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.

Parameter history

Every change to a param! default in upstream history, newest first (the initial bulk addition of parameters on Aug 13, 2026 is listed on its entry page instead).

DateChangeParameterOldNew
Oct 8, 2026addedVideoCarouselPosition
home-mixer/params/param.rs		—6
Oct 8, 2026addedVideoCarouselFatigueMinutes
home-mixer/params/param.rs		—60
Oct 8, 2026addedEnableVideoCarousel
home-mixer/params/param.rs		—false
Oct 7, 2026changedPostUnexploredWeight
home-mixer/params/param.rs		0.020.015
Oct 7, 2026changedEnablePopularPostsSource
home-mixer/params/param.rs		falsetrue
Oct 6, 2026removedPopularPostsTopAuthors
home-mixer/params/param.rs		1000—
Oct 6, 2026removedPopularPostsMaxRepliesRepostsPerAuthor
home-mixer/params/param.rs		0—
Oct 6, 2026removedPopularPostsMaxPerAuthor
home-mixer/params/param.rs		3—
Oct 6, 2026changedVMRankerClusterId
home-mixer/params/param.rs		"Experiment6""Experiment1"
Oct 6, 2026changedRetrievalCandidatesKafkaMaxCandidates
home-mixer/params/param.rs		200100000
Oct 6, 2026addedVideoContinuationWeight
vm-ranker/params.rs		—0.0
Oct 6, 2026addedUserVideoContinuationWeight
vm-ranker/params.rs		—0.0
Oct 6, 2026addedProfileVisitSecsWeight
vm-ranker/params.rs		—0.0
Oct 6, 2026addedPostUnexploredIncludeOutOfNetwork
vm-ranker/params.rs		—false
Oct 6, 2026addedEnableUnderTheHood
home-mixer/params/param.rs		—false
Oct 6, 2026addedEnableHomeExcursionScores
home-mixer/params/param.rs		—false
Oct 3, 2026changedEnableAdsBrandSafetyVerdictV2
home-mixer/params/param.rs		falsetrue
Oct 3, 2026addedAuthorExplorationBonus
vm-ranker/params.rs		—0.0
Oct 3, 2026addedVMRankerSendPacingInputs
home-mixer/params/param.rs		—false
Oct 3, 2026addedPopularPostsTopAuthors
home-mixer/params/param.rs		—1000
Oct 3, 2026addedPopularPostsMaxResults
home-mixer/params/param.rs		—500
Oct 3, 2026addedPopularPostsMaxRepliesRepostsPerAuthor
home-mixer/params/param.rs		—0
Oct 3, 2026addedPopularPostsMaxPerAuthor
home-mixer/params/param.rs		—3
Oct 3, 2026addedEnablePopularPostsSource
home-mixer/params/param.rs		—false
Oct 3, 2026addedEnablePhoenixOonReplies
home-mixer/params/param.rs		—false
Oct 3, 2026addedEnableAdsAuthorBrandSafetyFallback
home-mixer/params/param.rs		—false
Oct 2, 2026removedTestCap
home-mixer/util/author_rules.rs		10.0—
Oct 2, 2026removedTestBoost
home-mixer/util/author_rules.rs		1.0—
Oct 2, 2026addedSidSourceMinPrefixDepth
home-mixer/params/param.rs		—3
Oct 2, 2026addedSidSourceMaxSeeds
home-mixer/params/param.rs		—50
Oct 2, 2026addedSidSourceMaxResults
home-mixer/params/param.rs		—800
Oct 2, 2026addedSidSourceMaxPerSeed
home-mixer/params/param.rs		—100
Oct 2, 2026addedEnableSidSource
home-mixer/params/param.rs		—false
Oct 1, 2026removedFeedSurveyFatigueHours
home-mixer/params/param.rs		24—
Oct 1, 2026addedFeedSurveyFatigueMinutes
home-mixer/params/param.rs		—1440
Sep 30, 2026changedPhoenixColdStartMaxResults
home-mixer/params/param.rs		0200
Sep 30, 2026changedLowImpressionsMaxPositionRatio
home-mixer/params/param.rs		0.850.97
