mkbrr

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mkbrr is a command-line tool to create and inspect torrent files. Fast, single binary, no dependencies. Written in Go.

Table of Contents

• Installation
  • Prebuilt Binaries
  • Homebrew
  • Go Install
  • Build from Source
• Usage
  • Create a Torrent
    • Single Mode
    • Batch Mode
    • Preset Mode
    • Create Flags
    • Batch Configuration Format
    • Preset Configuration Format
  • Inspect a Torrent
  • Modify a Torrent
  • Version Information
  • Update
• Performance
• License

Installation

Prebuilt Binaries

Download the latest release from the releases page.

Homebrew

brew tap autobrr/mkbrr
brew install mkbrr

Go Install

If you have Go installed:

go install github.com/autobrr/mkbrr@latest

Build from Source

Requirements:

• Go 1.23.4 or later

# Clone the repository
git clone https://github.com/autobrr/mkbrr.git
cd mkbrr

# Build the binary to ./build/mkbrr
make build

# Install the binary to $GOPATH/bin
make install

# Or install system-wide (requires sudo)
sudo make install    # installs to /usr/local/bin

The build process will automatically include version information and build time in the binary. The version is determined from git tags, defaulting to "dev" if no tags are found.

Usage

Create a Torrent

mkbrr create [path] [flags]

Single Mode

Create a torrent from a single file or directory:

mkbrr create path/to/file -t https://please.passthe.tea

Batch Mode

Create multiple torrents using a YAML configuration file:

mkbrr create -b batch.yaml

Example batch.yaml:

version: 1
jobs:
  - output: ubuntu.torrent
    path: /path/to/ubuntu.iso
    trackers:
      - https://tracker.openbittorrent.com/announce
    webseeds:
      - https://releases.ubuntu.com/22.04/ubuntu-22.04.3-desktop-amd64.iso
    comment: "Ubuntu 22.04.3 LTS Desktop AMD64"
    private: false
    # piece_length is automatically optimized based on file size:
    # piece_length: 22  # manual override if needed (2^n: 14-24)
    # max_piece_length: 23  # limits the automatically calculated maximum piece length

  - output: release.torrent
    path: /path/to/release
    trackers:
      - https://tracker.openbittorrent.com/announce
    private: true
    source: "GROUP"
    comment: "My awesome release"
    no_date: false

Batch mode will process all jobs in parallel (up to 4 concurrent jobs) and provide a summary of results.

Preset Mode

Create torrents using predefined settings from a preset configuration:

# Use a preset from a config file
mkbrr create -P private path/to/file

# Use a preset from a custom config file
mkbrr create -P emp --preset-file custom-presets.yaml path/to/file

# Override preset settings with command line flags
mkbrr create -P private --source "CUSTOM" path/to/file

Tip

The preset file is searched for in the following locations (in order):

1. File specified by --preset-file flag
2. presets.yaml in the current directory
3. ~/.config/mkbrr/presets.yaml in the user's home directory
4. ~/.mkbrr/presets.yaml in the user's home directory

Example presets.yaml:

version: 1

# Defaults that always apply
default:
  private: true
  no_date: true

presets:
  # opentrackr preset
  ptp:
    source: "PTP"
    trackers:
      - "https://please.passthe.tea/announce"
    # piece_length is automatically optimized based on file size
    # piece_length: 20  # manual override if needed (2^n: 14-24)
    # max_piece_length: 23  # limits the automatically calculated maximum piece length

  # Public tracker preset
  public:
    private: false  # overrides default preset
    trackers:
      - "udp://tracker.opentrackr.org:1337/announce"
      - "udp://open.tracker.cl:1337/announce"
      - "udp://9.rarbg.com:2810/announce"
    # piece_length is automatically optimized based on file size
    # piece_length: 22  # manual override if needed (2^n: 14-24)
    # max_piece_length: 23  # limits the automatically calculated maximum piece length

Create Flags

General flags:

• -b, --batch <file>: Use batch configuration file (YAML)
• -P, --preset <name>: Use preset from config
• --preset-file <file>: Preset config file (default: ~/.config/mkbrr/presets.yaml)
• -v, --verbose: Be verbose

Single mode flags:

• -t, --tracker <url>: Tracker URL

• -w, --web-seed <url>: Add web seed URLs (can be specified multiple times)

• -p, --private: Make torrent private (default: true)

  [!NOTE] To create a public torrent, use --private=false or -p=false. Using just -p will set private to true.

• -c, --comment <text>: Add comment

• -l, --piece-length <n>: Set piece length to 2^n bytes (14-24, automatic if not specified). Note: if this flag is set, it will always override any value specified with -m, --max-piece-length.

• -m, --max-piece-length <n>: Limit maximum piece length to 2^n bytes (14-24)

• -o, --output <path>: Set output path (default: .torrent)

• -s, --source <text>: Add source string

• -d, --no-date: Don't write creation date

Note: When using batch mode (-b), torrent settings are specified in the YAML configuration file instead of command line flags. When using preset mode (-P), command line flags will override the preset settings.

