SentinelCore - AntyCheat

1.2.3 [2] - Flight Detection Overhaul

Added

- Ground Spoof detection - new dedicated check that verifies the client's onGround flag against the server's own physical collision test, catching players who fake ground contact (e.g. to suppress fall damage or slip past hover detection). - MotionY physics-curve check - Flight now simulates vanilla's actual vertical physics tick-by-tick and flags clients that deviate from it, catching subtler Fly hacks that fake a "legal-looking" trajectory instead of holding altitude outright. - Vertical grace periods - knockback, explosions, Slime Block/Bed bounces, Wind Charge, and vehicle exits now grant a temporary, magnitude-scaled window where vertical checks relax, instead of a blanket "ignore everything" exemption. - Position correction - once Flight/Ground Spoof evidence crosses the configured VL threshold, the player is reverted to their last confirmed safe ground location rather than just having the packet cancelled. - New config sections: checks.flight.* and checks.ground-spoof.*, fully validated and hot-reloadable.

Changed

- Flight's hover detection now requires only 5 consecutive near-zero-delta ticks (down from 12) while airborne, tightening detection without needing a long airtime cap. - Rewrote FlightCheck internals to reduce false positives around slime bounces, bed bouncing, and vehicle dismounts.

Fixed

- Slime Block, Bed, and vehicle-exit interactions no longer risk being misread as hover/motion anomalies. Full technical detail available on request - this release focused on the Flight/Hover/GroundSpoof detection module specifically.

SentinelCore — Anti-Knockback (Velocity) Detection

Added

New Knockback check: detects a client reducing or fully canceling the recoil applied after a melee hit ("NoKnockback"/"Anti-KB"), while filtering out lag, ping drops, and legitimate block/liquid/climbing interference. Uses a packet-confirmed synchronization window (via ProtocolLib, if installed) so only movement the client sent after actually receiving the knockback packet is measured - eliminates false positives from in-flight packet timing. Automatically exempts: wall/ceiling collision in the knockback's path, water/lava/bubble columns, ladders/vines/scaffolding, vehicles, stacked/conflicting damage sources, high ping, and ping jitter. Only evaluates velocity changes correlated with a recent melee hit - explosions, ender pearls, elytra boosts, and other plugin-driven velocity are ignored. Scores onto the existing decaying violation buffer, with its own configurable thresholds - no false-flag on a single deflection; sustained/full negation is required before any action. Optional automatic correction: re-applies the missing recoil directly (no teleport/rubberband) instead of only reporting.

Changed

None to existing checks' behavior - this is purely additive.

Requirements

Full precision requires ProtocolLib (already an optional soft-dependency for other features). Without it, the check still runs using a fixed-delay fallback, with reduced precision under network jitter.

Added (config.yml - checks.knockback)

enabled, sync-window-ticks, sync-timeout-ms, min-expected-horizontal, tolerance, full-negation-evidence, combat-correlation-window-ms, max-safe-ping-ms, max-ping-jitter-ms, correct-velocity, cancel-confidence, cancel-violations, alert-confidence, alert-violations, min-consecutive-flags, consecutive-window-ms All defaults are tuned conservatively (20% recoil tolerance, requires 2 consecutive flags within 1.5s) to minimize false positives out of the box. Known limitation for release notes: the ProtocolLib packet-handling code in KnockbackSyncService has not been compiled/tested against a live ProtocolLib build in this environment - verify it against your pinned ProtocolLib version before shipping a release build.

# Added Loaders Support:

- Bukkit, Purpur, Spigot

# Added Version Support:

- 1.17.x, 1.18.x, 1.19.x, 1.21.x _- Problems with 1.20.x_

SentinelCore - AntyCheat 1.1.1

Fixed

- Calibration sessions no longer finalize prematurely. CalibrationSession.isComplete() previously returned true after as few as ~60 movement samples (a few seconds of play), even though calibration was advertised to staff and players as an hour-long process. It now also requires a full hour of wall-clock collection before a session can complete. - False positives from teleports and respawns. Warps, portals, /spawn, and death respawns produce an instantaneous position delta with no relation to normal physics. The very next movement tick was being judged against that jump by the speed and vertical-motion checks, producing false "prediction error" flags. Teleports and respawns now grant the existing movement exemption window before the next check runs.

