Nimbus AntiCheat

Nimbus AntiCheat is a free Minecraft server plugin that uses movement prediction and packet inspection to detect cheats. Its listing describes 43 individually adjustable checks across movement, combat, world, packet, and inventory categories. Checks account for factors such as latency, server lag, movement buffs, teleports, knockback, flight toggles, and join grace. Detection and staff alerts are enabled by default, while punishments are off until an operator configures them. Staff tools include player reports, an inspection GUI, in-game check controls, violation logs, and commands for testing alerts and punishments. Operators can configure enforcement actions such as kicks, bans, freezes, setbacks, and illegal-action cancellation. PacketEvents is required; PlaceholderAPI, Discord webhooks, Citizens, LiteBans, and a permissions plugin are optional integrations. Nimbus requires Java 21 and targets Paper 1.21.x; it was built and tested against Paper 1.21.8, while other 1.21.x builds are untested. It supports Java-edition players, not Bedrock or Geyser players, and older versions such as 1.8 and 1.20 are unsupported.

Nimbus provides configurable detection and staff tools, with punishments left to the operator to set up. Check its Java, PacketEvents, and Minecraft-version requirements before installing.

Nimbus suits server operators who can review alerts, tune checks, test enforcement, and decide when to enable punishments. It is intended for Java-edition players on Paper or a compatible fork.

Nimbus AntiCheat is a free, self-hosted Minecraft server plugin that combines movement prediction with packet inspection. It suits operators running current Paper-based Java servers who are prepared to tune detection and supervise staff workflows. Its broad, adjustable checks and cautious enforcement defaults make it a strong fit for managed communities, but version and platform restrictions rule it out for mixed Java-Bedrock networks.

Overview

Nimbus covers 43 checks across movement, combat, world, packet, and inventory categories, with each check independently switchable and tunable. Detection and staff alerts are active immediately, while punishments remain off until an operator configures them. That division supports a measured rollout: staff can observe violations, adjust thresholds, and test commands before kicks or bans affect players. It also means Nimbus is not a set-and-forget anti-cheat; servers need people who can interpret alerts and calibrate responses.

The plugin is free and runs on your own server. Its intended environment is Paper 1.21.x, with Paper 1.21.8 as the build and test target. Java 21 and the standalone PacketEvents plugin are required, and only Java-edition players are supported. Bedrock and Geyser users, along with servers on older branches such as 1.8 or 1.20, are outside its compatibility range.

For broader comparisons, see our Minecraft Anti-Cheat Plugins list.

Key features

Wide, adjustable detection

Movement coverage includes speed, prediction, bunny hopping, flight, vertical motion, high jumps, stepping, fall-damage avoidance, slowed movement, web and water behavior, phasing, climbing, inventory movement, and velocity. Combat checks address kill aura, NPC-targeted aura, reach, auto-clicking, critical hits, attacks through walls, invalid attacks, and client-brand signals. World checks target scaffolding, tower building, block breaking, and rapid placement. This range gives specialists room to focus on the abuses that matter on their server instead of accepting one fixed policy.

Context and enforcement controls

Latency, server lag, movement effects, teleports, knockback, flight toggles, and join grace are considered when checks evaluate behavior. Those conditions can reduce avoidable flags, although operators still need to review alerts before automating severe penalties. Available actions include alerting, violation logs, configurable commands, kicks, temporary or permanent bans, freezes, setbacks, illegal-action cancellation, and Discord notifications.

Staff workflow and integrations

Player reports, a staff inspection GUI, in-game check controls, staff notes, audit logs, group inheritance, temporary permissions, replay analysis, and report workflows make Nimbus more useful for teams than a detection-only plugin. Alert and punishment test commands help verify a policy before deployment. PacketEvents is mandatory; PlaceholderAPI, Discord webhooks, Citizens, LiteBans, and LuckPerms or another permissions plugin are optional integration points. YAML is the storage backend. Proxy support is included, but there is no staff web panel.

Pricing

Nimbus is free for self-hosted use. The Free plan costs nothing and includes 43 checks, Paper 1.21.8 support, per-check punishments, player reports, staff inspection tools, and Discord webhook notifications. The Nimbus AntiCheat plan also costs nothing and specifies Paper 1.21.8 compatibility (compatible forks may work), Java 21, required PacketEvents, and Java-edition players only.

There is no paid tier to unlock more checks or staff functions. The trade-off is operational rather than financial: you supply the supported server stack, configuration work, and ongoing review of alerts.

Platforms

Nimbus is a server plugin for Paper or a compatible fork, with Spigot identified among supported platforms. It targets Minecraft 1.21; other 1.21.x builds may work but are untested. Java 21 and PacketEvents are prerequisites. Java-edition players are supported, while Bedrock and Geyser players are not. WorldEdit schematic files are supported as a file format, and deployment is through a server-plugin placement workflow.

Who it's for

Choose Nimbus if you operate a Paper 1.21 server, have Java 21 available, and can assign staff to inspect alerts, tune checks, test enforcement, and enable punishments only after calibration. It is particularly suitable for communities wanting granular control and an in-game moderation process without a license fee.

Look elsewhere if your network must admit Bedrock or Geyser players, remain on 1.20 or older versions, or rely on unattended automatic punishment. Nimbus's defaults are safe, but its effective use depends on operator involvement.

Pros and cons

Pros

• 43 individually tunable checks: Operators can target specific movement, combat, world, packet, and inventory behaviors.
• Careful rollout: Alerts and logging work before punishments, allowing calibration and testing.
• Strong staff toolkit: Reports, inspection, notes, audit logs, replay analysis, and test commands support investigations.
• No license cost: Both published plans are free for self-hosted servers.

Cons

• Narrow compatibility: Java 21, PacketEvents, Paper 1.21.x, and Java-only players exclude many networks.
• No web panel: Staff work is centered on the server and its in-game tools.

Alternatives

LibertyBans is a free option for operators who need a broader API or self-hosted deployment and Java 17 compatibility.

ModGUI is another free self-hosted choice, licensed under MIT and aimed at Paper 1.21.11 or newer.

Staff+ fits teams seeking a free MIT-licensed moderation plugin spanning Paper, Purpur, Folia, and Velocity.

ExtraBan is a free self-hosted alternative for Paper or forks on 26.2+ with Java 25+.

Player Report is a free server plugin focused on reporting on native/tested Minecraft 1.21.

ReportsGUI is a free reporting plugin for native major version 1.17, capped at 54 unhandled reports.

BanManager is a free, open-source option with API, Linux, self-hosted, and web availability.

AdvancedSensitiveWords is a free self-hosted alternative.

For related moderation, permissions, and schematic tooling, browse our Minecraft Moderation Plugins, Minecraft Permissions Plugins, and Minecraft Schematic Tools lists.

Verdict

Its main reason to choose it is the combination of broad detection and staged enforcement. Its main reason to look elsewhere is strict Java, Minecraft-version, and player-platform compatibility, especially for networks that include Bedrock users or older servers.