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Verify whether a NixOS option, Home Manager option, nixpkgs package, module, or attr path actually exists. Use local nix commands and ripgrep instead of guessing.
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Reusable NixOS, Home Manager, and flake configuration patterns. Use when planner or implementer needs proven directory structures, module split patterns, host layouts, secrets organization, overlays, or template-style examples instead of abstract explanation.
Use this skill when the user asks for Nix, Nixpkgs, or NixOS knowledge from local documentation mirrors in this workspace. Start with the high-priority flakes-book branch for practical NixOS and Flakes workflows, then fall back to the official manuals, the NixOS options/module corpus, and the small supplemental wiki navigation branch.
NixOS and Nix flake development for multi-repo architectures, airgapped deployments, and K3s infrastructure. Use when working with flake.nix files, NixOS modules, derivations, devShells, overlays, OCI image packaging, or composing multiple flake repositories. Covers Nix language syntax, flake inputs/outputs, nixosModules exports, stdenv.mkDerivation, and home-manager integration.
Minimal tmux runner for one task per session. Use when Codex needs to create an isolated tmux session, send commands into that session's main shell, inspect the session status, or inspect recent output from the main window.
Use when adding, removing, renaming, reorganizing, or documenting large skill knowledge bases or template libraries in this repository, especially nixos-knowledge-base and nixos-patterns.
| name | nixpkgs-inspector |
| description | Verify whether a NixOS option, Home Manager option, nixpkgs package, module, or attr path actually exists. Use local nix commands and ripgrep instead of guessing. |
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`-- SKILL.md
Use this skill when existence matters.
nix plus local rg.nixpkgs package lookup, NixOS option lookup, and Home Manager option lookup.Nixpkgs:
NIXPKGS_ROOT="$(nix eval --raw nixpkgs#path)"
Home Manager:
HM_ROOT="$(nix flake metadata --json github:nix-community/home-manager/release-25.11 | jq -r .path)"
If the current repo already pins home-manager, prefer its flake first:
nix flake metadata --json /path/to/flake
Package lookup in nixpkgs:
rg -n "<name>" "$NIXPKGS_ROOT/pkgs"
NixOS option lookup:
rg -n "services\\.<name>|programs\\.<name>" "$NIXPKGS_ROOT/nixos/modules"
Home Manager option lookup for package/program trees such as programs.git.*, programs.zsh.*, or services.gpg-agent.*:
rg -n "options\\.<path>|config\\.<path>" "$HM_ROOT/modules"
Examples:
rg -n "options\\.programs\\.git|config\\.programs\\.git" "$HM_ROOT/modules"
rg -n "options\\.programs\\.zsh|config\\.programs\\.zsh" "$HM_ROOT/modules"
If the user names a program first, search that exact tree first. For example, for "can Home Manager configure git?", start with programs.git, not programs.home-manager.
Use this when the question is "which module defines this option tree?"
NixOS:
rg -n "options\\.<path>|config\\.<path>" "$NIXPKGS_ROOT/nixos/modules"
Home Manager:
rg -n "options\\.<path>|config\\.<path>" "$HM_ROOT/modules"
Separate these cases clearly:
Preferred output shape:
Example:
programs.git.enablenix eval --raw nixpkgs#path gives a local nixpkgs source tree.nix flake metadata --json ... exposes the flake source path via .path.nix eval for extra confirmation only when rg is not enough.