# Adding Dev Tools

How to add development tools to the ops-jrz1 server.

## Options

### 1. System-wide (all users)

Best for: common tools everyone needs (git, vim, htop, curl)

```nix
# configuration.nix
environment.systemPackages = with pkgs; [
  tldr
  bat
  fd
];
```

Then deploy:
```bash
nix flake check
nixos-rebuild switch --flake .#ops-jrz1 --target-host root@ops-jrz1
```

### 2. Per-user (nix profile)

Best for: personal preferences (editor configs, shell tools)

```bash
# User runs on server:
nix profile install nixpkgs#tldr
nix profile install nixpkgs#bat

# List installed:
nix profile list

# Update all:
nix profile upgrade '.*'

# Remove:
nix profile remove tldr
```

Survives reboots, user-managed, not in git.

### 3. Per-project (flake devShell)

Best for: project-specific dependencies

```nix
# flake.nix in project directory
{
  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

  outputs = { nixpkgs, ... }:
  let
    pkgs = nixpkgs.legacyPackages.x86_64-linux;
  in {
    devShells.x86_64-linux.default = pkgs.mkShell {
      packages = with pkgs; [
        python3
        uv
        ruff
      ];
    };
  };
}
```

Then:
```bash
nix develop        # Enter shell
# or with direnv:
echo "use flake" > .envrc
direnv allow
```

### 4. External flake (not in nixpkgs)

For tools packaged as flakes (like opencode, beads):

```nix
# flake.nix inputs
inputs.sometool.url = "github:org/sometool";

# Pass to NixOS
specialArgs = {
  sometool = inputs.sometool.packages.x86_64-linux.default;
};

# configuration.nix
environment.systemPackages = [ sometool ];
```

## Finding Packages

```bash
# Search nixpkgs
nix search nixpkgs tldr

# Check if package exists
nix eval nixpkgs#tldr.meta.description
```

## Recommendations

| Tool Type | Method |
|-----------|--------|
| Core utils (git, curl, vim) | System-wide |
| Build tools (go, rust, node) | System-wide |
| Personal prefs (tldr, bat, eza) | Per-user |
| Project deps (linters, formatters) | Per-project |
| AI tools with auth (claude, gemini) | Per-user |

## Updating

```bash
# Update flake inputs (external tools)
nix flake update
nixos-rebuild switch ...

# Update user profile
nix profile upgrade '.*'
```