Use nix

flake.nix

@@ -0,0 +1,65 @@
+{
+  description = "Flake for https://github.com/n8henrie/fastcli";
+
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+  outputs =
+    { self, nixpkgs }:
+    let
+      systems = [
+        "aarch64-darwin"
+        "x86_64-darwin"
+        "x86_64-linux"
+        "aarch64-linux"
+      ];
+      eachSystem =
+        with nixpkgs.lib;
+        f: foldAttrs mergeAttrs { } (map (s: mapAttrs (_: v: { ${s} = v; }) (f s)) systems);
+    in
+    eachSystem (
+      system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+        pname = "fastcli";
+      in
+      {
+        packages = {
+          default = pkgs.python311.withPackages (_: [ self.packages.${system}.${pname} ]);
+          ${pname} = pkgs.callPackage (
+            { lib, python3Packages }:
+            python3Packages.buildPythonPackage {
+              inherit pname;
+              version = builtins.elemAt (lib.splitString "\"" (
+                lib.findSingle (val: builtins.match "^__version__ = \".*\"$" val != null) (abort "none")
+                  (abort "multiple")
+                  (lib.splitString "\n" (builtins.readFile ./${pname}/__init__.py))
+              )) 1;
+              src = lib.cleanSource ./.;
+              pyproject = true;
+              nativeBuildInputs = with python3Packages; [ pythonRelaxDepsHook ];
+              build-system = [ python3Packages.setuptools-scm ];
+              dependencies = with python3Packages; [ aiohttp ];
+              pythonRelaxDeps = [ "aiohttp" ];
+            }
+          ) { };
+        };
+
+        devShells.${system}.default = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            python38
+            python39
+            python310
+            python311
+            (python312.withPackages (
+              ps:
+              propagatedBuildInputs
+              ++ (with ps; [
+                mypy
+                pytest
+                tox
+              ])
+            ))
+          ];
+        };
+      }
+    );
+}