diff --git a/.env.windows.example b/.env.windows.example
new file mode 100644
index 00000000..9a2e19c8
--- /dev/null
+++ b/.env.windows.example
@@ -0,0 +1,18 @@
+# Local Windows signing config — copy to .env.windows (gitignored) and fill in.
+# Used by scripts/build-app-win.ps1 when running a signed local Windows build.
+# CI uses GitHub Actions Secrets with the same names — see .github/workflows/release-windows.yml.
+
+# Azure Trusted Signing — Microsoft.Trusted.Signing.Client + signtool
+AZURE_TENANT_ID=
+AZURE_CLIENT_ID=
+AZURE_CLIENT_SECRET=
+AZURE_SIGNING_ENDPOINT=https://wus2.codesigning.azure.net/
+AZURE_SIGNING_ACCOUNT=mist-code-signing
+AZURE_SIGNING_CERT_PROFILE=Mist-Windows-Signing
+
+# Optional — only needed if signtool / dlib aren't auto-discovered
+# SIGNTOOL_PATH=
+# AZURE_SIGNING_DLIB=
+
+# GitHub Releases publish (set if running build-app-win.ps1 -Publish)
+GH_TOKEN=
diff --git a/.github/workflows/release-windows.yml b/.github/workflows/release-windows.yml
new file mode 100644
index 00000000..7dd1d1ae
--- /dev/null
+++ b/.github/workflows/release-windows.yml
@@ -0,0 +1,123 @@
+name: Release (Windows)
+
+# Builds + signs + uploads the Windows installer to the GitHub Release matching
+# the app version in electron/package.json. Mac builds stay on the local
+# publish.sh flow — this workflow is Windows-only on purpose.
+#
+# Triggers:
+#   - Push a tag `v*` (e.g. v1.0.25) → full signed release build, uploaded to
+#     the release of that tag (creates it in draft if absent).
+#   - Manual dispatch (workflow_dispatch) with `publish: false` → signed build
+#     as an artifact, no release upload. Useful for smoke-tests.
+#
+# Required repository secrets (Settings → Secrets and variables → Actions):
+#   AZURE_TENANT_ID
+#   AZURE_CLIENT_ID
+#   AZURE_CLIENT_SECRET
+#   AZURE_SIGNING_ENDPOINT          e.g. https://wus2.codesigning.azure.net/
+#   AZURE_SIGNING_ACCOUNT           mist-code-signing
+#   AZURE_SIGNING_CERT_PROFILE      Mist-Windows-Signing
+
+on:
+  push:
+    tags:
+      - 'v*'
+  workflow_dispatch:
+    inputs:
+      publish:
+        description: 'Publish to GitHub Releases (otherwise artifact only)'
+        required: true
+        default: 'false'
+        type: choice
+        options:
+          - 'false'
+          - 'true'
+
+permissions:
+  contents: write
+
+jobs:
+  build-windows:
+    runs-on: windows-latest
+    timeout-minutes: 60
+
+    env:
+      AZURE_TENANT_ID:            ${{ secrets.AZURE_TENANT_ID }}
+      AZURE_CLIENT_ID:            ${{ secrets.AZURE_CLIENT_ID }}
+      AZURE_CLIENT_SECRET:        ${{ secrets.AZURE_CLIENT_SECRET }}
+      AZURE_SIGNING_ENDPOINT:     ${{ secrets.AZURE_SIGNING_ENDPOINT }}
+      AZURE_SIGNING_ACCOUNT:      ${{ secrets.AZURE_SIGNING_ACCOUNT }}
+      AZURE_SIGNING_CERT_PROFILE: ${{ secrets.AZURE_SIGNING_CERT_PROFILE }}
+      PUBLISH_INPUT:              ${{ github.event.inputs.publish }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+
+      - name: Setup Python (for building bundled python-env)
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.13'
+
+      # The signing hook calls `signtool.exe` directly. signtool ships in the
+      # Windows 10 SDK, preinstalled on windows-latest runners — we just need
+      # the dlib for Azure Trusted Signing, pulled via NuGet.
+      - name: Install Microsoft.Trusted.Signing.Client (dlib for signtool)
+        shell: pwsh
+        run: |
+          $ErrorActionPreference = 'Stop'
+          $dlibDir = Join-Path $env:GITHUB_WORKSPACE 'trusted-signing-client'
+          New-Item -ItemType Directory -Force -Path $dlibDir | Out-Null
+          nuget install Microsoft.Trusted.Signing.Client -Version 1.0.60 -OutputDirectory $dlibDir -ExcludeVersion
+          $dlib = Join-Path $dlibDir 'Microsoft.Trusted.Signing.Client\bin\x64\Azure.CodeSigning.Dlib.dll'
+          if (-not (Test-Path $dlib)) {
+            Get-ChildItem -Path $dlibDir -Recurse -Filter 'Azure.CodeSigning.Dlib.dll' | ForEach-Object { Write-Host "Found: $($_.FullName)" }
+            throw "Azure.CodeSigning.Dlib.dll not found after NuGet install"
+          }
+          "AZURE_SIGNING_DLIB=$dlib" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
+          Write-Host "AZURE_SIGNING_DLIB=$dlib"
+
+      - name: Locate signtool.exe on the runner
+        shell: pwsh
+        run: |
+          $ErrorActionPreference = 'Stop'
+          $candidates = Get-ChildItem -Path 'C:\Program Files (x86)\Windows Kits\10\bin' -Recurse -Filter 'signtool.exe' -ErrorAction SilentlyContinue `
+            | Where-Object { $_.FullName -match '\\x64\\signtool\.exe$' } `
+            | Sort-Object FullName -Descending
+          if (-not $candidates) { throw "signtool.exe not found on runner" }
+          $signtool = $candidates[0].FullName
+          "SIGNTOOL_PATH=$signtool" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
+          Write-Host "SIGNTOOL_PATH=$signtool"
+
+      - name: Build app
+        shell: pwsh
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          $ErrorActionPreference = 'Stop'
+          $shouldPublish = ($env:GITHUB_EVENT_NAME -eq 'push') -or `
+                           ($env:GITHUB_EVENT_NAME -eq 'workflow_dispatch' -and $env:PUBLISH_INPUT -eq 'true')
+          if ($shouldPublish) {
+            Write-Host "Build mode: PUBLISH"
+            pwsh -NoProfile -File scripts\build-app-win.ps1 -Publish
+          } else {
+            Write-Host "Build mode: SIGN (artifact only)"
+            pwsh -NoProfile -File scripts\build-app-win.ps1 -Sign
+          }
+          if ($LASTEXITCODE -ne 0) { throw "build-app-win.ps1 failed ($LASTEXITCODE)" }
