diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2496c1d5..54803dfd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,11 @@
   - `CitationInfo` and `QAResponse` models for structured responses
   - Natural language document filtering via `build_document_filter()`
   - Configurable search limit per agent
+- **Chat TUI** (`haiku-rag chat`): Terminal-based chat interface using Textual
+  - Single chat window with inline tool calls and expandable citations
+  - Visual grounding (`v` key) reuses inspector's `VisualGroundingModal`
+  - Database info (`i` key) shows document/chunk counts and storage info
+  - Keybindings: `q` quit, `Ctrl+L` clear chat, `Escape` focus input
 - **Q/A History Management**: Intelligent conversation history with semantic ranking
   - FIFO queue with 50 max entries
   - Embedding cache to avoid re-embedding Q/A pairs
diff --git a/haiku_rag_slim/haiku/rag/chat/__init__.py b/haiku_rag_slim/haiku/rag/chat/__init__.py
new file mode 100644
index 00000000..73fc5547
--- /dev/null
+++ b/haiku_rag_slim/haiku/rag/chat/__init__.py
@@ -0,0 +1,31 @@
+from datetime import datetime
+from pathlib import Path
+
+
+def run_chat(
+    db_path: Path | None = None,
+    read_only: bool = False,
+    before: datetime | None = None,
+) -> None:
+    """Run the chat TUI.
+
+    Args:
+        db_path: Path to the LanceDB database. If None, uses default from config.
+        read_only: Whether to open the database in read-only mode.
+        before: Query database as it existed before this datetime.
+    """
+    try:
+        from haiku.rag.chat.app import ChatApp
+    except ImportError as e:
+        raise ImportError(
+            "Textual is required for the chat TUI. Install with: pip install textual"
+        ) from e
+
+    from haiku.rag.config import get_config
+
+    config = get_config()
+    if db_path is None:
+        db_path = config.storage.data_dir / "haiku.rag.lancedb"
+
+    app = ChatApp(db_path, read_only=read_only, before=before)
+    app.run()
diff --git a/haiku_rag_slim/haiku/rag/chat/app.py b/haiku_rag_slim/haiku/rag/chat/app.py
new file mode 100644
index 00000000..7536ac96
--- /dev/null
+++ b/haiku_rag_slim/haiku/rag/chat/app.py
@@ -0,0 +1,324 @@
+# pyright: reportPossiblyUnboundVariable=false
+import asyncio
+import uuid
+from collections.abc import AsyncIterable
+from datetime import datetime
+from pathlib import Path
+from typing import TYPE_CHECKING, Any
+
+from ag_ui.core import EventType
+from pydantic_ai import (
+    Agent,
+    AgentStreamEvent,
+    FunctionToolCallEvent,
+    FunctionToolResultEvent,
+    RunContext,
+)
+from pydantic_ai.messages import ModelMessage
+
+from haiku.rag.agents.chat.agent import create_chat_agent
+from haiku.rag.agents.chat.state import ChatDeps, ChatSessionState, CitationInfo
+from haiku.rag.client import HaikuRAG
+from haiku.rag.config import get_config
+
+if TYPE_CHECKING:
+    from textual.app import ComposeResult
+
+try:
+    import logfire
+
+    logfire.configure(console=False)
+except ImportError:
+    pass
+
+try:
+    import textual_image.widget  # noqa: F401 - import early for renderer detection
+    from textual.app import App
+    from textual.binding import Binding
+    from textual.widgets import Footer, Header, Input
+    from textual.worker import Worker
+
+    from haiku.rag.chat.widgets.chat_history import ChatHistory, CitationWidget
+
+    TEXTUAL_AVAILABLE = True
+except ImportError:
+    TEXTUAL_AVAILABLE = False
+    App = object  # type: ignore
+
+
+class ChatApp(App):  # type: ignore[misc]
+    """Textual TUI for conversational RAG."""
+
+    TITLE = "haiku.rag Chat"
+
+    CSS = """
+    Screen {
+        layout: grid;
+        grid-size: 1 2;
+        grid-rows: 1fr auto;
+        background: $surface;
+    }
+
+    #chat-history {
+        height: 100%;
+    }
+
+    Header {
+        background: $primary;
+    }
+
+    Footer {
+        background: $surface-darken-1;
+    }
+    """
+
+    BINDINGS = [
+        Binding("ctrl+l", "clear_chat", "Clear", show=True),
+        Binding("ctrl+g", "show_visual", "Visual", show=True),
+        Binding("ctrl+i", "show_info", "Info", show=True),
+        Binding("escape", "focus_input", "Focus Input", show=False),
+    ]
+
+    def __init__(
+        self, db_path: Path, read_only: bool = False, before: datetime | None = None
+    ) -> None:
+        super().__init__()
+        self.db_path = db_path
+        self.read_only = read_only
+        self.before = before
+        self.client: HaikuRAG | None = None
+        self.config = get_config()
+        self.agent: Agent[ChatDeps, str] | None = None
+        self.session_state: ChatSessionState | None = None
+        self._is_processing = False
+        self._tool_call_widgets: dict[str, Any] = {}
+        self._last_citations: list[CitationInfo] = []
+        self._selected_citation_idx: int | None = None
+        self._current_worker: Worker[None] | None = None
+        self._message_history: list[ModelMessage] = []
+
+    def compose(self) -> "ComposeResult":
+        """Compose the UI layout."""
+        yield Header()
+        yield ChatHistory(id="chat-history")
+        yield Input(placeholder="Ask a question...", id="chat-input")
+        yield Footer()
+
+    async def on_mount(self) -> None:
+        """Initialize the app when mounted."""
+        self.client = HaikuRAG(
+            db_path=self.db_path,
+            config=self.config,
+            read_only=self.read_only,
+            before=self.before,
+        )
+        await self.client.__aenter__()
+
+        # Create agent and session state
+        self.agent = create_chat_agent(self.config)
+        self.session_state = ChatSessionState(session_id=str(uuid.uuid4()))
+
+        # Focus the input field
+        self.query_one(Input).focus()
+
+    async def on_unmount(self) -> None:
+        """Clean up when unmounting."""
+        if self.client:
+            await self.client.__aexit__(None, None, None)
+
+    async def _handle_stream_event(self, event: AgentStreamEvent) -> None:
+        """Handle streaming events from the agent."""
+        chat_history = self.query_one(ChatHistory)
+
+        if isinstance(event, FunctionToolCallEvent):
+            tool_name = event.part.tool_name
+            tool_call_id = event.part.tool_call_id or str(uuid.uuid4())
+            args = event.part.args_as_dict()
+            widget = await chat_history.add_tool_call(tool_name, args)
+            self._tool_call_widgets[tool_call_id] = widget
+
+        elif isinstance(event, FunctionToolResultEvent):
+            tool_call_id = event.tool_call_id
+            if tool_call_id and tool_call_id in self._tool_call_widgets:
+                widget = self._tool_call_widgets[tool_call_id]
+                chat_history.mark_tool_complete(widget)
+
+            # Extract citations from StateSnapshotEvent in tool metadata
+            result = getattr(event, "result", None)
+            metadata = getattr(result, "metadata", None) if result else None
+            if metadata:
+                for meta_event in metadata:
+                    if (
+                        hasattr(meta_event, "type")
+                        and meta_event.type == EventType.STATE_SNAPSHOT
+                    ):
+                        snapshot = getattr(meta_event, "snapshot", {})
+                        if "citations" in snapshot:
+                            self._last_citations = [
+                                CitationInfo(**c) for c in snapshot["citations"]
+                            ]
+
+    async def _event_stream_handler(
+        self,
+        _ctx: RunContext[ChatDeps],
+        event_stream: AsyncIterable[AgentStreamEvent],
+    ) -> None:
+        """Handle streaming events from the agent."""
+        async for event in event_stream:
+            await self._handle_stream_event(event)
+            # Yield to event loop to keep UI responsive
+            await asyncio.sleep(0)
+
+    async def on_input_submitted(self, event: Input.Submitted) -> None:
+        """Handle user input submission."""
+        user_message = event.value.strip()
+        if not user_message or self._is_processing:
+            return
+
+        if not self.client or not self.agent:
+            return
+
+        # Clear the input
+        event.input.clear()
+
+        # Add user message to history
+        chat_history = self.query_one(ChatHistory)
+        await chat_history.add_message("user", user_message)
+
+        # Clear for new query
+        self._tool_call_widgets.clear()
+        self._last_citations.clear()
+        self._selected_citation_idx = None
+
+        # Run agent in a worker to keep UI responsive
+        self._is_processing = True
+        self.query_one(Input).disabled = True
+        self._current_worker = self.run_worker(
+            self._run_agent(user_message), exclusive=True
+        )
+
+    async def _run_agent(self, user_message: str) -> None:
+        """Run the agent in a background worker."""
