feat(feishu): stream updates on a single card (#1031)

* feat(feishu): stream updates on a single card

* fix(feishu): ensure final message on stream error and warn on missing card ID

- Wrap streaming loop in try/except/finally so a is_final=True outbound
  message is always published, even when the LangGraph stream breaks
  mid-way. This prevents _running_card_ids memory leaks and ensures the
  Feishu card shows a DONE reaction instead of hanging on "Working on it".
- Log a warning when _ensure_running_card gets no message_id back from
  the Feishu reply API, making silent fallback to new-card behavior
  visible in logs.
- Add test_handle_feishu_stream_error_still_sends_final to cover the
  error path.
- Reformat service.py dict comprehension (ruff format, no logic change).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Avoid blocking inbound on Feishu card creation

---------

Co-authored-by: songyaolun <songyaolun@bytedance.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

backend/CLAUDE.md

@@ -251,19 +251,22 @@ Bridges external messaging platforms (Feishu, Slack, Telegram) to the DeerFlow a
 **Architecture**: Channels communicate with the LangGraph Server through `langgraph-sdk` HTTP client (same as the frontend), ensuring threads are created and managed server-side.
 
 **Components**:
-- `message_bus.py` - Async pub/sub hub (`InboundMessage` -> queue -> dispatcher; `OutboundMessage` -> callbacks -> channels)
-- `store.py` - JSON-file persistence mapping `channel_name:chat_id[:topic_id]` -> `thread_id` (keys are `channel:chat` for root conversations and `channel:chat:topic` for threaded conversations)
-- `manager.py` - Core dispatcher: creates threads via `client.threads.create()`, sends messages via `client.runs.wait()`, routes commands
+- `message_bus.py` - Async pub/sub hub (`InboundMessage` → queue → dispatcher; `OutboundMessage` → callbacks → channels)
+- `store.py` - JSON-file persistence mapping `channel_name:chat_id[:topic_id]` → `thread_id` (keys are `channel:chat` for root conversations and `channel:chat:topic` for threaded conversations)
+- `manager.py` - Core dispatcher: creates threads via `client.threads.create()`, routes commands, keeps Slack/Telegram on `client.runs.wait()`, and uses `client.runs.stream(["messages-tuple", "values"])` for Feishu incremental outbound updates
 - `base.py` - Abstract `Channel` base class (start/stop/send lifecycle)
 - `service.py` - Manages lifecycle of all configured channels from `config.yaml`
-- `slack.py` / `feishu.py` / `telegram.py` - Platform-specific implementations
+- `slack.py` / `feishu.py` / `telegram.py` - Platform-specific implementations (`feishu.py` tracks the running card `message_id` in memory and patches the same card in place)
 
 **Message Flow**:
 1. External platform -> Channel impl -> `MessageBus.publish_inbound()`
 2. `ChannelManager._dispatch_loop()` consumes from queue
-3. For chat: look up/create thread on LangGraph Server -> `runs.wait()` -> extract response -> publish outbound
-4. For commands (`/new`, `/status`, `/models`, `/memory`, `/help`): handle locally or query Gateway API
-5. Outbound -> channel callbacks -> platform reply
+3. For chat: look up/create thread on LangGraph Server
+4. Feishu chat: `runs.stream()` → accumulate AI text → publish multiple outbound updates (`is_final=False`) → publish final outbound (`is_final=True`)
+5. Slack/Telegram chat: `runs.wait()` → extract final response → publish outbound
+6. Feishu channel sends one running reply card up front, then patches the same card for each outbound update (card JSON sets `config.update_multi=true` for Feishu's patch API requirement)
+7. For commands (`/new`, `/status`, `/models`, `/memory`, `/help`): handle locally or query Gateway API
+8. Outbound → channel callbacks → platform reply
 
 **Configuration** (`config.yaml` -> `channels`):
 - `langgraph_url` - LangGraph Server URL (default: `http://localhost:2024`)

backend/README.md

@@ -127,6 +127,12 @@ FastAPI application providing REST endpoints for frontend integration:
 | `GET /api/threads/{id}/uploads/list` | List uploaded files |
 | `GET /api/threads/{id}/artifacts/{path}` | Serve generated artifacts |
 
+### IM Channels
+
+The IM bridge supports Feishu, Slack, and Telegram. Slack and Telegram still use the final `runs.wait()` response path, while Feishu now streams through `runs.stream(["messages-tuple", "values"])` and updates a single in-thread card in place.
+
+For Feishu card updates, DeerFlow stores the running card's `message_id` per inbound message and patches that same card until the run finishes, preserving the existing `OK` / `DONE` reaction flow.
+
 ---
 
