diff --git a/launch/README.md b/launch/README.md
index af8ed851..5464ff5a 100644
--- a/launch/README.md
+++ b/launch/README.md
@@ -2,22 +2,14 @@
 
 ## usage
 
-<-- TODO: port to just -->
-
-### updating npins
+before using other commands, if not using direnv:
 
 ```sh
-$ cd launch/
-$ echo "$(nix eval --json -f ../npins)" > .npins.json
+nix-shell
 ```
 
-### local development
+then to initialize, or after updating pins or TF providers:
 
 ```sh
-$ nix-shell
-$ eval "$(ssh-agent -s)"
-# set your ssh key, e.g.:
-$ ssh_key="$(readlink -f ~/.ssh/id_ed25519)"
-$ rm -rf .terraform/
-$ tofu init
+setup
 ```
diff --git a/launch/default.nix b/launch/default.nix
index 139b4300..b1700481 100644
--- a/launch/default.nix
+++ b/launch/default.nix
@@ -12,6 +12,11 @@
 }:
 let
   inherit (pkgs) lib;
+  setup = pkgs.writeScriptBin "setup" ''
+    echo '${lib.strings.toJSON sources}' > .npins.json
+    rm -rf .terraform/
+    tofu init
+  '';
 in
 {
   # shell for testing TF directly
@@ -19,6 +24,7 @@ in
     packages = [
       (import ./tf.nix { inherit lib pkgs; })
       pkgs.jaq
+      setup
     ];
   };