---
source_url: "https://openmeter.io/docs/integrations/notifications/rule"
title: "Rule | OpenMeter by Kong"
mirrored_at: 2026-08-05T15:39:28.736Z
host: openmeter.io
cited_in_42a: true
mirror_canonical: "https://index.42a.ai/openmeter.io/docs/integrations/notifications/rule"
---

> **Original source:** https://openmeter.io/docs/integrations/notifications/rule

## [#What is a Rule?](#what-is-a-rule)

The rule specifies what conditions should trigger an event. Given that OpenMeter can handle millions of ingested events per day, it is not a good practice to send notifications to the customer's backend system at this rate.

Rules solve this issue by allowing our customers to specify the events they are interested in.

### [#Example](#example)

Let's say we have a feature called `llm_tokens` that measures token usage for our large language models.

Each end user is allowed to use 10,000 of those tokens per month. They have a metered entitlement with this hard limit.

Our backend needs to be notified when users reach 80% of their quota so that we can send them a notification email to buy more tokens.

In this example, the backend is not interested in always getting an updated balance; it would just need to be notified when it reaches the 80% mark. By defining a Rule with an 80% threshold, we achieve this behavior.

## [#Rule types](#rule-types)

Each rule has a `type` to support multiple event types. OpenMeter supports the following rule types:

Type

[Entitlement Balance Threshold](https://openmeter.io/docs/integrations/notifications/entitlements#entitlement-balance-change)

`entitlements.balance.threshold`

Sends a notification a specified usage threshold has been reached on an entitlement

[Entitlement Reset](https://openmeter.io/docs/integrations/notifications/entitlements#entitlement-reset)

`entitlements.reset`

Sends a notification if an entitlement has been reset either manually or automatically

[Invoice Created](https://openmeter.io/docs/integrations/notifications/invoices)

`invoice.created`

Sends a notification on invoice creation

[Invoice Updated](https://openmeter.io/docs/integrations/notifications/invoices)

`invoice.updated`

Sends a notification when an invoice changes state