The inhabitants of Cuba's capital, Havana, are using semipublic group chats on messaging applications such as WhatsApp and Telegram to access food, hygiene products, medication, and other basic necessities during times of scarcity. This has been especially prevalent during the COVID-19 pandemic. Such chat groups created digital spaces in which locals swap scarce goods and share vital information about the availability of products in the government-run shops, creative entrepreneurs offer online delivery services, and black-market vendors sell commodities that are in short supply. We examine the conflicting value systems that shape the interactions on these messaging apps, where solidarity and sharing as well as market-mediated exchanges come to coexist and must be negotiated on an everyday basis. The article is accompanied by a series of "screen walks"-that is, short mobile phone videos, in which research participants explain the dynamics of the groups they participate in. [barter, Cuba, informal economy, moral economies, social media] R e s u m e n Los habitantes de La Habana, la capital de Cuba, utilizan chats grupales semipúblicos en aplicaciones de mensajería como WhatsApp y Telegram para acceder a alimentos, productos de higiene, medicamentos y otros productos de primera necesidad en épocas de escasez y, en particular, durante la pandemia de COVID-19. Estos grupos de chat