---
title: "Using LUSID filtering syntax to subscribe to events conditionally"
slug: "using-lusid-filtering-syntax-to-subscribe-to-events-conditionally"
updated: 2025-04-16T14:18:49Z
published: 2025-04-16T14:18:49Z
canonical: "support.lusid.com/using-lusid-filtering-syntax-to-subscribe-to-events-conditionally"
---

> ## 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.

# Using LUSID filtering syntax to subscribe to events conditionally

You can use LUSID's [filtering syntax](/v1/docs/filtering-information-retrieved-from-lusid) to subscribe to an event conditionally; that is, to only trigger notifications when those conditions are met.

You can filter on any of the [attributes](/v1/docs/what-system-events-can-i-subscribe-to) of an event. For example, when you call the [ListEventTypes](https://www.lusid.com/docs/api/notification/endpoints/event-types/ListEventTypes) API to examine the `PortfolioCreated` event, you see it has seven common string attributes in the `headerSchema` and two specific string attributes in the `bodySchema`:

```json
{
  "values": [
    {
      "id": "PortfolioCreated",
      "displayName": "Portfolio Created",
      "description": "An event of this type is fired whenever a PortfolioCreated event is created in LUSID",
      "application": "Lusid",
      "headerSchema": [
        { 
          "name": "eventType",
          "type": "String" 
        },
        { 
          "name": "requestId",
          "type": "String" 
        },
        { 
          "name": "userId",
          "type": "String" 
        },
        { 
          "name": "action",
          "type": "String" 
        },
        { 
          "name": "entityType",
          "type": "String" 
        },
        { 
          "name": "timestamp",
          "type": "String" 
        },
        { 
          "name": "href",
          "type": "String" 
        }
      ],
      "bodySchema": [
        { 
          "name": "portfolioScope",
          "type": "String" 
        },
        { 
          "name": "portfolioCode",
          "type": "String" 
        }
      ]
      "href": "https://<your-domain>.lusid.com/notification/api/eventtypes/PortfolioCreated"
    },
    ...
  ],
}
```

You apply your filter in the `filter` field when you [create a subscription](/v1/docs/how-do-i-subscribe-to-an-event) to that event.

Note you must prefix attributes appropriately with either `Header.` or `Body.`. For example, you could subscribe to the `PortfolioCreated` event only when a portfolio is created in a particular scope, and by a particular user:

```json
"matchingPattern": {
    "eventType": "PortfolioCreated",
    "filter": "Header.userId eq '00uji4twb4jDcHGjN2p8' and Body.portfolioScope eq 'Finbourne-Examples'"
}
```

Applying the above filter using the LUSID web app might look as follows: ![](https://cdn.document360.io/d575ad81-c0ed-4980-bbd1-d59ac5c3de82/Images/Documentation/image(740).png)