Image Viewer

A multiloader Minecraft mod/plugin (Fabric / NeoForge / Paper) for 26.1+ that lets server operators display images to players via an in-game web viewer.

The server hosts a local HTTP server that serves images. When a player presses the keybind, their client opens a full-screen browser powered by MCEF to view the images.

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How It Works

1. Server starts → Image web server launches on the configured port
2. Player joins → Server sends the port and category list to the client
3. Player presses I → Browser screen opens, showing images from the server

Clients can connect to any of the supported server platforms — Fabric server, NeoForge server, or a Paper plugin server. The mod is client-optional on Fabric/NeoForge, so the client can also join vanilla/Paper servers without the channel handshake forcing a disconnect.

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Installation

Server

Pick one of:

• Fabric server — install the Fabric jar
• NeoForge server — install the NeoForge jar
• Paper server — drop the Paper plugin jar into plugins/

Client

• Install the Fabric or NeoForge jar

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Server Setup

1. Place Images

Put image files (.png, .jpg, .jpeg) in the server's imageviewer/images/ directory.

<server root>/
└── imageviewer/
    └── images/
        ├── 1.png          ← shown as "Main" category
        ├── 2.png
        └── rules/         ← shown as "rules" category
            ├── 1.png
            └── 2.png

Images are displayed in numerical order (by the number extracted from the filename).

2. Configure the Port

On first launch, imageviewer/config.json is created automatically:

{
  "webServerPort": 25580
}

Value	Behavior
25580	Default fixed port
0	Random available port (not recommended — clients may be blocked by firewall)
Any other number	Use that port

Restart the server after changing the config.

3. Open the Firewall

The HTTP port (default 25580) must be reachable by clients. Open it in the server's firewall in addition to the Minecraft port (default 25565).

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Commands

Command	Permission	Description
/imageviewer reload	Op level 2 (gamemaster)	Re-detect categories and push the updated image list to every online player. Use this after adding/removing images or category subdirectories.

Changing webServerPort still requires a server restart.

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Usage

Action	Result
Press I (configurable)	Open image viewer
Left click	Next image
Right click	Previous image
Left click on last image	Close viewer
Escape	Close viewer

If multiple image categories (subdirectories) exist, a selection screen appears first.

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Categories

Subdirectories inside imageviewer/images/ become selectable categories.

• Images directly in imageviewer/images/ → Main category
• imageviewer/images/rules/ → rules category
• imageviewer/images/event/ → event category

If only one category exists, the selection screen is skipped.

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Dependencies

Dependency	Side	Required
Fabric API	Client (Fabric only)	Yes
MCEF	Client	Bundled (no separate install)