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Automatic Event Tracking

The SDK automatically tracks key lifecycle events without any code from you.

Automatically Tracked Events​

first_open​

Tracks when a user opens your app for the very first time after installation. Logged only once per device.

When it fires:

  • First app launch after installation
  • Only fires once per device lifetime

session_start​

Tracks when a user starts a new session. A new session begins when the app comes to the foreground after being in the background longer than the session timeout period.

When it fires:

  • App is opened from closed state
  • App returns to foreground after session timeout (default: 30 minutes)

Customize session timeout:

B2MetricAnalyticsConfig(
  apiKey = "YOUR_API_KEY",
  assumedSessionTimeInMinutes = 15 // 15-minute timeout
)

session_end​

Tracks when a user's session ends. Fires when the app remains in the background longer than the configured session timeout.

When it fires:

  • Next time app comes to foreground after extended background time

How Sessions Work​

The SDK uses Android's ProcessLifecycleOwner to automatically detect foreground/background transitions.

Session continuation (within timeout):

User opens app                    → session_start (session_id: "abc123")
User interacts for 10 minutes     → Session continues
User backgrounds app for 5 min   → Session still active (under 30-min timeout)
User returns to app               → Same session continues (session_id: "abc123")

New session (timeout exceeded):

User opens app                    → session_start (session_id: "abc123")
User backgrounds app for 35 min  → Session expires
User returns to app               → session_end (session_id: "abc123", duration: 600s)
                                  → session_start (session_id: "def456")