+
+      - name: Upload artifact (non-publish runs)
+        if: github.event_name == 'workflow_dispatch' && github.event.inputs.publish != 'true'
+        uses: actions/upload-artifact@v4
+        with:
+          name: openswarm-windows-x64
+          path: |
+            electron/dist/*.exe
+            electron/dist/latest.yml
+          if-no-files-found: error
+          retention-days: 14
diff --git a/.gitignore b/.gitignore
index 2265eca5..bf70e327 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,8 @@
 .DS_Store
 .worktrees
 .env
+.env.*
+!.env*.example
 .local-stash/
 backend/data/**
 !backend/data/outputs/
diff --git a/9router/package.json b/9router/package.json
index 2e3238d5..0c86d03f 100644
--- a/9router/package.json
+++ b/9router/package.json
@@ -5,11 +5,11 @@
   "private": true,
   "scripts": {
     "dev": "next dev --webpack --port 20128",
-    "build": "NODE_ENV=production next build --webpack",
-    "start": "NODE_ENV=production next start",
+    "build": "cross-env NODE_ENV=production next build --webpack",
+    "start": "cross-env NODE_ENV=production next start",
     "dev:bun": "bun --bun next dev --webpack --port 20128",
-    "build:bun": "NODE_ENV=production bun --bun next build --webpack",
-    "start:bun": "NODE_ENV=production bun ./.next/standalone/server.js"
+    "build:bun": "cross-env NODE_ENV=production bun --bun next build --webpack",
+    "start:bun": "cross-env NODE_ENV=production bun ./.next/standalone/server.js"
   },
   "dependencies": {
     "@monaco-editor/react": "^4.7.0",
@@ -40,6 +40,7 @@
   },
   "devDependencies": {
     "@tailwindcss/postcss": "^4.1.18",
+    "cross-env": "^7.0.3",
     "eslint": "^9",
     "eslint-config-next": "16.1.6",
     "postcss": "^8.5.6",
diff --git a/backend/apps/outputs/view_builder_templates.py b/backend/apps/outputs/view_builder_templates.py
index 0aada357..8d54a0f3 100644
--- a/backend/apps/outputs/view_builder_templates.py
+++ b/backend/apps/outputs/view_builder_templates.py
@@ -4,7 +4,7 @@ import os
 
 _SKILL_PATH = os.path.join(os.path.dirname(__file__), "view_builder_skill.md")
 
-with open(_SKILL_PATH) as _f:
+with open(_SKILL_PATH, encoding="utf-8") as _f:
     VIEW_BUILDER_SKILL = _f.read()
 
 VIEW_TEMPLATE_INDEX = """\
diff --git a/backend/apps/tools_lib/tools_lib.py b/backend/apps/tools_lib/tools_lib.py
index b8063024..aac206ec 100644
--- a/backend/apps/tools_lib/tools_lib.py
+++ b/backend/apps/tools_lib/tools_lib.py
@@ -6,6 +6,7 @@ import re
 import logging
 import secrets
 import shutil
+import sys
 import time
 from contextlib import asynccontextmanager
 from typing import Any, Optional
@@ -415,24 +416,26 @@ def _resolve_command(command: str) -> str | None:
     found = shutil.which(command)
     if found:
         return found
+    # Windows binaries need an extension. shutil.which() handles PATHEXT for
+    # PATH lookups, but we manually scan _extra_bin_dirs below — replicate
+    # the suffix probing here so `uvx` finds `uvx.exe`, etc.
+    if sys.platform == "win32":
+        suffixes = [""] + os.environ.get("PATHEXT", ".COM;.EXE;.BAT;.CMD").lower().split(os.pathsep)
+    else:
+        suffixes = [""]
+    def _probe(directory: str) -> str | None:
+        for suffix in suffixes:
+            candidate = os.path.join(directory, command + suffix)
+            if os.path.isfile(candidate) and os.access(candidate, os.X_OK):
+                return candidate
+        return None
     for d in _extra_bin_dirs():
-        candidate = os.path.join(d, command)
-        if os.path.isfile(candidate) and os.access(candidate, os.X_OK):
-            return candidate
+        hit = _probe(d)
+        if hit:
+            return hit
     # Check bundled uv-bin directory (ships uv/uvx for non-dev users)
     _backend = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
-    _is_packaged = os.environ.get("OPENSWARM_PACKAGED") == "1"
-    if _is_packaged:
-        # In packaged app: <resources>/backend/uv-bin/
-        candidate = os.path.join(_backend, "uv-bin", command)
-        if os.path.isfile(candidate) and os.access(candidate, os.X_OK):
-            return candidate
-    else:
-        # In dev: backend/uv-bin/
-        candidate = os.path.join(_backend, "uv-bin", command)
-        if os.path.isfile(candidate) and os.access(candidate, os.X_OK):
-            return candidate
-    return None
+    return _probe(os.path.join(_backend, "uv-bin"))
 
 
 def _augmented_path() -> str:
@@ -552,14 +555,21 @@ def derive_mcp_config(tool: ToolDefinition) -> Optional[dict]:
         # Point uv/uvx at our bundled Python — avoids macOS CLT popup on fresh Macs
         # and avoids downloading Python at runtime
         _is_packaged = os.environ.get("OPENSWARM_PACKAGED") == "1"
+        _is_windows = sys.platform == "win32"
         if _is_packaged:
             _resources = os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))
-            _bundled_python = os.path.join(_resources, "python-env", "bin", "python3")
+            if _is_windows:
+                _bundled_python = os.path.join(_resources, "python-env", "python.exe")
+            else:
+                _bundled_python = os.path.join(_resources, "python-env", "bin", "python3")
             if os.path.exists(_bundled_python):
                 env.setdefault("UV_PYTHON", _bundled_python)
         else:
             _backend = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
-            _venv_python = os.path.join(_backend, ".venv", "bin", "python3")
+            if _is_windows:
+                _venv_python = os.path.join(_backend, ".venv", "Scripts", "python.exe")
