Negativity (modernized)

Minecraft anticheat rebuilt for modern Paper (and Purpur-compatible forks), with companions for BungeeCord and Velocity.

This repository contains:

1. Modern modules (recommended) — Java 21, Gradle, buffer-based detections
2. Legacy V1 sources under /src — original free plugin (unmaintained upstream)

Upstream project: Elikill58/Negativity

Supported targets (modern build)

Platform	Status
Paper 1.20.4+ / 1.21.x	Primary
Purpur / Paper forks	Compatible via Paper API
BungeeCord companion	Minimal (message validation)
Velocity companion	Minimal (message validation)
Java	21 (toolchain)

Legacy 1.8–1.16 is not the focus of the modern modules. Keeping full 1.8 support in the same code path would harm modern detections.

Requirements

• JDK 21
• Paper (or fork) for the Spigot module
• Optional: ProtocolLib (future packet layer)

Build

# Windows
gradlew.bat build

# Linux / macOS
./gradlew build

Artifacts:

• negativity-spigot/build/libs/Negativity-<version>.jar — put in plugins/
• negativity-bungeecord/build/libs/Negativity-Bungee-<version>.jar
• negativity-velocity/build/libs/Negativity-Velocity-<version>.jar

./gradlew :negativity-tests:test

Install

1. Build or download the Spigot/Paper JAR
2. Drop it into the server plugins/ folder
3. Start once to generate config.yml, checks.yml, messages.yml, punishments.yml
4. Adjust thresholds; keep punishments.enabled: false until tuned

On proxies, install the matching companion and the plugin on each backend where players should be checked.

Commands

Command	Permission	Description
/negativity	negativity.negativity	Help / root
/negativity alerts	negativity.alert	Toggle personal alerts
/negativity check <player>	negativity.check	Live VL / latency
/negativity violations <player>	negativity.negativity	Recent flags
/negativity debug <player> <check>	negativity.admin	Why analysis is skipped
/negativity reload	negativity.reload	Safe config reload
/negativity info	—	Version / TPS
/negativity exempt <player> [seconds]	negativity.exempt	Manual exemption
/negativity logs <player>	negativity.negativity	Alias of violations

Aliases: /n, /neg

Configuration

File	Role
config.yml	Global, latency, TPS, alerts, storage, proxy
checks.yml	Per-check enable + VL thresholds + setback
messages.yml	User-facing messages (pt_BR defaults)
punishments.yml	Progressive command punishments

Checks use buffers, decay, and separate alert / setback / punish thresholds. High ping does not hard-disable all detections; it increases movement tolerance.

Public API (for plugins)

NegativityAPI api = NegativityAPI.get();
api.exemptions().exempt(playerId, ExemptReason.PLUGIN, 2000);
api.violations().getVl(playerId, "speed");
api.checks().setEnabled("fly", false);

Architecture (modern)

negativity-api          Public interfaces / records
negativity-common       Managers, buffers, version, config defaults
negativity-spigot       Paper plugin + checks + commands
negativity-proxy-common Shared proxy channel/validation
negativity-bungeecord   Bungee companion
negativity-velocity     Velocity companion
negativity-tests        Unit tests

Current checks (modern module)

Check	Subchecks	Notes
Speed	A/B	Ground/air + potions + latency
Fly	A/B	Hover / ascend air ticks
Timer	A	Movement packets/s window
NoFall	A/B	Ground spoof while falling
Jesus	A	Walking on liquids
Spider	A	Wall climb
Step	A	Impossible step height
Phase	A	Inside solid blocks
NoSlow / NoWeb / FastLadder	A	Slow contexts
AirJump	A	Double jump-like
ElytraFly	A/B	Glide speed / hover
InventoryMove	A	Move with GUI open
Reach	A	AABB edge distance
KillAura	A/B	Angle + multi-switch
AutoClick	A	CPS
Criticals / Velocity / FastBow	A	Combat helpers
Scaffold / Nuker / FastPlace	A/B	World interaction
Regen	A	Regen interval
BadPackets	A–F	Spam / impossible rates

Known limitations

• ProtocolLib recommended for accurate Timer/BadPackets
• MySQL connection pool not implemented yet (SQLite/file ready; architecture allows later)
• Folia not supported
• Thresholds need live tuning on production traffic
• Legacy V1 sources under /src are not the runtime for modern JAR

License / credits

Original Negativity by Elikill58 and contributors.
Modernization work is based on that codebase.