---
comment: true
title: Meta Options
description: wire hive meta options.
---

# Meta Options

{{ $frontmatter.description }}

## meta.nixpkgs

Tells wire how to get `nixpkgs`.

_Type:_ A path or an instance of `nixpkgs`.

_Default:_ `null`

_Examples:_

```nix
{
  # all valid options

  meta.nixpkgs = <nixpkgs>;

  meta.nixpkgs = import <nixpkgs> { };

  meta.nixpkgs = import sources.nixpkgs { };

  meta.nixpkgs = inputs.nixpkgs.outPath;

  meta.nixpkgs = inputs.other-nixpkgs.outPath;
}
```

## meta.specialArgs

Extra `specialArgs` to pass to each node & `default`.

::: tip

wire always passes `name` (name of the node)
and `nodes` (attribute set of all nodes) as args, even if `meta.specialArgs =
{ }`.

:::

_Type:_ attribute set

_Default:_ `{ }`

_Example:_

```nix
{
  meta.specialArgs = {
    # pass flake inputs as specialArgs
    inherit inputs;
  };
}
```

## meta.nodeSpecialArgs

Extra `specialArgs` to override `meta.specialArgs` for each node

_Type:_ attribute set of attribute set

_Default:_ `{ }`

_Example:_

```nix
{
  meta.nodeSpecialArgs = {
    extra-property = "some-value";
  };
}
```

## meta.nodeNixpkgs

Per-node nixpkgs to override `meta.nixpkgs`.

See `meta.nixpkgs` examples for possible values.

_Type:_ attribute set of path or an instance of `nixpkgs`

_Default:_ `{ }`

_Example:_

```nix
{
  meta = {
    nixpkgs = import <nixpkgs> { };

    nodeNixpkgs = {
      node-b = import <special-nixpkgs> { };
    };
  };

  node-a =
    { pkgs, ... }:
    {
      # uses <nixpkgs> (meta.nixpkgs)
    };

  node-b =
    { pkgs, ... }:
    {
      # uses <special-nixpkgs> (meta.nodeNixpkgs.node-b)
    };
}
```