Modrinth Modpack Downloader

A Python script to download mods from Modrinth modpacks with support for downloading all mods or only server-side compatible mods.

Features

• Download all mods from a Modrinth modpack
• Server-only mode: Download only server-compatible mods
• Interactive version selection
• Customizable output directory
• Overwrite protection with user confirmation
• Progress tracking and download summary

Installation

1. Install Python 3.6 or higher
2. Install dependencies:

pip install -r requirements.txt

Usage

Basic Usage

Download all mods from a modpack:

python download_mods.py t1tOiUHZ

Server-Only Mode

Download only server-side compatible mods:

python download_mods.py t1tOiUHZ --mode server

Custom Output Directory

Specify a custom output directory:

python download_mods.py t1tOiUHZ --output ./server-mods

Combined Options

python download_mods.py t1tOiUHZ --mode server --output ./my-server-mods

Command-Line Arguments

• modpack_id (required): The Modrinth modpack ID (e.g., t1tOiUHZ)
• -m, --mode: Download mode
  • all (default): Download all mods
  • server: Download only server-compatible mods
• -o, --output: Output directory for downloaded mods (default: mods)

How It Works

1. Fetch Versions: The script fetches all available versions of the modpack from Modrinth's API
2. Version Selection: You interactively select which version to download
3. Download Modpack: The script downloads the .mrpack file and extracts the mod list
4. Filter Mods: Based on the mode, it filters which mods to download
   • all mode: Downloads all mods
   • server mode: Only downloads mods with server support (required or optional)
5. Download Mods: Downloads each mod file, asking for confirmation if files already exist
6. Summary: Displays a summary of downloaded and skipped mods

Example Output

Modrinth Modpack Downloader
Modpack ID: t1tOiUHZ

Available versions:
------------------------------------------------------------
1. 1.20.1-0.1.0 - My Modpack v0.1.0
2. 1.20.1-0.0.9 - My Modpack v0.0.9
------------------------------------------------------------

Select version (1-2): 1

Downloading modpack from: https://...
Extracting modpack index...

Downloading mods to: C:\Users\Target\Documents\Modrinth-Server-Mod-Downloader\mods
Mode: server
------------------------------------------------------------
[1/50] Downloading: fabric-api-0.92.0.jar... ✓
[2/50] Downloading: sodium-mc1.20.1-0.5.5.jar... ✓
...
------------------------------------------------------------

Download Summary:
  Total mods in modpack: 50
  Successfully downloaded: 35
  Skipped: 15

Done!

Error Handling

The script handles various error cases:

• Invalid modpack IDs
• Network errors
• Missing or corrupted files
• User interruption (Ctrl+C)

License

This project is provided as-is for educational and personal use.