][2:].strip().startswith("line1")
+ # Continuation lines: same-width indent, no prompt symbol
+ assert out[1].startswith(" ")
+ assert out[1].lstrip().startswith("line2")
+ assert out[2].startswith(" ")
+ assert out[2].lstrip().startswith("line3")
+
+
+def test_composer_multiline_no_prompt_on_continuation():
+ """Only the first line carries '> '; continuation uses indent only."""
+ out = _render_text("a\nb")
+ assert out[0].startswith("> ")
+ assert out[1].startswith(" ")
+ assert not out[1].lstrip().startswith(">")
+ assert out[1].strip() == "b"
+
+
+def test_composer_cursor_mid_first_line():
+ """Cursor in the middle of the first line is drawn there."""
+ composer = Composer()
+ composer._text = "abcd\nef"
+ composer._cursor = 2 # between 'ab' and 'cd'
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ first = "".join(s.text for s in lines[0].spans)
+ # prompt '> ' + prefix 'ab' + cursor 'c' + suffix 'd'
+ assert first == "> abcd"
+ assert lines[0].spans[2].text == "c" # the cursor span
+
+
+def test_composer_cursor_on_second_line():
+ """Cursor on a continuation line is drawn there, first line stays plain."""
+ composer = Composer()
+ composer._text = "ab\ncdef"
+ composer._cursor = 3 + 1 # 'a'=0,'b'=1,'\n'=2,'c'=3 → cursor at 'd' (idx 4? no)
+ # offsets: a0 b1 \n2 c3 d4 e5 f6 → cursor 4 = 'd'
+ composer._cursor = 4
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ second = "".join(s.text for s in lines[1].spans)
+ # prefix 'c' + cursor 'd' + suffix 'ef'
+ assert second.lstrip().startswith("cd")
+
+
+def test_composer_empty_placeholder():
+ """Empty composer renders a single dim prompt line."""
+ out = _render_text("")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
diff --git a/tests/test_user_markdown.py b/tests/test_user_markdown.py
@@ -100,3 +100,42 @@ def test_chat_history_update_last_updates_user_markdown():
  chat.update_last("updated text")
  assert isinstance(chat.rows[0], UserMarkdown)
  assert chat.rows[0].text == "updated text"
+
+
+def test_user_markdown_preserves_single_newlines():
+ """Pasted multi-line text keeps its line breaks (rant 2026-08-19T14:25:55).
+
+ RichMarkdown would collapse single \\n into spaces; the hard-break
+ preprocessing must keep each logical line separate with "> " only on
+ the first line and a same-width indent on continuation lines.
+ """
+ visible = _render("line1\nline2\nline3", 40)
+ assert len(visible) == 3
+ assert visible[0].startswith("> ")
+ assert "line1" in visible[0]
+ assert visible[1].startswith(" ")
+ assert "line2" in visible[1]
+ assert visible[2].startswith(" ")
+ assert "line3" in visible[2]
+
+
+def test_user_markdown_preserves_blank_lines_as_paragraphs():
+ """Blank lines still act as paragraph separators (\\n\\n unchanged)."""
+ visible = _render("para one\n\npara two", 40)
+ # two paragraphs → at least 2 rendered lines, second starts fresh
+ assert len(visible) >= 2
+ assert "para one" in visible[0]
+ assert "para two" in visible[-1]
+
+
+def test_preserve_line_breaks_skips_fenced_code_blocks():
+ """Lines inside ``` fences are not given trailing hard-break spaces."""
+ from emrg.client.python_tui.widgets.markdown import _preserve_line_breaks
+
+ text = "intro\n```\ncode line 1\ncode line 2\n```\noutro"
+ out = _preserve_line_breaks(text)
+ parts = out.split("\n")
+ assert parts[0] == "intro " # plain line → hard break
+ assert parts[2] == "code line 1" # fence interior untouched
+ assert parts[3] == "code line 2"
+ assert parts[5] == "outro "
diff --git a/Agent.md b/Agent.md
@@ -118,7 +118,7 @@ Community needs voiced in HN agent-UI discussions map directly to EMRG's design:
 pkill -f "emrg.server"; rm -f ~/.emrg/emrgd.port; python -m emrg
 ```
 
-Python: `uv run pytest tests/ -v` (968) — import check: `uv run python -c "from emrg.client.app import run_client"`
+Python: `uv run pytest tests/ -v` (977) — import check: `uv run python -c "from emrg.client.app import run_client"`
 GUI: `cd emrg/gui && npm test` (260: 45 daemon_client + 19 conn-manager + 22 app-commands + 131 renderer smoke + 16 i18n + 7 integration + 3 commands + 8 build-config + 7 gui-state + 2 tool-group) — syntax: `node --check main.js preload.js daemon_client.js renderer/js/*.js`
 CI: `uv run pytest` (ubuntu + **windows-2025 matrix** — Windows pytest 回归在 PR CI 即失败，v0.2.29 教训 #725) + GUI tests + **actionlint workflow lint** (`rhysd/actionlint@v1.7.12` gate, #444 — workflow 解析错误在 PR CI 即失败，如 `if:` secrets 上下文)
 Re-trigger: `scripts/re-trigger-ci.sh [branch]` (workflow_dispatch, #527 — 替代空 commit 重触发：Actions outage 会整段丢弃 push 事件，dispatch 走 API 路径不受影响)

diff --git a/emrg/client/python_tui/widgets/composer.py b/emrg/client/python_tui/widgets/composer.py
@@ -140,28 +140,55 @@ def submit(self) -> str | None:
  return text
 
  def render(self, ctx: RenderContext) -> list[Line]:
- """Render the composer with prompt, text, and cursor indicator."""
+ """Render the composer with prompt, text, and cursor indicator.
+
+ Multi-line text (pasted input) renders as one Line per logical line:
+ the first line carries the prompt, continuation lines a same-width
+ indent, and the cursor is drawn on the line it currently sits in
+ (rant 2026-08-19T14:25:55 — a single Line with embedded ``\\n`` was
+ flattened by the buffer, which skips newline characters).
+ """
  is_placeholder = not self._text
 
- # Show cursor position
- if self._text and self._cursor < len(self._text):
- cursor_char = self._text[self._cursor]
- prefix = self._text[:self._cursor]
- suffix = self._text[self._cursor + 1:]
- else:
- cursor_char = " "
- prefix = self._text
- suffix = ""
-
- cursor_style = "reverse" if self._text else "dim"
- style = "dim" if is_placeholder else ""
-
+ if self._text:
+ content_lines = self._text.split("\n")
+ indent = " " * len(self.prompt)
+ lines_out: list[Line] = []
+ line_start = 0
+ for i, line_text in enumerate(content_lines):
+ line_end = line_start + len(line_text)
+ # Cursor lives in this line iff it is within [line_start, line_end].
+ cursor_here = line_start <= self._cursor <= line_end
+ if cursor_here:
+ rel = self._cursor - line_start
+ if rel < len(line_text):
+ cursor_char = line_text[rel]
+ prefix = line_text[:rel]
+ suffix = line_text[rel + 1:]
+ else: # cursor at end of this line (incl. on the newline)
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ else:
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ lines_out.append(Line(spans=[
+ Span(text=self.prompt if i == 0 else indent,
+ style="bold cyan" if i == 0 else "dim"),
+ Span(text=prefix, style="" if not is_placeholder else "dim"),
+ Span(text=cursor_char, style="reverse"),
+ Span(text=suffix, style="" if not is_placeholder else "dim"),
+ ], style=ctx.style))
+ line_start = line_end + 1 # skip the newline separator
+ self._dirty = False
+ return lines_out
+
+ # Empty / placeholder: single line with prompt + dim cursor block.
  spans = [
  Span(text=self.prompt, style="bold cyan"),
- Span(text=prefix, style=style),
- Span(text=cursor_char, style=cursor_style),
- Span(text=suffix, style=style),
+ Span(text=" ", style="dim"),
+ Span(text=" ", style="dim"),
  ]
-
  self._dirty = False
  return [Line(spans=spans, style=ctx.style)]
diff --git a/emrg/client/python_tui/widgets/markdown.py b/emrg/client/python_tui/widgets/markdown.py
@@ -56,6 +56,10 @@ class UserMarkdown(Markdown):
  ``> `` prefix + bold cyan role visual. The markdown is rendered at
  ``ctx.width - len(prefix)`` so the prefix on the first line never
  overflows the buffer width (continuation lines get a same-width indent).
+
+ Single newlines are preserved as hard line breaks (rant
+ 2026-08-19T14:25:55): Rich would otherwise collapse ``\\n`` into a
+ space, merging pasted multi-line messages into one wrapped line.
  """
 
  _ROLE_PREFIX = "> "
@@ -72,7 +76,7 @@ def render(self, ctx: RenderContext) -> list[Line]:
  role_style = Style.parse(self._ROLE_STYLE)
  avail = max(1, ctx.width - len(prefix))
 
- md = RichMarkdown(self.text, code_theme="monokai")
+ md = RichMarkdown(_preserve_line_breaks(self.text), code_theme="monokai")
  md_lines = rich_renderable_to_lines(md, avail)
  lines: list[Line] = []
  for i, line in enumerate(md_lines):
@@ -84,6 +88,29 @@ def render(self, ctx: RenderContext) -> list[Line]:
  return lines
 
 
+def _preserve_line_breaks(text: str) -> str:
+ """Turn single newlines into hard breaks so RichMarkdown keeps them.
+
+ Rich collapses a single ``\\n`` (markdown soft break) into a space, so
+ pasted multi-line user messages render as one long auto-wrapped line.
+ A CommonMark hard break is a line ending in two spaces — Rich renders
+ each such line separately. Blank lines (paragraph separators) and the
+ interior of fenced code blocks are left untouched: trailing whitespace
+ is significant inside code blocks.
+ """
+ out: list[str] = []
+ in_fence = False
+ for line in text.split("\n"):
+ if line.lstrip().startswith("```"):
+ in_fence = not in_fence
+ out.append(line)
+ elif in_fence or not line.strip():
+ out.append(line)
+ else:
+ out.append(line + " ")
+ return "\n".join(out)
+
+
 @dataclass
 class StreamingMarkdown(Widget):
  """Incremental markdown renderer for token-by-token streaming.

diff --git a/tests/test_composer.py b/tests/test_composer.py
@@ -0,0 +1,87 @@
+"""Tests for the Composer widget (multi-line input rendering).
+
+rant 2026-08-19T14:25:55: pasted multi-line text must render as one line
+per logical line — the first line carries the prompt, continuation lines a
+same-width indent, and the cursor is drawn on the line it currently sits
+in. (The old single-Line render was flattened by the buffer, which skips
+\\n characters → long auto-wrapped blob.)
+"""
+
+from __future__ import annotations
+
+from emrg.client.python_tui.widgets.base import RenderContext
+from emrg.client.python_tui.widgets.composer import Composer
+
+
+def _render_text(text: str, cursor: int | None = None) -> list[str]:
+ composer = Composer()
+ if text:
+ composer._text = text
+ composer._cursor = len(text) if cursor is None else cursor
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ return ["".join(s.text for s in line.spans) for line in lines]
+
+
+def test_composer_single_line():
+ """Single-line input keeps the prompt on the only line."""
+ out = _render_text("hello")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
+ assert "hello" in out[0]
+
+
+def test_composer_multiline_one_line_per_logical_line():
+ """Multi-line text renders one Line per logical line (rant 14:25:55)."""
+ out = _render_text("line1\nline2\nline3")
+ assert len(out) == 3
+ assert out[0].startswith("> ")
+ assert out[0][2:].strip().startswith("line1")
+ # Continuation lines: same-width indent, no prompt symbol
+ assert out[1].startswith(" ")
+ assert out[1].lstrip().startswith("line2")
+ assert out[2].startswith(" ")
+ assert out[2].lstrip().startswith("line3")
+
+
+def test_composer_multiline_no_prompt_on_continuation():
+ """Only the first line carries '> '; continuation uses indent only."""
+ out = _render_text("a\nb")
+ assert out[0].startswith("> ")
+ assert out[1].startswith(" ")
+ assert not out[1].lstrip().startswith(">")
+ assert out[1].strip() == "b"
+
+
+def test_composer_cursor_mid_first_line():
+ """Cursor in the middle of the first line is drawn there."""
+ composer = Composer()
+ composer._text = "abcd\nef"
+ composer._cursor = 2 # between 'ab' and 'cd'
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ first = "".join(s.text for s in lines[0].spans)
+ # prompt '> ' + prefix 'ab' + cursor 'c' + suffix 'd'
+ assert first == "> abcd"
+ assert lines[0].spans[2].text == "c" # the cursor span
+
+
+def test_composer_cursor_on_second_line():
+ """Cursor on a continuation line is drawn there, first line stays plain."""
+ composer = Composer()
+ composer._text = "ab\ncdef"
+ composer._cursor = 3 + 1 # 'a'=0,'b'=1,'\n'=2,'c'=3 → cursor at 'd' (idx 4? no)
+ # offsets: a0 b1 \n2 c3 d4 e5 f6 → cursor 4 = 'd'
+ composer._cursor = 4
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ second = "".join(s.text for s in lines[1].spans)
+ # prefix 'c' + cursor 'd' + suffix 'ef'
+ assert second.lstrip().startswith("cd")
+
+
+def test_composer_empty_placeholder():
+ """Empty composer renders a single dim prompt line."""
+ out = _render_text("")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
diff --git a/tests/test_user_markdown.py b/tests/test_user_markdown.py
@@ -100,3 +100,42 @@ def test_chat_history_update_last_updates_user_markdown():
  chat.update_last("updated text")
  assert isinstance(chat.rows[0], UserMarkdown)
  assert chat.rows[0].text == "updated text"
+
+
+def test_user_markdown_preserves_single_newlines():
+ """Pasted multi-line text keeps its line breaks (rant 2026-08-19T14:25:55).
+
+ RichMarkdown would collapse single \\n into spaces; the hard-break
+ preprocessing must keep each logical line separate with "> " only on
+ the first line and a same-width indent on continuation lines.
+ """
+ visible = _render("line1\nline2\nline3", 40)
+ assert len(visible) == 3
+ assert visible[0].startswith("> ")
+ assert "line1" in visible[0]
+ assert visible[1].startswith(" ")
+ assert "line2" in visible[1]
+ assert visible[2].startswith(" ")
+ assert "line3" in visible[2]
+
+
+def test_user_markdown_preserves_blank_lines_as_paragraphs():
+ """Blank lines still act as paragraph separators (\\n\\n unchanged)."""