+            else:
+                _venv_python = os.path.join(_backend, ".venv", "bin", "python3")
             if os.path.exists(_venv_python):
                 env.setdefault("UV_PYTHON", _venv_python)
 
diff --git a/backend/npm-servers/notionhq-notion-mcp-server/package.json b/backend/npm-servers/notionhq-notion-mcp-server/package.json
index f3463e9b..d1b7e7d5 100644
--- a/backend/npm-servers/notionhq-notion-mcp-server/package.json
+++ b/backend/npm-servers/notionhq-notion-mcp-server/package.json
@@ -1,7 +1,6 @@
 {
   "name": "notionhq-notion-mcp-server",
   "version": "1.0.0",
-  "description": "",
   "main": "index.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
@@ -12,5 +11,6 @@
   "type": "commonjs",
   "dependencies": {
     "@notionhq/notion-mcp-server": "^2.2.1"
-  }
+  },
+  "description": ""
 }
diff --git a/backend/npm-servers/softeria-ms-365-mcp-server/package.json b/backend/npm-servers/softeria-ms-365-mcp-server/package.json
index 23e84819..b2f7dd7f 100644
--- a/backend/npm-servers/softeria-ms-365-mcp-server/package.json
+++ b/backend/npm-servers/softeria-ms-365-mcp-server/package.json
@@ -1,7 +1,6 @@
 {
   "name": "softeria-ms-365-mcp-server",
   "version": "1.0.0",
-  "description": "",
   "main": "index.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
@@ -12,5 +11,6 @@
   "type": "commonjs",
   "dependencies": {
     "@softeria/ms-365-mcp-server": "^0.79.6"
-  }
+  },
+  "description": ""
 }
diff --git a/electron/build/icon.ico b/electron/build/icon.ico
new file mode 100644
index 00000000..18621b6e
Binary files /dev/null and b/electron/build/icon.ico differ
diff --git a/electron/build/sign-windows.js b/electron/build/sign-windows.js
new file mode 100644
index 00000000..8ac77fca
--- /dev/null
+++ b/electron/build/sign-windows.js
@@ -0,0 +1,95 @@
+// Custom Windows signing hook for electron-builder.
+// Uses Azure Trusted Signing via signtool + Microsoft.Trusted.Signing.Client dlib.
+//
+// Required env vars (set as GitHub Actions secrets and passed through to the job):
+//   AZURE_TENANT_ID                  Directory (tenant) ID of the app registration
+//   AZURE_CLIENT_ID                  Application (client) ID of the app registration
+//   AZURE_CLIENT_SECRET              Client secret value
+//   AZURE_SIGNING_ENDPOINT           e.g. https://eus.codesigning.azure.net
+//   AZURE_SIGNING_ACCOUNT            Trusted Signing account name (e.g. mist-code-signing)
+//   AZURE_SIGNING_CERT_PROFILE       Certificate profile name (created inside the account)
+//
+// Optional env vars:
+//   AZURE_SIGNING_DLIB               Absolute path to Azure.CodeSigning.Dlib.dll (default: resolved from AZURE_SIGNING_DLIB_DIR)
+//   AZURE_SIGNING_DLIB_DIR           Directory containing Azure.CodeSigning.Dlib.dll (default: ./Microsoft.Trusted.Signing.Client/bin/x64)
+//   SIGNTOOL_PATH                    Absolute path to signtool.exe (default: "signtool", relying on PATH)
+//   AZURE_TIMESTAMP_URL              Timestamp server (default: http://timestamp.acs.microsoft.com)
+//   CSC_IDENTITY_AUTO_DISCOVERY      Set to "false" to skip signing entirely (dev builds)
+
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const { execFileSync } = require('child_process');
+
+const REQUIRED_ENV = [
+  'AZURE_TENANT_ID',
+  'AZURE_CLIENT_ID',
+  'AZURE_CLIENT_SECRET',
+  'AZURE_SIGNING_ENDPOINT',
+  'AZURE_SIGNING_ACCOUNT',
+  'AZURE_SIGNING_CERT_PROFILE',
+];
+
+function resolveDlib() {
+  if (process.env.AZURE_SIGNING_DLIB) return process.env.AZURE_SIGNING_DLIB;
+  const dir = process.env.AZURE_SIGNING_DLIB_DIR
+    || path.join(process.cwd(), 'Microsoft.Trusted.Signing.Client', 'bin', 'x64');
+  return path.join(dir, 'Azure.CodeSigning.Dlib.dll');
+}
+
+exports.default = async function signWindows(configuration) {
+  const targetPath = configuration && configuration.path;
+  if (!targetPath) {
+    console.log('[sign-windows] No target path provided — skipping');
+    return;
+  }
+
+  if (process.env.CSC_IDENTITY_AUTO_DISCOVERY === 'false') {
+    console.log(`[sign-windows] CSC_IDENTITY_AUTO_DISCOVERY=false — skipping ${targetPath}`);
+    return;
+  }
+
+  const missing = REQUIRED_ENV.filter((k) => !process.env[k]);
+  if (missing.length) {
+    console.log(`[sign-windows] Skipping ${targetPath} — missing env: ${missing.join(', ')}`);
+    return;
+  }
+
+  const dlib = resolveDlib();
+  if (!fs.existsSync(dlib)) {
+    throw new Error(
+      `[sign-windows] Azure.CodeSigning.Dlib.dll not found at ${dlib}. `
+      + `Install the Microsoft.Trusted.Signing.Client NuGet package or set AZURE_SIGNING_DLIB.`,
+    );
+  }
+
+  const metadata = {
+    Endpoint: process.env.AZURE_SIGNING_ENDPOINT,
+    CodeSigningAccountName: process.env.AZURE_SIGNING_ACCOUNT,
+    CertificateProfileName: process.env.AZURE_SIGNING_CERT_PROFILE,
+    ExcludeEnvironmentCredential: 'false',
+  };
+  const metadataPath = path.join(os.tmpdir(), `ts-metadata-${process.pid}-${Date.now()}.json`);
+  fs.writeFileSync(metadataPath, JSON.stringify(metadata, null, 2));
+
+  const signtool = process.env.SIGNTOOL_PATH || 'signtool.exe';
+  const timestampUrl = process.env.AZURE_TIMESTAMP_URL || 'http://timestamp.acs.microsoft.com';
+  const args = [
+    'sign',
+    '/v',
+    '/fd', 'SHA256',
+    '/tr', timestampUrl,
+    '/td', 'SHA256',
+    '/dlib', dlib,
+    '/dmdf', metadataPath,
+    targetPath,
+  ];
+
+  try {
+    console.log(`[sign-windows] signtool ${args.join(' ')}`);
+    execFileSync(signtool, args, { stdio: 'inherit' });
+    console.log(`[sign-windows] Signed ${targetPath}`);
+  } finally {
