linkfixer: A simple bot to fix URLs in Discord messages

A Discord bot that automatically fixes URLs posted in your server by applying customizable transformations to links from specific domains.

Features

• Domain-Specific Fixes: Configure different fixes for different domains
• Multiple Fixer Types:
  • Replace: Simple string replacement in URLs
  • Regex Replace: Advanced pattern matching with capture groups
  • Prepend: Add prefixes to URLs
• Per-Server Configuration: Each Discord server maintains its own set of URL fixers

Use Cases

Perfect for fixing common URL issues like:

• Converting mobile links to desktop versions
• Adding bypass parameters for paywalled content
• Redirecting through privacy-friendly frontends
• Fixing broken social media embeds

Installation

Docker

Run the latest Docker image using:

docker run carreter/discord-linkfixer-bot -token YOUR_DISCORD_BOT_TOKEN

Pre-built Binaries

Release binaries are also available here.

Building from Source

Install prerequisites

• Go 1.24.4 or later
• Discord bot token

Clone the repository

git clone https://github.com/carreter/discord-linkfixer-bot
cd discord-linkfixer-bot

Build and run the bot

go build -o linkfixer-bot
./linkfixer-bot -token YOUR_DISCORD_BOT_TOKEN

Flags:

• -token YOUR_DISCORD_BOT_TOKEN: Your Discord bot token
• -db PATH: Path to database file (default: ./fixers.db)

Discord Commands

/replace-fixer

Register a simple string replacement fixer.

• domain: The domain to apply this fixer to
• old: Substring to replace
• new: Replacement substring

Example: Fix Twitter mobile links

/replace-fixer domain:twitter.com old:mobile.twitter.com new:twitter.com

/regexp-replace-fixer

Register a regex-based fixer with capture groups.

• domain: The domain to apply this fixer to
• pattern: Regular expression pattern
• replacement: Replacement string (use $1, $2, etc. for capture groups)

Example: Convert Reddit mobile links

/regexp-replace-fixer domain:reddit.com pattern:m\.reddit\.com replacement:old.reddit.com

/prepend-fixer

Add a prefix to URLs from a domain.

• domain: The domain to apply this fixer to
• prefix: String to prepend to the URL

Example: Add privacy redirect

/prepend-fixer domain:youtube.com prefix:https://invidio.us/

/list-fixers

List all registered fixers for the current server.

/delete-fixer

Remove a fixer for a specific domain.

• domain: Domain of the fixer to delete

/register-csv-fixers

Register fixers from a CSV file attachment.

Currently, rows can haven one of two formats:

1. prepend,<domain>,<prefix>, or
2. replace,<domain>,<old>,<new>

These correspond to the /prepend-fixer and /replace-fixer commands, respectively.

Development

Project Structure

├── main.go                          # Entry point
├── pkg/
│   ├── fixer/                      # URL fixer implementations
│   │   ├── fixer.go               # Fixer interfaces and types
│   │   └── store.go               # BoltDB storage layer
│   └── linkfixerbot/              # Discord bot implementation
│       ├── bot.go                 # Main bot logic
│       └── commands/              # Slash command handlers

License

MIT License - see LICENSE file for details.

Contributing

Contributions welcome! Please open an issue or submit a pull request.