OmniGuard#

All-in-one security for Spigot, Paper, Purpur and Folia, Minecraft 1.17.1 → 26.2. One jar plus the free PacketEvents library plugin, Java 17+.

Layer	What it stops
Packet firewall	Crash exploits, book bans, NaN/out-of-world movement, packet and byte floods, invalid slots/clicks, crash commands, channel abuse. All handled on the network thread, before the server works on them
Anti-dupe	Item Provenance Ledger: valuable items carry an invisible identity, so a dupe is caught however it was made. Includes chain of custody, gain monitor, known dupe patches and illegal-item repair
World shield	Redstone clocks, piston and hopper floods, entity caps, explosion floods, chunk and book bans, chunk-generation floods. Limits tighten automatically when TPS drops
Connection shield	Connection and login floods, automatic attack mode, ban-evasion links, rejoin cycling, lockdown
Hardening	Untrusted OPs, plugin fingerprinting, `/og doctor` configuration audit

Why admins pick it#

Proof, not promises. Every release is replayed against a real Paper server: 37/37 exploit scenarios handled with 0 false positives on legitimate players. See Test results.
Low false positives by design. Violation levels decay over time, monitor-mode lets you observe before blocking, and an internal error never punishes a player.
Learns your server. Auto-Tune builds packet limits from your own players' real traffic.
Evidence. Every punishment saves the connection's last 64 packets to a file.
Built for developers. A typed service API with events, exemptions and ledger access.

Put PacketEvents and OmniGuard-x.y.z.jar in plugins/ and restart (do not use /reload).
Run /og doctor and fix anything marked CRIT.
Add your staff to checks.privilege-guard.trusted-operators.
Optional: add a Discord webhook. See Alerts.