diff --git a/clients/terminal/tui/renderers/message.py b/clients/terminal/tui/renderers/message.py
index 6cfb4b2..75871b1 100644
--- a/clients/terminal/tui/renderers/message.py
+++ b/clients/terminal/tui/renderers/message.py
@@ -4,12 +4,14 @@
 
 from rich.console import RenderableType
 from rich.box import ROUNDED
+from rich.markdown import Markdown
 from rich.panel import Panel
 from rich.text import Text
 
 from clients.terminal.tui.themes import get_active_theme
 
 from .base import ContentRenderer
+from .markdown_content import ThemedMarkdownRenderable, _theme_aware_code_theme
 
 
 def _hex_style(color) -> str:
@@ -36,16 +38,27 @@
 
 
 class AssistantMessageRenderer(ContentRenderer):
-    """Render a completed assistant response as a panel."""
+    """Render an assistant response as a panel with markdown content.
+
+    The body is parsed as markdown (headings, lists, bold/italic, inline and
+    fenced code blocks with theme-aware syntax highlighting) using the same
+    themed renderer as the planning cards. Re-rendered on every stream delta
+    so the formatting appears live as Navi streams.
+    """
 
     def accepts(self, msg: dict) -> bool:
         return msg.get("type") == "assistant_message"
 
     def render(self, msg: dict) -> RenderableType:
         theme = get_active_theme()
-        text = msg.get("content", "")
+        text = msg.get("content", "") or ""
+        code_theme = _theme_aware_code_theme(theme.name)
+        body = ThemedMarkdownRenderable(
+            Markdown(text, code_theme=code_theme, inline_code_theme=code_theme),
+            theme.name,
+        )
         return Panel(
-            Text(text, style=_hex_style(theme.text)),
+            body,
             title="Navi",
             title_align="left",
             border_style=_hex_style(theme.assistant_bubble),
diff --git a/tests/clients/test_message_renderers.py b/tests/clients/test_message_renderers.py
new file mode 100644
index 0000000..12ffbf2
--- /dev/null
+++ b/tests/clients/test_message_renderers.py
@@ -0,0 +1,67 @@
+"""Tests for user/assistant message renderers (markdown in Navi's answers)."""
+
+from __future__ import annotations
+
+from rich.console import Console
+
+from clients.terminal.tui.renderers.message import (
+    AssistantMessageRenderer,
+    UserMessageRenderer,
+)
+from clients.terminal.tui.themes import set_active_theme
+
+
+def _render_text(renderable) -> str:
+    console = Console(record=True, width=80, force_terminal=True, color_system=None)
+    console.print(renderable)
+    return console.export_text()
+
+
+def test_assistant_message_renders_markdown_headings_and_code() -> None:
+    """Navi's answer is parsed as markdown, not shown as raw syntax."""
+    set_active_theme("gnexus-dark")
+    renderer = AssistantMessageRenderer()
+    msg = {
+        "type": "assistant_message",
+        "content": "## Result\n\nThe value is `42`.\n\n```python\nx = 1\n```",
+    }
+    out = _render_text(renderer.render(msg))
+    # Heading renders (not as a literal "## Result" line).
+    assert "Result" in out
+    assert "##" not in out
+    # Inline code content present, fenced code present.
+    assert "42" in out
+    assert "x = 1" in out
+    # Backticks are consumed by the markdown renderer, not echoed literally.
+    assert "```" not in out
+
+
+def test_assistant_message_panel_titled_navi() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = AssistantMessageRenderer()
+    panel = renderer.render({"type": "assistant_message", "content": "hi"})
+    assert str(panel.title) == "Navi"
+
+
+def test_assistant_message_empty_content_renders_without_error() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = AssistantMessageRenderer()
+    out = _render_text(renderer.render({"type": "assistant_message", "content": ""}))
+    assert "Navi" in out
+
+
+def test_assistant_renderer_does_not_accept_user_message() -> None:
+    assert not AssistantMessageRenderer().accepts({"type": "user_message", "content": "x"})
+
+
+def test_user_message_stays_plain_text() -> None:
+    """User messages are NOT markdown-rendered — syntax shows literally."""
+    set_active_theme("gnexus-dark")
+    renderer = UserMessageRenderer()
+    out = _render_text(
+        renderer.render({"type": "user_message", "content": "## not a heading\n**bold**"})
+    )
+    # Raw markdown syntax is preserved for user input.
+    assert "## not a heading" in out
+    assert "**bold**" in out
+    assert str(renderer.render({"type": "user_message", "content": "x"}).title) == "You"
\ No newline at end of file