{
  description = "SymClaw — symbolic mathematics engine";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    rust-overlay = {
      url = "github:oxalica/rust-overlay";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    crane.url = "github:ipetkov/crane";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, rust-overlay, crane, flake-utils }:
    let
      supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
      meta = {
        description = "SymClaw symbolic mathematics engine";
        homepage = "https://github.com/symclaw/symclaw";
        license = with nixpkgs.lib; [ licenses.mit licenses.asl20 ];
      };
    in
    flake-utils.lib.eachSystem supportedSystems (system:
      let
        overlays = [ (import rust-overlay) ];
        pkgs = import nixpkgs { inherit system overlays; };

        rustToolchain = pkgs.rust-bin.stable."1.93.0".default.override {
          extensions = [ "rustfmt" "clippy" "rust-src" ];
          targets = [ "wasm32-unknown-unknown" ];
        };

        craneLib = (crane.mkLib pkgs).overrideToolchain rustToolchain;

        src = pkgs.lib.cleanSourceWith {
          src = craneLib.path ./.;
          filter = path: type:
            (craneLib.filterCargoSources path type)
            || (builtins.match ".*\.md$" path != null);
        };

        commonArgs = {
          inherit src;
          strictDeps = true;
          buildInputs = [ pkgs.openssl ]
            ++ pkgs.lib.optionals pkgs.stdenv.isDarwin [
              pkgs.darwin.apple_sdk.frameworks.Security
              pkgs.darwin.apple_sdk.frameworks.SystemConfiguration
              pkgs.libiconv
            ];
          nativeBuildInputs = [ pkgs.pkg-config ];
        };

        cargoArtifacts = craneLib.buildDepsOnly commonArgs;

        buildCrate = name: craneLib.buildPackage (commonArgs // {
          inherit cargoArtifacts meta;
          cargoExtraArgs = "-p ${name}";
        });

      in {
        packages = {
          symclaw-cli = buildCrate "symclaw-cli";
          symclaw-skill = buildCrate "symclaw-skill";

          symclaw-wasm = craneLib.buildPackage (commonArgs // {
            inherit cargoArtifacts meta;
            cargoExtraArgs = "-p symclaw-wasm";
            CARGO_BUILD_TARGET = "wasm32-unknown-unknown";
            buildInputs = [];
            nativeBuildInputs = [];
            doCheck = false;
            installPhaseCommand = ''
              mkdir -p $out/lib
              cp target/wasm32-unknown-unknown/release/*.wasm $out/lib/ 2>/dev/null || true
            '';
          });

          default = self.packages.${system}.symclaw-cli;
        };

        checks = {
          workspace-test = craneLib.cargoTest (commonArgs // {
            inherit cargoArtifacts;
          });

          workspace-clippy = craneLib.cargoClippy (commonArgs // {
            inherit cargoArtifacts;
            cargoClippyExtraArgs = "--all-targets -- -D warnings";
          });

          workspace-fmt = craneLib.cargoFmt {
            inherit src;
          };
        };

        devShells.default = craneLib.devShell {
          checks = self.checks.${system};
          packages = with pkgs; [
            cargo-watch
            cargo-expand
            wasm-bindgen-cli
            wasm-pack
            pkg-config
            openssl
          ];
        };
      }
    ) // {
      nixosModules.symclaw = { config, lib, pkgs, ... }: {
        options.services.symclaw = {
          enable = lib.mkEnableOption "SymClaw symbolic math engine";
          port = lib.mkOption {
            type = lib.types.port;
            default = 18789;
            description = "Port for the SymClaw skill service";
          };
          engineMode = lib.mkOption {
            type = lib.types.enum [ "native" "wasm" ];
            default = "native";
            description = "Execution engine mode";
          };
          logLevel = lib.mkOption {
            type = lib.types.str;
            default = "info";
            description = "RUST_LOG level";
          };
        };

        config = lib.mkIf config.services.symclaw.enable {
          systemd.services.symclaw = {
            description = "SymClaw Symbolic Mathematics Engine";
            wantedBy = [ "multi-user.target" ];
            serviceConfig = {
              ExecStart = "${self.packages.${pkgs.system}.symclaw-skill}/bin/symclaw-skill";
              Restart = "on-failure";
              DynamicUser = true;
              Environment = [
                "RUST_LOG=${config.services.symclaw.logLevel}"
                "SYMCLAW_PORT=${toString config.services.symclaw.port}"
                "SYMCLAW_ENGINE=${config.services.symclaw.engineMode}"
              ];
            };
          };
        };
      };

      overlays.default = final: prev: {
        symclaw-cli = self.packages.${final.system}.symclaw-cli;
        symclaw-skill = self.packages.${final.system}.symclaw-skill;
        symclaw-wasm = self.packages.${final.system}.symclaw-wasm;
      };
    };
}