Sep 30, 2026changedEnableColdStartThompsonSampling
home-mixer/params/param.rs		falsetrue
Sep 30, 2026changedColdStartMaxPostAgeSecs
home-mixer/params/param.rs		1728007200
Sep 30, 2026changedColdStartImpressionThreshold
home-mixer/params/param.rs		1000200
Sep 30, 2026changedColdStartFollowerCap
home-mixer/params/param.rs		100050000
Sep 29, 2026removedUseEngagementCounterViewCountForImpressionBoost
home-mixer/params/param.rs		true—
Sep 29, 2026changedNotInterestedWeight
vm-ranker/params.rs		-43.2-47.52
Sep 29, 2026changedContClickDwellTimeWeight
vm-ranker/params.rs		0.00.4
Sep 29, 2026changedClickWeight
vm-ranker/params.rs		0.40.3
Sep 29, 2026changedNotInterestedWeight
home-mixer/params/param.rs		-43.2-47.52
Sep 29, 2026changedContClickDwellTimeWeight
home-mixer/params/param.rs		0.00.4
Sep 29, 2026changedClickWeight
home-mixer/params/param.rs		0.40.3
Sep 29, 2026addedPhoenixRetrievalExcludeSeenPosts
home-mixer/params/param.rs		—false
Sep 24, 2026removed (still defined in vm-ranker/params.rs)WeightPerturbationSigma
home-mixer/params/param.rs		0.0—
Sep 24, 2026removed (still defined in vm-ranker/params.rs)WeightPerturbationSalt
home-mixer/params/param.rs		""—
Sep 24, 2026removedVMRankerSendValueModelInputs
home-mixer/params/param.rs		false—
Sep 24, 2026removedVMRankerDppTheta
home-mixer/params/param.rs		0.65—
Sep 24, 2026removedVMRankerDppMaxSelectedRank
home-mixer/params/param.rs		150—
Sep 24, 2026removedVMRankerComputeValueModel
home-mixer/params/param.rs		false—
Sep 24, 2026removed (still defined in vm-ranker/params.rs)TopicOonWeightFactor
home-mixer/params/param.rs		0.5—
Sep 24, 2026removedPostUnexploredWeightInNetworkOnly
home-mixer/params/param.rs		true—
Sep 24, 2026removed (still defined in vm-ranker/params.rs)OonWeightFactor
home-mixer/params/param.rs		0.75—
Sep 24, 2026removed (still defined in vm-ranker/params.rs)NewUserOonWeightFactor
home-mixer/params/param.rs		0.00001—
Sep 24, 2026removed (still defined in vm-ranker/params.rs)NewUserAgeThresholdSecs
home-mixer/params/param.rs		0—
Sep 24, 2026removed (still defined in vm-ranker/params.rs)MultiplierPreOffset
home-mixer/params/param.rs		false—
Sep 24, 2026removedMultiplicativePostUnexploredAlpha
home-mixer/params/param.rs		0.0—
Sep 24, 2026removedEnableVMRanker
home-mixer/params/param.rs		true—
Sep 24, 2026removed (still defined in vm-ranker/params.rs)EnableOonRescoreForInNetworkRepliesRetweets
home-mixer/params/param.rs		true—
Sep 24, 2026removedEnableMultiplicativePostUnexplored
home-mixer/params/param.rs		false—
Sep 24, 2026removedEnableCdwellOnImpr
home-mixer/params/param.rs		false—
Sep 24, 2026removed (still defined in vm-ranker/params.rs)EnableAuthorDiversity
home-mixer/params/param.rs		true—
Sep 24, 2026removedContActiveSecs5mResidualNormWeight
home-mixer/params/param.rs		0.0—
Sep 24, 2026removedCachedPostsReuseWeightedScore
home-mixer/params/param.rs		false—
Sep 24, 2026removed (still defined in vm-ranker/params.rs)AuthorDiversityFloor
home-mixer/params/param.rs		0.25—
Sep 24, 2026removed (still defined in vm-ranker/params.rs)AuthorDiversityDecay
