diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..917110b
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,20 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+  outputs = {
+    self,
+    nixpkgs,
+  } @ inputs: let
+    system = "x86_64-linux";
+    pkgs = nixpkgs.legacyPackages."${system}";
+  in {
+    packages."${system}".default = pkgs.writeShellApplication {
+      name = "hello_world";
+
+      runtimeInputs = with pkgs; [sane-backends brscan5 ghostscript];
+
+      text = builtins.readFile ./scanbuddy.bash;
+    };
+  };
+}
diff --git a/scanbuddy.bash b/scanbuddy.bash
index 06565ab..54b57e0 100755
--- a/scanbuddy.bash
+++ b/scanbuddy.bash
@@ -1,9 +1,5 @@
 #!/usr/bin/env bash
 
-# device="brother5:bus2;dev2"
-device=$(scanimage -f "%d%n" | grep brother5 | head -n 1)
-echo "Selecting scanner '$device'"
-
 # option values for the brother DS-740D scanner
 simplex_source='Automatic Document Feeder(left aligned)'
 duplex_source='Automatic Document Feeder(left aligned,Duplex)'
@@ -25,6 +21,10 @@ last_out_file="out$current_pageno.pdf"
 next_out_file="out$((current_pageno+1)).pdf"
 
 scan() {
+  # device="brother5:bus2;dev2"
+  device=$(scanimage -f "%d%n" | grep brother5 | head -n 1)
+  echo "Selecting scanner '$device'"
+
   usage() {
     echo "scanbuddy.bash scan -d -r <resolution($resolution)> -b <c|b|g>"
   }
@@ -68,7 +68,7 @@ scan() {
 
   echo "Scanning to '$next_out_file'..."
   scanimage \
-    --device-name=$device \
+    --device-name="$device" \
     --format=pdf \
     --output-file="$next_out_file" \
     --mode="$scanner_mode" \
@@ -77,14 +77,36 @@ scan() {
     -x 210 -y 297 # A4 
 }
 
+if [ "$#" -lt 1 ]; then
+  echo "You need an argument!"
+  exit 1
+fi
+
 case "$1" in
   scan)
     scan "${@:2}"
     ;;
   unscan)
-    rm "$current_pageno"
+    rm "$last_out_file"
     ;;
   dispatch)
+    readarray -d '' out_files < <(find . -regextype posix-awk -regex "\./out[0-9]+\.pdf" -print0 | sort -Vz)
+    combined_file=$(mktemp --suff="_scanbuddy.pdf")
+    gs -q -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE="$combined_file" -dBATCH "${out_files[@]}"
+    echo "Merged pdf written to $combined_file"
+
+    # send to paperless
+    PAPERLESS_STATUS=$(curl \
+      -H "Authorization: Token $PAPERLESS_TOKEN" \
+      -F document=@"$combined_file" \
+      "$([ -v PAPERLESS_TAG ] && echo "-F tags=$PAPERLESS_TAG")" \
+      "${PAPERLESS_URL}/api/documents/post_document/") || FAILED=1
+
+    if [ -v FAILED ]; then
+      echo "Paperless failed with message:\n$PAPERLESS_STATUS"
+    else
+      echo "Paperless consumption job: '$PAPERLESS_STATUS'"
+    fi
     ;;
   *)
     echo "Usage: scanbuddy"