Batch Configuration Format

The batch configuration file uses YAML format with the following structure:

# yaml-language-server: $schema=https://raw.githubusercontent.com/autobrr/mkbrr/main/schema/batch.json
version: 1  # Required, must be 1
jobs:       # List of torrent creation jobs
  - output: string         # Required: Output path for .torrent file
    path: string           # Required: Path to source file/directory
    trackers:              # Optional: List of tracker URLs
      - string
    webseeds:              # Optional: List of webseed URLs
      - string
    private: bool          # Optional: Make torrent private (default: true)
    piece_length: int      # Optional: Piece length exponent (14-24)
    max_piece_length: int  # Optional: Limits the automatically calculated maximum piece length
    comment: string        # Optional: Torrent comment
    source: string         # Optional: Source tag
    no_date: bool          # Optional: Don't write creation date (default: false)

Preset Configuration Format

The preset configuration file uses YAML format with the following structure:

# yaml-language-server: $schema=https://raw.githubusercontent.com/autobrr/mkbrr/main/schema/presets.json
version: 1    # Required, must be 1

# Optional: Default settings that apply to all presets unless overridden
default:
  private: true
  no_date: true
  trackers:
    - string
  # ... other settings as needed

presets:      # Map of preset names to their configurations
  preset-name:
    trackers:              # Optional: List of tracker URLs (overrides default)
      - string
    webseeds:              # Optional: List of webseed URLs (overrides default)
      - string
    private: bool          # Optional: Make torrent private (overrides default)
    piece_length: int      # Optional: Piece length exponent (14-24)
    max_piece_length: int  # Optional: Limits the automatically calculated maximum piece length
    comment: string        # Optional: Torrent comment (overrides default)
    source: string         # Optional: Source tag (overrides default)
    no_date: bool          # Optional: Don't write creation date (overrides default)

Any settings specified in a preset will override the corresponding default settings. This allows you to set common values in the default section and only specify differences in individual presets.

Example presets.yaml:

version: 1

# Defaults that always apply unless overridden
default:
  private: true
  no_date: true

presets:
  # opentrackr preset
  ptp:
    source: "PTP"
    trackers:
      - "https://please.passthe.tea/announce"
    # piece_length is automatically optimized based on file size
    # piece_length: 20  # manual override if needed (2^n: 14-24)
    # max_piece_length: 23  # limits the automatically calculated maximum piece length

  # Public tracker preset
  public:
    private: false  # overrides default preset
    trackers:
      - "udp://tracker.opentrackr.org:1337/announce"
      - "udp://open.tracker.cl:1337/announce"
      - "udp://9.rarbg.com:2810/announce"
    # piece_length is automatically optimized based on file size
    # piece_length: 22  # manual override if needed (2^n: 14-24)
    # max_piece_length: 23  # limits the automatically calculated maximum piece length

Inspect a Torrent

mkbrr inspect <torrent-file>

The inspect command displays detailed information about a torrent file, including:

• Name and size
• Number of pieces and piece length
• Private flag status
• Info hash
• Tracker URL(s)
• Creation information
• Magnet link
• File list (for multi-file torrents)

Modify a Torrent

mkbrr modify [torrent files...] [flags]

The modify command allows batch modification of existing torrent metadata without requiring access to the source files. Original files are preserved and new files are created with -[preset] or -modified suffix in the same directory as the input files (unless --output-dir is specified).

# Modify a single torrent using a preset (outputs to same directory)
mkbrr modify -P public original.torrent

# Modify multiple torrents using a preset
mkbrr modify -P private file1.torrent file2.torrent

# Modify all torrent files in current directory
mkbrr modify -P public *.torrent

# Specify a different output directory
mkbrr modify -P public --output-dir /path/to/output *.torrent

Modify Flags

• -P, --preset <name>: use preset from config (if you prefer presets, you can use this just like with create)
• --preset-file <file>: preset config file (default: ~/.config/mkbrr/presets.yaml)
• --output-dir <dir>: output directory for modified files (default: same directory as input files)
• -n, --dry-run: show what would be modified without making changes
• -v, --verbose: be verbose

If you don't want to use presets, you can modify individual metadata fields with these flags:

• -t, --tracker <url>: tracker URL override
• -w, --web-seed <url>: add web seed URLs (can be specified multiple times)
• -p, --private: make torrent private (default: true)

  [!NOTE] To create a public torrent, use --private=false or -p=false. Using just -p will set private to true.

• -c, --comment <text>: add comment to the torrent
• -s, --source <text>: specify source string
• -d, --no-date: don't update creation date

Note: Changes that would require access to the source files (like modifying piece length) are not supported. If you need to change these parameters, please create a new torrent instead.

Version Information

mkbrr version

Displays the version and build time of mkbrr.

Update

mkbrr update

Self-updates the mkbrr binary if there is a new version available.

Performance

mkbrr is blazingly fast, matching, and sometimes outperforming other popular torrent creation tools. Here are some benchmarks:

76GB Remux (Single File) [Ryzen 5 3600 / HDD]

# mktorrent
time mktorrent -p
Duration: 98.45s user 41.83s system 51% cpu 4:32.48 total

# mkbrr
time mkbrr create -p
Duration: 74.16s user 36.52s system 56% cpu 3:17.26 total

3.6GB Episode (Single File) [Apple Silicon M3 / NVME]

# mktorrent
time mktorrent -p
Duration: 1.34s user 0.49s system 103% cpu 1.766 total

# mkbrr
time mkbrr create -p
Duration: 1.27s user 0.67s system 122% cpu 1.587 total

350MB Music Album (15 Files) [Apple Silicon M3 / NVME]

# mktorrent
time mktorrent -p
Duration: 0.14s user 0.06s system 96% cpu 0.201 total

# mkbrr
time mkbrr create -p
Duration: 0.13s user 0.05s system 94% cpu 0.189 total

License

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

See LICENSE for the full license text.