API Guide

lib

This section covers important functions available in Flakelight's lib attribute.

mkFlake

The outputs of a flake using Flakelight are created using the mkFlake function. When called directly, Flakelight invokes mkFlake, as follows:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      # Your flake configuration here
    };
}

To call mkFlake explicitly, you can do:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight.lib.mkFlake ./. {
      # Your flake configuration here
    };
}

mkFlake takes two parameters: the path to the flake's source and a Flakelight module.

If you need access to module args, you can write it as bellow:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. ({ lib, config, ... }: {
      # Your flake configuration here
    });
}

Module arguments

The following module arguments are available:

src: The flake's source directory
lib: nixpkgs lib attribute
config: configured option values
options: available options
flakelight: flakelight lib attribute
inputs: value of inputs option
outputs: resulting output (i.e. final flake attributes)
pkgsFor: attrset mapping systems to the pkgs set for that system
moduleArgs: All of the available arguments (passed to auto-loaded files)

Additional pkgs values

Functions that take the package set as an argument, such as package definitions or perSystem values, have several additional values available in the package set.

The src, flakelight, inputs, outputs, and moduleArgs attributes are the same as the above module arguments.

inputs' and outputs' are transformed versions of inputs and outputs with system preselected. I.e., inputs.emacs-overlay.packages.x86_64-linux.default can be accessed as inputs'.emacs-overlay.packages.default.

defaultMeta is a derivation meta attribute set generated from options. Modules setting packages.default should use this to allow meta attributes to be configured.

Module options

This section covers the options available to modules.

inputs

Type: AttrsOf FlakeInput

The inputs option is an attrset of the flake inputs used by flakelight modules. These inputs get passed as the inputs module argument, and are used for inputs and inputs' in the package set.

Default values are automatically initialized from your flake inputs by reading your flake.lock. Note that this does not include the self argument; for using self, use inherit inputs or otherwise define inputs. The default values also are not affected by nix command flags like --override-input, so inputs should be passed to enable full CLI functionality.

Flakelight will add a recent nixpkgs input if your flake does not have one. Other flakelight modules may provide default inputs for their dependencies.

To use a different nixpkgs from the built-in default (passing all inputs):

{
  inputs = {
    flakelight.url = "github:nix-community/flakelight";
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
  };
  outputs = { flakelight, ... }@inputs:
    flakelight ./. {
      inherit inputs;
    };
}

Or to just pass just the nixpkgs input:

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    flakelight.url = "github:nix-community/flakelight";
  };
  outputs = { flakelight, nixpkgs, ... }:
    flakelight ./. {
      inputs.nixpkgs = nixpkgs;
    };
}

systems

Type: [SystemStr]

The systems option sets which systems per-system outputs should be created for.

If not set, the default is x86_64-linux and aarch64-linux.

To also support i686-linux and armv7l-linux, you would configure systems as follows:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      systems = [ "x86_64-linux" "aarch64-linux" "i686-linux" "armv7l-linux" ];
    };
}

To support all systems supported by flakes, set systems as follows:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. ({ lib, ... }: {
      systems = lib.systems.flakeExposed;
    });
}

To support all Linux systems supported by flakes, set systems as follows:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. ({ lib, ... }: {
      systems = lib.intersectLists
        lib.systems.doubles.linux
        lib.systems.flakeExposed;
    });
}

nixDir

Type: Path | null

The nixDir option is ./nix by default and sets which directory to use to automatically load nix files to configure flake options from.

For a given option, the following is checked in order:

If ${nixDir}/option.nix exists, the value is the file imported.
Else if ${nixDir}/option is a directory with a default.nix, the value is the directory imported.
Else if ${nixDir}/option is a directory, and option accepts an attrset, the value in an attrset with an attr for each importable item in the directory, for which the values are the corresponding items imported. An importable item is a file ending with .nix or a directory containing a default.nix. This is the same as the flakelight importDir function.
Else if ${nixDir}/option is a directory, and option accepts an list, it results in a list, the elements of which are the values of the attrset from the prior branch.

To enable using a directory for an attrset that includes a default attribute, attr names can be escaped with an underscore. For example, ${nixDir}/nix/packages/_default.nix will be loaded as packages.default.

