diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..ab5f113
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1755186698,
+        "narHash": "sha256-wNO3+Ks2jZJ4nTHMuks+cxAiVBGNuEBXsT29Bz6HASo=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "fbcf476f790d8a217c3eab4e12033dc4a0f6d23c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..a319105
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,15 @@
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    inputs:
+    let
+      system = "x86_64-linux";
+      pkgs = import inputs.nixpkgs { inherit system; };
+    in
+    {
+      devShells.${system}.default = (import ./shell.nix { inherit pkgs; });
+    };
+}
diff --git a/notes.adoc b/notes.adoc
index 4fb37a6..eb401a7 100644
--- a/notes.adoc
+++ b/notes.adoc
@@ -93,3 +93,13 @@ PHP version 8.4.11 (/nix/store/s4kv9bzqawhqcyjg9xm2hji3jap6d6kd-php-with-extensi
 nix-shell --run "phpactor --version"
 
 Phpactor 2025.07.25.0
+
+---
+
+inputs = {
+  nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+};
+
+is the same as 
+
+inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";