Changed

- Passive mode (alert-only) is now the default enforcement posture. Added general.passive-mode (default true). While enabled, no check cancels a movement/attack event or rubberbands the player back — evidence is still gathered, scored, and reported to staff exactly as before, just without any client-visible correction. Set to false to restore active enforcement (event cancellation + rubberband). - FlightCheck is now registered (it existed in the codebase but was never wired into SentinelCorePlugin).

Added

- `FallCheck` — passive, alert-only monitor for NoFall-style exploits. Tracks accumulated airborne descent per player and compares it against actual damage taken on landing, accounting for Feather Falling, Slow Falling, and Levitation. Always alert-only regardless of passive-mode, since by the time fall damage is calculated there is no movement left to roll back. - `StepCheck`, `SpiderCheck`, `JesusCheck` — new movement checks for step-height abuse, wall-climbing, and liquid-walking, built on a new SurfaceMovementSample that carries horizontal-collision, fluid, and climbable-block state without requiring NMS. - New config sections: checks.fall, checks.step, checks.spider, checks.jesus, checks.flight, and general.passive-mode.

Files touched

- Added: check/impl/FallImpactSample.java, check/impl/FallCheck.java, check/impl/SurfaceMovementSample.java, check/impl/StepCheck.java, check/impl/SpiderCheck.java, check/impl/JesusCheck.java - Edited: calibration/CalibrationSession.java, config/ConfigManager.java, listener/DetectionListener.java, listener/SessionListener.java, profile/PlayerProfile.java, SentinelCorePlugin.java, resources/config.yml

SentinelCore v1.1.0 - Changelog

What's New

Introduced AI-assisted calibration - SentinelCore now uses adaptive, confidence-based analysis to learn each player's normal movement and behavior patterns, improving detection accuracy and reducing false positives compared to static thresholds.

Improvements & Fixes

Improved stability of the calibration system, fixing an issue where calibration data could be recorded with an incorrect timestamp. Improved compatibility with the latest Paper server versions, ensuring isolated calibration worlds are created reliably using currently supported server APIs. Fixed a rare startup issue that could cause calibration tasks (telemetry updates and session tracking) to fail with an internal access error after certain build/update processes. A clean plugin rebuild/reinstall resolves this.

Notes

No changes to existing configuration, permissions, or commands - this is a stability and accuracy update. If you're running an older Paper build, we recommend updating to the latest stable release for the best compatibility. --- _Thanks for using SentinelCore! As always, feel free to report any issues._

Working on:

* KillAura * CrystalAura * AnchorAura * BedAura * BowAimbot * BowSpam * Criticals * Hitboxes (powiększone hitboxy) * AutoWeapon * AutoTotem * AutoArmor * AutoEXP * AutoTrap * AutoWeb * AutoCity * Burrow * Surround * SelfTrap * SelfWeb * SelfAnvil * AntiBed * AntiAnchor * AntiAnvil * ArrowDodge * Offhand * Quiver * AutoLog * Flight * ElytraFly * ElytraBoost * Speed * LongJump * HighJump * AirJump * Step * ReverseStep * NoFall * NoSlow * Velocity * Jesus * Spider * Scaffold * SafeWalk * Sprint * Sneak * Blink * ClickTP * TridentBoost * FastClimb * AntiVoid * Parkour * AutoWalk * AutoJump * EntityControl * Reach * AutoClicker * SpeedMine * PacketMine * BreakDelay * InstantRebreak * FastUse * GhostHand * LiquidInteract * NoMiningTrace * NoInteract * NoRotate * Multitask * AutoTool * AutoGap * AutoEat * AutoFish * AutoMend * AutoRespawn * AutoReplenish * EXPThrower * AirPlace * AntiHunger * Nuker * PacketMine * Timer * VeinMiner * Excavator * HighwayBuilder * InfinityMiner * BuildHeight * NoGhostBlocks * LiquidFiller * SpawnProofer * Spam * PacketCanceller * ServerSpoof * InventoryTweaks * AutoReconnect * Xray * WallHack * ESP * StorageESP * Chams * Tracers * Nametags * Freecam * Fullbright * Zoom * FreeLook * HoleESP * ItemHighlight * NoRender * WeatherChanger * TimeChanger * KillAura * Reach * Criticals * AutoClicker * Hitboxes * BowAimbot * Velocity * Flight * Speed * NoSlow * NoFall * Scaffold * Step * Blink * Jesus * Spider * LongJump * HighJump * SpeedMine * PacketMine * Nuker * Timer * FastUse * GhostHand * AimAssist * SilentAim * TriggerBot * FakeLag * LagSwitch * Timer Balance * Rotation Spoof * BadPackets * InvalidSprint * InvalidSneak * FastBreak * FastPlace * InventoryMove * InventoryCleaner * ChestStealer * FastBow * FastProjectile * OmniSprint * OmniDirection * AntiKnockback * TimerBoost * Phase * BoatFly * ElytraSpeed * PingSpoof * PacketFly * NoWeb * FastLadder * FastEat * AutoPotion * AutoPearl * FastThrow * Blink Combat * BackTrack * KeepSprint * WTap Macro * STap Macro * AimBot * AntiBot * AntiLegitMiss * AntiPhase * Attribute Swap * Aura * AutoAnchor * AutoAnvil * AutoBasePlace * AutoBed * AutoBuff * AutoClicker * AutoCrystal * AutoCrystalBase * AutoDripstone * AutoGapple * AutoMine * AutoNetherite Scrap * AutoSweet Berries * AutoTotem * AutoTrap * AutoWeb * Blocker * Bow Minecart * Bow Spam * Breaker * Burrow * Crystal Bind * Criticals * FireSpam * HitBoxes * HoleESP * HoleFill * Legit Totem * LegitHelper * Mace Killer * Mainhand Totem * MoreKnockback * Offhand * PistonAura * PistonPush * Quiver * Reach * Self Trap * Surround * TNT Aura * TargetHelper * TargetStrafe * TriggerBot * Anti Knock Back * Anti Void * Anti Web * Avoid * Blink * Boat Fly * Elytra Freeze * Elytra Plus * Elytra Recast * ElytraReplace * ElytraSpeed * ElytraSwap * Elytra Target * EntityControl * EntitySpeed * Flight * FreeCam * GuiMove * High Jump * HoleAnchor * HoleSnap * Infinite Elytra * Jesus * Legit Strafe * Levitation Control * LevitCtrl * Long Jump * Mace Elytra Target * Move Fix * No Fall * No Push * No Slow * No Water Collision * Parkour * Phase * Reverse Step * SafeWalk * Scaffold * Speed * Spider * Sprint * Step * Strafe * TickShift * Timer * TridentBoost * Velocity * WaterSpeed * Wind Hop * Absorption * Aspect * BlockESP * BlockHighlight * BreadCrumbs * Break ESP * Buff Effect * Charms * Crystal Chams * Damage Particles * Damage Tint * Dismemberment * ESP * FOV * Free Look * Full Bright * Fullbright * Hand Chams * Hit FX * HitBubbles * HitParticles * Hole ESP * Item ESP * JumpCircle * KillEffect * Logout Spots * NameTags * No Bob * No Camera Clip * No CameraClip * No Render * Particles * Pearl Phase ESP * Player ESP * Pop Chams * Projectile Predict * RenderMode * Search * Shaders * SoundESP * Storage ESP * TimeChanger * TotemAnimation * Totem Animation * Tracers * Trails * Trajectories * TunnelESP * ViewModel * Void ESP * World Renderer * X Ray * Action Recorder * Air Place * Anti Aim * Anti Attack * Anti Hunger * Auto Armor * Auto Auth * Auto Bone Meal * Auto Command * Auto Fish * Auto Land * Auto Leave * Auto Mend * Auto Respawn * Auto Shear * Auto Sign * Auto Tool * Auto TPA Accept * Auto Wither * Box Shrinker * Chest Stealer * Chorus Delay * ClickGUI * ClientSettings * CustomMainMenu * CustomPanorama * CustomLoadingScreen * Debug * DiscordRPC * EC Exploit * EbatteStrate * Exploitcore Capes * ExtraTab * FakeLGBT A * FakePlayer * FastLatency * FastTrident * FakePlayer * ForceOP * FutureCompatibility * Ghost * HideFriends * HudEditor * Inventory Cleaner * Inventory Manager * ItemScroller * KillCommand * LagNotifier * Language * Media * MessageAppend * MiddleClick * MouseElytraFix * MultiTask * NameProtect * NoCommentExploit * No Delay * No Entity Trace * No Interact * No Jump Delay * No Packet Exception * No Server Rotate * No Server Slot * PacketCanceler * PearlChaser * PearlBlockThrow * PearlBit * Perfect Delay * PingSpoof * PlayerOnlineList * Portal God Mode * PortalInventory * ReadyNotification * Regen * Rotations * ScaleFactorFix * ServerHelper * SoundFX * Spammer * Speed Mine * StashLogger * TapMouse * Telemetry * TpsSync * ToolSaver * Tooltips * TotemPopCounter * Trace Through * Tracker * UnHook * ViewLock * VisualRange * VoidESP * WayPoints * Windows * World Renderer * XCarry * XRay * Zoom * Anti Resource Pack * Assistant * Auto Eat * Auto Ez * Auto Leave * Auto Potion Brew * Auto Soup * Auto Trader * Extra Tab * Fast Latency * Message Append * Name Protect * Notifier * Ping Spoof * RPC * Source Filler * Spammer * Tape Mouse * Team Communication * Test * Translator * UI - Priority

