{
  description = "Development environment for impro and impro-sample-plugin";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs { inherit system; config.allowUnfree = true;};

        nodeVersion = pkgs.nodejs_24.version;

        # Runtime shared libraries for the prebuilt `canvas` npm package
        # (used by tests/unit/specs/components/image-cropper.test.js).
        canvasRuntimeLibs = with pkgs; [
          cairo
          pango
          libjpeg
          giflib
          librsvg
          pixman
          util-linux # provides libuuid.so.1
        ];
      in
      {
        devShells.default = pkgs.mkShell {
          name = "impro-dev";

          packages = with pkgs; [
            # Runtime + package manager
            nodejs_24
            # Language servers (LSP) and formatters
            typescript-language-server
            typescript
            vscode-langservers-extracted
            prettier
            # End-to-end test driver + bundled browsers
            playwright-driver
            # VCS
            git
            claude-code # make sure we have latest version
            # Build toolchain for rebuilding `canvas` from source against
            # the libs below (nixpkgs' cairo isn't ABI-compatible with
            # canvas's prebuilt binary, so the download-a-binary path
            # from `npm install` doesn't work here): run
            # `npm rebuild canvas --build-from-source` once after installing.
            pkg-config
            python3
            gnumake
          ] ++ canvasRuntimeLibs;

          buildInputs = canvasRuntimeLibs;

          shellHook = ''
            echo ""
            echo "impro dev shell (node ${nodeVersion})"
            echo "  impro:               cd impro && npm install && npm run start"
            echo "  impro-sample-plugin: cd impro-sample-plugin && npm install && npm run watch"
            echo "  unit tests:          npm run test:unit      (in impro/)"
            echo "  e2e tests:           npm run test:e2e       (in impro/)"
            echo "  debug:               node --inspect-brk    (attach via chrome://inspect or your editor)"
            echo ""
            # Point Playwright at the nix-installed browser bundle so it does not
            # try to re-download into ~/.cache/ms-playwright on every run.
            export PLAYWRIGHT_BROWSERS_PATH=${pkgs.playwright-driver.browsers}
            # The prebuilt `canvas` npm package dlopen()s these at runtime;
            # nix doesn't put them on the loader path by default.
            export LD_LIBRARY_PATH=${pkgs.lib.makeLibraryPath canvasRuntimeLibs}''${LD_LIBRARY_PATH:+:}$LD_LIBRARY_PATH
          '';
        };
      }
    );
}