Cancel a scheduled post

Cancels a post that is still waiting to publish. The post moves to ARCHIVED and the publishing pipeline drops it. Drafts can be cancelled the same way; posts that have already gone out cannot.

Use case: a client pulls a campaign at the last minute. Your calendar shows a scheduled post, the client changes their mind, and you cancel it from your own UI. Take the post's id straight from the brand's post list and call this endpoint; the row moves to ARCHIVED and drops out of a {"status":["SCHEDULED"]} filter on the next read.

Use case: cleaning up before disconnecting a channel. Disconnecting a connection does not cancel the posts already queued to it — they fail at publish time with SY95045 instead. Cancel the scheduled posts first, then disconnect, and the customer sees no failures at all.

Notes.

• The request body must be wrapped in an input object.
• Check success, not the HTTP status. A post that already published, or that was already cancelled, returns HTTP 200 with success: false.
• This is not a delete. Nothing is removed from any platform. A post that has already published stays live, and this call simply reports success: false for it. There is no endpoint that unpublishes a social post; removing it is done on the platform itself.
• Cancellation is all-or-nothing across the post's channels. There is no way to cancel a scheduled post on one platform while letting it publish on another; create separate posts if you need that.
• The post is still readable afterwards with GET /social/posts/{postId}, with post.status of ARCHIVED.

Write operation: not executed against the live account. The request and response shown are built from the API schema.