mcp_slack

Instructions

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).

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).
  """