home-mixer/params/param.rs		0.5—
Sep 24, 2026changedVMRankerClusterId
home-mixer/params/param.rs		"Experiment3""Experiment6"
Sep 23, 2026changedPhoenixRetrievalMOEInferenceClusterId
home-mixer/params/param.rs		"Experiment3Memy04""Experiment2Memy04"
Sep 23, 2026changedPhoenixMoeColdStartMaxResults
home-mixer/params/param.rs		0200
Sep 23, 2026changedPhoenixMOEMaxResults
home-mixer/params/param.rs		2000
Sep 23, 2026addedWeightPerturbationSigma
vm-ranker/params.rs		—0.0
Sep 23, 2026addedWeightPerturbationSalt
vm-ranker/params.rs		—""
Sep 23, 2026addedVqvWeight
vm-ranker/params.rs		—0.0
Sep 23, 2026addedVideoOpenWeight
vm-ranker/params.rs		—0.07
Sep 23, 2026addedTopicOonWeightFactor
vm-ranker/params.rs		—0.5
Sep 23, 2026addedShareWeight
vm-ranker/params.rs		—2.0
Sep 23, 2026addedShareViaDmWeight
vm-ranker/params.rs		—5.0
Sep 23, 2026addedShareViaCopyLinkWeight
vm-ranker/params.rs		—20.0
Sep 23, 2026addedRetweetWeight
vm-ranker/params.rs		—1.0
Sep 23, 2026addedReportWeight
vm-ranker/params.rs		—-234.0
Sep 23, 2026addedReplyWeight
vm-ranker/params.rs		—5.0
Sep 23, 2026addedQuotedVqvWeight
vm-ranker/params.rs		—0.0
Sep 23, 2026addedQuotedClickWeight
vm-ranker/params.rs		—0.05
Sep 23, 2026addedQuoteWeight
vm-ranker/params.rs		—5.0
Sep 23, 2026addedProfileClickWeight
vm-ranker/params.rs		—0.0
Sep 23, 2026addedPostUnexploredWeight
vm-ranker/params.rs		—0.02
Sep 23, 2026addedPhotoExpandWeight
vm-ranker/params.rs		—0.05
Sep 23, 2026addedOpenLinkWeight
vm-ranker/params.rs		—0.2
Sep 23, 2026addedOonWeightFactor
vm-ranker/params.rs		—0.75
Sep 23, 2026addedNotInterestedWeight
vm-ranker/params.rs		—-43.2
Sep 23, 2026addedNotDwelledWeight
vm-ranker/params.rs		—-0.02
Sep 23, 2026addedNewUserOonWeightFactor
vm-ranker/params.rs		—0.00001
Sep 23, 2026addedNewUserAgeThresholdSecs
vm-ranker/params.rs		—0
Sep 23, 2026addedMuteAuthorWeight
vm-ranker/params.rs		—-58.8
Sep 23, 2026addedMultiplierPreOffset
vm-ranker/params.rs		—false
Sep 23, 2026addedMinVideoDurationMs
vm-ranker/params.rs		—10_000
Sep 23, 2026addedFollowAuthorWeight
vm-ranker/params.rs		—4.0
Sep 23, 2026addedFavoriteWeight
vm-ranker/params.rs		—0.5
Sep 23, 2026addedEnableQuotedVqvDurationCheck
vm-ranker/params.rs		—false
Sep 23, 2026addedEnableOonRescoreForInNetworkRepliesRetweets
vm-ranker/params.rs		—true
Sep 23, 2026addedEnableAuthorDiversity
vm-ranker/params.rs		—true
Sep 23, 2026addedDwellWeight
vm-ranker/params.rs		—0.05
Sep 23, 2026addedDppTheta
vm-ranker/params.rs		—0.65
Sep 23, 2026addedDppMaxSelectedRank
vm-ranker/params.rs		—150
Sep 23, 2026addedDppEnabled
vm-ranker/params.rs		—true
Sep 23, 2026addedContDwellTimeWeight
vm-ranker/params.rs		—0.004
Sep 23, 2026addedContClickDwellTimeWeight
vm-ranker/params.rs		—0.0
Sep 23, 2026addedComputeValueModel
vm-ranker/params.rs		—false
Sep 23, 2026addedClickWeight
vm-ranker/params.rs		—0.4
Sep 23, 2026addedBlockAuthorWeight
vm-ranker/params.rs		—-31.2
Sep 23, 2026addedBidirectionalFollowReplyWeightBoost
vm-ranker/params.rs		—15.0
Sep 23, 2026addedBidirectionalFollowDwellWeightBoost