+        if not self.client or not self.agent:
+            return
+
+        chat_history = self.query_one(ChatHistory)
+
+        # Show thinking indicator
+        await chat_history.show_thinking()
+
+        try:
+            deps = ChatDeps(
+                client=self.client,
+                config=self.config,
+                session_state=self.session_state,
+            )
+
+            async with self.agent.run_stream(
+                user_message,
+                deps=deps,
+                message_history=self._message_history,
+                event_stream_handler=self._event_stream_handler,
+            ) as stream:
+                # Hide thinking when we start getting content
+                chat_history.hide_thinking()
+
+                # Create assistant message for streaming
+                assistant_msg = await chat_history.add_message("assistant", "")
+
+                # Stream text updates
+                async for text in stream.stream_text():
+                    assistant_msg.update_content(text)
+                    chat_history.scroll_end(animate=False)
+                    # Yield to event loop to keep UI responsive
+                    await asyncio.sleep(0)
+
+                # Update message history with this conversation
+                self._message_history = stream.all_messages()
+
+                # Add citations captured from tool metadata
+                if self._last_citations:
+                    await chat_history.add_citations(self._last_citations)
+
+        except asyncio.CancelledError:
+            chat_history.hide_thinking()
+            await chat_history.add_message("assistant", "*Cancelled*")
+        except Exception as e:
+            chat_history.hide_thinking()
+            await chat_history.add_message("assistant", f"Error: {e}")
+        finally:
+            self._is_processing = False
+            self._current_worker = None
+            chat_input = self.query_one(Input)
+            chat_input.disabled = False
+            chat_input.focus()
+
+    async def action_clear_chat(self) -> None:
+        """Clear the chat history and reset session."""
+        chat_history = self.query_one(ChatHistory)
+        await chat_history.clear_messages()
+        self._last_citations.clear()
+        self._selected_citation_idx = None
+        self._message_history.clear()
+        # Reset session state for fresh conversation
+        self.session_state = ChatSessionState(session_id=str(uuid.uuid4()))
+
+    def action_focus_input(self) -> None:
+        """Focus the input field, or cancel if processing."""
+        if self._is_processing and self._current_worker:
+            self._current_worker.cancel()
+        self.query_one(Input).focus()
+
+    def _clear_citation_selection(self) -> None:
+        """Clear citation selection."""
+        chat_history = self.query_one(ChatHistory)
+        for widget in chat_history.query(CitationWidget):
+            widget.remove_class("selected")
+        self._selected_citation_idx = None
+
+    def on_descendant_focus(self, _event: object) -> None:
+        """Clear citation selection when input is focused."""
+        if isinstance(self.focused, Input):
+            self._clear_citation_selection()
+
+    async def action_show_visual(self) -> None:
+        """Show visual grounding for the selected citation."""
+        if not self.client or not self._last_citations:
+            return
+
+        idx = (
+            self._selected_citation_idx
+            if self._selected_citation_idx is not None
+            else 0
+        )
+        citation = self._last_citations[idx]
+        chunk = await self.client.chunk_repository.get_by_id(citation.chunk_id)
+        if not chunk:
+            return
+
+        from haiku.rag.inspector.widgets.visual_modal import VisualGroundingModal
+
+        await self.push_screen(VisualGroundingModal(chunk=chunk, client=self.client))
+
+    async def action_show_info(self) -> None:
+        """Show database info modal."""
+        if not self.client:
+            return
+
+        from haiku.rag.inspector.widgets.info_modal import InfoModal
+
+        await self.push_screen(InfoModal(self.client, self.db_path))
+
+    def on_citation_widget_selected(self, event: CitationWidget.Selected) -> None:
+        """Handle citation selection."""
+        chat_history = self.query_one(ChatHistory)
+
+        # Remove selected class from all citations
+        for widget in chat_history.query(CitationWidget):
+            widget.remove_class("selected")
+
+        # Add selected class to the newly selected citation
+        citation_widgets = list(chat_history.query(CitationWidget))
+        if 0 <= event.citation_index < len(citation_widgets):
+            citation_widgets[event.citation_index].add_class("selected")
+            self._selected_citation_idx = event.citation_index
diff --git a/haiku_rag_slim/haiku/rag/chat/widgets/__init__.py b/haiku_rag_slim/haiku/rag/chat/widgets/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/haiku_rag_slim/haiku/rag/chat/widgets/chat_history.py b/haiku_rag_slim/haiku/rag/chat/widgets/chat_history.py
new file mode 100644
index 00000000..d6b4b0c9
--- /dev/null
+++ b/haiku_rag_slim/haiku/rag/chat/widgets/chat_history.py
@@ -0,0 +1,354 @@
+from typing import TYPE_CHECKING
+
+from textual.containers import Horizontal, VerticalScroll
+from textual.message import Message
+from textual.widgets import Collapsible, LoadingIndicator, Markdown, Static
+
+from haiku.rag.agents.chat.state import CitationInfo
+
+if TYPE_CHECKING:
+    from textual.app import ComposeResult
+    from textual.events import Key
+
+
+class ChatMessage(Static):
+    """A single chat message with role styling."""