Aliases for options can be set with the nixDirAliases option. For example, by default nixDirAliases.nixosConfigurations = [ "nixos" ]; is set which means "nixos" can be used instead of "nixosConfigurations" for loading the files as described above.

All options except for nixDir and _module can be configured this way.

To apply transformations on the output of an autoloaded directory, you can use option/default.nix and load the directory with flakelight.importDir.

If you add a new config type that should be loaded as paths instead of imported, such as configs for Nix modules, add them to the nixDirPathAttrs option. This is already set for built-in module options. When options whose names are in nixDirPathAttrs are loaded as a directory, flakelight.importDirPaths is used instead of flakelight.importDir.

You may set nixDir to null to not load from any directory.

outputs

Type: AttrSet | (ModuleArgs -> AttrSet)

The outputs option allows you to directly configure flake outputs. This should be used for porting or for configuring output attrs not otherwise supported by Flakelight.

The option value may be an attrset or a function that takes moduleArgs and returns and attrset.

To add a example.test output to your flake you could do the following:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      outputs = {
        example.test = "hello";
      };
    };
}

With the above, nix eval .#example.test will output "hello".

This can be used to configure any output, for example directly setting an overlay (though this can be configured with the overlays option):

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      outputs.overlays.clang = final: prev: { stdenv = final.clangStdenv; };
    };
}

perSystem

Type: Pkgs -> AttrSet

The perSystem option allows you to directly configure per-system flake outputs, and gives you access to packages. This should be used for porting or for configuring output attrs not otherwise supported by Flakelight.

To add example.${system}.test outputs to your flake, you could do the following:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      perSystem = pkgs: {
        example.test = pkgs.writeShellScript "test" "echo hello";
      };
    };
}

The above, with default systems, will generate example.x86_64-linux.test and example.aarch64-linux.test attributes.

nixpkgs.config

Type: AttrSet

This allows you to pass configuration options to the Nixpkgs instance used for building packages and calling perSystem.

For example, to allow building broken or unsupported packages, you can set the option as follows:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      nixpkgs.config = { allowBroken = true; allowUnsupportedSystem = true; };
    };
}

nixpkgs.overlays

Type: [Overlay]

This allows you to apply overlays to the Nixpkgs instance used for building packages and calling perSystem. withOverlays is a more flexible version of this option.

withOverlays

Type: [Overlay] | Overlay | (ModuleArgs -> [Overlay])

This allows you to apply overlays to the Nixpkgs instance used for building packages and calling perSystem.

It can be set to either a list of overlays or a single overlay.

For example, to apply the Emacs overlay and change the Zig version, you can set the option as follows:

{
  inputs = {
    flakelight.url = "github:nix-community/flakelight";
    emacs-overlay.url = "github:nix-community/emacs-overlay";
  };
  outputs = { flakelight, emacs-overlay, ... }:
    flakelight ./. {
      withOverlays = [
        emacs-overlay.overlays.default
        (final: prev: { zig = final.zig_0_9; })
      ];
    };
}

You can use the values from the overlays with other options:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      withOverlays = final: prev: { testValue = "hi"; };

      package = { writeShellScript, testValue }:
        writeShellScript "test" "echo ${testValue}";
    };
}

nixpkgs.patches

Type: [path | pathInStore]

This allows you to apply patches to the Nixpkgs instance used for building packages and calling perSystem.

For example, to apply a patch in the same directory named fix-hello.patch:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      nixpkgs.patches = [ ./fix-hello.patch ];
    };
}

packages

Types:
  package: PackageDef
  packages: (AttrsOf PackageDef) | (ModuleArgs -> (AttrsOf PackageDef))
  pname: Str

The package and packages options allow you to add packages. These are exported in the packages.${system} outputs, are included in overlays.default, and have build checks in checks.${system}.

package can be set to a package definition, and will set packages.default.

packages can be set to attrs of package definitions. If it is a function, it will additionally get a system arg in addition to module args, to allow conditionally including package definitions depending on the system.

By default, the packages.default package's name (its attribute name in the package set and overlay) is automatically determined from the derivation's pname. In order to use a different attribute name from the package pname, to set it in cases where it cannot be automatically determined, or to speed up uncached evaluation, the flakelight pname option can be set.

