index.md

---

title: events.Rule
slug: Mozilla/Add-ons/WebExtensions/API/events/Rule
page-type: webextension-api-type
tags:
  - API
  - Add-ons
  - Extensions
  - Non-standard
  - Reference
  - Rule
  - Type
  - WebExtensions
  - events
browser-compat: webextensions.api.events.Rule

---

{{AddonSidebar()}}

Description of a declarative rule for handling events.

Type

Values of this type are objects. They contain the following properties:

• id {{optional_inline}}

  • : string. Optional identifier that allows referencing this rule.

• tags {{optional_inline}}

  • : array of string. Tags can be used to annotate rules and perform operations on sets of rules.

• conditions

  • : array of any. List of conditions that can trigger the actions.

• actions

  • : array of any. List of actions that are triggered if one of the conditions is fulfilled.

• priority {{optional_inline}}

  • : integer. Optional priority of this rule. Defaults to 100.

Browser compatibility

{{Compat}}

{{WebExtExamples}}

Note: This API is based on Chromium's chrome.events API. This documentation is derived from events.json in the Chromium code.