+
+    def __init__(self, role: str, content: str = "", **kwargs) -> None:
+        super().__init__(**kwargs)
+        self.role = role
+        self.content = content
+
+    def compose(self) -> "ComposeResult":
+        prefix = "**You:**" if self.role == "user" else "**Assistant:**"
+        yield Markdown(f"{prefix}\n\n{self.content}", id="message-content")
+
+    def update_content(self, content: str) -> None:
+        """Update the message content (for streaming)."""
+        self.content = content
+        prefix = "**You:**" if self.role == "user" else "**Assistant:**"
+        markdown = self.query_one("#message-content", Markdown)
+        markdown.update(f"{prefix}\n\n{content}")
+
+
+class ToolCallWidget(Static):
+    """Styled inline display of a tool call."""
+
+    TOOL_LABELS = {
+        "search": "Searching",
+        "ask": "Asking",
+        "get_document": "Fetching",
+    }
+
+    def __init__(self, tool_name: str, args: dict | None = None, **kwargs) -> None:
+        super().__init__(**kwargs)
+        self.tool_name = tool_name
+        self.args = args or {}
+        self._complete = False
+
+    def compose(self) -> "ComposeResult":
+        label = self.TOOL_LABELS.get(self.tool_name, self.tool_name)
+
+        # Build description based on tool type
+        if self.tool_name == "search":
+            query = self.args.get("query", "...")
+            doc = self.args.get("document_name")
+            desc = f'"{query}"'
+            if doc:
+                desc += f" in {doc}"
+        elif self.tool_name == "ask":
+            question = self.args.get("question", "...")
+            doc = self.args.get("document_name")
+            desc = f'"{question}"'
+            if doc:
+                desc += f" from {doc}"
+        elif self.tool_name == "get_document":
+            query = self.args.get("query", "...")
+            desc = f'"{query}"'
+        else:
+            desc = str(self.args) if self.args else ""
+
+        with Horizontal(classes="tool-row"):
+            if self._complete:
+                yield Static("✓", classes="tool-status")
+            else:
+                yield LoadingIndicator(classes="tool-spinner")
+            yield Static(label, classes="tool-badge")
+            yield Static(desc, classes="tool-desc")
+
+    def mark_complete(self) -> None:
+        self._complete = True
+        self.refresh(recompose=True)
+
+
+class CitationWidget(Collapsible):
+    """Inline expandable citation."""
+
+    can_focus = True
+    can_focus_children = False
+
+    class Selected(Message):
+        """Message sent when a citation is selected."""
+
+        def __init__(self, citation_index: int) -> None:
+            super().__init__()
+            self.citation_index = citation_index
+
+    def __init__(self, citation: CitationInfo, **kwargs) -> None:
+        title = f"[{citation.index}] {citation.document_title or citation.document_uri}"
+        if citation.page_numbers:
+            pages = ", ".join(map(str, citation.page_numbers[:3]))
+            if len(citation.page_numbers) > 3:
+                pages += "..."
+            title += f" (p.{pages})"
+
+        # Build content widgets
+        content = citation.content
+        if len(content) > 500:
+            content = content[:500] + "..."
+
+        children: list[Markdown | Static] = [Markdown(content)]
+        if citation.headings:
+            headings = " > ".join(citation.headings[:3])
+            children.append(Static(f"Section: {headings}", classes="citation-metadata"))
+        children.append(
+            Static(f"Source: {citation.document_uri}", classes="citation-metadata")
+        )
+
+        super().__init__(*children, title=title, collapsed=True, **kwargs)
+        self.citation = citation
+
+    def on_focus(self) -> None:
+        """When focused, mark as selected."""
+        self.post_message(self.Selected(self.citation.index - 1))
+
+    def on_key(self, event: "Key") -> None:
+        """Handle Enter to toggle expand/collapse."""
+        if event.key == "enter":
+            self.collapsed = not self.collapsed
+            event.stop()
+
+
+class ThinkingWidget(Static):
+    """Thinking indicator shown while agent is processing."""