+ visible = _render("para one\n\npara two", 40)
+ # two paragraphs → at least 2 rendered lines, second starts fresh
+ assert len(visible) >= 2
+ assert "para one" in visible[0]
+ assert "para two" in visible[-1]
+
+
+def test_preserve_line_breaks_skips_fenced_code_blocks():
+ """Lines inside ``` fences are not given trailing hard-break spaces."""
+ from emrg.client.python_tui.widgets.markdown import _preserve_line_breaks
+
+ text = "intro\n```\ncode line 1\ncode line 2\n```\noutro"
+ out = _preserve_line_breaks(text)
+ parts = out.split("\n")
+ assert parts[0] == "intro " # plain line → hard break
+ assert parts[2] == "code line 1" # fence interior untouched
+ assert parts[3] == "code line 2"
+ assert parts[5] == "outro "
diff --git a/Agent.md b/Agent.md
@@ -118,7 +118,7 @@ Community needs voiced in HN agent-UI discussions map directly to EMRG's design:
 pkill -f "emrg.server"; rm -f ~/.emrg/emrgd.port; python -m emrg
 ```
 
-Python: `uv run pytest tests/ -v` (968) — import check: `uv run python -c "from emrg.client.app import run_client"`
+Python: `uv run pytest tests/ -v` (977) — import check: `uv run python -c "from emrg.client.app import run_client"`
 GUI: `cd emrg/gui && npm test` (260: 45 daemon_client + 19 conn-manager + 22 app-commands + 131 renderer smoke + 16 i18n + 7 integration + 3 commands + 8 build-config + 7 gui-state + 2 tool-group) — syntax: `node --check main.js preload.js daemon_client.js renderer/js/*.js`
 CI: `uv run pytest` (ubuntu + **windows-2025 matrix** — Windows pytest 回归在 PR CI 即失败，v0.2.29 教训 #725) + GUI tests + **actionlint workflow lint** (`rhysd/actionlint@v1.7.12` gate, #444 — workflow 解析错误在 PR CI 即失败，如 `if:` secrets 上下文)
 Re-trigger: `scripts/re-trigger-ci.sh [branch]` (workflow_dispatch, #527 — 替代空 commit 重触发：Actions outage 会整段丢弃 push 事件，dispatch 走 API 路径不受影响)

diff --git a/emrg/client/python_tui/widgets/composer.py b/emrg/client/python_tui/widgets/composer.py
@@ -140,28 +140,55 @@ def submit(self) -> str | None:
  return text
 
  def render(self, ctx: RenderContext) -> list[Line]:
- """Render the composer with prompt, text, and cursor indicator."""
+ """Render the composer with prompt, text, and cursor indicator.
+
+ Multi-line text (pasted input) renders as one Line per logical line:
+ the first line carries the prompt, continuation lines a same-width
+ indent, and the cursor is drawn on the line it currently sits in
+ (rant 2026-08-19T14:25:55 — a single Line with embedded ``\\n`` was
+ flattened by the buffer, which skips newline characters).
+ """
  is_placeholder = not self._text
 
- # Show cursor position
- if self._text and self._cursor < len(self._text):
- cursor_char = self._text[self._cursor]
- prefix = self._text[:self._cursor]
- suffix = self._text[self._cursor + 1:]
- else:
- cursor_char = " "
- prefix = self._text
- suffix = ""
-
- cursor_style = "reverse" if self._text else "dim"
- style = "dim" if is_placeholder else ""
-
+ if self._text:
+ content_lines = self._text.split("\n")
+ indent = " " * len(self.prompt)
+ lines_out: list[Line] = []
+ line_start = 0
+ for i, line_text in enumerate(content_lines):
+ line_end = line_start + len(line_text)
+ # Cursor lives in this line iff it is within [line_start, line_end].
+ cursor_here = line_start <= self._cursor <= line_end
+ if cursor_here:
+ rel = self._cursor - line_start
+ if rel < len(line_text):
+ cursor_char = line_text[rel]
+ prefix = line_text[:rel]
+ suffix = line_text[rel + 1:]
+ else: # cursor at end of this line (incl. on the newline)
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ else:
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ lines_out.append(Line(spans=[
+ Span(text=self.prompt if i == 0 else indent,
+ style="bold cyan" if i == 0 else "dim"),
+ Span(text=prefix, style="" if not is_placeholder else "dim"),
+ Span(text=cursor_char, style="reverse"),
+ Span(text=suffix, style="" if not is_placeholder else "dim"),
+ ], style=ctx.style))
+ line_start = line_end + 1 # skip the newline separator
+ self._dirty = False
+ return lines_out
+
+ # Empty / placeholder: single line with prompt + dim cursor block.
  spans = [
  Span(text=self.prompt, style="bold cyan"),
- Span(text=prefix, style=style),
- Span(text=cursor_char, style=cursor_style),
- Span(text=suffix, style=style),
+ Span(text=" ", style="dim"),
+ Span(text=" ", style="dim"),
  ]
-
  self._dirty = False
  return [Line(spans=spans, style=ctx.style)]
diff --git a/emrg/client/python_tui/widgets/markdown.py b/emrg/client/python_tui/widgets/markdown.py
@@ -56,6 +56,10 @@ class UserMarkdown(Markdown):
  ``> `` prefix + bold cyan role visual. The markdown is rendered at
  ``ctx.width - len(prefix)`` so the prefix on the first line never
  overflows the buffer width (continuation lines get a same-width indent).
