Gatherings MCP Server

Instructions

Implementation Reference

• src/index.ts:362-367 (handler)

  MCP tool handler for 'remove_member': validates input arguments and appends the corresponding CLI command to be executed via child_process.execAsync.

  case 'remove_member':
    if (!isMemberArgs(args)) {
      throw new McpError(ErrorCode.InvalidParams, 'Invalid remove_member arguments');
    }
    command += ` remove-member "${args.gathering_id}" "${args.member_name}"`;
    break;

• src/index.ts:235-252 (schema)

  Input schema and registration of the 'remove_member' tool in the MCP ListTools response.

  {
    name: 'remove_member',
    description: 'Remove a member from a gathering',
    inputSchema: {
      type: 'object',
      properties: {
        gathering_id: {
          type: 'string',
          description: 'ID of the gathering',
        },
        member_name: {
          type: 'string',
          description: 'Name of the member to remove',
        },
      },
      required: ['gathering_id', 'member_name'],
    },
  },

• gatherings.py:440-440 (registration)

  Registers the handle_remove_member function for the 'remove-member' CLI subcommand in the handlers dictionary.

  "remove-member": handle_remove_member

• gatherings.py:392-416 (handler)

  CLI handler for 'remove-member': invokes service.remove_member and formats success/error output in JSON or human-readable format.

  def handle_remove_member(service, args):
      """Handle the remove-member command."""
      try:
          gathering = service.remove_member(args.gathering_id, args.member_name)
          result = {
              "success": True,
              "removed": {
                  "member_name": args.member_name,
                  "gathering_id": gathering.id,
                  "total_members": gathering.total_members
              }
          }
          if args.json:
              print(json.dumps(result))
          else:
              print(f"Removed member '{args.member_name}' from gathering '{gathering.id}'")
              print(f"Total members: {gathering.total_members}")
          return True
      except ValueError as e:
          error = {"success": False, "error": str(e)}
          if args.json:
              print(json.dumps(error))
          else:
              print(f"Error: {e}")
          return False

• models.py:258-308 (handler)

  Core database implementation: validates gathering open status, member existence, no expenses/payments, then deletes member and decrements total_members.

  def remove_member(self, gathering_id: str, member_name: str) -> None:
      """
      Remove a member from a gathering.
      
      Args:
          gathering_id: The ID of the gathering
          member_name: The name of the member
          
      Raises:
          ValueError: If the gathering is closed, the member doesn't exist, 
                      or the member has expenses/payments
      """
      session = self.Session()
      try:
          # Get the gathering
          gathering = session.query(Gathering).filter_by(id=gathering_id).first()
          if not gathering:
              raise ValueError(f"Gathering '{gathering_id}' not found")
          
          # Check if gathering is open
          if gathering.status == GatheringStatus.CLOSED:
              raise ValueError(f"Cannot remove member from closed gathering '{gathering_id}'")
          
          # Get the member to remove
          member = session.query(Member).filter_by(gathering_id=gathering_id, name=member_name).first()
          if not member:
              raise ValueError(f"Member '{member_name}' not found in gathering '{gathering_id}'")
          
          # Check if member has expenses
          expenses_count = session.query(Expense).filter_by(member_id=member.id).count()
          if expenses_count > 0:
              raise ValueError(f"Cannot remove member '{member_name}' who has recorded expenses")
          
          # Check if member has payments
          payments_count = session.query(Payment).filter_by(member_id=member.id).count()
          if payments_count > 0:
              raise ValueError(f"Cannot remove member '{member_name}' who has recorded payments")
          
          # Delete the member
          session.delete(member)
          
          # Update the total members count
          gathering.total_members -= 1
          
          session.commit()
          
      except Exception as e:
          session.rollback()
          raise e
      finally:
          session.close()