adverb, noun which may take the genitive case particle 'no'
as promised; just as one promised
Used to describe an action or state that matches a previous promise. Often appears with verbs like 来る, する, なる, or as a の-adjective modifying a noun.
彼は約束通り、時間通りに来た。
He came on time, just as he promised.
約束通りの品物が届
The item arrived exactly as promised.