vm-ranker/params.rs		—0.0
Sep 23, 2026addedAuthorDiversityFloor
vm-ranker/params.rs		—0.25
Sep 23, 2026addedAuthorDiversityDecay
vm-ranker/params.rs		—0.5
Sep 23, 2026addedVMRankerSendDebiasInputs
home-mixer/params/param.rs		—false
Sep 23, 2026addedCachedPostsReuseWeightedScore
home-mixer/params/param.rs		—false
Sep 22, 2026addedVMRankerSendValueModelInputs
home-mixer/params/param.rs		—false
Sep 22, 2026addedVMRankerComputeValueModel
home-mixer/params/param.rs		—false
Sep 22, 2026addedSimclustersMaxCandidateAgeHours
home-mixer/params/param.rs		—48
Sep 22, 2026addedRetrievalCandidatesKafkaSamplePercent
home-mixer/params/param.rs		—5.0
Sep 22, 2026addedRetrievalCandidatesKafkaMaxCandidates
home-mixer/params/param.rs		—200
Sep 22, 2026addedPhoenixMoeColdStartMaxResults
home-mixer/params/param.rs		—0
Sep 22, 2026addedNewUserOonWeightFactor
home-mixer/params/param.rs		—0.00001
Sep 18, 2026removedValueModelMode
home-mixer/params/param.rs		"weighted"—
Sep 18, 2026removedDwellRegretTemperature
home-mixer/params/param.rs		10.0—
Sep 18, 2026removedDwellRegretNegReport
home-mixer/params/param.rs		-60000.0—
Sep 18, 2026removedDwellRegretNegNotInterested
home-mixer/params/param.rs		-10000.0—
Sep 18, 2026removedDwellRegretNegMuteAuthor
home-mixer/params/param.rs		-15000.0—
Sep 18, 2026removedDwellRegretNegBlockAuthor
home-mixer/params/param.rs		-8000.0—
Sep 18, 2026removedDwellRegretGateWeights
home-mixer/params/param.rs		"seq_len:0.530298,n_fav:-0.082139,n_reply:0.485541,n_rt_quote:0.056561,n_vqv:-0.072778,n_click:-0.176675,n_bm_share:-0.167574,n_profile_follow:-0.221285,n_photo:-0.106004,n_negfb:0.031839,n_7d:-0.075799,n_1d:-0.241730,active_days:0.047017,active_days_7d:-0.126896,days_since_last:-0.034238,span_days:-0.052186,followers:-0.066642,followings:0.064140,account_age_years:-0.045455"—
Sep 18, 2026removedDwellRegretGateThreshold
home-mixer/params/param.rs		-0.634264—
Sep 18, 2026removedDwellRegretGateHysteresisBand
home-mixer/params/param.rs		0.0—
Sep 18, 2026removedDwellRegretGateBias
home-mixer/params/param.rs		1.033918—
Sep 18, 2026removedDwellRegretDwellFloor
home-mixer/params/param.rs		1.0—
Sep 18, 2026removedDwellRegretAlphaShareViaDm
home-mixer/params/param.rs		1.0—
Sep 18, 2026removedDwellRegretAlphaShareViaCopyLink
home-mixer/params/param.rs		1.0—
Sep 18, 2026removedDwellRegretAlphaShare
home-mixer/params/param.rs		1.0—
Sep 18, 2026removedDwellRegretAlphaRetweet
home-mixer/params/param.rs		1.0—
Sep 18, 2026removedDwellRegretAlphaReply
home-mixer/params/param.rs		1.0—
Sep 18, 2026removedDwellRegretAlphaQuote
home-mixer/params/param.rs		1.0—
Sep 18, 2026removedDwellRegretAlphaFavorite
home-mixer/params/param.rs		1.0—
Sep 18, 2026changedPhoenixRetrievalMOEInferenceClusterId
home-mixer/params/param.rs		"Experiment2Memy04""Experiment3Memy04"
Sep 18, 2026addedPhoenixColdStartMaxResults
home-mixer/params/param.rs		—0
Sep 17, 2026removedEnableClickDwellLowFavRatePenalty
home-mixer/params/param.rs		false—
Sep 17, 2026removedClickDwellLowFavRatePenaltyFloor
home-mixer/params/param.rs		0.01—
