diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..3550a30
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..538ed87
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,11 @@
+dev/kimai/
+dev/.mariadb-data/
+dev/.mariadb.sock
+dev/.mariadb.sock.lock
+dev/.mariadb.pid
+node_modules/
+vendor/
+.direnv/
+result
+*.js.map
+dist/
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..ad59db8
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1775579569,
+        "narHash": "sha256-/m3yyS/EnXqoPGBJYVy4jTOsirdgsEZ3JdN2gGkBr14=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "dfd9566f82a6e1d55c30f861879186440614696e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-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..823c3e7
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,36 @@
+{
+  description = "Kimai Heatmap Plugin dev environment";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  };
+
+  outputs = { self, nixpkgs }:
+    let
+      system = "x86_64-linux";
+      pkgs = nixpkgs.legacyPackages.${system};
+      php = pkgs.php82.buildEnv {
+        extensions = { enabled, all }: enabled ++ (with all; [ xsl pdo_mysql ]);
+      };
+    in
+    {
+      devShells.${system}.default = pkgs.mkShell {
+        buildInputs = [
+          php
+          pkgs.php82Packages.composer
+          pkgs.nodejs_22
+          pkgs.mariadb
+          pkgs.symfony-cli
+          pkgs.process-compose
+        ];
+
+        shellHook = ''
+          echo ""
+          echo "Kimai Heatmap Plugin - Dev Environment"
+          echo "  First-time setup:  bash dev/setup.sh"
+          echo "  Start dev stack:   process-compose -f dev/process-compose.yaml up"
+          echo ""
+        '';
+      };
+    };
+}