diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..1d953f4
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use nix
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..8361884
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.direnv/*
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..1c97ea2
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,9 @@
+{ pkgs ? import <nixpkgs> {} }:
+  pkgs.mkShell {
+    nativeBuildInputs = with pkgs.buildPackages; [
+      python3.pkgs.pyserial
+      (writeShellScriptBin "flash-thb1" ''
+        python3 rdwr_phy62x2.py -p /dev/ttyUSB0 -b 115200 -e -r wh ./bin/BOOT_THB1_v*.hex
+      '')
+    ];
+}