fh, the official FlakeHub CLI

fh is a scrappy CLI for searching FlakeHub and adding new inputs to your Nix flakes.

Usage

Using fh from FlakeHub:

nix shell "https://flakehub.com/f/DeterminateSystems/fh/*.tar.gz"

[!NOTE] This builds fh locally on your computer. Pre-built binaries aren't yet available.

Installation

NixOS

To make the fh CLI readily available on a NixOS system:

{
  description = "My NixOS config.";

  inputs.fh.url = "https://flakehub.com/f/DeterminateSystems/fh/*.tar.gz";
  inputs.nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/0.2305.*.tar.gz";

  outputs = { nixpkgs, fh, ... } @ inputs: {
    nixosConfigurations.nixos = nixpkgs.lib.nixosSystem {
      system = "x86_64-linux";
      modules = [
        {
          environment.systemPackages = [ fh.packages.x86_64-linux.default ];
        }

        # ... the rest of your modules here ...
      ];
    };
  };
}

Using fh

You can use fh to:

• Log into FlakeHub
• Initialize a new flake.nix
• Add flake inputs to your flake.nix
• Resolve flake references to store paths
• Search FlakeHub flakes
• List available releases and flakes, organizations, and versions
• List flakes by label

Log into FlakeHub

fh is the standard way to set up your local Nix to use FlakeHub's advanced features like FlakeHub Cache and private flakes:

fh login

This will prompt you for a FlakeHub token that you can obtain under Tokens on your user settings page. Click New to create a new token, provide your desired configuration, copy the token, paste it into the prompt, and follow the remaining instructions.

Initialize a new flake.nix from scratch

fh init generates a new flake.nix file for you using a combination of:

1. Your responses to interactive questions
2. The contents of the repository in which you run the command.

To create a flake.nix, navigate to the directory where you want to create it and run fh init (or specify a different directory using the --root option). Respond to the prompts it provides you and at the end fh will write a flake.nix to disk.

fh init has built-in support for the following languages:

• Elm
• Go
• Java
• JavaScript
• PHP
• Python
• Ruby
• Rust
• Zig

[!NOTE] The fh init command operates on a best-guess basis and is opinionated in its suggestions. It's intended less as a comprehensive flake creation solution and more as a helpful kickstarter.

Add a flake published to FlakeHub to your flake.nix

fh add adds the most current release of the specified flake to your flake.nix and updates the outputs function to accept it. This would add the current release of Nixpkgs to your flake:

fh add nixos/nixpkgs

The resulting flake.nix would look something like this:

{
  description = "My new flake.";

  inputs.nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/0.2305.490449.tar.gz";

  outputs = { nixpkgs, ... } @ inputs: {
    # Fill in your outputs here
  };
}

Resolve flake references to store paths

You can resolve flake references on FlakeHub to Nix store paths using the fh resolve command:

fh resolve "omnicorp/devtools/0.1.0#packages.x86_64-linux.cli"
/nix/store/1ab797rfbdcjzissxrsf25rqy0l8mksq-cli-0.1.0

You can only use fh resolve with flake releases for which include-output-paths has been set to true. Here's an example flakehub-push configuration:

- name: Publish to FlakeHub
  uses: determinatesystems/flakehub-push@main
  with:
    visibility: "public" # or "unlisted" or "private"
    include-output-paths: true

The fh resolve command is most useful when used in conjunction with FlakeHub Cache. If the cache is enabled on the flake and the current Nix user is logged into FlakeHub, then resolved store paths are also available to Nix. Under those conditions, you can, for example, apply a NixOS configuration published to FlakeHub:

# Build the derivation
nix build \
  --max-jobs 0 \
  --profile /nix/var/nix/profiles/system \
  $(fh resolve "my-org/my-nixos-configs#nixosConfigurations.my-dev-workstation")

# Apply the configuration
/nix/var/nix/profiles/system/bin/switch-to-configuration switch

Apply configurations to the current system

The fh apply command enables you to apply a configuration for one of the following systems to the current host:

• NixOS
• Home Manager
• nix-darwin

For all three systems, you only need to supply a flake output reference for the configuration and fh does the rest.

NixOS

On a NixOS system, you can use fh apply nixos to apply a configuration from an output path:

fh apply nixos "my-org/system-configs/0.1#nixosConfigurations.staging-box"

If you don't specify a flake output path, fh apply nixos defaults to nixosConfigurations.$(hostname). These two commands are thus equivalent:

fh apply nixos "my-org/system-configs/0.1#nixosConfigurations.$(hostname)"
fh apply nixos "my-org/system-configs/0.1"

fh apply nixos first resolves the supplied output reference to a store path, builds the switch-to-configuration script for that path, and then runs switch-to-configuration switch by default. You can also supply a different command from switch (boot, test, or dry-activate). Here's an example:

fh apply nixos "my-org/system-configs/0.1" boot

Home Manager

If you're on a system that uses Home Manager, you can use fh apply home-manager to apply a configuration from an output path:

fh apply home-manager "my-org/home-configs/0.1#homeConfigurations.standard-home-config"

If you don't specify a flake output path, fh apply home-manager defaults to homeConfigurations.$(whoami). These two commands are thus equivalent:

fh apply home-manager "my-org/home-configs/0.1#homeConfigurations.$(whoami)"
fh apply home-manager "my-org/home-configs/0.1"

fh apply home-manager first resolves the supplied output reference to a store path, builds the activate script for that path, and then runs it.

nix-darwin

If you're on a macOS system that uses nix-darwin, you can use fh apply nix-darwin to apply a configuration from an output path:

fh apply nix-darwin "my-org/macos-configs/0.1#darwinConfigurations.justme-aarch64-darwin"

If you don't specify a flake output path, fh apply nix-darwin defaults to darwinConfigurations.${devicename}.system, where devicename is the output of scutil --get LocalHostName. These two commands are thus equivalent:

fh apply nix-darwin "my-org/macos-configs/0.1#darwinConfigurations.$(scutil --get LocalHostName)"
fh apply nix-darwin "my-org/macos-configs/0.1"

fh apply nix-darwin first resolves the supplied output reference to a store path, builds the darwin-rebuild script for that path, and then runs darwin-rebuild activate.

