starl3xx.fun / algo
X Algo Watch
Report
Every Sunday: what actually moved in the open-source ranking code behind X’s For You feed (xai-org/x-algorithm), diffed against last week’s mirror and translated for people who post. Read from the code, not from folklore. One post, Sunday night, Central; quiet weeks get one standing rule instead.
User actions that increase your reach
param.rs at 4c5cfe8, 26 September 2026bc8e5f0, four issues agoRead a multiple as a ratio between two weights, not as a promise about reach: each one multiplies a predicted probability rather than a count, so a reply weighted ten times a like is not a reply being worth ten likes. These are defaults in open-source code, and the repo says itself that they may not match production. Since issue 005 a separate ranking service returns the final score, and once it has loaded its config it sums these same weights from its own copy of these nine defaults, which matches this one. Without that config, or when the call to it fails, home-mixer’s own sum of these weights is served.
And two things you cannot earn
×0.625 is 0.25 + 0.75 × 0.5, from AuthorDiversityDecay at 0.5 and AuthorDiversityFloor at 0.25 in vm-ranker/params.rs. The ranking service applies them once it has loaded its config, which its open-source startup flag leaves off, and not at all when home-mixer’s call to it fails; whether X runs it that way is not in the repo. Until issue 005 this page said ×0.5 for every extra post, but only the part above the floor halves, and the formula is the same at every commit this series has read. 48h is MAX_POST_AGE in home-mixer/params/config.rs, written there as 48 * 60 * 60.
Updates
This week · 27 September 2026Issue № 005 (commit 4c5cfe8)The final score now computed in a separate ranking service, the repeat-author and out-of-network multipliers moved there rather than removed, a correction to this series’ own repeat-author arithmetic, the text NSFW label no longer a drop for adults in out-of-network recommendations, and a Brazil election list ten accounts longerHow it works
- Diff the recorded commit against HEAD.
- Parse every default in
param.rs,config.rsand the ranking service’sparams.rsat both ends, and compare by name, so no number is retyped. - Write what moved, and what it means for posting.
- Check every figure back against the diff.
- starl3xx reviews. Nothing ships unread.