 ## Quick Start

backend/src/channels/feishu.py

@@ -40,6 +40,11 @@ class FeishuChannel(Channel):
         self._CreateMessageReactionRequest = None
         self._CreateMessageReactionRequestBody = None
         self._Emoji = None
+        self._PatchMessageRequest = None
+        self._PatchMessageRequestBody = None
+        self._background_tasks: set[asyncio.Task] = set()
+        self._running_card_ids: dict[str, str] = {}
+        self._running_card_tasks: dict[str, asyncio.Task] = {}
         self._CreateFileRequest = None
         self._CreateFileRequestBody = None
         self._CreateImageRequest = None
@@ -61,6 +66,8 @@ class FeishuChannel(Channel):
                 CreateMessageRequest,
                 CreateMessageRequestBody,
                 Emoji,
+                PatchMessageRequest,
+                PatchMessageRequestBody,
                 ReplyMessageRequest,
                 ReplyMessageRequestBody,
             )
@@ -76,6 +83,8 @@ class FeishuChannel(Channel):
         self._CreateMessageReactionRequest = CreateMessageReactionRequest
         self._CreateMessageReactionRequestBody = CreateMessageReactionRequestBody
         self._Emoji = Emoji
+        self._PatchMessageRequest = PatchMessageRequest
+        self._PatchMessageRequestBody = PatchMessageRequestBody
         self._CreateFileRequest = CreateFileRequest
         self._CreateFileRequestBody = CreateFileRequestBody
         self._CreateImageRequest = CreateImageRequest
@@ -145,6 +154,12 @@ class FeishuChannel(Channel):
     async def stop(self) -> None:
         self._running = False
         self.bus.unsubscribe_outbound(self._on_outbound)
+        for task in list(self._background_tasks):
+            task.cancel()
+        self._background_tasks.clear()
+        for task in list(self._running_card_tasks.values()):
+            task.cancel()
+        self._running_card_tasks.clear()
         if self._thread:
             self._thread.join(timeout=5)
             self._thread = None
@@ -161,24 +176,11 @@ class FeishuChannel(Channel):
             msg.thread_ts,
             len(msg.text),
         )
-        content = self._build_card_content(msg.text)
 
         last_exc: Exception | None = None
         for attempt in range(_max_retries):
             try:
-                if msg.thread_ts:
-                    # Reply in thread (话题)
-                    request = self._ReplyMessageRequest.builder().message_id(msg.thread_ts).request_body(self._ReplyMessageRequestBody.builder().msg_type("interactive").content(content).reply_in_thread(True).build()).build()
-                    await asyncio.to_thread(self._api_client.im.v1.message.reply, request)
-                else:
-                    # Send new message
-                    request = self._CreateMessageRequest.builder().receive_id_type("chat_id").request_body(self._CreateMessageRequestBody.builder().receive_id(msg.chat_id).msg_type("interactive").content(content).build()).build()
-                    await asyncio.to_thread(self._api_client.im.v1.message.create, request)
-
-                # Add "DONE" reaction to the original message on final reply
-                if msg.is_final and msg.thread_ts:
-                    await self._add_reaction(msg.thread_ts, "DONE")
-
+                await self._send_card_message(msg)
                 return  # success
             except Exception as exc:
                 last_exc = exc
@@ -271,7 +273,7 @@ class FeishuChannel(Channel):
         headers, bold/italic, code blocks, lists, and links.
         """
         card = {
-            "config": {"wide_screen_mode": True},
+            "config": {"wide_screen_mode": True, "update_multi": True},
             "elements": [{"tag": "markdown", "content": text}],
         }
         return json.dumps(card)
@@ -289,18 +291,135 @@ class FeishuChannel(Channel):
         except Exception:
             logger.exception("[Feishu] failed to add reaction '%s' to message %s", emoji_type, message_id)
 
