diff --git a/README.md b/README.md
index fa76d76..5bc0d3d 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,4 @@
 # lsfg-vk-flake
 WIP! Nix flake to build the library for using Lossless Scaling's frame generation on Linux
+
+initially broken due to various challenges with the LLVM tools in NixOS
diff --git a/default.nix b/default.nix
new file mode 100644
index 0000000..a45ac11
--- /dev/null
+++ b/default.nix
@@ -0,0 +1,85 @@
+{ lib
+, fetchFromGitHub
+, replaceVars
+, srcOnly
+, cmake
+, meson
+, ninja
+, SDL2
+, glslang
+#, glfw
+, dxvk_2
+, vulkan-headers
+, vulkan-loader
+, pkg-config
+, llvmPackages
+#, overrideCC # lto
+}: let
+
+  peparse-git = fetchFromGitHub {
+    owner = "trailofbits";
+    repo = "pe-parse";
+    rev = "v2.1.1";
+    hash = "sha256-WuG/OmzrXoH5O7+sSIdUVZP0aS63nuJwHgQfn12Q5xk=";
+    fetchSubmodules = true;
+  };
+
+  dxvk-git = srcOnly (dxvk_2.overrideAttrs (old: {
+    src = fetchFromGitHub {
+      owner = "doitsujin";
+      repo = "dxvk";
+      rev = "v2.6.2";
+      hash = "sha256-nZEi9WYhpI0WaeguoZMV4nt+nfaErvgz5RNDyyZYCJA=";
+      fetchSubmodules = true;
+    };
+  }));
+
+  # stdenv_lto = overrideCC llvmPackages.stdenv (llvmPackages.stdenv.cc.override {
+  #   inherit (llvmPackages) bintools;
+  # });
+  # this causes problems with dxvk-git which does not like llvm's ar...
+
+in llvmPackages.stdenv.mkDerivation {
+  pname = "lsfg-vk";
+  version = "0.0.31";
+
+  src = ./.;
+
+  # we need to unvendor dxvk and pe-parse which would normally be downloaded from git during buildtime in the cmakefiles
+  patches = [
+    (replaceVars ./no-download.patch {
+      dxvk-git = dxvk-git;
+      peparse-git = peparse-git;
+    })
+  ];
+
+  #cmakeFlags = [
+    #"-DCMAKE_BUILD_TYPE=Release"
+    #"-DCMAKE_INSTALL_PREFIX=${placeholder "out"}"
+    #"-DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON" # LTO
+  #];
+
+  nativeBuildInputs = [
+    #llvmPackages.clang-tools # https://github.com/NixOS/nixpkgs/issues/273875
+    #llvmPackages.libcxxClang # LTO: "ar: error: the 'o' modifier is only applicable to the 'x' operation"
+    #llvmPackages.bintools # LTO: "RANLIB-NOTFOUND, AR-NOTFOUND"
+    cmake
+    meson
+    ninja
+    pkg-config
+  ];
+
+  buildInputs = [
+    dxvk-git
+    SDL2
+    glslang
+    vulkan-headers
+    vulkan-loader
+  ];
+
+  meta = with lib; {
+    homepage = "https://github.com/PancakeTAS/lsfg-vk/";
+    license = licenses.mit;
+    platforms = platforms.linux;
+  };
+}
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..a63de06
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1751792365,
+        "narHash": "sha256-J1kI6oAj25IG4EdVlg2hQz8NZTBNYvIS0l4wpr9KcUo=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "1fd8bada0b6117e6c7eb54aad5813023eed37ccb",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..7e14bb7
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,10 @@
+{
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs = { nixpkgs, ... }: let
+    system = "x86_64-linux";
+    pkgs = import nixpkgs { inherit system; };
+  in {
+    packages.${system}.default = pkgs.callPackage ./default.nix {};
+  };
+}
diff --git a/no-download.patch b/no-download.patch
new file mode 100644
index 0000000..5e5b7ac
--- /dev/null
+++ b/no-download.patch
@@ -0,0 +1,28 @@
+diff --git a/cmake/FetchDXVK.cmake b/cmake/FetchDXVK.cmake
+index f84de82..bbe9f73 100644
+--- a/cmake/FetchDXVK.cmake
++++ b/cmake/FetchDXVK.cmake
+@@ -9,8 +9,7 @@ else()
+ endif()
+ 
+ ExternalProject_Add(dxvk_git
+-    GIT_REPOSITORY "https://github.com/doitsujin/dxvk"
+-    GIT_TAG "v2.6.2"
++    URL file://@dxvk-git@
+     UPDATE_DISCONNECTED true
+     USES_TERMINAL_CONFIGURE true
+     USES_TERMINAL_BUILD true
+diff --git a/cmake/FetchPeParse.cmake b/cmake/FetchPeParse.cmake
+index df7879b..31a4b87 100644
+--- a/cmake/FetchPeParse.cmake
++++ b/cmake/FetchPeParse.cmake
+@@ -1,8 +1,7 @@
+ include(ExternalProject)
+ 
+ ExternalProject_Add(peparse_git
+-    GIT_REPOSITORY "https://github.com/trailofbits/pe-parse"
+-    GIT_TAG "v2.1.1"
++    URL file://@peparse-git@
+     UPDATE_DISCONNECTED true
+     USES_TERMINAL_CONFIGURE true
+     USES_TERMINAL_BUILD true