Grabby - Media Embedding Discord Bot

A Discord bot that downloads and embeds media from URLs directly into Discord messages using yt-dlp and gallery-dl. Features slash commands, auto-embed channels, metadata extraction, and user-controlled deletion.

Features

• Media Download: Downloads media from URLs using yt-dlp and gallery-dl (priority order: gallery-dl → yt-dlp)
• In-Memory Processing: Downloads media directly to memory and uploads to Discord (no disk I/O)
• Slash Command: /embed command with options for URL, custom message, and spoiler mode
• Auto-Embed Channels: Automatically processes URLs in configured channels without commands
• Metadata Extraction: Displays title, author, likes, and original URL with downloaded files
• File Size Limits: Enforces Discord's 25MB file size limit with user feedback
• Auto-Resize: Automatically resizes oversized media files using ffmpeg to fit Discord's 25MB limit
• Reaction Deletion: ❌ emoji reaction allows original poster or admins to delete embeds

Installation

Docker

Docker images are available on Docker Hub:

https://hub.docker.com/repository/docker/amadejkastelic/grabby

Pull the latest image:

docker pull amadejkastelic/grabby:latest

Run the bot:

docker run -d \
  -v /path/to/config.toml:/config.toml \
  -e DISCORD_TOKEN=your_bot_token_here \
  amadejkastelic/grabby:latest

GitHub Container Registry

Multi-architecture images are also available on ghcr:

docker pull ghcr.io/amadejkastelic/grabby:latest

Nix

Install and run using Nix flakes:

# Run without cloning
nix run github:amadejkastelic/grabby --accept-flake-config

# Build the package
nix build .#grabby

# Run the package
nix run .#grabby

# Enter development shell
nix develop

# Build Docker image
nix build .#docker

Cachix Cache

The project uses Cachix to cache build outputs, speeding up Nix builds.

To configure Cachix on NixOS, add this to your configuration:

{
  nix.settings = {
    substituters = ["https://amadejkastelic.cachix.org"];
    trusted-public-keys = ["amadejkastelic.cachix.org-1:EiQfTbiT0UKsynF4q3nbNYjNH6/l7zuhrNkQTuXmyOs="];
  };
}

NixOS Module

On NixOS systems, you can configure grabby as a system service:

# flake.nix
{
  inputs.grabby.url = "github:amadejkastelic/grabby";
  # ... other inputs

  outputs = { self, nixpkgs, grabby, ... }: {
    nixosConfigurations.yourHostname = nixpkgs.lib.nixosSystem {
      system = "x86_64-linux";
      modules = [
        ./configuration.nix
        grabby.nixosModules.grabby
      ];
    };
  };
}

# configuration.nix
{ config, pkgs, ... }: {
  services.grabby = {
    enable = true;
    logLevel = "info";
    environmentFile = config.sops.secrets.discord-token.path;

    servers = [
      {
        serverId = "123456789";
        autoEmbedChannels = [
          "channel1"
          "channel2"
        ];
        embedEnabled = true;
      }
    ];
  };

  # If using sops
  sops.secrets.discord-token = {
    owner = config.services.grabby.user;
    group = config.services.grabby.group;
  };
}

Configuration

Config File Locations

Configuration is loaded from one of these locations (in order of priority):

1. CLI argument: grabby --config /path/to/config.toml
2. Environment variable: CONFIG_FILE=/path/to/config.toml
3. XDG config directory: $XDG_CONFIG_HOME/grabby/config.toml
4. Default home directory: ~/.config/grabby/config.toml

Config Options

# Discord configuration (optional)
[discord]
# Bot token (will use DISCORD_TOKEN env var if not set)
# token = "your_bot_token_here"

# Logging configuration (optional)
[logging]
# Format: "json" or "pretty" (default: "json")
format = "json"
# Level: "trace", "debug", "info", "warn", "error" (default: "info")
level = "info"

[[servers]]
server_id = "YOUR_DISCORD_SERVER_ID"
auto_embed_channels = [
  "CHANNEL_ID_1",
  "CHANNEL_ID_2"
]
embed_enabled = true

# Add more servers by repeating the [[servers]] section
# [[servers]]
# server_id = "ANOTHER_SERVER_ID"
# auto_embed_channels = ["CHANNEL_ID_3"]
# embed_enabled = false

Environment Variables

• DISCORD_TOKEN: Discord bot token (optional if set in config file)
• CONFIG_FILE: Path to config file (optional)

Usage

Slash Command

Use the /embed command to embed media:

/embed url:https://example.com/video.mp4

Options:

• url: The URL to download and embed
• message: Optional custom message to include
• spoiler: Mark the content as a spoiler (default: false)

Auto-Embed Channels

Configure channels for automatic embedding in your config file. Any URL posted in these channels will be automatically embedded without requiring the /embed command.

Reaction Deletion

React with ❌ to delete an embed. Only the message author or users with MANAGE_MESSAGES permission can delete embeds.

Development

# Run the bot in development mode
cargo run

# Run tests
cargo test

# Check code formatting
cargo fmt --check

# Run clippy lints
cargo clippy -- -D warnings

# Build release version
cargo build --release

Nix Development

# Enter development environment with pre-commit hooks
nix develop

# Run pre-commit checks
nix run .#checks.pre-commit-check

Architecture

• Discord Integration: Twilight async Discord library with gateway and HTTP clients
• Media Download: Abstraction layer supporting multiple downloaders (yt-dlp, gallery-dl)
• Async Runtime: Tokio for all async operations
• Cache: In-memory caching for Discord objects
• Config: Server/channel configuration for auto-embed channels