flake-parts

name	flake-parts
description	Use this skill when the user needs to understand or modify the flake module system that orchestrates the entire configuration — `mkFlake`, `perSystem`, flake modules. Applies when discussing how modules plug together, system-scoped config, or the flake framework itself.
metadata	{"input_rev":"f7c1a2d347e4c52d5fb8d10cb4d94b5884e546fb","input_hash":"sha256-m1Yf0wZ8j1OHjTc2UwHwyQRSnNeSgLJOd7q5Y45hzi4=","when_to_use":"flake-parts, mkFlake, flake modules, perSystem, flake framework"}

Pin check

grep -A4 '"flake-parts"' flake.lock | grep narHash Expected: sha256-m1Yf0wZ8j1OHjTc2UwHwyQRSnNeSgLJOd7q5Y45hzi4= If different, update metadata.input_hash and metadata.input_rev.

Action

1. Call inputs.flake-parts.lib.mkFlake { inherit inputs; } with the module list in flake.nix:111.
2. Define modules using perSystem for system-scoped config (packages, dev shells, checks, formatters), systems for supported architectures, debug for conditional builds.
3. Register host closures via flake.nixosConfigurations, home-manager configs via flake.homeConfigurations.
4. The foundational module at modules/flake-parts.nix:5 imports inputs.flake-parts.flakeModules.modules and re-exports flakeModules from disko and home-manager.

Gotchas

• Every .nix file under modules/ is auto-imported by import-tree and fed to mkFlake. A raw Nix expression (not a flake-parts module function) will break the entire flake.
• perSystem config is scoped to the systems list — if a host uses aarch64-linux but systems omits it, that host's packages won't build.

Verification

nix flake show --json 2>/dev/null | jq '.nixosConfigurations | keys'