# Nix Devshells

> Nix + direnv

- Skill: `comeonoliver/nix-devshells` (Agent Skill)
- Install (CLI): `npx skillmds@latest add comeonoliver/nix-devshells`
- Raw SKILL.md: https://api.skillmd.com/api/skills/comeonoliver/nix-devshells/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: ComeOnOliver (https://skillmd.com/u/comeonoliver)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/comeonoliver/nix-devshells

---

# Nix + direnv

## .envrc
```bash
use flake
```

## flake.nix
```nix
{
  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system: let
      pkgs = nixpkgs.legacyPackages.${system};
    in {
      devShells.default = pkgs.mkShell {
        packages = with pkgs; [ nodejs_20 pnpm python311 postgresql_16 redis ];
        env.DATABASE_URL = "postgresql://localhost/myapp";
      };
    });
}
```

## cd into directory → environment auto-activates
## Everyone on team gets exact same tools
## direnv allow once, then automatic