This study explores the potential of chatbots in promoting sustainable travel practices among tourists, particularly in the context of the Gili Islands, Indonesia. The research employs an exploratory qualitative approach, combining semi-structured interviews, focus group discussions, and field observations to develop a theoretical model for the chatbot's design and its potential impact. The study aims to conceptualize a chatbot that facilitates pro-environmental behavior spillover (PEB) among tourists, encouraging them to continue sustainable practices after their trip. The chatbot will send messages via WhatsApp to tourists, reflecting on their sustainable travel experiences and providing educational information about the positive environmental impact of their actions. The research identifies development requirements, including governance and investment, and discusses the potential immediate and spillover effects on the government, businesses, and education. The findings suggest that the chatbot can enhance the Gili Islands' branding as an environmentally friendly destination, improve public awareness of sustainability, and foster an ecosystem of pro-sustainable businesses. The study also highlights the importance of personalized and engaging content to maintain user engagement and the need for collaboration between various stakeholders to ensure the chatbot's success.This study explores the potential of chatbots in promoting sustainable travel practices among tourists, particularly in the context of the Gili Islands, Indonesia. The research employs an exploratory qualitative approach, combining semi-structured interviews, focus group discussions, and field observations to develop a theoretical model for the chatbot's design and its potential impact. The study aims to conceptualize a chatbot that facilitates pro-environmental behavior spillover (PEB) among tourists, encouraging them to continue sustainable practices after their trip. The chatbot will send messages via WhatsApp to tourists, reflecting on their sustainable travel experiences and providing educational information about the positive environmental impact of their actions. The research identifies development requirements, including governance and investment, and discusses the potential immediate and spillover effects on the government, businesses, and education. The findings suggest that the chatbot can enhance the Gili Islands' branding as an environmentally friendly destination, improve public awareness of sustainability, and foster an ecosystem of pro-sustainable businesses. The study also highlights the importance of personalized and engaging content to maintain user engagement and the need for collaboration between various stakeholders to ensure the chatbot's success.