-    async def _send_running_reply(self, message_id: str) -> None:
-        """Reply to a message in-thread with a 'Working on it...' hint."""
+    async def _reply_card(self, message_id: str, text: str) -> str | None:
+        """Reply with an interactive card and return the created card message ID."""
+        if not self._api_client:
+            return None
+
+        content = self._build_card_content(text)
+        request = self._ReplyMessageRequest.builder().message_id(message_id).request_body(self._ReplyMessageRequestBody.builder().msg_type("interactive").content(content).reply_in_thread(True).build()).build()
+        response = await asyncio.to_thread(self._api_client.im.v1.message.reply, request)
+        response_data = getattr(response, "data", None)
+        return getattr(response_data, "message_id", None)
+
+    async def _create_card(self, chat_id: str, text: str) -> None:
+        """Create a new card message in the target chat."""
         if not self._api_client:
             return
+
+        content = self._build_card_content(text)
+        request = self._CreateMessageRequest.builder().receive_id_type("chat_id").request_body(self._CreateMessageRequestBody.builder().receive_id(chat_id).msg_type("interactive").content(content).build()).build()
+        await asyncio.to_thread(self._api_client.im.v1.message.create, request)
+
+    async def _update_card(self, message_id: str, text: str) -> None:
+        """Patch an existing card message in place."""
+        if not self._api_client or not self._PatchMessageRequest:
+            return
+
+        content = self._build_card_content(text)
+        request = self._PatchMessageRequest.builder().message_id(message_id).request_body(self._PatchMessageRequestBody.builder().content(content).build()).build()
+        await asyncio.to_thread(self._api_client.im.v1.message.patch, request)
+
+    def _track_background_task(self, task: asyncio.Task, *, name: str, msg_id: str) -> None:
+        """Keep a strong reference to fire-and-forget tasks and surface errors."""
+        self._background_tasks.add(task)
+        task.add_done_callback(lambda done_task, task_name=name, mid=msg_id: self._finalize_background_task(done_task, task_name, mid))
+
+    def _finalize_background_task(self, task: asyncio.Task, name: str, msg_id: str) -> None:
+        self._background_tasks.discard(task)
+        self._log_task_error(task, name, msg_id)
+
+    async def _create_running_card(self, source_message_id: str, text: str) -> str | None:
+        """Create the running card and cache its message ID when available."""
+        running_card_id = await self._reply_card(source_message_id, text)
+        if running_card_id:
+            self._running_card_ids[source_message_id] = running_card_id
+            logger.info("[Feishu] running card created: source=%s card=%s", source_message_id, running_card_id)
+        else:
+            logger.warning("[Feishu] running card creation returned no message_id for source=%s, subsequent updates will fall back to new replies", source_message_id)
+        return running_card_id
+
+    def _ensure_running_card_started(self, source_message_id: str, text: str = "Working on it...") -> asyncio.Task | None:
+        """Start running-card creation once per source message."""
+        running_card_id = self._running_card_ids.get(source_message_id)
+        if running_card_id:
+            return None
+
+        running_card_task = self._running_card_tasks.get(source_message_id)
+        if running_card_task:
+            return running_card_task
+
+        running_card_task = asyncio.create_task(self._create_running_card(source_message_id, text))
+        self._running_card_tasks[source_message_id] = running_card_task
+        running_card_task.add_done_callback(lambda done_task, mid=source_message_id: self._finalize_running_card_task(mid, done_task))
+        return running_card_task
+
+    def _finalize_running_card_task(self, source_message_id: str, task: asyncio.Task) -> None:
+        if self._running_card_tasks.get(source_message_id) is task:
+            self._running_card_tasks.pop(source_message_id, None)
+        self._log_task_error(task, "create_running_card", source_message_id)
+
+    async def _ensure_running_card(self, source_message_id: str, text: str = "Working on it...") -> str | None:
+        """Ensure the in-thread running card exists and track its message ID."""
+        running_card_id = self._running_card_ids.get(source_message_id)
+        if running_card_id:
+            return running_card_id
+
+        running_card_task = self._ensure_running_card_started(source_message_id, text)
+        if running_card_task is None:
+            return self._running_card_ids.get(source_message_id)
+        return await running_card_task
+
+    async def _send_running_reply(self, message_id: str) -> None:
+        """Reply to a message in-thread with a running card."""
         try:
-            content = self._build_card_content("Working on it...")
-            request = self._ReplyMessageRequest.builder().message_id(message_id).request_body(self._ReplyMessageRequestBody.builder().msg_type("interactive").content(content).reply_in_thread(True).build()).build()
-            await asyncio.to_thread(self._api_client.im.v1.message.reply, request)
-            logger.info("[Feishu] 'Working on it......' reply sent for message %s", message_id)
+            await self._ensure_running_card(message_id)
         except Exception:
             logger.exception("[Feishu] failed to send running reply for message %s", message_id)
 
+    async def _send_card_message(self, msg: OutboundMessage) -> None:
+        """Send or update the Feishu card tied to the current request."""
+        source_message_id = msg.thread_ts
+        if source_message_id:
+            running_card_id = self._running_card_ids.get(source_message_id)
+            awaited_running_card_task = False
+
+            if not running_card_id:
+                running_card_task = self._running_card_tasks.get(source_message_id)
+                if running_card_task:
+                    awaited_running_card_task = True
+                    running_card_id = await running_card_task
+
+            if running_card_id:
+                try:
+                    await self._update_card(running_card_id, msg.text)
+                except Exception:
+                    if not msg.is_final:
+                        raise
+                    logger.exception(
+                        "[Feishu] failed to patch running card %s, falling back to final reply",
+                        running_card_id,
+                    )
+                    await self._reply_card(source_message_id, msg.text)
+                else:
+                    logger.info("[Feishu] running card updated: source=%s card=%s", source_message_id, running_card_id)
+            elif msg.is_final:
+                await self._reply_card(source_message_id, msg.text)
+            elif awaited_running_card_task:
+                logger.warning(
+                    "[Feishu] running card task finished without message_id for source=%s, skipping duplicate non-final creation",
+                    source_message_id,
+                )
+            else:
+                await self._ensure_running_card(source_message_id, msg.text)
+
+            if msg.is_final:
+                self._running_card_ids.pop(source_message_id, None)
+                await self._add_reaction(source_message_id, "DONE")
+            return
+
+        await self._create_card(msg.chat_id, msg.text)
+
     # -- internal ----------------------------------------------------------
 
     @staticmethod
@@ -313,6 +432,25 @@ class FeishuChannel(Channel):
         except Exception:
             pass
 
