Offline playback

How screens keep playing through network and server outages.

Screens are built to keep going when the network doesn't. Once a screen has synced, it needs no connection at all to keep playing.

How it works

1. When you publish, the screen receives a manifest: the playlists, slides, schedule rules and a list of media files with their checksums.
2. The agent downloads every media file into a local cache and verifies its sha256 checksum.
3. Only when everything is downloaded and verified does the player switch to the new version.
4. The player plays entirely from the local cache, served by the agent on the screen itself.

If the network drops halfway through a download, the screen keeps playing the previous version and resumes later.

What works offline

What you'll see in the editor

An offline screen shows as Offline in the editor with the time it was last seen. It's still playing; it just can't tell you. When it comes back it reports in, fetches anything new and catches up.

Restarts and power cuts

The cache and the last good manifest survive restarts. A screen that loses power and boots without a network goes straight back to playing its cached content.

Cache size

The cache holds the media the current version needs; files that are no longer used are removed after each sync. The cache is capped at 8 GB by default — if the current content alone is bigger, the least recently used files are evicted, so keep the limit comfortably above the size of everything a screen plays. Change it with CACHE_MAX_MB — see installing the agent.