diff --git a/justfile b/justfile
index 633263c..31aa607 100644
--- a/justfile
+++ b/justfile
@@ -1,25 +1,56 @@
+set positional-arguments # makes variables accesible as $1 $2 $@
 export GUM_FILTER_HEIGHT := "15"
-nom := `if command -v nom >/dev/null; then echo nom; else echo nix; fi`
+nom := `if [[ -t 1 ]] && command -v nom >/dev/null; then echo nom; else echo nix; fi`
+nix_eval_opts := "--log-format raw --option warn-dirty false"
 
 @_default:
   just "$(gum choose --ordered --header "Pick a recipie..." $(just --summary --unsorted))"
 
-check:
-  nix flake check --keep-going
+check *_:
+  nix flake check --keep-going "$@"
 
-build-machine machine=`just _a_machine`:
-  {{nom}} build .#nixosConfigurations.{{ machine }}.config.system.build.toplevel
+build-machine machine=`just _a_machine` *_:
+  {{nom}} build .#nixosConfigurations.{{ machine }}.config.system.build.toplevel "${@:2}"
 
-run-vm machine=`just _a_machine`:
-  nixos-rebuild build-vm --flake .#{{ machine }}
+run-vm machine=`just _a_machine` *_:
+  nixos-rebuild build-vm --flake .#{{ machine }} "${@:2}"
   QEMU_NET_OPTS="hostfwd=tcp::8080-:80,hostfwd=tcp::8081-:443,hostfwd=tcp::2222-:22" ./result/bin/run-*-vm
 
-@update-inputs:
-  nix eval .#inputs --apply builtins.attrNames --json \
-    | jq '.[]' -r \
-    | gum choose --no-limit --height=15 \
-    | xargs -L 1 nix flake lock --update-input
+@update-inputs *_:
+  @git reset flake.lock
+  @git restore flake.lock
+  nix eval {{nix_eval_opts}} --file flake.nix --apply 'x: builtins.attrNames x.inputs' --json \
+    | { printf "%s\n" --commit-lock-file; jq '.[]' -r | grep -vxF "self" ||:; } \
+    | gum choose --no-limit --header "Choose extra arguments:" \
+    | tee >(xargs -d'\n' echo + nix flake update "$@" >&2) \
+    | xargs -d'\n' nix flake update "$@"
+
+@repl $machine=`just _a_machine` *_:
+  set -v; nixos-rebuild --flake .#"$machine" repl "${@:2}"
+
+@eval $machine=`just _a_machine` $attrpath="system.build.toplevel.outPath" *_:
+  set -v; nix eval {{nix_eval_opts}} ".#nixosConfigurations.\"$machine\".config.$attrpath" --show-trace "${@:3}"
+
+@eval-vm $machine=`just _a_machine` $attrpath="system.build.toplevel.outPath" *_:
+  just eval "$machine" "virtualisation.vmVariant.$attrpath" "${@:3}"
 
 
+# helpers
+
+[no-exit-message]
 _a_machine:
-  nix eval .#nixosConfigurations --apply builtins.attrNames --json | jq .[] -r | gum filter
+  #!/usr/bin/env -S sh -euo pipefail
+  machines="$(
+    nix eval {{nix_eval_opts}} .#nixosConfigurations --apply builtins.attrNames --json | jq .[] -r
+  )"
+  [ -n "$machines" ] || { echo >&2 "ERROR: no machines found"; false; }
+  if [ -s .direnv/vars/last-machine.txt ]; then
+    machines="$(
+      grep <<<"$machines" -xF  "$(cat .direnv/vars/last-machine.txt)" ||:
+      grep <<<"$machines" -xFv "$(cat .direnv/vars/last-machine.txt)" ||:
+    )"
+  fi
+  choice="$(gum filter <<<"$machines")"
+  mkdir -p .direnv/vars
+  cat <<<"$choice" >.direnv/vars/last-machine.txt
+  cat <<<"$choice"