+
+ Single newlines are preserved as hard line breaks (rant
+ 2026-08-19T14:25:55): Rich would otherwise collapse ``\\n`` into a
+ space, merging pasted multi-line messages into one wrapped line.
  """
 
  _ROLE_PREFIX = "> "
@@ -72,7 +76,7 @@ def render(self, ctx: RenderContext) -> list[Line]:
  role_style = Style.parse(self._ROLE_STYLE)
  avail = max(1, ctx.width - len(prefix))
 
- md = RichMarkdown(self.text, code_theme="monokai")
+ md = RichMarkdown(_preserve_line_breaks(self.text), code_theme="monokai")
  md_lines = rich_renderable_to_lines(md, avail)
  lines: list[Line] = []
  for i, line in enumerate(md_lines):
@@ -84,6 +88,29 @@ def render(self, ctx: RenderContext) -> list[Line]:
  return lines
 
 
+def _preserve_line_breaks(text: str) -> str:
+ """Turn single newlines into hard breaks so RichMarkdown keeps them.
+
+ Rich collapses a single ``\\n`` (markdown soft break) into a space, so
+ pasted multi-line user messages render as one long auto-wrapped line.
+ A CommonMark hard break is a line ending in two spaces — Rich renders
+ each such line separately. Blank lines (paragraph separators) and the
+ interior of fenced code blocks are left untouched: trailing whitespace
+ is significant inside code blocks.
+ """
+ out: list[str] = []
+ in_fence = False
+ for line in text.split("\n"):
+ if line.lstrip().startswith("```"):
+ in_fence = not in_fence
+ out.append(line)
+ elif in_fence or not line.strip():
+ out.append(line)
+ else:
+ out.append(line + " ")
+ return "\n".join(out)
+
+
 @dataclass
 class StreamingMarkdown(Widget):
  """Incremental markdown renderer for token-by-token streaming.

diff --git a/tests/test_composer.py b/tests/test_composer.py
@@ -0,0 +1,87 @@
+"""Tests for the Composer widget (multi-line input rendering).
+
+rant 2026-08-19T14:25:55: pasted multi-line text must render as one line
+per logical line — the first line carries the prompt, continuation lines a
+same-width indent, and the cursor is drawn on the line it currently sits
+in. (The old single-Line render was flattened by the buffer, which skips
+\\n characters → long auto-wrapped blob.)
+"""
+
+from __future__ import annotations
+
+from emrg.client.python_tui.widgets.base import RenderContext
+from emrg.client.python_tui.widgets.composer import Composer
+
+
+def _render_text(text: str, cursor: int | None = None) -> list[str]:
+ composer = Composer()
+ if text:
+ composer._text = text
+ composer._cursor = len(text) if cursor is None else cursor
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ return ["".join(s.text for s in line.spans) for line in lines]
+
+
+def test_composer_single_line():
+ """Single-line input keeps the prompt on the only line."""
+ out = _render_text("hello")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
+ assert "hello" in out[0]
+
+
+def test_composer_multiline_one_line_per_logical_line():
+ """Multi-line text renders one Line per logical line (rant 14:25:55)."""
+ out = _render_text("line1\nline2\nline3")
+ assert len(out) == 3
+ assert out[0].startswith("> ")
+ assert out[0][2:].strip().startswith("line1")
+ # Continuation lines: same-width indent, no prompt symbol
+ assert out[1].startswith(" ")
+ assert out[1].lstrip().startswith("line2")
+ assert out[2].startswith(" ")
+ assert out[2].lstrip().startswith("line3")
+
+
+def test_composer_multiline_no_prompt_on_continuation():
+ """Only the first line carries '> '; continuation uses indent only."""
+ out = _render_text("a\nb")
+ assert out[0].startswith("> ")
+ assert out[1].startswith(" ")
+ assert not out[1].lstrip().startswith(">")
+ assert out[1].strip() == "b"
+
+
+def test_composer_cursor_mid_first_line():
+ """Cursor in the middle of the first line is drawn there."""
+ composer = Composer()
+ composer._text = "abcd\nef"
+ composer._cursor = 2 # between 'ab' and 'cd'
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ first = "".join(s.text for s in lines[0].spans)
+ # prompt '> ' + prefix 'ab' + cursor 'c' + suffix 'd'
+ assert first == "> abcd"
+ assert lines[0].spans[2].text == "c" # the cursor span
+
+
+def test_composer_cursor_on_second_line():
+ """Cursor on a continuation line is drawn there, first line stays plain."""
