Fleasion Glossary

If a word in one of our guides made you stop and go "wait, what's that?", it's here. These are the terms that come up when you use Fleasion — the app's own features, the Roblox pieces it touches, and the technical bits under the hood — each in plain English, with links to where they matter.

Core concepts

Asset — Any file Roblox loads to build a game: a sound, texture, mesh, animation or image. Fleasion works by swapping or removing these on your own machine. What is Fleasion?

Asset ID — The number that identifies a specific asset (the digits in an rbxassetid:// link). Fleasion matches on these IDs to know which asset to replace.

Proxy (local proxy) — A small server that runs on your own computer at 127.0.0.1 and sits between Roblox and the internet. Roblox's asset requests pass through it, and Fleasion rewrites them before they reach the game. This is the whole idea behind the tool — nothing runs on Roblox's servers. How it works

Interception — Catching a Roblox asset request as it happens so it can be redirected, swapped or blocked. Fleasion intercepts requests to Roblox's asset hosts and answers them itself.

Client-side — A change that exists only on your machine and only on your screen. Fleasion is entirely client-side — it never changes anything for other players or on Roblox's servers. Is Fleasion safe?

Cosmetic asset swap — A Replacer rule that changes how an existing asset looks or sounds on your client. It cannot aim, add items or read game memory. Do not apply that label automatically to custom FastFlags or edited proxy traffic. Is Fleasion safe?

The dashboard tabs

Replacer — The main tab, where you map an original asset to the replacement you want. This is where most of your work happens.

Scraper — A tool that pulls the asset IDs out of a game so you can see what's there and target it — handy for games we don't ship a preset for. Supported games

Modifications — Built-in, ready-made tweaks you can toggle on without setting up rules by hand.

Subplace Joiner — A utility for joining specific subplaces and reserved servers directly.

Miscellaneous — Extra tools and account utilities that don't fit the other tabs.

Proxy tab — The v2.4.0 live traffic workspace. It can filter and highlight flows, inspect bodies, hold/edit traffic, replay a request, and forward or drop it. It can expose login data, so never stream or share it unredacted. v2.4.0 update

Settings — Theme, Env Proxy or legacy Hosts File mode, per-user Run on Boot, cache automation and other app preferences.

Asset types you'll swap

Texture — The 2D image painted onto a 3D surface. Swapping textures is how you re-skin guns, walls and characters. No arms / no textures

TexturePack — A grouped set of texture replacements, aware of ORM channels (see below), used to re-skin things cleanly in one go.

Mesh — The 3D shape of an object. Removing or replacing a mesh is how tricks like "no arms" work. No arms / no textures

Skybox — The image wrapped around the sky and horizon. Swap it to change the whole mood of a map. Custom skyboxes

Sound — Any audio asset — gunshots, music, footsteps. Replace them with your own clips. Custom sounds

Animation — The motion data for a rig. Fleasion can strip or convert animations, including to curve animations (see below).

Files, presets & sharing

Preset — A ready-made bundle of swaps for a specific game, so you get a full look without building it yourself. We ship presets for six games out of the box. Presets & configs

Config — A saved file of your own rules. Export it to back up or share your setup; import one (or drag it into the folder) to load someone else's. Presets & configs

Portable config path — A leading-slash local reference such as /Sounds/hit.ogg, resolved inside the config's asset folder instead of one user's home directory. v2.4.0 supports nesting up to 10 levels and watches external config changes.

Under the hood

Env Proxy — The v2.4.0 default routing mode. Fleasion launches Roblox Player or Sober with proxy environment variables aimed at a high loopback port. It does not edit the hosts file or need port 443; Studio is untouched.

Hosts File mode — The optional legacy compatibility route. It maps Roblox asset domains to localhost and uses privileged port 443, so it has broader system impact than Env Proxy.

assetdelivery.roblox.com / fts.rbxcdn.com — The Roblox endpoints that hand out assets. These are the hosts Fleasion intercepts.

CA certificate (cacert.pem) — A trust certificate Fleasion generates and patches into Roblox's own CA bundle so its HTTPS connection to the local proxy is trusted. Env Proxy still needs this Roblox-local step; it is not a system-wide root certificate. Install guide

Cache (Roblox cache) — Where Roblox stores assets it has already downloaded. Because a cached asset won't be re-fetched, you clear the cache (or restart Roblox) after a change so your swap actually downloads and shows up. This is the step people miss most. How to use Fleasion

System tray — The small icon area (bottom-right on Windows) where Fleasion lives after launch. Right-click the icon to reopen the Dashboard. Install guide

R6 / R15 — The two Roblox avatar rigs — R6 has six body parts, R15 has fifteen. It matters when you're converting animations.

Curve animation — A newer Roblox animation format. Fleasion can convert R6/R15 animations to it. Changelog

ORM channels — A way textures pack Occlusion, Roughness and Metallic data together. TexturePack replacement is ORM-aware so re-skins keep the right surface look.

RBXM / RBXMX / OBJ / GLB — Model formats Fleasion can preview, import, convert or export. OBJ is useful for static geometry; v2.4.0 can export a captured rig, skin weights and mesh together as one GLB.

GPL-3.0 — The open-source license Fleasion is released under. It's why you can read every line of the code, or build your own copy. About the team

Roblox ecosystem terms

Sober — A Flatpak build of the Roblox client for Linux. It's how Fleasion runs on Linux. Install guide

Strap / bootstrapper (Bloxstrap, Fishstrap) — Third-party launchers people use to start Roblox with custom settings. They're separate from Fleasion, but often used alongside it — some setups also tweak a fast flag there so the proxy behaves.

Fast flags (FFlags) — Internal Roblox client settings. Fleasion can manage built-in and custom flags with JSON profiles, import/export and bindings. Custom flags can be bannable; successful application does not make them allowed. FastFlags guide

StyLiS Studios — The studio behind Phantom Forces, one of the games our community customizes most. Fleasion for Phantom Forces

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Related: What is Fleasion? · How to use it · Install & run · Presets & configs