To set the default package, you can set the options as follows:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      package = { stdenv }:
        stdenv.mkDerivation {
          pname = "pkg1";
          version = "0.0.1";
          src = ./.;
          installPhase = "make DESTDIR=$out install";
        };
    };
}

The above will export packages.${system}.default attributes, add pkg1 to overlays.default, and export checks.${system}.packages-default.

You can also instead just directly set packages.default.

To set multiple packages, you can set the options as follows:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      packages = {
        default = { stdenv }:
          stdenv.mkDerivation {
            name = "pkg1";
            src = ./.;
            installPhase = "make DESTDIR=$out install";
          };
        pkg2 = { stdenv, pkg1, pkg3 }:
          stdenv.mkDerivation {
            name = "hello-world";
            src = ./pkg2;
            nativeBuildInputs = [ pkg1 pkg3 ];
            installPhase = "make DESTDIR=$out install";
          };
        pkg3 = { stdenv }:
          stdenv.mkDerivation {
            name = "hello-world";
            src = ./pkg3;
            installPhase = "make DESTDIR=$out install";
          };
      };
    };
}

The above will export packages.${system}.default, packages.${system}.pkg2, packages.${system}.pkg3 attributes, add pkg1, pkg2, and pkg3 to overlays.default, and export corresponding build checks.

To use the first example, but manually specify the package name:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      pname = "pkgs-attribute-name";
      package = { stdenv }:
        stdenv.mkDerivation {
          pname = "package-name";
          version = "0.0.1";
          src = ./.;
          installPhase = "make DESTDIR=$out install";
        };
    };
}

To add a package only for certain systems, you can take system as an arg as follows:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      packages = { system, ... }: if (system == "x86_64-linux") then {
        pkg1 = { stdenv }:
          stdenv.mkDerivation {
            name = "pkg1";
            src = ./.;
            installPhase = "make DESTDIR=$out install";
          };
      } else { };
    };
}

devShell

Type:
  devShell: Cfg | (Pkgs -> Cfg) | PackageDef | Derivation | (Pkgs -> Derivation)
  Cfg.packages: [Derivation] | (Pkgs -> [Derivation])
  Cfg.inputsFrom: [Derivation] | (Pkgs -> [Derivation])
  Cfg.shellHook: Str | (Pkgs -> Str)
  Cfg.env: (AttrsOf Str) | (Pkgs -> (AttrsOf Str))
  Cfg.stdenv: Stdenv | (Pkgs -> Stdenv)

The devshell options allow you to configure devShells.${system}.default. It is split up into options in order to enable multiple modules to contribute to its configuration.

devShell can alternatively be set to a package definition or derivation, which is then used as the default shell, overriding other options.

devShell can also be set to a function that takes the package set and returns an attrSet of the devShell configuration options or a derivation.

The options available are as follows:

devShell.packages is a list of packages to add to the shell. It can optionally be a function taking the package set and returning such a list.

devShell.inputsFrom is a list of packages whose deps should be in the shell. It can optionally be a function taking the package set and returning such a list.

devShell.shellHook is a string that provides bash code to run in shell initialization. It can optionally be a function taking the package set and returning such a string.

devShell.hardeningDisable is a list of hardening options to disable. Setting it to ["all"] disables all Nix hardening.

devShell.env is for setting environment variables in the shell. It is an attribute set mapping variables to values. It can optionally be a function taking the package set and returning such an attribute set.

devShell.stdenv is the stdenv package used for the shell. It can optionally be a function takeing the package set and returning the stdenv to use.

For example, these can be configured as follows:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      devShell = pkgs: {
        # Include build deps of emacs
        inputsFrom = [ pkgs.emacs ];
        # Add coreutils to the shell
        packages = [ pkgs.coreutils ];
        # Add shell hook. Can be a function if you need packages
        shellHook = ''
          echo Welcome to example shell!
        '';
        # Set an environment var. `env` can be an be a function
        env.TEST_VAR = "test value";
        stdenv = pkgs.clangStdenv;
      };
    };
}

The above exports devShells.${system}.default outputs.

