This module provides information about your extension and the environment it’s running in.

It also provides messaging APIs enabling you to:

• Communicate between different parts of your extension. For advice on choosing between the messaging options, see Choosing between one-off messages and connection-based messaging.

• Communicate with other extensions.

• Communicate with native applications.

Types

• : Represents one end of a connection between two specific contexts, which can be used to exchange messages.

• : Contains information about the sender of a message or connection request.

• : Identifies the browser’s operating system.

• : Identifies the browser’s processor architecture.

• : Contains information about the platform the browser is running on.

• : The deprecated enumeration value representing Google Native Client architecture. Consider migrating to PlatformArch, which is supported by Safari and Mozilla, and represents the true CPU architecture and conveys correct bitness information on ARM.

• : Result of a call to .

• : The reason that the event is being dispatched.

• : The category of warning that dispatched the event.

• : The severity of warning that dispatched the event.

• : The reason that the event is being dispatched.

Properties

• : This value is set when an asynchronous function has an error condition that it needs to report to its caller.

• : The ID of the extension.

Functions

• : Retrieves the Window object for the background page running inside the current extension.

• : Returns the document ID of any window global or frame element.

• : Opens your extension’s options page.

• : Gets details about the contexts associated with the extension.

• : Gets the frame ID of any window global or frame element.

• : Gets an object representation of the complete manifest.json file.

• : Given a relative path from the manifest.json to a resource packaged with the extension, returns a fully-qualified URL.

• : Gets the extension version string from the manifest.json file version key. The returned version may differ from the string in the file because the browser can parse and serialize it.

• : Sets a URL to be visited when the extension is uninstalled.

• : Reloads the extension.

• : Checks for updates to this extension.

• : Establishes a connection from a content script to the main extension process, or from one extension to a different extension.

• : Connects the extension to a native application on the user’s computer.

• : Sends a message to event listeners within your extension or a different extension. Similar to but only sends a single message, with an optional response.

• : Sends a message from an extension to a native application.

• : Returns information about the current platform.

• : Returns information about the browser in which this extension is installed.

• : Returns a DirectoryEntry for the package directory.

Events

• : Fired when a profile that has this extension installed first starts up. This event is not fired when an incognito profile is started.

• : Fired when the extension is first installed, when the extension is updated to a new version, and when the browser is updated to a new version.

• : Sent to the event page just before the extension is unloaded. This gives the extension an opportunity to do some cleanup.

• : Sent after to indicate that the extension won’t be unloaded after all.

• : Fired when an update is available, but isn’t installed immediately because the extension is currently running.

• : Fired when an update for the browser is available, but isn’t installed immediately because a browser restart is required.

• : Fired when a connection is made with either an extension process or a content script.

• : Fired when a connection is made with another extension.

• : Fired when a connection is made with a user script registered by the extension.

• : Fired when a message is sent from either an extension process or a content script.

• : Fired when a message is sent from another extension. Cannot be used in a content script.

• : Fired when a message is sent from a user script registered by the extension.

• : Fired when a runtime performance issue is detected for the extension.

• : Fired when the device needs to be restarted.

Browser compatibility

This API is based on Chromium’s chrome.runtime API. This documentation is derived from runtime.json in the Chromium code.