{
  description = "FeDIY: a federated ActivityPub DIY platform built in Rust";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    fenix = {
      url = "github:nix-community/fenix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs =
    inputs@{ self, ... }:
    let
      supportedSystems = [
        "x86_64-linux"
        "aarch64-linux"
        "x86_64-darwin"
        "aarch64-darwin"
      ];
      forEachSupportedSystem =
        f:
        inputs.nixpkgs.lib.genAttrs supportedSystems (
          system:
          f {
            pkgs = import inputs.nixpkgs {
              inherit system;
              overlays = [
                inputs.self.overlays.default
              ];
            };
          }
        );
    in
    {
      templates = {
        default = {
          path = ./.;
          description = "FeDIY Rust development environment and package outputs for Nix and non-Nix contributors";
        };
      };

      overlays.default = _final: prev: {
        rustToolchain =
          with inputs.fenix.packages.${prev.stdenv.hostPlatform.system};
          combine (
            with stable;
            [
              clippy
              rustc
              cargo
              rustfmt
              rust-src
            ]
          );
      };

      devShells = forEachSupportedSystem (
        { pkgs }:
        {
          default = pkgs.mkShell {
            packages =
              with pkgs;
              [
                # Rust toolchain (managed by fenix overlay)
                rustToolchain
                rust-analyzer
                # Build essentials
                git
                gnumake
                openssl
                pkg-config
                # Local database tooling
                postgresql
                # Localization tooling
                gettext
                # Browser and accessibility testing
                chromium
                playwright
                # Cargo productivity tools
                cargo-deny
                cargo-edit
                cargo-watch
                # Code quality
                pre-commit
                # Packaging
                flatpak-builder
              ]
              ++ lib.optionals pkgs.stdenv.isLinux [
                # OCI/container tooling (Linux host only)
                podman
                podman-compose
                buildah
              ];

            env = {
              # Required by rust-analyzer
              RUST_SRC_PATH = "${pkgs.rustToolchain}/lib/rustlib/src/rust/library";
            };

            shellHook = ''
              # Initialize git repository if not already present
              if [ ! -d .git ]; then
                git init
                echo "✓ Initialized git repository"
              fi

              echo "[FeDIY] Welcome to the dev shell!"
              echo "If you're new to Nix: this shell gives you the exact tools this repo expects."
              echo "Start with 'cargo build'. Use 'nix run .#dev-helper' for a quick tool summary."
              echo "Tools: cargo, rustc, clippy, rustfmt, rust-analyzer, flatpak-builder, psql, gettext, chromium, playwright"
              echo "Packaging note: the shell is intentionally reviewed and trimmed as the roadmap changes."
              if command -v podman >/dev/null 2>&1; then
                echo "OCI tools: podman, podman-compose, buildah"
              fi
              echo "Run 'cargo build' to build, 'cargo test' to test, or 'make flatpak-build' for Flatpak."
              echo "See README.md for usage."
            '';
          };
        }
      );

      packages = forEachSupportedSystem (
        { pkgs }:
        {
          # Build the FeDIY Cargo project
          default = pkgs.rustPlatform.buildRustPackage {
            pname = "fediy";
            version = "0.1.0";
            src = ./.;
            cargoLock.lockFile = ./Cargo.lock;
            meta.mainProgram = "fediy";
          };

          devHelper = pkgs.writeShellScriptBin "dev-helper" ''
            echo "=== FeDIY dev shell tools ==="
            echo "Build + Rust"
            command -v cargo >/dev/null 2>&1 && echo "  cargo: $(cargo --version)" || echo "  cargo: not found"
            command -v rustc >/dev/null 2>&1 && echo "  rustc: $(rustc --version)" || echo "  rustc: not found"
            command -v rust-analyzer >/dev/null 2>&1 && echo "  rust-analyzer: $(rust-analyzer --version)" || echo "  rust-analyzer: not found"
            echo "Testing + quality"
            command -v pre-commit >/dev/null 2>&1 && echo "  pre-commit: $(pre-commit --version)" || echo "  pre-commit: not found"
            command -v flatpak-builder >/dev/null 2>&1 && echo "  flatpak-builder: $(flatpak-builder --version)" || echo "  flatpak-builder: not found"
            echo "Data + localization"
            command -v psql >/dev/null 2>&1 && echo "  psql: $(psql --version)" || echo "  psql: not found"
            command -v gettext >/dev/null 2>&1 && echo "  gettext: $(gettext --version | head -n 1)" || echo "  gettext: not found"
            echo "Accessibility + browser checks"
            command -v chromium >/dev/null 2>&1 && echo "  chromium: $(chromium --version)" || echo "  chromium: not found"
            command -v playwright >/dev/null 2>&1 && echo "  playwright: $(playwright --version)" || echo "  playwright: not found"
            if command -v podman >/dev/null 2>&1; then
              echo "Container tooling"
              echo "  podman: $(podman --version)"
              command -v podman-compose >/dev/null 2>&1 && echo "  podman-compose: $(podman-compose --version)" || echo "  podman-compose: not found"
              command -v buildah >/dev/null 2>&1 && echo "  buildah: $(buildah --version)" || echo "  buildah: not found"
            fi
          '';
        }
      );

      apps = forEachSupportedSystem (
        { pkgs }:
        {
          default = {
            type = "app";
            program = pkgs.lib.getExe self.packages.${pkgs.stdenv.hostPlatform.system}.default;
          };
          dev-helper = {
            type = "app";
            program = pkgs.lib.getExe self.packages.${pkgs.stdenv.hostPlatform.system}.devHelper;
          };
        }
      );
    };
}