To add the build inputs of one of your packages, you can do as follows:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      package = { stdenv }:
        stdenv.mkDerivation {
          pname = "pkg1";
          version = "0.0.1";
          src = ./.;
          installPhase = "make DESTDIR=$out install";
        };
      devShell = {
        inputsFrom = pkgs: [ pkgs.pkg1 ];
      };
    };
}

To override the devShell, you can use a package definition as such:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      devShell = { mkShell, hello }: mkShell {
        packages = [ hello ];
      };
    };
}

devShells

Type:
  devShells: (AttrsOf (PackageDef | Cfg | (Pkgs -> Cfg)) |
             (ModuleArgs -> (AttrsOf (PackageDef | Cfg | (Pkgs -> Cfg))))
  Cfg.packages: [Derivation] | (Pkgs -> [Derivation])
  Cfg.inputsFrom: [Derivation] | (Pkgs -> [Derivation])
  Cfg.shellHook: Str | (Pkgs -> Str)
  Cfg.env: (AttrsOf Str) | (Pkgs -> (AttrsOf Str))
  Cfg.stdenv: Stdenv | (Pkgs -> Stdenv)

The devShells option allows you to set additional devShell outputs. The values each shell can be set to are the same as described above for the devShell option.

For example, using the configuration options:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      devShells.testing = {
        packages = pkgs: [ pkgs.coreutils ];
        env.TEST_VAR = "in testing shell";
      };
    };
}

For example, using a package definition:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      devShells.testing = { mkShell, coreutils }:
        mkShell {
          packages = [ coreutils ];
          env.TEST_VAR = "in testing shell";
        };
    };
}

The above flakes export devShells.${system}.testing outputs.

overlays

Types:
  overlay: Overlay
  overlays: (AttrsOf Overlay) | (ModuleArgs -> (AttrsOf Overlay)

The overlay and overlays options allow you to configure overlays outputs.

Multiple provided overlays for an output are merged.

The overlay option adds the overlay to overlays.default.

The overlays option allows you to add overlays to overlays outputs.

For example, to add an overlay to overlays.default, do the following:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      overlay = final: prev: { testValue = "hello"; };
    };
}

The above results in overlays.default output containing testValue.

To configure other overlays:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      overlays.cool = final: prev: { testValue = "cool"; };
    };
}

The above results in a overlays.cool output.

checks

Types:
  checks: (AttrsOf Check) | (Pkgs -> (AttrsOf Check))
  Check: Str | (Pkgs -> Str) | Derivation | (Pkgs -> Derivation)

The checks option allows you to add checks for checks.${system} attributes.

It can be set to an attribute set of checks, which can be functions, derivations, or strings.

If a check is a derivation, it will be used as is.

If a check is a string, it will be included in a bash script that runs it in a copy of the source directory, and succeeds if the no command in the string errored.

If a check is a function, it will be passed packages, and should return one of the above.

For example:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      checks = {
        # Check that succeeds if the source contains the string "hi"
        hi = { rg, ... }: "${rg}/bin/rg hi";
        # Check that emacs builds
        emacs = pkgs: pkgs.emacs;
      };
    };
}

apps

Types:
  app: App'
  apps: (AttrsOf App') | (Pkgs -> (AttrsOf App'))
  App': Str | (Pkgs -> Str) | App | (Pkgs -> App)

The app and apps options allow you to set apps.${system} outputs.

apps is an attribute set of apps or a function that takes packages and returns an attribute set of apps. If the app value is a function, it is passed packages. If the app value or function result is a string, it is converted to an app.

app sets apps.default.

For example:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      apps = {
        emacs = pkgs: "${pkgs.emacs}/bin/emacs";
        bash = pkgs: { type = "app"; program = "${pkgs.bash}/bin/bash"; };
      };
    };
}

Alternatively, the above can be written as:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      apps = { emacs, bash, ... }: {
        emacs = "${emacs}/bin/emacs";
        bash = { type = "app"; program = "${bash}/bin/bash"; };
      };
    };
}

templates

Types:
  template: Template | (ModuleArgs -> Template)
  templates: (AttrsOf (Template | (ModuleArgs -> Template))) |
             (ModuleArgs -> (AttrsOf (Template | (ModuleArgs -> Template))))

The template and templates options allow you to set templates outputs.

templates is an attribute set to template values.

template sets templates.default.

