The architecture has been updated

hermes_code/gateway/platforms/slack.py

@@ -0,0 +1,852 @@
+"""
+Slack platform adapter.
+
+Uses slack-bolt (Python) with Socket Mode for:
+- Receiving messages from channels and DMs
+- Sending responses back
+- Handling slash commands
+- Thread support
+"""
+
+import asyncio
+import logging
+import os
+import re
+from typing import Dict, List, Optional, Any
+
+try:
+    from slack_bolt.async_app import AsyncApp
+    from slack_bolt.adapter.socket_mode.async_handler import AsyncSocketModeHandler
+    from slack_sdk.web.async_client import AsyncWebClient
+    SLACK_AVAILABLE = True
+except ImportError:
+    SLACK_AVAILABLE = False
+    AsyncApp = Any
+    AsyncSocketModeHandler = Any
+    AsyncWebClient = Any
+
+import sys
+from pathlib import Path as _Path
+sys.path.insert(0, str(_Path(__file__).resolve().parents[2]))
+
+from gateway.config import Platform, PlatformConfig
+from gateway.platforms.base import (
+    BasePlatformAdapter,
+    MessageEvent,
+    MessageType,
+    SendResult,
+    SUPPORTED_DOCUMENT_TYPES,
+    cache_document_from_bytes,
+    cache_image_from_url,
+    cache_audio_from_url,
+)
+
+
+logger = logging.getLogger(__name__)
+
+
+def check_slack_requirements() -> bool:
+    """Check if Slack dependencies are available."""
+    return SLACK_AVAILABLE
+
+
+class SlackAdapter(BasePlatformAdapter):
+    """
+    Slack bot adapter using Socket Mode.
+
+    Requires two tokens:
+      - SLACK_BOT_TOKEN (xoxb-...) for API calls
+      - SLACK_APP_TOKEN (xapp-...) for Socket Mode connection
+
+    Features:
+      - DMs and channel messages (mention-gated in channels)
+      - Thread support
+      - File/image/audio attachments
+      - Slash commands (/hermes)
+      - Typing indicators (not natively supported by Slack bots)
+    """
+
+    MAX_MESSAGE_LENGTH = 39000  # Slack API allows 40,000 chars; leave margin
+
+    def __init__(self, config: PlatformConfig):
+        super().__init__(config, Platform.SLACK)
+        self._app: Optional[AsyncApp] = None
+        self._handler: Optional[AsyncSocketModeHandler] = None
+        self._bot_user_id: Optional[str] = None
+        self._user_name_cache: Dict[str, str] = {}  # user_id → display name
+
+    async def connect(self) -> bool:
+        """Connect to Slack via Socket Mode."""
+        if not SLACK_AVAILABLE:
+            logger.error(
+                "[Slack] slack-bolt not installed. Run: pip install slack-bolt",
+            )
+            return False
+
+        bot_token = self.config.token
+        app_token = os.getenv("SLACK_APP_TOKEN")
+
+        if not bot_token:
+            logger.error("[Slack] SLACK_BOT_TOKEN not set")
+            return False
+        if not app_token:
+            logger.error("[Slack] SLACK_APP_TOKEN not set")
+            return False
+
+        try:
+            self._app = AsyncApp(token=bot_token)
+
+            # Get our own bot user ID for mention detection
+            auth_response = await self._app.client.auth_test()
+            self._bot_user_id = auth_response.get("user_id")
+            bot_name = auth_response.get("user", "unknown")
+
+            # Register message event handler
+            @self._app.event("message")
+            async def handle_message_event(event, say):
+                await self._handle_slack_message(event)
+
+            # Acknowledge app_mention events to prevent Bolt 404 errors.
+            # The "message" handler above already processes @mentions in
+            # channels, so this is intentionally a no-op to avoid duplicates.
+            @self._app.event("app_mention")
+            async def handle_app_mention(event, say):
+                pass
+
+            # Register slash command handler
+            @self._app.command("/hermes")
+            async def handle_hermes_command(ack, command):
+                await ack()
+                await self._handle_slash_command(command)
+
+            # Start Socket Mode handler in background
+            self._handler = AsyncSocketModeHandler(self._app, app_token)
+            asyncio.create_task(self._handler.start_async())
+
+            self._running = True
+            logger.info("[Slack] Connected as @%s (Socket Mode)", bot_name)
+            return True
+
+        except Exception as e:  # pragma: no cover - defensive logging
+            logger.error("[Slack] Connection failed: %s", e, exc_info=True)
+            return False
+
+    async def disconnect(self) -> None:
+        """Disconnect from Slack."""
