{
  description = "nbd — CLI tool for managing work tickets, targeted at agent workflows";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    rust-overlay = {
      url = "github:oxalica/rust-overlay";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs =
    {
      self,
      nixpkgs,
      rust-overlay,
    }:
    let
      systems = [
        "x86_64-linux"
        "aarch64-linux"
        "x86_64-darwin"
        "aarch64-darwin"
      ];

      forAllSystems =
        f:
        nixpkgs.lib.genAttrs systems (
          system:
          f {
            inherit system;
            pkgs = import nixpkgs {
              inherit system;
              overlays = [ rust-overlay.overlays.default ];
            };
          }
        );
    in
    {
      packages = forAllSystems (
        { pkgs, system }:
        {
          # The nbd CLI package, built with rustPlatform.buildRustPackage.
          nbd = pkgs.rustPlatform.buildRustPackage {
            pname = "nbd";
            version = "0.1.0";

            src = ./.;

            cargoLock = {
              lockFile = ./Cargo.lock;
            };

            meta = {
              description = "CLI tool for managing work tickets, targeted at agent workflows";
              license = with pkgs.lib.licenses; [
                asl20
                mit
              ];
              mainProgram = "nbd";
            };
          };

          # Make nbd the default package so `nix build` works without specifying an attribute.
          default = self.packages.${system}.nbd;
        }
      );

      apps = forAllSystems (
        { system, ... }:
        {
          # Run nbd directly with `nix run .#nbd`.
          nbd = {
            type = "app";
            program = "${self.packages.${system}.nbd}/bin/nbd";
          };

          # Make nbd the default app so `nix run` works without specifying an attribute.
          default = self.apps.${system}.nbd;
        }
      );

      devShells = forAllSystems (
        { pkgs, system }:
        {
          # Development shell with stable Rust toolchain and nbd binary.
          default = pkgs.mkShell {
            packages = [
              # Stable Rust toolchain: compiler, cargo, rustfmt, clippy.
              pkgs.rust-bin.stable.latest.default
              # The built nbd binary, available as `nbd` in the shell.
              self.packages.${system}.nbd
            ];
          };
        }
      );
    };
}