+    @staticmethod
+    def _log_task_error(task: asyncio.Task, name: str, msg_id: str) -> None:
+        """Callback for background asyncio tasks to surface errors."""
+        try:
+            exc = task.exception()
+            if exc:
+                logger.error("[Feishu] %s failed for msg_id=%s: %s", name, msg_id, exc)
+        except asyncio.CancelledError:
+            logger.info("[Feishu] %s cancelled for msg_id=%s", name, msg_id)
+        except Exception:
+            pass
+
+    async def _prepare_inbound(self, msg_id: str, inbound) -> None:
+        """Kick off Feishu side effects without delaying inbound dispatch."""
+        reaction_task = asyncio.create_task(self._add_reaction(msg_id, "OK"))
+        self._track_background_task(reaction_task, name="add_reaction", msg_id=msg_id)
+        self._ensure_running_card_started(msg_id)
+        await self.bus.publish_inbound(inbound)
+
     def _on_message(self, event) -> None:
         """Called by lark-oapi when a message is received (runs in lark thread)."""
         try:
@@ -364,14 +502,8 @@ class FeishuChannel(Channel):
             # Schedule on the async event loop
             if self._main_loop and self._main_loop.is_running():
                 logger.info("[Feishu] publishing inbound message to bus (type=%s, msg_id=%s)", msg_type.value, msg_id)
-                # Schedule all coroutines and attach error logging to futures
-                for name, coro in [
-                    ("add_reaction", self._add_reaction(msg_id, "OK")),
-                    ("send_running_reply", self._send_running_reply(msg_id)),
-                    ("publish_inbound", self.bus.publish_inbound(inbound)),
-                ]:
-                    fut = asyncio.run_coroutine_threadsafe(coro, self._main_loop)
-                    fut.add_done_callback(lambda f, n=name, mid=msg_id: self._log_future_error(f, n, mid))
+                fut = asyncio.run_coroutine_threadsafe(self._prepare_inbound(msg_id, inbound), self._main_loop)
+                fut.add_done_callback(lambda f, mid=msg_id: self._log_future_error(f, "prepare_inbound", mid))
             else:
                 logger.warning("[Feishu] main loop not running, cannot publish inbound message")
         except Exception:

backend/src/channels/manager.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 import asyncio
 import logging
 import mimetypes
+import time
 from collections.abc import Mapping
 from typing import Any
 
@@ -23,6 +24,7 @@ DEFAULT_RUN_CONTEXT: dict[str, Any] = {
     "is_plan_mode": False,
     "subagent_enabled": False,
 }
+STREAM_UPDATE_MIN_INTERVAL_SECONDS = 0.35
 
 
 def _as_dict(value: Any) -> dict[str, Any]:
@@ -92,6 +94,98 @@ def _extract_response_text(result: dict | list) -> str:
     return ""
 
 
+def _extract_text_content(content: Any) -> str:
+    """Extract text from a streaming payload content field."""
+    if isinstance(content, str):
+        return content
+    if isinstance(content, list):
+        parts: list[str] = []
+        for block in content:
+            if isinstance(block, str):
+                parts.append(block)
+            elif isinstance(block, Mapping):
+                text = block.get("text")
+                if isinstance(text, str):
+                    parts.append(text)
+                else:
+                    nested = block.get("content")
+                    if isinstance(nested, str):
+                        parts.append(nested)
+        return "".join(parts)
+    if isinstance(content, Mapping):
+        for key in ("text", "content"):
+            value = content.get(key)
+            if isinstance(value, str):
+                return value
+    return ""
+
+
+def _merge_stream_text(existing: str, chunk: str) -> str:
+    """Merge either delta text or cumulative text into a single snapshot."""
+    if not chunk:
+        return existing
+    if not existing or chunk == existing:
+        return chunk or existing
+    if chunk.startswith(existing):
+        return chunk
+    if existing.endswith(chunk):
+        return existing
+    return existing + chunk
+
+
+def _extract_stream_message_id(payload: Any, metadata: Any) -> str | None:
+    """Best-effort extraction of the streamed AI message identifier."""
+    candidates = [payload, metadata]
+    if isinstance(payload, Mapping):
+        candidates.append(payload.get("kwargs"))
+
+    for candidate in candidates:
+        if not isinstance(candidate, Mapping):
+            continue
+        for key in ("id", "message_id"):
+            value = candidate.get(key)
+            if isinstance(value, str) and value:
+                return value
+    return None
+
+
+def _accumulate_stream_text(
+    buffers: dict[str, str],
+    current_message_id: str | None,
+    event_data: Any,
+) -> tuple[str | None, str | None]:
+    """Convert a ``messages-tuple`` event into the latest displayable AI text."""
+    payload = event_data
+    metadata: Any = None
+    if isinstance(event_data, (list, tuple)):
+        if event_data:
+            payload = event_data[0]
+        if len(event_data) > 1:
+            metadata = event_data[1]
+
+    if isinstance(payload, str):
+        message_id = current_message_id or "__default__"
+        buffers[message_id] = _merge_stream_text(buffers.get(message_id, ""), payload)
+        return buffers[message_id], message_id
+
+    if not isinstance(payload, Mapping):
+        return None, current_message_id
+
+    payload_type = str(payload.get("type", "")).lower()
+    if "tool" in payload_type:
+        return None, current_message_id
+
+    text = _extract_text_content(payload.get("content"))
+    if not text and isinstance(payload.get("kwargs"), Mapping):
+        text = _extract_text_content(payload["kwargs"].get("content"))
+    if not text:
+        return None, current_message_id
+
+    message_id = _extract_stream_message_id(payload, metadata) or current_message_id or "__default__"
+    buffers[message_id] = _merge_stream_text(buffers.get(message_id, ""), text)
+    return buffers[message_id], message_id
+
+
 def _extract_artifacts(result: dict | list) -> list[str]:
     """Extract artifact paths from the last AI response cycle only.
 
