x-algorithm changelog (unofficial)

Unofficial, community-maintained project. Not affiliated with, endorsed by, or operated by X Corp. or xAI. Notes are generated from the public git history of xai-org/x-algorithm and may contain mistakes; the upstream diff is the source of truth.

· 8b25829 · 41 files, +2,877/−1,828

"Dwell regret" scoring gate removed; Under the Hood shows legal withholding

paramsscorers
  • Removed scorer value_model_gate (537 lines). It was a per-viewer linear gate: it scored features from the viewer's recent action sequence and compared the score to a threshold to decide whether ranking_scorer should use the alternative "dwell regret" scoring path. Inside the hysteresis band, a hash of the user ID made the call. With it go 18 params: every DwellRegret* alpha/negative/gate/temperature param and ValueModelMode. ranking_scorer.rs loses 465 lines and gains 12.
  • New param PhoenixColdStartMaxResults (default 0, i.e. off). PhoenixRetrievalMOEInferenceClusterId changes from "Experiment2Memy04" to "Experiment3Memy04".
  • Under the Hood: the README's "September 18th, 2026" note says reports now show whether an account's or post's visibility was limited for legal compliance (e.g. withheld in a specific country). That matches the changes to UthPctdAccountTakedownEventsJob.scala and underTheHoodLabels.strato.
  • Visibility filtering gets a new tes_composite hydration path and a batch evaluate_tweets API.

Full analysis → Summary: hand-written notes, checked against the diff

Automatic analysis

Config parameters (param! defaults)

ParameterFeature-switch keyOldNew
PhoenixRetrievalMOEInferenceClusterId
home-mixer/params/param.rs		rust_home_mixer_phoenix_retrieval_moe_inference_cluster_id"Experiment2Memy04""Experiment3Memy04"
Added parameterTypeDefaultFile
PhoenixColdStartMaxResultsu320home-mixer/params/param.rs
Removed parameterTypeLast defaultNote
DwellRegretAlphaFavoritef641.0removed from home-mixer/params/param.rs
DwellRegretAlphaQuotef641.0removed from home-mixer/params/param.rs
DwellRegretAlphaReplyf641.0removed from home-mixer/params/param.rs
DwellRegretAlphaRetweetf641.0removed from home-mixer/params/param.rs
DwellRegretAlphaSharef641.0removed from home-mixer/params/param.rs
DwellRegretAlphaShareViaCopyLinkf641.0removed from home-mixer/params/param.rs
DwellRegretAlphaShareViaDmf641.0removed from home-mixer/params/param.rs
DwellRegretDwellFloorf641.0removed from home-mixer/params/param.rs
DwellRegretGateBiasf641.033918removed from home-mixer/params/param.rs
DwellRegretGateHysteresisBandf640.0removed from home-mixer/params/param.rs
DwellRegretGateThresholdf64-0.634264removed from home-mixer/params/param.rs
DwellRegretGateWeightsString"seq_len:0.530298,n_fav:-0.082139,n_reply:0.485541,n_rt_quote:0.056561,n_vqv:-0.removed from home-mixer/params/param.rs
DwellRegretNegBlockAuthorf64-8000.0removed from home-mixer/params/param.rs
DwellRegretNegMuteAuthorf64-15000.0removed from home-mixer/params/param.rs
DwellRegretNegNotInterestedf64-10000.0removed from home-mixer/params/param.rs
DwellRegretNegReportf64-60000.0removed from home-mixer/params/param.rs
DwellRegretTemperaturef6410.0removed from home-mixer/params/param.rs
ValueModelModeString"weighted"removed from home-mixer/params/param.rs

