Permissions API

Note: This feature is available in Web Workers.

The Permissions API provides a consistent programmatic way to query the status of API permissions attributed to the current context, such as a web page or worker. For example, it can be used to determine if permission to access a particular feature or API has been granted, denied, or requires specific user permission.

Concepts and usage

Historically different APIs handle their own permissions inconsistently — for example the Notifications API provided its own methods for requesting permissions and checking permission status, whereas the Geolocation API did not. The Permissions API provides the tools to allow developers to implement a consistent user experience for working with permissions.

The permissions from this API effectively aggregate all security restrictions for the context, including any requirement for an API to be used in a secure context, Permissions-Policy restrictions applied to the document, requirements for user interaction, and user prompts. So, for example, if an API is restricted by permissions policy, the returned permission would be denied and the user would not be prompted for access.

The permissions property has been made available on the Navigator object, both in the standard browsing context and the worker context (WorkerNavigator — so permission checks are available inside workers), and returns a Permissions object that provides access to the Permissions API functionality.

Once you have this object you can then use the Permissions.query() method to return a promise that resolves with the PermissionStatus for a specific API.

Requesting permission

If the permission status is prompt, the user must acknowledge a prompt to grant access to the feature.

The mechanism that triggers this prompt will depend on the specific API — it is not defined as part of the Permissions API. Generally the trigger is code calling a method to access or open the feature, or that registers for notifications from the feature that will subsequently access it.

Note that not all features require a prompt. Permission might be granted by a Permission Policy, implicitly by transient activation, or via some other mechanism.

Revoking permission

Permission revocation is not managed by the API. More specifically, a Permissions.revoke() method was proposed, but has since been removed from those browsers where it was implemented.

Users can manually remove permission for particular sites using browser settings:

  • Firefox: Hamburger Menu > Settings > Privacy & Security > Permissions (then select the Settings button for the permission of interest).
  • Chrome: Hamburger Menu > Settings > Show advanced settings. In the Privacy section, click Content Settings. In the resulting dialog, find the Location section and select Ask when a site tries to…. Finally, click Manage Exceptions and remove the permissions you granted to the sites you are interested in.

Permission-aware APIs

Not all APIs' permission statuses can be queried using the Permissions API. A non-exhaustive list of permission-aware APIs includes:

Interfaces

Permissions

Provides the core Permission API functionality, such as methods for querying and revoking permissions.

PermissionStatus

Provides access to the current status of a permission, and an event handler to respond to changes in permission status.

Extensions to other interfaces

Provides access to the Permissions object from the main context and worker context respectively.

Examples

We have created an example called Location Finder. You can run the example live, view the source code on GitHub, or read more about how it works in our article Using the Permissions API.

The Permissions.query() example also so shows code that tests most permissions on the current browser and logs the result.

Specifications

Specification
Permissions

Browser compatibility

api.Permissions

api.Navigator.permissions

api.WorkerNavigator.permissions

See also