mise

mise - Tool Version Manager

mise (formerly rtx) is a polyglot tool version manager. It manages runtime versions for languages and tools (node, python, ruby, go, rust, etc.) using a single mise.toml configuration file per project.

Quick Reference

Installation

# Install via curl (recommended for CI/web sessions)
curl https://mise.run | sh

# Install via Homebrew (macOS/Linux)
brew install mise

# Install via GitHub releases (direct binary)
MISE_VERSION="2024.12.16"
curl -fsSL "https://github.com/jdx/mise/releases/download/v${MISE_VERSION}/mise-v${MISE_VERSION}-linux-x64" -o mise
chmod +x mise

Shell Activation

# bash
eval "$(mise activate bash)"

# zsh
eval "$(mise activate zsh)"

# fish
mise activate fish | source

Core Commands

Command	Description
mise install	Install all tools from mise.toml
mise install <tool>@<version>	Install specific tool version
mise use <tool>@<version>	Add tool to mise.toml and install
mise ls	List installed tool versions
mise ls-remote <tool>	List available remote versions
mise trust	Trust the current directory's config
mise self-update	Update mise itself
mise doctor	Check mise health and configuration
mise env	Show environment variables mise would set
mise exec -- <command>	Run command with mise-managed tools

Configuration (mise.toml)

Basic Structure

[tools]
node = "22"           # Major version (auto-resolves to latest 22.x.x)
python = "3.12.1"     # Exact version
bun = "latest"        # Always latest stable
go = "1.22"           # Minor version pin
"npm:prettier" = "latest"  # npm package as tool

[settings]
legacy_version_file = false  # Don't read .node-version, .python-version etc.

[env]
NODE_ENV = "development"
DATABASE_URL = "postgres://localhost/mydb"

Version Specifiers

[tools]
node = "22"          # Fuzzy: latest 22.x
node = "22.11.0"     # Exact version
node = "lts"         # Latest LTS
node = "latest"      # Latest stable
node = "sub-0.1"     # Sub-version prefix

Multiple Versions

[tools]
python = ["3.12", "3.11"]  # Install both, 3.12 is default

Tool Backends

mise supports multiple package ecosystems:

[tools]
# Core tools (built-in support)
node = "22"
python = "3.12"
go = "1.22"
ruby = "3.3"
java = "21"
rust = "1.77"

# npm packages
"npm:prettier" = "latest"
"npm:eslint" = "latest"
"npm:typescript" = "5"

# pip packages
"pipx:black" = "latest"

# cargo packages
"cargo:ripgrep" = "latest"

# go packages
"go:golang.org/x/tools/gopls" = "latest"

# GitHub releases via ubi (Universal Binary Installer)
"ubi:cli/cli" = "latest"           # GitHub CLI
"ubi:casey/just" = "latest"        # just task runner
"ubi:jqlang/jq" = "latest"        # jq JSON processor

# aqua registry
"aqua:cli/cli" = "latest"

Environment Variables

[env]
# Static values
DATABASE_URL = "postgres://localhost/mydb"
NODE_ENV = "development"

# Reference other env vars
HOME_BIN = "{{env.HOME}}/bin"

# File-based env (like dotenv)
_.file = ".env"

# Path manipulation
_.path = ["./bin", "./node_modules/.bin"]

Tasks

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

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

[tasks.install]
run = "npm install"
description = "Install dependencies"

Common Workflows

Setting Up a New Project

# Initialize mise for a project
mise use node@22 python@3.12 bun@latest

# This creates/updates mise.toml with the specified tools
# and installs them immediately

Adding a New Tool

# Add a tool and pin version in mise.toml
mise use go@1.22

# Add npm-based tool
mise use npm:prettier@latest

# Add from GitHub releases
mise use ubi:casey/just@latest

Updating Tools

# Update all tools to latest matching versions
mise upgrade

# Update specific tool
mise upgrade node

# Update mise itself
mise self-update

Listing and Checking

# List all installed versions
mise ls

# List what versions are available for a tool
mise ls-remote node

# Check for outdated tools
mise outdated

# Verify mise configuration health
mise doctor

CI/CD Integration

# In CI, trust and install without prompts
mise trust
mise install -y

# Run a command with mise-managed tools
mise exec -- npm test

# Or activate in the shell
eval "$(mise activate bash)"
npm test

Environment Variable Management

# Show what env vars mise would set
mise env

# Set an env var in mise.toml
mise set NODE_ENV=production

# Unset an env var
mise unset NODE_ENV

Plugin Settings

This plugin supports configuration via plugins.settings.yaml:

mise:
  enabled: true
  installToProject: true # Install to $project/bin/.local
  backgroundInstall: false # Install in background
  version: "latest" # Specific version or "latest"
  autoInstallTools: true # Run mise install after setup
  autoTrust: true # Auto-trust project mise.toml

Place in:

• $CLAUDE_PROJECT_DIR/.claude/plugins.settings.yaml (project-level)
• ~/.claude/plugins.settings.yaml (user-level)

Troubleshooting

"command not found" after install

Ensure mise is activated in your shell. Run eval "$(mise activate bash)".

Tools not installing

1. Check mise doctor for configuration issues
2. Ensure mise.toml is trusted: mise trust
3. Check network connectivity for downloads

Version conflicts with system tools

mise shims take precedence when activated. Use mise which <tool> to verify which version is being used.

Web session specifics

In Claude Code web sessions, mise is auto-installed by this plugin to $CLAUDE_PROJECT_DIR/bin/.local/mise. The PATH is updated via CLAUDE_ENV_FILE. If tools aren't available, check that the session start hook completed.