diff --git a/launch/README.md b/launch/README.md
index a3c83086..94cea9eb 100644
--- a/launch/README.md
+++ b/launch/README.md
@@ -14,6 +14,10 @@ $ echo "{\"terraform-nixos\": $(nix-instantiate --eval --json -E '(import ../npi
 
 ```sh
 $ nix-shell
+$ eval "$(ssh-agent -s)"
+# set your ssh key, e.g.:
+$ ssh_key="$(readlink -f ~/.ssh/id_ed25519)"
+$ echo "{\"ssh_private_key_file\": \"${ssh_key}\", \"deploy_environment\": {\"SSH_AUTH_SOCK\": \"${SSH_AUTH_SOCK}\"}}" > .auto.tfvars.json
 $ rm -rf .terraform/
 $ tofu init
 ```