Searching published flakes

You can search publicly listed flakes using the fh search command and passing in a search query. Here's an example:

fh search rust

+---------------------------------------------------------------------------------+
| Flake                      FlakeHub URL                                         |
+---------------------------------------------------------------------------------+
| astro/deadnix              https://flakehub.com/flake/astro/deadnix             |
| carlthome/ml-runtimes      https://flakehub.com/flake/carlthome/ml-runtimes     |
| ipetkov/crane              https://flakehub.com/flake/ipetkov/crane             |
| kamadorueda/alejandra      https://flakehub.com/flake/kamadorueda/alejandra     |
| nix-community/fenix        https://flakehub.com/flake/nix-community/fenix       |
| nix-community/lanzaboote   https://flakehub.com/flake/nix-community/lanzaboote  |
| nix-community/nix-init     https://flakehub.com/flake/nix-community/nix-init    |
| nix-community/nixpkgs-fmt  https://flakehub.com/flake/nix-community/nixpkgs-fmt |
| nix-community/patsh        https://flakehub.com/flake/nix-community/patsh       |
| ryanccn/nyoom              https://flakehub.com/flake/ryanccn/nyoom             |
+---------------------------------------------------------------------------------+

fh search supports arbitrary search strings. An example:

fh search "rust nixos"

Listing releases

fh list releases provides a list of a flake's releases.

fh list releases nixos/nixpkgs

+------------------------------------------------------------+
| Version                                                    |
+------------------------------------------------------------+
| 0.1.428801+rev-2788904d26dda6cfa1921c5abb7a2466ffe3cb8c    |
| 0.1.429057+rev-42337aad353c5efff4382d7bf99deda491459845    |
| 0.1.429304+rev-27ccd29078f974ddbdd7edc8e38c8c8ae003c877    |
| 0.1.429553+rev-5dc7114b7b256d217fe7752f1614be2514e61bb8    |
| 0.1.429868+rev-a115bb9bd56831941be3776c8a94005867f316a7    |
| ...                                                        |
+------------------------------------------------------------+

Listing flakes, organizations, and versions

fh list flakes, fh list orgs, and fh list versions enumerate flakes, organizations, and flake versions on FlakeHub, respectively.

List flakes

fh list flakes

+---------------------------------------------------------------------------------------------------------------+
| Flake                                     FlakeHub URL                                                        |
+---------------------------------------------------------------------------------------------------------------+
| ajaxbits/audiobookshelf                   https://flakehub.com/flake/ajaxbits/audiobookshelf                  |
| ajaxbits/tone                             https://flakehub.com/flake/ajaxbits/tone                            |
| astro/deadnix                             https://flakehub.com/flake/astro/deadnix                            |
| ...                                       ...                                                                 |
+---------------------------------------------------------------------------------------------------------------+

List orgs

fh list orgs

+-------------------------------------------------------------------------+
| Organization            FlakeHub URL                                    |
+-------------------------------------------------------------------------+
| ajaxbits                https://flakehub.com/org/ajaxbits               |
| astro                   https://flakehub.com/org/astro                  |
| ...                     ...                                             |
+-------------------------------------------------------------------------+

List versions

Your can list versions of a flake by passing the flake name and a version requirement to fh list versions:

fh list versions <flake> <version_req>

Here's an example:

fh list versions DeterminateSystems/flake-checker "0.1.*"

+------------------------------------------------------------------------------------------------------+
| Simplified version  FlakeHub URL                                                        Full version |
+------------------------------------------------------------------------------------------------------+
| 0.1.0               https://flakehub.com/flake/DeterminateSystems/flake-checker/0.1.0   0.1.0        |
| 0.1.1               https://flakehub.com/flake/DeterminateSystems/flake-checker/0.1.1   0.1.1        |
| 0.1.2               https://flakehub.com/flake/DeterminateSystems/flake-checker/0.1.2   0.1.2        |
| ...                 ...                                                                 ...          |
+------------------------------------------------------------------------------------------------------+

List by label

You can list flakes by label using the fh list label comand:

fh list label <label>

Here's an example:

fh list label python

+-------------------------------------------------------------------------------+
| Flake                     FlakeHub URL                                        |
+-------------------------------------------------------------------------------+
| nix-community/poetry2nix  https://flakehub.com/flake/nix-community/poetry2nix |
+-------------------------------------------------------------------------------+

Shell completion

You can generate shell completion scripts using the fh completion command:

fh completion <shell>

Here's an example:

fh completion bash

These shells are supported:

• Bash
• Elvish
• Fish
• Powershell
• zsh

A note on automation

Piping fh list commands to another program emits CSV instead of the stylized table.

You can apply the --json flag to each list command to produce JSON output.

License

Apache 2.0

Support

For support, email [email protected] or join our Discord.