+    try { fs.unlinkSync(metadataPath); } catch (_) { /* ignore */ }
+  }
+};
diff --git a/electron/main.js b/electron/main.js
index 32d013ac..65b376ab 100644
--- a/electron/main.js
+++ b/electron/main.js
@@ -79,7 +79,9 @@ let cachedUpdateStatus = { status: 'idle', info: null, error: null };
 
 const isPackaged = app.isPackaged;
 const isDev = process.env.ELECTRON_DEV === '1';
-const iconPath = path.join(__dirname, 'build', 'icon.png');
+const iconPath = process.platform === 'win32'
+  ? path.join(__dirname, 'build', 'icon.ico')
+  : path.join(__dirname, 'build', 'icon.png');
 
 /**
  * macOS GUI apps launched from Finder/Dock inherit a minimal PATH from launchd
@@ -164,12 +166,20 @@ function getResourcePath(...segments) {
 }
 
 function getPythonPath() {
+  // python-build-standalone layout differs by OS:
+  //   macOS / Linux: <env>/bin/python3
+  //   Windows:       <env>\python.exe   (no bin/, no python3)
   if (isPackaged) {
     const envPath = path.join(process.resourcesPath, 'python-env');
+    if (process.platform === 'win32') {
+      return path.join(envPath, 'python.exe');
+    }
     return path.join(envPath, 'bin', 'python3');
   }
-  const venvPython = path.join(__dirname, '..', 'backend', '.venv', 'bin', 'python3');
-  return venvPython;
+  if (process.platform === 'win32') {
+    return path.join(__dirname, '..', 'backend', '.venv', 'Scripts', 'python.exe');
+  }
+  return path.join(__dirname, '..', 'backend', '.venv', 'bin', 'python3');
 }
 
 function waitForBackend(port, timeoutMs = 60000) {
@@ -212,15 +222,19 @@ async function startBackend() {
     OPENSWARM_PORT: String(backendPort),
     OPENSWARM_ELECTRON_PATH: process.execPath,
     PYTHONDONTWRITEBYTECODE: '1',
+    // PEP 540 UTF-8 mode: makes open() default to UTF-8 on Windows where
+    // the locale is otherwise cp1252. Many backend modules read UTF-8
+    // .md / .json files without an explicit encoding= argument.
+    PYTHONUTF8: '1',
   };
 
   if (isPackaged) {
-    const pythonEnvSitePackages = path.join(
-      process.resourcesPath, 'python-env', 'lib',
-      'python3.13', 'site-packages'
-    );
+    // site-packages location differs by OS — Windows has no lib/python3.13/.
+    const pythonEnvSitePackages = process.platform === 'win32'
+      ? path.join(process.resourcesPath, 'python-env', 'Lib', 'site-packages')
+      : path.join(process.resourcesPath, 'python-env', 'lib', 'python3.13', 'site-packages');
     const debuggerDir = getResourcePath('debugger');
-    env.PYTHONPATH = [projectRoot, debuggerDir, pythonEnvSitePackages].join(':');
+    env.PYTHONPATH = [projectRoot, debuggerDir, pythonEnvSitePackages].join(path.delimiter);
   }
 
   console.log(`Starting backend: ${pythonPath} on port ${backendPort}`);
@@ -369,12 +383,27 @@ function setupAutoUpdater() {
 function killBackend() {
   if (backendProcess) {
     console.log('Killing backend process...');
-    backendProcess.kill('SIGTERM');
-    setTimeout(() => {
-      if (backendProcess && !backendProcess.killed) {
-        backendProcess.kill('SIGKILL');
+    if (process.platform === 'win32') {
+      // Windows: Node's child.kill() only terminates the direct child, leaving
+      // grandchildren (e.g. the 9router node process the Python backend
+      // spawned) as orphans. Use `taskkill /T /F` to walk the process tree.
+      try {
+        require('child_process').execFileSync(
+          'taskkill', ['/PID', String(backendProcess.pid), '/T', '/F'],
+          { stdio: 'ignore' },
+        );
+      } catch (_) {
+        // taskkill failed (process may have already exited) — fall back to kill().
+        try { backendProcess.kill(); } catch (_) {}
       }
-    }, 3000);
+    } else {
+      backendProcess.kill('SIGTERM');
+      setTimeout(() => {
+        if (backendProcess && !backendProcess.killed) {
+          backendProcess.kill('SIGKILL');
+        }
+      }, 3000);
+    }
     backendProcess = null;
   }
 }
@@ -497,9 +526,11 @@ app.on('web-contents-created', (_event, contents) => {
     mainWindow &&
     contents !== mainWindow.webContents
   ) {
-    const OAUTH_POPUP_UA =
-      'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 ' +
-      '(KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36';
+    const OAUTH_POPUP_UA = process.platform === 'win32'
+      ? 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 ' +
+        '(KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36'
+      : 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 ' +
+        '(KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36';
     contents.setUserAgent(OAUTH_POPUP_UA);
   }
 
diff --git a/electron/package-lock.json b/electron/package-lock.json
index 8c15b62f..46f6003f 100644
--- a/electron/package-lock.json
+++ b/electron/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "openswarm",
-  "version": "1.0.23",
+  "version": "1.0.24",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "openswarm",
-      "version": "1.0.23",
+      "version": "1.0.24",
       "hasInstallScript": true,
       "dependencies": {
         "electron-updater": "^6.3.0",
@@ -14,6 +14,7 @@
       },
       "devDependencies": {
         "@electron/notarize": "^3.1.1",
+        "cross-env": "^7.0.3",
         "electron": "castlabs/electron-releases#v40.7.0+wvcus",
         "electron-builder": "^25.1.0"
       }
@@ -1572,6 +1573,25 @@
         "node": ">= 10"
       }
     },
+    "node_modules/cross-env": {
+      "version": "7.0.3",
+      "resolved": "https://registry.npmjs.org/cross-env/-/cross-env-7.0.3.tgz",
