To obtain data on the status of history retranslation, use the command retranslator/get_stats:

svc=retranslator/get_stats&params={"itemId":<long>}

Parameter “au” - the number of objects, which have been added/deleted to/from retranslator directly.

{
"au": <long>, /* the number of objects in the retranslator */
"ru": <long>, /* the number of objects in the queue for history retranslation */
"hf": <long>, /* time 'from' */
"ht": <long>  /* time 'to' */
"hc": <uint>, /* current retranlation messages time */
"hms": <uint>, /* current queue of historical messages */
"hp": <uint>, /* progress percent */
}