For example:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      templates.test-template = {
        path = ./test;
        description = "test template";
      };
    };
}

legacyPackages

Type: Pkgs -> Pkgs

The legacyPackages option allows you to configure the flake's legacyPackages output. It can be set to a function that takes the package set and returns the package set to be used as the corresponding system's legacyPackages output.

For example:

{
  inputs = {
    flakelight.url = "github:nix-community/flakelight";
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
  };
  outputs = { flakelight, nixpkgs, ... }:
    flakelight ./. {
      legacyPackages = pkgs: nixpkgs.legacyPackages.${pkgs.system};
    };
}

To export the package set used for calling package definitions and other options that take functions passed the package set, you can do the following:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      legacyPackages = pkgs: pkgs;
    };
}

formatter

Type: null | Pkgs -> Derivation

The formatter option allows you to set formatter.${system} outputs. It can be set to a function that takes packages and returns the package to use. This overrides the formatters functionality described below though, so for configuring formatters for a file type, you likely want to use formatters instead.

For example, to use a custom formatting command:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      formatter = pkgs: pkgs.writeShellScriptBin "format-script" ''
        # Perform formatting (`nix fmt` calls the script with `.` as arg)
      '';
    };
}

formatters

Type: (AttrsOf Str) | (Pkgs -> (AttrsOf Str))

The formatters option allows you to configure formatting tools that will be used by nix fmt. If formatters are set, Flakelight will export formatter.${system} outputs which apply all the configured formatters.

By default, nix files are formatted with nixfmt.

To disable the generated formatter, set formatter to null.

You can set formatters to an attribute set, for which the keys are a file name pattern and the value is the corresponding formatting command. formatters can optionally be a function that takes packages and returns the above.

Formatting tools should be added to devShell.packages; this enables easier use as described below, as well as allowing flake users to use the tools directly when in the devShell.

Formatters can be set to a plain string like "zig fmt" or a full path like "${pkgs.zig}/bin/zig fmt". Formatters set as plain strings have access to all packages in devShell.packages.

If building the formatter is slow due to building devShell packages, use full paths for the formatters; the devShell packages are only included if a formatting option is set to a plain string.

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      devShell.packages = pkgs: [ pkgs.rustfmt pkgs.zig ];
      formatters = {
        "*.rs" = "rustfmt";
        "*.zig" = "zig fmt";
      };
    };
}

bundlers

Types:
  bundler: Bundler | (Pkgs -> Bundler)
  bundlers: (AttrsOf (Bundler | (Pkgs -> Bundler))) |
            (ModuleArgs -> (AttrsOf (Bundler | (Pkgs -> Bundler))))

The bundler and bundlers options allow you to set bundlers.${system} outputs.

Each bundler value can be either a bundler function or a function that takes the package set and returns a bundler function.

bundlers is an attribute set of bundler values or a function that takes packages and returns an attribute set of bundler values.

bundler sets bundlers.default.

For example, a bundler that returns the passed package:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      bundler = x: x;
    };
}

As another example, a bundler that always returns hello:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      bundlers = { hello, ... }: {
        hello = x: hello;
      };
    };
}

To write the above using autoloads, can use the following:

# nix/bundlers/hello.nix
{ hello, ... }: x: hello;

nixosConfigurations

Type: (AttrsOf (NixOSArgs | NixOSConfig |
        (ModuleArgs -> (NixOSArgs | NixOSConfig)))) |
      (ModuleArgs -> (AttrsOf (NixOSArgs | NixOSConfig |
                       (ModuleArgs -> (NixOSArgs | NixOSConfig)))))

The nixosConfigurations attribute lets you set outputs for NixOS systems and home-manager users.

It should be set to an attribute set. Each value should be a set of nixpkgs.lib.nixosSystem args, the result of calling nixpkgs.lib.nixosSystem, or a function that takes moduleArgs and returns one of the prior.

When using a set of nixpkgs.lib.nixosSystem args, NixOS modules will have access to a flake module arg equivalent to moduleArgs plus inputs' and outputs'. Flakelight's pkgs attributes, withOverlays, and packages will also be available in the NixOS instance's pkgs, and Flakelight's nixpkgs config will apply to it as well.

