Use nix-direnv flake support.

.envrc

@@ -1 +1,2 @@
-use nix
+watch_file shell.nix
+use flake

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1709703039,
+        "narHash": "sha256-6hqgQ8OK6gsMu1VtcGKBxKQInRLHtzulDo9Z5jxHEFY=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "9df3e30ce24fd28c7b3e2de0d986769db5d6225d",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,15 @@
+{
+    description = "hb-downloader";
+    inputs = {
+        nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    };
+
+    outputs = { self, nixpkgs, ... }:
+        let
+            system = "x86_64-linux";
+            pkgs = nixpkgs.legacyPackages.${system};
+        in
+        {
+            devShells.x86_64-linux.default = ( import ./shell.nix { inherit pkgs; });
+        };
+}