SentinelCore

SentinelCore is an adaptive, confidence-based anti-cheat foundation built specifically for Paper servers. It prioritizes reliable detection and low false-positive risks over a high volume of flags by using historical evidence and adaptive behavioral baselines. Designed with performance and stability in mind, SentinelCore operates entirely through the Paper API, meaning it does not require ProtocolLib or NMS injections to function.

Core Features

Advanced Movement Validation:* Uses a state-aware movement model for adaptive movement-envelope validation. Combat & Interaction Analysis:* Evaluates click-patterns using CPS and rolling timing deviation, alongside reach validation that actively compensates for latency and physical obstructions[cite: 2]. Intelligent Exemptions:* Automatically exempts players from checks during uncertain conditions like low server TPS, teleports, respawns, desynchronization gaps, and vehicle usage to protect legitimate players[cite: 2]. Live Profile Dashboard:* Staff can access a read-only GUI dashboard (/ac [player]) to view live statistics, movement profiles, reaction scores, and reach deviations[cite: 2]. Dynamic Performance Scaling:* Automatically adjusts its execution budget and check frequency based on live server TPS and player count to maintain strict server thread health[cite: 2].

Important Notice

SentinelCore currently operates as an event-driven detection foundation[cite: 2]. When evidence thresholds are reached, it emits detailed staff alerts[cite: 2]. It does not automatically kick, ban, or punish players[cite: 2].

Localization

The plugin supports multiple languages out of the box, including English, French, Arabic, German, Turkish, Portuguese, Italian, Japanese, and Simplified Chinese[cite: 2].

Commands & Permissions

* /ac [player] - Opens the profile GUI[cite: 2]. * /ac alerts - Toggles staff alerts[cite: 2]. * /ac bypass <player> - Exempts a player from checks[cite: 2]. Permissions:* sentinelcore.admin (Full access), sentinelcore.alerts (Receive alerts), sentinelcore.bypass (Exempt from checks)[cite: 2].