+      "integrity": "sha512-+/HKd6EgcQCJGh2PSjZuUitQBQynKor4wrFbRg4DtAgS1aWO+gU52xpH7M9ScGgXSYmAVS9bIJ8EzuaGw0oNAw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "cross-spawn": "^7.0.1"
+      },
+      "bin": {
+        "cross-env": "src/bin/cross-env.js",
+        "cross-env-shell": "src/bin/cross-env-shell.js"
+      },
+      "engines": {
+        "node": ">=10.14",
+        "npm": ">=6",
+        "yarn": ">=1"
+      }
+    },
     "node_modules/cross-spawn": {
       "version": "7.0.6",
       "dev": true,
diff --git a/electron/package.json b/electron/package.json
index b4ccb274..3fa33354 100644
--- a/electron/package.json
+++ b/electron/package.json
@@ -5,11 +5,13 @@
   "main": "main.js",
   "scripts": {
     "start": "electron .",
-    "dev": "ELECTRON_DEV=1 electron .",
-    "postinstall": "bash scripts/sign-vmp.sh",
-    "sign-vmp": "bash scripts/sign-vmp.sh",
+    "dev": "cross-env ELECTRON_DEV=1 electron .",
+    "postinstall": "node scripts/sign-vmp.js",
+    "sign-vmp": "node scripts/sign-vmp.js",
     "dist": "electron-builder --mac --publish never",
     "dist:publish": "electron-builder --mac --publish always",
+    "dist:win": "electron-builder --win --x64 --publish never",
+    "dist:win:publish": "electron-builder --win --x64 --publish always",
     "dist:all": "electron-builder --mac --win --linux"
   },
   "dependencies": {
@@ -18,6 +20,7 @@
   },
   "devDependencies": {
     "@electron/notarize": "^3.1.1",
+    "cross-env": "^7.0.3",
     "electron": "castlabs/electron-releases#v40.7.0+wvcus",
     "electron-builder": "^25.1.0"
   },
@@ -58,6 +61,29 @@
         }
       ]
     },
+    "win": {
+      "icon": "build/icon.ico",
+      "target": [
+        {
+          "target": "nsis",
+          "arch": ["x64"]
+        }
+      ],
+      "artifactName": "OpenSwarm-Setup-${version}-${arch}.${ext}",
+      "sign": "./build/sign-windows.js",
+      "signingHashAlgorithms": ["sha256"],
+      "signDlls": false
+    },
+    "nsis": {
+      "oneClick": true,
+      "perMachine": false,
+      "allowToChangeInstallationDirectory": false,
+      "createDesktopShortcut": true,
+      "createStartMenuShortcut": true,
+      "shortcutName": "OpenSwarm",
+      "deleteAppDataOnUninstall": false,
+      "artifactName": "OpenSwarm-Setup-${version}-${arch}.${ext}"
+    },
     "extraResources": [
       {
         "from": "build-staging/frontend",
diff --git a/electron/scripts/sign-vmp.js b/electron/scripts/sign-vmp.js
new file mode 100644
index 00000000..086f4b3e
--- /dev/null
+++ b/electron/scripts/sign-vmp.js
@@ -0,0 +1,14 @@
+// Cross-platform wrapper around sign-vmp.sh.
+// VMP signing (CastLabs Widevine) only runs on macOS. On Windows/Linux this
+// is a no-op so `npm install` doesn't blow up trying to invoke bash.
+const { spawnSync } = require('child_process');
+const path = require('path');
+
+if (process.platform !== 'darwin') {
+  console.log(`[vmp] Skipping VMP signing on ${process.platform} (macOS-only)`);
+  process.exit(0);
+}
+
+const script = path.join(__dirname, 'sign-vmp.sh');
+const result = spawnSync('bash', [script], { stdio: 'inherit' });
+process.exit(result.status ?? 0);
diff --git a/frontend/src/app/components/OnboardingModal.tsx b/frontend/src/app/components/OnboardingModal.tsx
index 0e628fe1..81244d2a 100644
--- a/frontend/src/app/components/OnboardingModal.tsx
+++ b/frontend/src/app/components/OnboardingModal.tsx
@@ -135,9 +135,33 @@ const OnboardingModal: React.FC = () => {
   const [referralSourceOther, setReferralSourceOther] = useState<string>('');
   const [connecting, setConnecting] = useState<string | null>(null);
   const [nineRouterReady, setNineRouterReady] = useState<boolean | null>(null);
+  // Providers the backend says are already authenticated. Used to show a
+  // "Connected" state on rows where the user has already linked the account.
+  // Without this the row reverts to "Connect ->" after a 30s OAuth timeout
+  // even when the backend actually completed the link.
+  const [connectedProviders, setConnectedProviders] = useState<Set<string>>(new Set());
   const pollTimerRef = useRef<any>(null);
   const msgHandlerRef = useRef<any>(null);
 
+  // Poll subscription status while the connect step is showing so the row
+  // labels reflect any post-timeout backend success and any prior connections.
+  useEffect(() => {
+    if (step !== 'connect' || !open) return;
+    let cancelled = false;
+    const refresh = async () => {
+      try {
+        const r = await fetch(`${API_BASE}/agents/subscriptions/status`);
+        const d = await r.json();
+        if (cancelled) return;
+        const conns = d?.providers?.connections || [];
+        setConnectedProviders(new Set(conns.filter((p: any) => p.isActive).map((p: any) => p.provider)));
+      } catch {}
+    };
+    refresh();
+    const id = setInterval(refresh, 4000);
+    return () => { cancelled = true; clearInterval(id); };
+  }, [step, open]);
+
   // Poll for 9Router readiness (it may still be starting when onboarding shows)
   useEffect(() => {
     let attempts = 0;
diff --git a/scripts/build-app-win.ps1 b/scripts/build-app-win.ps1
new file mode 100644
index 00000000..8aa66733
--- /dev/null
+++ b/scripts/build-app-win.ps1
@@ -0,0 +1,261 @@
+# Master build script for the OpenSwarm desktop app on Windows.
+#
+# Usage:
+#   pwsh scripts\build-app-win.ps1                Local dev build (unsigned)
+#   pwsh scripts\build-app-win.ps1 -Sign          Signed build (no publish)
+#   pwsh scripts\build-app-win.ps1 -Publish       Production build (sign + publish to GitHub Releases)
+#
+# Reads .env.windows (gitignored) for Azure Trusted Signing + GH_TOKEN if -Sign or -Publish.
+
+[CmdletBinding()]
+param(
+    [switch]$Sign,
+    [switch]$Publish
+)
+
+$ErrorActionPreference = 'Stop'
+if ($Publish) { $Sign = $true }
+
+$ScriptDir   = Split-Path -Parent $PSCommandPath
+$ProjectRoot = Split-Path -Parent $ScriptDir
+
+# --- Load .env.windows if present ---
+$EnvFile = Join-Path $ProjectRoot '.env.windows'
+if (Test-Path $EnvFile) {
+    Get-Content $EnvFile | ForEach-Object {
+        $line = $_.Trim()
+        if ($line -and -not $line.StartsWith('#') -and $line.Contains('=')) {
+            $idx = $line.IndexOf('=')
+            $name  = $line.Substring(0, $idx).Trim()
+            $value = $line.Substring($idx + 1).Trim()
+            if ($value.StartsWith('"') -and $value.EndsWith('"')) {
+                $value = $value.Substring(1, $value.Length - 2)
+            }
+            Set-Item -Path "Env:$name" -Value $value
+        }
+    }
+}
+
+Write-Host "========================================"
+Write-Host "  OpenSwarm Desktop App Builder (Windows)"
+if     ($Publish) { Write-Host "  Mode: PRODUCTION (sign + publish to GitHub Releases)" }
+elseif ($Sign)    { Write-Host "  Mode: SIGNED (sign, no publish)" }
+else              { Write-Host "  Mode: LOCAL (unsigned)" }
+Write-Host "========================================"
+Write-Host ""
+
+# --- Required env validation ---
+if ($Sign) {
+    $required = @(
+        'AZURE_TENANT_ID','AZURE_CLIENT_ID','AZURE_CLIENT_SECRET',
+        'AZURE_SIGNING_ENDPOINT','AZURE_SIGNING_ACCOUNT','AZURE_SIGNING_CERT_PROFILE'
+    )
+    if ($Publish) { $required += 'GH_TOKEN' }
+    $missing = $required | Where-Object { -not [Environment]::GetEnvironmentVariable($_) }
+    if ($missing.Count -gt 0) {
+        Write-Host "ERROR: Missing required environment variables:" -ForegroundColor Red
+        $missing | ForEach-Object { Write-Host "  - $_" }
+        Write-Host "Copy .env.windows.example to .env.windows and fill in values."
+        exit 1
+    }
+}
+
+# --- Step 0: Bundled uv/uvx (Windows zip) ---
+$UvBinDir = Join-Path $ProjectRoot 'backend\uv-bin'
+if (-not (Test-Path (Join-Path $UvBinDir 'uvx.exe'))) {
+    Write-Host "[0] Downloading uv/uvx for Windows..."
+    New-Item -ItemType Directory -Force -Path $UvBinDir | Out-Null
+    $UvUrl = 'https://github.com/astral-sh/uv/releases/latest/download/uv-x86_64-pc-windows-msvc.zip'
+    $TmpZip = Join-Path $env:TEMP "uv-win-$([guid]::NewGuid()).zip"
+    $TmpExtract = Join-Path $env:TEMP "uv-win-extract-$([guid]::NewGuid())"
+    try {
+        Invoke-WebRequest -Uri $UvUrl -OutFile $TmpZip -UseBasicParsing
+        Expand-Archive -Path $TmpZip -DestinationPath $TmpExtract -Force
+        Get-ChildItem -Path $TmpExtract -Recurse -Filter 'uv.exe'  | Select-Object -First 1 | ForEach-Object { Copy-Item $_.FullName (Join-Path $UvBinDir 'uv.exe') -Force }
+        Get-ChildItem -Path $TmpExtract -Recurse -Filter 'uvx.exe' | Select-Object -First 1 | ForEach-Object { Copy-Item $_.FullName (Join-Path $UvBinDir 'uvx.exe') -Force }
+        Write-Host "uv/uvx downloaded and bundled."
+    } finally {
+        Remove-Item -Force $TmpZip -ErrorAction SilentlyContinue
+        Remove-Item -Recurse -Force $TmpExtract -ErrorAction SilentlyContinue
+    }
+} else {
+    Write-Host "[0] uv/uvx binaries already present."
+}
+Write-Host ""
+
+# --- Step 0b: Bundle reddit-mcp-buddy via esbuild ---
+$McpBundleDir = Join-Path $ProjectRoot 'backend\mcp-bundles'
+New-Item -ItemType Directory -Force -Path $McpBundleDir | Out-Null
+$RedditBundle = Join-Path $McpBundleDir 'reddit-mcp-buddy.js'
+if (-not (Test-Path $RedditBundle)) {
+    Write-Host "[0b] Bundling reddit-mcp-buddy..."
+    $TmpDir = Join-Path $env:TEMP "openswarm-mcp-$([guid]::NewGuid())"
+    New-Item -ItemType Directory -Force -Path $TmpDir | Out-Null
+    Push-Location $TmpDir
+    try {
+        & npm install reddit-mcp-buddy --silent 2>$null
+        & npx esbuild "node_modules/reddit-mcp-buddy/dist/index.js" --bundle --platform=node --format=cjs "--outfile=$RedditBundle"
+        if ($LASTEXITCODE -ne 0) { throw "esbuild failed" }
+        Write-Host "reddit-mcp-buddy bundled."
+    } finally {
+        Pop-Location
+        Remove-Item -Recurse -Force $TmpDir -ErrorAction SilentlyContinue
+    }
+} else {
+    Write-Host "[0b] reddit-mcp-buddy bundle already present."
+}
+
+# --- Step 0c: npm MCP servers that can't be bundled ---
+$NpmServersDir = Join-Path $ProjectRoot 'backend\npm-servers'
+New-Item -ItemType Directory -Force -Path $NpmServersDir | Out-Null
+
+function Install-NpmServer($SubDir, $PackageName) {
+    $TargetDir = Join-Path $NpmServersDir $SubDir
+    $NodeModules = Join-Path $TargetDir 'node_modules'
+    if (Test-Path $NodeModules) {
+        Write-Host "[0c] $PackageName already present."
+        return
+    }
+    Write-Host "[0c] Installing $PackageName..."
+    New-Item -ItemType Directory -Force -Path $TargetDir | Out-Null
+    Push-Location $TargetDir
+    try {
+        & npm init -y *>$null
+        & npm install $PackageName --silent 2>$null
+        if ($LASTEXITCODE -ne 0) { throw "$PackageName install failed" }
+        Write-Host "$PackageName installed."