+
+    def compose(self) -> "ComposeResult":
+        with Horizontal(classes="thinking-row"):
+            yield LoadingIndicator(classes="thinking-spinner")
+            yield Static("Thinking...", classes="thinking-text")
+
+
+class SourcesHeader(Static):
+    """Header for the citations section."""
+
+    def __init__(self, count: int, **kwargs) -> None:
+        super().__init__(f"Sources ({count})", **kwargs)
+
+
+class ChatHistory(VerticalScroll):
+    """Scrollable container for chat messages, tool calls, and citations."""
+
+    can_focus = True
+
+    DEFAULT_CSS = """
+    ChatHistory {
+        height: 100%;
+        background: $surface;
+        padding: 1 2;
+    }
+
+    /* Messages */
+    ChatMessage {
+        margin: 1 0;
+        padding: 1 2;
+        background: $panel;
+    }
+
+    ChatMessage.user {
+        background: $primary 15%;
+        border-left: thick $primary;
+        margin-right: 4;
+    }
+
+    ChatMessage.assistant {
+        background: $success 15%;
+        border-left: thick $success;
+        margin-left: 4;
+    }
+
+    ChatMessage Markdown {
+        margin: 0;
+        padding: 0;
+    }
+
+    /* Tool calls */
+    ToolCallWidget {
+        margin: 0 0 0 4;
+        padding: 0 1;
+        height: auto;
+        background: $surface;
+        border-left: thick $warning;
+    }
+
+    ToolCallWidget.complete {
+        border-left: thick $success;
+    }
+
+    .tool-row {
+        height: auto;
+        width: 100%;
+    }
+
+    .tool-spinner {
+        width: 2;
+        height: 1;
+        color: $warning;
+    }
+
+    .tool-status {
+        width: 2;
+        color: $success;
+    }
+
+    .tool-badge {
+        width: auto;
+        color: $text;
+        text-style: bold;
+        padding-right: 1;
+    }
+
+    .tool-desc {
+        width: 1fr;
+        color: $text-muted;
+    }
+
+    /* Sources section */
+    SourcesHeader {
+        margin: 2 0 1 0;
+        padding: 0 1;
+        text-style: bold;
+        color: $text;
+        background: $primary 15%;
+        border-left: thick $primary;
+    }
+
+    /* Citations */
+    CitationWidget {
+        margin: 0 0 0 2;
+        background: $surface;
+    }
+
+    CitationWidget > CollapsibleTitle {
+        padding: 0 1;
+        color: $text-muted;
+    }
+
+    CitationWidget:focus {
+        background: $accent 15%;
+        border-left: thick $accent;
+    }
+
+    CitationWidget:focus > CollapsibleTitle {
+        color: $text;
+        text-style: bold;
+    }
+
+    CitationWidget.selected {
+        background: $accent 15%;
+        border-left: thick $accent;
+    }
+
+    CitationWidget.selected > CollapsibleTitle {
+        color: $text;
+        text-style: bold;
+    }
+
+    CitationWidget Contents {
+        padding: 1 2;
+        background: $panel;
+    }
+
+    CitationWidget .citation-metadata {
+        margin-top: 1;
+        color: $text-muted;
+        text-style: italic;
+    }
+
+    /* Thinking indicator */
+    ThinkingWidget {
+        margin: 1 0 0 4;
+        padding: 0 1;
+        height: auto;
+        background: $surface;
+        border-left: thick $primary;
+    }
+
+    .thinking-row {
+        height: auto;
+        width: 100%;
+    }
+
+    .thinking-spinner {
+        width: 2;
+        height: 1;
+        color: $primary;
+    }
+
+    .thinking-text {
+        color: $text-muted;
+        text-style: italic;
+    }
+    """
+
+    def __init__(self, **kwargs) -> None:
+        super().__init__(**kwargs)
+        self.messages: list[tuple[str, str]] = []
+
+    async def add_message(self, role: str, content: str = "") -> ChatMessage:
+        """Add a message to the chat history."""
+        self.messages.append((role, content))
+        message_widget = ChatMessage(role, content, classes=role)
+        await self.mount(message_widget)
+        self.scroll_end(animate=False)
+        return message_widget
+
+    async def add_tool_call(
+        self, tool_name: str, args: dict | None = None
+    ) -> ToolCallWidget:
+        """Add an inline tool call indicator."""
