autoImportExcept

When and how to use autoImport and autoImportExcept outside of the main mkFlake wiring.

---

What they are

autoImport and autoImportExcept are pure builtins utilities exported from the nix-wire flake:

inputs.nix-wire.lib.autoImport         # path -> [path]
inputs.nix-wire.lib.autoImportExcept   # path -> [string] -> [path]

They return a list of paths (not an attrset), designed for use in imports lists. Unlike wireGeneric (used internally by mkFlake), these work in any evaluation context - flakes, modules, nix repl, nix eval.

When to use them

The main mkFlake wiring handles hosts, modules, packages, and overlays automatically. But sometimes you need to auto-import files inside a module or config - for example:

• A NixOS module that imports all its sibling module files
• A directory of service configs that should all be imported
• A user config that imports multiple sub-configs

autoImport

autoImport : path -> [path]

Scans a directory and returns paths to all sibling .nix files and directories with default.nix. Skips default.nix itself.

Example

# modules/nixos/services/default.nix
{ inputs, ... }:
{
  imports = inputs.nix-wire.lib.autoImport ./.;
}

modules/nixos/services/
├── default.nix      # ← this file (skipped)
├── ssh.nix           # ← imported
├── nginx/
│   └── default.nix   # ← imported
└── docker.nix        # ← imported

Result: imports = [ ./ssh.nix ./nginx ./docker.nix ]

autoImportExcept

autoImportExcept : path -> [string] -> [path]

Same as autoImport, but also skips entries matching the exclusions list.

Example: exclude a file

{ inputs, ... }:
{
  imports = inputs.nix-wire.lib.autoImportExcept ./. [ "experimental.nix" ];
}

Example: exclude a directory

{ inputs, ... }:
{
  imports = inputs.nix-wire.lib.autoImportExcept ./. [ "wip" ];
  # If wip/default.nix exists, the wip directory is skipped
}

Example: exclude multiple entries

{ inputs, ... }:
{
  imports = inputs.nix-wire.lib.autoImportExcept ./. [
    "experimental.nix"
    "wip"
    "disabled.nix"
  ];
}

---

Difference from wireGeneric

Feature	autoImport / autoImportExcept	wireGeneric (internal)
Returns	List of paths	Attrset { name = value; }
Precedence rule	No - both foo.nix and foo/ included	Yes - foo/default.nix wins over foo.nix
Context	Any (pure builtins)	Requires nixpkgs lib
Use case	imports lists in modules	Building flake attributes
Skips default.nix	Yes	Yes

No precedence in autoImport

autoImport does not apply the directory-over-file precedence rule. If both foo.nix and foo/default.nix exist, both are returned in the list. This would cause a duplicate module error. Use autoImportExcept to exclude one:

imports = inputs.nix-wire.lib.autoImportExcept ./. [ "foo.nix" ];
# Now only foo/ (with default.nix) is imported

---

Real-world pattern: auto-importing services

A common pattern is a "services" module that imports all service configs in a directory:

# modules/nixos/services/default.nix
{ inputs, ... }:
{
  imports = inputs.nix-wire.lib.autoImport ./.;
}

Then in your host:

# hosts/nixos/myhost.nix
{ flake, ... }:
{
  imports = [ flake.nixosModules.services ];
}

This way, adding a new service is just dropping a .nix file in the services/ directory - no manual import list to maintain.