The Attune Store

The Attune Store provides a timestamped history of saved instrument JSON files.

Saving an instrument

An Instrument can be saved to the Attune Store by using In order to use store, the instrument must have a name.

If transitions have been applied in memory, the whole chain will be stored with a single call.

Retrieving an instrument

An individual Instrument can be retrieved using attune.load(), given its name.


If you wish to select the instrument which was active at some time in the past, you can pass either a datetime object or a date string. If passed as a string, either a timestamp such as an ISO8601 format or certain phrasings of natural language can be passed. In general phrasing as “<X> <units> ago” is likely to yield good results.

Similarly if you want to find the next instrument object from a certain date, you can pass the date as well as set reverse to False to set the search direction to forward.

from dateutil import tz
import datetime
attune.load("instr", datetime.datetime(2022, 7, 15, tz=tz.UTC)) # Load the instrument from midnight UTC on July 15, 2022
attune.load("instr", "3 days ago") # Load using a relative and natural language time
attune.load("instr", "3 days ago", False) # Load the next instrument created after "3 days ago"

Listing available instruments

A list of available instrument histories can be obtained using attune.catalog().


By default, this provides a simple list of string names of instruments.

If you pass the argument full as True, then attune.catalog() will instead return a dictionary of names to loaded Instrument objects.


Instrument history

Since the attune store retains a permanent history, we have methods to interact with that history beyond simply loading


attune.restore() works exactly like attune.load(), except instead of returning the instrument to use immediately, it returns the older instrument to the head (active) so that it will be retrieved with attune.load() without additional arguments. In doing so, it applies a restore transition indicating the time passed in to restore it. Restoring to the currently active instrument is a no-op and so the time argument is required.

attune.restore("instr", "1 week ago")
instr = attune.load("instr")  # Now the same as it was 1 week prior


attune.undo() provides the instrument from prior to the latest transition. If the transitions have occurred in memory (i.e. not stored to the Attune Store) then it simply provides the previous instrument object directly. If instead the Instrument was loaded from the attune store, it retrieves the instrument that was stored just before itself from the attune store.