@@ -185,6 +279,33 @@ def _resolve_attachments(thread_id: str, artifacts: list[str]) -> list[ResolvedA
     return attachments
 
 
+def _prepare_artifact_delivery(
+    thread_id: str,
+    response_text: str,
+    artifacts: list[str],
+) -> tuple[str, list[ResolvedAttachment]]:
+    """Resolve attachments and append filename fallbacks to the text response."""
+    attachments: list[ResolvedAttachment] = []
+    if not artifacts:
+        return response_text, attachments
+
+    attachments = _resolve_attachments(thread_id, artifacts)
+    resolved_virtuals = {attachment.virtual_path for attachment in attachments}
+    unresolved = [path for path in artifacts if path not in resolved_virtuals]
+
+    if unresolved:
+        artifact_text = _format_artifact_text(unresolved)
+        response_text = (response_text + "\n\n" + artifact_text) if response_text else artifact_text
+
+    # Always include resolved attachment filenames as a text fallback so files
+    # remain discoverable even when the upload is skipped or fails.
+    if attachments:
+        resolved_text = _format_artifact_text([attachment.virtual_path for attachment in attachments])
+        response_text = (response_text + "\n\n" + resolved_text) if response_text else resolved_text
+
+    return response_text, attachments
+
+
 class ChannelManager:
     """Core dispatcher that bridges IM channels to the DeerFlow agent.
 
@@ -363,6 +484,17 @@ class ChannelManager:
             thread_id = await self._create_thread(client, msg)
 
         assistant_id, run_config, run_context = self._resolve_run_params(msg, thread_id)
+        if msg.channel_name == "feishu":
+            await self._handle_streaming_chat(
+                client,
+                msg,
+                thread_id,
+                assistant_id,
+                run_config,
+                run_context,
+            )
+            return
+
         logger.info("[Manager] invoking runs.wait(thread_id=%s, text=%r)", thread_id, msg.text[:100])
         result = await client.runs.wait(
             thread_id,
@@ -382,20 +514,7 @@ class ChannelManager:
             len(artifacts),
         )
 
-        # Resolve artifact virtual paths to actual files for channel upload
-        attachments: list[ResolvedAttachment] = []
-        if artifacts:
-            attachments = _resolve_attachments(thread_id, artifacts)
-            resolved_virtuals = {a.virtual_path for a in attachments}
-            unresolved = [p for p in artifacts if p not in resolved_virtuals]
-            if unresolved:
-                artifact_text = _format_artifact_text(unresolved)
-                response_text = (response_text + "\n\n" + artifact_text) if response_text else artifact_text
-            # Always include resolved attachment filenames as a text fallback so
-            # files remain discoverable even when the upload is skipped or fails.
-            if attachments:
-                resolved_text = _format_artifact_text([a.virtual_path for a in attachments])
-                response_text = (response_text + "\n\n" + resolved_text) if response_text else resolved_text
+        response_text, attachments = _prepare_artifact_delivery(thread_id, response_text, artifacts)
 
         if not response_text:
             if attachments:
@@ -415,6 +534,103 @@ class ChannelManager:
         logger.info("[Manager] publishing outbound message to bus: channel=%s, chat_id=%s", msg.channel_name, msg.chat_id)
         await self.bus.publish_outbound(outbound)
 
