# MCL Skin **A skin for your offline nickname, inside the game itself.** MCL Skin is the in-game half of **TCLauncher**. On its own it does exactly one thing: it takes a PNG that is already in the right folder, under the right name and in the right format, and shows it on your character. Everything that gets the PNG there is TCLauncher's job: finding the skin, converting it, checking it, naming it, and installing the right mod file for your loader and game version. > **Important:** the mod still works without TCLauncher, but it gives you a lot less. You have to do the launcher's job yourself, by hand, every time you change your skin. ## What the mod does Vanilla Minecraft can only fetch a skin from Mojang's servers, and those servers don't know your offline nickname. Offline players are stuck as Steve or Alex. This mod fixes that, and only that. - Reads `/mclskin/skins/.png` - Also reads `/CustomSkinLoader/LocalSkin/skins/.png`, for people coming from CustomSkinLoader - Shows that image on your character in game One file in, one skin out. **Without TCLauncher:** you create that file yourself. You find a skin, check its format, rename it to match your nickname exactly, find the instance folder, create the two folders and drop the file in. If any of those steps is wrong, you stay Steve and nothing tells you why. TCLauncher does all of it in one click. ## Skin formats - **64x64** is the modern layout - **HD** skins are 128x128, 256x256 or any other multiple of 64 - **64x32** is the old pre-1.8 layout, which is still supported The mod works out slim or classic arms from the image itself. A slim skin leaves two pixel columns of the right arm empty, and the mod checks exactly those, on both the front face and the outer side. **Without TCLauncher:** the mod reads these formats but doesn't convert anything, and it only accepts PNG. A JPG, BMP, GIF or a skin with the wrong proportions won't show up, and you won't get an error. TCLauncher accepts PNG, JPG, BMP and GIF, scales them to 64x64 with nearest-neighbour (so the second layer keeps hard edges), converts 64x32 to the modern layout, works out slim or classic, and rejects images that aren't skins, telling you why. ## Live reload - The file is checked about once a second. - The check uses the modification time together with the file size, because a copied file often keeps its original timestamp. - Replace the PNG and the new skin appears without restarting the game. **Without TCLauncher:** you swap files by hand while the game is running. TCLauncher lets you choose from a skin library and rotate a 3D preview first. ## Works on every loader *New in 1.4.* - Until 1.4 the skin reliably showed up only on Quilt and on Fabric for 26.x. Forge refused the mod file outright (its manifest used NeoForge-only fields), and even then it never enabled the mod's hooks. NeoForge loads authlib, the library the mod used to hook, where mods cannot change it, so the hook silently never ran. Fabric and Quilt on 1.20.3–1.21.8 crashed on startup, because the mod called a method that only newer authlib versions have. Forge and NeoForge also start the game with IPv6 preferred, and the local skin address came out in a form the game rejects. - The mod now hooks the game's own skin manager, finding the calls into authlib by their names, which are never obfuscated. The same code works on Fabric, Quilt, Forge and NeoForge. ## Other players' skins *New in 1.4.* When TCLauncher is signed into its online profile, it uploads the skin you choose for your offline nickname, and other players who use TCLauncher see it on the same server. You see theirs too. - The mod only asks for players whose profile has no skin of its own, as on offline-mode servers. A real Mojang skin is never replaced. - It asks `/api/skins/`, where `` is the address TCLauncher writes into `settings.json`. If there's no address, the mod never touches the network. - Requests run in the background, with short timeouts, at most once every few minutes per nickname. The game never waits for them. If anything fails, that player keeps the default skin. - Downloaded skins are cached in `/mclskin/cache/` under their hash, so a familiar skin appears at once, and the image is only downloaded again when it changes. - Your own skin still comes straight from your disk. It shows up instantly and also works offline. - A nickname belongs to one TCLauncher profile. If someone else already uses yours, TCLauncher tells you, and only you will see your skin. **Without TCLauncher:** other players can't see your skin. Only the launcher can upload it, and only the launcher tells the mod where to look for everyone else's. ## Capes *New in 1.5.* - Reads `/mclskin/capes/.png`, a standard 64x32 cape (HD multiples work too) - The cape shows on your back, and the game draws elytra with the same picture - With TCLauncher signed in, other TCLauncher players see your cape on the same server, and you see theirs. The mod asks `/api/capes/` the same careful way it asks for skins: in the background, with short timeouts, cached by hash - A real Mojang cape is never replaced. The mod only fills in a cape for players who have none **Without TCLauncher:** you draw or find a 64x32 cape and drop it into that folder yourself. TCLauncher has a cape catalog, a cape editor and a 3D preview, and puts the file in place for you. ## Skin transparency *New in 1.0.2.