Slack MCP Server

Instructions

Implementation Reference

• slack_mcp/server.py:506-522 (handler)

  MCP tool handler function that parses comma-separated users, creates SlackClient instance, calls the underlying invite_to_channel method, and returns JSON result or error.

  @mcp.tool()
  async def invite_to_channel(channel: str, users: str) -> str:
      """
      Invite users to a Slack channel.
  
      Args:
          channel: Channel ID
          users: Comma-separated list of user IDs
      """
      try:
          client = SlackClient()
          users_list = users.split(",")
          result = await client.invite_to_channel(channel, users_list)
          return json.dumps(result, indent=2)
      except Exception as e:
          return json.dumps({"error": str(e)}, indent=2)

• slack_mcp/server.py:206-210 (helper)

  Helper method in SlackClient class that makes the actual Slack API POST request to conversations.invite endpoint with channel and comma-joined user IDs.

  async def invite_to_channel(self, channel: str, users: List[str]) -> Dict[str, Any]:
      """Invite users to a channel."""
      data = {"channel": channel, "users": ",".join(users)}
      return await self._make_request("POST", "conversations.invite", json_data=data)

• slack_mcp/server.py:506-506 (registration)

  Registration of the invite_to_channel tool using the @mcp.tool() decorator.

  @mcp.tool()