Writing Events

Events are appended to a named array field on an existing object -- e.g. a READING field on AAA.PYTHON-EXAMPLE, addressed as AAA.PYTHON-EXAMPLE:READING.

info

Unlike object/data writes, the event service's write endpoint expects a small table (the same shape as pandas.DataFrame.to_json(orient="split")), not a single event's JSON directly. odsl.types.events_dataframe() builds that for you from one or more Event builders, whether you're writing a single event or a batch.

Writing events

from odsl import sdk, types

odsl = sdk.ODSL()
odsl.setStage('dev')
odsl.loginWithSecret(tenant_id, client_id, secret)

event_key = 'AAA.PYTHON-EXAMPLE:READING'
events = [
    types.Event(event_key, 'READING-1', '2026-08-20T00:00:00Z').set_property('value', 41.2),
    types.Event(event_key, 'READING-2', '2026-08-20T00:15:00Z').set_property('value', 42.8),
]
odsl.update('event', 'private', types.events_dataframe(events))

Reading events back

# Reading a key back returns every event under it
readings = odsl.get('event', 'private', event_key)

Addressing events

event must be in OBJECTID:EVENTID form -- exactly one colon, splitting into the id of an existing private object and a field name. Writing an event actually appends it to an array field (named by the EVENTID half) on that object; OBJECTID:EVENTID is also the key you get()/filter by when reading events back. This is unrelated to eventid (the second constructor argument), which is just that specific event's own unique id within the array.

Custom properties on an event are flat top-level keys (set via set_property), not nested under a properties key -- this is what you're filtering on with queries like:

odsl.list('event', 'public', {'_filter': '{"MID_PRICE": {"$gt": 50}}'})

The reserved top-level keys the server treats specially -- avoid these as custom property names -- are: eventid, eventtype, event, eventlist, eventtime, eventstart, eventend, timezone, and status.

note

Event always sets eventtype to '#Event' by default (call set_eventtype to override it). The server reads eventtype unconditionally when parsing a write, so a payload without it fails with [5005] Update Error: Document does not contain key eventtype instead of falling back to a default, despite what its own docs suggest -- the SDK works around this for you, but it's worth knowing about if you're building the payload by hand instead.

See full-example.py for this in the context of a full object/curve/time-series/event walkthrough, and the Event/events_dataframe docstrings in odsl/types.py for further detail.