Agent Skills Nix

A Nix-based system for fetching, selecting, and installing agent skills.

Skills are installed as symlinks to the Nix store — read-only and automatically updated on rebuild.

Usage

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    agent-skills-nix.url = "github:YOUR_USER/agent-skills-nix";
    
    anthropic-skills = {
      url = "github:anthropics/skills";
      flake = false;
    };
  };

  outputs = { nixpkgs, agent-skills-nix, anthropic-skills, ... }:
    let
      pkgs = nixpkgs.legacyPackages.x86_64-linux;
      lib = agent-skills-nix.lib.${pkgs.system};
      
      skills = {
        "frontend-design" = {
          source = anthropic-skills;
          description = "Frontend design skill";
          enable = true;
        };
        
        "my-skill" = {
          source = ./.;
          path = "skills/my";
          description = "My custom skill";
          enable = false;
        };
      };
    in
    {
      packages.x86_64-linux.default = lib.buildSkillBundle { inherit skills; };
    };
}

nix run    # Build skill bundle

API

lib.buildSkillBundle

buildSkillBundle :: {
  skills :: AttrSet  # { name = { source, path?, description, enable?, ... }; ... }
} -> Derivation

Parameters:

Parameter	Type	Description
skills	AttrSet	Skills to include. See below.
path	String?	Optional explicit path within source. Auto-detected if omitted.

Skill options:

Option	Type	Default	Description
source	Path	—	Flake input or path containing the skill (required)
path	String?	null	Relative path within source to the skill directory
description	String	""	Skill description
enable	Bool	true	Whether to include this skill
version	String	"1.0.0"	Skill version

Skill discovery:

1. If path is set: uses source/<path>
2. Otherwise: searches source/<name>, then recursively searches source/**/<name>

Output:

$out/share/agent-skills/<name>/

Home Manager

{
  imports = [ agent-skills-nix.homeManagerModules.default ];
  
  programs.agent-skills = {
    enable = true;
    skills = {
      "frontend-design" = {
        source = anthropic-skills;
        description = "Frontend design skill";
      };
    };
  };
}

This creates a symlink at ~/.agents/skills → /nix/store/...-agent-skills/share/agent-skills/.

Example

See example/flake.nix for a complete working example.