+        if self._handler:
+            try:
+                await self._handler.close_async()
+            except Exception as e:  # pragma: no cover - defensive logging
+                logger.warning("[Slack] Error while closing Socket Mode handler: %s", e, exc_info=True)
+        self._running = False
+        logger.info("[Slack] Disconnected")
+
+    async def send(
+        self,
+        chat_id: str,
+        content: str,
+        reply_to: Optional[str] = None,
+        metadata: Optional[Dict[str, Any]] = None,
+    ) -> SendResult:
+        """Send a message to a Slack channel or DM."""
+        if not self._app:
+            return SendResult(success=False, error="Not connected")
+
+        try:
+            # Convert standard markdown → Slack mrkdwn
+            formatted = self.format_message(content)
+
+            # Split long messages, preserving code block boundaries
+            chunks = self.truncate_message(formatted, self.MAX_MESSAGE_LENGTH)
+
+            thread_ts = self._resolve_thread_ts(reply_to, metadata)
+            last_result = None
+
+            # reply_broadcast: also post thread replies to the main channel.
+            # Controlled via platform config: gateway.slack.reply_broadcast
+            broadcast = self.config.extra.get("reply_broadcast", False)
+
+            for i, chunk in enumerate(chunks):
+                kwargs = {
+                    "channel": chat_id,
+                    "text": chunk,
+                }
+                if thread_ts:
+                    kwargs["thread_ts"] = thread_ts
+                    # Only broadcast the first chunk of the first reply
+                    if broadcast and i == 0:
+                        kwargs["reply_broadcast"] = True
+
+                last_result = await self._app.client.chat_postMessage(**kwargs)
+
+            return SendResult(
+                success=True,
+                message_id=last_result.get("ts") if last_result else None,
+                raw_response=last_result,
+            )
+
+        except Exception as e:  # pragma: no cover - defensive logging
+            logger.error("[Slack] Send error: %s", e, exc_info=True)
+            return SendResult(success=False, error=str(e))
+
+    async def edit_message(
+        self,
+        chat_id: str,
+        message_id: str,
+        content: str,
+    ) -> SendResult:
+        """Edit a previously sent Slack message."""
+        if not self._app:
+            return SendResult(success=False, error="Not connected")
+        try:
+            await self._app.client.chat_update(
+                channel=chat_id,
+                ts=message_id,
+                text=content,
+            )
+            return SendResult(success=True, message_id=message_id)
+        except Exception as e:  # pragma: no cover - defensive logging
+            logger.error(
+                "[Slack] Failed to edit message %s in channel %s: %s",
+                message_id,
+                chat_id,
+                e,
+                exc_info=True,
+            )
+            return SendResult(success=False, error=str(e))
+
+    async def send_typing(self, chat_id: str, metadata=None) -> None:
+        """Show a typing/status indicator using assistant.threads.setStatus.
+
+        Displays "is thinking..." next to the bot name in a thread.
+        Requires the assistant:write or chat:write scope.
+        Auto-clears when the bot sends a reply to the thread.
+        """
+        if not self._app:
+            return
+
+        thread_ts = None
+        if metadata:
+            thread_ts = metadata.get("thread_id") or metadata.get("thread_ts")
+
+        if not thread_ts:
+            return  # Can only set status in a thread context
+
+        try:
+            await self._app.client.assistant_threads_setStatus(
+                channel_id=chat_id,
+                thread_ts=thread_ts,
+                status="is thinking...",
+            )
+        except Exception as e:
+            # Silently ignore — may lack assistant:write scope or not be
+            # in an assistant-enabled context. Falls back to reactions.
+            logger.debug("[Slack] assistant.threads.setStatus failed: %s", e)
+
+    def _resolve_thread_ts(
+        self,
+        reply_to: Optional[str] = None,
+        metadata: Optional[Dict[str, Any]] = None,
+    ) -> Optional[str]:
+        """Resolve the correct thread_ts for a Slack API call.
+
+        Prefers metadata thread_id (the thread parent's ts, set by the
+        gateway) over reply_to (which may be a child message's ts).