+        widget = ToolCallWidget(tool_name, args)
+        await self.mount(widget)
+        self.scroll_end(animate=False)
+        return widget
+
+    def mark_tool_complete(self, widget: ToolCallWidget) -> None:
+        """Mark a tool call as complete."""
+        widget.mark_complete()
+        widget.add_class("complete")
+
+    async def add_citations(self, citations: list[CitationInfo]) -> None:
+        """Add citations inline after a response."""
+        if not citations:
+            return
+        await self.mount(SourcesHeader(len(citations)))
+        for citation in citations:
+            widget = CitationWidget(citation)
+            await self.mount(widget)
+        self.scroll_end(animate=False)
+
+    async def show_thinking(self) -> None:
+        """Show the thinking indicator."""
+        await self.mount(ThinkingWidget(id="thinking"))
+        self.scroll_end(animate=False)
+
+    def hide_thinking(self) -> None:
+        """Hide the thinking indicator."""
+        try:
+            self.query_one("#thinking", ThinkingWidget).remove()
+        except Exception:
+            pass
+
+    async def clear_messages(self) -> None:
+        """Clear all messages from the chat history."""
+        self.messages.clear()
+        await self.remove_children()
diff --git a/haiku_rag_slim/haiku/rag/cli.py b/haiku_rag_slim/haiku/rag/cli.py
index 9958cc07..11649c17 100644
--- a/haiku_rag_slim/haiku/rag/cli.py
+++ b/haiku_rag_slim/haiku/rag/cli.py
@@ -540,6 +540,21 @@ def inspect(
     run_inspector(db_path, read_only=_read_only, before=_before)
 
 
+@cli.command("chat", help="Launch interactive chat TUI for conversational RAG")
+def chat(
+    db: Path | None = typer.Option(
+        None,
+        "--db",
+        help="Path to the LanceDB database file",
+    ),
+):
+    """Launch the chat TUI for conversational RAG."""
+    from haiku.rag.chat import run_chat
+
+    db_path = db if db else get_config().storage.data_dir / "haiku.rag.lancedb"
+    run_chat(db_path, read_only=_read_only, before=_before)
+
+
 @cli.command(
     "serve",
     help="Start haiku.rag server. Use --monitor and/or --mcp to enable services.",
diff --git a/tests/chat/__init__.py b/tests/chat/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/chat/test_chat_app.py b/tests/chat/test_chat_app.py
new file mode 100644
index 00000000..66e7f7e4
--- /dev/null
+++ b/tests/chat/test_chat_app.py
@@ -0,0 +1,330 @@
+from pathlib import Path
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+from typer.testing import CliRunner
+
+from haiku.rag.cli import cli
+
+runner = CliRunner()
+
+
+def test_chat_command():
+    """Test chat command launches chat TUI."""
+    with patch("haiku.rag.chat.run_chat") as mock_chat:
+        mock_chat.return_value = None
+
+        result = runner.invoke(cli, ["chat"])
+
+        assert result.exit_code == 0
+        mock_chat.assert_called_once()
+
+
+@pytest.mark.asyncio
+async def test_chat_app_has_required_widgets(temp_db_path: Path):
+    """Test that ChatApp has the required widgets: ChatHistory, Input."""
+    from haiku.rag.chat.app import ChatApp
+    from haiku.rag.chat.widgets.chat_history import ChatHistory
+
+    mock_client = AsyncMock()
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=None)
+
+    with patch("haiku.rag.chat.app.HaikuRAG", return_value=mock_client):
+        app = ChatApp(temp_db_path, read_only=True)
+
+        async with app.run_test():
+            chat_history = app.query_one(ChatHistory)
+            assert chat_history is not None
+
+            from textual.widgets import Input
+
+            chat_input = app.query_one(Input)
+            assert chat_input is not None
+
+
+@pytest.mark.asyncio
+async def test_chat_app_quit_binding(temp_db_path: Path):
+    """Test that pressing ctrl+q quits the app."""
+    from haiku.rag.chat.app import ChatApp
+
+    mock_client = AsyncMock()
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=None)
+
+    with patch("haiku.rag.chat.app.HaikuRAG", return_value=mock_client):
+        app = ChatApp(temp_db_path, read_only=True)
+
+        async with app.run_test() as pilot:
+            # App should be running
+            assert app.is_running
+
+            # Press ctrl+q to quit
+            await pilot.press("ctrl+q")
+
+            # App should have exited
+            assert not app.is_running
+
+
+@pytest.mark.asyncio
+async def test_chat_history_can_add_message(temp_db_path: Path):
+    """Test that ChatHistory can display messages."""