When using the result of calling nixpkgs.lib.nixosSystem, the config.propagationModule value can be used as a NixOS module to gain the above benefits.

For example:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. ({ lib, config, ... }: {
      nixosConfigurations.test-system = {
        modules = [{
          nixpkgs.hostPlatform.system = "x86_64-linux";
          system.stateVersion = "25.05";
        }];
      };
    });
}

homeConfigurations

Type: (AttrsOf (HomeArgs | HomeConfig |
        (ModuleArgs -> (HomeArgs | HomeConfig)))) |
      (ModuleArgs -> (AttrsOf (HomeArgs | HomeConfig |
                       (ModuleArgs -> (HomeArgs | HomeConfig)))))

The homeConfigurations attribute lets you set outputs for NixOS systems and home-manager users.

It should be set to an attribute set. Each value should be a set of home-manager.lib.homeManagerConfiguration args, the result of calling home-manager.lib.homeManagerConfiguration, or a function that takes moduleArgs and returns one of the prior.

When using a set of homeManagerConfiguration args, it is required to include system (pkgs does not need to be included), and inputs.home-manager must be set. home-manager modules will have access to a flake module arg equivalent to moduleArgs plus inputs' and outputs'. Flakelight's pkgs attributes, withOverlays, and packages will also be available in the home-manager instance's pkgs, and Flakelight's nixpkgs config will apply to it as well.

When using the result of calling homeManagerConfiguration, the config.propagationModule value can be used as a home-manager module to gain the above benefits.

For example:

{
  inputs = {
    flakelight.url = "github:nix-community/flakelight";
    home-manger.url = "github:nix-community/home-manager";
  };
  outputs = { flakelight, home-manager, ... }@inputs:
    flakelight ./. ({ config, ... }: {
      inherit inputs;
      homeConfigurations.username = {
        system = "x86_64-linux";
        modules = [{ home.stateVersion = "24.05"; }];
      };
    });
}

nixosModules, homeModules, and flakelightModules

Types:
  nixosModule: Module
  nixosModules: (AttrsOf Module) | (ModuleArgs -> (AttrsOf Module))
  homeModule: Module
  homeModules: (AttrsOf Module) | (ModuleArgs -> (AttrsOf Module))
  flakelightModule: Module
  flakelightModules: (AttrsOf Module) | (ModuleArgs -> (AttrsOf Module))

The nixosModules, homeModules, and flakelightModules options allow you to configure the corresponding outputs.

The nixosModule, homeModule, and flakelightModule options set the default attribute of the corresponding above option.

For example:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. ({ lib, ... }: {
      nixosModule = { system, lib, pkgs, ... }: {
        # nixos module configuration
      };
    });
}

These can be paths, which is preferred as it results in better debug output:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. ({ lib, ... }: {
      nixosModule = ./module.nix;
      homeModules = {
        default = ./home.nix;
        emacs = ./emacs.nix;
      }
    });
}

lib

Type: AttrSet | (ModuleArgs -> AttrSet)

The lib option allows you to configure the flake's lib output.

For example:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      lib = {
        addFive = x: x + 5;
        addFour = x: x + 4;
      };
    };
}

functor

Type: Outputs -> Any -> Any

The functor option allows you to make your flake callable.

If it is set to a function, that function will be set as the __functor attribute of your flake outputs.

Flakelight uses it so that calling your flakelight input calls flakelight.lib.mkFlake.

As an example:

{
  inputs.flakelight.url = "github:nix-community/flakelight";
  outputs = { flakelight, ... }:
    flakelight ./. {
      outputs.testvalue = 5;
      functor = self: x: x + self.testvalue;
    }
}

With the above flake, another flake that has imports it with the name addFive would be able to call addFive 4 to get 9.

flakelight

Types:
  flakelight.editorconfig: Bool

This option has options for configuring Flakelight's defaults.

flakelight.editorconfig can be set to false to disable the editorconfig check that is added if editorconfig configuration is detected.

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lib

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Module arguments

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systems

nixDir

outputs

perSystem

nixpkgs.config

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withOverlays

nixpkgs.patches

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