NeuroLag

Smart TPS-aware mob AI optimizer for Paper 1.21+

Protect your TPS before the lag even starts — then quietly undo everything when the server recovers.

📥 Download • 🐛 Report a Bug • 📄 Changelog

📖 Table of Contents

• ✨ Features
• 🔁 How It Works
• 📦 Requirements
• 🚀 Installation
• ⌨️ Commands & Permissions
• 🔧 Configuration
• 🌐 Web Dashboard
• 🔗 Multi-Server Sync
• 🛡️ Protected Zones
• 🗂️ Config Profiles
• 💾 Backup System
• 🧩 Developer API
• 🔍 Troubleshooting
• ❓ FAQ
• 📄 Credits

✨ Features

🧠 Intelligent TPS State Machine

NeuroLag continuously samples TPS, CPU load, heap usage, player count, and predictive trend data to decide which of three states to apply per world:

All thresholds are configurable per-world and can be overridden by config profiles. A hysteresis buffer (default 0.5 TPS) prevents oscillation at the boundary.

⚡ 31 Optimization Features

F1 — CPU Throttle Penalty

Monitors JVM CPU usage. When usage exceeds the configured threshold (default 80%), a 1.5 TPS penalty is applied to the effective TPS calculation, triggering stricter mob optimizations before the server thread becomes saturated.

F2 — Region-Based Pathfinding Cutoff

Divides each world into configurable regions. Mobs beyond the pathfinding distance threshold (disable-pathfinding-distance-chunks: 8) have their FOLLOW_RANGE attribute zeroed, eliminating expensive A* pathfinding for mobs no player will ever see.

F3 — Chunk-Based AI Toggle

Mobs outside a configurable chunk radius from any player (distance-chunks: 4) have their AI disabled entirely during CRITICAL state. Mobs within range always retain full AI regardless of server state.

F4 — Velocity Freeze

Distant AI-disabled mobs have their velocity zeroed to prevent passive drift. Configurable minimum chunk distance (freeze-distance-chunks: 6).

F5 — Spawn Suppression

During MEDIUM and CRITICAL states, monster and animal spawn limits are reduced (monster-limit: 30, animal-limit: 10) to slow mob population growth while the server is already under load.

F6 — Smart Culling

When the per-world entity count exceeds max-entities-per-world during CRITICAL state, the lowest-priority mobs are removed. Supports three culling strategies:

Protected-zone mobs and named / tamed mobs (if whitelisted) are never culled.

F7 — Tick Throttling

During MEDIUM state, non-priority mobs have their AI ticked only once every N game ticks (ticks-per-ai-tick: 4) instead of every tick. This halves or quarters AI cost without fully disabling mobs.

F8 — Mob Weight System

Each entity type is assigned a weight score. Culling prioritizes heaviest entities first. Fully configurable (zombies.yml-style block in features.yml).

F9 — AI Difficulty Scaling

Adjusts the effective TPS threshold based on world difficulty, so optimization triggers earlier on Easy (players care less) and later on Hard (players want full mob behaviour).

F10 — Memory Pressure Penalty

Monitors JVM heap usage ratio. When used heap exceeds the configured threshold (default 80%), a configurable TPS penalty is added, pre-emptively triggering optimizations before a GC pause hits.

F11 — Predictive Scheduler

Tracks historical TPS over a sliding window and a configurable set of peak hours. If a downward TPS trend is detected early (before the threshold is crossed), an earlyOffset penalty is applied to trigger optimizations proactively.

Configurable peak hours example:

peak-hours: "17:00-19:00,19:00-22:00"

F12 — Protected Zones

Mobs inside defined cuboid zones (or WorldGuard regions) are never throttled, culled, or have their attributes modified. Follow range is always restored to default when a mob is found inside a protected zone.

F13 — Smart Group Culling

Instead of culling random mobs, groups entities by type and only targets types with more than min-type-before-cull instances, preserving ecological diversity while reducing the highest-density populations.

F14 — Per-Player Action Bar Notifications

Players near affected mobs receive an action-bar warning during MEDIUM/CRITICAL states. Configurable radius (radius-blocks: 64).

F15 — Alert System

Admin action-bar broadcasts on state transitions. Optional Discord webhook and in-game sound alerts. Sound names, particle types, particle count, and whether to show an action-bar alert are all configurable in monitors.yml under alerts.*. Includes per-player cooldown to prevent sensory spam on multi-world servers.

F16 — Player-Count Scaling

TPS thresholds dynamically tighten as more players join. Configure min-players, max-players, and max-threshold-offset to have the plugin optimize more aggressively during peak player counts.

F17 — Animation Freezing

Freezes the velocity of mobs beyond freeze-distance-chunks during CRITICAL state, preventing physics drift without requiring NMS or packet-level access.

F18 — Config Auto-Backup

Automatically creates timestamped ZIP bundles of all NeuroLag YAML files (including lang/) on a configurable schedule and keeps the N most recent copies. Each backup is accompanied by a .sha256 checksum file that is verified before any restore. Protects against zip-bomb attacks with per-entry (10 MB) and total-restore (50 MB) size caps.

F19 — Safe Mode for Critical State

When enabled in the critical TPS tier configuration, Safe Mode selectively disables only dangerous AI components while preserving essential game mechanics. Prevents over-optimization that would break villager trading, mob escaping water, and other critical behaviors.

F20 — Mob Importance Scoring System

Assigns importance scores to all mobs based on type, naming, tamed status, equipment, and leash status. Named mobs (10x), tamed mobs (20x), and equipped mobs (1.5x) receive higher priority. System protects important mobs during culling operations.

F21 — Mob Behavior Groups

Categorizes mobs into behavior groups for targeted optimization:

• PASSIVE (low priority): Cows, pigs, sheep, chickens
• AGGRESSIVE (high priority): Zombies, skeletons, creepers
• NEUTRAL (medium priority): Endermen, iron golems
• SPECIAL (preserve): Villagers, bosses, named mobs
• AQUATIC (water-based): Dolphins, guardians, squids

F22 — Dynamic Region Sizing

Automatically adjusts region size based on player count for optimal performance:

• 0-5 players: 16 chunks (large regions)
• 6-20 players: 8 chunks (medium regions)
• 21-50 players: 4 chunks (small regions)
• 50+ players: 2 chunks (very small regions)

F23 — Hot Region Decay

Regions gradually cool down when players leave, preventing regions from staying hot indefinitely. Heat decays at 5% per second when no players are present.

F24 — EWMA Prediction Algorithm

Exponentially Weighted Moving Average provides better short-term TPS prediction by giving more weight to recent samples. Alpha smoothing factor of 0.3 for optimal responsiveness.

F25 — Linear Regression Trend Analysis

Detects downward TPS trends using linear regression to predict lag before it occurs. Combines with simple average and EWMA for robust prediction accuracy.

F26 — Annotation-Based Config Validation

@ConfigValidation annotation allows field-level validation rules for configuration values. Validates numeric ranges, required fields, and boundary warnings with clear error messages.

F27 — Config Migration System

Automatic version checking and stepwise migrations for config files. Creates backups before migration and supports rollback. Migrates config.yml, features.yml, monitors.yml, and systems.yml while preserving user settings.

F28 — Event-Driven Architecture

EventBus pattern decouples optimization logic from the main engine. Components can register as OptimizationListener to react to optimization state changes, enabling plugins/addons to extend functionality.

F29 — Refactored Optimizer Classes

Optimization logic extracted into dedicated classes following Single Responsibility Principle:

• MobCuller - Entity culling with importance scoring
• AIThrottler - AI throttling and tick management
• SpawnSuppressor - Spawn rate adjustment logic

F30 — Comprehensive Config Guide

CONFIG-GUIDE.md provides detailed explanations for all configuration options, including usage examples, recommended values, and troubleshooting tips organized by functional areas.

F31 — Enhanced Config Comments

All YAML configuration files (config.yml, features.yml, monitors.yml, systems.yml) include detailed inline comments, section headers, and security notes for better understanding and configuration management.

📊 Monitoring & Reporting

🔗 Multi-Server Sync

Propagates TPS state across a network in real time. Supports:

• Redis (recommended) — sub-100 ms latency via Pub/Sub
• MySQL — polling-based, works with any shared database

Cascade warnings alert local admins when a peer server enters CRITICAL state.

🗂️ Config Profiles

Switch between named configuration presets at runtime:

/nlag profile survival
/nlag profile event
/nlag profile clear

Profiles override critical-tps, medium-tps, and max-entities without touching your base config files.

🧩 Developer API

NeuroLagAPI api = NeuroLagAPI.getInstance();

api.getCurrentTps();
api.getWorldState("world");           // "NORMAL" | "MEDIUM" | "CRITICAL"
api.isManualOverride();
api.getCriticalActivationCount();
api.getMediumActivationCount();

🔁 How It Works

Every check-interval seconds (default: 10):

  Raw TPS
    │
    ├─ Memory pressure penalty  (if heap > threshold)
    ├─ CPU throttle penalty     (if CPU > threshold)
    ├─ Predictive offset        (if downward trend detected)
    └─ Difficulty scaling       (per-world adjustment)
            │
            ▼
       Effective TPS
            │
   ┌────────┴─────────┐
   │  Hysteresis FSM  │   NORMAL ↔ MEDIUM ↔ CRITICAL
   └────────┬─────────┘
            │
   ┌────────┴────────────────────────────────┐
   │  Per-world optimization pass            │
   │  • Collect targets (cached 4 ticks)     │
   │  • Spawn suppression                    │
   │  • Smart culling (if CRITICAL)          │
   │  • Batched AI/range update (≤ 50/batch) │
   │  • Admin + player notifications         │
   └─────────────────────────────────────────┘

On recovery to NORMAL:
  → restoreWorld() — full AI + default FOLLOW_RANGE for all mobs

📦 Requirements

🚀 Installation

1. Download NeuroLag-1.5.2.jar from Modrinth.

2. Place it in your plugins/ folder.

3. Start the server once to generate all config files.

4. Edit the files in plugins/NeuroLag/:

   File	Purpose
   config.yml	TPS thresholds, target rules, per-world overrides
   features.yml	Toggle and tune each optimization feature
   monitors.yml	Dashboard, web API, alerts, Discord, audit
   systems.yml	Sync, zones, profiles, backup, validator

5. Run /nlag validate to catch configuration errors.

6. Run /nlag status to confirm everything is active.

⚠️ Do not use /reload. Always do a full server restart or use /nlag reload for NeuroLag-specific changes.

⌨️ Commands

Aliases: /neurolag, /nl, /neuromob

🔐 Permissions

🔧 Configuration

NeuroLag uses a split-config layout. All files are in plugins/NeuroLag/.

config.yml — Core Settings

settings:
  language: en                # en, vi, es, fr, de, ja, zh
  check-interval: 10          # seconds between TPS samples
  enable-logging: true
  hysteresis-buffer: 0.5      # TPS gap before state recovers

tiers:
  medium:
    tps-trigger: 18.0
    range-multiplier: 0.5     # scale mob FOLLOW_RANGE to 50% in MEDIUM
  critical:
    tps-trigger: 15.0

targets:
  hostile-mobs: true
  passive-mobs: false
  water-mobs: true
  whitelist-types: [WARDEN, ELDER_GUARDIAN, ENDER_DRAGON, WITHER]
  protect-named-mobs: true
  protect-tamed-mobs: true

features.yml — Optimization Toggles

culling:
  enabled: true
  max-entities-per-world: 500
  priority: "FAR_FROM_PLAYER"   # FAR_FROM_PLAYER | GROUP | RANDOM

chunk-ai:
  enabled: true
  distance-chunks: 4

tick-throttle:
  enabled: true
  ticks-per-ai-tick: 4

spawn-suppression:
  enabled: true
  monster-limit: 30
  animal-limit: 10

cpu-throttling:
  enabled: true
  cpu-threshold: 80
  mode: THROTTLE_TASKS

memory-pressure:
  enabled: true
  percent: 0.80               # 80% heap used = apply penalty
  offset: 0.5

smart-culling:
  enabled: true
  cull-in-groups: true
  min-type-before-cull: 2
  removal-particle: POOF

monitors.yml — Dashboard & Alerts

dashboard:
  enabled: true
  type: BOSSBAR
  update-interval: 2
  bossbar:
    name: "Server Health"
    color: BLUE

web-dashboard:
  enabled: true
  port: 8080
  auth:
    token: "change-this-token-now"
    require-auth: true
    allow-query-token: false    # keep false for security

discord:
  enabled: false
  webhook-url: ""
  notify-on-critical: true
  notify-on-recovery: true

audit-reports:
  enabled: true
  generate-on: CRITICAL_EVENT
  output-format: HTML

systems.yml — Maintenance & Sync

stress-test:
  enabled: false
  max-mob-count: 2000
  cooldown-seconds: 300
  max-mobs-per-chunk: 80          # NEW 1.5.2 — crash-prevention density cap
  entity-types:
    - ZOMBIE
    - SKELETON
    - CREEPER

multi-server:
  enabled: false
  backend: REDIS              # REDIS or MYSQL

zone-protection:
  enabled: false
  integrate-worldguard: false
  zones:
    - "world 0 60 0 100 200 100"

config-profiles:
  enabled: true
  profiles:
    survival:
      critical-tps: 15.0
      medium-tps: 18.0
      max-entities: 500

auto-backup:
  enabled: true
  backup-interval-minutes: 60
  keep-backups: 10

🔒 Security (v1.5.2)

NeuroLag 1.5.2 ships with three security improvements to the web dashboard:

On first startup, if the token is still "change-this-token-now", NeuroLag automatically generates a cryptographically secure random token, saves it to monitors.yml (creating the file if needed), and prints it to the console. Use it as your Authorization: Bearer <token> header.

1.5.2 fix: Token generation now runs before the enabled check, so the placeholder is replaced even if you have web-dashboard.enabled: false. Previously, flipping the dashboard on after initial setup could expose the default token until the next restart.

🌐 Web Dashboard

The embedded HTTP server exposes a live dashboard and JSON API.

Routes:

Allowed commands via /api/cmd: reload, status, graph, validate

Authentication:

Always use the Authorization: Bearer <token> request header. The ?token=... query-string fallback is disabled by default (allow-query-token: false) because tokens in URLs appear in server access logs and browser history.

# Correct
curl -H "Authorization: Bearer my-secret-token" http://localhost:8080/api/status

# Works but insecure — only if allow-query-token: true
curl "http://localhost:8080/api/status?token=my-secret-token"

⚠️ Always change the default token and never expose the web dashboard port publicly without a reverse proxy or firewall rule.

🔗 Multi-Server Sync

Share TPS state across a network so operators can see the health of every node from one place.

Redis (recommended)

multi-server:
  enabled: true
  backend: REDIS
  cascade-warnings: true
  redis:
    host: localhost
    port: 6379
    password: ""

MySQL

multi-server:
  enabled: true
  backend: MYSQL
  mysql:
    host: localhost
    port: 3306
    database: neurolag
    user: root
    password: ""

Use /nlag sync to see live peer states:

[NeuroLag] This server: MyServer_25565
  - LobbyServer_25565  →  19.8 TPS  [NORMAL]
  - SurvivalNode_25566 →  16.2 TPS  [MEDIUM]

v1.5.1: Redis subscriber now exits cleanly on reload. MySQL reconnect uses exponential back-off to avoid log spam during DB outages.

🛡️ Protected Zones

Define cuboid zones where mobs are never optimized, throttled, or culled.

zone-protection:
  enabled: true
  integrate-worldguard: false   # set true to also protect WorldGuard regions
  zones:
    - "world 0 60 0 100 200 100"       # world minX minY minZ maxX maxY maxZ
    - "world_nether -50 0 -50 50 128 50"

Protected mobs always have:

• AI enabled
• FOLLOW_RANGE restored to Minecraft default
• Velocity unfrozen
• Immunity from smart culling

v1.5.1: FOLLOW_RANGE is now unconditionally restored for protected mobs on every optimization pass, not just when the mob happens to re-enter the zone.

🗂️ Config Profiles

Switch between named presets at runtime without editing files.

config-profiles:
  enabled: true
  profiles:
    survival:
      critical-tps: 15.0
      medium-tps: 18.0
      max-entities: 500
    event:
      critical-tps: 14.0
      medium-tps: 17.0
      max-entities: 900
    minigame:
      critical-tps: 12.0
      medium-tps: 16.0
      max-entities: 1000

/nlag profile event     — switch to event profile
/nlag profile clear     — return to base config
/nlag profile           — show all profiles + current active

💾 Backup System

Automatic backups save all NeuroLag .yml files (including lang/) as timestamped ZIP bundles.

auto-backup:
  enabled: true
  backup-interval-minutes: 60
  keep-backups: 10

Backups are stored in plugins/NeuroLag/backups/.

/nlag backup                                          — create now
/nlag backup list                                     — list all
/nlag backup restore                                  — restore latest
/nlag backup restore config-bundle-2026-04-18_12-00-00.zip

v1.6.0 security improvements:

• Each backup ZIP is accompanied by a .sha256 checksum file.
• Restore verifies the checksum before extracting; a mismatch aborts with a SEVERE log.
• Zip-bomb protection: 10 MB per-entry cap and 50 MB total-restore cap.
• Backup list is cached in memory; purgeOld() uses filename-based sort — no filesystem stat calls.

v1.5.1: The lang/ subdirectory is included in all backup bundles so custom language files are not lost on restore.

🧩 Developer API

// Get the API instance
NeuroLagAPI api = NeuroLagAPI.getInstance();

// Read current TPS and world state
double tps       = api.getCurrentTps();
String state     = api.getWorldState("world");     // "NORMAL" | "MEDIUM" | "CRITICAL"
boolean override = api.isManualOverride();

// Read lifetime counters
int critCount    = api.getCriticalActivationCount();
int medCount     = api.getMediumActivationCount();

Subscribe to state changes via the plugin-message channel neurolag.api (requires neurolag.api permission set to true on the target player).

🔍 Troubleshooting

curl -H "Authorization: Bearer your-token-here" http://localhost:8080/api/status

❓ FAQ

Does NeuroLag affect player behaviour?

No. It only modifies non-player mob AI and attribute values (FOLLOW_RANGE). Players, their items, and their abilities are never touched.

Will mobs stay frozen permanently?

No. NeuroLag always restores full AI and default attributes when the server returns to NORMAL state, when the plugin is disabled, or when /nlag toggle is used to pause monitoring.

Does it support multiple worlds?

Yes. Each world is tracked independently with its own state machine. Per-world TPS thresholds can be configured in config.yml under world-settings.

Does it support Folia?

No. NeuroLag uses the Bukkit scheduler API which is not compatible with Folia's per-region threading. Folia support is planned for a future release.

Can I use it alongside other optimization plugins?

Yes, but ensure culling and AI-disable settings do not conflict. NeuroLag is designed to coexist with plugins like Spark, ClearLag, and Chunky.

How do I know it's working?

Run /nlag status — you will see current TPS, CPU, heap, per-world states, and lifetime activation counts. Run /nlag simulate 10 to force CRITICAL state and watch mobs respond in real time.

Is the config validator mandatory?

No, but strongly recommended. Run /nlag validate after every manual config edit to catch type mismatches, out-of-range values, and missing fields before they cause runtime errors.

What happens to mobs when I do /nlag reload?

As of 1.5.1: all pending batch tasks are cancelled, restoreAll() runs (mobs get full AI back), then all services restart with the new config. No mobs are left in a restricted state.

📄 Credits

Author: Duong2012G License: Apache 2.0 Modrinth: https://modrinth.com/user/Duong2012G

Open source — contributions welcome.

📋 Changelog

See CHANGELOG.md for a full version history.

Recent highlights:

• 1.8.0 — Code audit release: 7 bugs fixed, 2 incomplete refactors completed, dead code removed. Key fixes: RegionOptimizer HOT lookup broke after dynamic resize (mobs froze next to players), pendingBatchTasks memory leak on long-running servers, AIThrottler SRP refactor fully wired, applyHotRegionDecay concurrent-modification, EventBus errors logged to System.err
• 1.7.1 — 5 targeted bug fixes: Safe Mode FOLLOW_RANGE silently overwritten every tick, NullPointerException in SafeModeOptimizer on Slime/Bat entity types, restoreAI() used a hardcoded FOLLOW_RANGE table ignoring custom attributes, HARD/EASY difficulty scaling inverted, Web Dashboard rate-limit map memory leak from scanner IPs
• 1.7.0 — Major architecture refactor: MobCuller/AIThrottler/SpawnSuppressor SRP extraction, EventBus pattern, MobImportanceScorer, MobBehaviorGroups, dynamic region sizing, EWMA+LR prediction, annotation-based config validation, config migration system
• 1.5.2 — 5 targeted bug fixes: wrong api-version in plugin.yml, web token not generated when disabled, culling count wrong with protected zones, AI update scheduler saturation, stress test crash on dense spawn areas, MySQL reconnect log spam
• 1.5.1 — 4 critical + 5 high bug fixes: task leak, mob freeze, entity scan cache, FOLLOW_RANGE restore, query-token security, Redis/MySQL stability, zone culling, lang backup
• 1.4.0 — Lifecycle overhaul, zone protection, backup bundles, web auth improvements
• 1.3.0 — Predictive scheduler, zone manager, web dashboard, multi-server sync, config profiles, backup system, developer API