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3 min readSentra Team

Anti-WallHack Lite — a Free Fog of War for Your FiveM Server

We extracted the Fog of War from Sentra Anticheat and released it for free. sentra-fow hides players behind walls from every client, so wallhack cheats see nothing. Here is how it works, what it can't do, and when to use the full version.

  • anti-wallhack
  • fog-of-war
  • free
  • fivem
  • anticheat
  • open-source

Wallhacks are one of the most common cheats on FiveM, and one of the most frustrating: the cheater sees every player through every wall, and you can't see anything wrong.

Today we are releasing a piece of Sentra for free: Anti-WallHack Lite, published as the resource sentra-fow. It is the Fog of War system from Sentra Anticheat, extracted so any FiveM server can use it with no API key and no account.

Watch the video above for a demo, then read on for how it works and where its limits are.

What is Fog of War?

Fog of War stops the problem at the source. If a player is physically blocked from view by a wall, their ped is concealed from your client. A wallhack can only draw what the game has loaded, so there is nothing to draw.

How it works

Every client runs its own line-of-sight checks against nearby players:

  1. From the camera position, it casts a ray to the target's chest and four side markers.
  2. If every ray hits a solid wall, the player is concealed with NetworkConcealEntity.
  3. If any ray gets through, the player is revealed again immediately.

A few details make it feel natural in a fight:

  • Velocity-aware markers. A sprinting player gets wider side markers, so they are not hidden too early while running around a corner.
  • Glass-aware. Windows, car glass and chain-link fences never block visibility.
  • Reciprocal visibility. If player A can see player B, the server tells B to always render A. Neither side gets an unfair blind spot.
  • Fast reveal. Hidden players are rechecked every 16–32 ms when close, so someone stepping into view appears at once.

Install in two steps

  1. Drop the sentra-fow folder (fxmanifest.lua, client.lua, server.lua) into your resources folder.
  2. Add this to your server.cfg:
ensure sentra-fow

There is no framework requirement, no dependency and no config file. If you want to tune it, the values sit at the top of client.lua: marker radius, recheck intervals, the maximum distance for side raycasts and more.

Performance

All the raycasting runs on each client, so it costs no server CPU. The server only relays a tiny visibility signal. On the client, it can cast up to 5 rays per nearby player, so performance can drop in very large, dense groups of players.

Know the limits

This is a free release, and we want to be clear about what it is not.

  • The decision is made on the client. A modified client can ignore NetworkConcealEntity and still render hidden players. That is a known limitation of any client-only Fog of War.
  • Interiors are excluded. Some interior glass and transparent surfaces can't be told apart from solid walls by a raycast, so Fog of War is disabled when either player is inside an interior.
  • No detections. It hides players. It does not detect, flag or ban anyone.
  • No updates and no support. This is a one-time snapshot. New bypasses won't be patched here.

Important: sv_stateBagStrictMode

sentra-fow shares each player's real Z position through state bags. If your server has this in server.cfg:

set sv_stateBagStrictMode true

Fog of War will not work, and it fails silently: every player stays visible. Disable strict mode, or write the realZ value from a server-side script.

Want something that fights back?

Anti-WallHack Lite is a good extra layer, but it is only a layer. Sentra Anticheat includes a hardened Fog of War with server-side verification, active cheat detection, automated bans, screenshot capture, Discord logs and continuous updates against new bypasses.

Get Sentra Anticheat or join us on Discord if you have questions.

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