diff --git a/README.en.md b/README.en.md
index 8a58512..c561b0c 100644
--- a/README.en.md
+++ b/README.en.md
@@ -104,6 +104,21 @@ proxy for Claude/npm, create `~/.config/kadr/claude-env.json`:
 { "env": { "HTTPS_PROXY": "http://127.0.0.1:1080", "NO_PROXY": "127.0.0.1,localhost" } }
 ```
 
+## NixOS
+
+On NixOS (tested on Niri/Wayland), a plain `npm install`/`npm run dev` can
+fail or render a blank window because of a few platform quirks (building
+`node-pty`, no prebuilt Electron binary, Wayland/Ozone). A ready-made
+`flake.nix` devShell handles this:
+
+```bash
+nix develop
+npm install
+npm run dev
+```
+
+See [docs/nixos.md](docs/nixos.md) for details and a non-flake fallback.
+
 ## How the AI integration works
 
 Kadr starts a local HTTP bridge into the renderer and hands Claude an MCP
diff --git a/README.md b/README.md
index 245a3a6..a24d1ee 100644
--- a/README.md
+++ b/README.md
@@ -107,6 +107,21 @@ Claude/npm нужен прокси — создайте `~/.config/kadr/claude-e
 { "env": { "HTTPS_PROXY": "http://127.0.0.1:1080", "NO_PROXY": "127.0.0.1,localhost" } }
 ```
 
+## NixOS
+
+На NixOS (проверено на Niri/Wayland) `npm install`/`npm run dev` из коробки
+может упасть или показать пустой экран из-за нескольких платформенных
+особенностей (сборка `node-pty`, отсутствие prebuilt-бинарника Electron,
+Wayland/Ozone). Есть `flake.nix` с готовым `devShell`:
+
+```bash
+nix develop
+npm install
+npm run dev
+```
+
+Подробности и вариант без флейков — в [docs/nixos.md](docs/nixos.md).
+
 ## Как устроена ИИ-интеграция
 
 Kadr поднимает локальный мост в рендерер и отдаёт Claude MCP-сервер с
diff --git a/docs/nixos.md b/docs/nixos.md
new file mode 100644
index 0000000..97725be
--- /dev/null
+++ b/docs/nixos.md
@@ -0,0 +1,110 @@
+# Running Kadr on NixOS / Запуск Kadr на NixOS
+
+<details open>
+<summary><b>English</b></summary>
+
+## Quick start (with flake)
+
+```bash
+nix develop
+npm install
+npm run dev
+```
+
+The devShell provides `gcc`/`make`/`python3` (needed to build the native
+`node-pty` dependency), `electron`, and `ffmpeg`, and automatically:
+
+- forces X11/XWayland via `ELECTRON_OZONE_PLATFORM_HINT=x11` (native
+  Wayland/Ozone can crash or render a blank window depending on your
+  compositor),
+- links `node_modules/electron/dist/electron` to the nixpkgs Electron
+  binary, since the npm `electron` package's binary download doesn't work
+  on NixOS's non-FHS filesystem.
+
+## Without the flake
+
+If you don't want to use flakes, run once per shell session:
+
+```bash
+nix-shell -p gcc gnumake python3 --run "npm install"
+
+export ELECTRON_OZONE_PLATFORM_HINT=x11
+export XDG_SESSION_TYPE=x11
+unset WAYLAND_DISPLAY
+
+nix-shell -p electron --run '
+  mkdir -p node_modules/electron/dist
+  printf "electron" > node_modules/electron/path.txt
+  ln -sf $(which electron) node_modules/electron/dist/electron
+  npm run dev
+'
+```
+
+## Known-good config
+
+These fixes live in the app code (not NixOS-specific), but are worth
+knowing about if you hit similar symptoms elsewhere:
+
+- `electron.vite.config.ts` pins the renderer dev server to
+  `host: '127.0.0.1'` to avoid an intermittent `ERR_NETWORK_CHANGED` on
+  systems with IPv6 disabled or misconfigured.
+- `electron/preload.ts` assigns `window.kadr` unconditionally (guarded by
+  `Object.keys(api)`) so Vite's bundler can't tree-shake the whole API
+  object away when `contextIsolation: false` is a compile-time constant.
+
+</details>
+
+<details>
+<summary><b>Русский</b></summary>
+
+## Быстрый старт (с флейком)
+
+```bash
+nix develop
+npm install
+npm run dev
+```
+
+DevShell предоставляет `gcc`/`make`/`python3` (нужны для сборки нативной
+зависимости `node-pty`), `electron` и `ffmpeg`, а также автоматически:
+
+- принудительно включает X11/XWayland через `ELECTRON_OZONE_PLATFORM_HINT=x11`
+  (нативный Wayland/Ozone может падать или рисовать пустое окно в
+  зависимости от вашего компоузера),
+- линкует `node_modules/electron/dist/electron` на бинарник Electron из
+  nixpkgs, так как загрузка бинарника npm-пакетом `electron` не работает
+  на не-FHS файловой системе NixOS.
+
+## Без флейка
+
+Если не хотите использовать флейки, выполняйте один раз на сессию шелла:
+
+```bash
+nix-shell -p gcc gnumake python3 --run "npm install"
+
+export ELECTRON_OZONE_PLATFORM_HINT=x11
+export XDG_SESSION_TYPE=x11
+unset WAYLAND_DISPLAY
+
+nix-shell -p electron --run '
+  mkdir -p node_modules/electron/dist
+  printf "electron" > node_modules/electron/path.txt
+  ln -sf $(which electron) node_modules/electron/dist/electron
+  npm run dev
+'
+```
+
+## Известные фиксы в конфиге
+
+Эти фиксы находятся в коде приложения (не специфичны для NixOS), но
+полезно о них знать при похожих симптомах в других окружениях:
+
+- `electron.vite.config.ts` закрепляет dev-сервер рендерера на
+  `host: '127.0.0.1'`, что убирает периодический `ERR_NETWORK_CHANGED` на
+  системах с отключённым или неправильно настроенным IPv6.
+- `electron/preload.ts` присваивает `window.kadr` безусловно (под защитой
+  `Object.keys(api)`), чтобы бандлер Vite не мог вытряхнуть весь объект
+  API tree-shaking'ом, когда `contextIsolation: false` известна на этапе
+  компиляции.
+
+</details>
diff --git a/electron.vite.config.ts b/electron.vite.config.ts
index f32c57f..7e80a3d 100644
--- a/electron.vite.config.ts
+++ b/electron.vite.config.ts
@@ -26,6 +26,10 @@ export default defineConfig({
   },
   renderer: {
     root: '.',
+    server: {
+      host: '127.0.0.1',
+      port: 5173
+    },
     build: {
       outDir: 'out/renderer',
       rollupOptions: { input: resolve(__dirname, 'index.html') }
diff --git a/electron/main.ts b/electron/main.ts
index a6d2b34..f6d6302 100644
--- a/electron/main.ts
+++ b/electron/main.ts
@@ -88,11 +88,14 @@ function createWindow() {
       app.exit(1)
     }
   })
-  if (process.env.ELECTRON_RENDERER_URL) {
-    win.loadURL(process.env.ELECTRON_RENDERER_URL)
-  } else {
-    win.loadFile(join(__dirname, '../renderer/index.html'))
-  }
+  setTimeout(() => {
+    if (process.env.ELECTRON_RENDERER_URL) {
+      const url = process.env.ELECTRON_RENDERER_URL.replace('localhost', '127.0.0.1');
+      win.loadURL(url)
+    } else {
+      win.loadFile(join(__dirname, '../renderer/index.html'))
+    }
+  }, 1500);
 }
 
