The README explicitly requires authentication, with credentials supplied via EIGHTCTL_EMAIL, EIGHTCTL_PASSWORD, or the local config file ~/.config/eightctl/config.yaml; these are sensitive account credentials and carry typical risks of local leakage, log exposure, or accidental commit.

By design, the tool needs to connect to Eight Sleep-related services to query status and send control commands such as temperature, alarms, and schedules. The materials do not list specific remote hosts, but they state the API is unofficial and rate-limited, indicating network communication with the device/service provider side.

System checks mark it as prompt-only, and the materials do not describe arbitrary local code execution, spawning extra processes, or requesting elevated system privileges; based on the available information, it does not appear to have execution capabilities beyond the stated skill behavior.

It is known to read the local config file ~/.config/eightctl/config.yaml and handle account information plus device status, alarms, and schedules; there is no indication of access to unrelated directories or broad file operations, so current exposure appears limited to functionally relevant data.

The source is an open-source GitHub repository, and system checks mark it as open-source, with extremely high community adoption (about 377k stars), which are strong positive signals. The license and maintenance status are unclear, and the API is unofficial, so maintainability should be watched, but the current materials do not justify a high-risk rating.