v1.9, December 2021
Version 1.9 of the Exposure Notifications API introduces
variantOfConcern, which provides the option of
labeling TEKs associated with variants of concern.
v1.8, January 2021
Version 1.8 of the Exposure Notifications API includes:
requestPreAuthorizedTemporaryExposureKeyRelease()methods for preauthorization of TEK release
- Check that the client app is in the foreground before returning results as
- Various settings UX changes
- Move "exposure checks" and "delete random IDs" to the overflow menu
- Add app details page that includes information about the
preauthorization requests from
- Change the weekly service enabled notification to be shown monthly
- Skip incrementing quota when
deviceSupportsLocationlessScanning()in favor of the more informative
- Wrap all API calls in a timeout
- General bug fixes and system hardening
Preauthorization of TEK release
This feature allows client apps to optionally request that users preauthorize
sharing their anonymous keys in case of a positive test result. During
enrollment, the app can request that users set up automatic sharing by calling
and displaying the consent screen via
if required. If consent is given, the app is able to
retrieve keys once in the next 5 days. This feature is useful when a user had a
test done recently, or is about to be tested for COVID-19.
If a user denies consent, then the client app receives the
By requesting preauthorization to share the user's keys in case of a positive
test, other users that might have come in contact with them can receive
notifications without the user’s action. When the app wants to upload keys, for
example if a test result is positive, it should call
The keys are delivered via a broadcast with the
action, the moment the user unlocks their phone. A notification is also
displayed to the user.
getTemporaryExposureKeyHistory() foreground check
If a client is not in the foreground when
is invoked, then the
error code is immediately returned. This prevents unexpected user
experiences where the dialog could be shown on top of other, non-Exposure
Notification-related tasks, and also aligns with the iOS implementation.
Settings UX changes
"Exposure checks" and "Delete random IDs"
The Exposure checks and the Delete random IDs button have both been moved from the main settings list to the overflow menu. There have been no functional changes to these options.
App details UX
When tapping an app from the main settings screen, a user is now directed
to a details screen where they can open the app or modify settings
associated with the
API when applicable.
Monthly service enabled notifications
Notifications informing the user that Exposure Notifications are active have been moved from weekly to monthly.
provideDiagnosisKey() quota changes
If the call to
fails for any reason, it will no longer be counted against the quota for that
method, allowing client applications to freely retry if desired.
is deprecated in favor of the
API, which provides more details about whether Exposure Notifications
can currently be supported on the device.
API call timeouts
All API calls now time out after 2 minutes, after which a failure response will
be delivered to the caller.
is special cased to time out after 60 minutes as a large number of keys and
files can take a significant amount of time to process on low-end devices.
v1.7.2, October 2020
Version 1.7.2 of the Exposure Notifications API is a small bug fix release on top of v1.7 including the following:
- Bug fix which allows for passing in a large number of key files to
provideDiagnosisKeyson low-end devices without crashing the service.
v1.7, September 2020
Version 1.7 of the Exposure Notifications API includes the following changes, which aim to fix common pain points and address some minor pending items:
- Discarding of
- App uninstall cleanup
- Preparing for future onboarding flow on the Play Store
- Fixes for crashes and bugs, including fixes for localization string in settings
New getStatus() method
We received feedback that the process was cumbersome for determining whether Exposure Notifications can be used on a given device, because it required first checking whether the device has the right settings enabled.
method moves that complexity to the API level and returns a
value. This makes it easier and more straightforward to determine whether
Exposure Notifications is usable on a device.
Discarding of ExposureWindow objects with infectiousness=NONE and reportType=REVOKED
Exposures to other users should not contribute to the
value if their diagnosis keys are mapped by configuration to either of the
infectiousness=NONE: Their days since onset of symptoms correspond with very low infectiousness
reportType=REVOKED: They have been revoked
Prior to Exposure Notifications v1.7, we recommended assigning a weight of
for exposure data with these values. Because these factors wouldn’t contribute
to the final count, we added the optimization to drop them automatically for
risk value computation.
App uninstall cleanup
When an app is uninstalled, the Exposure Notifications system deletes pending matching requests to keep any residual untraceable tokens from remaining on the device.
Preparing for future onboarding flow on the Play Store
We added an Exposure Notifications API component that enables a future optimization of the app onboarding flow on the Google Play Store. This feature will allow users to enable Exposure Notifications on their device during the installation process of an Exposure Notifications app.
New six-hour WakeUpService cadence
WakeUpService now runs every six hours instead of daily.
This change in frequency should help apps to not to be terminated based on system resource optimizations.
v1.6, August 2020
Version 1.6 of the Exposure Notifications API is a patch update to v1.5 that includes:
- Addition of data to the existing
ExposureWindowclass, to help you optionally design your own definitions of meaningful exposures
- Daily exposure summaries
- Locationless scanning
- System user experience changes
- The new
ExposureWindow now has infectiousness and calibrationConfidence
ExposureWindow adds two new fields to allow public health authorities
(PHAs) to estimate the risk score for a set of exposure data:
infectiousness represents the level of virality
associated with a given key.