+        """
+        if metadata:
+            if metadata.get("thread_id"):
+                return metadata["thread_id"]
+            if metadata.get("thread_ts"):
+                return metadata["thread_ts"]
+        return reply_to
+
+    async def _upload_file(
+        self,
+        chat_id: str,
+        file_path: str,
+        caption: Optional[str] = None,
+        reply_to: Optional[str] = None,
+        metadata: Optional[Dict[str, Any]] = None,
+    ) -> SendResult:
+        """Upload a local file to Slack."""
+        if not self._app:
+            return SendResult(success=False, error="Not connected")
+
+        if not os.path.exists(file_path):
+            raise FileNotFoundError(f"File not found: {file_path}")
+
+        result = await self._app.client.files_upload_v2(
+            channel=chat_id,
+            file=file_path,
+            filename=os.path.basename(file_path),
+            initial_comment=caption or "",
+            thread_ts=self._resolve_thread_ts(reply_to, metadata),
+        )
+        return SendResult(success=True, raw_response=result)
+
+    # ----- Markdown → mrkdwn conversion -----
+
+    def format_message(self, content: str) -> str:
+        """Convert standard markdown to Slack mrkdwn format.
+
+        Protected regions (code blocks, inline code) are extracted first so
+        their contents are never modified.  Standard markdown constructs
+        (headers, bold, italic, links) are translated to mrkdwn syntax.
+        """
+        if not content:
+            return content
+
+        placeholders: dict = {}
+        counter = [0]
+
+        def _ph(value: str) -> str:
+            """Stash value behind a placeholder that survives later passes."""
+            key = f"\x00SL{counter[0]}\x00"
+            counter[0] += 1
+            placeholders[key] = value
+            return key
+
+        text = content
+
+        # 1) Protect fenced code blocks (``` ... ```)
+        text = re.sub(
+            r'(```(?:[^\n]*\n)?[\s\S]*?```)',
+            lambda m: _ph(m.group(0)),
+            text,
+        )
+
+        # 2) Protect inline code (`...`)
+        text = re.sub(r'(`[^`]+`)', lambda m: _ph(m.group(0)), text)
+
+        # 3) Convert markdown links [text](url) → <url|text>
+        text = re.sub(
+            r'\[([^\]]+)\]\(([^)]+)\)',
+            lambda m: _ph(f'<{m.group(2)}|{m.group(1)}>'),
+            text,
+        )
+
+        # 4) Convert headers (## Title) → *Title* (bold)
+        def _convert_header(m):
+            inner = m.group(1).strip()
+            # Strip redundant bold markers inside a header
+            inner = re.sub(r'\*\*(.+?)\*\*', r'\1', inner)
+            return _ph(f'*{inner}*')
+
+        text = re.sub(
+            r'^#{1,6}\s+(.+)$', _convert_header, text, flags=re.MULTILINE
+        )
+
+        # 5) Convert bold: **text** → *text* (Slack bold)
+        text = re.sub(
+            r'\*\*(.+?)\*\*',
+            lambda m: _ph(f'*{m.group(1)}*'),
+            text,
+        )
+
+        # 6) Convert italic: _text_ stays as _text_ (already Slack italic)
+        #    Single *text* → _text_ (Slack italic)
+        text = re.sub(
+            r'(?<!\*)\*([^*\n]+)\*(?!\*)',
+            lambda m: _ph(f'_{m.group(1)}_'),
+            text,
+        )
+
+        # 7) Convert strikethrough: ~~text~~ → ~text~
+        text = re.sub(
+            r'~~(.+?)~~',
+            lambda m: _ph(f'~{m.group(1)}~'),
+            text,
+        )
+
+        # 8) Convert blockquotes: > text → > text (same syntax, just ensure
+        #    no extra escaping happens to the > character)
+        # Slack uses the same > prefix, so this is a no-op for content.
+
+        # 9) Restore placeholders in reverse order
+        for key in reversed(list(placeholders.keys())):
+            text = text.replace(key, placeholders[key])
+
+        return text
+
+    # ----- Reactions -----
+
+    async def _add_reaction(
+        self, channel: str, timestamp: str, emoji: str
+    ) -> bool:
+        """Add an emoji reaction to a message. Returns True on success."""
