Merge pull request #363 from ggozad/feat/chat-tui-markdown-streaming

Support streaming for markdown

CHANGELOG.md

@@ -9,6 +9,10 @@
 - **`[s3]` optional extra** (`obstore>=0.9`). Required for `s3://` sources and the S3 watcher. Uses obstore — the Python binding to the same Rust `object_store` crate that LanceDB uses internally — so `monitor.s3[*].storage_options` accepts the same dict shape as `lancedb.storage_options`. Empty/missing options fall back to the AWS default credential chain.
 - **`scripts/run-integration-tests.sh`** — wraps `docker compose up --wait`, `pytest -m integration`, and tear-down so the SeaweedFS-backed integration suite is a one-liner.
 
+### Changed
+
+- **Chat TUI streams markdown incrementally.** Assistant messages now use Textual's `MarkdownStream` (`Markdown.get_stream`) and write per-token deltas instead of re-parsing the entire accumulated message on every token. Removes the O(n²) re-parse that visibly stuttered long responses. Bumps `textual` floor to `>=8.2.4` so `Markdown.get_stream` is reachable via the public API.
+
 ### Fixed
 
 - **Conversion options now apply to non-PDF formats.** `DoclingLocalConverter` previously wired its `PdfPipelineOptions` only to `InputFormat.PDF`, so user settings (OCR knobs, `picture_description.enabled`, `images_scale`, etc.) silently no-op'd for HTML, Markdown, DOCX, PPTX, and IMAGE inputs. The converter now shares a single `PdfPipelineOptions` instance across PDF, IMAGE, HTML, MD, DOCX, and PPTX `FormatOption`s. SimplePipeline-backed formats ignore the PDF-specific fields; `ConvertPipelineOptions`-level enrichments (picture description / classification / chart extraction) now run uniformly. HTML and Markdown additionally receive `HTMLBackendOptions` / `MarkdownBackendOptions` gated on `fetch_remote_images`.

haiku_rag_slim/haiku/rag/chat/app.py

@@ -233,9 +233,11 @@ class ChatApp(App):
                         assert isinstance(event, TextMessageContentEvent)
                         accumulated_text += event.delta
                         if message:
-                            message.update_content(accumulated_text)
+                            await message.append_delta(event.delta)
                             chat_history.scroll_end(animate=False)
                     elif event.type == EventType.TEXT_MESSAGE_END:
+                        if message:
+                            await message.finish_stream()
                         self._messages.append(
                             AssistantMessage(
                                 id=str(uuid.uuid4()),
@@ -308,9 +310,13 @@ class ChatApp(App):
 
         except asyncio.CancelledError:
             chat_history.hide_thinking()
+            if message:
+                await message.finish_stream()
             await chat_history.add_message("assistant", "*Cancelled*")
         except Exception as e:
             chat_history.hide_thinking()
+            if message:
+                await message.finish_stream()
             await chat_history.add_message("assistant", f"Error: {e}")
         finally:
             self._is_processing = False

haiku_rag_slim/haiku/rag/chat/widgets/chat_history.py

@@ -1,8 +1,10 @@
 from typing import TYPE_CHECKING, Any
 
 from textual.containers import Horizontal, VerticalScroll
+from textual.css.query import NoMatches
 from textual.message import Message
 from textual.widgets import Collapsible, LoadingIndicator, Markdown, Static
+from textual.widgets.markdown import MarkdownStream
 
 from haiku.rag.agents.research.models import Citation
 
@@ -17,18 +19,36 @@ class ChatMessage(Static):
     def __init__(self, role: str, content: str = "", **kwargs) -> None:
         super().__init__(**kwargs)
         self.role = role
-        self.content = content
+        self.body_text: str = content
+        self._stream: MarkdownStream | None = None
 
     def compose(self) -> "ComposeResult":
-        prefix = "**You:**" if self.role == "user" else "**Assistant:**"
-        yield Markdown(f"{prefix}\n\n{self.content}", id="message-content")
+        prefix = "You:" if self.role == "user" else "Assistant:"
+        yield Static(prefix, classes="message-prefix")
+        yield Markdown(self.body_text, classes="message-body")
 
-    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}")
+    async def append_delta(self, delta: str) -> None:
+        if not delta:
+            return
+        if self._stream is None:
+            try:
+                body = self.query_one(".message-body", Markdown)
+            except NoMatches:
+                return
+            self._stream = Markdown.get_stream(body)
+        self.body_text += delta
+        await self._stream.write(delta)
+
+    async def finish_stream(self) -> None:
+        if self._stream is None:
+            return
+        await self._stream.stop()
+        self._stream = None
+        try:
+            body = self.query_one(".message-body", Markdown)
+        except NoMatches:
+            return
+        await body.update(self.body_text)
 
 
 class ToolCallWidget(Static):
@@ -216,6 +236,10 @@ class ChatHistory(VerticalScroll):
         padding: 0;
     }
 
+    ChatMessage .message-prefix {
+        text-style: bold;
+    }
+
     /* Tool calls */
     ToolCallWidget {
         margin: 0 0 0 4;

haiku_rag_slim/pyproject.toml

@@ -53,7 +53,7 @@ cohere = ["cohere>=5.21.1"]
 zeroentropy = ["zeroentropy>=0.1.0a11"]
 jina = ["transformers>=4.40.0", "torch>=2.0.0"]
 # TUI (chat and inspect commands)
-tui = ["textual>=8.2.1", "textual-image>=0.8.5"]
+tui = ["textual>=8.2.4", "textual-image>=0.8.5"]
 # Model providers (delegated to pydantic-ai-slim)
 anthropic = ["pydantic-ai-slim[anthropic]"]
 groq = ["pydantic-ai-slim[groq]"]

pyproject.toml

@@ -37,7 +37,7 @@ dependencies = [
 haiku-rag = "haiku.rag.cli:cli"
 
 [project.optional-dependencies]
-tui = ["textual>=1.0.0"]
+tui = ["textual>=8.2.4"]
 s3 = ["haiku.rag-slim[s3]==0.45.0"]
 
 [build-system]