ServerShield

Crashers don't log in with a warning. They send a book with 900 pages of box-drawing glyphs, a sign that kills the render thread, or a few thousand packets per second. Your server is gone before anyone can type /kick.

ServerShield sits inside the packet pipeline and drops that traffic before the server ever sees it.

🛡 What it blocks

• Book bombs: oversized books, glyph bombs (book ban style)
• Sign crashes: hostile unicode on signs
• Tab complete abuse: NoCom style long completions and completion spam
• Payload abuse: oversized or blocked plugin channels
• Packet floods: weighted per-packet rate limits (position, ping, interact spam)
• Chat and command bursts
• NBT bombs: creative items stuffed with bloated NBT
• Malformed packets that fail protocol parsing

⚖ How it reacts

Every violation adds points to a rolling per-player score that decays over time. Cross a threshold and it escalates on its own:

1. staff with servershield.alerts get an in-game alert
2. the player gets kicked
3. repeat offenders get a tempban

You set the thresholds, the decay and the ban duration. Three built-in modes (default, strict, paranoid) if you don't want to tune numbers by hand. Kicks and bans can ping a Discord webhook.

🎛 Commands

/shield              live status panel
/shield checks       list checks and their state
/shield toggle <check>
/shield reload
/shield test         trip a test violation on yourself

Permissions: servershield.use · servershield.admin · servershield.alerts · servershield.bypass

🔧 Under the hood

• Paper 1.21+ and Folia, no other plugins required (PacketEvents is bundled and relocated)
• Checks run off the main thread, no tick cost on a clean server
• Every check has its own limits, flood weights are set per packet type
• Whitelist and a bypass permission for trusted players

🤝 Pairs with ServerAudit

ServerAudit finds the holes in your config. ServerShield closes the runtime door. Same author, same idea: security tools that don't need a setup wizard.

Free, forever

No paid version, no feature gates, no nag screens. If it caught something your old setup missed, a review helps other admins find it.