Capturing sessions

BugSnag tracks the number of “sessions” that happen within your application. This allows you to compare stability scores between releases and helps you to understand the quality of your releases.

Sessions are captured and reported by default. This behavior can be disabled using the autoTrackSessions configuration option.

Automatic tracking

BugSnag will automatically report a session each time the app is launched or enters the foreground after being in the background for at least 60 seconds.

Manual session handling

If you want control over what is deemed a session, you can switch off automatic session tracking with the autoTrackSessions option, and manage the session lifecycle using startSession(), pauseSession() and resumeSession() on the Bugsnag client.

You should call these methods at the appropriate time in your application’s lifecycle when you wish to have an active session. Any errors which occur in your application outside of a session will still be reported to BugSnag but will not count towards your application’s stability score.


Starts a new session to which subsequent handled and unhandled events will be attributed to.

If there is already an active session, it will be replaced with a new one. Use resumeSession if you only want to start a session when one doesn’t already exist.



Prevents further events being attributed to the current session until the session is resumed or a new session is started.



Resumes tracking events against the current session, if it was previously paused. If there is was no previous session, a new session is started. This method returns true if there was a session to resume or false if a new session was created.


Discarding and amending sessions

The data captured in a session can be customized by adding an onSession callback as part of your BugSnag configuration.

  onSession: function (session) {
    var userId = getMyUserIdentifier() // a custom user resolver

As with an onError callback, the return value from onSession determines whether the session will be delivered to BugSnag and so can be used to discard sessions if required.

Adding and removing callbacks

We recommend adding callbacks through the onSession configuration option to ensure that it is registered as soon as BugSnag starts. However, the following methods are provided to allow callbacks to be added and removed whilst the application is running:

var cb = function(session) { /* ... */ };

The Session object

The following information is available on a Session object, the representation of session information available in an onSession callback.

property type description
app Object A subset of the app data contained in error events.
device Object A subset of the device data contained in error events.
id String A unique ID for the session.
startedAt Date The timestamp that the session was started.
getUser/setUser Object The active user for the session