Mod checker

Mod Checker is a server-side administration tool for Fabric/Quilt that gives server owners complete control over which mods players can use. It validates the mod list of every connecting player against a customizable whitelist or banlist, helping to maintain stability, security, and the intended gameplay experience on your modded server.

🛡️ Core Features

• Dual Moderation Modes: Operate in flexible whitelist mode (allow only listed mods) or banlist mode (allow everything except listed mods).
• Automatic Validation: Automatically checks all connecting players. No manual commands are needed.
• Kick with Clear Messages: Players with unauthorized or missing required mods (like Mod Checker itself) are disconnected with informative, customizable messages.
• Simple File-Based Configuration: All rules are managed through a straightforward modcheck.json file in your server's config folder.
• Player Locale Detection: Kick messages are automatically shown in English or Russian based on the player's client language.

⚙️ How It Works & Configuration

1. Installation: Place modcheck.jar in your server's mods folder (Fabric/Quilt required).
2. Configuration: On first run, a modcheck.json file is generated in the config folder. Edit it to set the mode ("whitelist" or "banlist") and list the mod IDs under "mods".
3. Automatic Enforcement: Once configured, the mod runs automatically. Players joining without the required modcheck client mod or with disallowed mods will be denied access.

Minimum modcheck.json (Whitelist Mode):

{
  "mode": "whitelist",
  "mods": [
    "fabric-api-base",
    "fabric-api-lookup-api-v1",
    "fabric-biome-api-v1",
    "fabric-block-api-v1",
    "fabric-blockrenderlayer-v1",
    "fabric-client-tags-api-v1",
    "fabric-command-api-v1",
    "fabric-command-api-v2",
    "fabric-commands-v0",
    "fabric-containers-v0",
    "fabric-content-registries-v0",
    "fabric-convention-tags-v1",
    "fabric-crash-report-info-v1",
    "fabric-data-generation-api-v1",
    "fabric-dimensions-v1",
    "fabric-entity-events-v1",
    "fabric-events-interaction-v0",
    "fabric-events-lifecycle-v0",
    "fabric-game-rule-api-v1",
    "fabric-item-api-v1",
    "fabric-item-group-api-v1",
    "fabric-key-binding-api-v1",
    "fabric-keybindings-v0",
    "fabric-lifecycle-events-v1",
    "fabric-loot-api-v2",
    "fabric-loot-tables-v1",
    "fabric-message-api-v1",
    "fabric-mining-level-api-v1",
    "fabric-model-loading-api-v1",
    "fabric-models-v0",
    "fabric-networking-api-v1",
    "fabric-networking-v0",
    "fabric-object-builder-api-v1",
    "fabric-particles-v1",
    "fabric-recipe-api-v1",
    "fabric-registry-sync-v0",
    "fabric-renderer-api-v1",
    "fabric-renderer-indigo",
    "fabric-renderer-registries-v1",
    "fabric-rendering-data-attachment-v1",
    "fabric-rendering-fluids-v1",
    "fabric-rendering-v0",
    "fabric-rendering-v1",
    "fabric-resource-conditions-api-v1",
    "fabric-resource-loader-v0",
    "fabric-screen-api-v1",
    "fabric-screen-handler-api-v1",
    "fabric-sound-api-v1",
    "fabric-transfer-api-v1",
    "fabric-transitive-access-wideners-v1",
    "mixinextras"
  ]
}

❓ FAQ

• Q: Do players need to install this mod?
  • A: Yes! For the check to work, the mod must be installed on both the server AND the client. Players without it will be kicked.
• Q: Is Fabric API required?
  • A: Absolutely. This mod depends on Fabric API.
• Q: Can I use it on Quilt?
  • A: Yes, it is compatible with Quilt, thanks to Fabric API compatibility layers.
• Q: How do I find a mod's ID for the config?
  • A: Check the mod's fabric.mod.json file or its documentation. It's usually the "id" field (e.g., xaerominimap).

📜 Technical & License

• License: MIT License. You are free to use, modify, and distribute this mod.
• Source Code: https://github.com/VladKagaykin/mod_checker
• Support: Please report any issues or suggestions on the project's issue tracker.

Maintain a fair and stable modding environment with Mod Checker — the essential gatekeeper for your server.