Recency decay: the whole score halves every 72 hours since the discussion’s last activity. The activity window is 288 hours (12 days); older activity doesn’t count at all.
What is never an input
Views, impressions, dwell time, scroll depth; the platform does not measure them.
Your identity, history, or behavior; same query, same results, for everyone.
Payment; paid visibility is rejected on principle, by platform law.
The saved-current resurfacing formula; beacon-resurface-v1
“Saved & stirring” surfaces a thread you saved only when it has genuinely grown since you last read it, ranked by exactly this:
priority = (new posts since your last read + new unique voices since your last read) × 0.5(hours since newest post ÷ 72)
A saved thread needs at least 1 new post to resurface, and at most 5 resurfaced threads ride one feed load; the feed still ends. (Both are rails.)
The only personal signal is your own watermark; the moment you last read the thread. A time, and nothing else. Your saves are private to your face, never a ranking input for anyone else, and never counted or shown to authors.
Versioning & governance
This is v1; 2026-07-11. Changes are announced, dated, and diffable; the weights above are rails (poll-adjustable within bounds), and the ratified future is community tunability by governance poll: new lenses are just new published formulas plugged into the same machinery. Exact starting weights are a flagged build-time derivation (the corpus defers final weights to real usage data); the inputs themselves are ratified law.