nix3-flake-init(1) General Commands Manual nix3-flake-init(1)

Warning
This program is experimental and its interface is subject to change.

nix flake init - create a flake in the current directory from a template

nix flake init [option…]

•
Create a flake using the default template:
# nix flake init
•
List available templates:
# nix flake show templates
•
Create a flake from a specific template:
# nix flake init -t templates#simpleContainer

This command creates a flake in the current directory by copying the files of a template. It will not overwrite existing files. The default template is templates#templates.default, but this can be overridden using -t.

A flake can declare templates through its templates output attribute. A template has the following attributes:

  • description: A one-line description of the template, in CommonMark syntax.
  • path: The path of the directory to be copied.
  • welcomeText: A block of markdown text to display when a user initializes a new flake based on this template.

Here is an example:

outputs = { self }: {
  templates.rust = {
    path = ./rust;
    description = "A simple Rust/Cargo project";
    welcomeText = ''
      # Simple Rust/Cargo Template
      ## Intended usage
      The intended usage of this flake is...
      ## More info
      - [Rust language](https://www.rust-lang.org/)
      - [Rust on the NixOS Wiki](https://wiki.nixos.org/wiki/Rust)
      - ...
    '';
  };
  templates.default = self.templates.rust;
}

•
--template / -t template
The template to use.

•
--arg name expr
Pass the value expr as the argument name to Nix functions.
•
--arg-from-file name path
Pass the contents of file path as the argument name to Nix functions.
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--arg-from-stdin name
Pass the contents of stdin as the argument name to Nix functions.
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--argstr name string
Pass the string string as the argument name to Nix functions.
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--debugger
Start an interactive environment if evaluation fails.
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--eval-store store-url
The URL of the Nix store to use for evaluation, i.e. to store derivations (.drv files) and inputs referenced by them.
•
--impure
Allow access to mutable paths and repositories.
•
--include / -I path
Add path to search path entries used to resolve lookup paths
This option may be given multiple times.
Paths added through -I take precedence over the nix-path configuration setting and the NIX_PATH environment variable.
•
--override-flake original-ref resolved-ref
Override the flake registries, redirecting original-ref to resolved-ref.
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--debug
Set the logging verbosity level to ‘debug’.
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--log-format format
Set the format of log output; one of raw, internal-json, bar or bar-with-logs.
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--print-build-logs / -L
Print full build logs on standard error.
•
--quiet
Decrease the logging verbosity level.
•
--verbose / -v
Increase the logging verbosity level.

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--help
Show usage information.
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--offline
Disable substituters and consider all previously downloaded files up-to-date.
•
--option name value
Set the Nix configuration setting name to value (overriding nix.conf).
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--refresh
Consider all previously downloaded files out-of-date.
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--repair
During evaluation, rewrite missing or corrupted files in the Nix store. During building, rebuild missing or corrupted store paths.
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--version
Show version information.

Note

See man nix.conf for overriding configuration settings with command line flags.