muu

A minimal, fast task runner written in Rust.

Features

• TOML-based task definitions
• Local (muu.toml) and global (~/.config/muu/config.toml) configuration
• Interactive task selector with fuzzy filtering
• Positional and named arguments with defaults
• Multi-line commands with fail-fast execution
• Single binary, no runtime dependencies

Install

Shell (macOS / Linux)

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/mfyuu/muu/releases/latest/download/muu-installer.sh | sh

PowerShell (Windows)

powershell -ExecutionPolicy Bypass -c "irm https://github.com/mfyuu/muu/releases/latest/download/muu-installer.ps1 | iex"

Homebrew (macOS)

brew install mfyuu/tap/muu

Quick Start

Create a muu.toml in your project:

muu init

This generates a starter file. Edit it to define your tasks:

[tasks.hello]
cmd = "echo hello"

[tasks.deploy]
description = "Deploy to S3"
cmd = "aws s3 sync $dir s3://$bucket"
args = { dir = ".", bucket = "" }

[tasks.setup]
cmd = """
brew install node
npm install
"""

Usage

Run a task

muu deploy ./dist my-bucket      # positional args
muu deploy --bucket=my-bucket    # named args (dir uses default ".")
muu hello                        # no args

Interactive selector

muu

Launches a fuzzy-searchable task selector. If the selected task has arguments, you'll be prompted for each one.

List tasks

muu list

deploy - Deploy to S3   [local]
hello                   [local]
setup                   [local]

Filter by scope

muu -l         # local tasks only
muu -g         # global tasks only
muu list -l    # works with list too

Task Definition

Field	Type	Required	Description
cmd	string	yes	Command to run. Use """ for multi-line.
description	string	no	Shown in muu list and the selector.
args	inline table	no	Argument definitions. Key order = positional order.

Arguments

args = { dir = ".", bucket = "" }

• Non-empty value = optional (used as default)
• Empty string "" = required (error if not provided)
• "?" = optional with no default (empty string if omitted)
• Key order determines positional argument order

# Optional argument example
[tasks.greet]
cmd = """
if [ -n "$name" ]; then echo "Hello, $name!"; else echo "Hello!"; fi
"""
args = { name = "?" }

muu greet          # Hello!
muu greet Alice    # Hello, Alice!

Shell Completions

Tab completion for task names, subcommands, and flags.

Zsh (add to ~/.zshrc):

source <(COMPLETE=zsh muu)

Bash (add to ~/.bashrc):

source <(COMPLETE=bash muu)

Fish (add to ~/.config/fish/config.fish):

COMPLETE=fish muu | source

Configuration

• Local: searches upward from the current directory for muu.toml
• Global: ~/.config/muu/config.toml
• Local tasks override global tasks with the same name

License

MIT