chore: add nix

default.nix

@@ -0,0 +1,37 @@
+{
+  rust-overlay ? import (import ./nix/flake-parse.nix "rust-overlay"),
+  pkgs ? import (import ./nix/flake-parse.nix "nixpkgs") {
+    system = builtins.currentSystem;
+    overlays = [ rust-overlay ];
+  },
+}:
+let
+  rustToolchain = pkgs.rust-bin.stable.latest.default.override {
+    extensions = [
+      "rust-analyzer"
+      "rust-src"
+      "llvm-tools"
+    ];
+  };
+in
+{
+  shell = import ./nix/shell.nix {
+    inherit pkgs rustToolchain;
+  };
+
+  formatter = import ./nix/formatter.nix { inherit pkgs rustToolchain; };
+
+  packages =
+    let
+      rustPlatform = pkgs.makeRustPlatform {
+        cargo = rustToolchain;
+        rustc = rustToolchain;
+      };
+    in
+    rec {
+      default = pkgs.callPackage ./nix/package.nix {
+        inherit rustPlatform;
+      };
+      sessiond-seat = default;
+    };
+}