+    async def _handle_streaming_chat(
+        self,
+        client,
+        msg: InboundMessage,
+        thread_id: str,
+        assistant_id: str,
+        run_config: dict[str, Any],
+        run_context: dict[str, Any],
+    ) -> None:
+        logger.info("[Manager] invoking runs.stream(thread_id=%s, text=%r)", thread_id, msg.text[:100])
+
+        last_values: dict[str, Any] | list | None = None
+        streamed_buffers: dict[str, str] = {}
+        current_message_id: str | None = None
+        latest_text = ""
+        last_published_text = ""
+        last_publish_at = 0.0
+        stream_error: BaseException | None = None
+
+        try:
+            async for chunk in client.runs.stream(
+                thread_id,
+                assistant_id,
+                input={"messages": [{"role": "human", "content": msg.text}]},
+                config=run_config,
+                context=run_context,
+                stream_mode=["messages-tuple", "values"],
+            ):
+                event = getattr(chunk, "event", "")
+                data = getattr(chunk, "data", None)
+
+                if event == "messages-tuple":
+                    accumulated_text, current_message_id = _accumulate_stream_text(streamed_buffers, current_message_id, data)
+                    if accumulated_text:
+                        latest_text = accumulated_text
+                elif event == "values" and isinstance(data, (dict, list)):
+                    last_values = data
+                    snapshot_text = _extract_response_text(data)
+                    if snapshot_text:
+                        latest_text = snapshot_text
+
+                if not latest_text or latest_text == last_published_text:
+                    continue
+
+                now = time.monotonic()
+                if last_published_text and now - last_publish_at < STREAM_UPDATE_MIN_INTERVAL_SECONDS:
+                    continue
+
+                await self.bus.publish_outbound(
+                    OutboundMessage(
+                        channel_name=msg.channel_name,
+                        chat_id=msg.chat_id,
+                        thread_id=thread_id,
+                        text=latest_text,
+                        is_final=False,
+                        thread_ts=msg.thread_ts,
+                    )
+                )
+                last_published_text = latest_text
+                last_publish_at = now
+        except Exception as exc:
+            stream_error = exc
+            logger.exception("[Manager] streaming error: thread_id=%s", thread_id)
+        finally:
+            result = last_values if last_values is not None else {"messages": [{"type": "ai", "content": latest_text}]}
+            response_text = _extract_response_text(result)
+            artifacts = _extract_artifacts(result)
+            response_text, attachments = _prepare_artifact_delivery(thread_id, response_text, artifacts)
+
+            if not response_text:
+                if attachments:
+                    response_text = _format_artifact_text([attachment.virtual_path for attachment in attachments])
+                elif stream_error:
+                    response_text = "An error occurred while processing your request. Please try again."
+                else:
+                    response_text = latest_text or "(No response from agent)"
+
+            logger.info(
+                "[Manager] streaming response completed: thread_id=%s, response_len=%d, artifacts=%d, error=%s",
+                thread_id,
+                len(response_text),
+                len(artifacts),
+                stream_error,
+            )
+            await self.bus.publish_outbound(
+                OutboundMessage(
+                    channel_name=msg.channel_name,
+                    chat_id=msg.chat_id,
+                    thread_id=thread_id,
+                    text=response_text,
+                    artifacts=artifacts,
+                    attachments=attachments,
+                    is_final=True,
+                    thread_ts=msg.thread_ts,
+                )
+            )
+
     # -- command handling --------------------------------------------------
 
     async def _handle_command(self, msg: InboundMessage) -> None:

backend/src/channels/service.py

@@ -33,11 +33,7 @@ class ChannelService:
         langgraph_url = config.pop("langgraph_url", None) or "http://localhost:2024"
         gateway_url = config.pop("gateway_url", None) or "http://localhost:8001"
         default_session = config.pop("session", None)
-        channel_sessions = {
-            name: channel_config.get("session")
-            for name, channel_config in config.items()
-            if isinstance(channel_config, dict)
-        }
+        channel_sessions = {name: channel_config.get("session") for name, channel_config in config.items() if isinstance(channel_config, dict)}
         self.manager = ChannelManager(
             bus=self.bus,
             store=self.store,

backend/tests/test_channels.py

@@ -3,8 +3,10 @@
 from __future__ import annotations
 
 import asyncio
+import json
 import tempfile
 from pathlib import Path
+from types import SimpleNamespace
 from unittest.mock import AsyncMock, MagicMock
 
 import pytest
@@ -399,6 +401,18 @@ def _make_mock_langgraph_client(thread_id="test-thread-123", run_result=None):
     return mock_client
 
 
+def _make_stream_part(event: str, data):
+    return SimpleNamespace(event=event, data=data)
+
+
+def _make_async_iterator(items):
+    async def iterator():
+        for item in items:
+            yield item
+
+    return iterator()
+
+
 class TestChannelManager:
     def test_handle_chat_creates_thread(self):
         from src.channels.manager import ChannelManager
@@ -550,6 +564,126 @@ class TestChannelManager:
 
         _run(go())
 