+        if not self._app:
+            return False
+        try:
+            await self._app.client.reactions_add(
+                channel=channel, timestamp=timestamp, name=emoji
+            )
+            return True
+        except Exception as e:
+            # Don't log as error — may fail if already reacted or missing scope
+            logger.debug("[Slack] reactions.add failed (%s): %s", emoji, e)
+            return False
+
+    async def _remove_reaction(
+        self, channel: str, timestamp: str, emoji: str
+    ) -> bool:
+        """Remove an emoji reaction from a message. Returns True on success."""
+        if not self._app:
+            return False
+        try:
+            await self._app.client.reactions_remove(
+                channel=channel, timestamp=timestamp, name=emoji
+            )
+            return True
+        except Exception as e:
+            logger.debug("[Slack] reactions.remove failed (%s): %s", emoji, e)
+            return False
+
+    # ----- User identity resolution -----
+
+    async def _resolve_user_name(self, user_id: str) -> str:
+        """Resolve a Slack user ID to a display name, with caching."""
+        if not user_id:
+            return ""
+        if user_id in self._user_name_cache:
+            return self._user_name_cache[user_id]
+
+        if not self._app:
+            return user_id
+
+        try:
+            result = await self._app.client.users_info(user=user_id)
+            user = result.get("user", {})
+            # Prefer display_name → real_name → user_id
+            profile = user.get("profile", {})
+            name = (
+                profile.get("display_name")
+                or profile.get("real_name")
+                or user.get("real_name")
+                or user.get("name")
+                or user_id
+            )
+            self._user_name_cache[user_id] = name
+            return name
+        except Exception as e:
+            logger.debug("[Slack] users.info failed for %s: %s", user_id, e)
+            self._user_name_cache[user_id] = user_id
+            return user_id
+
+    async def send_image_file(
+        self,
+        chat_id: str,
+        image_path: str,
+        caption: Optional[str] = None,
+        reply_to: Optional[str] = None,
+        metadata: Optional[Dict[str, Any]] = None,
+    ) -> SendResult:
+        """Send a local image file to Slack by uploading it."""
+        try:
+            return await self._upload_file(chat_id, image_path, caption, reply_to, metadata)
+        except FileNotFoundError:
+            return SendResult(success=False, error=f"Image file not found: {image_path}")
+        except Exception as e:  # pragma: no cover - defensive logging
+            logger.error(
+                "[%s] Failed to send local Slack image %s: %s",
+                self.name,
+                image_path,
+                e,
+                exc_info=True,
+            )
+            text = f"🖼️ Image: {image_path}"
+            if caption:
+                text = f"{caption}\n{text}"
+            return await self.send(chat_id, text, reply_to=reply_to, metadata=metadata)
+
+    async def send_image(
+        self,
+        chat_id: str,
+        image_url: str,
+        caption: Optional[str] = None,
+        reply_to: Optional[str] = None,
+        metadata: Optional[Dict[str, Any]] = None,
+    ) -> SendResult:
+        """Send an image to Slack by uploading the URL as a file."""
+        if not self._app:
+            return SendResult(success=False, error="Not connected")
+
+        try:
+            import httpx
+
+            # Download the image first
+            async with httpx.AsyncClient(timeout=30.0, follow_redirects=True) as client:
+                response = await client.get(image_url)
+                response.raise_for_status()
+
+            result = await self._app.client.files_upload_v2(
+                channel=chat_id,
+                content=response.content,
+                filename="image.png",
+                initial_comment=caption or "",
+                thread_ts=self._resolve_thread_ts(reply_to, metadata),
+            )
+
+            return SendResult(success=True, raw_response=result)
+
+        except Exception as e:  # pragma: no cover - defensive logging
+            logger.warning(
+                "[Slack] Failed to upload image from URL %s, falling back to text: %s",
+                image_url,
+                e,
+                exc_info=True,
+            )
+            # Fall back to sending the URL as text
+            text = f"{caption}\n{image_url}" if caption else image_url
+            return await self.send(chat_id=chat_id, content=text, reply_to=reply_to)
+
+    async def send_voice(
+        self,
+        chat_id: str,
+        audio_path: str,
+        caption: Optional[str] = None,
+        reply_to: Optional[str] = None,
+        metadata: Optional[Dict[str, Any]] = None,
+        **kwargs,
+    ) -> SendResult:
+        """Send an audio file to Slack."""
