# X_SYNC_UNCONFIGURED

## Means

a live hook needed the page socket and no sync target was configured

## Typical cause

a live `useQuery` (or anything else that needs the page's one socket) ran, and neither `installRealtime({ sync })` nor the document's `<meta name="ultimate-sync">` named a target. `x dev` and the container render that meta on every document; a page served some other way does not

## Fix

serve the page through `x dev` or the container, which render `<meta name="ultimate-sync">` (and `SYNC_URL` where the socket is not on the page origin). Or pass `installRealtime({ signal: createSignal, sync: { url, buildId } })` from `@ultimat3/realtime`

[Realtime](/error-codes#realtime)