name: nix description: Develop with Nix including packages, flakes, NixOS, and derivations. Activate when working with .nix files, flake.nix, flake.lock, or user mentions Nix, nixpkgs, NixOS, derivations, flakes, nix-shell, nix develop, home-manager, or packaging.

Nix Development

Research-first Nix development using parallel DeepWiki queries for accurate, up-to-date information.

Workflow

1. IDENTIFY  → Match question to relevant repos
2. QUERY     → Launch parallel subagents to query DeepWiki
3. SYNTHESIZE → Combine results into actionable guidance

Repo Routing

Language & Concepts

Topic	Repos to Query
Nix language, builtins, syntax	`NixOS/nix.dev`
Attribute sets, functions, let bindings	`NixOS/nix.dev`
Lazy evaluation, recursion	`NixOS/nix.dev`
Derivations (concept)	`NixOS/nix.dev`
Nix store, paths, hashes	`NixOS/nix.dev`
String interpolation, multiline strings	`NixOS/nix.dev`
Path handling, ./. vs toString	`NixOS/nix.dev`
Import, imports, IFD	`NixOS/nix.dev`
lib functions (mkIf, mkOption, etc.)	`NixOS/nixpkgs`, `NixOS/nix.dev`
Nix REPL, nix eval	`NixOS/nix.dev`

Packaging

Topic	Repos to Query
stdenv, mkDerivation	`NixOS/nixpkgs`
Build phases (configure, build, install, check)	`NixOS/nixpkgs`
Fetchers (fetchFromGitHub, fetchurl, fetchgit)	`NixOS/nixpkgs`
Dependencies (buildInputs, nativeBuildInputs, propagatedBuildInputs)	`NixOS/nixpkgs`
Patches, substituteInPlace, patchShebangs	`NixOS/nixpkgs`
Wrappers (makeWrapper, wrapProgram, symlinkJoin)	`NixOS/nixpkgs`
Meta attributes, licenses, maintainers	`NixOS/nixpkgs`
Creating packages from URLs	`nix-community/nix-init`, `NixOS/nixpkgs`
Cross-compilation, pkgsCross	`NixOS/nixpkgs`
Static builds, pkgsStatic, pkgsMusl	`NixOS/nixpkgs`
Trivial builders (writeShellScript, writeText, runCommand)	`NixOS/nixpkgs`
Passthru attributes, tests	`NixOS/nixpkgs`

Language-Specific Builders

Topic	Repos to Query
Rust (buildRustPackage, cargoHash)	`NixOS/nixpkgs`
Go (buildGoModule, vendorHash)	`NixOS/nixpkgs`
Python (buildPythonPackage, buildPythonApplication)	`NixOS/nixpkgs`
Node.js (buildNpmPackage, node2nix)	`NixOS/nixpkgs`
Haskell (haskellPackages, cabal2nix)	`NixOS/nixpkgs`
Java, Maven, Gradle	`NixOS/nixpkgs`
C/C++ (cmake, meson, autotools)	`NixOS/nixpkgs`

Flakes

Topic	Repos to Query
Flake basics, inputs, outputs	`NixOS/nix.dev`
Flake templates, init	`NixOS/nix.dev`
Flake modules, composition	`hercules-ci/flake-parts`
perSystem, multi-platform	`hercules-ci/flake-parts`
Flake overlays	`hercules-ci/flake-parts`, `NixOS/nix.dev`
Flake checks, nix flake check	`NixOS/nix.dev`, `hercules-ci/flake-parts`
Flake apps, nix run	`NixOS/nix.dev`
Flake lock, updating inputs	`NixOS/nix.dev`
follows, input overrides	`NixOS/nix.dev`
Flake-compat (legacy support)	`NixOS/nix.dev`

Development

Topic	Repos to Query
Development shells (mkShell, devShells)	`NixOS/nixpkgs`, `NixOS/nix.dev`
nix develop, nix-shell	`NixOS/nix.dev`
direnv integration	`NixOS/nix.dev`
Environment variables	`NixOS/nixpkgs`

Overrides & Customization

Topic	Repos to Query
override, overrideAttrs	`NixOS/nixpkgs`
Overlays	`NixOS/nixpkgs`, `NixOS/nix.dev`
packageOverrides	`NixOS/nixpkgs`
Fixed-point evaluation	`NixOS/nix.dev`

NixOS & System Config

Topic	Repos to Query
NixOS modules, options	`NixOS/nix.dev`
NixOS configuration	`NixOS/nix.dev`
systemd services	`NixOS/nix.dev`
Users, groups, permissions	`NixOS/nix.dev`
Networking, firewall	`NixOS/nix.dev`
Boot, GRUB, systemd-boot	`NixOS/nix.dev`
Filesystems, partitions	`NixOS/nix.dev`

Home Manager

Topic	Repos to Query
Home-manager basics, installation	`nix-community/home-manager`
User environment, dotfiles	`nix-community/home-manager`
Home-manager modules, options	`nix-community/home-manager`
Programs configuration (git, vim, etc.)	`nix-community/home-manager`
Home-manager + NixOS	`nix-community/home-manager`, `NixOS/nix.dev`
Home-manager + nix-darwin	`nix-community/home-manager`, `nix-darwin/nix-darwin`
Home-manager standalone	`nix-community/home-manager`

macOS (nix-darwin)

Topic	Repos to Query
nix-darwin basics, installation	`nix-darwin/nix-darwin`
macOS system configuration	`nix-darwin/nix-darwin`
Darwin modules, options	`nix-darwin/nix-darwin`
Homebrew integration	`nix-darwin/nix-darwin`
macOS services, launchd	`nix-darwin/nix-darwin`
Darwin + home-manager	`nix-darwin/nix-darwin`, `NixOS/nix.dev`

Contributing & Tooling

Topic	Repos to Query
Updating package versions/hashes	`Mic92/nix-update`
Testing nixpkgs changes	`Mic92/nixpkgs-review`
nixpkgs contribution workflow	`Mic92/nix-update`, `Mic92/nixpkgs-review`
pkgs/by-name structure	`NixOS/nixpkgs`

Testing & CI

Topic	Repos to Query
NixOS tests, nixosTest	`NixOS/nixpkgs`, `NixOS/nix.dev`
VM tests, runNixOSTest	`NixOS/nixpkgs`
Package tests, passthru.tests	`NixOS/nixpkgs`
Hydra CI	`NixOS/nix.dev`
GitHub Actions with Nix	`NixOS/nix.dev`

Containers & Images

Topic	Repos to Query
Docker images, dockerTools	`NixOS/nixpkgs`
OCI images, buildImage	`NixOS/nixpkgs`
Minimal Docker images, streamLayeredImage	`NixOS/nixpkgs`
VM images, disk images	`NixOS/nixpkgs`
ISO images	`NixOS/nixpkgs`

Debugging & Maintenance

Topic	Repos to Query
Build failures, debugging	`NixOS/nixpkgs`, `NixOS/nix.dev`
Garbage collection, nix-collect-garbage	`NixOS/nix.dev`
Binary caches, substituters, Cachix	`NixOS/nix.dev`
Nix profiles, generations	`NixOS/nix.dev`
Nix daemon, nix.conf	`NixOS/nix.dev`
Sandboxing, pure evaluation	`NixOS/nix.dev`
Reproducibility, content-addressing	`NixOS/nix.dev`

Query multiple repos when topics overlap.

Parallel DeepWiki Queries

Launch subagents to query relevant repos simultaneously:

// Single message with multiple parallel Task calls:
Task(
  subagent_type="Explore",
  model="haiku",
  prompt="Use mcp__deepwiki__ask_question to query repo 'NixOS/nixpkgs' with question: '<USER_QUESTION>'. Return the key findings."
)

Task(
  subagent_type="Explore",
  model="haiku",
  prompt="Use mcp__deepwiki__ask_question to query repo 'NixOS/nix.dev' with question: '<USER_QUESTION>'. Return the key findings."
)

Example Query Patterns

"How do I package a Rust CLI tool?"

→ Query NixOS/nixpkgs: "How does buildRustPackage work? What attributes are required?"
→ Query nix-community/nix-init: "How to generate a Rust package derivation from a GitHub URL?"

"How do I create a flake with multiple systems?"

→ Query NixOS/nix.dev: "How do flakes handle multiple systems?"
→ Query hercules-ci/flake-parts: "How to use perSystem for multi-platform flakes?"

"How do I update a package in nixpkgs?"

→ Query Mic92/nix-update: "How to use nix-update to bump package versions?"
→ Query Mic92/nixpkgs-review: "How to test package changes with nixpkgs-review?"

"How do I override a package?"

→ Query NixOS/nixpkgs: "How do override and overrideAttrs work?"
→ Query NixOS/nix.dev: "What are overlays and how to use them?"

DeepWiki Repos

Repo	Best For
`NixOS/nix.dev`	Nix language, tutorials, flake basics, NixOS
`NixOS/nixpkgs`	Package builders, stdenv, overrides, packaging patterns
`nix-community/nix-init`	Auto-generating derivations from URLs
`nix-community/home-manager`	User environment, dotfiles, program configs
`Mic92/nix-update`	Bumping versions and updating hashes
`Mic92/nixpkgs-review`	Testing PRs and local changes
`hercules-ci/flake-parts`	Modular flake configuration, perSystem
`nix-darwin/nix-darwin`	macOS system configuration, Darwin modules, launchd

nix

$ Installer