+    def test_handle_feishu_chat_streams_multiple_outbound_updates(self, monkeypatch):
+        from src.channels.manager import ChannelManager
+
+        monkeypatch.setattr("src.channels.manager.STREAM_UPDATE_MIN_INTERVAL_SECONDS", 0.0)
+
+        async def go():
+            bus = MessageBus()
+            store = ChannelStore(path=Path(tempfile.mkdtemp()) / "store.json")
+            manager = ChannelManager(bus=bus, store=store)
+
+            outbound_received = []
+
+            async def capture_outbound(msg):
+                outbound_received.append(msg)
+
+            bus.subscribe_outbound(capture_outbound)
+
+            stream_events = [
+                _make_stream_part(
+                    "messages-tuple",
+                    [
+                        {"id": "ai-1", "content": "Hello", "type": "AIMessageChunk"},
+                        {"langgraph_node": "agent"},
+                    ],
+                ),
+                _make_stream_part(
+                    "messages-tuple",
+                    [
+                        {"id": "ai-1", "content": " world", "type": "AIMessageChunk"},
+                        {"langgraph_node": "agent"},
+                    ],
+                ),
+                _make_stream_part(
+                    "values",
+                    {
+                        "messages": [
+                            {"type": "human", "content": "hi"},
+                            {"type": "ai", "content": "Hello world"},
+                        ],
+                        "artifacts": [],
+                    },
+                ),
+            ]
+
+            mock_client = _make_mock_langgraph_client()
+            mock_client.runs.stream = MagicMock(return_value=_make_async_iterator(stream_events))
+            manager._client = mock_client
+
+            await manager.start()
+
+            inbound = InboundMessage(
+                channel_name="feishu",
+                chat_id="chat1",
+                user_id="user1",
+                text="hi",
+                thread_ts="om-source-1",
+            )
+            await bus.publish_inbound(inbound)
+            await _wait_for(lambda: len(outbound_received) >= 3)
+            await manager.stop()
+
+            mock_client.runs.stream.assert_called_once()
+            assert [msg.text for msg in outbound_received] == ["Hello", "Hello world", "Hello world"]
+            assert [msg.is_final for msg in outbound_received] == [False, False, True]
+            assert all(msg.thread_ts == "om-source-1" for msg in outbound_received)
+
+        _run(go())
+
+    def test_handle_feishu_stream_error_still_sends_final(self, monkeypatch):
+        """When the stream raises mid-way, a final outbound with is_final=True must still be published."""
+        from src.channels.manager import ChannelManager
+
+        monkeypatch.setattr("src.channels.manager.STREAM_UPDATE_MIN_INTERVAL_SECONDS", 0.0)
+
+        async def go():
+            bus = MessageBus()
+            store = ChannelStore(path=Path(tempfile.mkdtemp()) / "store.json")
+            manager = ChannelManager(bus=bus, store=store)
+
+            outbound_received = []
+
+            async def capture_outbound(msg):
+                outbound_received.append(msg)
+
+            bus.subscribe_outbound(capture_outbound)
+
+            async def _failing_stream():
+                yield _make_stream_part(
+                    "messages-tuple",
+                    [
+                        {"id": "ai-1", "content": "Partial", "type": "AIMessageChunk"},
+                        {"langgraph_node": "agent"},
+                    ],
+                )
+                raise ConnectionError("stream broken")
+
+            mock_client = _make_mock_langgraph_client()
+            mock_client.runs.stream = MagicMock(return_value=_failing_stream())
+            manager._client = mock_client
+
+            await manager.start()
+
+            inbound = InboundMessage(
+                channel_name="feishu",
+                chat_id="chat1",
+                user_id="user1",
+                text="hi",
+                thread_ts="om-source-1",
+            )
+            await bus.publish_inbound(inbound)
+            await _wait_for(lambda: any(m.is_final for m in outbound_received))
+            await manager.stop()
+
+            # Should have at least one intermediate and one final message
+            final_msgs = [m for m in outbound_received if m.is_final]
+            assert len(final_msgs) == 1
+            assert final_msgs[0].thread_ts == "om-source-1"
+
+        _run(go())
+
     def test_handle_command_help(self):
         from src.channels.manager import ChannelManager
 
@@ -1092,6 +1226,180 @@ class TestHandleChatWithArtifacts:
         _run(go())
 