+        try:
+            return await self._upload_file(chat_id, audio_path, caption, reply_to, metadata)
+        except FileNotFoundError:
+            return SendResult(success=False, error=f"Audio file not found: {audio_path}")
+        except Exception as e:  # pragma: no cover - defensive logging
+            logger.error(
+                "[Slack] Failed to send audio file %s: %s",
+                audio_path,
+                e,
+                exc_info=True,
+            )
+            return SendResult(success=False, error=str(e))
+
+    async def send_video(
+        self,
+        chat_id: str,
+        video_path: str,
+        caption: Optional[str] = None,
+        reply_to: Optional[str] = None,
+        metadata: Optional[Dict[str, Any]] = None,
+    ) -> SendResult:
+        """Send a video file to Slack."""
+        if not self._app:
+            return SendResult(success=False, error="Not connected")
+
+        if not os.path.exists(video_path):
+            return SendResult(success=False, error=f"Video file not found: {video_path}")
+
+        try:
+            result = await self._app.client.files_upload_v2(
+                channel=chat_id,
+                file=video_path,
+                filename=os.path.basename(video_path),
+                initial_comment=caption or "",
+                thread_ts=self._resolve_thread_ts(reply_to, metadata),
+            )
+            return SendResult(success=True, raw_response=result)
+
+        except Exception as e:  # pragma: no cover - defensive logging
+            logger.error(
+                "[%s] Failed to send video %s: %s",
+                self.name,
+                video_path,
+                e,
+                exc_info=True,
+            )
+            text = f"🎬 Video: {video_path}"
+            if caption:
+                text = f"{caption}\n{text}"
+            return await self.send(chat_id, text, reply_to=reply_to, metadata=metadata)
+
+    async def send_document(
+        self,
+        chat_id: str,
+        file_path: str,
+        caption: Optional[str] = None,
+        file_name: Optional[str] = None,
+        reply_to: Optional[str] = None,
+        metadata: Optional[Dict[str, Any]] = None,
+    ) -> SendResult:
+        """Send a document/file attachment to Slack."""
+        if not self._app:
+            return SendResult(success=False, error="Not connected")
+
+        if not os.path.exists(file_path):
+            return SendResult(success=False, error=f"File not found: {file_path}")
+
+        display_name = file_name or os.path.basename(file_path)
+
+        try:
+            result = await self._app.client.files_upload_v2(
+                channel=chat_id,
+                file=file_path,
+                filename=display_name,
+                initial_comment=caption or "",
+                thread_ts=self._resolve_thread_ts(reply_to, metadata),
+            )
+            return SendResult(success=True, raw_response=result)
+
+        except Exception as e:  # pragma: no cover - defensive logging
+            logger.error(
+                "[%s] Failed to send document %s: %s",
+                self.name,
+                file_path,
+                e,
+                exc_info=True,
+            )
+            text = f"📎 File: {file_path}"
+            if caption:
+                text = f"{caption}\n{text}"
+            return await self.send(chat_id, text, reply_to=reply_to, metadata=metadata)
+
+    async def get_chat_info(self, chat_id: str) -> Dict[str, Any]:
+        """Get information about a Slack channel."""
+        if not self._app:
+            return {"name": chat_id, "type": "unknown"}
+
+        try:
+            result = await self._app.client.conversations_info(channel=chat_id)
+            channel = result.get("channel", {})
+            is_dm = channel.get("is_im", False)
+            return {
+                "name": channel.get("name", chat_id),
+                "type": "dm" if is_dm else "group",
+            }
+        except Exception as e:  # pragma: no cover - defensive logging
+            logger.error(
+                "[Slack] Failed to fetch chat info for %s: %s",
+                chat_id,
+                e,
+                exc_info=True,
+            )
+            return {"name": chat_id, "type": "unknown"}
+
+    # ----- Internal handlers -----
+
+    async def _handle_slack_message(self, event: dict) -> None:
+        """Handle an incoming Slack message event."""
+        # Ignore bot messages (including our own)
+        if event.get("bot_id") or event.get("subtype") == "bot_message":
+            return
+
+        # Ignore message edits and deletions
+        subtype = event.get("subtype")
+        if subtype in ("message_changed", "message_deleted"):
+            return
+
+        text = event.get("text", "")
+        user_id = event.get("user", "")
+        channel_id = event.get("channel", "")
+        ts = event.get("ts", "")
+
+        # Determine if this is a DM or channel message
+        channel_type = event.get("channel_type", "")
+        is_dm = channel_type == "im"
+
+        # Build thread_ts for session keying.
