# Nh

> Switch NixOS/Home Manager configs with nh — cleaner interface for builds, switches, and garbage collection. Use when running os/home switch or pruning old generations.

- Skill: `knoopx/nh` (Agent Skill)
- Install (CLI): `npx skillmds@latest add knoopx/nh`
- Raw SKILL.md: https://api.skillmd.com/api/skills/knoopx/nh/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: knoopx (https://skillmd.com/u/knoopx)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/knoopx/nh

---


# nh (Nix Helper)

Cleaner interface for Nix operations — builds, switches, and garbage collection with readable output.

## Switching Configuration

Build and activate a configuration:

```bash
nh os switch path:.           # NixOS — build and activate
nh os test path:.             # Build and test (rollback after timeout)
nh os build path:.            # Build only, don't activate
nh os boot path:.             # Make it the boot default without activating
```

Home Manager:

```bash
nh home switch path:.         # Build and activate Home Manager config
nh home build path:.          # Build only
```

macOS with nix-darwin:

```bash
nh darwin switch path:.       # Build and activate darwin config
```

Path inference works — `nh os switch` uses the local `flake.nix` in the current directory. Prefix remote paths with `path:` to include untracked files.

## Maintenance & Cleanup

Clean the Nix store and old generations:

```bash
nh clean all --keep-since 7d  # Remove profiles older than 7 days
nh clean user --keep 5        # Keep last 5 user profiles
nh clean all                  # Full garbage collection
```

## Searching & Updating

Search available packages:

```bash
nh search ripgrep             # Search by name or description
```

Update flake inputs before building:

```bash
nh os switch --update path:.  # Update inputs, then build and switch
```

## Common Options

- `--dry` — show what would happen without making changes
- `--ask` — ask for confirmation (avoid in headless/automated scripts)