Pipeline components

KindChangeFile
Scorerremovedhome-mixer/scorers/value_model_gate.rs
Scorermodifiedhome-mixer/scorers/ranking_scorer.rs
Side effectmodifiedhome-mixer/side_effects/reranking_kafka_side_effect.rs
Side effectmodifiedhome-mixer/side_effects/scored_stats_side_effect.rs
Candidate sourcemodifiedhome-mixer/sources/phoenix_moe_source.rs
Candidate sourcemodifiedhome-mixer/sources/phoenix_source.rs
Candidate sourcemodifiedhome-mixer/sources/phoenix_topics_source.rs
Candidate hydratormodifiedvisibility-filtering/hydration/exclusive_content_hydrator.rs
Candidate hydratormodifiedvisibility-filtering/hydration/gizmoduck_hydrator.rs
Candidate hydratormodifiedvisibility-filtering/hydration/socialgraph_hydrator.rs
Candidate hydratormodifiedvisibility-filtering/hydration/tes_hydrator.rs
Candidate hydratormodifiedvisibility-filtering/hydration/viewer_hydrator.rs

Modules touched

ModuleFiles addedModifiedRemovedLines +Lines −
visibility-filtering/2180+1,829−495
home-mixer/081+116−1,135
phoenix/060+639−149
visibility-filtering-client/010+250−0
under-the-hood/020+23−40
grox/020+15−9
(repo root)/010+5−0

Files (41)

Show file list
PathLinesNote
MREADME.md+5/−0
Mgrox/flows/ptos/constants.py+1/−0
Mgrox/flows/ptos/task_safety_ptos_media_injected_adult_infrared_video_spam_detection.py+14/−9
Mhome-mixer/params/param.rs+8/−110
Mhome-mixer/scorers/mod.rs+0/−1
Mhome-mixer/scorers/ranking_scorer.rs+12/−465
Dhome-mixer/scorers/value_model_gate.rs+0/−537
Mhome-mixer/side_effects/reranking_kafka_side_effect.rs+2/−3
Mhome-mixer/side_effects/scored_stats_side_effect.rs+25/−0
Mhome-mixer/sources/phoenix_moe_source.rs+1/−0
Mhome-mixer/sources/phoenix_source.rs+67/−19
Mhome-mixer/sources/phoenix_topics_source.rs+1/−0
Mphoenix/xrex/cuda/__init__.py+11/−4comments only
Mphoenix/xrex/cuda/adler32/__init__.py+21/−6
Mphoenix/xrex/cuda/top_k_by_key/__init__.py+26/−6
Mphoenix/xrex/cuda/unique/__init__.py+15/−5
Mphoenix/xrex/models/recsys_model.py+7/−21
Mphoenix/xrex/train/recsys_bundle_export.py+559/−107
Munder-the-hood/scalding/UthPctdAccountTakedownEventsJob.scala+22/−39
Munder-the-hood/strato/lib/underTheHoodLabels.strato+1/−1
Mvisibility-filtering-client/vf_client.rs+250/−0
Mvisibility-filtering/clients/socialgraph_client.rs+25/−20
Avisibility-filtering/evaluate_tweets.rs+258/−0
Mvisibility-filtering/filter.rs+336/−13
Mvisibility-filtering/filter_tweets.rs+8/−5
Mvisibility-filtering/hydration/batch.rs+49/−0
Mvisibility-filtering/hydration/exclusive_content_hydrator.rs+100/−47
Mvisibility-filtering/hydration/gizmoduck_hydrator.rs+60/−10
Mvisibility-filtering/hydration/metrics.rs+14/−0
Mvisibility-filtering/hydration/mod.rs+78/−22
Mvisibility-filtering/hydration/socialgraph_hydrator.rs+2/−2
Avisibility-filtering/hydration/tes_composite.rs+607/−0
Mvisibility-filtering/hydration/tes_hydrator.rs+113/−320
Mvisibility-filtering/hydration/viewer_hydrator.rs+30/−19
Mvisibility-filtering/lib.rs+1/−0
Mvisibility-filtering/models/exclusive_content.rs+1/−1
Mvisibility-filtering/models/tweet.rs+4/−8
Mvisibility-filtering/rules/metrics.rs+21/−19
Mvisibility-filtering/safety_label_source/lookup.rs+18/−0
Mvisibility-filtering/server.rs+86/−2
Mvisibility-filtering/server_deps.rs+18/−7