+        # In channels: fall back to ts so each top-level @mention starts a
+        #   new thread/session (the bot always replies in a thread).
+        # In DMs: only use the real thread_ts — top-level DMs should share
+        #   one continuous session, threaded DMs get their own session.
+        if is_dm:
+            thread_ts = event.get("thread_ts")  # None for top-level DMs
+        else:
+            thread_ts = event.get("thread_ts") or ts  # ts fallback for channels
+
+        # In channels, only respond if bot is mentioned
+        if not is_dm and self._bot_user_id:
+            if f"<@{self._bot_user_id}>" not in text:
+                return
+            # Strip the bot mention from the text
+            text = text.replace(f"<@{self._bot_user_id}>", "").strip()
+
+        # Determine message type
+        msg_type = MessageType.TEXT
+        if text.startswith("/"):
+            msg_type = MessageType.COMMAND
+
+        # Handle file attachments
+        media_urls = []
+        media_types = []
+        files = event.get("files", [])
+        for f in files:
+            mimetype = f.get("mimetype", "unknown")
+            url = f.get("url_private_download") or f.get("url_private", "")
+            if mimetype.startswith("image/") and url:
+                try:
+                    ext = "." + mimetype.split("/")[-1].split(";")[0]
+                    if ext not in (".jpg", ".jpeg", ".png", ".gif", ".webp"):
+                        ext = ".jpg"
+                    # Slack private URLs require the bot token as auth header
+                    cached = await self._download_slack_file(url, ext)
+                    media_urls.append(cached)
+                    media_types.append(mimetype)
+                    msg_type = MessageType.PHOTO
+                except Exception as e:  # pragma: no cover - defensive logging
+                    logger.warning("[Slack] Failed to cache image from %s: %s", url, e, exc_info=True)
+            elif mimetype.startswith("audio/") and url:
+                try:
+                    ext = "." + mimetype.split("/")[-1].split(";")[0]
+                    if ext not in (".ogg", ".mp3", ".wav", ".webm", ".m4a"):
+                        ext = ".ogg"
+                    cached = await self._download_slack_file(url, ext, audio=True)
+                    media_urls.append(cached)
+                    media_types.append(mimetype)
+                    msg_type = MessageType.VOICE
+                except Exception as e:  # pragma: no cover - defensive logging
+                    logger.warning("[Slack] Failed to cache audio from %s: %s", url, e, exc_info=True)
+            elif url:
+                # Try to handle as a document attachment
+                try:
+                    original_filename = f.get("name", "")
+                    ext = ""
+                    if original_filename:
+                        _, ext = os.path.splitext(original_filename)
+                        ext = ext.lower()
+
+                    # Fallback: reverse-lookup from MIME type
+                    if not ext and mimetype:
+                        mime_to_ext = {v: k for k, v in SUPPORTED_DOCUMENT_TYPES.items()}
+                        ext = mime_to_ext.get(mimetype, "")
+
+                    if ext not in SUPPORTED_DOCUMENT_TYPES:
+                        continue  # Skip unsupported file types silently
+
+                    # Check file size (Slack limit: 20 MB for bots)
+                    file_size = f.get("size", 0)
+                    MAX_DOC_BYTES = 20 * 1024 * 1024
+                    if not file_size or file_size > MAX_DOC_BYTES:
+                        logger.warning("[Slack] Document too large or unknown size: %s", file_size)
+                        continue
+
+                    # Download and cache
+                    raw_bytes = await self._download_slack_file_bytes(url)
+                    cached_path = cache_document_from_bytes(
+                        raw_bytes, original_filename or f"document{ext}"
+                    )
+                    doc_mime = SUPPORTED_DOCUMENT_TYPES[ext]
+                    media_urls.append(cached_path)
+                    media_types.append(doc_mime)
+                    msg_type = MessageType.DOCUMENT
+                    logger.debug("[Slack] Cached user document: %s", cached_path)
+
+                    # Inject text content for .txt/.md files (capped at 100 KB)
+                    MAX_TEXT_INJECT_BYTES = 100 * 1024
+                    if ext in (".md", ".txt") and len(raw_bytes) <= MAX_TEXT_INJECT_BYTES:
+                        try:
+                            text_content = raw_bytes.decode("utf-8")