 
+class TestFeishuChannel:
+    def test_prepare_inbound_publishes_without_waiting_for_running_card(self):
+        from src.channels.feishu import FeishuChannel
+
+        async def go():
+            bus = MessageBus()
+            bus.publish_inbound = AsyncMock()
+            channel = FeishuChannel(bus, config={})
+
+            reply_started = asyncio.Event()
+            release_reply = asyncio.Event()
+
+            async def slow_reply(message_id: str, text: str) -> str:
+                reply_started.set()
+                await release_reply.wait()
+                return "om-running-card"
+
+            channel._add_reaction = AsyncMock()
+            channel._reply_card = AsyncMock(side_effect=slow_reply)
+
+            inbound = InboundMessage(
+                channel_name="feishu",
+                chat_id="chat-1",
+                user_id="user-1",
+                text="hello",
+                thread_ts="om-source-msg",
+            )
+
+            prepare_task = asyncio.create_task(channel._prepare_inbound("om-source-msg", inbound))
+
+            await _wait_for(lambda: bus.publish_inbound.await_count == 1)
+            await prepare_task
+
+            assert reply_started.is_set()
+            assert "om-source-msg" in channel._running_card_tasks
+            assert channel._reply_card.await_count == 1
+
+            release_reply.set()
+            await _wait_for(lambda: channel._running_card_ids.get("om-source-msg") == "om-running-card")
+            await _wait_for(lambda: "om-source-msg" not in channel._running_card_tasks)
+
+        _run(go())
+
+    def test_prepare_inbound_and_send_share_running_card_task(self):
+        from src.channels.feishu import FeishuChannel
+
+        async def go():
+            bus = MessageBus()
+            bus.publish_inbound = AsyncMock()
+            channel = FeishuChannel(bus, config={})
+            channel._api_client = MagicMock()
+
+            reply_started = asyncio.Event()
+            release_reply = asyncio.Event()
+
+            async def slow_reply(message_id: str, text: str) -> str:
+                reply_started.set()
+                await release_reply.wait()
+                return "om-running-card"
+
+            channel._add_reaction = AsyncMock()
+            channel._reply_card = AsyncMock(side_effect=slow_reply)
+            channel._update_card = AsyncMock()
+
+            inbound = InboundMessage(
+                channel_name="feishu",
+                chat_id="chat-1",
+                user_id="user-1",
+                text="hello",
+                thread_ts="om-source-msg",
+            )
+
+            prepare_task = asyncio.create_task(channel._prepare_inbound("om-source-msg", inbound))
+            await _wait_for(lambda: bus.publish_inbound.await_count == 1)
+            await _wait_for(reply_started.is_set)
+
+            send_task = asyncio.create_task(
+                channel.send(
+                    OutboundMessage(
+                        channel_name="feishu",
+                        chat_id="chat-1",
+                        thread_id="thread-1",
+                        text="Hello",
+                        is_final=False,
+                        thread_ts="om-source-msg",
+                    )
+                )
+            )
+
+            await asyncio.sleep(0)
+            assert channel._reply_card.await_count == 1
+
+            release_reply.set()
+            await prepare_task
+            await send_task
+
+            assert channel._reply_card.await_count == 1
+            channel._update_card.assert_awaited_once_with("om-running-card", "Hello")
+            assert "om-source-msg" not in channel._running_card_tasks
+
+        _run(go())
+
+    def test_streaming_reuses_single_running_card(self):
+        from lark_oapi.api.im.v1 import (
+            CreateMessageReactionRequest,
+            CreateMessageReactionRequestBody,
+            Emoji,
+            PatchMessageRequest,
+            PatchMessageRequestBody,
+            ReplyMessageRequest,
+            ReplyMessageRequestBody,
+        )
+
+        from src.channels.feishu import FeishuChannel
+
+        async def go():
+            bus = MessageBus()
+            channel = FeishuChannel(bus, config={})
+
+            channel._api_client = MagicMock()
+            channel._ReplyMessageRequest = ReplyMessageRequest
+            channel._ReplyMessageRequestBody = ReplyMessageRequestBody
+            channel._PatchMessageRequest = PatchMessageRequest
+            channel._PatchMessageRequestBody = PatchMessageRequestBody
+            channel._CreateMessageReactionRequest = CreateMessageReactionRequest
+            channel._CreateMessageReactionRequestBody = CreateMessageReactionRequestBody
+            channel._Emoji = Emoji
+
+            reply_response = MagicMock()
+            reply_response.data.message_id = "om-running-card"
+            channel._api_client.im.v1.message.reply = MagicMock(return_value=reply_response)
+            channel._api_client.im.v1.message.patch = MagicMock()
+            channel._api_client.im.v1.message_reaction.create = MagicMock()
+
+            await channel._send_running_reply("om-source-msg")
+
+            await channel.send(
+                OutboundMessage(
+                    channel_name="feishu",
+                    chat_id="chat-1",
+                    thread_id="thread-1",
+                    text="Hello",
+                    is_final=False,
+                    thread_ts="om-source-msg",
+                )
+            )
+            await channel.send(
+                OutboundMessage(
+                    channel_name="feishu",
+                    chat_id="chat-1",
+                    thread_id="thread-1",
+                    text="Hello world",
+                    is_final=True,
+                    thread_ts="om-source-msg",
+                )
+            )
+
+            assert channel._api_client.im.v1.message.reply.call_count == 1
+            assert channel._api_client.im.v1.message.patch.call_count == 2
+            assert channel._api_client.im.v1.message_reaction.create.call_count == 1
+            assert "om-source-msg" not in channel._running_card_ids
+            assert "om-source-msg" not in channel._running_card_tasks
+
+            first_patch_request = channel._api_client.im.v1.message.patch.call_args_list[0].args[0]
+            final_patch_request = channel._api_client.im.v1.message.patch.call_args_list[1].args[0]
+            assert first_patch_request.message_id == "om-running-card"
+            assert final_patch_request.message_id == "om-running-card"
+            assert json.loads(first_patch_request.body.content)["elements"][0]["content"] == "Hello"
+            assert json.loads(final_patch_request.body.content)["elements"][0]["content"] == "Hello world"
+            assert json.loads(final_patch_request.body.content)["config"]["update_multi"] is True
+
+        _run(go())
+
+
 class TestChannelService:
     def test_get_status_no_channels(self):
         from src.channels.service import ChannelService