nixy - Simple Declarative Nix Package Management

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Why nixy?

I was frustrated with asdf and Homebrew while working, and tried to learn Nix several times—but the steep learning curve made me give up every time. What I really wanted was a simple asdf/Homebrew alternative that uses Nix's massive package repository and reproducibility under the hood.

So I built nixy—a simple Rust wrapper with profile support. It runs smoothly and I love it.

Reproducible Nix packages, simple commands. Install packages with a single command, sync them across all your machines.

nixy install ripgrep    # That's it. Nix made simple.

nixy manages your Nix packages through a declarative nixy.json configuration file, ensuring the same packages and versions on every machine.

Prerequisites

nixy requires Nix. Install with:

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install

Quick Start

1. Install nixy

# Quick install (recommended)
curl -fsSL https://raw.githubusercontent.com/yusukeshib/nixy/main/install.sh | bash

# Or with cargo
cargo install nixy-rs

# Or with nix
nix profile install github:yusukeshib/nixy

2. Set up your shell

Add to .bashrc, .zshrc, etc.:

eval "$(nixy config zsh)"

For fish (~/.config/fish/config.fish):

nixy config fish | source

3. Start using

nixy install ripgrep        # Install latest version
nixy install nodejs@20      # Install specific major version
nixy install [email protected]  # Install exact version
nixy list                   # See installed packages with versions
nixy search python          # Find packages + available versions
nixy uninstall nodejs       # Remove a package
nixy upgrade                # Upgrade all within version constraints
nixy upgrade nodejs         # Upgrade specific package

Commands

Version Specification

nixy supports flexible version constraints via Nixhub:

nixy install nodejs           # Latest version
nixy install nodejs@20        # Latest 20.x.x (semver range)
nixy install [email protected]     # Latest 20.11.x
nixy install [email protected]   # Exact version

When you run nixy upgrade nodejs, it respects your version constraint:

• nodejs (no version) → upgrades to absolute latest
• nodejs@20 → upgrades to latest 20.x.x

Platform-Specific Installation

Install packages only for specific platforms:

nixy install terminal-notifier --platform darwin   # macOS only
nixy install linux-tool --platform linux           # Linux only
nixy install specific --platform aarch64-darwin    # Apple Silicon only

Valid platform names:

• darwin or macos → both x86_64-darwin and aarch64-darwin
• linux → both x86_64-linux and aarch64-linux
• Full names: x86_64-darwin, aarch64-darwin, x86_64-linux, aarch64-linux

Platform-specific packages are shown with their restriction in nixy list:

terminal-notifier@2.0.0  (nixpkgs) [darwin]

Profiles

Maintain separate package sets for different contexts:

nixy profile work -c            # Create and switch to new profile
nixy install slack terraform    # Install work packages

nixy profile personal -c        # Another profile
nixy install spotify            # Different packages

nixy profile                    # Interactive profile selector
nixy profile work               # Switch to existing profile
nixy profile old -d             # Delete a profile (with confirmation)

All profiles are stored in ~/.config/nixy/nixy.json, with generated flakes in ~/.local/state/nixy/profiles/<name>/.

How nixy works

nixy is purely declarative - nixy.json is the source of truth, and flake.nix is regenerated from it on every operation.

┌─────────────────┐      ┌─────────────┐      ┌─────────────────────────────┐
│   nixy.json     │ ──── │  flake.nix  │ ──── │ ~/.local/state/nixy/env/bin │
│ (source of truth)│ generate │ (+ flake.lock)│ nix build │      (symlink to /nix/store) │
└─────────────────┘      └─────────────┘      └─────────────────────────────┘
                                                            │
                                                            ▼
                                              eval "$(nixy config zsh)" adds
                                              this path to your $PATH

Unlike nix profile which maintains mutable state, nixy:

1. Regenerates flake.nix from nixy.json on every operation
2. Runs nix build to create a combined environment in /nix/store
3. Creates a symlink at ~/.local/state/nixy/env pointing to that environment
4. Your shell config just adds ~/.local/state/nixy/env/bin to $PATH

This means syncing is simple: copy nixy.json and your profile's flake.lock (e.g., ~/.local/state/nixy/profiles/<profile>/flake.lock) to another machine, run nixy sync, and you have the exact same environment.

FAQ

How do I find the right package name? Use nixy search <keyword>.

Where are packages installed? In /nix/store/. nixy creates a symlink at ~/.local/state/nixy/env pointing to your environment.

Can I edit flake.nix manually? No, it's regenerated from nixy.json on every operation. Use flake references for custom packages (e.g., nixy install github:user/repo).

How does nixy differ from nix profile? nixy adds reproducibility on top of Nix - your nixy.json + flake.lock can be synced and version controlled across machines.

Does nixy honor flake-declared binary caches (e.g. Cachix)? Yes. nixy passes --accept-flake-config to every nix invocation, so a custom flake's nixConfig.extra-substituters / extra-trusted-public-keys are honored automatically. This lets nixy install <flake-ref> pull prebuilt artifacts from project-provided caches instead of rebuilding locally.

How do I rollback? Version control your nixy.json and flake.lock with git:

cd ~/.config/nixy
git checkout HEAD~1 -- nixy.json
nixy sync

Advanced

~/.config/nixy/
├── nixy.json        # Source of truth (all profiles)
└── packages/        # Global custom package definitions

~/.local/state/nixy/
├── env              # Symlink to active profile's build
└── profiles/
    ├── default/
    │   ├── flake.nix    # Generated (do not edit)
    │   └── flake.lock   # Nix lockfile
    └── work/
        └── ...

nixy install github:nix-community/neovim-nightly-overlay

nixy install github:nix-community/neovim-nightly-overlay#neovim

nixy install path:./my-flake

{
  inputs.nixy-packages.url = "path:~/.local/state/nixy/profiles/default";

  outputs = { self, nixpkgs, nixy-packages }: {
    # nixy-packages.packages.<system>.default is a buildEnv with all packages
  };
}

License

MIT