The session_level_signals body field the feed surfaces carry: a session
state snapshot (surface navigation trail, video counters, ranking-session
window). app_session_navigation is the current screen plus when it came to
front, read from the navigation state; the ranking-session window derives
from the request clock (local hour, day, weekend); the session counters are
zero for a just-started cold session. Key order mirrors the 448 capture.
The 451 build (extendedSessionSignals, the profile's launchWire)
inserts the app-session and container-module block at its recorded
positions. Where the recordings show a one-surface session (the 448
feed/timeline capture), the block reuses its measured values: 1 for the
container-module and surface counts and the current surface's nav depth,
0 for the visit entropy and the phase/output-volume values, 1000 for
the exploration breadth. The 451-only hashes and new-edge rates have no
one-surface recording, and a one-surface path hash is not derivable from
the library's model: 0 and 1000 there are unobserved placeholders,
present only to satisfy the build's mandatory key set, and are never
presented as a modelled session's values. An Android 451 feed/timeline
whose session has the feed as its only surface — or the app's own formulas
for those keys — replaces them. The recording's values for the dwell
hashes and entropies, the gap statistics, the hop count and the transition
map are its two-surface session's measured history — the remaining
difference, not a wire drift.
The
session_level_signalsbody field the feed surfaces carry: a session state snapshot (surface navigation trail, video counters, ranking-session window).app_session_navigationis the current screen plus when it came to front, read from the navigation state; the ranking-session window derives from the request clock (local hour, day, weekend); the session counters are zero for a just-started cold session. Key order mirrors the 448 capture.The 451 build (
extendedSessionSignals, the profile'slaunchWire) inserts the app-session and container-module block at its recorded positions. Where the recordings show a one-surface session (the 448feed/timelinecapture), the block reuses its measured values:1for the container-module and surface counts and the current surface's nav depth,0for the visit entropy and the phase/output-volume values,1000for the exploration breadth. The 451-only hashes and new-edge rates have no one-surface recording, and a one-surface path hash is not derivable from the library's model:0and1000there are unobserved placeholders, present only to satisfy the build's mandatory key set, and are never presented as a modelled session's values. An Android 451feed/timelinewhose session has the feed as its only surface — or the app's own formulas for those keys — replaces them. The recording's values for the dwell hashes and entropies, the gap statistics, the hop count and the transition map are its two-surface session's measured history — the remaining difference, not a wire drift.