+    } finally {
+        Pop-Location
+    }
+}
+Install-NpmServer 'softeria-ms-365-mcp-server' '@softeria/ms-365-mcp-server'
+Install-NpmServer 'notionhq-notion-mcp-server' '@notionhq/notion-mcp-server'
+Write-Host ""
+
+# --- Step 1: Frontend build ---
+Write-Host "[1/5] Building frontend..."
+Push-Location (Join-Path $ProjectRoot 'frontend')
+try {
+    & npm install
+    if ($LASTEXITCODE -ne 0) { throw "npm install (frontend) failed" }
+    & npm run build
+    if ($LASTEXITCODE -ne 0) { throw "frontend build failed" }
+} finally { Pop-Location }
+if (-not (Test-Path (Join-Path $ProjectRoot 'frontend\dist\index.html'))) {
+    throw "Frontend build failed - dist\index.html not found"
+}
+Write-Host "Frontend build complete."
+Write-Host ""
+
+# --- Step 2: Python env ---
+$PythonEnv = Join-Path $ProjectRoot 'electron\python-env'
+$PythonExe = Join-Path $PythonEnv 'python.exe'
+if ((Test-Path $PythonExe) -and -not $env:OPENSWARM_REBUILD_PYTHON) {
+    Write-Host "[2/5] Python environment already present at $PythonEnv (set `$env:OPENSWARM_REBUILD_PYTHON='1' to force rebuild)."
+} else {
+    Write-Host "[2/5] Building Python environment..."
+    & (Join-Path $ScriptDir 'build-python-env-win.ps1')
+    if ($LASTEXITCODE -ne 0) { throw "Python env build failed" }
+}
+if (-not (Test-Path (Join-Path $ProjectRoot 'electron\python-env'))) {
+    throw "Python environment not found at electron\python-env\"
+}
+Write-Host "Python environment ready."
+Write-Host ""
+
+# --- Step 3: 9Router build ---
+Write-Host "[3/5] Building 9Router..."
+Push-Location (Join-Path $ProjectRoot '9router')
+try {
+    & npm install
+    if ($LASTEXITCODE -ne 0) { throw "npm install (9router) failed" }
+    & npm run build
+    if ($LASTEXITCODE -ne 0) { throw "9router build failed" }
+} finally { Pop-Location }
+$Standalone = Join-Path $ProjectRoot '9router\.next\standalone'
+if (-not (Test-Path $Standalone)) { throw "9Router build failed - .next\standalone not found" }
+$NextStatic = Join-Path $ProjectRoot '9router\.next\static'
+if (Test-Path $NextStatic) {
+    $StandaloneStatic = Join-Path $Standalone '.next\static'
+    New-Item -ItemType Directory -Force -Path (Split-Path $StandaloneStatic -Parent) | Out-Null
+    Copy-Item -Recurse -Force $NextStatic $StandaloneStatic
+}
+$NextPublic = Join-Path $ProjectRoot '9router\public'
+if (Test-Path $NextPublic) {
+    Copy-Item -Recurse -Force $NextPublic (Join-Path $Standalone 'public')
+}
+Write-Host "9Router build complete."
+Write-Host ""
+
+# --- Step 4: Snapshot source dirs into electron\build-staging\ ---
+Write-Host "[4/5] Snapshotting source directories..."
+$Staging = Join-Path $ProjectRoot 'electron\build-staging'
+if (Test-Path $Staging) { Remove-Item -Recurse -Force $Staging }
+New-Item -ItemType Directory -Force -Path $Staging | Out-Null
+
+function Copy-Excluded($Source, $Dest, $Exclude) {
+    # robocopy: built-in, fast, handles long paths.
+    $args = @($Source, $Dest, '/E', '/NJH', '/NJS', '/NDL', '/NFL', '/NP', '/MT:8')
+    foreach ($d in $Exclude.Dirs)  { $args += '/XD'; $args += $d }
+    foreach ($f in $Exclude.Files) { $args += '/XF'; $args += $f }
+    & robocopy @args | Out-Null
+    # robocopy exit codes 0–7 are success
+    if ($LASTEXITCODE -ge 8) { throw "robocopy failed ($Source -> $Dest, exit $LASTEXITCODE)" }
+    $global:LASTEXITCODE = 0
+}
+
+Copy-Excluded `
+    (Join-Path $ProjectRoot 'backend') (Join-Path $Staging 'backend') `
+    @{ Dirs = @('__pycache__','.venv','tools'); Files = @('*.pyc') }
+New-Item -ItemType Directory -Force -Path (Join-Path $Staging 'backend\data\tools') | Out-Null
+
+Copy-Excluded `
+    (Join-Path $ProjectRoot 'debugger') (Join-Path $Staging 'debugger') `
+    @{ Dirs = @('__pycache__','.venv','node_modules'); Files = @('*.pyc') }
+
+Copy-Item -Recurse -Force (Join-Path $ProjectRoot 'frontend\dist\*') (New-Item -ItemType Directory -Force -Path (Join-Path $Staging 'frontend')).FullName
+
+# 9Router standalone -> staging\9router
+Copy-Excluded $Standalone (Join-Path $Staging '9router') @{ Dirs = @(); Files = @() }
+if (Test-Path $NextStatic) {
+    $TargetStatic = Join-Path $Staging '9router\.next\static'
+    New-Item -ItemType Directory -Force -Path (Split-Path $TargetStatic -Parent) | Out-Null
+    Copy-Item -Recurse -Force $NextStatic $TargetStatic
+}
+
+Write-Host ""
+Write-Host "========================================" -BackgroundColor Green -ForegroundColor White
+Write-Host "  SOURCE SNAPSHOT COMPLETE              " -BackgroundColor Green -ForegroundColor White
+Write-Host "  Safe to modify your codebase now.     " -BackgroundColor Green -ForegroundColor White
+Write-Host "========================================" -BackgroundColor Green -ForegroundColor White
+Write-Host ""
+
+# --- Step 5: Package with electron-builder ---
+Write-Host "[5/5] Packaging with electron-builder..."
