devenv.sh - Fast, Declarative, Reproducible, and Composable Developer Environments

Running devenv init generates devenv.nix:

{ pkgs, ... }:

{
  # https://devenv.sh/basics/
  env.GREET = "devenv";

  # https://devenv.sh/packages/
  packages = [ pkgs.git ];

  enterShell = ''
    hello
  '';

  # https://devenv.sh/tests/
  enterTest = ''
    echo "Running tests"
    git --version | grep --color=auto "${pkgs.git.version}"
  '';

  # https://devenv.sh/languages/
  languages.nix.enable = true;

  # https://devenv.sh/scripts/
  scripts.hello.exec = "echo hello from $GREET";

  # https://devenv.sh/services/
  services.postgres.enable = true;

  # https://devenv.sh/git-hooks/
  git-hooks.hooks.shellcheck.enable = true;

  # https://devenv.sh/processes/
  processes.ping.exec = "ping localhost";
}

And devenv shell activates the environment.

Commands

$ devenv
https://devenv.sh 1.3.1: Fast, Declarative, Reproducible, and Composable Developer Environments

Usage: devenv [OPTIONS] [COMMAND]

Commands:
  init       Scaffold devenv.yaml, devenv.nix, .gitignore and .envrc.
  shell      Activate the developer environment. https://devenv.sh/basics/
  update     Update devenv.lock from devenv.yaml inputs. http://devenv.sh/inputs/
  search     Search for packages and options in nixpkgs. https://devenv.sh/packages/#searching-for-a-file
  info       Print information about this developer environment.
  up         Start processes in the foreground. https://devenv.sh/processes/
  processes  Start or stop processes. https://devenv.sh/processes/
  tasks      Run tasks. https://devenv.sh/tasks/
  test       Run tests. http://devenv.sh/tests/
  container  Build, copy, or run a container. https://devenv.sh/containers/
  inputs     Add an input to devenv.yaml. https://devenv.sh/inputs/
  repl       Launch an interactive environment for inspecting the devenv configuration.
  gc         Delete previous shell generations. See https://devenv.sh/garbage-collection
  build      Build any attribute in devenv.nix.
  direnvrc   Print a direnvrc that adds devenv support to direnv. See https://devenv.sh/automatic-shell-activation.
  version    Print the version of devenv.
  help       Print this message or the help of the given subcommand(s)

Options:
  -V, --version
          Print version information
  -v, --verbose
          Enable additional debug logs.
  -q, --quiet
          Silence all logs
      --log-format <LOG_FORMAT>
          Configure the output format of the logs. [default: cli] [possible values: cli, tracing-full]
  -j, --max-jobs <MAX_JOBS>
          Maximum number of Nix builds at any time. [default: 5]
  -u, --cores <CORES>
          Maximum number CPU cores being used by a single build. [default: 2]
  -s, --system <SYSTEM>
          [default: aarch64-darwin]
  -i, --impure
          Relax the hermeticity of the environment.
      --eval-cache
          Cache the results of Nix evaluation.
      --refresh-eval-cache
          Force a refresh of the Nix evaluation cache.
      --offline
          Disable substituters and consider all previously downloaded files up-to-date.
  -c, --clean [<CLEAN>...]
          Ignore existing environment variables when entering the shell. Pass a list of comma-separated environment variables to let through.
      --nix-debugger
          Enter the Nix debugger on failure.
  -n, --nix-option <NIX_OPTION> <NIX_OPTION>
          Pass additional options to nix commands, see `man nix.conf` for full list.
  -o, --override-input <OVERRIDE_INPUT> <OVERRIDE_INPUT>
          Override inputs in devenv.yaml.
  -h, --help
          Print help (see more with '--help')

Documentation

• Getting Started
• Basics
• Roadmap
• Blog
• devenv.yaml reference
• devenv.nix reference
• Contributing