Limits

Posato adds deliberate friction; it is not a lock you cannot open.

It does not resist a device administrator and can always be removed. Ending a session early is always possible.
On macOS, blocking works only while Posato is running. Closing its window keeps it running in the menu bar, and after the one-time setup Posato opens quietly at login. If Posato quits, or after sleep, wake, or a network change, a pause you started yourself stops blocking until you resume it in Posato. Without the setup, starting or resuming needs administrator approval each time. A session received from your iPhone blocks on the Mac only after you resume it there; without the setup, that also needs administrator approval.
On macOS, schedules start only on a Mac that finished the setup and only while Posato is running. If Posato opens, including at login, or the Mac wakes during a scheduled pause, the pause starts again on its own, usually within a minute, and still ends at its planned time; no password is asked. Quitting Posato stops new scheduled starts until it opens again; closing the window does not.
On macOS, paused apps are quit while a session is active, including apps that were already open when it started, so unsaved work in them can be lost.
On macOS, website blocking covers Safari and Google Chrome Stable for web traffic on ports 80 and 443 while they use the system proxy settings. Firefox, other browsers, in-app browsers, and apps that bypass the system proxy are not covered. Visiting a paused site by its IP address is not blocked, and iCloud Private Relay can bypass blocking without being detected. A session does not start blocking while a VPN or a manually configured proxy is active. Connections to servers on the Mac itself (localhost, 127.0.0.1, and ::1) keep working during a session. Pages already loaded, cached, or downloaded are not erased, and the pause page may occasionally not appear even though the site stays blocked.
On macOS, Posato uses a background helper that requires administrator approval and may ask for Automation permission to show its pause page in the current tab.
On iPhone, the system clears restrictions after a session ends and may keep them for a while past the end time. Restrictions from sessions shorter than 15 minutes clear only when Posato is open at the end or when you open it again.
On iPhone, if Safari was already open, the first page it opens after a pause that blocks websites ends may stay blank. This appears to be how iOS behaves when the restriction is lifted, and Posato cannot avoid it. The next page you open loads.
Schedule times follow each device's own clock. A schedule is at least 15 minutes long, and on iPhone it needs Screen Time access.
A device on an earlier version of Posato stops syncing once another device runs Posato 1.3. Update Posato on every device to keep them in sync.
Sync is best effort. Posato cannot promise when, or whether, a change reaches your other device, and it cannot wake a sleeping device.
If every copy of the workspace key is lost, synchronized data cannot be recovered. Data already copied to another device cannot be erased remotely.

Posato targets macOS 13 or later on Apple silicon and Intel Macs, and iOS 18 or later; see the platform matrix for what was checked on each. See the privacy policy for what Posato keeps on your devices and in iCloud.