 /**
diff --git a/electron/preload.ts b/electron/preload.ts
index c009d4d..727c747 100644
--- a/electron/preload.ts
+++ b/electron/preload.ts
@@ -156,8 +156,13 @@ const api: KadrApi = {
   }
 }
 
+// Side-effect guard: prevent Vite from tree-shaking the api object
+// because the renderer accesses these methods at runtime via window.kadr
+void Object.keys(api)
+
 // contextIsolation is off (see main.ts: export frames pass by reference),
 // so the api object lands on the shared window directly; the bridge branch
 // keeps working if isolation is ever re-enabled.
+Object.defineProperty(globalThis, 'kadr', { value: api, writable: true, configurable: true })
 if (process.contextIsolated) contextBridge.exposeInMainWorld('kadr', api)
-else (globalThis as unknown as { kadr: KadrApi }).kadr = api
+console.log('[preload] kadr api keys:', Object.keys(api))
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..45648b0
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,53 @@
+{
+  description = "Kadr dev environment (NixOS)";
+
+  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; };
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          buildInputs = [
+            pkgs.nodejs_22
+            pkgs.electron
+            pkgs.ffmpeg
+            pkgs.gcc
+            pkgs.gnumake
+            pkgs.python3
+            pkgs.pkg-config
+          ];
+
+          shellHook = ''
+            # --- Force X11/XWayland: native Wayland/Ozone crashes or renders
+            # a blank window under some compositors (observed on Niri). ---
+            export ELECTRON_OZONE_PLATFORM_HINT=x11
+            export XDG_SESSION_TYPE=x11
+            unset WAYLAND_DISPLAY
+            unset NIRI_SOCKET
+
+            export KADR_FFMPEG="${pkgs.ffmpeg}/bin/ffmpeg"
+            export KADR_FFPROBE="${pkgs.ffmpeg}/bin/ffprobe"
+
+            # --- npm's "electron" package expects to download a prebuilt
+            # binary into node_modules/electron/dist/, which fails on
+            # NixOS's non-FHS filesystem. Point it at the nixpkgs build
+            # instead, the same way `electron` upstream supports via
+            # path.txt + dist/<name>. ---
+            if [ -d node_modules/electron ] && [ ! -f node_modules/electron/dist/electron ]; then
+              mkdir -p node_modules/electron/dist
+              printf "electron" > node_modules/electron/path.txt
+              ln -sf "${pkgs.electron}/bin/electron" node_modules/electron/dist/electron
+              echo "[flake] linked node_modules/electron/dist/electron -> nixpkgs electron"
+            fi
+
+            echo "[flake] Kadr devShell ready. Run: npm install && npm run dev"
+          '';
+        };
+      });
+}