+                            display_name = original_filename or f"document{ext}"
+                            display_name = re.sub(r'[^\w.\- ]', '_', display_name)
+                            injection = f"[Content of {display_name}]:\n{text_content}"
+                            if text:
+                                text = f"{injection}\n\n{text}"
+                            else:
+                                text = injection
+                        except UnicodeDecodeError:
+                            pass  # Binary content, skip injection
+
+                except Exception as e:  # pragma: no cover - defensive logging
+                    logger.warning("[Slack] Failed to cache document from %s: %s", url, e, exc_info=True)
+
+        # Resolve user display name (cached after first lookup)
+        user_name = await self._resolve_user_name(user_id)
+
+        # Build source
+        source = self.build_source(
+            chat_id=channel_id,
+            chat_name=channel_id,  # Will be resolved later if needed
+            chat_type="dm" if is_dm else "group",
+            user_id=user_id,
+            user_name=user_name,
+            thread_id=thread_ts,
+        )
+
+        msg_event = MessageEvent(
+            text=text,
+            message_type=msg_type,
+            source=source,
+            raw_message=event,
+            message_id=ts,
+            media_urls=media_urls,
+            media_types=media_types,
+            reply_to_message_id=thread_ts if thread_ts != ts else None,
+        )
+
+        # Add 👀 reaction to acknowledge receipt
+        await self._add_reaction(channel_id, ts, "eyes")
+
+        await self.handle_message(msg_event)
+
+        # Replace 👀 with ✅ when done
+        await self._remove_reaction(channel_id, ts, "eyes")
+        await self._add_reaction(channel_id, ts, "white_check_mark")
+
+    async def _handle_slash_command(self, command: dict) -> None:
+        """Handle /hermes slash command."""
+        text = command.get("text", "").strip()
+        user_id = command.get("user_id", "")
+        channel_id = command.get("channel_id", "")
+
+        # Map subcommands to gateway commands — derived from central registry.
+        # Also keep "compact" as a Slack-specific alias for /compress.
+        from hermes_cli.commands import slack_subcommand_map
+        subcommand_map = slack_subcommand_map()
+        subcommand_map["compact"] = "/compress"
+        first_word = text.split()[0] if text else ""
+        if first_word in subcommand_map:
+            # Preserve arguments after the subcommand
+            rest = text[len(first_word):].strip()
+            text = f"{subcommand_map[first_word]} {rest}".strip() if rest else subcommand_map[first_word]
+        elif text:
+            pass  # Treat as a regular question
+        else:
+            text = "/help"
+
+        source = self.build_source(
+            chat_id=channel_id,
+            chat_type="dm",  # Slash commands are always in DM-like context
+            user_id=user_id,
+        )
+
+        event = MessageEvent(
+            text=text,
+            message_type=MessageType.COMMAND if text.startswith("/") else MessageType.TEXT,
+            source=source,
+            raw_message=command,
+        )
+
+        await self.handle_message(event)
+
+    async def _download_slack_file(self, url: str, ext: str, audio: bool = False) -> str:
+        """Download a Slack file using the bot token for auth."""
+        import httpx
+
+        bot_token = self.config.token
+        async with httpx.AsyncClient(timeout=30.0, follow_redirects=True) as client:
+            response = await client.get(
+                url,
+                headers={"Authorization": f"Bearer {bot_token}"},
+            )
+            response.raise_for_status()
+
+        if audio:
+            from gateway.platforms.base import cache_audio_from_bytes
+            return cache_audio_from_bytes(response.content, ext)
+        else:
+            from gateway.platforms.base import cache_image_from_bytes
+            return cache_image_from_bytes(response.content, ext)
+
+    async def _download_slack_file_bytes(self, url: str) -> bytes:
+        """Download a Slack file and return raw bytes."""
+        import httpx
+
+        bot_token = self.config.token
+        async with httpx.AsyncClient(timeout=30.0, follow_redirects=True) as client:
+            response = await client.get(
+                url,
+                headers={"Authorization": f"Bearer {bot_token}"},
+            )
+            response.raise_for_status()
+        return response.content