+ composer = Composer()
+ composer._text = "ab\ncdef"
+ composer._cursor = 3 + 1 # 'a'=0,'b'=1,'\n'=2,'c'=3 → cursor at 'd' (idx 4? no)
+ # offsets: a0 b1 \n2 c3 d4 e5 f6 → cursor 4 = 'd'
+ composer._cursor = 4
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ second = "".join(s.text for s in lines[1].spans)
+ # prefix 'c' + cursor 'd' + suffix 'ef'
+ assert second.lstrip().startswith("cd")
+
+
+def test_composer_empty_placeholder():
+ """Empty composer renders a single dim prompt line."""
+ out = _render_text("")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
diff --git a/tests/test_user_markdown.py b/tests/test_user_markdown.py
@@ -100,3 +100,42 @@ def test_chat_history_update_last_updates_user_markdown():
  chat.update_last("updated text")
  assert isinstance(chat.rows[0], UserMarkdown)
  assert chat.rows[0].text == "updated text"
+
+
+def test_user_markdown_preserves_single_newlines():
+ """Pasted multi-line text keeps its line breaks (rant 2026-08-19T14:25:55).
+
+ RichMarkdown would collapse single \\n into spaces; the hard-break
+ preprocessing must keep each logical line separate with "> " only on
+ the first line and a same-width indent on continuation lines.
+ """
+ visible = _render("line1\nline2\nline3", 40)
+ assert len(visible) == 3
+ assert visible[0].startswith("> ")
+ assert "line1" in visible[0]
+ assert visible[1].startswith(" ")
+ assert "line2" in visible[1]
+ assert visible[2].startswith(" ")
+ assert "line3" in visible[2]
+
+
+def test_user_markdown_preserves_blank_lines_as_paragraphs():
+ """Blank lines still act as paragraph separators (\\n\\n unchanged)."""
+ visible = _render("para one\n\npara two", 40)
+ # two paragraphs → at least 2 rendered lines, second starts fresh
+ assert len(visible) >= 2
+ assert "para one" in visible[0]
+ assert "para two" in visible[-1]
+
+
+def test_preserve_line_breaks_skips_fenced_code_blocks():
+ """Lines inside ``` fences are not given trailing hard-break spaces."""
+ from emrg.client.python_tui.widgets.markdown import _preserve_line_breaks
+
+ text = "intro\n```\ncode line 1\ncode line 2\n```\noutro"
+ out = _preserve_line_breaks(text)
+ parts = out.split("\n")
+ assert parts[0] == "intro " # plain line → hard break
+ assert parts[2] == "code line 1" # fence interior untouched
+ assert parts[3] == "code line 2"
+ assert parts[5] == "outro "
diff --git a/Agent.md b/Agent.md
@@ -118,7 +118,7 @@ Community needs voiced in HN agent-UI discussions map directly to EMRG's design:
 pkill -f "emrg.server"; rm -f ~/.emrg/emrgd.port; python -m emrg
 ```
 
-Python: `uv run pytest tests/ -v` (968) — import check: `uv run python -c "from emrg.client.app import run_client"`
+Python: `uv run pytest tests/ -v` (977) — import check: `uv run python -c "from emrg.client.app import run_client"`
 GUI: `cd emrg/gui && npm test` (260: 45 daemon_client + 19 conn-manager + 22 app-commands + 131 renderer smoke + 16 i18n + 7 integration + 3 commands + 8 build-config + 7 gui-state + 2 tool-group) — syntax: `node --check main.js preload.js daemon_client.js renderer/js/*.js`
 CI: `uv run pytest` (ubuntu + **windows-2025 matrix** — Windows pytest 回归在 PR CI 即失败，v0.2.29 教训 #725) + GUI tests + **actionlint workflow lint** (`rhysd/actionlint@v1.7.12` gate, #444 — workflow 解析错误在 PR CI 即失败，如 `if:` secrets 上下文)
 Re-trigger: `scripts/re-trigger-ci.sh [branch]` (workflow_dispatch, #527 — 替代空 commit 重触发：Actions outage 会整段丢弃 push 事件，dispatch 走 API 路径不受影响)

diff --git a/emrg/client/python_tui/widgets/composer.py b/emrg/client/python_tui/widgets/composer.py
@@ -140,28 +140,55 @@ def submit(self) -> str | None:
  return text
 
  def render(self, ctx: RenderContext) -> list[Line]:
- """Render the composer with prompt, text, and cursor indicator."""
+ """Render the composer with prompt, text, and cursor indicator.
+
+ Multi-line text (pasted input) renders as one Line per logical line:
+ the first line carries the prompt, continuation lines a same-width
+ indent, and the cursor is drawn on the line it currently sits in
+ (rant 2026-08-19T14:25:55 — a single Line with embedded ``\\n`` was
+ flattened by the buffer, which skips newline characters).