+    from haiku.rag.chat.app import ChatApp
+    from haiku.rag.chat.widgets.chat_history import ChatHistory
+
+    mock_client = AsyncMock()
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=None)
+
+    with patch("haiku.rag.chat.app.HaikuRAG", return_value=mock_client):
+        app = ChatApp(temp_db_path, read_only=True)
+
+        async with app.run_test():
+            chat_history = app.query_one(ChatHistory)
+
+            # Add a user message
+            await chat_history.add_message("user", "Hello, how are you?")
+            assert len(chat_history.messages) == 1
+            assert chat_history.messages[0] == ("user", "Hello, how are you?")
+
+            # Add an assistant message
+            await chat_history.add_message("assistant", "I'm doing well, thank you!")
+            assert len(chat_history.messages) == 2
+
+
+@pytest.mark.asyncio
+async def test_chat_app_calls_agent_on_submit(temp_db_path: Path):
+    """Test that submitting a message triggers agent invocation."""
+    from contextlib import asynccontextmanager
+
+    from haiku.rag.chat.app import ChatApp
+    from haiku.rag.chat.widgets.chat_history import ChatHistory
+
+    mock_client = AsyncMock()
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=None)
+
+    # Create a mock stream result
+    mock_result = MagicMock()
+    mock_result.output = "This is the agent's response."
+
+    # Mock stream that returns the result
+    mock_stream = MagicMock()
+    mock_stream.get_result = AsyncMock(return_value=mock_result)
+
+    async def mock_stream_text():
+        yield "This is the agent's response."
+
+    mock_stream.stream_text = mock_stream_text
+
+    @asynccontextmanager
+    async def mock_run_stream(*args, **kwargs):
+        yield mock_stream
+
+    # Create a mock agent that returns a fixed response
+    mock_agent = MagicMock()
+    mock_agent.run_stream = mock_run_stream
+
+    with (
+        patch("haiku.rag.chat.app.HaikuRAG", return_value=mock_client),
+        patch("haiku.rag.chat.app.create_chat_agent", return_value=mock_agent),
+    ):
+        app = ChatApp(temp_db_path, read_only=True)
+
+        async with app.run_test() as pilot:
+            # Type a message in the input
+            await pilot.press("H", "e", "l", "l", "o")
+            await pilot.press("enter")
+
+            # Give the app time to process
+            await pilot.pause()
+
+            # Verify the response was added to chat history
+            chat_history = app.query_one(ChatHistory)
+            assert len(chat_history.messages) >= 2  # User message + agent response
+
+
+@pytest.mark.asyncio
+async def test_chat_history_can_add_tool_calls(temp_db_path: Path):
+    """Test that ChatHistory can display inline tool calls."""
+    from haiku.rag.chat.app import ChatApp
+    from haiku.rag.chat.widgets.chat_history import ChatHistory, ToolCallWidget
+
+    mock_client = AsyncMock()
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=None)
+
+    with patch("haiku.rag.chat.app.HaikuRAG", return_value=mock_client):
+        app = ChatApp(temp_db_path, read_only=True)
+
+        async with app.run_test():
+            chat_history = app.query_one(ChatHistory)
+
+            # Add a tool call
+            tool_widget = await chat_history.add_tool_call("search", {"query": "test"})
+            assert isinstance(tool_widget, ToolCallWidget)
+            assert tool_widget._complete is False
+
+            # Mark it complete
+            chat_history.mark_tool_complete(tool_widget)
+            assert tool_widget._complete is True
+
+
+@pytest.mark.asyncio
+async def test_chat_history_can_add_citations(temp_db_path: Path):
+    """Test that ChatHistory can display inline citations."""
