Foryx
The For-You feed, from the inside.
What it is
Foryx is a transparent feed ranker that shows exactly how a For-You algorithm decides what surfaces and why. The signature technique combines an affinity, interest, and engagement score scaled by an exponential recency decay, followed by a greedy diversity re-rank with an author-repeat penalty, and you can flip between ranked and chronological to watch posts rise and sink. It is a from-scratch, dependency-light build you can download and run locally.
A pure feed ranker: affinity × interest × engagement, scaled by an exponential recency decay, then a greedy diversity re-rank with an author-repeat penalty. Flip ranked vs chronological and watch posts rise and sink. 12 tests on the scoring, interleaving, and explanations.
What's inside
The full source, the tests, and CI. Open it, read it, change it. A zero-dependency core, free, in the MIT spirit.
Run it after unzip
pnpm install && pnpm dev