The recorded steps of a repo's history, spoken plural — each one a promise written down; they ride KP1's word alone.
Latin committere (to join, entrust, send together), from com- (together) + mittere (to send); the recorded steps a thing was sent forward into being, each one a small promise fixed in place.
The recorded steps of a history, each one a small commitment fixed in place. Every one rests on a single held authority, which is what makes it a promise rather than a draft.