Contact emails
vk...@google.com
Explainer
https://github.com/WICG/sub-apps
Specification
https://wicg.github.io/sub-apps
Design docs
https://github.com/WICG/sub-apps
Summary
Sub apps allow developers to create multiple apps under a single Isolated Web App ([IWA](
https://chromeos.dev/en/web/isolated-web-apps)) installation. Each Sub app has its own distinct name, icons and OS integrations.
Sub apps appear on the desktop shelf with a distinct identity from the parent IWA, offering separate OS capabilities, such as file type association. This allows a single software package to present different, isolated functionalities to the user while maintaining a single, unified IWA install and update process.
There are three new enterprise policies available to control the Sub apps API:
- [DefaultSubAppsWithoutPromptsSetting](
https://chromeenterprise.google/policies/#DefaultSubAppsWithoutPromptsSetting) specifies globally (for all IWAs) if user permission prompts are required to install Sub apps. The policies below can override this default.
- [SubAppsWithoutPromptsAllowedForOrigins](
https://chromeenterprise.google/policies/#SubAppsWithoutPromptsAllowedForOrigins) specifies a list of IWA URLs that can add or update Sub apps without user permission prompts.
- [SubAppsWithoutPromptsBlockedForOrigins](
https://chromeenterprise.google/policies/#SubAppsWithoutPromptsBlockedForOrigins) specifies a list of IWA URLs that can add Sub apps with user permission prompts only.
Blink component
Content>WebApps
Web Feature ID
Missing feature
Motivation
Without this API developers are forced into splitting the application into separate ones which complicates distribution or bundle everything into a single huge application that can potentially confuse users.
Initial public proposal
https://github.com/WICG/proposals/issues/282
TAG review
Tag does not review Isolated Web Apps.
It was stated publicly here
https://github.com/w3ctag/design-reviews/issues/842#issuecomment-2917031448
TAG review status
Pending
Goals for experimentation
None
Risks
Interoperability and Compatibility
Other browsers may choose to implement this API.
Gecko: No signal
WebKit: No signal
Web developers: No signals
Other signals:
Security
Sub-apps share origin identity and all local data stores with their parent app, exposing them to standard same-origin security boundaries.
Permission grants are shared bidirectionally; granting a permission to a sub-app automatically extends that permission to the parent app.
There is a risk of identity spoofing and launcher hijacking, which is mitigated by restricting the API to isolated contexts.
Registering custom OS integrations requires explicit user approval to prevent unauthorized protocol handling or file type hijacking.
WebView application risks
Does this intent deprecate or change behavior of existing APIs,
such that it has potentially high risk for Android WebView-based
applications?
No information provided
Debuggability
There's no special devTools support for this feature.
It is possible to add sub apps, remove and list them via devTools console raw javascript execution.
Will this feature be supported on all six Blink platforms
(Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?
No
This feature is implemented on desktop platforms, although it will only be available to the end users on platforms that support Isolated Web Apps, which is currently only ChromeOS.
Android is excluded because installing arbitrary apps is complicated there and needs additional work.
No
JS API interface tests are in third_party/blink/web_tests/external/wpt/subapps.
https://wpt.fyi/results/subapps?label=master&label=experimental&aligned&q=subapps
More complete tests that cover all cases are in chrome/browser/web_applications/sub_apps/sub_apps_service_impl_browsertest.cc
DevTrial instructions
https://github.com/vkrot-cell/subapps-demo
Flag name on about://flags
#enable-sub-apps
Finch feature name
SubApps
Rollout plan
Will ship enabled for all users
Requires code in //chrome?
True
Tracking bug
https://buganizer.corp.google.com/issues/414729785
Launch bug
https://launch.corp.google.com/launch/4466158
Measurement
Separate programmatic counters for the .idl methods and attributes (via MeasureAs) are included to track the stats for API usage:
SubAppsAdd
SubAppsRemove
SubAppsList
Availability expectation
Feature is available only in Isolated Web Apps on desktop platforms.
https://chromestatus.com/feature/5146307550248960
Adoption expectation
Expected to be used initially by a small number of developers inside Isolated Web Apps.
Adoption plan
Working directly with developers that are planning to rely on the API.
Estimated milestones
| Shipping on desktop | 153 |
| DevTrial on desktop | 150 |
Anticipated spec changes
Open questions about a feature may be a source of future web compat or
interop issues. Please list open issues (e.g. links to known github
issues in the project for the feature specification) whose resolution
may introduce web compat/interop risk (e.g., changing to naming or
structure of the API in a non-backward-compatible way).
No information provided
Link to entry on the Chrome Platform Status
https://chromestatus.com/feature/6260680824061952?gate=4662441016426496
Links to previous Intent discussions
Intent to Prototype:
https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6a3408fc.3af95f39.17d45c.0404.GAE%40google.com