add nix support with flake

flake.lock

@@ -0,0 +1,62 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1741708242,
+        "narHash": "sha256-cNRqdQD4sZpN7JLqxVOze4+WsWTmv2DGH0wNCOVwrWc=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "b62d2a95c72fb068aecd374a7262b37ed92df82b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1741513245,
+        "narHash": "sha256-7rTAMNTY1xoBwz0h7ZMtEcd8LELk9R5TzBPoHuhNSCk=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "e3e32b642a31e6714ec1b712de8c91a3352ce7e1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "pyproject-nix": {
+      "inputs": {
+        "nixpkgs": "nixpkgs_2"
+      },
+      "locked": {
+        "lastModified": 1741648141,
+        "narHash": "sha256-jQEZCSCgm60NGmBg3JPu290DDhNVI1GVVEd0P8VCnME=",
+        "owner": "pyproject-nix",
+        "repo": "pyproject.nix",
+        "rev": "7747e5a058245c7abe033a798f818f0572d8e155",
+        "type": "github"
+      },
+      "original": {
+        "owner": "pyproject-nix",
+        "repo": "pyproject.nix",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs",
+        "pyproject-nix": "pyproject-nix"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,37 @@
+{
+  description = "ComfyUI with requirements.txt";
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    pyproject-nix.url = "github:pyproject-nix/pyproject.nix";
+  };
+
+  outputs = {
+    self,
+    nixpkgs,
+    pyproject-nix,
+    ...
+  } @ inputs: let
+    system = "x86_64-linux";
+    pkgs = import nixpkgs {
+      inherit system;
+      config.allowUnfree = true;
+      config.cudaSupport = true;
+    };
+    python = pkgs.python3;
+    project = pyproject-nix.lib.project.loadRequirementsTxt {
+      projectRoot = ./.;
+    };
+    pythonEnv = assert project.validators.validateVersionConstraints {inherit python;} == {}; (
+      pkgs.python3.withPackages (project.renderers.withPackages {
+        inherit python;
+      })
+    );
+  in {
+    formatter.${system} = nixpkgs.legacyPackages.${system}.alejandra;
+    devShells.${system}.default = pkgs.mkShell {
+      packages = [
+        pythonEnv
+      ];
+    };
+  };
+}

requirements.txt

@@ -18,6 +18,6 @@ psutil
 
 #non essential dependencies:
 kornia>=0.7.1
-spandrel
+# spandrel
 soundfile
 av