Methods, systems, and apparatus, including computer programs, for managing keys for virtual machines (VM). One method includes receiving a first public key associated with a first user from a first client machine (CM), receiving a second public key associated with a second user from a second CM, and updating metadata associated with a project that includes a first VM and a second VM to include the first and the second public keys. The first public key and a corresponding first private key were generated on the first CM in response to a determination that the first CM lacked a private key for communication with the first VM by the first user. The second public key and a corresponding second private key were generated on the second CM in response to a determination that the second CM lacked a private key for communication with the second VM by the second user.