mise: Modern Dev Tools Version Manager

Most developers manage multiple version managers: nvm for Node.js, pyenv for Python, rbenv for Ruby, goenv for Go. Each has separate config files, hooks, and commands. mise (pronounced "meeze", previously rtx) replaces all of them. It's a single Rust-based tool that installs and manages runtime versions for any language, reads .tool-versions files for project consistency, and runs 3-10x faster than asdf (which it's API-compatible with).

Photo by Harshit Katiyar on Unsplash

Why mise

Single tool for all runtimes: Install Node 20, Python 3.12, Ruby 3.3, and Go 1.22 with one tool and one config file.

Speed: Written in Rust. Activating mise adds ~2ms to shell startup vs 50-100ms for asdf. Installing tools is parallelized.

asdf compatibility: mise reads .tool-versions files (asdf's format). Switch from asdf to mise with no project file changes.

Project-scoped versions: Put a .mise.toml or .tool-versions in your project directory — anyone who clones the repo gets the same tool versions.

Task runner: mise includes a task runner that reads from .mise.toml, eliminating the need for Makefiles for simple project tasks.

Installation

# macOS (Homebrew)
brew install mise

# Linux/macOS (curl installer)
curl https://mise.run | sh

# Cargo
cargo install mise

Add to shell profile:

# bash
echo 'eval "$(mise activate bash)"' >> ~/.bashrc

# zsh
echo 'eval "$(mise activate zsh)"' >> ~/.zshrc

# fish
echo 'mise activate fish | source' >> ~/.config/fish/config.fish

Basic Usage

# Install a specific version
mise install node@20
mise install node@lts
mise install [email protected]
mise install [email protected]
mise install [email protected]

# Set global defaults
mise use --global node@20
mise use --global [email protected]

# Set project-scoped versions (writes to .mise.toml)
cd my-project
mise use node@18
mise use [email protected]

# Check current versions
mise current

# List installed versions
mise list

# Update all tools
mise upgrade

.mise.toml — Project Configuration

mise uses .mise.toml for project configuration:

# .mise.toml
[tools]
node = "20"
python = "3.12"
ruby = "3.3"
go = "1.22"

# Install a specific minor version
terraform = "1.7.0"

# Multiple versions (primary + alternates)
node = ["20", "18"]

[env]
# Environment variables when in this project
DATABASE_URL = "postgres://localhost/myapp_dev"
NODE_ENV = "development"

[tasks.test]
description = "Run tests"
run = "npm test"

[tasks.build]
description = "Build the project"
run = "npm run build"

[tasks.dev]
description = "Start dev server"
run = "npm run dev"

.tool-versions Compatibility

If you're coming from asdf:

# .tool-versions (asdf format — mise reads this too)
nodejs 20.10.0
python 3.12.0
ruby 3.3.0

mise reads both .mise.toml and .tool-versions — no migration required.

Installing Tools (Plugins)

mise uses the same plugin ecosystem as asdf. Most tools are available by default:

# List available tools
mise plugins ls-remote

# Install from the registry
mise install [email protected]
mise install [email protected]
mise install [email protected]
mise install awscli@2
mise install rust@stable

# Install a tool using a URL-based plugin
mise plugin install my-tool https://github.com/org/asdf-my-tool

Task Runner

mise includes a built-in task runner:

# .mise.toml
[tasks.test]
description = "Run the test suite"
run = "pytest tests/ -v"
depends = ["install"]

[tasks.install]
description = "Install dependencies"
run = "pip install -r requirements.txt"

[tasks.lint]
description = "Run linters"
run = [
  "flake8 src/",
  "mypy src/",
]

[tasks.ci]
description = "Full CI pipeline"
depends = ["install", "lint", "test"]

mise run test
mise run lint
mise run ci
mise tasks  # List all tasks

Shell Integration

mise automatically activates the correct versions when you cd into a project:

cd ~/projects/new-app       # Uses .mise.toml: node@20
cd ~/projects/legacy-app    # Uses .tool-versions: node@14

No manual nvm use or pyenv local needed. mise hooks into your shell's cd command.

Environment Variables

mise can manage per-project environment variables:

[env]
DATABASE_URL = "postgres://localhost/dev"
SECRET_KEY = "dev-secret-key"

Or reference external files (with .mise.toml in .gitignore):

[env]
_.file = ".env"

This replaces direnv for many use cases.

Migration from nvm / pyenv / asdf

From nvm:

# Install mise
curl https://mise.run | sh
# Add to shell profile
echo 'eval "$(mise activate zsh)"' >> ~/.zshrc

# Set global node version
mise use --global node@20

# Remove nvm from shell profile
# Remove ~/.nvm and nvm shell hooks

From asdf: Nothing to change — mise reads your .tool-versions files.

mise vs asdf

mise vs nvm

nvm is Node.js specific. mise handles Node, Python, Ruby, Go, and 300+ other tools. If you only use Node, nvm works. For polyglot development, mise handles everything.

Shell Prompt Integration

Show active tool versions in your prompt (works with Starship):

# ~/.config/starship.toml
[mise]
format = "[$symbol$version]($style) "
symbol = "mise "

Or use mise current in your prompt script to show active versions.

mise is a substantial quality-of-life improvement for developers working with multiple runtimes and projects. The asdf compatibility makes migration nearly effortless.