+ """
  is_placeholder = not self._text
 
- # Show cursor position
- if self._text and self._cursor < len(self._text):
- cursor_char = self._text[self._cursor]
- prefix = self._text[:self._cursor]
- suffix = self._text[self._cursor + 1:]
- else:
- cursor_char = " "
- prefix = self._text
- suffix = ""
-
- cursor_style = "reverse" if self._text else "dim"
- style = "dim" if is_placeholder else ""
-
+ if self._text:
+ content_lines = self._text.split("\n")
+ indent = " " * len(self.prompt)
+ lines_out: list[Line] = []
+ line_start = 0
+ for i, line_text in enumerate(content_lines):
+ line_end = line_start + len(line_text)
+ # Cursor lives in this line iff it is within [line_start, line_end].
+ cursor_here = line_start <= self._cursor <= line_end
+ if cursor_here:
+ rel = self._cursor - line_start
+ if rel < len(line_text):
+ cursor_char = line_text[rel]
+ prefix = line_text[:rel]
+ suffix = line_text[rel + 1:]
+ else: # cursor at end of this line (incl. on the newline)
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ else:
+ cursor_char = " "
+ prefix = line_text
+ suffix = ""
+ lines_out.append(Line(spans=[
+ Span(text=self.prompt if i == 0 else indent,
+ style="bold cyan" if i == 0 else "dim"),
+ Span(text=prefix, style="" if not is_placeholder else "dim"),
+ Span(text=cursor_char, style="reverse"),
+ Span(text=suffix, style="" if not is_placeholder else "dim"),
+ ], style=ctx.style))
+ line_start = line_end + 1 # skip the newline separator
+ self._dirty = False
+ return lines_out
+
+ # Empty / placeholder: single line with prompt + dim cursor block.
  spans = [
  Span(text=self.prompt, style="bold cyan"),
- Span(text=prefix, style=style),
- Span(text=cursor_char, style=cursor_style),
- Span(text=suffix, style=style),
+ Span(text=" ", style="dim"),
+ Span(text=" ", style="dim"),
  ]
-
  self._dirty = False
  return [Line(spans=spans, style=ctx.style)]
diff --git a/emrg/client/python_tui/widgets/markdown.py b/emrg/client/python_tui/widgets/markdown.py
@@ -56,6 +56,10 @@ class UserMarkdown(Markdown):
  ``> `` prefix + bold cyan role visual. The markdown is rendered at
  ``ctx.width - len(prefix)`` so the prefix on the first line never
  overflows the buffer width (continuation lines get a same-width indent).
+
+ Single newlines are preserved as hard line breaks (rant
+ 2026-08-19T14:25:55): Rich would otherwise collapse ``\\n`` into a
+ space, merging pasted multi-line messages into one wrapped line.
  """
 
  _ROLE_PREFIX = "> "
@@ -72,7 +76,7 @@ def render(self, ctx: RenderContext) -> list[Line]:
  role_style = Style.parse(self._ROLE_STYLE)
  avail = max(1, ctx.width - len(prefix))
 
- md = RichMarkdown(self.text, code_theme="monokai")
+ md = RichMarkdown(_preserve_line_breaks(self.text), code_theme="monokai")
  md_lines = rich_renderable_to_lines(md, avail)
  lines: list[Line] = []
  for i, line in enumerate(md_lines):
@@ -84,6 +88,29 @@ def render(self, ctx: RenderContext) -> list[Line]:
  return lines
 
 
+def _preserve_line_breaks(text: str) -> str:
+ """Turn single newlines into hard breaks so RichMarkdown keeps them.
+
+ Rich collapses a single ``\\n`` (markdown soft break) into a space, so
+ pasted multi-line user messages render as one long auto-wrapped line.
+ A CommonMark hard break is a line ending in two spaces — Rich renders
+ each such line separately. Blank lines (paragraph separators) and the
+ interior of fenced code blocks are left untouched: trailing whitespace
+ is significant inside code blocks.
+ """
+ out: list[str] = []
+ in_fence = False
+ for line in text.split("\n"):
+ if line.lstrip().startswith("```"):
+ in_fence = not in_fence
+ out.append(line)
+ elif in_fence or not line.strip():
+ out.append(line)
+ else:
+ out.append(line + " ")
+ return "\n".join(out)
+
+
 @dataclass
 class StreamingMarkdown(Widget):
  """Incremental markdown renderer for token-by-token streaming.

diff --git a/tests/test_composer.py b/tests/test_composer.py
@@ -0,0 +1,87 @@
+"""Tests for the Composer widget (multi-line input rendering).
+
+rant 2026-08-19T14:25:55: pasted multi-line text must render as one line
+per logical line — the first line carries the prompt, continuation lines a
+same-width indent, and the cursor is drawn on the line it currently sits
+in. (The old single-Line render was flattened by the buffer, which skips
+\\n characters → long auto-wrapped blob.)
