---
title: "What is an event in LUSID?"
slug: "what-is-an-event-in-lusid"
tags: ["instrument event"]
updated: 2024-09-18T16:02:13Z
published: 2024-09-18T16:02:13Z
canonical: "support.lusid.com/what-is-an-event-in-lusid"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://support.lusid.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What is an event in LUSID?

An *event* in LUSID can refer to either a system event or to an instrument event (these are not the same).

## System events

LUSID emits a *system event* when an internal operation completes. This can be within LUSID itself, or in one of its [ecosystem applications](/v1/docs/understanding-all-the-applications-in-the-finbourne-platform) such as Drive, Scheduler or Luminesce.

For example, when you call the `CreatePortfolio` API (either directly, or via an SDK, Luminesce, the LUSID web app or any other proxy), LUSID emits a `PortfolioCreated` system event providing the operation succeeds.

To see a list of all possible system events, call the Notification Service `ListEventTypes` API. [More information](/v1/docs/what-system-events-can-i-subscribe-to).

System events are designed to be handled by the:

- [Notification Service](/v1/docs/introduction-to-the-notification-service), so for example you can handle the `PortfolioCreated` event to send an email to a portfolio manager.
- [Workflow Service](/v1/docs/introduction-to-the-workflow-service), so for example you can handle the `PortfolioCreated` event to trigger a task to load transactions.

## Instrument events

There are two types of *instrument event*, both emitted by LUSID in response to real-world events impacting the instruments you hold.

### Instrument lifecycle events

LUSID emits an *instrument lifecycle event* when an instrument mastered in LUSID reaches a milestone. This occurs automatically; there is no user input.

For example, LUSID emits a `BondCouponEvent` every time a coupon is due on an instrument of type `Bond`. You can handle this event to capture the coupon amount and perform an operation such as adding it to the cash balance in every portfolio with a holding in that bond.

[More information](/v1/docs/understanding-instrument-lifecycle-events-emitted-by-lusid).

### Corporate action events

LUSID emits a *corporate action event* on the ex-dividend date of a corporate action manually loaded into a LUSID corporate action source.

For example, LUSID emits a `CashDividendEvent` on the ex-dividend date of a cash dividend for an equity, providing you have loaded that cash dividend into a corporate action source. You can handle this event to capture the dividend amount and perform an operation such as adding it to a cash balance in every portfolio that both subscribes to the corporate action source *and* has a holding in the equity.

Note it is possible for a corporate action event to override a lifecycle event for the same underlying instrument.

[More information](/v1/docs/understanding-dedicated-corporate-action-events).