$ devenv
https://devenv.sh 1.9.0: Fast, Declarative, Reproducible, and Composable Developer Environments

Usage: devenv [OPTIONS] [COMMAND]

Commands:
  init       Scaffold devenv.yaml, devenv.nix, .gitignore and .envrc.
  generate   Generate devenv.yaml and devenv.nix using AI
  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.
  mcp        Launch Model Context Protocol server for AI assistants
  help       Print this message or the help of the given subcommand(s)

Options:
  -V, --version
          Print version information and exit

  -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:            The default human-readable log format used in the CLI
          - tracing-full:   A verbose structured log format used for debugging
          - tracing-pretty: A pretty human-readable log format used for debugging

  -j, --max-jobs <MAX_JOBS>
          Maximum number of Nix builds at any time.
          
          [default: 8]

  -u, --cores <CORES>
          Maximum number CPU cores being used by a single build.
          
          [default: 2]

  -s, --system <SYSTEM>
          [default: x86_64-linux]

  -i, --impure
          Relax the hermeticity of the environment.

      --no-eval-cache
          Disable caching of Nix evaluation results.

      --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 <NAME> <VALUE>
          Pass additional options to nix commands.
          
          These options are passed directly to Nix using the --option flag.
          See `man nix.conf` for the full list of available options.
          
          Examples:
            --nix-option sandbox false
            --nix-option keep-outputs true
            --nix-option system x86_64-darwin

  -o, --override-input <NAME> <URI>
          Override inputs in devenv.yaml.
          
          Examples:
            --override-input nixpkgs github:NixOS/nixpkgs/nixos-unstable
            --override-input nixpkgs path:/path/to/local/nixpkgs

  -O, --option <OPTION> <VALUE>
          Override configuration options with typed values.
          
          OPTION must include a type: <attribute>:<type>
          Supported types: string, int, float, bool, path, pkg, pkgs
          
          Examples:
            --option languages.rust.channel:string beta
            --option services.postgres.enable:bool true
            --option languages.python.version:string 3.10
            --option packages:pkgs "ncdu git"

  -P, --profile <PROFILE>
          Activate one or more profiles defined in devenv.nix.
          
          Profiles allow you to define different configurations that can be merged with your base configuration.
          
          See https://devenv.sh/profiles for more information.
          
          Examples:
            --profile python-3.14
            --profile backend --profile fast-startup

  -h, --help
          Print help (see a summary with '-h')