+"""
+
+from __future__ import annotations
+
+from emrg.client.python_tui.widgets.base import RenderContext
+from emrg.client.python_tui.widgets.composer import Composer
+
+
+def _render_text(text: str, cursor: int | None = None) -> list[str]:
+ composer = Composer()
+ if text:
+ composer._text = text
+ composer._cursor = len(text) if cursor is None else cursor
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ return ["".join(s.text for s in line.spans) for line in lines]
+
+
+def test_composer_single_line():
+ """Single-line input keeps the prompt on the only line."""
+ out = _render_text("hello")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
+ assert "hello" in out[0]
+
+
+def test_composer_multiline_one_line_per_logical_line():
+ """Multi-line text renders one Line per logical line (rant 14:25:55)."""
+ out = _render_text("line1\nline2\nline3")
+ assert len(out) == 3
+ assert out[0].startswith("> ")
+ assert out[0][2:].strip().startswith("line1")
+ # Continuation lines: same-width indent, no prompt symbol
+ assert out[1].startswith(" ")
+ assert out[1].lstrip().startswith("line2")
+ assert out[2].startswith(" ")
+ assert out[2].lstrip().startswith("line3")
+
+
+def test_composer_multiline_no_prompt_on_continuation():
+ """Only the first line carries '> '; continuation uses indent only."""
+ out = _render_text("a\nb")
+ assert out[0].startswith("> ")
+ assert out[1].startswith(" ")
+ assert not out[1].lstrip().startswith(">")
+ assert out[1].strip() == "b"
+
+
+def test_composer_cursor_mid_first_line():
+ """Cursor in the middle of the first line is drawn there."""
+ composer = Composer()
+ composer._text = "abcd\nef"
+ composer._cursor = 2 # between 'ab' and 'cd'
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ first = "".join(s.text for s in lines[0].spans)
+ # prompt '> ' + prefix 'ab' + cursor 'c' + suffix 'd'
+ assert first == "> abcd"
+ assert lines[0].spans[2].text == "c" # the cursor span
+
+
+def test_composer_cursor_on_second_line():
+ """Cursor on a continuation line is drawn there, first line stays plain."""
+ composer = Composer()
+ composer._text = "ab\ncdef"
+ composer._cursor = 3 + 1 # 'a'=0,'b'=1,'\n'=2,'c'=3 → cursor at 'd' (idx 4? no)
+ # offsets: a0 b1 \n2 c3 d4 e5 f6 → cursor 4 = 'd'
+ composer._cursor = 4
+ ctx = RenderContext(width=80)
+ lines = composer.render(ctx)
+ second = "".join(s.text for s in lines[1].spans)
+ # prefix 'c' + cursor 'd' + suffix 'ef'
+ assert second.lstrip().startswith("cd")
+
+
+def test_composer_empty_placeholder():
+ """Empty composer renders a single dim prompt line."""
+ out = _render_text("")
+ assert len(out) == 1
+ assert out[0].startswith("> ")
diff --git a/tests/test_user_markdown.py b/tests/test_user_markdown.py
@@ -100,3 +100,42 @@ def test_chat_history_update_last_updates_user_markdown():
  chat.update_last("updated text")
  assert isinstance(chat.rows[0], UserMarkdown)
  assert chat.rows[0].text == "updated text"
+
+
+def test_user_markdown_preserves_single_newlines():
+ """Pasted multi-line text keeps its line breaks (rant 2026-08-19T14:25:55).
+
+ RichMarkdown would collapse single \\n into spaces; the hard-break
+ preprocessing must keep each logical line separate with "> " only on
+ the first line and a same-width indent on continuation lines.
+ """
+ visible = _render("line1\nline2\nline3", 40)
+ assert len(visible) == 3
+ assert visible[0].startswith("> ")
+ assert "line1" in visible[0]
+ assert visible[1].startswith(" ")
+ assert "line2" in visible[1]
+ assert visible[2].startswith(" ")
+ assert "line3" in visible[2]
+
+
+def test_user_markdown_preserves_blank_lines_as_paragraphs():
+ """Blank lines still act as paragraph separators (\\n\\n unchanged)."""
+ visible = _render("para one\n\npara two", 40)
+ # two paragraphs → at least 2 rendered lines, second starts fresh
+ assert len(visible) >= 2
+ assert "para one" in visible[0]
+ assert "para two" in visible[-1]
+
+
+def test_preserve_line_breaks_skips_fenced_code_blocks():
+ """Lines inside ``` fences are not given trailing hard-break spaces."""
+ from emrg.client.python_tui.widgets.markdown import _preserve_line_breaks
+
+ text = "intro\n```\ncode line 1\ncode line 2\n```\noutro"
+ out = _preserve_line_breaks(text)
+ parts = out.split("\n")
+ assert parts[0] == "intro " # plain line → hard break
+ assert parts[2] == "code line 1" # fence interior untouched
+ assert parts[3] == "code line 2"
+ assert parts[5] == "outro "