MeshAC 1.0.0

MeshAC is a server-side anticheat for Fabric 26.2. It has movement simulation, packet analysis, and (hopefully) accurate heuristics to detect hacked clients like meteor.

This mod doesn't scan clients, collect files, inspect mods, or bundle other software.

Why MeshAC

Compatibility

Detection Suite

Movement (12 checks)

Combat (13 checks)

Player & Exploit (18 checks)

Anti-Cheat Architecture

Buffer System

Every check uses a per player, per check buffer that gains evidence before producing a violation. This prevents singletick errors like lag spikes, chunk borders, and vehicle dismounts from ever punishing legit players.

Check detects anomaly → buffer += weight
                       → if buffer > threshold → produce VL
                       → else → no action
Check sees normal behaviour → buffer *= decay (0.8-0.9)

Lag Compensation

• TPS floor: All checks pause below a configurable TPS (default 18.0)
• Ping aware tolerances: Reach, timer, and velocity checks scale with the player's ping
• Packet stall detection: Timer check ignores deficits during 5s+ stalls
• Velocity window: Knockback tracking runs for 10 ticks to catch partial anti KB

Detection Layers

MeshAC combines multiple heuristics so that a cheater has to bypass all of them at the same time:

1. Hard limit — biologically impossible values
2. Soft limit — sustained values beyond human capability
3. Statistical analysis — distribution shape, standard deviation, skewness
4. Behavioural correlation — click-to-movement, rotation-to-target, placement cadence
5. Server simulation — tick-accurate prediction with AABB collision

Escalating Punishment

VL accumulates → notify staff → setback → kick → tempban → permanent ban

Each stage fires once and is configurable per check.

Install

1. Install Fabric Loader and Fabric API for Minecraft 26.2.
2. Copy meshac-1.0.0.jar to the server's mods/ directory.
3. Start the server once. MeshAC writes config/meshac.yml.
4. Keep defaults while observing, then tune individual checks.

Configuration

config/meshac.yml:

checks:
  enabled: true
  entries:
    fly:
      enabled: true
      threshold: 0.05
      actions: ["notify", "setback"]
      max_vl: 6
      decay_ticks: 600
      check_interval: 1
      max_vl_per_tick: 5.0

performance:
  min_tps: 18.0
  max_players_per_tick: 50
  mode: balanced  # aggressive | balanced | relaxed

alerts:
  enabled: true
  min_vl: 2

geyser:
  exempt: true

Per-check options

Performance modes

Commands

All commands are under /meshac and require operator permissions: