mcp_slack

Instructions

Implementation Reference

• main.py:97-143 (handler)

  The @mcp.tool() decorator registers the get_user_messages handler function, which fetches Slack user messages from a channel by username, filters them, and formats for output.
  @mcp.tool() async def get_user_messages(channel_id: str, username: str, limit: int = 10) -> str: """ Fetch messages by a specific user (given by name) from a Slack channel. Args: channel_id: The Slack channel ID. username: The Slack username or real name of the user. limit: How many messages to check (optional). """ # Step 1: Get user list users_data = await make_slack_request("users.list") if not users_data or not users_data.get("ok"): return "❌ Failed to fetch user list." # Step 2: Create a user_map and find the user ID user_map = {} user_id = None for user in users_data["members"]: uid = user.get("id") name = user.get("name") real_name = user.get("real_name") user_map[uid] = real_name or name or uid if name == username or real_name == username: user_id = uid if not user_id: return f"❌ No Slack user found with name '{username}'." # Step 3: Fetch channel messages params = {"channel": channel_id, "limit": limit} data = await make_slack_request("conversations.history", params) if not data or not data.get("ok"): return "❌ Unable to fetch messages." # Step 4: Filter messages by user_id user_msgs = [msg for msg in data.get("messages", []) if msg.get("user") == user_id] if not user_msgs: return f"No messages found from user '{username}' in the channel." # ✅ Step 5: Format messages with user_map return "\n---\n".join(format_slack_message(msg, user_map) for msg in user_msgs)
• main.py:34-40 (helper)

  Helper function to format individual Slack messages with timestamp and user name.
  def format_slack_message(msg: dict, user_map: dict[str, str]) -> str: """Format Slack message into a readable string with user name.""" user_id = msg.get("user", "unknown user") user_name = user_map.get(user_id, user_id) # fallback to user ID if name not found text = msg.get("text", "") ts = msg.get("ts", "") return f"[{ts}] {user_name}: {text}"
• main.py:19-33 (helper)

  Helper function to make authenticated requests to the Slack API.
  async def make_slack_request(method: str, params: dict[str, Any] | None = None) -> dict[str, Any] | None: """Make a request to the Slack Web API with proper error handling.""" headers = { "Authorization": f"Bearer {SLACK_TOKEN}", "Content-Type": "application/x-www-form-urlencoded" } async with httpx.AsyncClient() as client: try: response = await client.post(f"{SLACK_API_BASE}/{method}", data=params, headers=headers, timeout=10.0) response.raise_for_status() return response.json() except Exception as e: print(f"Slack API error: {e}") return None
• main.py:99-106 (schema)

  Input schema and description from the function docstring.
  """ Fetch messages by a specific user (given by name) from a Slack channel. Args: channel_id: The Slack channel ID. username: The Slack username or real name of the user. limit: How many messages to check (optional). """