At-Most-Once Publishing

Plain English first

The hard case is not the request that fails. It is the request that you never got an answer to. The bot sent the bytes, the connection died, and now nobody knows whether the post exists. Almost every naive system retries here, and that is how an account posts the same thing three times.

The rule this skill enforces: an unknown outcome stays unknown. It is reconciled by going and LOOKING at the platform, exactly once, and it is never automatically resent. You choose at-most-once over at-least-once, because a missing post is recoverable by a human and a duplicate post is not.

Two rows, not one

Almost every broken version of this collapses two different things into one row, and then cannot express a retry without either blocking it or losing identity. Keep them separate: