Initial commit: XeroAntiCheat v1.0.7

.gitignore

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+target/
+.idea/
+.classpath
+.factorypath
+.project
+.settings/
+dependency-reduced-pom.xml

README.md

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+# XeroAntiCheat - Minecraft Anti-Cheat Plugin
+
+A lightweight, production-ready anti-cheat plugin for Paper 1.21.x (compatible with 1.20-1.22).
+
+## Overview
+
+XeroAntiCheat is designed to detect common Minecraft cheats while minimizing false positives. It features:
+
+- **17 comprehensive checks** across movement, combat, and miscellaneous categories
+- **Thread-safe architecture** with async/sync operation separation
+- **Configurable thresholds** via config.yml
+- **Violation level (VL) system** with temporal decay
+- **Punishment pipeline** (warn → kick → tempban → permban)
+- **MiniMessage support** for modern chat formatting
+- **ProtocolLib integration** (optional) for packet-level detection
+- **Automatic potion effect tracking** for accurate speed/fall detection
+- **Staff alert toggle** - staff can opt out of receiving alerts
+
+## Latest Updates (v1.0.5)
+
+### Bug Fixes
+
+- **DatabaseManager race condition** - Fixed `close()` method to be synchronized and null the connection after closing. Prevents `SQLException: database is closed` errors when async inserts race with plugin disable.
+- **PhaseCheck teleport false positives** - Added `max_distance` config (default 5.0 blocks). Movement deltas exceeding this value are now ignored (treated as teleports). Also replaced hardcoded Y-offset `0.1` with `player.getEyeHeight()` for state-aware ray-casting.
+- **Position history reset on teleport** - Added `PlayerTeleportEvent` handler in MovementListener that clears position/velocity history, resets air ticks, and clears server velocity. Prevents false positives across all inter-position checks after teleportation.
+- **VelocityCheck grace period** - Added `PlayerRespawnEvent` handler in MiscListener that clears server velocity and position history. Prevents false positives after respawn.
+- **ScaffoldCheck Signal 4 false positive** - Changed `lastPlacementYaw` initial value from `0` to `Float.NaN` as a sentinel. Signal 4 now skips on first block placement of the session to prevent false positives when yaw happens to be near 0.
+
+### Quality Improvements
+
+- **Listener bypass comments** - Added explanatory comments at `hasPermission("xac.bypass")` early-return sites in all listeners to clarify that category/per-check bypass is enforced deeper in the call stack.
+
+---
+
+## Latest Updates (v1.0.7)
+
+### Bug Fixes
+
+- **KillAura multi-target time window** - `checkMultiTarget()` was ignoring the configured time window entirely. Was counting all-time target transitions (up to 5 attacks) instead of distinct entities attacked within the window. Fixed by using parallel iterators over `attackTimestamps` and `attackedEntities` to correctly count unique targets within the last `window` milliseconds.
+- **PlayerData deque capacity mismatch** - `attackedEntities` deque was capped at 5 while `attackTimestamps` was capped at 10. After 5 attacks, deques would desync and parallel iteration would produce incorrect results. Fixed by aligning both to capacity 10.
+- **NoFall Feather Falling negative damage** - Custom enchant levels above 8 would produce negative expected damage (e.g., level 9 → multiplier -0.08), permanently disabling the check. Fixed by clamping multiplier to minimum 0.0.
+- **ScaffoldCheck allocation in hot path** - `computePlacementIntervalStdDev()` was calling `toArray()` on every block placement, allocating arrays in a performance-critical path. Fixed with zero-allocation two-pass iterator approach.
+
+---
+
+## Latest Updates (v1.0.6)
+
+### Bug Fixes
+
+- **SpiderCheck and GlideCheck cross-player pollution** - Tick counters (`spiderAirTicks`, `glideAirTicks`) were stored as instance fields on the check class, shared across ALL players. Fixed by moving counters to PlayerData for per-player state.
+- **KillAuraCheck angle NaN false negative** - `Math.acos()` was receiving unconstrained dot product values, which can produce NaN when floating-point rounding pushes values outside [-1, 1]. This silently disabled angle detection. Fixed by clamping dot product to [-1, 1] before acos.
+- **SpeedCheck rolling average implementation** - `bufferTicks` config was read but never used. Implemented actual consecutive-tick counter that flags only after speed exceeds max for N consecutive ticks.
+- **SpeedCheck latency compensation ignored actual ping** - Was using fixed config value regardless of player ping. Now scales with actual ping using formula `min(ping / 100.0 * 0.01 * pingFactor, 0.15)`, consistent with ReachCheck.
+- **PlayerData.getSecondLastPosition() allocation** - Method was calling `toArray()` on every call, allocating a temporary array in a hot path. Replaced with iterator-based access.
+
+### Config Changes
+
+- Renamed `checks.speed.latency_compensation` to `checks.speed.ping_factor` for clarity
+
+---
+
+## Latest Updates (v1.0.4)
+
+### Bug Fixes
+
+- **FastEat bypass permissions** - Fixed missing `isBypassed()` guard in MiscListener for FastEat check. Permissions `xac.bypass.fasteat` and `xac.bypass.misc` now work correctly.
+- **Bypass consistency** - Replaced `hasPermission("xac.bypass")` with `isBypassed(player)` in all 15 check classes for consistent three-tier permission checking.
+
+### ProtocolLib Integration
+
+- **Real packet listeners** - PacketListener.java completely rewritten to use actual ProtocolLib API (no more reflection-based stubs)
+- **Three packet adapters**:
+  - Movement packets (POSITION, POSITION_LOOK, LOOK) → feeds TimerCheck counters and KillAura rotation history
+  - ARM_ANIMATION → feeds AutoClickerCheck click tracking
+  - ENTITY_VELOCITY → feeds VelocityCheck knockback verification
+- **Event guard** - TimerCheck now skips event-based counter increment when ProtocolLib is active (prevents double-counting)
+- **Click guard** - CombatListener no longer adds clicks via event when ProtocolLib handles ARM_ANIMATION
+
+### New Checks
+
+- **PhaseCheck** - Detects players clipping through solid blocks using server-side ray-casting between positions. Requires 0.5+ block movement to trigger.
+- **VelocityCheck** - Detects players ignoring server-sent knockback (no-knockback hacks). Requires ProtocolLib. Compares actual horizontal displacement against expected velocity over 4 ticks.
+
+### Scaffold Improvements
+
+- **Two new detection signals**:
+  - Signal 4: Rotation lock - detects fixed yaw while side-bridging (yaw change <2° with horizontal speed >0.15)
+  - Signal 5: Placement interval variance - detects suspiciously perfect timing (stdDev <30ms at 5+ BPS)
+- Now has 5 signals total, still requires 2 to flag
+
+### SQLite Database
+
+- **DatabaseManager** - New manager for SQLite-based punishment logging
+- Punishments now logged to both flat-file (`logs/punishments.log`) and SQLite (`data.db`)
+- Configurable via `database.enabled` in config.yml (default: true)
+
+---
+
+## Latest Updates (v1.0.3)
+
+### Bug Fixes
+
+- **Granular bypass permissions now working** - Added `isBypassed(Player)` method to Check.java and guarded all direct `addViolation()` calls in CombatListener and MiscListener. The permissions `xac.bypass.reach`, `xac.bypass.killaura`, `xac.bypass.critical`, `xac.bypass.scaffold`, `xac.bypass.nofall`, and category bypasses now function correctly for all checks.
+- **TimerCheck blink detection** - Fixed bypass check to use three-tier permission hierarchy instead of only checking global `xac.bypass`.
+- **SpeedCheck Slowness calculation** - Fixed incorrect field reference: was using `getSpeedLevel()` instead of `getSlownessLevel()` for Slowness potion penalty, causing false positives for players under Slowness effect.
+- **Async file I/O** - `logPunishment()` now writes to disk on a background thread to prevent tick lag.
+
+### Quality Improvements
+
+- **Main thread Bukkit API** - Changed `startPotionRefreshTask()` from async to sync (Bukkit API should only be called from main thread).
+- **Thread-safe collections** - Changed `alertToggles` from `HashMap` to `ConcurrentHashMap` for future-proofing.
+
+### Permission System Overhaul (v1.0.2)
+
+- **Granular permission tree** - One permission per action with wildcard inheritance
+- **Per-category alerts** - Staff can receive only movement, combat, or misc alerts
+- **Per-check bypass** - Bypass specific checks (e.g., `xac.bypass.speed`)
+- **Category bypass** - Bypass entire categories (e.g., `xac.bypass.movement`)
+- **New commands**: `/xac clearviolations <player>`, `/xac verbose <player>`
+- **Verbose mode** - Per-flag debug output (disabled by default, enable with `/xac verbose <player>`)
+- Category-filtered alerts respect permissions: `xac.alerts.movement`, `xac.alerts.combat`, `xac.alerts.misc`
+
+### Bug Fixes (v1.0.2)
+
+- **NoFallCheck**: Rewrote damage detection logic - now properly calculates expected fall damage and compares against actual damage via EntityDamageEvent
+- **CriticalCheck**: Fixed physics-based crit detection - now uses velocity/fall distance instead of damage modulo (was causing 100% false positives)
+- **airTicks**: Fixed multiple checks incrementing airTicks in same tick - now only MovementListener manages airTicks, checks have their own counters
+- **Potion Effects**: Added automatic potion effect refresh task (runs every 10 ticks async) - Speed, Slowness, Levitation, Dolphins Grace, Jump Boost, Slow Falling now properly tracked
+- **Knockback**: Added knockback tracking - SpeedCheck now accounts for knockback (500ms grace after taking damage)
+- **FastEatCheck**: Fixed to track eat start time (PlayerInteractEvent) instead of consume-to-consume interval
+- **JesusCheck**: Added isSwimming() check to avoid false positives for underwater movement
+- **ReachCheck**: Ping compensation now scales dynamically with actual player ping (0.03 blocks per 100ms, capped at 0.3)
+- **TimerCheck**: Added scheduled task for blink detection (checks every 5 ticks for gaps >500ms)
+- **Alert Toggle**: Staff can now toggle alerts on/off with `/xac alerts on/off`
+- **ConfigManager**: Fixed validation to use getDouble() for max_speed
+- **Food Detection**: MiscListener now uses Paper API isEdible() instead of hardcoded switch
+
+### Architecture Improvements
+
+- Async potion effect refresh task keeps all check data up-to-date
+- Independent tick counters per check prevent false positives from shared state
+- EntityDamageEvent listener for accurate damage comparison in NoFallCheck
+- Dynamic ping compensation in ReachCheck scales with actual network conditions
+
+## Project Structure
+
+```
+/home/axel/Músicas/Java
+├── pom.xml                          # Maven build configuration
+├── src/main/
+│   ├── java/com/xeroth/xeroanticheat/
+│   │   ├── XeroAntiCheat.java        # Main plugin class
+│   │   ├── check/
+│   │   │   └── Check.java            # Abstract base class for all checks
+│   │   ├── checks/
+│   │   │   ├── movement/             # Movement-related checks
+│   │   │   │   ├── SpeedCheck.java
+│   │   │   │   ├── FlyCheck.java
+│   │   │   │   ├── JesusCheck.java
+│   │   │   │   ├── NoFallCheck.java
+│   │   │   │   ├── TimerCheck.java
+│   │   │   │   ├── SpiderCheck.java
+│   │   │   │   └── GlideCheck.java
+│   │   │   ├── combat/              # Combat-related checks
+│   │   │   │   ├── KillAuraCheck.java
+│   │   │   │   ├── ReachCheck.java
+│   │   │   │   ├── CriticalCheck.java
+│   │   │   │   └── AutoClickerCheck.java
+│   │   │   └── misc/                # Miscellaneous checks
+│   │   │       ├── FastPlaceCheck.java
+│   │   │       ├── ScaffoldCheck.java
+│   │   │       ├── FastEatCheck.java
+│   │   │       └── InventoryMoveCheck.java
+│   │   ├── manager/                 # Core managers
+│   │   │   ├── CheckManager.java
+│   │   │   ├── ConfigManager.java
+│   │   │   ├── PunishmentManager.java
+│   │   │   └── ViolationManager.java
+│   │   ├── data/
+│   │   │   └── PlayerData.java      # Per-player state storage
+│   │   ├── command/
+│   │   │   └── XACCommand.java      # Command handler
+│   │   ├── listener/                # Event listeners
+│   │   │   ├── MovementListener.java
+│   │   │   ├── CombatListener.java
+│   │   │   └── MiscListener.java
+│   │   └── protocol/
+│   │       └── PacketListener.java   # ProtocolLib integration
+│   └── resources/
+│       ├── plugin.yml               # Plugin metadata
+│       └── config.yml               # Configuration file
+└── target/
+    └── XeroAntiCheat.jar            # Built plugin
+```
+
+## Architecture
+
+### Module Interaction
+
+```
+┌─────────────────────────────────────────────────────────────┐
+│                     XeroAntiCheat (Main)                      │
+│  - onEnable(): Initialize all managers, register listeners   │
+│  - onDisable(): Cleanup, save data, cancel tasks            │
+└─────────────────────────────────────────────────────────────┘
+         │                    │                    │
+         ▼                    ▼                    ▼
+┌──────────────────┐  ┌──────────────────┐  ┌──────────────────┐
+│  ConfigManager   │  │  CheckManager    │  │  PlayerData Cache│
+│  - loadConfig()  │  │  - registerCheck│  │  - ConcurrentHM  │
+│  - getTyped()    │  │  - runCheck()   │  │  - onJoin/Quit  │
+│  - validate()    │  │  - getCheck()   │  │  - thread-safe   │
+└──────────────────┘  └──────────────────┘  └──────────────────┘
+         │                    │                    │
+         ▼                    ▼                    ▼
+┌─────────────────────────────────────────────────────────────┐
+│                    Event Listeners (Sync)                    │
+│  - MovementListener → PlayerMoveEvent                        │
+│  - CombatListener   → EntityDamageByEntityEvent              │
+│  - MiscListener     → BlockPlaceEvent, PlayerItemConsumeEvent│
+└─────────────────────────────────────────────────────────────┘
+         │                    │                    │
+         ▼                    ▼                    ▼
+┌──────────────────┐  ┌──────────────────┐  ┌──────────────────┐
+│ ViolationManager │  │ PunishmentManager │  │  ProtocolLib     │
+│  - addViolation  │  │  - evaluate()    │  │  PacketListener │
+│  - decayVL()     │  │  - punish()      │  │  - MONITOR      │
+│  - getVL()       │  │  - warn/kick/ban │  │  - hasProtocolLib│
+└──────────────────┘  └──────────────────┘  └──────────────────┘
+```
+
+### Key Design Decisions
+
+1. **Thread Safety**: PlayerData uses `ConcurrentHashMap` and `ArrayDeque` for thread-safe operations
+2. **Performance**: Movement checks only run when `hasChangedPosition()` is true
+3. **Async Operations**: VL decay, potion refresh, config validation run async
+4. **Fallback System**: Features work without ProtocolLib (reduced accuracy)
+
+## Check Descriptions
+
+### Movement Checks
+
+| Check | Detection Method |
+|-------|-----------------|
+| **SpeedCheck** | Horizontal movement exceeding max speed for player state (sprinting, sneaking, swimming, potions, ice, etc.). Uses rolling average over 5 ticks with TPS/ping compensation. |
+| **FlyCheck** | Sustained flight without elytra/creative/spectator. Tracks air ticks and ground desync between client/server. |
+| **JesusCheck** | Walking on water without Frost Walker enchantment or boat. Checks block type at feet. |
+| **NoFallCheck** | No fall damage after falling >3 blocks. Compares expected damage vs actual, accounting for Feather Falling, Slow Falling, water, honey blocks. |
+| **TimerCheck** | Packet timing anomalies: >22 packets/sec or blink (no packets >500ms then teleport). |
+| **SpiderCheck** | Climbing non-climbable blocks (non-ladder/vine/scaffolding) with upward velocity. |
+| **GlideCheck** | Elytra-like fall curve (slow Y decrease) without elytra equipped. |
+| **PhaseCheck** | Server-side ray-cast between positions. Flags if solid block intersects movement path. Requires 0.5+ block travel. |
+
+### Combat Checks
+
+| Check | Detection Method |
+|-------|-----------------|
+| **KillAuraCheck** | Three sub-checks: (1) Attack angle >100° from look direction, (2) Snap rotation >45° between attacks, (3) Multi-targeting >2 entities within 100ms. |
+| **ReachCheck** | 3D distance from player eye to entity hitbox. Default threshold 3.2 blocks (survival), 5.0 (creative), with ping compensation. |
+| **CriticalCheck** | Critical hits without airborne state. Detects crits while on ground or while sprinting (cancels sprint). Allows legitimate jump-crits. |
+| **AutoClickerCheck** | CPS tracking over 1-second window. Flags >20 CPS. Also analyzes inter-click variance - flags suspiciously perfect patterns (stdDev < 2.0). |
+| **VelocityCheck** | Compares actual horizontal displacement against server-sent ENTITY_VELOCITY. Flags if player moves <20% of expected knockback. Requires ProtocolLib. |
+
+### Miscellaneous Checks
+
+| Check | Detection Method |
+|-------|-----------------|
+| **FastPlaceCheck** | Block placement >20 blocks/sec. Uses timestamp deque for tracking. |
+| **ScaffoldCheck** | Multi-signal detection (5 signals): (1) Pitch >75° while running, (2) Placing below player, (3) No valid support face, (4) Rotation lock (yaw change <2° while moving), (5) Placement interval variance (too-perfect timing). Requires 2+ signals. |
+| **FastEatCheck** | Food consumption faster than 32 ticks (1.6 seconds). |
+| **InventoryMoveCheck** | Position change >0.1 while inventory is open. |
+
+## Violation System
+
+### VL Accumulation
+
+- Each check maintains its own violation level per player
+- `addViolation(player, checkName, weight)` increments VL
+- Default weight is 1.0, scaled by detection severity
+
+### Decay
+
+- Runs every 30 seconds (configurable)
+- Reduces each check's VL by decay_rate (default: 0.5)
+- Minimum VL is 0.0
+
+### Thresholds
+
+Configurable per check in `config.yml`:
+```yaml
+checks.<check>:
+  warn_vl: 10      # Send warning
+  kick_vl: 25      # Kick player
+  tempban_vl: 50   # Temporary ban (30 days)
+  permban_vl: 100  # Permanent ban
+```
+
+## Punishment Pipeline
+
+1. **Warning** (VL ≥ warn_vl): MiniMessage alert to player
+2. **Kick** (VL ≥ kick_vl): `player.kick()`
+3. **TempBan** (VL ≥ tempban_vl): Execute config command
+4. **PermBan** (VL ≥ permban_vl): Execute config command
+
+Commands are configurable in config.yml:
+```yaml
+punishments:
+  kick_command: "kick %player% &c[XAC] Illegal activity detected"
+  tempban_command: "tempban %player% 30d %reason%"
+  permban_command: "ban %player% %reason%"
+```
+
+All punishments logged to `plugins/XeroAntiCheat/logs/punishments.log`.
+
+## Configuration
+
+All settings in `config.yml`:
+
+### General
+- `enabled`: Enable/disable plugin
+- `debug`: Additional logging
+- `async_task_threads`: Background thread count
+
+### Violation
+- `decay_interval`: Seconds between decay (default: 30)
+- `decay_rate`: Amount to reduce VL per decay (default: 0.5)
+
+### Checks
+Each check has `enabled` and threshold settings. See `config.yml` for defaults.
+
+### Commands
+- `reload_permission`: xac.admin
+- `bypass_permission`: xac.bypass
+- `alerts_permission`: xac.alerts
+
+## Commands
+
+| Command | Permission | Description |
+|---------|------------|-------------|
+| `/xac reload` | xac.command.reload | Reload configuration |
+| `/xac status <player>` | xac.command.status | Show player's VL levels and ping |
+| `/xac punish <player> <check>` | xac.command.punish | Manually trigger punishment |
+| `/xac clearviolations <player>` | xac.command.clearviolations | Clear all VL for a player |
+| `/xac verbose <player>` | xac.command.verbose | Toggle per-flag debug output |
+| `/xac alerts [on\|off]` | xac.command.alerts | Toggle alert receiving |
+| `/xac version` | xac.command.version | Show plugin version |
+
+## Permissions
+
+### Wildcards
+- `xac.*` - All permissions (admin + bypass)
+- `xac.admin` - All commands and alerts (does NOT grant bypass)
+- `xac.bypass` - Bypass all checks
+- `xac.alerts` - Receive all alerts
+
+### Command Permissions
+- `xac.command.reload` - /xac reload
+- `xac.command.status` - /xac status
+- `xac.command.punish` - /xac punish
+- `xac.command.clearviolations` - /xac clearviolations
+- `xac.command.verbose` - /xac verbose
+- `xac.command.alerts` - /xac alerts
+- `xac.command.version` - /xac version
+
+### Category Alerts
+- `xac.alerts.movement` - Movement check alerts only
+- `xac.alerts.combat` - Combat check alerts only
+- `xac.alerts.misc` - Misc check alerts only
+
+### Bypass Permissions
+**Movement:**
+- `xac.bypass.movement` - All movement checks
+- `xac.bypass.speed`, `xac.bypass.fly`, `xac.bypass.jesus`, `xac.bypass.nofall`, `xac.bypass.timer`, `xac.bypass.spider`, `xac.bypass.glide`
+
+**Combat:**
+- `xac.bypass.combat` - All combat checks
+- `xac.bypass.killaura`, `xac.bypass.reach`, `xac.bypass.critical`, `xac.bypass.autoclicker`
+
+**Misc:**
+- `xac.bypass.misc` - All misc checks
+- `xac.bypass.fastplace`, `xac.bypass.scaffold`, `xac.bypass.fasteat`, `xac.bypass.inventorymove`
+
+### LuckPerms Example Roles
+
+```
+# Helper - read-only, sees all alerts
+/lp group helper permission set xac.command.status true
+/lp group helper permission set xac.command.alerts true
+/lp group helper permission set xac.alerts true
+
+# Junior Mod - combat alerts only
+/lp group junior-mod permission set xac.alerts.combat true
+
+# Moderator - full alerts + punish
+/lp group moderator permission set xac.alerts true
+/lp group moderator permission set xac.command.punish true
+
+# Streamer - bypass movement + combat
+/lp group streamer permission set xac.bypass.movement true
+/lp group streamer permission set xac.bypass.combat true
+
+# Build team - bypass speed/fly only
+/lp group build permission set xac.bypass.speed true
+/lp group build permission set xac.bypass.fly true
+```
+
+## Build Instructions
+
+```bash
+# Build the plugin
+mvn package
+
+# The JAR will be in target/XeroAntiCheat.jar
+```
+
+## Dependencies
+
+- **Paper API** 1.21.1-R0.1-SNAPSHOT (provided)
+- **ProtocolLib** (optional, for packet-level detection)
+
+## Performance Optimizations
+
+1. **Event Filtering**: Movement checks only run when position actually changes
+2. **Fixed-Size Data Structures**: ArrayDeque for position/click history (max 20 entries)
+3. **Primitive Math**: Avoid creating new Location/Vector objects in hot paths
+4. **TPS Compensation**: Velocity thresholds scale with server TPS
+5. **Async Operations**: VL decay, config validation, logging run on background threads
+
+## Edge Case Handling
+
+| Scenario | Handling |
+|----------|----------|
+| Creative mode | Most checks ignored |
+| Bypass permission | Silently ignored |
+| Lag spikes | TPS compensation applied |
+| Pearl teleportation | Reset air timers, position buffers |
+| Jump-crits | Allow if wasAirborne previous 3 ticks |
+| Frost Walker | Allow water walking |
+| Slow Falling potion | Ignore fall damage |
+| Water/honey landing | No damage expected |
+
+## Future Enhancements
+
+Potential areas for expansion:
+- Entity prediction check
+- More scaffold signals
+- Velocity verification
+- Phase detection
+- Packet order validation
+- SQL-based violation logging
+- Web dashboard integration

pom.xml

@@ -0,0 +1,98 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.xeroth</groupId>
+    <artifactId>xeroanticheat</artifactId>
+    <version>1.0.7</version>
+    <packaging>jar</packaging>
+
+    <name>XeroAntiCheat</name>
+    <description>Lightweight, accurate anti-cheat for Paper 1.21.x</description>
+
+    <properties>
+        <maven.compiler.source>21</maven.compiler.source>
+        <maven.compiler.target>21</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <repositories>
+        <repository>
+            <id>papermc</id>
+            <url>https://repo.papermc.io/repository/maven-public/</url>
+        </repository>
+        <repository>
+            <id>dmulloy2-repo</id>
+            <url>https://repo.dmulloy2.net/repository/public/</url>
+        </repository>
+    </repositories>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.papermc.paper</groupId>
+            <artifactId>paper-api</artifactId>
+            <version>1.21.1-R0.1-SNAPSHOT</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.comphenix.protocol</groupId>
+            <artifactId>ProtocolLib</artifactId>
+            <version>5.3.0</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.xerial</groupId>
+            <artifactId>sqlite-jdbc</artifactId>
+            <version>3.47.1.0</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>${project.name}</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.13.0</version>
+                <configuration>
+                    <source>21</source>
+                    <target>21</target>
+                    <encoding>UTF-8</encoding>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>3.6.0</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <relocations>
+                                <relocation>
+                                    <pattern>net.kyori.adventure</pattern>
+                                    <shadedPattern>com.xeroth.xeroanticheat.adventure</shadedPattern>
+                                </relocation>
+                                <relocation>
+                                    <pattern>org.sqlite</pattern>
+                                    <shadedPattern>com.xeroth.xeroanticheat.sqlite</shadedPattern>
+                                </relocation>
+                            </relocations>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

src/main/java/com/xeroth/xeroanticheat/XeroAntiCheat.java

@@ -0,0 +1,283 @@
+package com.xeroth.xeroanticheat;
+
+import com.xeroth.xeroanticheat.checks.combat.*;
+import com.xeroth.xeroanticheat.checks.misc.*;
+import com.xeroth.xeroanticheat.checks.movement.*;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.command.XACCommand;
+import com.xeroth.xeroanticheat.listener.CombatListener;
+import com.xeroth.xeroanticheat.listener.MiscListener;
+import com.xeroth.xeroanticheat.listener.MovementListener;
+import com.xeroth.xeroanticheat.manager.CheckManager;
+import com.xeroth.xeroanticheat.manager.ConfigManager;
+import com.xeroth.xeroanticheat.manager.DatabaseManager;
+import com.xeroth.xeroanticheat.manager.PunishmentManager;
+import com.xeroth.xeroanticheat.manager.ViolationManager;
+import com.xeroth.xeroanticheat.protocol.PacketListener;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.potion.PotionEffectType;
+import org.bukkit.plugin.java.JavaPlugin;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * XeroAntiCheat - Lightweight, accurate anti-cheat for Paper 1.21.x
+ * 
+ * This plugin provides comprehensive cheat detection including movement,
+ * combat, and miscellaneous checks with minimal false positives.
+ */
+public final class XeroAntiCheat extends JavaPlugin {
+
+    private static XeroAntiCheat instance;
+    
+    private ConfigManager configManager;
+    private ViolationManager violationManager;
+    private PunishmentManager punishmentManager;
+    private CheckManager checkManager;
+    private PacketListener packetListener;
+    private DatabaseManager databaseManager;
+    
+    private boolean protocolLibLoaded = false;
+    
+    // Staff alert toggles
+    private final Map<UUID, Boolean> alertToggles = new ConcurrentHashMap<>();
+
+    // Verbose targets (per-player debug output)
+    private final Set<UUID> verboseTargets = ConcurrentHashMap.newKeySet();
+
+    @Override
+    public void onEnable() {
+        instance = this;
+        
+        // Check for ProtocolLib
+        checkProtocolLib();
+        
+        // Initialize managers
+        initializeManagers();
+        
+        // Register listeners
+        registerListeners();
+        
+        // Register commands
+        registerCommands();
+        
+        // Register checks
+        registerChecks();
+        
+        // Start decay task
+        startDecayTask();
+        
+        // Start potion effect refresh task
+        startPotionRefreshTask();
+        
+        // Start TimerCheck blink detection task
+        startTimerBlinkTask();
+        
+        getLogger().info("XeroAntiCheat v" + getDescription().getVersion() + " enabled!");
+        if (protocolLibLoaded) {
+            getLogger().info("ProtocolLib detected - packet-level checks enabled");
+        } else {
+            getLogger().info("ProtocolLib not found - using event-based detection");
+        }
+    }
+
+    @Override
+    public void onDisable() {
+        // Cancel all tasks
+        Bukkit.getScheduler().cancelTasks(this);
+        
+        // Save any pending data
+        if (violationManager != null) {
+            violationManager.saveAll();
+        }
+        
+        // Close database
+        if (databaseManager != null) {
+            databaseManager.close();
+        }
+        
+        getLogger().info("XeroAntiCheat disabled!");
+    }
+
+    private void checkProtocolLib() {
+        try {
+            Class.forName("com.comphenix.protocol.ProtocolLibrary");
+            protocolLibLoaded = true;
+        } catch (ClassNotFoundException e) {
+            protocolLibLoaded = false;
+        }
+    }
+
+    private void initializeManagers() {
+        configManager = new ConfigManager(this);
+        configManager.loadConfig();
+        
+        violationManager = new ViolationManager(this);
+        punishmentManager = new PunishmentManager(this, violationManager);
+        checkManager = new CheckManager(this);
+        
+        databaseManager = new DatabaseManager(this);
+        databaseManager.initialize();
+    }
+
+    private void registerListeners() {
+        getServer().getPluginManager().registerEvents(new MovementListener(this), this);
+        getServer().getPluginManager().registerEvents(new CombatListener(this), this);
+        getServer().getPluginManager().registerEvents(new MiscListener(this), this);
+        
+        if (protocolLibLoaded) {
+            packetListener = new PacketListener(this);
+            packetListener.register();
+        }
+    }
+
+    private void registerCommands() {
+        getCommand("xac").setExecutor(new XACCommand(this));
+    }
+
+    private void registerChecks() {
+        // Movement checks
+        checkManager.registerCheck(new SpeedCheck(this));
+        checkManager.registerCheck(new FlyCheck(this));
+        checkManager.registerCheck(new JesusCheck(this));
+        checkManager.registerCheck(new NoFallCheck(this));
+        checkManager.registerCheck(new TimerCheck(this));
+        checkManager.registerCheck(new SpiderCheck(this));
+        checkManager.registerCheck(new GlideCheck(this));
+        checkManager.registerCheck(new PhaseCheck(this));
+        
+        // Combat checks
+        checkManager.registerCheck(new KillAuraCheck(this));
+        checkManager.registerCheck(new ReachCheck(this));
+        checkManager.registerCheck(new CriticalCheck(this));
+        checkManager.registerCheck(new AutoClickerCheck(this));
+        
+        // VelocityCheck requires ProtocolLib
+        if (protocolLibLoaded) {
+            checkManager.registerCheck(new VelocityCheck(this));
+        }
+        
+        // Misc checks
+        checkManager.registerCheck(new FastPlaceCheck(this));
+        checkManager.registerCheck(new ScaffoldCheck(this));
+        checkManager.registerCheck(new FastEatCheck(this));
+        checkManager.registerCheck(new InventoryMoveCheck(this));
+        
+        getLogger().info("Registered " + checkManager.getRegisteredChecks().size() + " checks");
+    }
+
+    private void startDecayTask() {
+        int interval = configManager.getInt("violation.decay_interval", 30) * 20;
+        Bukkit.getScheduler().runTaskTimerAsynchronously(this, () -> {
+            violationManager.decayAll();
+        }, interval, interval);
+    }
+
+    private void startPotionRefreshTask() {
+        Bukkit.getScheduler().runTaskTimer(this, () -> {
+            for (Player player : Bukkit.getOnlinePlayers()) {
+                PlayerData data = violationManager.getPlayerData(player);
+                if (data == null) continue;
+
+                data.setHasSpeedEffect(player.hasPotionEffect(PotionEffectType.SPEED));
+                data.setHasSlownessEffect(player.hasPotionEffect(PotionEffectType.SLOWNESS));
+                data.setHasLevitation(player.hasPotionEffect(PotionEffectType.LEVITATION));
+                data.setHasDolphinsGrace(player.hasPotionEffect(PotionEffectType.DOLPHINS_GRACE));
+                data.setHasJumpBoost(player.hasPotionEffect(PotionEffectType.JUMP_BOOST));
+                data.setHasSlowFalling(player.hasPotionEffect(PotionEffectType.SLOW_FALLING));
+
+                var speed = player.getPotionEffect(PotionEffectType.SPEED);
+                data.setSpeedLevel(speed != null ? speed.getAmplifier() + 1 : 0);
+
+                var slowness = player.getPotionEffect(PotionEffectType.SLOWNESS);
+                data.setSlownessLevel(slowness != null ? slowness.getAmplifier() + 1 : 0);
+
+                var jump = player.getPotionEffect(PotionEffectType.JUMP_BOOST);
+                data.setJumpBoostLevel(jump != null ? jump.getAmplifier() + 1 : 0);
+            }
+        }, 10L, 10L);
+    }
+
+    private void startTimerBlinkTask() {
+        Bukkit.getScheduler().runTaskTimer(this, () -> {
+            long now = System.currentTimeMillis();
+            long threshold = configManager.getInt("checks.timer.blink_threshold_ms", 500);
+            Check timerCheck = checkManager.getCheck("Timer");
+
+            for (Player player : Bukkit.getOnlinePlayers()) {
+                if (timerCheck != null && timerCheck.isBypassed(player)) continue;
+                PlayerData data = violationManager.getPlayerData(player);
+                if (data == null || data.getLastMovePacketTime() == 0) continue;
+
+                long gap = now - data.getLastMovePacketTime();
+                if (gap > threshold) {
+                    violationManager.addViolation(player, "Timer", 2.0);
+                    punishmentManager.evaluate(player, "Timer");
+                    data.setLastMovePacketTime(now);
+                }
+            }
+        }, 5L, 5L);
+    }
+
+    /**
+     * Reload the plugin configuration and re-register checks
+     */
+    public void reload() {
+        configManager.loadConfig();
+        violationManager.clearAll();
+        getLogger().info("Configuration reloaded!");
+    }
+
+    // Getters
+    public static XeroAntiCheat getInstance() {
+        return instance;
+    }
+
+    public ConfigManager getConfigManager() {
+        return configManager;
+    }
+
+    public ViolationManager getViolationManager() {
+        return violationManager;
+    }
+
+    public PunishmentManager getPunishmentManager() {
+        return punishmentManager;
+    }
+
+    public CheckManager getCheckManager() {
+        return checkManager;
+    }
+
+    public DatabaseManager getDatabaseManager() {
+        return databaseManager;
+    }
+
+    public boolean isProtocolLibLoaded() {
+        return protocolLibLoaded;
+    }
+
+    public boolean isAlertsEnabled(java.util.UUID uuid) {
+        return alertToggles.getOrDefault(uuid, true);
+    }
+
+    public void setAlertsEnabled(java.util.UUID uuid, boolean enabled) {
+        alertToggles.put(uuid, enabled);
+    }
+
+    public boolean isVerboseTarget(UUID uuid) {
+        return verboseTargets.contains(uuid);
+    }
+
+    public void toggleVerboseTarget(UUID uuid) {
+        if (!verboseTargets.remove(uuid)) {
+            verboseTargets.add(uuid);
+        }
+    }
+}

src/main/java/com/xeroth/xeroanticheat/check/Check.java

@@ -0,0 +1,128 @@
+package com.xeroth.xeroanticheat.check;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+/**
+ * Abstract base class for all anti-cheat checks.
+ * All checks must extend this class and implement the check logic.
+ */
+public abstract class Check {
+
+    protected final XeroAntiCheat plugin;
+    protected final String name;
+    protected final String configPath;
+    
+    private boolean enabled;
+
+    public Check(XeroAntiCheat plugin, String name) {
+        this.plugin = plugin;
+        this.name = name;
+        this.configPath = "checks." + name.toLowerCase() + ".";
+        this.enabled = true;
+    }
+
+    /**
+     * Execute the check logic.
+     * 
+     * @param data Player data for the player being checked
+     * @param player The player being checked
+     */
+    public abstract void check(PlayerData data, Player player);
+
+    /**
+     * Called when the check detects a violation.
+     * 
+     * @param data Player data
+     * @param player The player
+     * @param weight Violation weight to add
+     */
+    protected void flag(PlayerData data, Player player, double weight) {
+        if (!isEnabled()) return;
+
+        if (player.hasPermission("xac.bypass")) return;
+        if (player.hasPermission("xac.bypass." + getCategory())) return;
+        if (player.hasPermission("xac.bypass." + name.toLowerCase())) return;
+
+        plugin.getViolationManager().addViolation(player, name, weight);
+        plugin.getPunishmentManager().evaluate(player, name);
+    }
+
+    /**
+     * Simplified flag with default weight
+     */
+    protected void flag(PlayerData data, Player player) {
+        flag(data, player, 1.0);
+    }
+
+    /**
+     * Get the check name
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * Check if this check is enabled
+     */
+    public boolean isEnabled() {
+        return enabled && plugin.getConfigManager().getBoolean(configPath + "enabled", true);
+    }
+
+    /**
+     * Set enabled state
+     */
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+
+    /**
+     * Get a configuration value
+     */
+    protected boolean getConfigBoolean(String key, boolean defaultValue) {
+        return plugin.getConfigManager().getBoolean(configPath + key, defaultValue);
+    }
+
+    /**
+     * Get a configuration value
+     */
+    protected int getConfigInt(String key, int defaultValue) {
+        return plugin.getConfigManager().getInt(configPath + key, defaultValue);
+    }
+
+    /**
+     * Get a configuration value
+     */
+    protected double getConfigDouble(String key, double defaultValue) {
+        return plugin.getConfigManager().getDouble(configPath + key, defaultValue);
+    }
+
+    /**
+     * Get a configuration value
+     */
+    protected String getConfigString(String key, String defaultValue) {
+        return plugin.getConfigManager().getString(configPath + key, defaultValue);
+    }
+
+    public String getCategory() {
+        String pkg = getClass().getPackageName();
+        if (pkg.endsWith("movement")) return "movement";
+        if (pkg.endsWith("combat")) return "combat";
+        return "misc";
+    }
+
+    /**
+     * Returns true if the given player should be exempt from this check,
+     * based on the three-tier bypass permission hierarchy:
+     * xac.bypass → xac.bypass.<category> → xac.bypass.<checkname>
+     *
+     * @param player The player to test
+     * @return true if the player has any applicable bypass permission
+     */
+    public boolean isBypassed(Player player) {
+        return player.hasPermission("xac.bypass")
+            || player.hasPermission("xac.bypass." + getCategory())
+            || player.hasPermission("xac.bypass." + name.toLowerCase());
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/combat/AutoClickerCheck.java

@@ -0,0 +1,90 @@
+package com.xeroth.xeroanticheat.checks.combat;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * AutoClickerCheck - Tracks CPS (clicks per second) over a 1-second sliding window.
+ * 
+ * Flags if CPS > configurable threshold (default: 20 CPS).
+ * Also analyzes inter-click intervals - legitimate humans show variance.
+ * Flags if variance is suspiciously low (jitter hack / butterfly click pattern).
+ */
+public class AutoClickerCheck extends Check {
+
+    public AutoClickerCheck(XeroAntiCheat plugin) {
+        super(plugin, "AutoClicker");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Get thresholds
+        int maxCPS = getConfigInt("max_cps", 20);
+        double minVariance = getConfigDouble("min_variance", 2.0);
+        
+        // Get CPS
+        int cps = data.getCPS();
+        
+        // Check CPS threshold
+        if (cps > maxCPS) {
+            flag(data, player, (cps - maxCPS) * 0.5);
+        }
+        
+        // Check for pattern (low variance = suspicious)
+        checkPattern(data, player, minVariance);
+    }
+    
+    /**
+     * Check click pattern for suspiciously low variance
+     */
+    private void checkPattern(PlayerData data, Player player, double minVariance) {
+        List<Long> clicks = new ArrayList<>(data.getClickTimestamps());
+        
+        if (clicks.size() < 5) return;
+        
+        // Calculate intervals between clicks
+        List<Long> intervals = new ArrayList<>();
+        for (int i = 0; i < clicks.size() - 1; i++) {
+            intervals.add(clicks.get(i) - clicks.get(i + 1));
+        }
+        
+        if (intervals.isEmpty()) return;
+        
+        // Calculate mean
+        double sum = 0;
+        for (Long interval : intervals) {
+            sum += interval;
+        }
+        double mean = sum / intervals.size();
+        
+        // Calculate variance
+        double varianceSum = 0;
+        for (Long interval : intervals) {
+            double diff = interval - mean;
+            varianceSum += diff * diff;
+        }
+        double variance = varianceSum / intervals.size();
+        double stdDev = Math.sqrt(variance);
+        
+        // If variance is too low, flag (too perfect)
+        if (stdDev < minVariance && data.getCPS() > 10) {
+            flag(data, player, 1.0);
+        }
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/combat/CriticalCheck.java

@@ -0,0 +1,67 @@
+package com.xeroth.xeroanticheat.checks.combat;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+/**
+ * CriticalCheck - Detects critical hits when player is NOT in the air.
+ * 
+ * Also detects if player is sprinting (criticals cancel sprint).
+ * Accounts for jump-crits (legitimate): allows if player was airborne in previous 3 ticks.
+ */
+public class CriticalCheck extends Check {
+
+    public CriticalCheck(XeroAntiCheat plugin) {
+        super(plugin, "Critical");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+    }
+    
+    /**
+     * Check if a critical hit is valid
+     * @param player The player
+     * @param data Player data
+     * @param isCritical Whether the hit was critical
+     * @return true if the critical is suspicious
+     */
+    public boolean checkCritical(Player player, PlayerData data, boolean isCritical) {
+        if (!isCritical) return false;
+        
+        boolean allowJumpCrits = getConfigBoolean("allow_jump_crits", true);
+        
+        // Get player state
+        boolean isOnGround = player.isOnGround();
+        double yVelocity = player.getVelocity().getY();
+        boolean wasAirborne = data.wasAirborne();
+        
+        // If player is on ground and not moving up (no jump), flag
+        if (isOnGround && yVelocity <= 0.0) {
+            // Check if was recently airborne (jump-crit)
+            if (allowJumpCrits && wasAirborne) {
+                return false; // Legitimate jump-crit
+            }
+            return true; // Suspicious - no-air crit
+        }
+        
+        // Check if sprinting (criticals cancel sprint)
+        if (player.isSprinting()) {
+            return true; // Suspicious - crit while sprinting
+        }
+        
+        return false;
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/combat/KillAuraCheck.java

@@ -0,0 +1,90 @@
+package com.xeroth.xeroanticheat.checks.combat;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.EntityEffect;
+import org.bukkit.Location;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+import org.bukkit.util.Vector;
+
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Set;
+import java.util.UUID;
+
+/**
+ * KillAuraCheck - Detects attacks on entities outside realistic FOV, snap rotations,
+ * and multi-targeting within a single tick.
+ * 
+ * Uses angle computation between player's look vector and entity vector.
+ */
+public class KillAuraCheck extends Check {
+
+    public KillAuraCheck(XeroAntiCheat plugin) {
+        super(plugin, "KillAura");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Note: Rotation analysis moved to CombatListener.onEntityDamageByEntity()
+        // This method is kept for potential future use
+    }
+    
+    /**
+     * Check angle between player look direction and entity
+     */
+    public boolean checkAngle(Player player, Entity target) {
+        if (!isEnabled()) return false;
+        
+        Location playerLoc = player.getLocation();
+        Vector playerDirection = playerLoc.getDirection();
+        
+        Vector toTarget = target.getLocation().toVector().subtract(playerLoc.toVector()).normalize();
+        
+        double dot = Math.max(-1.0, Math.min(1.0, playerDirection.dot(toTarget)));
+        double angle = Math.toDegrees(Math.acos(dot));
+        
+        double maxAngle = getConfigDouble("max_angle", 100);
+        return angle > maxAngle;
+    }
+    
+    /**
+     * Check for multi-targeting
+     */
+    public boolean checkMultiTarget(PlayerData data, Player player, Entity target) {
+        if (!isEnabled()) return false;
+        
+        long now = System.currentTimeMillis();
+        long window = (long) getConfigDouble("multitarget_window_ms", 100);
+        
+        data.addAttack(target.getUniqueId());
+
+        Set<UUID> uniqueInWindow = new HashSet<>();
+        Iterator<Long> timeIter = data.getAttackTimestamps().iterator();
+        Iterator<UUID> entityIter = data.getAttackedEntities().iterator();
+
+        while (timeIter.hasNext() && entityIter.hasNext()) {
+            long timestamp = timeIter.next();
+            UUID entityId = entityIter.next();
+
+            if (now - timestamp > window) break;
+
+            uniqueInWindow.add(entityId);
+        }
+
+        return uniqueInWindow.size() > 2;
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/combat/ReachCheck.java

@@ -0,0 +1,71 @@
+package com.xeroth.xeroanticheat.checks.combat;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.Location;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+
+/**
+ * ReachCheck - Computes 3D distance between player's eye position and 
+ * attacked entity's hitbox at attack time.
+ * 
+ * Default threshold: 3.2 blocks (creative: 5.0). Adds ping compensation.
+ */
+public class ReachCheck extends Check {
+
+    public ReachCheck(XeroAntiCheat plugin) {
+        super(plugin, "Reach");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+    }
+    
+    /**
+     * Check reach distance to a target entity
+     */
+    public boolean checkReach(Player player, Entity target) {
+        if (!isEnabled()) return false;
+        
+        // Get thresholds
+        double maxReach = getConfigDouble("max_reach", 3.2);
+        double creativeMaxReach = getConfigDouble("creative_max_reach", 5.0);
+        double pingFactor = getConfigDouble("ping_factor", 1.0);
+        
+        // Adjust for creative mode
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE) {
+            maxReach = creativeMaxReach;
+        }
+        
+        // Add ping compensation (0.03 blocks per 100ms of ping, capped at 0.3)
+        int ping = player.getPing();
+        double pingComp = Math.min(ping / 100.0 * 0.03 * pingFactor, 0.3);
+        maxReach += pingComp;
+        
+        // Add small leniency
+        maxReach += 0.3;
+        
+        // Get player eye location
+        Location eyeLoc = player.getEyeLocation();
+        
+        // Get target location (center of entity hitbox)
+        Location targetLoc = target.getLocation();
+        
+        // Calculate 3D distance
+        double distance = eyeLoc.distance(targetLoc);
+        
+        return distance > maxReach;
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/combat/VelocityCheck.java

@@ -0,0 +1,61 @@
+package com.xeroth.xeroanticheat.checks.combat;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+import org.bukkit.util.Vector;
+
+/**
+ * VelocityCheck - Detects players ignoring server-sent knockback velocity.
+ *
+ * Requires ProtocolLib. Listens for ENTITY_VELOCITY packets sent to the player,
+ * stores the expected velocity vector, then verifies that the player's actual
+ * movement on the following ticks reflects that velocity. Players using
+ * no-knockback hacks will show near-zero displacement after receiving a
+ * significant velocity packet.
+ */
+public class VelocityCheck extends Check {
+
+    public VelocityCheck(XeroAntiCheat plugin) {
+        super(plugin, "Velocity");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        if (!plugin.isProtocolLibLoaded()) return;
+
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE
+                || player.getGameMode() == org.bukkit.GameMode.SPECTATOR) return;
+
+        if (isBypassed(player)) return;
+
+        Vector expected = data.getLastServerVelocity();
+        if (expected == null || data.getVelocityCheckTicks() <= 0) return;
+
+        data.decrementVelocityCheckTicks();
+
+        double expectedHorizontal = Math.sqrt(
+                expected.getX() * expected.getX() + expected.getZ() * expected.getZ());
+
+        double minExpected = getConfigDouble("min_expected_velocity", 0.15);
+        if (expectedHorizontal < minExpected) {
+            data.clearServerVelocity();
+            return;
+        }
+
+        PlayerData.PositionSnapshot curr = data.getLastPosition();
+        PlayerData.PositionSnapshot prev = data.getSecondLastPosition();
+        if (curr == null || prev == null) return;
+
+        double actualHorizontal = Math.sqrt(
+                Math.pow(curr.x() - prev.x(), 2) + Math.pow(curr.z() - prev.z(), 2));
+
+        double ratio = getConfigDouble("min_displacement_ratio", 0.2);
+        if (actualHorizontal < expectedHorizontal * ratio) {
+            flag(data, player, 2.0);
+            data.clearServerVelocity();
+        }
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/misc/FastEatCheck.java

@@ -0,0 +1,56 @@
+package com.xeroth.xeroanticheat.checks.misc;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+/**
+ * FastEatCheck - Detects food consumption faster than the standard 1.61-second eating duration.
+ * 
+ * Standard eat time is 32 ticks (1.6 seconds).
+ * Tracks item use start time via PlayerItemConsumeEvent.
+ */
+public class FastEatCheck extends Check {
+
+    public FastEatCheck(XeroAntiCheat plugin) {
+        super(plugin, "FastEat");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+    }
+    
+    /**
+     * Check if eating is too fast
+     * @param player The player
+     * @param data Player data
+     * @param consumeTime Time of consumption
+     * @return true if eating too fast
+     */
+    public boolean checkFastEat(Player player, PlayerData data, long consumeTime) {
+        if (!isEnabled()) return false;
+        
+        long startedEating = data.getLastStartedEatingTime();
+        if (startedEating <= 0) return false;
+        
+        int maxEatTicks = getConfigInt("max_eat_ticks", 32);
+        long minMs = (long) maxEatTicks * 50;
+        
+        long elapsed = consumeTime - startedEating;
+        
+        data.setLastStartedEatingTime(0);
+        
+        return elapsed < minMs;
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/misc/FastPlaceCheck.java

@@ -0,0 +1,41 @@
+package com.xeroth.xeroanticheat.checks.misc;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+/**
+ * FastPlaceCheck - Detects block placement faster than 1 block per tick (>20 blocks/second).
+ * 
+ * Uses a timestamp deque; flags if N blocks placed within M milliseconds.
+ */
+public class FastPlaceCheck extends Check {
+
+    public FastPlaceCheck(XeroAntiCheat plugin) {
+        super(plugin, "FastPlace");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative mode
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Get threshold
+        int maxBlocksPerSecond = getConfigInt("max_blocks_per_second", 20);
+        
+        // Get blocks per second
+        int bps = data.getBlocksPerSecond();
+        
+        if (bps > maxBlocksPerSecond) {
+            flag(data, player, (bps - maxBlocksPerSecond) * 0.5);
+        }
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/misc/InventoryMoveCheck.java

@@ -0,0 +1,53 @@
+package com.xeroth.xeroanticheat.checks.misc;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+/**
+ * InventoryMoveCheck - Detects player movement while an inventory is open.
+ * 
+ * Uses InventoryOpenEvent / InventoryCloseEvent to track state.
+ * Flags significant position change while inventory is open.
+ */
+public class InventoryMoveCheck extends Check {
+
+    public InventoryMoveCheck(XeroAntiCheat plugin) {
+        super(plugin, "InventoryMove");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Only check if inventory is open
+        if (!data.isInventoryOpen()) return;
+        
+        // Get position history
+        PlayerData.PositionSnapshot current = data.getLastPosition();
+        PlayerData.PositionSnapshot last = data.getSecondLastPosition();
+        
+        if (current == null || last == null) return;
+        
+        // Calculate position change
+        double dx = current.x() - last.x();
+        double dy = current.y() - last.y();
+        double dz = current.z() - last.z();
+        double distance = Math.sqrt(dx*dx + dy*dy + dz*dz);
+        
+        // If significant movement while inventory open, flag
+        if (distance > 0.1) {
+            flag(data, player);
+        }
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/misc/ScaffoldCheck.java

@@ -0,0 +1,177 @@
+package com.xeroth.xeroanticheat.checks.misc;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.block.Block;
+import org.bukkit.entity.Player;
+
+import java.util.Deque;
+
+/**
+ * ScaffoldCheck - Detects suspicious block placement patterns characteristic of scaffold hacks.
+ *
+ * Combines signals:
+ * 1. Placing blocks behind/below while moving forward
+ * 2. Placing blocks with pitch angle >75° (looking almost straight down)
+ * 3. Placing blocks without valid adjacent support face
+ * 4. Rotation lock (yaw barely changes while side-bridging)
+ * 5. Placement interval variance (too-perfect timing)
+ *
+ * Requires at least 2 signals to flag.
+ */
+public class ScaffoldCheck extends Check {
+
+    public ScaffoldCheck(XeroAntiCheat plugin) {
+        super(plugin, "Scaffold");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Reset signals periodically
+        if (data.getScaffoldSignals() > 10) {
+            data.resetScaffoldSignals();
+        }
+    }
+    
+    /**
+     * Check scaffold signals for a block placement
+     * @param player The player
+     * @param blockPlaced The block that was placed
+     * @param data Player data
+     * @return true if scaffold is detected
+     */
+    public boolean checkScaffold(Player player, Block blockPlaced, PlayerData data) {
+        if (!isEnabled()) return false;
+        
+        int signalsRequired = getConfigInt("signals_required", 2);
+        int signalCount = 0;
+        
+        // Signal 1: Pitch check - looking down while placing
+        float pitch = player.getLocation().getPitch();
+        int minPitch = getConfigInt("min_pitch", 75);
+        if (pitch > minPitch) {
+            signalCount++;
+        }
+        
+        // Signal 2: Position check - placing below/behind player
+        Location playerLoc = player.getLocation();
+        Location blockLoc = blockPlaced.getLocation();
+        
+        double dx = blockLoc.getX() - playerLoc.getX();
+        double dy = blockLoc.getY() - playerLoc.getY();
+        double dz = blockLoc.getZ() - playerLoc.getZ();
+        
+        // If placing below
+        if (dy < -0.5) {
+            signalCount++;
+        }
+        
+        // Signal 3: No valid support face
+        boolean hasSupport = hasValidSupport(blockPlaced);
+        if (!hasSupport) {
+            signalCount++;
+        }
+
+        // Signal 4: Rotation lock
+        float currentYaw = player.getLocation().getYaw();
+
+        if (!Float.isNaN(data.getLastPlacementYaw())) {
+            float yawDelta = Math.abs(currentYaw - data.getLastPlacementYaw());
+            if (yawDelta > 180) yawDelta = 360 - yawDelta;
+
+            PlayerData.PositionSnapshot curr = data.getLastPosition();
+            PlayerData.PositionSnapshot prev = data.getSecondLastPosition();
+            double horizSpeed = 0;
+            if (curr != null && prev != null) {
+                double hdx = curr.x() - prev.x();
+                double hdz = curr.z() - prev.z();
+                horizSpeed = Math.sqrt(hdx * hdx + hdz * hdz);
+            }
+
+            float rotLockThreshold = (float) getConfigDouble("rotation_lock_threshold", 2.0);
+            double minMoveSpeed = getConfigDouble("min_move_speed", 0.15);
+
+            if (yawDelta < rotLockThreshold && horizSpeed > minMoveSpeed) {
+                signalCount++;
+            }
+        }
+
+        data.setLastPlacementYaw(currentYaw);
+
+        // Signal 5: Placement interval variance
+        double minVarianceMs = getConfigDouble("min_placement_variance_ms", 30.0);
+        int minBpsForCheck = getConfigInt("min_bps_for_variance_check", 5);
+
+        if (data.getBlocksPerSecond() >= minBpsForCheck) {
+            double stdDev = computePlacementIntervalStdDev(data.getBlockPlaceTimestamps());
+            if (stdDev < minVarianceMs) {
+                signalCount++;
+            }
+        }
+        
+        return signalCount >= signalsRequired;
+    }
+
+    private double computePlacementIntervalStdDev(Deque<Long> timestamps) {
+        int size = timestamps.size();
+        if (size < 5) return Double.MAX_VALUE;
+
+        double sum = 0;
+        int intervalCount = 0;
+        Long prev = null;
+        for (Long ts : timestamps) {
+            if (prev != null) {
+                sum += (prev - ts);
+                intervalCount++;
+            }
+            prev = ts;
+        }
+        if (intervalCount == 0) return Double.MAX_VALUE;
+        double mean = sum / intervalCount;
+
+        double varianceSum = 0;
+        prev = null;
+        for (Long ts : timestamps) {
+            if (prev != null) {
+                double diff = (prev - ts) - mean;
+                varianceSum += diff * diff;
+            }
+            prev = ts;
+        }
+
+        return Math.sqrt(varianceSum / intervalCount);
+    }
+    
+    private boolean hasValidSupport(Block block) {
+        // Check adjacent blocks for support
+        Block[] adjacent = {
+            block.getRelative(org.bukkit.block.BlockFace.NORTH),
+            block.getRelative(org.bukkit.block.BlockFace.SOUTH),
+            block.getRelative(org.bukkit.block.BlockFace.EAST),
+            block.getRelative(org.bukkit.block.BlockFace.WEST),
+            block.getRelative(org.bukkit.block.BlockFace.DOWN)
+        };
+        
+        for (Block adj : adjacent) {
+            if (!adj.getType().isAir()) {
+                return true;
+            }
+        }
+        
+        return false;
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/movement/FlyCheck.java

@@ -0,0 +1,78 @@
+package com.xeroth.xeroanticheat.checks.movement;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+/**
+ * FlyCheck - Detects sustained upward or horizontal movement while the player
+ * has no creative/spectator mode, no elytra, no levitation, no jump boost.
+ * 
+ * Uses a fall buffer to allow for block stepping, slabs, trapdoors.
+ * Tracks ground desync between client and server.
+ */
+public class FlyCheck extends Check {
+
+    public FlyCheck(XeroAntiCheat plugin) {
+        super(plugin, "Fly");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Ignore elytra gliding
+        if (player.isGliding()) {
+            return;
+        }
+        
+        // Ignore if player has levitation effect
+        if (data.hasLevitation()) {
+            return;
+        }
+        
+        // Get fall buffer
+        int fallBuffer = getConfigInt("fall_buffer", 10);
+        
+        // Get position data
+        PlayerData.PositionSnapshot current = data.getLastPosition();
+        if (current == null) return;
+        
+        boolean clientOnGround = current.onGround();
+        boolean serverOnGround = player.isOnGround();
+        
+        // Check ground desync
+        int desyncThreshold = getConfigInt("ground_desync_threshold", 3);
+        if (clientOnGround != serverOnGround) {
+            if (data.getAirTicks() > fallBuffer + desyncThreshold) {
+                flag(data, player);
+            }
+        }
+        
+        // Check for sustained flight without ground
+        if (!serverOnGround && !clientOnGround) {
+            // Get velocity
+            org.bukkit.util.Vector velocity = player.getVelocity();
+            
+            // If moving up or staying at same height while not supposed to
+            if (velocity.getY() > 0.1 || Math.abs(velocity.getY()) < 0.01) {
+                if (data.getAirTicks() > fallBuffer) {
+                    // Additional check: see if player has jump boost
+                    if (!data.hasJumpBoost() || data.getJumpBoostLevel() <= 1) {
+                        flag(data, player);
+                    }
+                }
+            }
+        }
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/movement/GlideCheck.java

@@ -0,0 +1,73 @@
+package com.xeroth.xeroanticheat.checks.movement;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+/**
+ * GlideCheck - Detects players in non-elytra mode exhibiting glide-like fall curves
+ * (very slow Y decrease while moving horizontally fast).
+ * 
+ * Cross-references isGliding() with actual velocity.
+ */
+public class GlideCheck extends Check {
+
+    public GlideCheck(XeroAntiCheat plugin) {
+        super(plugin, "Glide");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Get thresholds
+        double minHorizontalSpeed = getConfigDouble("min_horizontal_speed", 0.5);
+        double maxYDecrease = getConfigDouble("max_y_decrease", 0.1);
+        
+        // Get velocity
+        org.bukkit.util.Vector velocity = player.getVelocity();
+        
+        // Calculate horizontal speed
+        double horizontalSpeed = Math.sqrt(velocity.getX() * velocity.getX() + velocity.getZ() * velocity.getZ());
+        
+        // Check if moving fast horizontally
+        if (horizontalSpeed < minHorizontalSpeed) {
+            data.resetGlideTicks();
+            return;
+        }
+        
+        // Check if player is gliding (with elytra)
+        if (player.isGliding()) {
+            data.resetGlideTicks();
+            return;
+        }
+        
+        // Check Y velocity - should be negative (falling)
+        double yVel = velocity.getY();
+        
+        // If falling very slowly (glide-like), flag
+        if (yVel < 0 && yVel > -maxYDecrease) {
+            // Only flag if sustained over multiple ticks
+            data.incrementGlideTicks();
+            
+            if (data.getGlideTicks() > 5) {
+                flag(data, player);
+            }
+        } else {
+            data.resetGlideTicks();
+        }
+        
+        // Track last gliding state
+        data.setLastWasGliding(player.isGliding());
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/movement/JesusCheck.java

@@ -0,0 +1,84 @@
+package com.xeroth.xeroanticheat.checks.movement;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.entity.Player;
+
+/**
+ * JesusCheck - Detects walking on water without Frost Walker enchantment or boat.
+ * 
+ * Checks block type beneath player feet on server side.
+ * Flags if water/lava but player maintains constant Y.
+ */
+public class JesusCheck extends Check {
+
+    public JesusCheck(XeroAntiCheat plugin) {
+        super(plugin, "Jesus");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Skip players swimming underwater
+        if (player.isSwimming()) return;
+        
+        // Get block below player
+        Location loc = player.getLocation();
+        Material blockBelow = loc.subtract(0, 1, 0).getBlock().getType();
+        
+        // Check if player is on water or lava
+        boolean onWater = blockBelow == Material.WATER;
+        boolean onLava = blockBelow == Material.LAVA;
+        
+        if (!onWater && !onLava) return;
+        
+        // Check if player is on a boat
+        if (player.getVehicle() != null) {
+            return;
+        }
+        
+        // Check for Frost Walker enchantment
+        org.bukkit.inventory.ItemStack boots = player.getInventory().getBoots();
+        boolean hasFrostWalker = false;
+        
+        if (boots != null && boots.hasItemMeta()) {
+            hasFrostWalker = boots.getItemMeta().hasEnchant(org.bukkit.enchantments.Enchantment.FROST_WALKER);
+        }
+        
+        // Check if player has Dolphins Grace (can swim faster)
+        if (data.hasDolphinsGrace()) {
+            return;
+        }
+        
+        // If player is walking on water without Frost Walker, flag
+        if (!hasFrostWalker) {
+            // Additional check: check if player is actually moving horizontally
+            PlayerData.PositionSnapshot current = data.getLastPosition();
+            PlayerData.PositionSnapshot last = data.getSecondLastPosition();
+            
+            if (current != null && last != null) {
+                double dx = current.x() - last.x();
+                double dz = current.z() - last.z();
+                double horizontalSpeed = Math.sqrt(dx * dx + dz * dz);
+                
+                // If moving at reasonable speed on water, flag
+                if (horizontalSpeed > 0.1) {
+                    flag(data, player);
+                }
+            }
+        }
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/movement/NoFallCheck.java