Sep 17, 2026removedClickDwellLowFavRatePenaltyCap
home-mixer/params/param.rs		1.0—
Sep 17, 2026removedClickDwellLowFavRatePenaltyBaseline
home-mixer/params/param.rs		0.01—
Sep 17, 2026removedClickDwellLowFavRatePenaltyAlpha
home-mixer/params/param.rs		0.5—
Sep 17, 2026changedColdStartMaxPostAgeSecs
home-mixer/params/param.rs		86400172800
Sep 17, 2026addedEnableFavHoldout
home-mixer/params/param.rs		—false
Sep 17, 2026addedEnableCdwellOnImpr
home-mixer/params/param.rs		—false
Sep 16, 2026changedEnableAdsBrandSafetyVerdictV2
home-mixer/params/param.rs		truefalse
Sep 15, 2026addedEnableResponseDiversityStatsExperimentBucket
home-mixer/params/param.rs		—false
Sep 8, 2026changedPhoenixRetrievalMOEInferenceClusterId
home-mixer/params/param.rs		"Experiment1Fou""Experiment2Memy04"
Sep 8, 2026addedWeightPerturbationSigma
home-mixer/params/param.rs		—0.0
Sep 8, 2026addedWeightPerturbationSalt
home-mixer/params/param.rs		—""
Sep 4, 2026addedPhoenixExperimentOverrides
home-mixer/params/param.rs		—""
Sep 2, 2026changedPhoenixRetrievalAggregationType
home-mixer/params/param.rs		"DENSE_WITH_SHORT_DWELL""DENSE_WITH_LONG_DWELL"
Sep 1, 2026changedAdsBlenderType
home-mixer/params/param.rs		"partition_organic_low_risk""multi_risk"
Sep 1, 2026addedEnablePhoenixScoreStatsExperimentBucket
home-mixer/params/param.rs		—false
Aug 28, 2026addedRerankerHeadTag
home-mixer/params/param.rs		—0
Aug 25, 2026removedVMRankerValueModelId
home-mixer/params/param.rs		"dpp"—
Aug 25, 2026removedVMRankerSendHeadWeights
home-mixer/params/param.rs		false—
Aug 25, 2026removedUseServedSlateContext
home-mixer/params/param.rs		false—
Aug 25, 2026removedEnableMpnScoring
home-mixer/params/param.rs		false—
Aug 25, 2026changedVqvWeight
home-mixer/params/param.rs		0.050.0
Aug 25, 2026changedVideoOpenWeight
home-mixer/params/param.rs		0.050.07
Aug 25, 2026changedShadowTrafficPhoenixClusterRates
home-mixer/params/param.rs		vec!["Experiment6Fou:1.5".to_string()]vec![]
Aug 25, 2026changedPhoenixAggregationType
home-mixer/params/param.rs		"DENSE_WITH_SHORT_DWELL""DENSE_WITH_LONG_DWELL"
Aug 25, 2026changedEnableAdsBrandSafetyVerdictV2
home-mixer/params/param.rs		falsetrue
Aug 25, 2026changedDwellWeight
home-mixer/params/param.rs		0.00.05
Aug 25, 2026changedColdStartTsTopK
home-mixer/params/param.rs		52
Aug 25, 2026addedMultiplierPreOffset
home-mixer/params/param.rs		—false
Aug 20, 2026addedUseServedSlateContext
home-mixer/params/param.rs		—false
Aug 20, 2026addedEnableAiTrendFeedbackContext
home-mixer/params/param.rs		—false
Aug 17, 2026addedEnableAdsBrandSafetyVerdictV2
home-mixer/params/param.rs		—false
Aug 14, 2026addedEnableColdStartThompsonSampling
home-mixer/params/param.rs		—false
Aug 14, 2026addedColdStartTsTopK
home-mixer/params/param.rs		—5
Aug 14, 2026addedColdStartTrackedIds
home-mixer/params/param.rs		—""
Aug 14, 2026addedColdStartImpressionScale
home-mixer/params/param.rs		—1.0
Aug 14, 2026addedColdStartBetaBeta0
home-mixer/params/param.rs		—49.25
Aug 14, 2026addedColdStartBetaAlpha0
home-mixer/params/param.rs		—0.75