* - A slider in **Options → Skin Customization**. - 0% is a normal skin, 100% is fully invisible, and anything in between is a ghost. - The value is saved in `/mclskin/settings.json`. The transparency is multiplied into the image's alpha channel before the game ever sees it. Nothing in the game's rendering is changed, so it works the same on every version and every loader. Notes: - The game caches a player's skin for the session, so a change made while you're in a world applies after you rejoin. If you set it from the main menu, it applies right away. - On the old 64x32 layout, the game makes the body opaque when it converts the layout, so transparency has no effect there. - Slim or classic is decided from the original image, never from the transparent copy. This slider is the only thing the mod adds to the game's interface. ## Startup notice The first screen after the game starts shows a panel, in your language, explaining that the mod has far fewer features without TCLauncher. - Close it with the **Close** button, **Esc** or **Enter**. - Tick **Do not show again** and it won't come back (the choice is saved in `settings.json`). ## Languages The mod supports 15 languages, the same ones TCLauncher supports: Ukrainian, English, Russian, Belarusian, Polish, Czech, Romanian, Spanish, French, German, Italian, Turkish, Japanese, Chinese, Filipino. - The language follows the game's own setting from `options.txt`. - If the game's language isn't on the list, or `options.txt` can't be read, the mod uses English. - The setting is checked every two seconds, so switching the game's language updates the mod's text without a restart. ## How the skin reaches the game The game doesn't accept a skin as a file. It only accepts a URL, and its image loader only speaks HTTP, so a `file://` path won't work. The mod works around this: - It starts a tiny HTTP server on the loopback address `127.0.0.1`, on a port the operating system picks. Nothing outside your computer can reach it. - It serves the image under a name that is a hash of the image's contents. When the skin changes, the address changes too, so the game fetches the new skin instead of showing the old one from its cache. - The game checks skin URLs against a list of allowed Mojang domains. The mod doesn't switch that check off. It unpacks only its own skin descriptions itself and leaves every other skin to the game's usual check. - The game shows another player's skin only if it's marked as signed. The mod marks the skins it supplies, from your disk or from TCLauncher, so that other players' skins aren't replaced with the default one. What the mod does **not** do: - It never replaces a real Mojang skin or cape. - It never uploads anything. Your skin goes to TCLauncher's server only through the launcher, and only while the launcher is signed in. - On the network, the mod only downloads other players' skins and capes, and only when TCLauncher has configured a server. Each request contains just that player's nickname. ## Compatibility - **Loaders:** Fabric, Forge, NeoForge, Quilt - **Versions:** Minecraft 1.14 to 26.3 - **156 files**, one for each loader and version pair - **Client side only.** Servers don't need it. - Requires a mod loader. It doesn't work in pure vanilla. The mod uses no mappings and never refers to a game method by name. Its hooks are placed by method signature and by the authlib calls the game makes, which is why three builds cover about fifty game versions and four loaders. If a version comes along whose methods it doesn't recognise, the mod skips its interface additions and skins keep working. It won't crash the game. **Without TCLauncher:** you have to pick the right file out of 156 yourself. If you pick the wrong one, it won't load and won't tell you much. TCLauncher knows each instance's loader and version and installs the matching file itself. ## What TCLauncher adds These features are part of the launcher, not the mod: - A skin library that keeps all your skins in one place and works offline - A full 3D model preview you can rotate with the mouse - **Take by nickname:** get any licensed player's skin from Mojang's public API - Add a skin from a file, or drag an image into the window - Automatic conversion of PNG, JPG, BMP and GIF, including 64x32 → 64x64 and HD rescaling - A clear error message when an image isn't a skin - Installing the mod itself into the right instance, in the right build - For Microsoft accounts, uploading the skin to Minecraft's own skin service so that every player on licensed servers sees it - For offline nicknames, uploading the skin to TCLauncher's server so that other TCLauncher players see it, and telling the mod where to fetch theirs - Removing a skin from an instance without hunting for the file ## Files it creates | Path | Contents | |---|---| | `/mclskin/skins/.png` | Your skin (placed there by TCLauncher) | | `/mclskin/capes/.png` | Your cape (placed there by TCLauncher) | | `/mclskin/settings.json` | Transparency level, whether the startup notice was dismissed, and the server address written by TCLauncher | | `/mclskin/cache/` | Other players' skins and capes, saved under their hash, and a list of which nickname uses which | Nothing else is written. The mod never uploads anything. It only downloads other players' skins and capes, and only from the server TCLauncher has configured. --- MCL Skin 1.5 is part of TCLauncher. Author: tcleo. Client side only. All rights reserved.

Tcleo