@@ -0,0 +1,84 @@
+package com.xeroth.xeroanticheat.checks.movement;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.entity.Player;
+
+/**
+ * NoFallCheck - Detects when a player takes no fall damage after falling more than 3 blocks.
+ * 
+ * Calculates expected fall damage when landing and stores it in PlayerData.
+ * Actual flagging happens in MiscListener via EntityDamageEvent.
+ */
+public class NoFallCheck extends Check {
+
+    public NoFallCheck(XeroAntiCheat plugin) {
+        super(plugin, "NoFall");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Ignore if player has slow falling (immune to fall damage)
+        if (data.hasSlowFalling()) {
+            data.setLastExpectedFallDamage(0.0);
+            return;
+        }
+        
+        // Get minimum fall distance
+        int minFallDistance = getConfigInt("min_fall_distance", 3);
+        
+        // Get server-computed fall distance
+        float fallDistance = player.getFallDistance();
+        
+        // Store fall distance
+        data.setLastFallDistance(fallDistance);
+        
+        // Check if player is on ground now with significant fall distance
+        if (player.isOnGround() && fallDistance > minFallDistance) {
+            // Calculate expected damage
+            double expectedDamage = (fallDistance - minFallDistance) / 2.0;
+            
+            // Check for damage-reducing blocks
+            Location loc = player.getLocation();
+            Material blockBelow = loc.subtract(0, 1, 0).getBlock().getType();
+            
+            // Blocks that reduce/cancel fall damage
+            if (blockBelow == Material.WATER ||
+                blockBelow == Material.HONEY_BLOCK ||
+                blockBelow == Material.HAY_BLOCK ||
+                blockBelow == Material.SLIME_BLOCK ||
+                blockBelow == Material.COBWEB) {
+                data.setLastExpectedFallDamage(0.0);
+                return;
+            }
+            
+            // Check for feather falling
+            org.bukkit.inventory.ItemStack boots = player.getInventory().getBoots();
+            if (boots != null && boots.hasItemMeta() && boots.getItemMeta().hasEnchant(org.bukkit.enchantments.Enchantment.FEATHER_FALLING)) {
+                int featherFallingLevel = boots.getItemMeta().getEnchantLevel(org.bukkit.enchantments.Enchantment.FEATHER_FALLING);
+                double multiplier = Math.max(0.0, 1.0 - (featherFallingLevel * 0.12));
+                expectedDamage *= multiplier;
+            }
+            
+            // Store expected damage for later comparison in EntityDamageEvent
+            data.setLastExpectedFallDamage(expectedDamage);
+        } else if (player.isOnGround()) {
+            // Reset when on ground with no fall
+            data.setLastExpectedFallDamage(0.0);
+        }
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/movement/PhaseCheck.java

@@ -0,0 +1,65 @@
+package com.xeroth.xeroanticheat.checks.movement;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.FluidCollisionMode;
+import org.bukkit.Location;
+import org.bukkit.entity.Player;
+import org.bukkit.util.RayTraceResult;
+import org.bukkit.util.Vector;
+
+/**
+ * PhaseCheck - Detects players clipping through solid blocks (NoClip/Phase).
+ *
+ * Uses a server-side ray-cast between the player's last two positions.
+ * If a solid block intersects the movement path, the player phased through it.
+ * Only runs when horizontal+vertical distance exceeds 0.5 blocks to avoid
+ * unnecessary ray-cast calls on micro-movements.
+ */
+public class PhaseCheck extends Check {
+
+    public PhaseCheck(XeroAntiCheat plugin) {
+        super(plugin, "Phase");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE
+                || player.getGameMode() == org.bukkit.GameMode.SPECTATOR) return;
+
+        if (isBypassed(player)) return;
+
+        PlayerData.PositionSnapshot curr = data.getLastPosition();
+        PlayerData.PositionSnapshot prev = data.getSecondLastPosition();
+        if (curr == null || prev == null) return;
+
+        double dx = curr.x() - prev.x();
+        double dy = curr.y() - prev.y();
+        double dz = curr.z() - prev.z();
+        double dist = Math.sqrt(dx * dx + dy * dy + dz * dz);
+
+        double minDist = getConfigDouble("min_distance", 0.5);
+        if (dist < minDist) return;
+
+        double maxDist = getConfigDouble("max_distance", 5.0);
+        if (dist > maxDist) return;
+
+        Location from = player.getEyeLocation().clone();
+        from.setX(prev.x());
+        from.setY(prev.y() + player.getEyeHeight());
+        from.setZ(prev.z());
+        Vector direction = new Vector(dx, dy, dz).normalize();
+
+        RayTraceResult result = player.getWorld().rayTraceBlocks(
+                from, direction, dist,
+                FluidCollisionMode.NEVER, true);
+
+        if (result != null && result.getHitBlock() != null
+                && result.getHitBlock().getType().isSolid()) {
+            flag(data, player, 3.0);
+        }
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/movement/SpeedCheck.java

@@ -0,0 +1,140 @@
+package com.xeroth.xeroanticheat.checks.movement;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.entity.Player;
+import org.bukkit.potion.PotionEffectType;
+
+/**
+ * SpeedCheck - Detects horizontal movement faster than the maximum possible speed
+ * for the player's current state (sprinting, walking, sneaking, swimming, on ice, etc.)
+ * 
+ * Uses rolling average over N ticks to avoid spike false positives.
+ * Accounts for server TPS fluctuation, ping compensation, and potion effects.
+ */
+public class SpeedCheck extends Check {
+
+    public SpeedCheck(XeroAntiCheat plugin) {
+        super(plugin, "Speed");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator mode
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Get current and last position
+        PlayerData.PositionSnapshot current = data.getLastPosition();
+        PlayerData.PositionSnapshot last = data.getSecondLastPosition();
+        
+        if (current == null || last == null) return;
+        
+        // Calculate time delta
+        long timeDelta = current.timestamp() - last.timestamp();
+        if (timeDelta <= 0) return;
+        
+        // Calculate horizontal distance
+        double dx = current.x() - last.x();
+        double dz = current.z() - last.z();
+        double horizontalDistance = Math.sqrt(dx * dx + dz * dz);
+        
+        // Calculate speed (blocks per tick)
+        double speed = horizontalDistance / (timeDelta / 50.0);
+        
+        // Get server TPS
+        double tps = org.bukkit.Bukkit.getTPS()[0];
+        double tpsMultiplier = 20.0 / Math.max(tps, 18.0);
+        
+        // Calculate max speed based on player state
+        double maxSpeed = calculateMaxSpeed(player, data);
+        
+        // Apply TPS compensation
+        maxSpeed *= tpsMultiplier;
+        
+        // Add latency compensation (scales with actual ping)
+        int ping = player.getPing();
+        double pingFactor = getConfigDouble("ping_factor", 1.0);
+        double latencyComp = Math.min(ping / 100.0 * 0.01 * pingFactor, 0.15);
+        maxSpeed += latencyComp;
+        
+        // Allow 10% tolerance
+        maxSpeed *= 1.1;
+        
+        // Check for knockback (recently damaged)
+        long knockbackGrace = 500; // ms
+        boolean recentlyDamaged = (System.currentTimeMillis() - data.getLastKnockbackTime()) < knockbackGrace;
+        
+        if (speed > maxSpeed * 1.5 && !recentlyDamaged) {
+            data.incrementSpeedViolationTicks();
+            int bufferTicks = getConfigInt("buffer_ticks", 5);
+            if (data.getSpeedViolationTicks() >= bufferTicks) {
+                flag(data, player, (speed - maxSpeed) * 2);
+                data.resetSpeedViolationTicks();
+            }
+        } else {
+            data.resetSpeedViolationTicks();
+        }
+    }
+
+    private double calculateMaxSpeed(Player player, PlayerData data) {
+        double baseSpeed = 0.56; // Base walking speed
+        
+        // Sprinting
+        if (player.isSprinting()) {
+            baseSpeed *= 1.3;
+        }
+        
+        // Sneaking
+        if (player.isSneaking()) {
+            baseSpeed *= 0.3;
+        }
+        
+        // Swimming
+        if (player.isSwimming()) {
+            baseSpeed *= 0.52;
+        }
+        
+        // Flying
+        if (player.isFlying()) {
+            baseSpeed = 1.0; // Fly speed
+        }
+        
+        // Potion effects
+        if (data.hasSpeedEffect()) {
+            baseSpeed *= (1.0 + (data.getSpeedLevel() * 0.2));
+        }
+        
+        if (data.hasSlownessEffect()) {
+            baseSpeed *= (1.0 - (data.getSlownessLevel() * 0.15));
+        }
+        
+        if (data.hasDolphinsGrace()) {
+            baseSpeed *= 1.33;
+        }
+        
+        // Ice
+        if (data.isOnIce()) {
+            baseSpeed *= 1.1;
+        }
+        
+        // Soul sand slows
+        Location loc = player.getLocation();
+        Material blockBelow = loc.subtract(0, 1, 0).getBlock().getType();
+        if (blockBelow == Material.SOUL_SAND || blockBelow == Material.SOUL_SOIL) {
+            baseSpeed *= 0.75;
+        }
+        
+        return baseSpeed;
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/movement/SpiderCheck.java

@@ -0,0 +1,89 @@
+package com.xeroth.xeroanticheat.checks.movement;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.entity.Player;
+
+/**
+ * SpiderCheck - Detects climbing non-climbable blocks (non-ladder, non-vine, non-scaffolding)
+ * with upward Y velocity.
+ * 
+ * Verifies block type at player's feet and body on server side.
+ */
+public class SpiderCheck extends Check {
+
+    public SpiderCheck(XeroAntiCheat plugin) {
+        super(plugin, "Spider");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+        
+        // Get velocity
+        org.bukkit.util.Vector velocity = player.getVelocity();
+        
+        // Only check if moving upward
+        if (velocity.getY() <= 0) {
+            data.resetSpiderTicks();
+            return;
+        }
+        
+        // Check if player is actually on ground (server-side)
+        if (player.isOnGround()) {
+            data.resetSpiderTicks();
+            return;
+        }
+        
+        // Get blocks around player
+        Location loc = player.getLocation();
+        
+        // Check block at feet
+        Material feetBlock = loc.subtract(0, 1, 0).getBlock().getType();
+        
+        // Check block at body level
+        Material bodyBlock = loc.getBlock().getType();
+        
+        // Check block above head
+        Material headBlock = loc.add(0, 1, 0).getBlock().getType();
+        
+        // Check if any of these blocks are climbable
+        boolean feetClimbable = isClimbable(feetBlock);
+        boolean bodyClimbable = isClimbable(bodyBlock);
+        boolean headClimbable = isClimbable(headBlock);
+        
+        // If not climbing any climbable block but moving up, flag
+        if (!feetClimbable && !bodyClimbable && !headClimbable) {
+            // Additional check - only flag if sustained upward movement
+            data.incrementSpiderTicks();
+            
+            if (data.getSpiderTicks() > 5 && velocity.getY() > 0.1) {
+                flag(data, player);
+            }
+        } else {
+            data.resetSpiderTicks();
+        }
+    }
+    
+    private boolean isClimbable(Material block) {
+        return block == Material.LADDER ||
+               block == Material.VINE ||
+               block == Material.SCAFFOLDING ||
+               block == Material.TWISTING_VINES ||
+               block == Material.WEEPING_VINES ||
+               block == Material.CAVE_VINES ||
+               block == Material.CAVE_VINES_PLANT;
+    }
+}

src/main/java/com/xeroth/xeroanticheat/checks/movement/TimerCheck.java

@@ -0,0 +1,84 @@
+package com.xeroth.xeroanticheat.checks.movement;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+/**
+ * TimerCheck - Detects players sending move packets faster than 20/second
+ * or packet suppression (blink) - player sends no move packets for >500ms then teleports.
+ * 
+ * Requires ProtocolLib for packet-level accuracy; falls back to event timing without it.
+ */
+public class TimerCheck extends Check {
+
+    public TimerCheck(XeroAntiCheat plugin) {
+        super(plugin, "Timer");
+    }
+
+    @Override
+    public void check(PlayerData data, Player player) {
+        if (!isEnabled()) return;
+        
+        // Ignore creative/spectator
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE || 
+            player.getGameMode() == org.bukkit.GameMode.SPECTATOR) {
+            return;
+        }
+        
+        // Ignore if player has bypass permission
+        if (isBypassed(player)) return;
+
+        // Get thresholds
+        int maxPacketsPerSecond = getConfigInt("max_packets_per_second", 22);
+        long blinkThresholdMs = getConfigInt("blink_threshold_ms", 500);
+
+        // If ProtocolLib is active, packet counting is handled by PacketListener
+        if (plugin.isProtocolLibLoaded()) {
+            if (data.getPacketsThisSecond() > maxPacketsPerSecond) {
+                flag(data, player, (data.getPacketsThisSecond() - maxPacketsPerSecond) * 0.5);
+            }
+            return;
+        }
+
+        // Reset packet count every second
+        long now = System.currentTimeMillis();
+        if (now - data.getLastPacketCountReset() > 1000) {
+            data.setPacketsThisSecond(0);
+            data.setLastPacketCountReset(now);
+        }
+        
+        // Increment packet count
+        data.incrementPacketsThisSecond();
+        
+        // Check for too many packets
+        if (data.getPacketsThisSecond() > maxPacketsPerSecond) {
+            flag(data, player, (data.getPacketsThisSecond() - maxPacketsPerSecond) * 0.5);
+        }
+        
+        // Check for blink (packet suppression)
+        long lastMoveTime = data.getLastMovePacketTime();
+        if (lastMoveTime > 0) {
+            long gap = now - lastMoveTime;
+            if (gap > blinkThresholdMs) {
+                // Check if player teleported during the gap
+                PlayerData.PositionSnapshot current = data.getLastPosition();
+                PlayerData.PositionSnapshot last = data.getSecondLastPosition();
+                if (current != null && last != null) {
+                    double dx = current.x() - last.x();
+                    double dy = current.y() - last.y();
+                    double dz = current.z() - last.z();
+                    double distance = Math.sqrt(dx*dx + dy*dy + dz*dz);
+                    
+                    // If teleported more than 10 blocks, likely blink
+                    if (distance > 10) {
+                        flag(data, player, 2.0);
+                    }
+                }
+            }
+        }
+        
+        data.setLastMovePacketTime(now);
+    }
+}

src/main/java/com/xeroth/xeroanticheat/command/XACCommand.java

@@ -0,0 +1,254 @@
+package com.xeroth.xeroanticheat.command;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.format.NamedTextColor;
+import org.bukkit.Bukkit;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+import org.bukkit.command.TabCompleter;
+import org.bukkit.entity.Player;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.stream.Stream;
+
+public class XACCommand implements CommandExecutor, TabCompleter {
+
+    private final XeroAntiCheat plugin;
+
+    public XACCommand(XeroAntiCheat plugin) {
+        this.plugin = plugin;
+    }
+
+    @Override
+    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
+        if (args.length == 0) {
+            sendHelp(sender);
+            return true;
+        }
+
+        switch (args[0].toLowerCase()) {
+            case "reload" -> {
+                if (!has(sender, "xac.command.reload")) return true;
+                reload(sender);
+            }
+            case "status" -> {
+                if (!has(sender, "xac.command.status")) return true;
+                if (args.length < 2) {
+                    sender.sendMessage(usage("/xac status <player>"));
+                    return true;
+                }
+                showStatus(sender, args[1]);
+            }
+            case "punish" -> {
+                if (!has(sender, "xac.command.punish")) return true;
+                if (args.length < 3) {
+                    sender.sendMessage(usage("/xac punish <player> <check>"));
+                    return true;
+                }
+                punish(sender, args[1], args[2]);
+            }
+            case "clearviolations" -> {
+                if (!has(sender, "xac.command.clearviolations")) return true;
+                if (args.length < 2) {
+                    sender.sendMessage(usage("/xac clearviolations <player>"));
+                    return true;
+                }
+                clearViolations(sender, args[1]);
+            }
+            case "verbose" -> {
+                if (!has(sender, "xac.command.verbose")) return true;
+                if (args.length < 2) {
+                    sender.sendMessage(usage("/xac verbose <player>"));
+                    return true;
+                }
+                toggleVerbose(sender, args[1]);
+            }
+            case "alerts" -> {
+                if (!has(sender, "xac.command.alerts")) return true;
+                if (args.length < 2) {
+                    boolean current = sender instanceof Player p && plugin.isAlertsEnabled(p.getUniqueId());
+                    sender.sendMessage(Component.text("Alerts: " + (current ? "ON" : "OFF"), NamedTextColor.YELLOW));
+                    return true;
+                }
+                toggleAlerts(sender, args[1]);
+            }
+            case "version" -> showVersion(sender);
+            default -> sendHelp(sender);
+        }
+        return true;
+    }
+
+    private boolean has(CommandSender sender, String permission) {
+        if (sender.hasPermission(permission) || sender.hasPermission("xac.admin")) return true;
+        sender.sendMessage(Component.text(
+            "You don't have permission to use this command. (requires " + permission + ")",
+            NamedTextColor.RED));
+        return false;
+    }
+
+    private Component usage(String text) {
+        return Component.text("Usage: " + text, NamedTextColor.RED);
+    }
+
+    private void sendHelp(CommandSender sender) {
+        sender.sendMessage(Component.text("— XeroAntiCheat —", NamedTextColor.GOLD));
+
+        record Cmd(String syntax, String desc, String perm) {}
+        List.of(
+            new Cmd("/xac reload", "reload config", "xac.command.reload"),
+            new Cmd("/xac status <player>", "view violation levels", "xac.command.status"),
+            new Cmd("/xac punish <player> <check>", "manual punishment", "xac.command.punish"),
+            new Cmd("/xac clearviolations <player>", "clear all VL for player", "xac.command.clearviolations"),
+            new Cmd("/xac verbose <player>", "toggle per-flag debug", "xac.command.verbose"),
+            new Cmd("/xac alerts [on|off]", "toggle alert receiving", "xac.command.alerts"),
+            new Cmd("/xac version", "show version", "xac.command.version")
+        ).forEach(cmd -> {
+            if (sender.hasPermission(cmd.perm()) || sender.hasPermission("xac.admin")) {
+                sender.sendMessage(
+                    Component.text(cmd.syntax(), NamedTextColor.AQUA)
+                        .append(Component.text(" — " + cmd.desc(), NamedTextColor.GRAY))
+                );
+            }
+        });
+    }
+
+    private void reload(CommandSender sender) {
+        plugin.reload();
+        plugin.getCheckManager().reloadChecks();
+        sender.sendMessage(Component.text("Configuration reloaded!", NamedTextColor.GREEN));
+    }
+
+    private void showStatus(CommandSender sender, String playerName) {
+        Player target = Bukkit.getPlayer(playerName);
+        
+        if (target == null) {
+            sender.sendMessage(Component.text("Player not found or not online.", NamedTextColor.RED));
+            return;
+        }
+        
+        PlayerData data = plugin.getViolationManager().getPlayerData(target);
+        
+        if (data == null) {
+            sender.sendMessage(Component.text("No data for player", NamedTextColor.RED));
+            return;
+        }
+        
+        sender.sendMessage(Component.text("=== " + target.getName() + " Violation Status ===", NamedTextColor.GOLD));
+        
+        if (data.getViolationLevels().isEmpty()) {
+            sender.sendMessage(Component.text("No violations", NamedTextColor.GREEN));
+        } else {
+            for (var entry : data.getViolationLevels().entrySet()) {
+                sender.sendMessage(Component.text(entry.getKey() + ": " + String.format("%.1f", entry.getValue()), 
+                    NamedTextColor.WHITE));
+            }
+        }
+        
+        sender.sendMessage(Component.text("Ping: " + target.getPing() + "ms", NamedTextColor.YELLOW));
+        
+        if (!data.getLastFlaggedCheck().isEmpty()) {
+            sender.sendMessage(Component.text("Last flagged: " + data.getLastFlaggedCheck(), NamedTextColor.YELLOW));
+        }
+    }
+
+    private void punish(CommandSender sender, String playerName, String checkName) {
+        Player target = Bukkit.getPlayer(playerName);
+        
+        if (target == null) {
+            sender.sendMessage(Component.text("Player not found or not online.", NamedTextColor.RED));
+            return;
+        }
+        
+        plugin.getPunishmentManager().manualPunish(target, checkName);
+        sender.sendMessage(Component.text("Punishment applied to " + target.getName() + " for " + checkName, 
+            NamedTextColor.GREEN));
+    }
+
+    private void clearViolations(CommandSender sender, String playerName) {
+        Player target = Bukkit.getPlayer(playerName);
+        
+        if (target == null) {
+            sender.sendMessage(Component.text("Player not found or not online.", NamedTextColor.RED));
+            return;
+        }
+        
+        plugin.getViolationManager().getPlayerData(target).getViolationLevels().clear();
+        sender.sendMessage(Component.text(
+            "Cleared all violations for " + target.getName() + ".", NamedTextColor.GREEN));
+        plugin.getLogger().info(
+            sender.getName() + " cleared violations for " + target.getName());
+    }
+
+    private void toggleVerbose(CommandSender sender, String playerName) {
+        Player target = Bukkit.getPlayer(playerName);
+        
+        if (target == null) {
+            sender.sendMessage(Component.text("Player not found or not online.", NamedTextColor.RED));
+            return;
+        }
+        
+        plugin.toggleVerboseTarget(target.getUniqueId());
+        boolean now = plugin.isVerboseTarget(target.getUniqueId());
+        sender.sendMessage(Component.text(
+            "Verbose for " + target.getName() + ": " + (now ? "ON" : "OFF"),
+            now ? NamedTextColor.GREEN : NamedTextColor.YELLOW));
+    }
+
+    private void toggleAlerts(CommandSender sender, String state) {
+        if (!(sender instanceof Player player)) {
+            sender.sendMessage(Component.text("Only players can toggle alerts", NamedTextColor.RED));
+            return;
+        }
+        
+        boolean newState = state.equalsIgnoreCase("on");
+        plugin.setAlertsEnabled(player.getUniqueId(), newState);
+        
+        sender.sendMessage(Component.text("Alerts " + (newState ? "enabled" : "disabled"), 
+            NamedTextColor.GREEN));
+    }
+
+    private void showVersion(CommandSender sender) {
+        sender.sendMessage(Component.text("XeroAntiCheat v" + plugin.getDescription().getVersion(), 
+            NamedTextColor.GOLD));
+        sender.sendMessage(Component.text("Built for Paper 1.21.x", NamedTextColor.WHITE));
+    }
+
+    @Override
+    public List<String> onTabComplete(CommandSender sender, Command command, String alias, String[] args) {
+        if (args.length == 1) {
+            return Stream.of("reload","status","punish","clearviolations","verbose","alerts","version")
+                .filter(sub -> sender.hasPermission("xac.command." + sub)
+                            || sender.hasPermission("xac.admin"))
+                .filter(sub -> sub.startsWith(args[0].toLowerCase()))
+                .toList();
+        }
+        if (args.length == 2) {
+            String sub = args[0].toLowerCase();
+            if (List.of("status","punish","clearviolations","verbose").contains(sub)) {
+                return Bukkit.getOnlinePlayers().stream()
+                    .map(Player::getName)
+                    .filter(n -> n.toLowerCase().startsWith(args[1].toLowerCase()))
+                    .toList();
+            }
+            if (sub.equals("alerts")) return List.of("on","off");
+        }
+        if (args.length == 3 && args[0].equalsIgnoreCase("punish")) {
+            return plugin.getCheckManager().getRegisteredChecks().stream()
+                .map(c -> c.getName())
+                .filter(n -> n.toLowerCase().startsWith(args[2].toLowerCase()))
+                .toList();
+        }
+        return List.of();
+    }
+    
+    public boolean hasAlertsEnabled(UUID uuid) {
+        return plugin.isAlertsEnabled(uuid);
+    }
+}

src/main/java/com/xeroth/xeroanticheat/data/PlayerData.java

@@ -0,0 +1,640 @@
+package com.xeroth.xeroanticheat.data;
+
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.entity.Player;
+import org.bukkit.potion.PotionEffectType;
+
+import java.util.ArrayDeque;
+import java.util.Collections;
+import java.util.Deque;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Stores per-player state for anti-cheat tracking.
+ * Thread-safe implementation using ConcurrentHashMap and ArrayDeque.
+ */
+public class PlayerData {
+
+    private final UUID uuid;
+    private final String name;
+    
+    // Position history (fixed-size ring buffer)
+    private final Deque<PositionSnapshot> positionHistory = new ArrayDeque<>(20);
+    
+    // Velocity history
+    private final Deque<VelocitySnapshot> velocityHistory = new ArrayDeque<>(10);
+    
+    // Rotation history
+    private final Deque<RotationSnapshot> rotationHistory = new ArrayDeque<>(10);
+    
+    // Violation levels per check
+    private final Map<String, Double> violationLevels = new ConcurrentHashMap<>();
+    
+    // Combat tracking
+    private final Deque<Long> clickTimestamps = new ArrayDeque<>(20);
+    private final Deque<Long> attackTimestamps  = new ArrayDeque<>(10);
+    private final Deque<UUID> attackedEntities = new ArrayDeque<>(10);
+    
+    // Movement state
+    private boolean lastOnGround = true;
+    private boolean isOnIce = false;
+    private boolean wasAirborne = false;
+    private int airTicks = 0;
+    private int groundTicks = 0;
+    private float lastFallDistance = 0f;
+    private boolean lastWasGliding = false;
+    
+    // Ping
+    private int ping = 0;
+    
+    // Potion effects (cached)
+    private boolean hasSpeedEffect = false;
+    private boolean hasSlownessEffect = false;
+    private boolean hasDolphinsGrace = false;
+    private boolean hasLevitation = false;
+    private boolean hasJumpBoost = false;
+    private boolean hasSlowFalling = false;
+    private int speedLevel = 0;
+    private int slownessLevel = 0;
+    private int jumpBoostLevel = 0;
+    
+    // Player state
+    private boolean inventoryOpen = false;
+    private long lastEatTime = 0;
+    private boolean wasSprinting = false;
+    
+    // Block placement tracking
+    private final Deque<Long> blockPlaceTimestamps = new ArrayDeque<>(20);
+    
+    // Scaffold tracking
+    private int scaffoldSignals = 0;
+    
+    // Timer check
+    private long lastMovePacketTime = 0;
+    private int packetsThisSecond = 0;
+    private long lastPacketCountReset = 0;
+    
+    // Last flagged check
+    private String lastFlaggedCheck = "";
+    private long lastFlagTime = 0;
+    
+    // Combat angles
+    private float lastYaw = 0;
+    private float lastPitch = 0;
+    private float lastAttackYaw = 0;
+    
+    // Knockback tracking
+    private long lastKnockbackTime = 0;
+    
+    // NoFall tracking
+    private double lastExpectedFallDamage = 0.0;
+    
+    // FastEat tracking
+    private long lastStartedEatingTime = 0;
+    
+    // Scaffold tracking
+    private float lastPlacementYaw = Float.NaN;
+    
+    // VelocityCheck tracking
+    private org.bukkit.util.Vector lastServerVelocity = null;
+    private int velocityCheckTicks = 0;
+    
+    // SpiderCheck tracking
+    private int spiderTicks = 0;
+    
+    // GlideCheck tracking
+    private int glideTicks = 0;
+    
+    // SpeedCheck tracking
+    private int speedViolationTicks = 0;
+    
+    public PlayerData(Player player) {
+        this.uuid = player.getUniqueId();
+        this.name = player.getName();
+    }
+
+    // Position methods
+    public void addPosition(double x, double y, double z, boolean onGround) {
+        positionHistory.addFirst(new PositionSnapshot(x, y, z, onGround, System.currentTimeMillis()));
+        if (positionHistory.size() > 20) {
+            positionHistory.removeLast();
+        }
+    }
+
+    public PositionSnapshot getLastPosition() {
+        return positionHistory.peekFirst();
+    }
+
+    public PositionSnapshot getSecondLastPosition() {
+        if (positionHistory.size() < 2) return null;
+        var it = positionHistory.iterator();
+        it.next();
+        return it.next();
+    }
+
+    // Velocity methods
+    public void addVelocity(double x, double y, double z) {
+        velocityHistory.addFirst(new VelocitySnapshot(x, y, z, System.currentTimeMillis()));
+        if (velocityHistory.size() > 10) {
+            velocityHistory.removeLast();
+        }
+    }
+
+    // Rotation methods
+    public void addRotation(float yaw, float pitch) {
+        rotationHistory.addFirst(new RotationSnapshot(yaw, pitch, System.currentTimeMillis()));
+        if (rotationHistory.size() > 10) {
+            rotationHistory.removeLast();
+        }
+    }
+
+    public RotationSnapshot getLastRotation() {
+        return rotationHistory.peekFirst();
+    }
+
+    // Click tracking
+    public void addClick() {
+        long now = System.currentTimeMillis();
+        clickTimestamps.addFirst(now);
+        
+        // Remove old clicks (>1 second)
+        while (!clickTimestamps.isEmpty() && now - clickTimestamps.peekLast() > 1000) {
+            clickTimestamps.removeLast();
+        }
+    }
+
+    public int getCPS() {
+        long now = System.currentTimeMillis();
+        int count = 0;
+        for (Long timestamp : clickTimestamps) {
+            if (now - timestamp <= 1000) {
+                count++;
+            }
+        }
+        return count;
+    }
+
+    // Attack tracking
+    public void addAttack(UUID entityId) {
+        long now = System.currentTimeMillis();
+        attackTimestamps.addFirst(now);
+        attackedEntities.addFirst(entityId);
+        
+        while (attackTimestamps.size() > 10) {
+            attackTimestamps.removeLast();
+        }
+        while (attackedEntities.size() > 10) {
+            attackedEntities.removeLast();
+        }
+    }
+
+    public int getAttacksPerSecond() {
+        long now = System.currentTimeMillis();
+        int count = 0;
+        for (Long timestamp : attackTimestamps) {
+            if (now - timestamp <= 1000) {
+                count++;
+            }
+        }
+        return count;
+    }
+
+    // Violation methods
+    public void setViolationLevel(String check, double vl) {
+        violationLevels.put(check, vl);
+    }
+
+    public double getViolationLevel(String check) {
+        return violationLevels.getOrDefault(check, 0.0);
+    }
+
+    public void incrementViolation(String check, double amount) {
+        violationLevels.merge(check, amount, (a, b) -> a + b);
+    }
+
+    public void decayViolation(String check, double amount) {
+        violationLevels.computeIfPresent(check, (k, v) -> Math.max(0, v - amount));
+    }
+
+    // Block place tracking
+    public void addBlockPlace() {
+        long now = System.currentTimeMillis();
+        blockPlaceTimestamps.addFirst(now);
+        
+        while (!blockPlaceTimestamps.isEmpty() && now - blockPlaceTimestamps.peekLast() > 1000) {
+            blockPlaceTimestamps.removeLast();
+        }
+    }
+
+    public int getBlocksPerSecond() {
+        long now = System.currentTimeMillis();
+        int count = 0;
+        for (Long timestamp : blockPlaceTimestamps) {
+            if (now - timestamp <= 1000) {
+                count++;
+            }
+        }
+        return count;
+    }
+
+    // Getters and setters
+    public UUID getUuid() {
+        return uuid;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public boolean isLastOnGround() {
+        return lastOnGround;
+    }
+
+    public void setLastOnGround(boolean lastOnGround) {
+        this.lastOnGround = lastOnGround;
+    }
+
+    public boolean isOnIce() {
+        return isOnIce;
+    }
+
+    public void setOnIce(boolean onIce) {
+        isOnIce = onIce;
+    }
+
+    public boolean wasAirborne() {
+        return wasAirborne;
+    }
+
+    public void setWasAirborne(boolean wasAirborne) {
+        this.wasAirborne = wasAirborne;
+    }
+
+    public int getAirTicks() {
+        return airTicks;
+    }
+
+    public void setAirTicks(int airTicks) {
+        this.airTicks = airTicks;
+    }
+
+    public void incrementAirTicks() {
+        this.airTicks++;
+    }
+
+    public void resetAirTicks() {
+        this.airTicks = 0;
+    }
+
+    public int getGroundTicks() {
+        return groundTicks;
+    }
+
+    public void setGroundTicks(int groundTicks) {
+        this.groundTicks = groundTicks;
+    }
+
+    public float getLastFallDistance() {
+        return lastFallDistance;
+    }
+
+    public void setLastFallDistance(float lastFallDistance) {
+        this.lastFallDistance = lastFallDistance;
+    }
+
+    public boolean wasLastGliding() {
+        return lastWasGliding;
+    }
+
+    public void setLastWasGliding(boolean lastWasGliding) {
+        this.lastWasGliding = lastWasGliding;
+    }
+
+    public int getPing() {
+        return ping;
+    }
+
+    public void setPing(int ping) {
+        this.ping = ping;
+    }
+
+    public boolean hasSpeedEffect() {
+        return hasSpeedEffect;
+    }
+
+    public void setHasSpeedEffect(boolean hasSpeedEffect) {
+        this.hasSpeedEffect = hasSpeedEffect;
+    }
+
+    public boolean hasSlownessEffect() {
+        return hasSlownessEffect;
+    }
+
+    public void setHasSlownessEffect(boolean hasSlownessEffect) {
+        this.hasSlownessEffect = hasSlownessEffect;
+    }
+
+    public boolean hasDolphinsGrace() {
+        return hasDolphinsGrace;
+    }
+
+    public void setHasDolphinsGrace(boolean hasDolphinsGrace) {
+        this.hasDolphinsGrace = hasDolphinsGrace;
+    }
+
+    public boolean hasLevitation() {
+        return hasLevitation;
+    }
+
+    public void setHasLevitation(boolean hasLevitation) {
+        this.hasLevitation = hasLevitation;
+    }
+
+    public boolean hasJumpBoost() {
+        return hasJumpBoost;
+    }
+
+    public void setHasJumpBoost(boolean hasJumpBoost) {
+        this.hasJumpBoost = hasJumpBoost;
+    }
+
+    public boolean hasSlowFalling() {
+        return hasSlowFalling;
+    }
+
+    public void setHasSlowFalling(boolean hasSlowFalling) {
+        this.hasSlowFalling = hasSlowFalling;
+    }
+
+    public int getSpeedLevel() {
+        return speedLevel;
+    }
+
+    public void setSpeedLevel(int speedLevel) {
+        this.speedLevel = speedLevel;
+    }
+
+    public int getSlownessLevel() {
+        return slownessLevel;
+    }
+
+    public void setSlownessLevel(int slownessLevel) {
+        this.slownessLevel = slownessLevel;
+    }
+
+    public int getJumpBoostLevel() {
+        return jumpBoostLevel;
+    }
+
+    public void setJumpBoostLevel(int jumpBoostLevel) {
+        this.jumpBoostLevel = jumpBoostLevel;
+    }
+
+    public boolean isInventoryOpen() {
+        return inventoryOpen;
+    }
+
+    public void setInventoryOpen(boolean inventoryOpen) {
+        this.inventoryOpen = inventoryOpen;
+    }
+
+    public long getLastEatTime() {
+        return lastEatTime;
+    }
+
+    public void setLastEatTime(long lastEatTime) {
+        this.lastEatTime = lastEatTime;
+    }
+
+    public boolean wasSprinting() {
+        return wasSprinting;
+    }
+
+    public void setWasSprinting(boolean wasSprinting) {
+        this.wasSprinting = wasSprinting;
+    }
+
+    public int getScaffoldSignals() {
+        return scaffoldSignals;
+    }
+
+    public void setScaffoldSignals(int scaffoldSignals) {
+        this.scaffoldSignals = scaffoldSignals;
+    }
+
+    public void incrementScaffoldSignals() {
+        this.scaffoldSignals++;
+    }
+
+    public void resetScaffoldSignals() {
+        this.scaffoldSignals = 0;
+    }
+
+    public long getLastMovePacketTime() {
+        return lastMovePacketTime;
+    }
+
+    public void setLastMovePacketTime(long lastMovePacketTime) {
+        this.lastMovePacketTime = lastMovePacketTime;
+    }
+
+    public int getPacketsThisSecond() {
+        return packetsThisSecond;
+    }
+
+    public void setPacketsThisSecond(int packetsThisSecond) {
+        this.packetsThisSecond = packetsThisSecond;
+    }
+
+    public void incrementPacketsThisSecond() {
+        this.packetsThisSecond++;
+    }
+
+    public long getLastPacketCountReset() {
+        return lastPacketCountReset;
+    }
+
+    public void setLastPacketCountReset(long lastPacketCountReset) {
+        this.lastPacketCountReset = lastPacketCountReset;
+    }
+
+    public String getLastFlaggedCheck() {
+        return lastFlaggedCheck;
+    }
+
+    public void setLastFlaggedCheck(String lastFlaggedCheck) {
+        this.lastFlaggedCheck = lastFlaggedCheck;
+    }
+
+    public long getLastFlagTime() {
+        return lastFlagTime;
+    }
+
+    public void setLastFlagTime(long lastFlagTime) {
+        this.lastFlagTime = lastFlagTime;
+    }
+
+    public float getLastYaw() {
+        return lastYaw;
+    }
+
+    public void setLastYaw(float lastYaw) {
+        this.lastYaw = lastYaw;
+    }
+
+    public float getLastPitch() {
+        return lastPitch;
+    }
+
+    public void setLastPitch(float lastPitch) {
+        this.lastPitch = lastPitch;
+    }
+
+    public float getLastAttackYaw() {
+        return lastAttackYaw;
+    }
+
+    public void setLastAttackYaw(float lastAttackYaw) {
+        this.lastAttackYaw = lastAttackYaw;
+    }
+
+    public Deque<Long> getClickTimestamps() {
+        return clickTimestamps;
+    }
+
+    public Deque<UUID> getAttackedEntities() {
+        return attackedEntities;
+    }
+
+    public Deque<Long> getAttackTimestamps() {
+        return attackTimestamps;
+    }
+
+    public Map<String, Double> getViolationLevels() {
+        return violationLevels;
+    }
+
+    public long getLastKnockbackTime() {
+        return lastKnockbackTime;
+    }
+
+    public void setLastKnockbackTime(long lastKnockbackTime) {
+        this.lastKnockbackTime = lastKnockbackTime;
+    }
+
+    public double getLastExpectedFallDamage() {
+        return lastExpectedFallDamage;
+    }
+
+    public void setLastExpectedFallDamage(double lastExpectedFallDamage) {
+        this.lastExpectedFallDamage = lastExpectedFallDamage;
+    }
+
+    public long getLastStartedEatingTime() {
+        return lastStartedEatingTime;
+    }
+
+    public void setLastStartedEatingTime(long lastStartedEatingTime) {
+        this.lastStartedEatingTime = lastStartedEatingTime;
+    }
+
+    public float getLastPlacementYaw() {
+        return lastPlacementYaw;
+    }
+
+    public void setLastPlacementYaw(float lastPlacementYaw) {
+        this.lastPlacementYaw = lastPlacementYaw;
+    }
+
+    public org.bukkit.util.Vector getLastServerVelocity() {
+        return lastServerVelocity;
+    }
+
+    public void setLastServerVelocity(org.bukkit.util.Vector v) {
+        this.lastServerVelocity = v;
+        this.velocityCheckTicks = 4;
+    }
+
+    public int getVelocityCheckTicks() {
+        return velocityCheckTicks;
+    }
+
+    public void decrementVelocityCheckTicks() {
+        if (velocityCheckTicks > 0) velocityCheckTicks--;
+    }
+
+    public void clearServerVelocity() {
+        lastServerVelocity = null;
+        velocityCheckTicks = 0;
+    }
+    
+    // Spider tick methods
+    public int getSpiderTicks() {
+        return spiderTicks;
+    }
+    
+    public void setSpiderTicks(int spiderTicks) {
+        this.spiderTicks = spiderTicks;
+    }
+    
+    public void incrementSpiderTicks() {
+        this.spiderTicks++;
+    }
+    
+    public void resetSpiderTicks() {
+        this.spiderTicks = 0;
+    }
+    
+    // Glide tick methods
+    public int getGlideTicks() {
+        return glideTicks;
+    }
+    
+    public void setGlideTicks(int glideTicks) {
+        this.glideTicks = glideTicks;
+    }
+    
+    public void incrementGlideTicks() {
+        this.glideTicks++;
+    }
+    
+    public void resetGlideTicks() {
+        this.glideTicks = 0;
+    }
+    
+    // Speed violation tick methods
+    public int getSpeedViolationTicks() {
+        return speedViolationTicks;
+    }
+    
+    public void incrementSpeedViolationTicks() {
+        this.speedViolationTicks++;
+    }
+    
+    public void resetSpeedViolationTicks() {
+        this.speedViolationTicks = 0;
+    }
+    
+    public void clearPositionHistory() {
+        positionHistory.clear();
+        rotationHistory.clear();
+        velocityHistory.clear();
+        spiderTicks = 0;
+        glideTicks = 0;
+        speedViolationTicks = 0;
+    }
+
+    public Deque<Long> getBlockPlaceTimestamps() {
+        return blockPlaceTimestamps;
+    }
+
+    // Snapshots
+    public record PositionSnapshot(double x, double y, double z, boolean onGround, long timestamp) {}
+    
+    public record VelocitySnapshot(double x, double y, double z, long timestamp) {}
+    
+    public record RotationSnapshot(float yaw, float pitch, long timestamp) {}
+}

src/main/java/com/xeroth/xeroanticheat/listener/CombatListener.java

@@ -0,0 +1,118 @@
+package com.xeroth.xeroanticheat.listener;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.checks.combat.AutoClickerCheck;
+import com.xeroth.xeroanticheat.checks.combat.CriticalCheck;
+import com.xeroth.xeroanticheat.checks.combat.KillAuraCheck;
+import com.xeroth.xeroanticheat.checks.combat.ReachCheck;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.EntityDamageByEntityEvent;
+import org.bukkit.event.player.PlayerInteractEvent;
+
+/**
+ * CombatListener - Handles combat-related events for anti-cheat checks.
+ */
+public class CombatListener implements Listener {
+
+    private final XeroAntiCheat plugin;
+
+    public CombatListener(XeroAntiCheat plugin) {
+        this.plugin = plugin;
+    }
+
+    @EventHandler(priority = EventPriority.LOW)
+    public void onEntityDamageByEntity(EntityDamageByEntityEvent event) {
+        Entity damager = event.getDamager();
+        
+        // Only check if damager is a player
+        if (!(damager instanceof Player player)) return;
+        
+        // Early-return for players with global bypass only.
+        // Category and per-check bypass is enforced inside Check.flag() and isBypassed() guards.
+        if (player.hasPermission("xac.bypass")) return;
+        
+        Entity target = event.getEntity();
+        
+        // Get player data
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        
+        // Record attack
+        data.addAttack(target.getUniqueId());
+        
+        // Get checks
+        KillAuraCheck killAuraCheck = (KillAuraCheck) plugin.getCheckManager().getCheck("KillAura");
+        ReachCheck reachCheck = (ReachCheck) plugin.getCheckManager().getCheck("Reach");
+        CriticalCheck criticalCheck = (CriticalCheck) plugin.getCheckManager().getCheck("Critical");
+        
+        // Check for reach
+        if (reachCheck != null && reachCheck.checkReach(player, target)) {
+            if (!reachCheck.isBypassed(player)) {
+                plugin.getViolationManager().addViolation(player, "Reach", 1.0);
+                plugin.getPunishmentManager().evaluate(player, "Reach");
+            }
+        }
+        
+        // Check for kill aura (angle)
+        if (killAuraCheck != null && killAuraCheck.checkAngle(player, target)) {
+            if (!killAuraCheck.isBypassed(player)) {
+                plugin.getViolationManager().addViolation(player, "KillAura", 1.0);
+                plugin.getPunishmentManager().evaluate(player, "KillAura");
+            }
+        }
+        
+        // Check for multi-target
+        if (killAuraCheck != null && killAuraCheck.checkMultiTarget(data, player, target)) {
+            if (!killAuraCheck.isBypassed(player)) {
+                plugin.getViolationManager().addViolation(player, "KillAura", 2.0);
+                plugin.getPunishmentManager().evaluate(player, "KillAura");
+            }
+        }
+        
+        // Check for critical hits
+        if (criticalCheck != null) {
+            double yVelocity = player.getVelocity().getY();
+            boolean isCritical = yVelocity < -0.08
+                    && !player.isOnGround()
+                    && !player.isInsideVehicle()
+                    && player.getFallDistance() > 0.0;
+            
+            if (criticalCheck.checkCritical(player, data, isCritical)) {
+                if (!criticalCheck.isBypassed(player)) {
+                    plugin.getViolationManager().addViolation(player, "Critical", 1.0);
+                    plugin.getPunishmentManager().evaluate(player, "Critical");
+                }
+            }
+        }
+        
+        // Update wasAirborne state after attack
+        data.setWasAirborne(!player.isOnGround());
+    }
+
+    @EventHandler(priority = EventPriority.LOW)
+    public void onPlayerInteract(PlayerInteractEvent event) {
+        Player player = event.getPlayer();
+        
+        // Early-return for players with global bypass only.
+        // Category and per-check bypass is enforced inside Check.flag() and isBypassed() guards.
+        if (player.hasPermission("xac.bypass")) return;
+        
+        // Get player data
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        
+        // Record click for autoclicker check
+        // Only count left clicks (attack)
+        if (event.getAction().name().contains("LEFT_CLICK")) {
+            if (!plugin.isProtocolLibLoaded()) {
+                data.addClick();
+            }
+            
+            // Run autoclicker check
+            plugin.getCheckManager().runCheck("AutoClicker", data, player);
+        }
+    }
+}

src/main/java/com/xeroth/xeroanticheat/listener/MiscListener.java

@@ -0,0 +1,161 @@
+package com.xeroth.xeroanticheat.listener;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.checks.misc.FastEatCheck;
+import com.xeroth.xeroanticheat.checks.misc.FastPlaceCheck;
+import com.xeroth.xeroanticheat.checks.misc.ScaffoldCheck;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.Material;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.block.BlockPlaceEvent;
+import org.bukkit.event.entity.EntityDamageByEntityEvent;
+import org.bukkit.event.entity.EntityDamageEvent;
+import org.bukkit.event.inventory.InventoryCloseEvent;
+import org.bukkit.event.inventory.InventoryOpenEvent;
+import org.bukkit.event.player.PlayerInteractEvent;
+import org.bukkit.event.player.PlayerItemConsumeEvent;
+import org.bukkit.event.player.PlayerRespawnEvent;
+
+/**
+ * MiscListener - Handles miscellaneous events for anti-cheat checks.
+ */
+public class MiscListener implements Listener {
+
+    private final XeroAntiCheat plugin;
+
+    public MiscListener(XeroAntiCheat plugin) {
+        this.plugin = plugin;
+    }
+
+    @EventHandler(priority = EventPriority.LOW)
+    public void onBlockPlace(BlockPlaceEvent event) {
+        Player player = event.getPlayer();
+        
+        // Early-return for players with global bypass only.
+        // Category and per-check bypass is enforced inside Check.flag() and isBypassed() guards.
+        if (player.hasPermission("xac.bypass")) return;
+        
+        // Ignore creative mode
+        if (player.getGameMode() == org.bukkit.GameMode.CREATIVE) return;
+        
+        // Get player data
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        
+        // Record block placement
+        data.addBlockPlace();
+        
+        // Run fastplace check
+        plugin.getCheckManager().runCheck("FastPlace", data, player);
+        
+        // Run scaffold check
+        ScaffoldCheck scaffoldCheck = (ScaffoldCheck) plugin.getCheckManager().getCheck("Scaffold");
+        if (scaffoldCheck != null && scaffoldCheck.checkScaffold(player, event.getBlockPlaced(), data)) {
+            if (!scaffoldCheck.isBypassed(player)) {
+                plugin.getViolationManager().addViolation(player, "Scaffold", 1.0);
+                plugin.getPunishmentManager().evaluate(player, "Scaffold");
+            }
+        }
+    }
+
+    @EventHandler
+    public void onPlayerItemConsume(PlayerItemConsumeEvent event) {
+        Player player = event.getPlayer();
+        
+        // Early-return for players with global bypass only.
+        // Category and per-check bypass is enforced inside Check.flag() and isBypassed() guards.
+        if (player.hasPermission("xac.bypass")) return;
+        
+        // Get player data
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        
+        // Check if it's food using Paper API
+        if (!event.getItem().getType().isEdible()) return;
+        
+        // Run fasteat check
+        FastEatCheck fastEatCheck = (FastEatCheck) plugin.getCheckManager().getCheck("FastEat");
+        if (fastEatCheck != null && fastEatCheck.checkFastEat(player, data, System.currentTimeMillis())) {
+            if (!fastEatCheck.isBypassed(player)) {
+                plugin.getViolationManager().addViolation(player, "FastEat", 1.0);
+                plugin.getPunishmentManager().evaluate(player, "FastEat");
+            }
+        }
+    }
+
+    @EventHandler
+    public void onInventoryOpen(InventoryOpenEvent event) {
+        if (!(event.getPlayer() instanceof Player player)) return;
+        
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        data.setInventoryOpen(true);
+    }
+
+    @EventHandler
+    public void onInventoryClose(InventoryCloseEvent event) {
+        if (!(event.getPlayer() instanceof Player player)) return;
+        
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        data.setInventoryOpen(false);
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onEntityDamage(EntityDamageEvent event) {
+        if (event.getCause() != EntityDamageEvent.DamageCause.FALL) return;
+        if (!(event.getEntity() instanceof Player player)) return;
+        // Early-return for players with global bypass only.
+        // Category and per-check bypass is enforced inside Check.flag() and isBypassed() guards.
+        if (player.hasPermission("xac.bypass")) return;
+
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        double expected = data.getLastExpectedFallDamage();
+        if (expected <= 0) return;
+
+        if (event.getFinalDamage() < expected * 0.5) {
+            Check noFallCheck = plugin.getCheckManager().getCheck("NoFall");
+            if (noFallCheck == null || !noFallCheck.isBypassed(player)) {
+                plugin.getViolationManager().addViolation(player, "NoFall", 1.0);
+                plugin.getPunishmentManager().evaluate(player, "NoFall");
+            }
+        }
+        data.setLastExpectedFallDamage(0.0);
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onEntityDamageByEntity(EntityDamageByEntityEvent event) {
+        if (!(event.getDamager() instanceof Player player)) return;
+        // Early-return for players with global bypass only.
+        // Category and per-check bypass is enforced inside Check.flag() and isBypassed() guards.
+        if (player.hasPermission("xac.bypass")) return;
+
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        data.setLastKnockbackTime(System.currentTimeMillis());
+    }
+
+    @EventHandler
+    public void onPlayerInteract(PlayerInteractEvent event) {
+        if (event.getAction() != org.bukkit.event.block.Action.RIGHT_CLICK_AIR && 
+            event.getAction() != org.bukkit.event.block.Action.RIGHT_CLICK_BLOCK) return;
+        if (!(event.getPlayer() instanceof Player player)) return;
+        // Early-return for players with global bypass only.
+        // Category and per-check bypass is enforced inside Check.flag() and isBypassed() guards.
+        if (player.hasPermission("xac.bypass")) return;
+
+        var item = event.getItem();
+        if (item == null || !item.getType().isEdible()) return;
+
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        data.setLastStartedEatingTime(System.currentTimeMillis());
+    }
+
+    @EventHandler
+    public void onPlayerRespawn(PlayerRespawnEvent event) {
+        Player player = event.getPlayer();
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        if (data == null) return;
+        data.clearServerVelocity();
+        data.clearPositionHistory();
+    }
+}

src/main/java/com/xeroth/xeroanticheat/listener/MovementListener.java

@@ -0,0 +1,139 @@
+package com.xeroth.xeroanticheat.listener;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import com.xeroth.xeroanticheat.manager.ViolationManager;
+import org.bukkit.Material;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.event.player.PlayerMoveEvent;
+import org.bukkit.event.player.PlayerQuitEvent;
+import org.bukkit.event.player.PlayerTeleportEvent;
+import org.bukkit.event.player.PlayerToggleFlightEvent;
+
+/**
+ * MovementListener - Handles movement-related events for anti-cheat checks.
+ */
+public class MovementListener implements Listener {
+
+    private final XeroAntiCheat plugin;
+
+    public MovementListener(XeroAntiCheat plugin) {
+        this.plugin = plugin;
+    }
+
+    @EventHandler
+    public void onPlayerJoin(PlayerJoinEvent event) {
+        Player player = event.getPlayer();
+        
+        // Create player data on join
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        
+        // Initialize position
+        data.addPosition(
+            player.getLocation().getX(),
+            player.getLocation().getY(),
+            player.getLocation().getZ(),
+            player.isOnGround()
+        );
+        
+        // Initialize rotation
+        data.addRotation(
+            player.getLocation().getYaw(),
+            player.getLocation().getPitch()
+        );
+    }
+
+    @EventHandler
+    public void onPlayerQuit(PlayerQuitEvent event) {
+        Player player = event.getPlayer();
+        
+        // Remove player data on quit
+        plugin.getViolationManager().removePlayer(player.getUniqueId());
+    }
+
+    @EventHandler(priority = EventPriority.LOW)
+    public void onPlayerMove(PlayerMoveEvent event) {
+        Player player = event.getPlayer();
+        
+        // Early-return for players with global bypass only.
+        // Category and per-check bypass is enforced inside Check.flag() and isBypassed() guards.
+        if (player.hasPermission("xac.bypass")) return;
+        
+        // Only check if position actually changed
+        if (!event.hasChangedPosition()) return;
+        
+        // Get player data
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        
+        // Store previous onGround state
+        boolean wasOnGround = data.isLastOnGround();
+        data.setLastOnGround(player.isOnGround());
+        
+        // Update position history
+        data.addPosition(
+            event.getTo().getX(),
+            event.getTo().getY(),
+            event.getTo().getZ(),
+            player.isOnGround()
+        );
+        
+        // Update rotation history
+        data.addRotation(
+            event.getTo().getYaw(),
+            event.getTo().getPitch()
+        );
+        
+        // Update wasAirborne
+        if (!player.isOnGround()) {
+            data.setWasAirborne(true);
+            data.incrementAirTicks();
+        } else {
+            data.setWasAirborne(false);
+            data.resetAirTicks();
+        }
+        
+        // Check ice at feet
+        Material blockBelow = event.getTo().clone().subtract(0, 1, 0).getBlock().getType();
+        data.setOnIce(blockBelow == Material.ICE || blockBelow == Material.PACKED_ICE || blockBelow == Material.FROSTED_ICE);
+        
+        // Update ping
+        data.setPing(player.getPing());
+        
+        // Run movement checks
+        plugin.getCheckManager().runCheck("Speed", data, player);
+        plugin.getCheckManager().runCheck("Fly", data, player);
+        plugin.getCheckManager().runCheck("Jesus", data, player);
+        plugin.getCheckManager().runCheck("NoFall", data, player);
+        plugin.getCheckManager().runCheck("Timer", data, player);
+        plugin.getCheckManager().runCheck("Spider", data, player);
+        plugin.getCheckManager().runCheck("Glide", data, player);
+        plugin.getCheckManager().runCheck("Phase", data, player);
+        plugin.getCheckManager().runCheck("Velocity", data, player);
+        plugin.getCheckManager().runCheck("InventoryMove", data, player);
+    }
+
+    @EventHandler
+    public void onPlayerToggleFlight(PlayerToggleFlightEvent event) {
+        Player player = event.getPlayer();
+        
+        // Update gliding state
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        data.setLastWasGliding(player.isGliding());
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onPlayerTeleport(PlayerTeleportEvent event) {
+        Player player = event.getPlayer();
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        if (data == null) return;
+
+        data.clearPositionHistory();
+        data.resetAirTicks();
+        data.clearServerVelocity();
+        data.setLastPlacementYaw(Float.NaN);
+    }
+}

src/main/java/com/xeroth/xeroanticheat/manager/CheckManager.java

@@ -0,0 +1,94 @@
+package com.xeroth.xeroanticheat.manager;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Manages registration and execution of all checks.
+ */
+public class CheckManager {
+
+    private final XeroAntiCheat plugin;
+    
+    private final Map<String, Check> checksByName = new HashMap<>();
+    private final List<Check> registeredChecks = new ArrayList<>();
+
+    public CheckManager(XeroAntiCheat plugin) {
+        this.plugin = plugin;
+    }
+
+    /**
+     * Register a check
+     */
+    public void registerCheck(Check check) {
+        String name = check.getName().toLowerCase();
+        checksByName.put(name, check);
+        registeredChecks.add(check);
+        plugin.getLogger().info("Registered check: " + check.getName());
+    }
+
+    /**
+     * Get a check by name
+     */
+    public Check getCheck(String name) {
+        return checksByName.get(name.toLowerCase());
+    }
+
+    /**
+     * Run a specific check
+     */
+    public void runCheck(String checkName, PlayerData data, Player player) {
+        Check check = checksByName.get(checkName.toLowerCase());
+        if (check != null && check.isEnabled()) {
+            check.check(data, player);
+        }
+    }
+
+    /**
+     * Get all registered checks
+     */
+    public List<Check> getRegisteredChecks() {
+        return new ArrayList<>(registeredChecks);
+    }
+
+    /**
+     * Get all enabled checks
+     */
+    public List<Check> getEnabledChecks() {
+        return registeredChecks.stream()
+            .filter(Check::isEnabled)
+            .toList();
+    }
+
+    /**
+     * Reload all checks (re-read config)
+     */
+    public void reloadChecks() {
+        for (Check check : registeredChecks) {
+            // Re-check enabled state from config
+            String path = "checks." + check.getName().toLowerCase() + ".enabled";
+            boolean enabled = plugin.getConfigManager().getBoolean(path, true);
+            check.setEnabled(enabled);
+        }
+        plugin.getLogger().info("Reloaded " + registeredChecks.size() + " checks");
+    }
+
+    /**
+     * Get check by class name
+     */
+    public Check getCheckByClass(Class<? extends Check> clazz) {
+        for (Check check : registeredChecks) {
+            if (check.getClass().equals(clazz)) {
+                return check;
+            }
+        }
+        return null;
+    }
+}

src/main/java/com/xeroth/xeroanticheat/manager/ConfigManager.java

@@ -0,0 +1,297 @@
+package com.xeroth.xeroanticheat.manager;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import org.bukkit.configuration.file.FileConfiguration;
+import org.bukkit.configuration.file.YamlConfiguration;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.logging.Level;
+
+/**
+ * Manages plugin configuration with validation and type-safe getters.
+ */
+public class ConfigManager {
+
+    private final XeroAntiCheat plugin;
+    private FileConfiguration config;
+    private File configFile;
+    
+    private static final Map<String, Object> DEFAULTS = new HashMap<>();
+    
+    static {
+        // General
+        DEFAULTS.put("enabled", true);
+        DEFAULTS.put("debug", false);
+        DEFAULTS.put("async_task_threads", 2);
+        
+        // Violation
+        DEFAULTS.put("violation.decay_interval", 30);
+        DEFAULTS.put("violation.decay_rate", 0.5);
+        
+        // Checks - Speed
+        DEFAULTS.put("checks.speed.enabled", true);
+        DEFAULTS.put("checks.speed.max_speed", 0.56);
+        DEFAULTS.put("checks.speed.ping_factor", 1.0);
+        DEFAULTS.put("checks.speed.buffer_ticks", 5);
+        DEFAULTS.put("checks.speed.warn_vl", 10);
+        DEFAULTS.put("checks.speed.kick_vl", 25);
+        DEFAULTS.put("checks.speed.tempban_vl", 50);
+        DEFAULTS.put("checks.speed.permban_vl", 100);
+        
+        // Checks - Fly
+        DEFAULTS.put("checks.fly.enabled", true);
+        DEFAULTS.put("checks.fly.fall_buffer", 10);
+        DEFAULTS.put("checks.fly.ground_desync_threshold", 3);
+        DEFAULTS.put("checks.fly.warn_vl", 10);
+        DEFAULTS.put("checks.fly.kick_vl", 25);
+        DEFAULTS.put("checks.fly.tempban_vl", 50);
+        DEFAULTS.put("checks.fly.permban_vl", 100);
+        
+        // Checks - Jesus
+        DEFAULTS.put("checks.jesus.enabled", true);
+        DEFAULTS.put("checks.jesus.warn_vl", 10);
+        DEFAULTS.put("checks.jesus.kick_vl", 25);
+        DEFAULTS.put("checks.jesus.tempban_vl", 50);
+        DEFAULTS.put("checks.jesus.permban_vl", 100);
+        
+        // Checks - NoFall
+        DEFAULTS.put("checks.nofall.enabled", true);
+        DEFAULTS.put("checks.nofall.min_fall_distance", 3);
+        DEFAULTS.put("checks.nofall.warn_vl", 10);
+        DEFAULTS.put("checks.nofall.kick_vl", 25);
+        DEFAULTS.put("checks.nofall.tempban_vl", 50);
+        DEFAULTS.put("checks.nofall.permban_vl", 100);
+        
+        // Checks - Timer
+        DEFAULTS.put("checks.timer.enabled", true);
+        DEFAULTS.put("checks.timer.max_packets_per_second", 22);
+        DEFAULTS.put("checks.timer.blink_threshold_ms", 500);
+        DEFAULTS.put("checks.timer.warn_vl", 10);
+        DEFAULTS.put("checks.timer.kick_vl", 25);
+        DEFAULTS.put("checks.timer.tempban_vl", 50);
+        DEFAULTS.put("checks.timer.permban_vl", 100);
+        
+        // Checks - Spider
+        DEFAULTS.put("checks.spider.enabled", true);
+        DEFAULTS.put("checks.spider.warn_vl", 10);
+        DEFAULTS.put("checks.spider.kick_vl", 25);
+        DEFAULTS.put("checks.spider.tempban_vl", 50);
+        DEFAULTS.put("checks.spider.permban_vl", 100);
+        
+        // Checks - Glide
+        DEFAULTS.put("checks.glide.enabled", true);
+        DEFAULTS.put("checks.glide.min_horizontal_speed", 0.5);
+        DEFAULTS.put("checks.glide.max_y_decrease", 0.1);
+        DEFAULTS.put("checks.glide.warn_vl", 10);
+        DEFAULTS.put("checks.glide.kick_vl", 25);
+        DEFAULTS.put("checks.glide.tempban_vl", 50);
+        DEFAULTS.put("checks.glide.permban_vl", 100);
+        
+        // Checks - KillAura
+        DEFAULTS.put("checks.killaura.enabled", true);
+        DEFAULTS.put("checks.killaura.max_angle", 100);
+        DEFAULTS.put("checks.killaura.max_rotation_change", 45);
+        DEFAULTS.put("checks.killaura.multitarget_window_ms", 100);
+        DEFAULTS.put("checks.killaura.warn_vl", 10);
+        DEFAULTS.put("checks.killaura.kick_vl", 25);
+        DEFAULTS.put("checks.killaura.tempban_vl", 50);
+        DEFAULTS.put("checks.killaura.permban_vl", 100);
+        
+        // Checks - Reach
+        DEFAULTS.put("checks.reach.enabled", true);
+        DEFAULTS.put("checks.reach.max_reach", 3.2);
+        DEFAULTS.put("checks.reach.creative_max_reach", 5.0);
+        DEFAULTS.put("checks.reach.ping_factor", 1.0);
+        DEFAULTS.put("checks.reach.warn_vl", 10);
+        DEFAULTS.put("checks.reach.kick_vl", 25);
+        DEFAULTS.put("checks.reach.tempban_vl", 50);
+        DEFAULTS.put("checks.reach.permban_vl", 100);
+        
+        // Checks - Critical
+        DEFAULTS.put("checks.critical.enabled", true);
+        DEFAULTS.put("checks.critical.allow_jump_crits", true);
+        DEFAULTS.put("checks.critical.warn_vl", 10);
+        DEFAULTS.put("checks.critical.kick_vl", 25);
+        DEFAULTS.put("checks.critical.tempban_vl", 50);
+        DEFAULTS.put("checks.critical.permban_vl", 100);
+        
+        // Checks - AutoClicker
+        DEFAULTS.put("checks.autoclicker.enabled", true);
+        DEFAULTS.put("checks.autoclicker.max_cps", 20);
+        DEFAULTS.put("checks.autoclicker.min_variance", 2.0);
+        DEFAULTS.put("checks.autoclicker.warn_vl", 10);
+        DEFAULTS.put("checks.autoclicker.kick_vl", 25);
+        DEFAULTS.put("checks.autoclicker.tempban_vl", 50);
+        DEFAULTS.put("checks.autoclicker.permban_vl", 100);
+        
+        // Checks - FastPlace
+        DEFAULTS.put("checks.fastplace.enabled", true);
+        DEFAULTS.put("checks.fastplace.max_blocks_per_second", 20);
+        DEFAULTS.put("checks.fastplace.warn_vl", 10);
+        DEFAULTS.put("checks.fastplace.kick_vl", 25);
+        DEFAULTS.put("checks.fastplace.tempban_vl", 50);
+        DEFAULTS.put("checks.fastplace.permban_vl", 100);
+        
+        // Checks - Scaffold
+        DEFAULTS.put("checks.scaffold.enabled", true);
+        DEFAULTS.put("checks.scaffold.min_pitch", 75);
+        DEFAULTS.put("checks.scaffold.signals_required", 2);
+        DEFAULTS.put("checks.scaffold.warn_vl", 10);
+        DEFAULTS.put("checks.scaffold.kick_vl", 25);
+        DEFAULTS.put("checks.scaffold.tempban_vl", 50);
+        DEFAULTS.put("checks.scaffold.permban_vl", 100);
+        
+        // Checks - FastEat
+        DEFAULTS.put("checks.fasteat.enabled", true);
+        DEFAULTS.put("checks.fasteat.max_eat_ticks", 32);
+        DEFAULTS.put("checks.fasteat.warn_vl", 10);
+        DEFAULTS.put("checks.fasteat.kick_vl", 25);
+        DEFAULTS.put("checks.fasteat.tempban_vl", 50);
+        DEFAULTS.put("checks.fasteat.permban_vl", 100);
+        
+        // Checks - InventoryMove
+        DEFAULTS.put("checks.inventorymove.enabled", true);
+        DEFAULTS.put("checks.inventorymove.warn_vl", 10);
+        DEFAULTS.put("checks.inventorymove.kick_vl", 25);
+        DEFAULTS.put("checks.inventorymove.tempban_vl", 50);
+        DEFAULTS.put("checks.inventorymove.permban_vl", 100);
+        
+        // Punishments
+        DEFAULTS.put("punishments.kick_command", "kick %player% &c[XAC] Illegal activity detected");
+        DEFAULTS.put("punishments.tempban_command", "tempban %player% 30d %reason%");
+        DEFAULTS.put("punishments.permban_command", "ban %player% %reason%");
+        DEFAULTS.put("punishments.default_reason", "[XeroAntiCheat] Suspicious activity");
+        
+        // Alerts
+        DEFAULTS.put("alerts.enabled", true);
+        DEFAULTS.put("alerts.format", "<dark_red>[<red>XAC<dark_red>] <white>%player% <red>failed <white>%check% <red>(VL: <white>%vl%<red>)");
+        DEFAULTS.put("alerts.staff_format", "<gray>[%time%] %message%");
+        
+        // Commands
+        DEFAULTS.put("commands.reload_permission", "xac.admin");
+        DEFAULTS.put("commands.bypass_permission", "xac.bypass");
+        DEFAULTS.put("commands.alerts_permission", "xac.alerts");
+        
+        // TPS
+        DEFAULTS.put("tps.enabled", true);
+        DEFAULTS.put("tps.min_tps_threshold", 18.0);
+    }
+
+    public ConfigManager(XeroAntiCheat plugin) {
+        this.plugin = plugin;
+    }
+
+    /**
+     * Load or reload the configuration file
+     */
+    public void loadConfig() {
+        configFile = new File(plugin.getDataFolder(), "config.yml");
+        
+        if (!configFile.exists()) {
+            plugin.getDataFolder().mkdirs();
+            try (InputStream in = plugin.getResource("config.yml")) {
+                if (in != null) {
+                    Files.copy(in, configFile.toPath());
+                }
+            } catch (IOException e) {
+                plugin.getLogger().log(Level.SEVERE, "Could not create default config", e);
+            }
+        }
+        
+        config = YamlConfiguration.loadConfiguration(configFile);
+        
+        // Apply defaults
+        for (Map.Entry<String, Object> entry : DEFAULTS.entrySet()) {
+            if (config.get(entry.getKey()) == null) {
+                config.set(entry.getKey(), entry.getValue());
+            }
+        }
+        
+        // Save if new keys were added
+        try {
+            config.save(configFile);
+        } catch (IOException e) {
+            plugin.getLogger().log(Level.SEVERE, "Could not save config", e);
+        }
+        
+        validateConfig();
+    }
+
+    /**
+     * Validate configuration values
+     */
+    private void validateConfig() {
+        // Check for invalid values and log warnings
+        if (config.getDouble("checks.speed.max_speed", 0.0) <= 0.0) {
+            plugin.getLogger().warning("Invalid checks.speed.max_speed, using default 0.56");
+            config.set("checks.speed.max_speed", 0.56);
+        }
+        
+        if (config.getInt("violation.decay_interval", 0) <= 0) {
+            plugin.getLogger().warning("Invalid violation.decay_interval, using default 30");
+            config.set("violation.decay_interval", 30);
+        }
+    }
+
+    // Type-safe getters
+    
+    public boolean getBoolean(String path, boolean defaultValue) {
+        return config.getBoolean(path, defaultValue);
+    }
+
+    public boolean getBoolean(String path) {
+        return config.getBoolean(path, DEFAULTS.containsKey(path) && DEFAULTS.get(path) instanceof Boolean 
+            ? (Boolean) DEFAULTS.get(path) : false);
+    }
+
+    public int getInt(String path, int defaultValue) {
+        return config.getInt(path, defaultValue);
+    }
+
+    public int getInt(String path) {
+        return config.getInt(path, DEFAULTS.containsKey(path) && DEFAULTS.get(path) instanceof Integer 
+            ? (Integer) DEFAULTS.get(path) : 0);
+    }
+
+    public double getDouble(String path, double defaultValue) {
+        return config.getDouble(path, defaultValue);
+    }
+
+    public double getDouble(String path) {
+        return config.getDouble(path, DEFAULTS.containsKey(path) && DEFAULTS.get(path) instanceof Double 
+            ? (Double) DEFAULTS.get(path) : 0.0);
+    }
+
+    public String getString(String path) {
+        return config.getString(path, DEFAULTS.containsKey(path) ? String.valueOf(DEFAULTS.get(path)) : "");
+    }
+
+    public String getString(String path, String defaultValue) {
+        return config.getString(path, defaultValue);
+    }
+
+    public FileConfiguration getConfig() {
+        return config;
+    }
+
+    public boolean isEnabled() {
+        return getBoolean("enabled", true);
+    }
+
+    public boolean isDebug() {
+        return getBoolean("debug", false);
+    }
+
+    public String getAlertsFormat() {
+        return getString("alerts.format");
+    }
+
+    public boolean isAlertsEnabled() {
+        return getBoolean("alerts.enabled", true);
+    }
+}

src/main/java/com/xeroth/xeroanticheat/manager/DatabaseManager.java

@@ -0,0 +1,90 @@
+package com.xeroth.xeroanticheat.manager;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+
+import java.io.File;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.util.logging.Level;
+
+public class DatabaseManager {
+
+    private final XeroAntiCheat plugin;
+    private Connection connection;
+
+    private static final String CREATE_TABLE = """
+        CREATE TABLE IF NOT EXISTS punishments (
+            id          INTEGER PRIMARY KEY AUTOINCREMENT,
+            timestamp   TEXT    NOT NULL,
+            type        TEXT    NOT NULL,
+            player_uuid TEXT    NOT NULL,
+            player_name TEXT    NOT NULL,
+            check_name  TEXT    NOT NULL,
+            vl          REAL    NOT NULL
+        )
+        """;
+
+    private static final String INSERT = """
+        INSERT INTO punishments (timestamp, type, player_uuid, player_name, check_name, vl)
+        VALUES (?, ?, ?, ?, ?, ?)
+        """;
+
+    public DatabaseManager(XeroAntiCheat plugin) {
+        this.plugin = plugin;
+    }
+
+    public void initialize() {
+        try {
+            File dbFile = new File(plugin.getDataFolder(), "data.db");
+            plugin.getDataFolder().mkdirs();
+            String url = "jdbc:sqlite:" + dbFile.getAbsolutePath();
+            connection = DriverManager.getConnection(url);
+
+            try (var stmt = connection.createStatement()) {
+                stmt.execute(CREATE_TABLE);
+            }
+            plugin.getLogger().info("SQLite database initialized.");
+        } catch (SQLException e) {
+            plugin.getLogger().log(Level.SEVERE, "Failed to initialize SQLite database", e);
+            connection = null;
+        }
+    }
+
+    public synchronized void insertPunishment(
+            String timestamp, String type,
+            String playerUuid, String playerName,
+            String checkName, double vl) {
+
+        if (connection == null) return;
+
+        try (PreparedStatement ps = connection.prepareStatement(INSERT)) {
+            ps.setString(1, timestamp);
+            ps.setString(2, type);
+            ps.setString(3, playerUuid);
+            ps.setString(4, playerName);
+            ps.setString(5, checkName);
+            ps.setDouble(6, vl);
+            ps.executeUpdate();
+        } catch (SQLException e) {
+            plugin.getLogger().log(Level.WARNING, "Failed to insert punishment record", e);
+        }
+    }
+
+    public synchronized void close() {
+        if (connection != null) {
+            try {
+                connection.close();
+            } catch (SQLException e) {
+                plugin.getLogger().log(Level.WARNING, "Failed to close SQLite connection", e);
+            } finally {
+                connection = null;
+            }
+        }
+    }
+
+    public boolean isAvailable() {
+        return connection != null;
+    }
+}

src/main/java/com/xeroth/xeroanticheat/manager/PunishmentManager.java

@@ -0,0 +1,217 @@
+package com.xeroth.xeroanticheat.manager;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.minimessage.MiniMessage;
+import org.bukkit.Bukkit;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Set;
+import java.util.UUID;
+import java.util.logging.Level;
+
+/**
+ * Handles punishment execution and logging.
+ */
+public class PunishmentManager {
+
+    private final XeroAntiCheat plugin;
+    private final ViolationManager violationManager;
+    
+    private final MiniMessage miniMessage = MiniMessage.miniMessage();
+    private SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+    
+    private File logsFolder;
+    private File punishmentsLog;
+
+    public PunishmentManager(XeroAntiCheat plugin, ViolationManager violationManager) {
+        this.plugin = plugin;
+        this.violationManager = violationManager;
+        initializeLogs();
+    }
+
+    private void initializeLogs() {
+        logsFolder = new File(plugin.getDataFolder(), "logs");
+        if (!logsFolder.exists()) {
+            logsFolder.mkdirs();
+        }
+        
+        punishmentsLog = new File(logsFolder, "punishments.log");
+        if (!punishmentsLog.exists()) {
+            try {
+                punishmentsLog.createNewFile();
+            } catch (IOException e) {
+                plugin.getLogger().log(Level.SEVERE, "Could not create punishments log", e);
+            }
+        }
+    }
+
+    /**
+     * Evaluate violations and apply appropriate punishment
+     */
+    public void evaluate(Player player, String checkName) {
+        if (!plugin.getConfigManager().isEnabled()) return;
+        
+        PlayerData data = violationManager.getPlayerData(player);
+        if (data == null) return;
+        
+        double vl = data.getViolationLevel(checkName);
+        
+        String checkPath = "checks." + checkName.toLowerCase() + ".";
+        
+        int warnVl = plugin.getConfigManager().getInt(checkPath + "warn_vl", 10);
+        int kickVl = plugin.getConfigManager().getInt(checkPath + "kick_vl", 25);
+        int tempbanVl = plugin.getConfigManager().getInt(checkPath + "tempban_vl", 50);
+        int permbanVl = plugin.getConfigManager().getInt(checkPath + "permban_vl", 100);
+        
+        Check check = plugin.getCheckManager().getCheck(checkName);
+        String category = check != null ? check.getCategory() : "misc";
+        
+        sendAlert(player, checkName, vl, category);
+        
+        if (vl >= permbanVl) {
+            punish(player, checkName, "PERMBAN", permbanVl);
+        } else if (vl >= tempbanVl) {
+            punish(player, checkName, "TEMPBAN", tempbanVl);
+        } else if (vl >= kickVl) {
+            punish(player, checkName, "KICK", kickVl);
+        } else if (vl >= warnVl) {
+            warn(player, checkName);
+        }
+    }
+
+    /**
+     * Send warning to player
+     */
+    private void warn(Player player, String checkName) {
+        Component message = miniMessage.deserialize(
+            "<red>Warning: <white>Suspicious behavior detected (" + checkName + ")"
+        );
+        player.sendMessage(message);
+    }
+
+    /**
+     * Apply punishment based on type
+     */
+    private void punish(Player player, String checkName, String type, double vl) {
+        String reason = plugin.getConfigManager().getString("punishments.default_reason", "Suspicious activity");
+        String playerName = player.getName();
+        
+        switch (type) {
+            case "KICK" -> {
+                String kickCmd = plugin.getConfigManager().getString("punishments.kick_command", 
+                    "kick %player% &c[XAC] Illegal activity detected");
+                kickCmd = kickCmd.replace("%player%", playerName).replace("%reason%", reason);
+                executeCommand(kickCmd);
+                logPunishment(type, player, checkName, vl);
+            }
+            case "TEMPBAN" -> {
+                String tempbanCmd = plugin.getConfigManager().getString("punishments.tempban_command",
+                    "tempban %player% 30d %reason%");
+                tempbanCmd = tempbanCmd.replace("%player%", playerName).replace("%reason%", reason);
+                executeCommand(tempbanCmd);
+                logPunishment(type, player, checkName, vl);
+            }
+            case "PERMBAN" -> {
+                String permbanCmd = plugin.getConfigManager().getString("punishments.permban_command",
+                    "ban %player% %reason%");
+                permbanCmd = permbanCmd.replace("%player%", playerName).replace("%reason%", reason);
+                executeCommand(permbanCmd);
+                logPunishment(type, player, checkName, vl);
+            }
+        }
+    }
+
+    /**
+     * Execute a console command
+     */
+    private void executeCommand(String command) {
+        final String cmd = command.startsWith("/") ? command.substring(1) : command;
+        Bukkit.getScheduler().runTask(plugin, () -> {
+            Bukkit.dispatchCommand(Bukkit.getConsoleSender(), cmd);
+        });
+    }
+
+    /**
+     * Send alert to staff members
+     */
+    public void sendAlert(Player player, String checkName, double vl, String category) {
+        if (!plugin.getConfigManager().isAlertsEnabled()) return;
+        
+        String format = plugin.getConfigManager().getAlertsFormat();
+        format = format.replace("%player%", player.getName())
+                      .replace("%check%", checkName)
+                      .replace("%vl%", String.valueOf((int) vl))
+                      .replace("%category%", category);
+        
+        Component message = miniMessage.deserialize(format);
+        
+        String categoryPerm = "xac.alerts." + category;
+        
+        for (Player staff : Bukkit.getOnlinePlayers()) {
+            boolean hasPermission = staff.hasPermission("xac.alerts")
+                    || staff.hasPermission("xac.admin")
+                    || staff.hasPermission(categoryPerm);
+            if (!hasPermission) continue;
+            if (!plugin.isAlertsEnabled(staff.getUniqueId())) continue;
+            staff.sendMessage(message);
+        }
+        
+        plugin.getLogger().info(
+            player.getName() + " failed " + checkName
+            + " [" + category + "] (VL: " + (int) vl + ")"
+        );
+    }
+
+    /**
+     * Log punishment to file and database
+     */
+    private void logPunishment(String type, Player player, String checkName, double vl) {
+        final String timestamp = dateFormat.format(new Date());
+        final String playerName = player.getName();
+        final String playerUuid = player.getUniqueId().toString();
+
+        final String logLine = String.format("[%s] %s | %s | %s | %s | %.1f",
+            timestamp,
+            type,
+            playerName,
+            playerUuid,
+            checkName,
+            vl);
+
+        Bukkit.getScheduler().runTaskAsynchronously(plugin, () -> {
+            try (FileWriter fw = new FileWriter(punishmentsLog, true);
+                 PrintWriter pw = new PrintWriter(fw)) {
+                pw.println(logLine);
+            } catch (IOException e) {
+                plugin.getLogger().log(Level.WARNING, "Could not write to punishments log", e);
+            }
+
+            DatabaseManager db = plugin.getDatabaseManager();
+            if (db != null && db.isAvailable()) {
+                db.insertPunishment(timestamp, type, playerUuid, playerName, checkName, vl);
+            }
+        });
+    }
+
+    /**
+     * Manually punish a player for a check
+     */
+    public void manualPunish(Player player, String checkName) {
+        PlayerData data = violationManager.getPlayerData(player);
+        if (data == null) return;
+        
+        // Set VL to kick threshold and evaluate
+        data.setViolationLevel(checkName, plugin.getConfigManager().getInt("checks." + checkName.toLowerCase() + ".kick_vl", 25));
+        evaluate(player, checkName);
+    }
+}

src/main/java/com/xeroth/xeroanticheat/manager/ViolationManager.java

@@ -0,0 +1,158 @@
+package com.xeroth.xeroanticheat.manager;
+
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.minimessage.MiniMessage;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Manages violation levels for all players and checks.
+ * Thread-safe implementation with temporal decay support.
+ */
+public class ViolationManager {
+
+    private final XeroAntiCheat plugin;
+    
+    private final Map<UUID, PlayerData> playerDataCache = new ConcurrentHashMap<>();
+    private final MiniMessage miniMessage = MiniMessage.miniMessage();
+    
+    private double decayRate;
+
+    public ViolationManager(XeroAntiCheat plugin) {
+        this.plugin = plugin;
+        this.decayRate = plugin.getConfigManager().getDouble("violation.decay_rate", 0.5);
+    }
+
+    /**
+     * Get or create player data for a player
+     */
+    public PlayerData getPlayerData(Player player) {
+        return playerDataCache.computeIfAbsent(player.getUniqueId(), k -> new PlayerData(player));
+    }
+
+    /**
+     * Get player data by UUID
+     */
+    public PlayerData getPlayerData(UUID uuid) {
+        return playerDataCache.get(uuid);
+    }
+
+    /**
+     * Add violation to a player for a specific check
+     */
+    public void addViolation(Player player, String checkName, double weight) {
+        PlayerData data = getPlayerData(player);
+        if (data == null) return;
+        
+        data.incrementViolation(checkName, weight);
+        
+        data.setLastFlaggedCheck(checkName);
+        data.setLastFlagTime(System.currentTimeMillis());
+
+        double newVl = data.getViolationLevel(checkName);
+
+        if (plugin.isVerboseTarget(player.getUniqueId())) {
+            Component verbose = miniMessage.deserialize(
+                "<gray>[<white>VERBOSE<gray>] <yellow>" + player.getName()
+                + " <gray>» <white>" + checkName
+                + " <gray>+<green>" + String.format("%.1f", weight)
+                + " <gray>(VL: <white>" + String.format("%.1f", newVl) + "<gray>)"
+            );
+            for (Player staff : Bukkit.getOnlinePlayers()) {
+                if (staff.hasPermission("xac.command.verbose") || staff.hasPermission("xac.admin")) {
+                    staff.sendMessage(verbose);
+                }
+            }
+        }
+        
+        if (plugin.getConfigManager().isDebug()) {
+            plugin.getLogger().info(player.getName() + " violated " + checkName + " (VL: " + newVl + ")");
+        }
+    }
+
+    /**
+     * Get violation level for a player and check
+     */
+    public double getViolationLevel(Player player, String checkName) {
+        PlayerData data = getPlayerData(player);
+        if (data == null) return 0.0;
+        return data.getViolationLevel(checkName);
+    }
+
+    /**
+     * Decay all violation levels for all players
+     */
+    public void decayAll() {
+        decayRate = plugin.getConfigManager().getDouble("violation.decay_rate", 0.5);
+        
+        for (PlayerData data : playerDataCache.values()) {
+            for (String checkName : data.getViolationLevels().keySet()) {
+                data.decayViolation(checkName, decayRate);
+            }
+        }
+    }
+
+    /**
+     * Clear all violation levels for a player
+     */
+    public void clearPlayer(UUID uuid) {
+        playerDataCache.remove(uuid);
+    }
+
+    /**
+     * Clear all violation levels for all players
+     */
+    public void clearAll() {
+        playerDataCache.clear();
+    }
+
+    /**
+     * Remove player data on quit
+     */
+    public void removePlayer(UUID uuid) {
+        playerDataCache.remove(uuid);
+    }
+
+    /**
+     * Save all pending data (for shutdown)
+     */
+    public void saveAll() {
+        // Currently just clearing, but could be extended to persist to disk
+        if (plugin.getConfigManager().isDebug()) {
+            plugin.getLogger().info("Saved " + playerDataCache.size() + " player data records");
+        }
+    }
+
+    /**
+     * Check if a player has any violations above threshold
+     */
+    public boolean hasViolations(Player player, double threshold) {
+        PlayerData data = getPlayerData(player);
+        if (data == null) return false;
+        
+        for (double vl : data.getViolationLevels().values()) {
+            if (vl >= threshold) return true;
+        }
+        return false;
+    }
+
+    /**
+     * Get total violations for a player
+     */
+    public double getTotalViolations(Player player) {
+        PlayerData data = getPlayerData(player);
+        if (data == null) return 0.0;
+        
+        double total = 0.0;
+        for (double vl : data.getViolationLevels().values()) {
+            total += vl;
+        }
+        return total;
+    }
+}

src/main/java/com/xeroth/xeroanticheat/protocol/PacketListener.java

@@ -0,0 +1,213 @@
+package com.xeroth.xeroanticheat.protocol;
+
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.ProtocolLibrary;
+import com.comphenix.protocol.ProtocolManager;
+import com.comphenix.protocol.events.PacketAdapter;
+import com.comphenix.protocol.events.PacketEvent;
+import com.comphenix.protocol.events.ListenerPriority;
+import com.xeroth.xeroanticheat.XeroAntiCheat;
+import com.xeroth.xeroanticheat.check.Check;
+import com.xeroth.xeroanticheat.data.PlayerData;
+import org.bukkit.entity.Player;
+
+/**
+ * PacketListener - Handles ProtocolLib packet events for enhanced detection.
+ *
+ * This provides more accurate timing and data for:
+ * - TimerCheck (packet timing)
+ * - KillAuraCheck (rotation analysis)
+ * - AutoClickerCheck (click timing)
+ * - VelocityCheck (server velocity packets)
+ *
+ * Gracefully disabled if ProtocolLib is not present.
+ */
+public class PacketListener {
+
+    private final XeroAntiCheat plugin;
+    private ProtocolManager manager;
+    private boolean protocolLibAvailable = false;
+
+    public PacketListener(XeroAntiCheat plugin) {
+        this.plugin = plugin;
+    }
+
+    /**
+     * Register packet listeners if ProtocolLib is available
+     */
+    public void register() {
+        try {
+            manager = ProtocolLibrary.getProtocolManager();
+            protocolLibAvailable = true;
+
+            registerMovementAdapter();
+            registerArmAnimationAdapter();
+            registerVelocityAdapter();
+
+            plugin.getLogger().info("ProtocolLib detected - packet-level checks enabled");
+
+        } catch (Exception e) {
+            protocolLibAvailable = false;
+            plugin.getLogger().info("ProtocolLib not found - using event-based detection");
+        }
+    }
+
+    private void registerMovementAdapter() {
+        final XeroAntiCheat self = this.plugin;
+        manager.addPacketListener(new PacketAdapter(
+                plugin,
+                ListenerPriority.MONITOR,
+                PacketType.Play.Client.POSITION,
+                PacketType.Play.Client.POSITION_LOOK,
+                PacketType.Play.Client.LOOK) {
+            @Override
+            public void onPacketReceiving(PacketEvent event) {
+                Player player = event.getPlayer();
+                if (player == null || !player.isOnline()) return;
+
+                Check timerCheck = self.getCheckManager().getCheck("Timer");
+                if (timerCheck != null && timerCheck.isBypassed(player)) return;
+
+                PlayerData data = self.getViolationManager().getPlayerData(player);
+                if (data == null) return;
+
+                long now = System.currentTimeMillis();
+
+                if (now - data.getLastPacketCountReset() > 1000) {
+                    data.setPacketsThisSecond(0);
+                    data.setLastPacketCountReset(now);
+                }
+                data.incrementPacketsThisSecond();
+                data.setLastMovePacketTime(now);
+
+                PacketType type = event.getPacketType();
+                if (type == PacketType.Play.Client.POSITION_LOOK
+                        || type == PacketType.Play.Client.LOOK) {
+                    try {
+                        float yaw = event.getPacket().getFloat().read(0);
+                        float pitch = event.getPacket().getFloat().read(1);
+                        data.addRotation(yaw, pitch);
+                    } catch (Exception ignored) {
+                    }
+                }
+            }
+        });
+    }
+
+    private void registerArmAnimationAdapter() {
+        final XeroAntiCheat self = this.plugin;
+        manager.addPacketListener(new PacketAdapter(
+                plugin,
+                ListenerPriority.MONITOR,
+                PacketType.Play.Client.ARM_ANIMATION) {
+            @Override
+            public void onPacketReceiving(PacketEvent event) {
+                Player player = event.getPlayer();
+                if (player == null || !player.isOnline()) return;
+
+                Check autoClickerCheck = self.getCheckManager().getCheck("AutoClicker");
+                if (autoClickerCheck != null && autoClickerCheck.isBypassed(player)) return;
+
+                PlayerData data = self.getViolationManager().getPlayerData(player);
+                if (data != null) {
+                    data.addClick();
+                }
+            }
+        });
+    }
+
+    private void registerVelocityAdapter() {
+        final XeroAntiCheat self = this.plugin;
+        manager.addPacketListener(new PacketAdapter(
+                plugin,
+                ListenerPriority.MONITOR,
+                PacketType.Play.Server.ENTITY_VELOCITY) {
+            @Override
+            public void onPacketSending(PacketEvent event) {
+                Player player = event.getPlayer();
+                if (player == null || !player.isOnline()) return;
+
+                int entityId = event.getPacket().getIntegers().read(0);
+                if (entityId != player.getEntityId()) return;
+
+                Check velCheck = self.getCheckManager().getCheck("Velocity");
+                if (velCheck != null && velCheck.isBypassed(player)) return;
+
+                PlayerData data = self.getViolationManager().getPlayerData(player);
+                if (data == null) return;
+
+                double vx = event.getPacket().getIntegers().read(1) / 8000.0;
+                double vy = event.getPacket().getIntegers().read(2) / 8000.0;
+                double vz = event.getPacket().getIntegers().read(3) / 8000.0;
+
+                data.setLastServerVelocity(new org.bukkit.util.Vector(vx, vy, vz));
+            }
+        });
+    }
+
+    /**
+     * Check if ProtocolLib is available
+     */
+    public boolean isProtocolLibAvailable() {
+        return protocolLibAvailable;
+    }
+
+    /**
+     * Update packet timing (called from event listeners when ProtocolLib unavailable)
+     */
+    public void updatePacketTiming(Player player) {
+        if (protocolLibAvailable) {
+            return;
+        }
+
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        if (data == null) return;
+
+        long now = System.currentTimeMillis();
+        data.setLastMovePacketTime(now);
+
+        if (now - data.getLastPacketCountReset() > 1000) {
+            data.setPacketsThisSecond(0);
+            data.setLastPacketCountReset(now);
+        }
+        data.incrementPacketsThisSecond();
+    }
+
+    /**
+     * Record click (called from event listeners when ProtocolLib unavailable)
+     */
+    public void recordClick(Player player) {
+        if (protocolLibAvailable) {
+            return;
+        }
+
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        if (data != null) {
+            data.addClick();
+        }
+    }
+
+    /**
+     * Record attack (called from event listeners when ProtocolLib unavailable)
+     */
+    public void recordAttack(Player player, java.util.UUID entityUuid) {
+        if (protocolLibAvailable) {
+            return;
+        }
+
+        PlayerData data = plugin.getViolationManager().getPlayerData(player);
+        if (data != null) {
+            data.addAttack(entityUuid);
+            data.setLastAttackYaw(player.getLocation().getYaw());
+        }
+    }
+
+    /**
+     * Unregister all packet listeners
+     */
+    public void unregister() {
+        if (!protocolLibAvailable || manager == null) return;
+
+        manager.removePacketListeners(plugin);
+    }
+}

src/main/resources/config.yml

@@ -0,0 +1,339 @@
+# XeroAntiCheat Configuration File
+# Version: 1.0.0
+# Target: Paper 1.21.x (compatible with 1.20-1.22)
+
+# ==========================================
+# GENERAL SETTINGS
+# ==========================================
+
+# Enable or disable the anti-cheat
+enabled: true
+
+# Enable debug mode (logs additional information)
+debug: false
+
+# Number of async threads for background tasks
+async_task_threads: 2
+
+# Database settings
+database:
+  # Set to false to disable SQLite logging (flat-file log always active)
+  enabled: true
+
+# ==========================================
+# VIOLATION SYSTEM
+# ==========================================
+
+violation:
+  # Time in seconds between violation level decay
+  decay_interval: 30
+  
+  # Amount to reduce VL by each decay interval
+  decay_rate: 0.5
+
+# ==========================================
+# CHECK CONFIGURATION
+# ==========================================
+
+# Movement Checks
+checks:
+  # ----------------------------------------
+  # SPEED CHECK
+  # Detects horizontal movement faster than possible
+  # ----------------------------------------
+  speed:
+    enabled: true
+    # Base maximum speed (blocks per tick)
+    max_speed: 0.56
+    # Ping compensation factor (scales latency leniency)
+    ping_factor: 1.0
+    # Number of ticks to buffer for rolling average
+    buffer_ticks: 5
+    # VL thresholds
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # FLY CHECK
+  # Detects flying without elytra/creative/spectator
+  # ----------------------------------------
+  fly:
+    enabled: true
+    # Number of ticks to allow for stepping/slabs
+    fall_buffer: 10
+    # Maximum ground desync ticks before flagging
+    ground_desync_threshold: 3
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # JESUS CHECK (NoWaterWalk)
+  # Detects walking on water without Frost Walker
+  # ----------------------------------------
+  jesus:
+    enabled: true
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # NOFALL CHECK
+  # Detects no fall damage after falling >3 blocks
+  # ----------------------------------------
+  nofall:
+    enabled: true
+    # Minimum fall distance to track
+    min_fall_distance: 3
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # TIMER CHECK (Blink/Packet Timer)
+  # Detects packet timing anomalies
+  # ----------------------------------------
+  timer:
+    enabled: true
+    # Maximum packets per second allowed
+    max_packets_per_second: 22
+    # Milliseconds of no packets before flagging blink
+    blink_threshold_ms: 500
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # SPIDER CHECK
+  # Detects climbing non-climbable blocks
+  # ----------------------------------------
+  spider:
+    enabled: true
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # GLIDE CHECK (ElytraHack)
+  # Detects glide-like movement without elytra
+  # ----------------------------------------
+  glide:
+    enabled: true
+    # Minimum horizontal speed for glide detection
+    min_horizontal_speed: 0.5
+    # Maximum Y decrease per tick for glide curve
+    max_y_decrease: 0.1
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # KILLAURA CHECK
+  # Detects impossible combat angles/rotations
+  # ----------------------------------------
+  killaura:
+    enabled: true
+    # Maximum angle in degrees from look direction
+    max_angle: 100
+    # Maximum rotation change between attacks
+    max_rotation_change: 45
+    # Window for multi-target detection (ms)
+    multitarget_window_ms: 100
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # REACH CHECK
+  # Detects attacking beyond reach
+  # ----------------------------------------
+  reach:
+    enabled: true
+    # Maximum reach in blocks (survival)
+    max_reach: 3.2
+    # Maximum reach in blocks (creative)
+    creative_max_reach: 5.0
+    # Ping compensation factor
+    ping_factor: 1.0
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # CRITICAL CHECK
+  # Detects critical hits without being airborne
+  # ----------------------------------------
+  critical:
+    enabled: true
+    # Allow legitimate jump-crits
+    allow_jump_crits: true
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # AUTOCLICKER CHECK
+  # Detects excessive CPS or perfect patterns
+  # ----------------------------------------
+  autoclicker:
+    enabled: true
+    # Maximum clicks per second
+    max_cps: 20
+    # Minimum variance (lower = more suspicious)
+    min_variance: 2.0
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # FASTPLACE CHECK
+  # Detects block placement too fast
+  # ----------------------------------------
+  fastplace:
+    enabled: true
+    # Maximum blocks per second
+    max_blocks_per_second: 20
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # PHASE CHECK
+  # Detects players clipping through solid blocks
+  # ----------------------------------------
+  phase:
+    enabled: true
+    # Minimum movement distance before ray-cast runs (blocks)
+    min_distance: 0.5
+    # Maximum movement delta — larger values are treated as teleports
+    max_distance: 5.0
+    warn_vl: 5
+    kick_vl: 15
+    tempban_vl: 30
+    permban_vl: 60
+
+  # ----------------------------------------
+  # VELOCITY CHECK
+  # Detects players ignoring server-sent knockback (requires ProtocolLib)
+  # ----------------------------------------
+  velocity:
+    enabled: true
+    # Minimum server-sent velocity magnitude to check
+    min_expected_velocity: 0.15
+    # Player must move at least 20% of expected knockback
+    min_displacement_ratio: 0.2
+    warn_vl: 8
+    kick_vl: 20
+    tempban_vl: 40
+    permban_vl: 80
+
+  # ----------------------------------------
+  # SCAFFOLD CHECK
+  # Detects automated scaffolding
+  # ----------------------------------------
+  scaffold:
+    enabled: true
+    # Minimum pitch angle for suspicious placement
+    min_pitch: 75
+    # Number of signals required to flag
+    signals_required: 2
+    # Signal 4: Max yaw change (degrees) between placements
+    rotation_lock_threshold: 2.0
+    # Signal 4: Min horizontal speed (blocks/tick) required
+    min_move_speed: 0.15
+    # Signal 5: StdDev below this triggers signal (too-perfect timing)
+    min_placement_variance_ms: 30.0
+    # Signal 5: Min blocks/sec before signal 5 is evaluated
+    min_bps_for_variance_check: 5
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # FASTEAT CHECK
+  # Detects eating faster than possible
+  # ----------------------------------------
+  fasteat:
+    enabled: true
+    # Maximum eating duration in ticks (32 = 1.6s)
+    max_eat_ticks: 32
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+  # ----------------------------------------
+  # INVENTORYMOVE CHECK
+  # Detects movement while inventory open
+  # ----------------------------------------
+  inventorymove:
+    enabled: true
+    warn_vl: 10
+    kick_vl: 25
+    tempban_vl: 50
+    permban_vl: 100
+
+# ==========================================
+# PUNISHMENT SETTINGS
+# ==========================================
+
+punishments:
+  # Commands to execute for each punishment level
+  # Use %player% for player name, %reason% for reason
+  kick_command: "kick %player% &c[XAC] Illegal activity detected"
+  tempban_command: "tempban %player% 30d %reason%"
+  permban_command: "ban %player% %reason%"
+
+  # Default reason for bans
+  default_reason: "[XeroAntiCheat] Suspicious activity"
+
+# ==========================================
+# ALERT SYSTEM
+# ==========================================
+
+alerts:
+  # Enable or disable alert broadcasts
+  enabled: true
+  
+  # Alert format (MiniMessage)
+  # Available placeholders: %player%, %check%, %vl%
+  format: "<dark_red>[<red>XAC<dark_red>] <white>%player% <red>failed <white>%check% <red>(VL: <white>%vl%<red>)"
+  
+  # Staff-only alert format
+  staff_format: "<gray>[%time%] %message%"
+
+# ==========================================
+# COMMANDS
+# ==========================================
+
+commands:
+  # Permission required for admin commands
+  reload_permission: "xac.admin"
+  # Permission to bypass all checks
+  bypass_permission: "xac.bypass"
+  # Permission to receive alerts
+  alerts_permission: "xac.alerts"
+
+# ==========================================
+# TPS COMPENSATION
+# ==========================================
+
+tps:
+  # Enable TPS-based threshold scaling
+  enabled: true
+  # Minimum TPS to apply compensation
+  min_tps_threshold: 18.0

src/main/resources/plugin.yml

@@ -0,0 +1,185 @@
+name: XeroAntiCheat
+version: 1.0.7
+main: com.xeroth.xeroanticheat.XeroAntiCheat
+author: Xeroth
+description: Lightweight, accurate anti-cheat for Paper 1.21.x
+api-version: 1.21
+softdepend:
+  - ProtocolLib
+
+commands:
+  xac:
+    description: XeroAntiCheat main command
+    usage: /xac <reload|status|punish|clearviolations|verbose|alerts|version>
+    permission: xac.command.version
+    aliases: [xeroanticheat, anticheat]
+
+permissions:
+
+  # ── Wildcards ────────────────────────────────────────────────────────────
+
+  xac.*:
+    description: Grants all XeroAntiCheat permissions including bypass
+    default: false
+    children:
+      xac.admin: true
+      xac.bypass: true
+
+  xac.admin:
+    description: Grants all staff commands and alert access (does NOT grant bypass)
+    default: op
+    children:
+      xac.command.reload: true
+      xac.command.status: true
+      xac.command.punish: true
+      xac.command.clearviolations: true
+      xac.command.verbose: true
+      xac.command.alerts: true
+      xac.command.version: true
+      xac.alerts: true
+
+  # ── Commands ─────────────────────────────────────────────────────────────
+
+  xac.command.reload:
+    description: Reload XAC configuration
+    default: op
+
+  xac.command.status:
+    description: View a player's violation levels and ping
+    default: op
+
+  xac.command.punish:
+    description: Manually trigger a punishment for a player
+    default: op
+
+  xac.command.clearviolations:
+    description: Clear all violation levels for a player
+    default: op
+
+  xac.command.verbose:
+    description: Toggle verbose per-flag output for a specific player
+    default: op
+
+  xac.command.alerts:
+    description: Toggle receiving anti-cheat alerts in chat
+    default: op
+
+  xac.command.version:
+    description: Show the plugin version
+    default: true
+
+  # ── Alerts ───────────────────────────────────────────────────────────────
+
+  xac.alerts:
+    description: Receive alerts for all checks
+    default: op
+    children:
+      xac.alerts.movement: true
+      xac.alerts.combat: true
+      xac.alerts.misc: true
+
+  xac.alerts.movement:
+    description: Receive alerts for movement checks only
+    default: false
+
+  xac.alerts.combat:
+    description: Receive alerts for combat checks only
+    default: false
+
+  xac.alerts.misc:
+    description: Receive alerts for misc checks only
+    default: false
+
+  # ── Bypass ───────────────────────────────────────────────────────────────
+
+  xac.bypass:
+    description: Bypass all anti-cheat checks
+    default: false
+    children:
+      xac.bypass.movement: true
+      xac.bypass.combat: true
+      xac.bypass.misc: true
+
+  xac.bypass.movement:
+    description: Bypass all movement checks
+    default: false
+    children:
+      xac.bypass.speed: true
+      xac.bypass.fly: true
+      xac.bypass.jesus: true
+      xac.bypass.nofall: true
+      xac.bypass.timer: true
+      xac.bypass.spider: true
+      xac.bypass.glide: true
+      xac.bypass.phase: true
+
+  xac.bypass.combat:
+    description: Bypass all combat checks
+    default: false
+    children:
+      xac.bypass.killaura: true
+      xac.bypass.reach: true
+      xac.bypass.critical: true
+      xac.bypass.autoclicker: true
+      xac.bypass.velocity: true
+
+  xac.bypass.misc:
+    description: Bypass all miscellaneous checks
+    default: false
+    children:
+      xac.bypass.fastplace: true
+      xac.bypass.scaffold: true
+      xac.bypass.fasteat: true
+      xac.bypass.inventorymove: true
+
+  xac.bypass.speed:
+    description: Bypass SpeedCheck
+    default: false
+  xac.bypass.fly:
+    description: Bypass FlyCheck
+    default: false
+  xac.bypass.jesus:
+    description: Bypass JesusCheck
+    default: false
+  xac.bypass.nofall:
+    description: Bypass NoFallCheck
+    default: false
+  xac.bypass.timer:
+    description: Bypass TimerCheck
+    default: false
+  xac.bypass.spider:
+    description: Bypass SpiderCheck
+    default: false
+  xac.bypass.glide:
+    description: Bypass GlideCheck
+    default: false
+  xac.bypass.phase:
+    description: Bypass PhaseCheck
+    default: false
+  xac.bypass.killaura:
+    description: Bypass KillAuraCheck
+    default: false
+  xac.bypass.reach:
+    description: Bypass ReachCheck
+    default: false
+  xac.bypass.critical:
+    description: Bypass CriticalCheck
+    default: false
+  xac.bypass.autoclicker:
+    description: Bypass AutoClickerCheck
+    default: false
+  xac.bypass.velocity:
+    description: Bypass VelocityCheck (requires ProtocolLib)
+    default: false
+  xac.bypass.fastplace:
+    description: Bypass FastPlaceCheck
+    default: false
+  xac.bypass.scaffold:
+    description: Bypass ScaffoldCheck
+    default: false
+  xac.bypass.fasteat:
+    description: Bypass FastEatCheck
+    default: false
+  xac.bypass.inventorymove:
+    description: Bypass InventoryMoveCheck
+    default: false