diff --git a/arnau/posv/flake.lock b/arnau/posv/flake.lock
new file mode 100644
index 0000000..3914468
--- /dev/null
+++ b/arnau/posv/flake.lock
@@ -0,0 +1,42 @@
+{
+  "nodes": {
+    "bscpkgs": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      },
+      "locked": {
+        "lastModified": 1758895966,
+        "narHash": "sha256-L8DeK85bI7Ry4YfqO/5svwO0nVZLN7lviWalIGtKr7g=",
+        "ref": "refs/heads/master",
+        "rev": "2ffdd53d86157ea83a867b544e7bedf89797b72b",
+        "revCount": 985,
+        "type": "git",
+        "url": "https://jungle.bsc.es/git/rarias/bscpkgs"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://jungle.bsc.es/git/rarias/bscpkgs"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1752436162,
+        "narHash": "sha256-Kt1UIPi7kZqkSc5HVj6UY5YLHHEzPBkgpNUByuyxtlw=",
+        "path": "/nix/store/zk8v61cpk1wprp9ld5ayc1g5fq4pdkwv-source",
+        "rev": "dfcd5b901dbab46c9c6e80b265648481aafb01f8",
+        "type": "path"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "bscpkgs": "bscpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/arnau/posv/flake.nix b/arnau/posv/flake.nix
new file mode 100644
index 0000000..bf53a62
--- /dev/null
+++ b/arnau/posv/flake.nix
@@ -0,0 +1,47 @@
+{
+  # Fetch the list of packages for BSC
+  inputs.bscpkgs.url = "git+https://jungle.bsc.es/git/rarias/bscpkgs";
+
+  outputs = { self, bscpkgs }:  
+  let
+    customOverlay = final: prev: {
+      # Disable GIL in python
+      python314 = prev.python314.override {
+        enableGIL = false;
+      };
+      # Use a custom nOS-V commit
+      nosv = prev.nosv.override {
+        useGit = true;
+        gitBranch = "nosv_join";
+        gitCommit = "33130d271a59d0794545e4a2a597a56951e428aa";
+        gitUrl = "ssh://git@gitlab-internal.bsc.es/acinca/nos-v.git";
+      };
+    };
+    pkgs = import bscpkgs.inputs.nixpkgs {
+      system = "x86_64-linux";
+      overlays = [
+        # Add our BSC packages
+        bscpkgs.bscOverlay
+        # And our changes above on top
+        customOverlay
+      ];
+    };
+  in {
+    devShells.x86_64-linux.default = pkgs.mkShell {
+      pname = "devshell";
+      # Set the NOSV_HOME to point to the current nosv package
+      NOSV_HOME = pkgs.nosv;
+
+      # These will be included in the environment with `nix develop`.
+      buildInputs = with pkgs; [
+        # Add python to the develop shell, with setuptools included
+        (python314.withPackages (python-pkgs: with python-pkgs; [
+          setuptools
+        ]))
+
+        # Extra packages
+        gcc cowsay nosv
+      ];
+    };
+  };
+}