Schedules a saved page or theme version to go live at publishAt. For page drafts, versionId is the id returned by the draft save. The scheduler publishes the stored content when the time comes.

Rules

• publishAt must be in the future (400).
• One schedule per slot: a page can have at most one scheduled version, and a project at most one scheduled theme version. If the slot is taken, the response is 409 CONFLICT and nothing changes.
• A page draft can be scheduled only while it is still the page's draft head and was built on the current live page revision. A history version whose recorded page revision no longer matches live is 409 STALE_PAGE.
• At fire time the base is checked again. If live content moved after scheduling, the publication is cancelled instead of overwriting the newer edit (a draft returns to ACTIVE).

Replacing a page schedule. Set replaceScheduledVersionId to swap the page's current scheduled version for this one in a single transaction. The replaced version is closed (a draft returns to ACTIVE, a history version becomes CANCELLED). If it is no longer the page's scheduled version, the response is 409 CONFLICT. Two versions of different pages are 400 INVALID_PARAMS, and a version cannot replace itself. Retrying an identical replacement that already committed returns the scheduled row. For type: "theme" the field is refused with 400: no atomic theme replacement exists, so cancel the scheduled theme version first.

Manage the result with PATCH /versions/{versionId} (reschedule), PUT /versions/{versionId} (replace content), DELETE /versions/{versionId} (cancel) or POST /versions/{versionId}/publish-now.

Required scope: content:publish