+Push-Location (Join-Path $ProjectRoot 'electron')
+try {
+    & npm install
+    if ($LASTEXITCODE -ne 0) { throw "npm install (electron) failed" }
+
+    if (-not $Sign) {
+        $env:CSC_IDENTITY_AUTO_DISCOVERY = 'false'
+    }
+
+    if ($Publish) {
+        & npx electron-builder --win --x64 --publish always
+    } else {
+        & npx electron-builder --win --x64 --publish never
+    }
+    if ($LASTEXITCODE -ne 0) { throw "electron-builder failed" }
+} finally { Pop-Location }
+
+Remove-Item -Recurse -Force $Staging -ErrorAction SilentlyContinue
+
+Write-Host ""
+Write-Host "========================================"
+Write-Host "  Build Complete!"
+Write-Host "========================================"
+Write-Host ""
+Write-Host "Output files:"
+Get-ChildItem -Path (Join-Path $ProjectRoot 'electron\dist') -Filter '*.exe' -ErrorAction SilentlyContinue | Format-Table Name, Length, LastWriteTime
+Get-ChildItem -Path (Join-Path $ProjectRoot 'electron\dist') -Filter '*.zip' -ErrorAction SilentlyContinue | Format-Table Name, Length, LastWriteTime
diff --git a/scripts/build-python-env-win.ps1 b/scripts/build-python-env-win.ps1
new file mode 100644
index 00000000..a33539ab
--- /dev/null
+++ b/scripts/build-python-env-win.ps1
@@ -0,0 +1,100 @@
+# Build an embedded Windows Python environment for the Electron app.
+#
+# Downloads a standalone CPython build for Windows from python-build-standalone,
+# installs backend deps, and leaves it under electron\python-env\.
+# Bundled into the .exe installer by electron-builder via extraResources.
+
+$ErrorActionPreference = 'Stop'
+
+$ScriptDir   = Split-Path -Parent $PSCommandPath
+$ProjectRoot = Split-Path -Parent $ScriptDir
+$ElectronDir = Join-Path $ProjectRoot 'electron'
+$PythonEnvDir = Join-Path $ElectronDir 'python-env'
+
+$PythonVersion     = '3.13'
+$PythonFullVersion = '3.13.2'
+$ReleaseTag        = '20250212'
+$PlatformTag       = 'x86_64-pc-windows-msvc-shared'
+$Tarball           = "cpython-$PythonFullVersion+$ReleaseTag-$PlatformTag-install_only_stripped.tar.gz"
+$DownloadUrl       = "https://github.com/indygreg/python-build-standalone/releases/download/$ReleaseTag/$Tarball"
+
+Write-Host "=== Building Windows Python Environment ==="
+Write-Host "Architecture: x64 ($PlatformTag)"
+Write-Host "Python: $PythonFullVersion"
+
+if (Test-Path $PythonEnvDir) {
+    Write-Host "Removing old python-env..."
+    Remove-Item -Recurse -Force $PythonEnvDir
+}
+
+$TempDir = New-Item -ItemType Directory -Path (Join-Path $env:TEMP "openswarm-pyenv-$([guid]::NewGuid())") -Force
+try {
+    $ArchivePath = Join-Path $TempDir.FullName 'python.tar.gz'
+    Write-Host "Downloading standalone Python..."
+    Write-Host "URL: $DownloadUrl"
+    Invoke-WebRequest -Uri $DownloadUrl -OutFile $ArchivePath -UseBasicParsing
+
+    Write-Host "Extracting..."
+    # tar is built-in on Windows 10+ (bsdtar) and handles .tar.gz natively.
+    & tar -xzf $ArchivePath -C $TempDir.FullName
+    if ($LASTEXITCODE -ne 0) { throw "tar extract failed" }
+
+    $Extracted = Join-Path $TempDir.FullName 'python'
+    if (-not (Test-Path $Extracted)) {
+        Get-ChildItem $TempDir.FullName | Format-Table | Out-String | Write-Host
+        throw "Expected extracted directory at $Extracted"
+    }
+
+    Move-Item -Path $Extracted -Destination $PythonEnvDir
+    Write-Host "Python installed to $PythonEnvDir"
+} finally {
+    if (Test-Path $TempDir.FullName) {
+        Remove-Item -Recurse -Force $TempDir.FullName
+    }
+}
+
+$PythonBin = Join-Path $PythonEnvDir 'python.exe'
+if (-not (Test-Path $PythonBin)) { throw "python.exe not found at $PythonBin" }
+
+Write-Host "Python binary: $PythonBin"
+& $PythonBin --version
+
+# Ensure pip is present
+& $PythonBin -m pip --version 2>$null
+if ($LASTEXITCODE -ne 0) {
+    Write-Host "Installing pip..."
+    & $PythonBin -m ensurepip --upgrade
+    if ($LASTEXITCODE -ne 0) { throw "ensurepip failed" }
+}
+
+Write-Host "Installing backend dependencies..."
+& $PythonBin -m pip install --upgrade pip
+if ($LASTEXITCODE -ne 0) { throw "pip upgrade failed" }
+& $PythonBin -m pip install -r (Join-Path $ProjectRoot 'backend\requirements.txt')
+if ($LASTEXITCODE -ne 0) { throw "pip install requirements failed" }
+
+Write-Host "Installing debugger module..."
+& $PythonBin -m pip install (Join-Path $ProjectRoot 'debugger')
+if ($LASTEXITCODE -ne 0) { throw "pip install debugger failed" }
+
+Write-Host "Verifying claude-agent-sdk..."
+& $PythonBin -c "import claude_agent_sdk; print('claude-agent-sdk installed')"
+if ($LASTEXITCODE -ne 0) { throw "claude-agent-sdk verification failed" }
+
+# Cleanup
+Write-Host "Cleaning up..."
+Get-ChildItem -Path $PythonEnvDir -Recurse -Force -Directory `
+    | Where-Object { $_.Name -in @('__pycache__','tests','test') } `
+    | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue
+Get-ChildItem -Path $PythonEnvDir -Recurse -Force -Filter '*.pyc' `
+    | Remove-Item -Force -ErrorAction SilentlyContinue
+
+$Size = (Get-ChildItem -Path $PythonEnvDir -Recurse -File `
+    | Measure-Object -Property Length -Sum).Sum
+$SizeMB = [math]::Round($Size / 1MB, 1)
+
+Write-Host ""
+Write-Host "=== Python Environment Ready ==="
+Write-Host "Location: $PythonEnvDir"
+Write-Host ("Size: {0} MB" -f $SizeMB)
+Write-Host ""