mica

A TUI for managing Nix environments. Mica lets you search packages, apply presets, and keep a reproducible default.nix with minimal Nix ceremony.

Features

• Interactive TUI for package search and preset selection
• Generates a managed default.nix and preserves edits outside # mica: markers
• Pin management for nixpkgs
• Bundled presets plus user presets from configurable directories
• Cached SQLite index for fast search

Requirements

• Nix installed, with nix-env and nix-prefetch-url available
• Optional: Rust toolchain for development from source
• Optional: direnv for project shells

Install

nix-env -f https://github.com/jpetrucciani/nix/archive/main.tar.gz -iA mica

Quick Start (Project Mode)

1. In a project directory without an existing managed default.nix, run mica init
2. Launch the TUI with mica tui
3. In the TUI, search packages, toggle selections, and press Ctrl+S to save

Targeting Examples (--file, --global)

• mica --file ./default.nix list inspect a specific managed file
• mica --file ./default.nix diff check drift for that file
• mica --global list inspect your global profile state
• mica --global add ripgrep add a package globally
• mica --global generations list inspect global generations

TUI Keys

• Tab switch focus between packages, presets, and changes
• Type search in the focused panel, Ctrl+U clears search
• Search shortcuts: 'exact, bin:, name:, desc: (for example bin:rg or 'name:ripgrep)
• Enter or Space toggle selection
• S cycle search mode (all, name, desc, bin)
• Ctrl+P package info, Ctrl+V version picker
• B/I/V toggle broken, insecure, and installed-only filters
• L/O edit license and platform filters
• E edit environment variables
• H edit shell hook
• T toggle presets panel, C toggle changes panel
• D diff preview, and inside diff view T toggles full vs changes-only
• K toggle details panel
• U update nixpkgs pin
• R rebuild index, Y reload from nix
• Ctrl+S save, Ctrl+Q quit, ? help

CLI Examples

• mica init initialize a project default.nix
• mica tui launch the TUI
• mica add ripgrep fd add packages
• mica remove fd remove packages
• mica search rg --mode binary search by binary name
• mica apply rust apply a preset
• mica unapply rust remove a preset
• mica --file ./default.nix list target a specific file
• mica --global list target global profile state
• mica diff show drift between state and default.nix
• mica sync regenerate default.nix from state
• mica index rebuild /tmp/nixpkgs.json
• mica index rebuild-local ~/dev/jpetrucciani-nix --skip-attr home-manager --show-trace

Configuration Config lives at ~/.config/mica/config.toml.

[nixpkgs]
default_url = "https://github.com/jpetrucciani/nix"
default_branch = "main"

[presets]
extra_dirs = ["~/my-presets"]

[index]
remote_url = "https://static.g7c.us/mica"
update_check_interval = 24

[tui]
show_details = true

For index.remote_url, mica tries <remote>/<nixpkgs_commit>.db.

You can also override the repo for mica init with --repo or MICA_NIXPKGS_REPO.

Files and State

• Project state is embedded in default.nix
• Global profile state uses ~/.config/mica/profile.toml and ~/.config/mica/profile.nix
• Package index cache is stored at ~/.config/mica/cache/index.db

Presets Mica ships with bundled presets in presets/ and can load extra preset directories via presets.extra_dirs.

Advanced

• Extra pin workflows are available via mica pin --help.

Development

• direnv exec . cargo run -p mica -- tui
• direnv exec . cargo fmt
• direnv exec . cargo clippy --all --benches --tests --examples --all-features -- -D warnings -W clippy::collapsible_else_if

Docs (VitePress + bun)

• bun install
• bun run docs:dev
• bun run docs:build