line_item_update
Edit a line item. Any real change returns it to draft, and only it.
Updates a Line Item. Omit a field to leave it alone; send null to clear it.
Input
Takes campaign_plan_name, line_item_id and base_revision, plus any field line_item_create accepts. countries is replaced wholesale — send [] to clear the geography.
Warning
Editing cancels a validation — and only this line's
A validated line returns to draft and must be re-validated before it can be
executed again. The plan’s own approval stands: approving is a statement about
the allocation as a whole, and one row moving does not unmake the rest.
Note
Live objects are never altered from here
If the line already created campaigns or ad sets, they are untouched. The divergence simply becomes visible, since the line keeps the record of what it created. Changing what is live is the mutation tools’ job.
Tip
Clearing an end date flips how the budget reads
From a total for a period to a rate per day, without the figure changing. That is allowed — and it returns the line to draft, so the change can never be silent.
Requires the campaign_plan:write scope.