AntiFreecam- Anti Anti ESP & Anti X-ray v1.3.4

The most advanced packet-level anti ESP, anti Freecam, and anti-X-Ray protection for 1.21 servers.

Stop cheaters from seeing underground bases, ores, chests, and players. AntiESPFreecam removes underground data from network packets before they reach the client — no cheat client can bypass server-side packet filtering.

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Donut AntiFreecam — What Does It Block?​

Anti ESP / Anti Wallhack
Surface players never receive block data below a configurable Y level. ESP mods and wallhack clients cannot render blocks the client doesn't have. Works against every known ESP client including Wurst, Meteor, Future, Impact, and custom hacked clients.

Anti Freecam
Players using Freecam to fly their camera underground see only air or a configurable mask block. No ores, no chests, no hidden bases — the data simply isn't there.

Anti X-Ray (Packet-Level)
Unlike ore obfuscation plugins that replace specific ores, AntiESPFreecam removes all block data below the Y threshold. X-Ray texture packs, X-Ray mods, and resource pack exploits are completely useless. This is true server-side anti-X-Ray protection.

Lazy Chunk Loading (Progressive Unmask)
When a player moves underground, chunks are not sent all at once. The plugin initially sends only a 3×3 area around the player and gradually loads additional chunks as the player moves within range. In elytra mode, the lookahead distance automatically doubles, ensuring no visual gaps even at speeds of 30–50 blocks per second. This approach eliminates network congestion spikes and distributes the load smoothly instead of sending ~625 chunks in a single burst.


Mod Detection
Automatically detects mods such as Freecam, Meteor Client, when a player joins, using a packet-level technique. No server-side blocks are placed, and the process is completely invisible to players. Detected players can be automatically kicked, and administrators with the antiesp.notify permission receive instant in-game alerts.



Discord Webhook Alerts
Each detection sends an asynchronous Discord notification with the player name, detected mod, and timestamp. The system has no performance impact and does not block the main server thread.

Anti Seed Cracker

Stops players from stealing your world seed. Seed-cracker mods like SeedcrackerX work by reading the hashed seed the server sends to every client (in the join and respawn packets) and using it as an instant verification oracle to confirm seed candidates they reverse-engineer from bedrock patterns and structures. AntiESPFreecam replaces that hash with a random value, removing the oracle and breaking the attack.

The hashed seed is only used client-side for cosmetic biome-border noise, so faking it has zero gameplay impact. Enabled by default (antiSeedCracker.hideSeed), works across all supported forks (Paper / Purpur / Folia / Leaf, MC 1.21.x). For full coverage, also enable Paper's feature-seeds.generate-random-seeds-for-all so structure and ore placement can't be used to brute-force the seed either.


Light Data Masking
When chunk sections are masked (blocks replaced with maskBlock), the plugin also resets all lighting data (sky light and block light) for those sections. Without this protection, modified clients using ESP or X-ray hacks can analyze light patterns within a masked chunk to infer cave shapes, lava locations, or torch positions — even if the actual blocks have been replaced.

Anti Entity ESP
Mobs, dropped items, minecarts, armor stands, and all other entities below the Y threshold are hidden from surface players at the packet level. Entity radar and entity ESP cheats see nothing.

Anti Player ESP / Anti Player Radar
Underground players are completely invisible to surface players — hidden at the server level before any data reaches the client. Player tracers, player ESP, and radar mods cannot detect hidden underground players.

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How Does Server-Side DONUT Anti ESP Work?​

AntiESPFreecam operates at the network packet level using ProtocolLib. It intercepts MAP_CHUNK packets before they reach the client and replaces chunk sections below the Y threshold with empty data. This approach is fundamentally different from ore obfuscation:

• True server-side protection — underground data never reaches the client. No cheat client can extract data that was never sent.
• Zero TPS impact — masking happens inline in the ProtocolLib packet pipeline with zero additional MSPT cost during normal gameplay. No extra packets, no scheduled tasks, no performance overhead.
• Frame-perfect masking — players never see real underground blocks, not even for a single frame. Protection is active before the chunk is rendered client-side.
• Smart Y-threshold transitions — when a player goes underground, they automatically receive real data. When they return to the surface, masking activates instantly with optimized NMS chunk resend.
• Lightweight packet processing — uses shallow clone optimization for minimal memory allocation and garbage collection pressure.

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Feature List

• Configurable Y-level masking — set the exact Y level below which all block data is stripped
• Packet-level anti-X-Ray — removes entire chunk sections, not just ores; defeats X-Ray mods, texture packs, and resource pack exploits
• Light data masking — resets sky light and block light in masked sections so ESP clients can't infer caves from light patterns
• Entity packet filtering — hides mobs, items, minecarts, armor stands, and vehicles below the threshold
• Underground player hiding — server-native player hiding, undetectable by player ESP, tracers, or radar mods
• Lazy chunk loading — progressive unmask with elytra-aware dual-mode; no network spike on underground transition
• Mod detection — automatically detects Freecam, Meteor Client, and Wurst on join; optional auto-kick
• Discord webhook alerts — async rich embeds on detection with player name, mod name, and timestamp
• Admin notifications — in-game alerts to staff with antiesp.notify permission
• Admin bypass system — /antiesp bypass [player] for staff, builders, and moderators
• Full config.yml customization — Y threshold, scan radius, mask block, chunks per tick, unmask distances, and more
• Live config reload — /antiesp reload applies changes without server restart
• Optimized performance — lazy timer architecture, striped async executor pool, processor runs only when needed
• Paper 1.21.x compatible — works with Paper, Purpur, Folia, Canvas, and other forks

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Requirements & Compatibility​

Commands & Permissions

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Ongoing Support & Updates​

This plugin is actively developed and maintained. We provide continuous support — if you encounter any issues, have questions, or need help with configuration, reach out to us anytime. We regularly release updates to ensure full compatibility with the latest ProtocolLib versions.