+    from haiku.rag.agents.chat.state import CitationInfo
+    from haiku.rag.chat.app import ChatApp
+    from haiku.rag.chat.widgets.chat_history import ChatHistory, CitationWidget
+
+    mock_client = AsyncMock()
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=None)
+
+    with patch("haiku.rag.chat.app.HaikuRAG", return_value=mock_client):
+        app = ChatApp(temp_db_path, read_only=True)
+
+        async with app.run_test():
+            chat_history = app.query_one(ChatHistory)
+
+            test_citations = [
+                CitationInfo(
+                    index=1,
+                    document_id="doc1",
+                    chunk_id="chunk1",
+                    document_uri="file:///test/doc1.pdf",
+                    document_title="Test Document 1",
+                    page_numbers=[1, 2],
+                    headings=["Section 1"],
+                    content="This is some test content from doc 1",
+                ),
+                CitationInfo(
+                    index=2,
+                    document_id="doc2",
+                    chunk_id="chunk2",
+                    document_uri="file:///test/doc2.pdf",
+                    document_title="Test Document 2",
+                    page_numbers=[5],
+                    headings=["Section 2", "Subsection"],
+                    content="This is test content from doc 2",
+                ),
+            ]
+
+            await chat_history.add_citations(test_citations)
+
+            # Verify citation widgets were added
+            citation_widgets = chat_history.query(CitationWidget)
+            assert len(list(citation_widgets)) == 2
+
+
+@pytest.mark.asyncio
+async def test_chat_history_thinking_indicator(temp_db_path: Path):
+    """Test that ChatHistory can show and hide thinking indicator."""
+    from haiku.rag.chat.app import ChatApp
+    from haiku.rag.chat.widgets.chat_history import ChatHistory, ThinkingWidget
+
+    mock_client = AsyncMock()
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=None)
+
+    with patch("haiku.rag.chat.app.HaikuRAG", return_value=mock_client):
+        app = ChatApp(temp_db_path, read_only=True)
+
+        async with app.run_test() as pilot:
+            chat_history = app.query_one(ChatHistory)
+
+            # Show thinking indicator
+            await chat_history.show_thinking()
+            thinking = chat_history.query(ThinkingWidget)
+            assert len(list(thinking)) == 1
+
+            # Hide thinking indicator (remove is deferred, so pause)
+            chat_history.hide_thinking()
+            await pilot.pause()
+            thinking = chat_history.query(ThinkingWidget)
+            assert len(list(thinking)) == 0
+
+
+@pytest.mark.asyncio
+async def test_clear_chat_resets_session(temp_db_path: Path):
+    """Test that clearing chat resets the session state."""
+    from haiku.rag.chat.app import ChatApp
+    from haiku.rag.chat.widgets.chat_history import ChatHistory
+
+    mock_client = AsyncMock()
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=None)
+
+    with patch("haiku.rag.chat.app.HaikuRAG", return_value=mock_client):
+        app = ChatApp(temp_db_path, read_only=True)
+
+        async with app.run_test() as pilot:
+            chat_history = app.query_one(ChatHistory)
+
+            # Add some messages
+            await chat_history.add_message("user", "Hello")
+            await chat_history.add_message("assistant", "Hi there")
+            assert len(chat_history.messages) == 2
+
+            # Store original session ID
+            assert app.session_state is not None
+            original_session_id = app.session_state.session_id
+
+            # Clear chat
+            await pilot.press("ctrl+l")
+            await pilot.pause()
+
+            # Verify messages cleared
+            assert len(chat_history.messages) == 0
+
+            # Verify session state reset (new session ID)
+            assert app.session_state is not None
+            assert app.session_state.session_id != original_session_id
+
+
+@pytest.mark.asyncio
+async def test_citation_expand_collapse_with_enter(temp_db_path: Path):
+    """Test that pressing Enter on a focused citation toggles expand/collapse."""
+    from haiku.rag.agents.chat.state import CitationInfo
+    from haiku.rag.chat.app import ChatApp
+    from haiku.rag.chat.widgets.chat_history import ChatHistory, CitationWidget
+
+    mock_client = AsyncMock()
+    mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+    mock_client.__aexit__ = AsyncMock(return_value=None)
+
+    with patch("haiku.rag.chat.app.HaikuRAG", return_value=mock_client):
+        app = ChatApp(temp_db_path, read_only=True)
+
+        async with app.run_test() as pilot:
+            chat_history = app.query_one(ChatHistory)
+
+            # Add a citation
+            test_citation = CitationInfo(
+                index=1,
+                document_id="doc1",
+                chunk_id="chunk1",
+                document_uri="file:///test/doc1.pdf",
+                document_title="Test Document",
+                page_numbers=[1],
+                content="Test content",
+            )
+            await chat_history.add_citations([test_citation])
+
+            # Get the citation widget
+            citation_widget = chat_history.query_one(CitationWidget)
+            assert citation_widget.collapsed is True
+
+            # Focus the citation
+            citation_widget.focus()
+            await pilot.pause()
+
+            # Press Enter to expand
+            await pilot.press("enter")
+            await pilot.pause()
+            assert citation_widget.collapsed is False
+
+            # Press Enter again to collapse
+            await pilot.press("enter")
+            await pilot.pause()
+            assert citation_widget.collapsed is True