A system is disclosed. A system according to an embodiment may comprise a network interface, at least one processor, and at least one memory. The at least one memory may store instructions that, when executed, cause the at least one processor to: receive a first request for calling a first chatbot in connection with chatting based on text and/or speech through the network interface; request the first chatbot to join the chatting; receive a second request for calling a second chatbot in connection with the chatting through the network interface; request the second chatbot to join the chatting; receive a third request comprising a task related to the first chatbot and unrelated to the second chatbot; provide the third request to the first chatbot and the second chatbot after the first chatbot and the second chatbot join the chatting; receive a first response related to the task from the first chatbot; receive a second response indicating failure of the task or inability regarding the task from the second chatbot; and provide only the first response through the network interface. Additional various embodiments identified through the specification are possible.