We have gradually improved the calibrated values for supported devices, now based on internal calibrations and statistical modeling. In v1.5, we started including calibration confidence in advertisements, and now with v1.6 you can benefit from these enhancements.
calibrationConfidence provides an estimation
of the level of accuracy of the calibration associated with the exposure’s
New diagnosis key data mapping configuration
We have added the data structure
DiagnosisKeysDataMapping, which contains
configuration parameters to map diagnosis key data to
In v1.6, these parameters are applied at matching time, when calling
Changing the configuration via
setDiagnosisKeysDataMapping() won't modify
ExposureWindows for keys provided in past calls, but we might change this behavior
in future versions. If
setDiagnosisKeysDataMapping() is called twice within 7 days,
the second call has no effect and raises an exception with status code
Daily exposure summaries
v1.6 completes the new set of risk score computation functionality started with
v1.5. With the addition of
and the related data structures
you now have a predefined algorithm to compute risk score based on PHA-defined
thresholds and weights for the different parameters in
DailySummaryConfig: In v1.6, any
ExposureWindow objects with
may go into your daily exposure summary computation. When calling
and a weight is specified for
infectiousness=NONE in the
object, we recommend setting the weight to
indicates no risk of exposure. A future version of the API
may disregard a mapping value for
infectiousness=NONE may be dropped
before computing the risk scores.
With Android 11, version 1.6 and higher of Exposure Notifications works without having to enable Location Services. This means there are now additional cases in which it is not necessary to prompt users to manually enable this setting.
To simplify checking when locationless scanning is available on the device, we
have updated the SDK (v1.6.1) to include
This method returns a boolean value indicating whether a given device supports
locationless scanning. (Note that as of the v1.7 SDK, we recommend checking via
a different approach.)
Report type transitions of previously reported TEKs
v1.6 supports changing the
value associated with a particular Temporary Exposure Key (TEK), allowing public
health authorities (PHAs) to update reported cases to a more accurate state as
they gather more data. Because TEKs can go through a single report type
transition, additional transitions will be rejected if more than one is
attempted. The following transitions are supported:
System user experience changes
We have added a new tile to the Settings page linking to guidance when a user has Exposure Notifications permanently disabled by the PHA’s server.
New API method: getVersion()
V1.6 includes the new
function, which provides information about the module version installed on the
Debug mode changes
We have added a new option in debug mode: Return today’s TEK with shortened
rolling period. This functionality enables testing the behavior of early TEK
This enables you to test the compatibility of your app and server with early TEK
release, thereby allowing you to prepare in advance for this feature before it
is activated in production with upcoming updates.
v1.5, July 2020
Version 1.5 of the Exposure Notifications API started rolling out on 2020-07-09. There are no behavior changes in existing functionality, but we have introduced bug fixes and new features that aim to provide developers with more data and make the API easier to test and debug. See the following sections for the new additions.
ExposureWindow replaces ExposureInformation
Version 1.5 introduces the
The class provides a new way to determine the risk associated with an exposure,
ExposureSummary. To use the new method, use the
ExposureWindow mode. Note the following changes:
- New quota restrictions on the
provideDiagnosisKeys()method: 6 per day when using the framework in ExposureWindow mode versus the 20 per day in v1 mode.
- Developers can use more granular data from
ScanInstancesfor risk score computation.
- Deprecation (but not removal, for backwards compatibility) of
ExposureWindow mode and v1 mode
We have introduced the use of a special
token to switch between working
default behavior for apps that were built for v1 is to continue working as
designed when running on v1.5—we call this v1 mode. You can opt to use
ExposureWindow mode by calling
provideDiagnosisKeys() with the special value
for the parameter
Multiple batch group support for provideDiagnosisKeys
provideDiagnosisKeys() will support passing multiple batch groups
(signatories) in a single method call, as a way to support different server
interoperability use cases.
Debug mode changes
The Debug mode changed with version 1.5 of the API. You can read more about the changes in the Debug mode topic.
System user experience changes
Settings screen updates for more clarity, transparency, and control: We have made it easier for users to understand when Exposure Notifications are on or off, and added a simple way to enable or disable the feature from settings (Settings > Google > COVID-19 Exposure Notifications). This includes:
- Adding a new indicator at the top of settings to make it clear when the feature is on or off.
- Removing most of the content and options when no Exposure Notifications app is installed, since they aren’t relevant.
Adding a new option to reactivate Exposure Notifications from Settings: users need to enable Exposure Notifications from the app before the API is enabled on the device. We introduced the capability to toggle Exposure Notifications off through Settings in previous versions. As of v1.5, users can also turn it back on from the same setting.
Figure 1. Updated Settings screen
App force-stop improvements: if an app has been force-stopped in the background, the Exposure Notifications service will wake it up again automatically.
Reference documentation updates
The reference implementation app has been adjusted to use ExposureWindow mode. We also updated the reference diagnosis key server implementation to use the verification server reference.
For an account on recent changes in the documentation, refer to the documentation change log.